WorldWideScience

Sample records for conversion system development

  1. The Research and Development of the Radioisotope Energy Conversion System

    International Nuclear Information System (INIS)

    Steinfelds, E.V.; Ghosh, T.K.; Prelas, M.A.; Tompson, R.V.; Loyalka, S.K.

    2001-01-01

    The project of developing radioisotope energy conversion system (RECS) involves analytical computational assisted design and modeling and also laboratory research. The computational analysis consists of selecting various geometries and materials for the main RECS container and the internally located radioisotope, computing the fluxes of the beta (-) particles and of the visible (or ultraviolet) photons produced by the beta (-) s, computing the transport of these photons to the photovoltaic cells, and computing the overall efficiency of useful conversion of the radioisotope power

  2. Development of Electro-Microbial Carbon Capture and Conversion Systems

    KAUST Repository

    Al Rowaihi, Israa S.

    2017-05-01

    Carbon dioxide is a viable resource, if used as a raw material for bioprocessing. It is abundant and can be collected as a byproduct from industrial processes. Globally, photosynthetic organisms utilize around 6’000 TW (terawatt) of solar energy to fix ca. 800 Gt (gigaton) of CO2 in the planets largest carbon-capture process. Photosynthesis combines light harvesting, charge separation, catalytic water splitting, generation of reduction equivalents (NADH), energy (ATP) production and CO2 fixation into one highly interconnected and regulated process. While this simplicity makes photosynthetic production of commodity interesting, yet photosynthesis suffers from low energy efficiency, which translates in an extensive footprint for solar biofuels production conditions that store < 2% of solar energy. Electron transfer processes form the core of photosynthesis. At moderate light intensity, the electron transport chains reach maximum transfer rates and only work when photons are at appropriate wavelengths, rendering the process susceptible to oxidative damage, which leads to photo-inhibition and loss of efficiency. Based on our fundamental analysis of the specialized tasks in photosynthesis, we aimed to optimize the efficiency of these processes separately, then combine them in an artificial photosynthesis (AP) process that surpasses the low efficiency of natural photosynthesis. Therefore, by combining photovoltaic light harvesting with electrolytic water splitting or CO2 reduction in combination with microbiological conversion of electrochemical products to higher valuable compounds, we developed an electro-microbial carbon capture and conversion setups that capture CO2 into the targeted bioplastic; polyhydroxybutyrate (PHB). Based on the type of the electrochemical products, and the microorganism that either (i) convert products formed by electrochemical reduction of CO2, e.g. formate (using inorganic cathodes), or (ii) use electrochemically produced H2 to reduce CO2

  3. Research and Technology Activities Supporting Closed-Brayton-Cycle Power Conversion System Development

    Science.gov (United States)

    Barrett, Michael J.

    2004-01-01

    The elements of Brayton technology development emphasize power conversion system risk mitigation. Risk mitigation is achieved by demonstrating system integration feasibility, subsystem/component life capability (particularly in the context of material creep) and overall spacecraft mass reduction. Closed-Brayton-cycle (CBC) power conversion technology is viewed as relatively mature. At the 2-kWe power level, a CBC conversion system Technology Readiness Level (TRL) of six (6) was achieved during the Solar Dynamic Ground Test Demonstration (SD-GTD) in 1998. A TRL 5 was demonstrated for 10 kWe-class CBC components during the development of the Brayton Rotating Unit (BRU) from 1968 to 1976. Components currently in terrestrial (open cycle) Brayton machines represent TRL 4 for similar uses in 100 kWe-class CBC space systems. Because of the baseline component and subsystem technology maturity, much of the Brayton technology task is focused on issues related to systems integration. A brief description of ongoing technology activities is given.

  4. Solar energy conversion systems

    CERN Document Server

    Brownson, Jeffrey R S

    2013-01-01

    Solar energy conversion requires a different mind-set from traditional energy engineering in order to assess distribution, scales of use, systems design, predictive economic models for fluctuating solar resources, and planning to address transient cycles and social adoption. Solar Energy Conversion Systems examines solar energy conversion as an integrative design process, applying systems thinking methods to a solid knowledge base for creators of solar energy systems. This approach permits different levels of access for the emerging broad audience of scientists, engineers, architects, planners

  5. Development of fluoric compound treatment system in conversion for recycle in metal industry

    International Nuclear Information System (INIS)

    Kim, P.O.; Cho, N.C.

    1998-01-01

    Korea Nuclear Fuel Company (KNFC) has been operating AUC conversion process from UF 6 to UO 2 from 1990. In 1997, KNFC constructed another conversion line called dry conversion to meet the increasing demand for nuclear fuel fabrication. In the dry conversion, two kinds of hydrofluoric acid (HF) are produced as a by-product. The first one is 50% concentration HF and the other one is diluted HF ranging from 10% to 49%. The high concentration HF can be used in metal industry, but there is no use for diluted one. The diluted HF should be disposed of as liquid waste after some treatment. To solve this problem we have developed the process to convert the diluted hydrofluoric acid to the sodium fluoride, which is readily used in the metal industry. By developing the process we could make a contribution to the environment as well as cost reduction in manufacturing nuclear fuel. (author)

  6. Development of polarized beam conversion system for the linear collider complex

    International Nuclear Information System (INIS)

    Viilleval'd, G.S.; Vsevolozhskaya, T.A.; Karasyuk, V.N.; Sil'vestrov, G.I.; Chernyakin, A.D.

    1983-01-01

    Results of development of the polarized beam conversion system for the 150 GeV linear collider aiming at the linear collider operation with a high repetition rate (approximately 10 Hz), are presented. It is shown, that the conversion can be realized by means of ondulator radiation. Structurally, the spiral ondulator is two identical solenoids, inserted in each other in such a way, that their winding turns are alternating in the direction along the axis and they are supplied by countercurrents. The main parameters of the ondulator are as follows : winding pitch -0.7 cm, the ondulator length 150 m. For generation a field of the intensity 5 kOe it has been suggested that solenoids should be supplied by sinusoidal pulse current of duration approximately 200 μs. It is shown, that the introduction of iron into solenoid increases the efficiency by a factor of 2.1 and 2.7 in the ondulator with iron only in interloop gaps and with the addition of iron locking magnetic counterflow

  7. Wind energy conversion system

    Science.gov (United States)

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  8. Development of large scale wind energy conservation system. Development of large scale wind energy conversion system; Ogata furyoku hatsuden system no kaihatsu. Ogata furyoku hatsuden system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for development of large scale wind energy conversion system. The study on technological development of key components evaluates performance of, and confirms reliability and applicability of, hydraulic systems centered by those equipped with variable pitch mechanisms and electrohydraulic servo valves that control them. The study on blade conducts fatigue and crack-propagation tests, which show that the blades developed have high strength. The study on speed-increasing gear conducts load tests, confirming the effects of reducing vibration and noise by modification of the gear teeth. The study on NACELLE cover conducts vibration tests to confirm its vibration characteristics, and analyzes three-dimensional vibration by the finite element method. Some components for a 500kW commercial wind mill are fabricated, including rotor heads, variable pitch mechanisms, speed-increasing gears, YAW systems, and hydraulic control systems. The others fabricated include a remote supervisory control system for maintenance, system to integrate the wind mill into a power system, and electrical control devices in which site conditions, such as atmospheric temperature and lightening, are taken into consideration.

  9. Development of a system for characterizing biomass quality of lignocellulosic feedstocks for biochemical conversion

    Science.gov (United States)

    Murphy, Patrick Thomas

    The purpose of this research was twofold: (i) to develop a system for screening lignocellulosic biomass feedstocks for biochemical conversion to biofuels and (ii) to evaluate brown midrib corn stover as feedstock for ethanol production. In the first study (Chapter 2), we investigated the potential of corn stover from bm1-4 hybrids for increased ethanol production and reduced pretreatment intensity compared to corn stover from the isogenic normal hybrid. Corn stover from hybrid W64A X A619 and respective isogenic bm hybrids was pretreated by aqueous ammonia steeping using ammonium hydroxide concentrations from 0 to 30%, by weight, and the resulting residues underwent simultaneous saccharification and cofermentation (SSCF) to ethanol. Dry matter (DM) digested by SSCF increased with increasing ammonium hydroxide concentration across all genotypes (P>0.0001) from 277 g kg-1 DM in the control to 439 g kg-1 DM in the 30% ammonium hydroxide pretreatment. The bm corn stover materials averaged 373 g kg-1 DM of DM digested by SSCF compared with 335 g kg-1 DM for the normal corn stover (Pdetergent fiber (NDF) as a cell-wall isolation procedure, and (iii) elimination of the fermentation organism in the SSCF procedures used to determine biochemically available carbohydrates. The original and the HTP assay methods were compared using corn cobs, hybrid poplar, kenaf, and switchgrass. Biochemically available carbohydrates increased with the HTP methods in the corn cobs, hybrid poplar, and switchgrass, but remained the same in the kenaf. Total available carbohydrates increased and unavailable carbohydrates decreased with the HTP methods in the corn cobs and switchgrass and remained the same in the hybrid poplar and kenaf. There were no differences in total carbohydrates (CT) between the two methods. The final study evaluated the variability of biomass quality parameters in a set of corn stover samples, and developed calibration equations for determining parameter values using near

  10. Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, G.L.

    2005-10-03

    This report documents the work performed during the first phase of the National Aeronautics and Space Administration (NASA), National Research Announcement (NRA) Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs. The document includes an optimization of both 100-kW{sub e} and 250-kW{sub e} (at the propulsion unit) Rankine cycle power conversion systems. In order to perform the mass optimization of these systems, several parametric evaluations of different design options were investigated. These options included feed and reheat, vapor superheat levels entering the turbine, three different material types, and multiple heat rejection system designs. The overall masses of these Nb-1%Zr systems are approximately 3100 kg and 6300 kg for the 100- kW{sub e} and 250-kW{sub e} systems, respectively, each with two totally redundant power conversion units, including the mass of the single reactor and shield. Initial conceptual designs for each of the components were developed in order to estimate component masses. In addition, an overall system concept was presented that was designed to fit within the launch envelope of a heavy lift vehicle. A technology development plan is presented in the report that describes the major efforts that are required to reach a technology readiness level of 6. A 10-year development plan was proposed.

  11. Development of nuclear technologies and conversion of nuclear weapon testing system infrastructure in Kazakhstan

    International Nuclear Information System (INIS)

    Cherepnin, Yu.; Takibaev, Zh.

    2000-01-01

    The article gives a brief description of the work done by the National Nuclear Center of the Republic of Kazakhstan in development of nuclear technology and conversion of nuclear weapon testing infrastructure in Kazakhstan. Content and trends of works are as follows: 1. Peaceful use of all physical facilities, created earlier for nuclear tests in Kazakhstan; 2. Development of methods and technologies for safe nuclear reactors use; 3. Examination of different materials in field of great neutron flow for thermonuclear reactor's first wall development; 4. Liquidation of all wells, which were formed in the results of underground nuclear explosions in Degelen mountain massif of former Semipalatinsk test site; 5. Study of consequences of nuclear tests in West Kazakhstan (territory of Azgir test site and Karachaganak oil field); 6. Study of radiological situation on the Semipalatinsk test site and surrounding territories; 7. Search of ways for high-level radioactive wastes disposal; 8. Construction of safe nuclear power plants in Kazakhstan

  12. Flow energy conversion system

    International Nuclear Information System (INIS)

    Sargsyan, R.A.

    2011-01-01

    A cost-effective hydropower system called here Flow Energy Converter was developed, patented, manufactured and tested for water pumping, electricity generation and other purposes especially useful for the rural communities. The system consists of water-driven turbine with plane-surface blades, power transmission means and pump and/or generator. Working sample of the Flow Energy Converter was designed and manufactured at the Institute of Radio Physics and Electronics

  13. Development of optimal enzymatic and microbial conversion systems for biofuel production

    Science.gov (United States)

    Aramrueang, Natthiporn

    The increase in demand for fuels, along with the concerns over the depletion of fossil fuels and the environmental problems associated with the use of the petroleum-based fuels, has driven the exploitation of clean and renewable energy. Through a collaboration project with Mendota Bioenergy LLC to produce advanced biofuel from sugar beet and other locally grown crops in the Central Valley of California through demonstration and commercial-scale biorefineries, the present study focused on the investigation of selected potential biomass as biofuel feedstock and development of bioconversion systems for sustainable biofuel production. For an efficient biomass-to-biofuel conversion process, three important steps, which are central to this research, must be considered: feedstock characterization, enzymatic hydrolysis of the feedstock, and the bioconversion process. The first part of the research focused on the characterization of various lignocellulosic biomass as feedstocks and investigated their potential ethanol yields. Physical characteristics and chemical composition were analyzed for four sugar beet varieties, three melon varieties, tomato, Jose tall wheatgrass, wheat hay, and wheat straw. Melons and tomato are those products discarded by the growers or processors due to poor quality. The mass-based ethanol potential of each feedstock was determined based on the composition. The high sugar-containing feedstocks are sugar beet roots, melons, and tomato, containing 72%, 63%, and 42% average soluble sugars on a dry basis, respectively. Thus, for these crops, the soluble sugars are the main substrate for ethanol production. The potential ethanol yields, on average, for sugar beet roots, melons, and tomato are 591, 526, and 448 L ethanol/metric ton dry basis (d.b.), respectively. Lignocellulosic biomass, including Jose Tall wheatgrass and wheat straw, are composed primarily of cellulose (27-39% d.b.) and hemicellulose (26-30% d.b.). The ethanol yields from these

  14. HYDROKINETIC ENERGY CONVERSION SYSTEMS: PROSPECTS ...

    African Journals Online (AJOL)

    eobe

    Hydrokinetic energy conversion systems utilize the kinetic energy of flowing water bodies with little or no head to generate ... generator. ... Its principle of operation is analogous to that of wind ..... Crisis-solar and wind power systems, 2009,.

  15. GEO-TEP. Development of thermoelectric materials for geothermal energy conversion systems. Final report 2008

    Energy Technology Data Exchange (ETDEWEB)

    Bocher, L.; Weidenkaff, A.

    2008-07-01

    Geothermal heat can be directly converted into electricity by using thermoelectric converters. Thermoelectric conversion relies on intrinsic materials properties which have to be optimised. In this work novel environmentally friendly and stable oxide ceramics were developed to fulfil this task. Thus, manganate phases were studied regarding their potential thermoelectric properties for converting geothermal heat into electricity. Perovskite-type phases were synthesized by applying different methods: the ceramic route, and innovative synthesis routes such as the 'chimie douce' method by bulk thermal decomposition of the citrate precursor or using an USC process, and also the polyol-mediated synthesis route. The crystal structures of the manganate phases are evaluated by XRPD, NPD, and ED techniques while specific microstructures such as twinned domains are highlighted by HRTEM imaging. Besides, the thermal stability of the Mn-oxide phases in air atmosphere are controlled over a wide temperature range (T < 1300 K). The thermoelectric figure of merit ZT was enhanced from 0.021 to 0.3 in a broad temperature range for the studied phases which makes these phases the best perovskitic candidates as n-type polycrystalline thermoelectric materials operating in air at high temperatures. (author)

  16. Ocean thermal energy conversion (OTEC) power system development. Preliminary design report, Appendices, Part 1 (Final)

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the developed computer models, water system dynamic studies, miscellaneous performance analysis, materials and processes, detailed equipment lists, turbine design studies, tube cleaner design, ammonia leak detection, and heat exchanger design supporting data. (WHK)

  17. Technical characteristic analysis of wind energy conversion systems for sustainable development

    International Nuclear Information System (INIS)

    BoroumandJazi, G.; Rismanchi, B.; Saidur, R.

    2013-01-01

    Highlights: ► Identifying the required technical characteristics of sustainable wind power system. ► Observing Weibull probability function and artificial neural networks for reliability. ► Daily/monthly generation data are used to investigate the system’s availability. - Abstract: Wind energy as a clean, environmentally friendly and cost effective renewable energy resource, is taken into consideration by many developed and developing countries as a promising means to provide electrical energy. In feasibility study stage of the wind energy systems, the sustainability analysis is one of the main issues that can assure the investors and stockholders to invest in this renewable energy. Since a system can be truly sustainable by achieving the energetic, ecological and economic sustainability, the present study will focus on the technical characteristics and performance analysis of the wind energy systems. The relations between reliability, availability, energy and exergy efficiency, risk management and the environmental impact of the wind energy systems are investigated in the context of this study. It is concluded that the wind characteristics data and the wind speed are the main effective parameters on its reliability and availability. It is also revealed that considering the system loss, exergy efficiency results of the wind energy systems are more reliable than the energy efficiencies. Due to avoid future failure of the systems, the causes of the failure are investigated and it was concluded that the structural failures caused by storms and strong winds are known as the most prevalent failures

  18. Development of high conversion boiling water reactor

    International Nuclear Information System (INIS)

    Yamashita, Jun-ichi; Mochida, Takaaki; Uchikawa, Sadao.

    1988-01-01

    It is expected that the period of LWRs being the main source of electric power supply becomes long, therefore, the development of next generation LWRs placing emphasis on the effective utilization of uranium resources and the improvement of economical efficiency is necessary. In this paper, as the next generation BWRs subsequent to ABWRs, the concept of the core of high conversion type BWRs is reported, in which emphasis is placed on the saving of natural uranium resources by raising the rate of conversion to plutonium. This core is that of realizing the high rate of conversion by utilizing the void in the core, which is the feature of BWRs, and the case of making the change of the core structure relatively small by using cross type control rods and the case of changing the core structure for further heightening the rate of conversion and making control rods into cluster type are described. In order to meet the demand like this, Hitachi Ltd. has engaged in the development of the concept of the core of next generation LWRs. In the high conversion type BWRs, there is not large change in the reactor system and turbine system from the current BWRs. The features and the concept of the core of high conversion type BWRs are described. (Kako, I.)

  19. Biological conversion system

    Science.gov (United States)

    Scott, C.D.

    A system for bioconversion of organic material comprises a primary bioreactor column wherein a biological active agent (zymomonas mobilis) converts the organic material (sugar) to a product (alcohol), a rejuvenator column wherein the biological activity of said biological active agent is enhanced, and means for circulating said biological active agent between said primary bioreactor column and said rejuvenator column.

  20. Photovoltaic Energy Conversion Systems

    DEFF Research Database (Denmark)

    Kouro, Samir; Wu, Bin; Abu-Rub, Haitham

    2014-01-01

    This chapter presents a comprehensive overview of grid-connected PV systems, including power curves, grid-connected configurations, different converter topologies (both single- and three-phase), control schemes, MPPT, and anti-islanding detection methods. The focus of the chapter has been on the ...

  1. Wind Energy Conversion Systems Technology and Trends

    CERN Document Server

    2012-01-01

    Wind Energy Conversion System covers the technological progress of wind energy conversion systems, along with potential future trends. It includes recently developed wind energy conversion systems such as multi-converter operation of variable-speed wind generators, lightning protection schemes, voltage flicker mitigation and prediction schemes for advanced control of wind generators. Modeling and control strategies of variable speed wind generators are discussed, together with the frequency converter topologies suitable for grid integration. Wind Energy Conversion System also describes offshore farm technologies including multi-terminal topology and space-based wind observation schemes, as well as both AC and DC based wind farm topologies. The stability and reliability of wind farms are discussed, and grid integration issues are examined in the context of the most recent industry guidelines. Wind power smoothing, one of the big challenges for transmission system operators, is a particular focus. Fault ride th...

  2. Development and modelisation of a hydro-power conversion system based on vortex induced vibration

    Science.gov (United States)

    Lefebure, David; Dellinger, Nicolas; François, Pierre; Mosé, Robert

    2016-11-01

    The Vortex Induced Vibration (VIV) phenomenon leads to mechanical issues concerning bluff bodies immerged in fluid flows and have therefore been studied by numerous authors. Moreover, an increasing demand for energy implies the development of alternative, complementary and renewable energy solutions. The main idea of EauVIV project consists in the use of VIV rather than its deletion. When rounded objects are immerged in a fluid flow, vortices are formed and shed on their downstream side, creating a pressure imbalance resulting in an oscillatory lift. A convertor modulus consists of an elastically mounted, rigid cylinder on end-springs, undergoing flow- induced motion when exposed to transverse fluid-flow. These vortices induce cyclic lift forces in opposite directions on the circular bar and cause the cylinder to vibrate up and down. An experimental prototype was developed and tested in a free-surface water channel and is already able to recover energy from free-stream velocity between 0.5 and 1 m.s -1. However, the large number of parameters (stiffness, damping coefficient, velocity of fluid flow, etc.) associated with its performances requires optimization and we choose to develop a complete tridimensionnal numerical model solution. A 3D numerical model has been developed in order to represent the real system behavior and improve it through, for example, the addition of parallel cylinders. The numerical model build up was carried out in three phases. The first phase consists in establishing a 2D model to choose the turbulence model and quantify the dependence of the oscillations amplitudes on the mesh size. The second corresponds to a 3D simulation with cylinder at rest in first time and with vertical oscillation in a second time. The third and final phase consists in a comparison between the experimental system dynamic behavior and its numerical model.

  3. Autonomous renewable energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Valtchev, V. [Technical University of Varna (Bulgaria). Dept. of Electronics; Bossche, A. van den; Ghijselen, J.; Melkebeek, J. [University of Gent (Belgium). Dept. of Electrical Power Engineering

    2000-02-01

    This paper briefly reviews the need for renewable power generation and describes a medium-power Autonomous Renewable Energy Conversion System (ARECS), integrating conversion of wind and solar energy sources. The objectives of the paper are to extract maximum power from the proposed wind energy conversion scheme and to transfer this power and the power derived by the photovoltaic system in a high efficiency way to a local isolated load. The wind energy conversion operates at variable shaft speed yielding an improved annual energy production over constant speed systems. An induction generator (IG) has been used because of its reduced cost, robustness, absence of separate DC source for excitation, easier dismounting and maintenance. The maximum energy transfer of the wind energy is assured by a simple and reliable control strategy adjusting the stator frequency of the IG so that the power drawn is equal to the peak power production of the wind turbine at any wind speed. The presented control strategy also provides an optimal efficiency operation of the IG by applying a quadratic dependence between the IG terminal voltage and frequency V {approx} f{sup 2}. For improving the total system efficiency, high efficiency converters have been designed and implemented. The modular principle of the proposed DC/DC conversion provides the possibility for modifying the system structure depending on different conditions. The configuration of the presented ARECS and the implementation of the proposed control algorithm for optimal power transfer are fully discussed. The stability and dynamic performance as well as the different operation modes of the proposed control and the operation of the converters are illustrated and verified on an experimental prototype. (author)

  4. Ocean thermal energy conversion power system development-I. Phase I. Preliminary design report. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-18

    The results of a conceptual and preliminary design study of Ocean Thermal Energy Conversion (OTEC) closed loop ammonia power system modules performed by Lockheed Missiles and Space Company, Inc. (LMSC) are presented. This design study is the second of 3 tasks in Phase I of the Power System Development-I Project. The Task 2 objectives were to develop: 1) conceptual designs for a 40 to 50-MW(e) closed cycle ammonia commercial plant size power module whose heat exchangers are immersed in seawater and whose ancillary equipments are in a shirt sleeve environment; preliminary designs for a modular application power system sized at 10-MW(e) whose design, construction and material selection is analogous to the 50 MW(e) module, except that titanium tubes are to be used in the heat exchangers; and 3) preliminary designs for heat exchanger test articles (evaporator and condenser) representative of the 50-MW(e) heat exchangers using aluminum alloy, suitable for seawater service, for testing on OTEC-1. The reference ocean platform was specified by DOE as a surface vessel with the heat exchanger immersed in seawater to a design depth of 0 to 20 ft measured from the top of the heat exchanger. For the 50-MW(e) module, the OTEC 400-MW(e) Plant Ship, defined in the Platform Configuration and Integration study, was used as the reference platform. System design, performance, and cost are presented. (WHK)

  5. Ocean thermal energy conversion (OTEC). Power system development. Preliminary design report, final

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The preliminary design of the 10 MWe OTEC power module and the 200 kWe test articles is given in detail. System operation and performance; power system cost estimates; 10 MWe heat exchangers; 200 kWe heat exchanger articles; biofouling control;ammonia leak detection, and leak repair; rotating machinery; support subsystem; instrumentation and control; electrical subsystem; installation approach; net energy and resource analysis; and operability, maintainability, and safety are discussed. The conceptual design of the 40 MWe electrical power system includes four or five 10 MWe modules as designed for the 10 MWe pilot plant. (WHK)

  6. DEVELOPMENT OF AUTOMATED SPEECH RECOGNITION SYSTEM FOR EGYPTIAN ARABIC PHONE CONVERSATIONS

    Directory of Open Access Journals (Sweden)

    A. N. Romanenko

    2016-07-01

    Full Text Available The paper deals with description of several speech recognition systems for the Egyptian Colloquial Arabic. The research is based on the CALLHOME Egyptian corpus. The description of both systems, classic: based on Hidden Markov and Gaussian Mixture Models, and state-of-the-art: deep neural network acoustic models is given. We have demonstrated the contribution from the usage of speaker-dependent bottleneck features; for their extraction three extractors based on neural networks were trained. For their training three datasets in several languageswere used:Russian, English and differentArabic dialects.We have studied the possibility of application of a small Modern Standard Arabic (MSA corpus to derive phonetic transcriptions. The experiments have shown that application of the extractor obtained on the basis of the Russian dataset enables to increase significantly the quality of the Arabic speech recognition. We have also stated that the usage of phonetic transcriptions based on modern standard Arabic decreases recognition quality. Nevertheless, system operation results remain applicable in practice. In addition, we have carried out the study of obtained models application for the keywords searching problem solution. The systems obtained demonstrate good results as compared to those published before. Some ways to improve speech recognition are offered.

  7. Ocean thermal energy conversion power system development. Final design report: PSD-I, Phase II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-06-30

    The PSD-I program provides a heat exchanger sytem consisting of an evaporator, condenser and various ancillaries with ammonia used as a working fluid in a closed simulated Rankine cycle. It is to be installed on the Chepachet Research Vessel for test and evaluation of a number of OTEC concepts in a true ocean environment. It is one of several test articles to be tested. Primary design concerns include control of biofouling, corrosion and erosion of aluminum tubes, selection of materials, and the development of a basis for scale-up to large heat exchangers so as to ultimately demonstrate economic feasibility on a commercial scale. The PSD-I test article is devised to verify thermodynamic, environmental, and mechanical performance of basic design concepts. The detailed design, development, fabrication, checklist, delivery, installation support, and operation support for the Test Article Heat Exchangers are described. (WHK)

  8. Development of a Performance Analysis Code for the Off-design conditions of a S-CO2 Brayton Cycle Energy Conversion System

    International Nuclear Information System (INIS)

    Yoo, Yong-Hwan; Cha, Jae-Eun; Lee, Tae-Ho; Eoh, Jae-Hyuk; Kim, Seong-O

    2008-01-01

    For the development of a supercritical carbon dioxide (S-CO2) Brayton cycle energy conversion system coupled to KALIMER-600, a thermal balance has been established on 100% power operating conditions including all the reactor system models such as a primary heat transport system (PHTS), an intermediate heat transport system (IHTS), and an energy conversion system. The S-CO2 Brayton cycle energy conversion system consists of a sodium-CO2 heat exchanger (Hx), turbine, high temperature recuperate (HTR), low temperature recuperate (LTR), precooler, compressor no.1, and compressor no.2. Two compressors were employed to avoid a sharp change of the physical properties near their critical point with a corresponding pressure. The component locations and their operating conditions are illustrated. Energy balance of the power conversion system in KALIMER-600 was designed with the full power condition of each component. Therefore, to predict the off-design conditions and to evaluate each component, an off-design performance analysis code should be accomplished. An off-design performance analysis could be classified into overall system control logic and local system control logic. The former means that mass flow rate and power are controlled by valves, and the latter implies that a bypass or inventory control is an admitted system balance. The ultimate goal of this study is development of the overall system control logic

  9. EPR's energy conversion system. Alstom's solutions

    International Nuclear Information System (INIS)

    Ledermann, P.

    2009-01-01

    ARABELLE steam turbines have been developed by Alstom to be used as the energy conversion system of light water reactors with high output power like the N4 PWR and the EPR. ARABELLE turbines cumulate 200.000 hours of service with a reliability ratio of 99.97 per cent. This series of slides presents the main features of the turbine including: the use of the simple flux, the very large shape of low pressure blades, the technology of welded rotors. The other main equipment like the alternator, the condenser, the moisture separator-reheaters, the circulating pumps that Alstom integrates in the energy conversion system have benefited with technological improvements that are also presented. (A.C.)

  10. Measuring Online Dialogic Conversations: A Scale Development

    DEFF Research Database (Denmark)

    Romenti, Stefania; Valentini, Chiara; Murtarelli, Grazia

    2016-01-01

    Purpose: The scope of this paper is to develop and test a measurement scale for assessing the quality of dialogic conversations among companies and digital publics in social media. It is argued that dialogic conversations are the drivers of dialogic engagement and the result of dialogic...... interactivity. Dialogic conversations are defined as sequences of communicative actions and counteractions taken by social actors for different purposes based on specific linguistic choices and characterised by diverse communicative approaches and the role played by the involved parties. Design....../methodology/approach: A multidimensional scale for measuring dialogic conversations is developed from relevant literature concerning dialogue and public engagement in the fields of corporate communication, public relations, management studies and conversation analysis. The scale was pre-tested to redefine and purify it from irrelevant...

  11. Flexible Conversion Ratio Fast Reactor Systems Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Neil Todreas; Pavel Hejzlar

    2008-06-30

    Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

  12. Flexible Conversion Ratio Fast Reactor Systems Evaluation

    International Nuclear Information System (INIS)

    Neil Todreas; Pavel Hejzlar

    2008-01-01

    Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores treated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcome the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better thermal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor

  13. Development of uranium milling and conversion

    International Nuclear Information System (INIS)

    Takada, Shingo; Hirono, Shuichiro.

    1983-11-01

    The development and improvement of uranium milling and refining producing uranium tetrafluoride from ores by the wet process, without producing yellowcake as an intermediate product, have been carried out for over ten years with a small pilot plant (50 t-ore/day). In the past several years, a process for converting uranium tetrafluoride into hexafluoride has been developed successfully. To develop the process further, the construction of an integrated milling and conversion pilot plant (200 t-U/year) started in 1979 and was completed in 1981. This new plant has two systems of solvent extraction using tri-noctylamine: one of the systems treats the pregnant solution (uranyl sulphate) by heap-leaching followed by ion exchange, and the other treats the uranyl sulphate solution by dissolving imported yellowcake. The uranium loading solvents from the two systems are stripped with hydrochloric acid solution to obtain the concentrated uranium solution containing 100 g-U/1. Uranyl sulphate solution from the stripping circuit is reduced to a uranous sulphate solution by the electrolytic method. In a reduction cell, uranyl sulphate solution and dilute sulphuric acid are used respectively as catholyte and anolyte, and a cation exchange membrane is used to prevent re-oxidation of the uranous sulphate. In the following hydrofluorination step, uranium tetrafluoride, UF 4 .1-1.2H 2 O (particle size: 50-100μ), is produced continuously as the precipitate in an improved reaction vessel, and this makes it possible to simplify the procedures of liquid-solid separation, drying and granulation. The uranium tetrafluoride is dehydrated by heating to 350 0 C in an inert gas flow. The complete conversion from UF 4 into UF 6 is achieved by a fluidized-bed reactor and a high value of utilization efficiency of fluorine, over 99.9 percent, is attained at about 400 0 C. (author)

  14. Systems Engineering Model for ART Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Cruz, Carmen Margarita [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, Gary E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Mollye C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    The near-term objective of the EC team is to establish an operating, commercially scalable Recompression Closed Brayton Cycle (RCBC) to be constructed for the NE - STEP demonstration system (demo) with the lowest risk possible. A systems engineering approach is recommended to ensure adequate requirements gathering, documentation, and mode ling that supports technology development relevant to advanced reactors while supporting crosscut interests in potential applications. A holistic systems engineering model was designed for the ART Energy Conversion program by leveraging Concurrent Engineering, Balance Model, Simplified V Model, and Project Management principles. The resulting model supports the identification and validation of lifecycle Brayton systems requirements, and allows designers to detail system-specific components relevant to the current stage in the lifecycle, while maintaining a holistic view of all system elements.

  15. Nova frequency conversion and focusing system

    International Nuclear Information System (INIS)

    Summers, M.A.; Seppala, L.G.; Williams, J.D.

    1985-01-01

    New developments in crystal array technology provided significant improvements in the mechanical design and optical performance of the Nova 2 omega/3 omega array hardware. The final Nova array configuration was tested on the Novette laser and on the first arm of Nova. Ten Nova 2 omega/3 omega crystal arrays were assembled and tested for crystal alignment and wave front distortion before installation on the Nova target chamber. Ten Nova focus lens positioners were assembled and tested last year. The positioning accuracy and repeatability of each assembly were evaluated before installation on the target chamber. A cylindrical focusing system was also developed for installation in the Nova lens positioner assembly. Finally, 10 completed frequency conversion and focusing systems were activated

  16. Development of a high temperature solar receiver for high-efficient thermionic conversion systems; Fukugo netsuden henkan system yo chokoon taiyo junetsuki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Umeoka, T; Naito, H; Yugami, H; Arashi, H [Tohoku University, Sendai (Japan). Faculty of Engineering

    1996-10-27

    For thermionic conversion systems (TIC) using concentrated sunlight as heat source, the newly developed solar receiver was tested. Concentrated sunlight aims at the inner surface of the cavity type solar receiver. The emitter of TIC installed in the rear of the solar receiver is uniformly heated over 1700K by thermal radiation from the rear of the solar receiver, emitting thermion. Electric power is generated by collecting the thermion by collector. Mo is used as emitter material, however, because of poor heat absorption of Mo, high-absorptive TiC is used for heat absorption surface to heat Mo by thermal conduction from high-temperature TiC. Functionally gradient material (FGM) with an intermediate layer of gradient TiC/Mo ratios between TiC and Mo is used as emitter material. The emitter is thus uniformly heated at high temperatures of 1723{plus_minus}12K. As a result, the developed solar receiver is applicable to heat the emitter of TIC. Heat flux measurement at the graphite cavity clarified that cavity temperature of as high as 1780K and heat flow of 50W/cm{sup 2} are obtained at 4.7kW in input. 6 figs.

  17. Standard-Cell, Open-Architecture Power Conversion Systems

    National Research Council Canada - National Science Library

    Boroyevich, D; Wang, F; Lee, F. C; Odendaal, W. G; Edwards, S

    2005-01-01

    ...). This project was purposefully aimed to develop a standardized hierarchical design and analysis methodology for modular power electronics conversion systems using as basis the ISO/OSI seven-layer reference model...

  18. Development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, A. [Quebec Univ., Montreal, PQ (Canada). Dept. of Electrical Engineering

    2010-07-01

    Interest in renewable energy sources has grown in recent years in response to concerns of increasing pollution levels and depleting fossil fuels. Among renewable energy sources, wind energy generation is the fastest growing technology and one of the most cost-effective and environmental friendly means to generate electricity from renewable sources. Modern wind turbines are ready to be deployed in large scale as a result of recent developments in wind power technology. Variable speed permanent magnet synchronous generators (PMSG) based wind energy conversion systems (WECS) are becoming more popular. The use of a permanent magnet reduces size, cost and weight of overall WECS. In addition, the absence of field winding and its excitation system avoids heat dissipation in the rotor winding, thereby improving overall efficiency of the WECS. This type of configuration is more appropriate for remote locations, particularly for off-shore wind application, where the geared doubly fed induction generator usually requires regular maintenance due to tearing-wearing in brushes, windings and gear box. This presentation discussed the development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features. A novel adaptive network-based fuzzy inference system was used to estimate the speed and position of variable speed PMSG under fluctuating wind conditions. A novel control strategy was developed for the grid interfacing inverter incorporating power quality improvement features at point of common coupling.

  19. Relating Communications Mode Choice and Teamwork Quality: Conversational versus Textual Communication in IT System and Software Development Teams

    Science.gov (United States)

    Smith, James Robert

    2012-01-01

    This cross-sectional study explored how IT system and software development team members communicated in the workplace and whether teams that used more verbal communication (and less text-based communication) experienced higher levels of collaboration as measured using the Teamwork Quality (TWQ) scale. Although computer-mediated communication tools…

  20. Advanced energy conversion & mechatronics systems

    NARCIS (Netherlands)

    Lomonova, E.A.

    2015-01-01

    Ultra-high precision systems are encountered in high-tech industrial applications including semiconductor lithography equipment, pick-and-place machines for the manufacturing of electronic components, microsurgery equipment, MRI equipment and calibration devices in electron microscopes. The

  1. Sperry Low Temperature Geothermal Conversion System, Phase I and Phase II. Volume V. Component development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, C.; McBee, W.; Matthews, H.B.

    1984-01-01

    The fundamental inventions which motivate this program are system concepts centered on a novel heat engine cycle and the use of downwell heat exchange. Here, the primary emphasis is on downwell hardware. The only surface equipment included is the surface portion of the instrumentation and control systems. Downwell instrumentation is reported. Downwell conduits and techniques for installing, connecting and sealing them are covered. The downwell turbine-pump unit (TPU) is a critical component since it is relatively inaccessible and operates in a hostile environment. Its development is reported. The TPU for the gravity-head system requires a different type of turbine because of the large flow-rate through it and the small pressure difference across it. The design study for a Francis turbine to meet these requirements is reported. A feature of these systems is use of a downwell heat exchanger. There were extensive studies of tube-bundle configuration, tube-sheet seals, structural integrity, and flow and heat transfer, as well as the research on welded connections and sliding elastomeric seals. Another innovative component in these systems is the enthalpy recovery unit (ERU). This direct-contact heat exchanger compensates for under-cooling in the condenser and superheat in the main turbine exhaust.

  2. Advanced Radioisotope Power Conversion Technology Research and Development

    Science.gov (United States)

    Wong, Wayne A.

    2004-01-01

    NASA's Radioisotope Power Conversion Technology program is developing next generation power conversion technologies that will enable future missions that have requirements that cannot be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power System (RPS) technology. Performance goals of advanced radioisotope power systems include improvement over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. NASA has awarded ten contracts in the technology areas of Brayton, Stirling, Thermoelectric, and Thermophotovoltaic power conversion including five development contracts that deal with more mature technologies and five research contracts. The Advanced RPS Systems Assessment Team includes members from NASA GRC, JPL, DOE and Orbital Sciences whose function is to review the technologies being developed under the ten Radioisotope Power Conversion Technology contracts and assess their relevance to NASA's future missions. Presented is an overview of the ten radioisotope power conversion technology contracts and NASA's Advanced RPS Systems Assessment Team.

  3. Development of methane conversion improvement method by recycling of residual methane for steam reforming as a part of R and D of HTGR-hydrogen production system

    International Nuclear Information System (INIS)

    Inagaki, Yoshiyuki; Haga, Katsuhiro; Aita, Hideki; Sekita, Kenji; Hino, Ryutaro; Koiso, Hiroshi.

    1998-01-01

    The purpose of the present study is to improve methane conversion for an HTGR-steam reforming system by recycling of residual methane. The residual methane in a product gas after steam reforming was recycled with a gas separator of polyimide membrane. Gas separation characteristics of the separator were investigated experimentally and numerically, and an experimental study on recycling system was carried out. The results showed that the recycling system improves apparent methane conversion, ratio of methane conversion to methane supply from a cylinder, from 20 to 32% compared with those without recycling. (author)

  4. 24 CFR 972.109 - Conversion of developments.

    Science.gov (United States)

    2010-04-01

    ... writing whether it has approved the conversion plan. Units that are vacant or vacated on or after the... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Conversion of developments. 972.109... DEVELOPMENT CONVERSION OF PUBLIC HOUSING TO TENANT-BASED ASSISTANCE Required Conversion of Public Housing...

  5. TFTR power conversion and plasma feedback systems

    International Nuclear Information System (INIS)

    Neumeyer, C.

    1985-01-01

    Major components of the Tokamak Fusion Test Reactor (TFTR) power conversion system include 39 thyristor rectifier power supplies, 12 energy storage capacitor banks, and 6 ohmic heating interrupters. These components are connected in various series/parallel configurations to provide controlled pulses of current to the Toroidal Field (TF), Ohmic Heating (OH), Equilibrium (vertical) Field (EF), and Horizontal Field (HF) magnet coil systems. Real-time control of the power conversion system is accomplished by a centralized dedicated computer; local control is minimal. Power supply firing angles, capacitor bank charge and discharge commands, interrupter commands, etc., are all determined and issued by the central computer. Plasma Position and Current Control (PPCC) reference signals to power conversion (OH, EF, HF) are determined by separate analog electronics but invoked through the power conversion computer. Real-time fault sensing of plasma parameters, gas injection, neutral beams, etc., are monitored by a separate Discharge Fault System (DFS) but routed through the power conversion computer for pre-programmed shutdown response

  6. A System for Electromagnetic Field Conversion

    DEFF Research Database (Denmark)

    2003-01-01

    A system is provided for conversion of a first electromagnetic field into a desired second electromagnetic field, for example for coupling modes between waveguides or into microstructured waveguides. The system comprises a complex spatial electromagnetic field converter that is positioned...... for reception of at least a part of the first electromagnetic field and that is adapted for conversion of the received field into the desired electromagnetic field, and wherein at least one of the first and second fields matches a mode of a microstructured waveguide. It is an important advantage of the present...

  7. Optical Energy Transfer and Conversion System

    Science.gov (United States)

    Hogan, Bartholomew P. (Inventor); Stone, William C. (Inventor)

    2018-01-01

    An optical energy transfer and conversion system comprising a fiber spooler and an electrical power extraction subsystem connected to the spooler with an optical waveguide. Optical energy is generated at and transferred from a base station through fiber wrapped around the spooler, and ultimately to the power extraction system at a remote mobility platform for conversion to another form of energy. The fiber spooler may reside on the remote mobility platform which may be a vehicle, or apparatus that is either self-propelled or is carried by a secondary mobility platform either on land, under the sea, in the air or in space.

  8. Synchronous generator wind energy conversion control system

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  9. Systems and methods for wave energy conversion

    Science.gov (United States)

    MacDonald, Daniel G.; Cantara, Justin; Nathan, Craig; Lopes, Amy M.; Green, Brandon E.

    2017-02-28

    Systems for wave energy conversion that have components that can survive the harsh marine environment and that can be attached to fixed structures, such as a pier, and having the ability to naturally adjust for tidal height and methods for their use are presented.

  10. Light distribution system comprising spectral conversion means

    DEFF Research Database (Denmark)

    2012-01-01

    , longer wavelength,a spectral conversion characteristics of the spectral conversion fibre being essentially determined by the spectral absorption and emission properties of the photoluminescent agent, the amount of photo- luminescent agent,and the distribution of the photoluminescent agent in the spectral......System (200, 300) for the distribution of white light, having a supply side (201, 301, 401) and a delivery side (202, 302, 402), the system being configured for guiding light with a multitude of visible wavelengths in a propagation direction P from the supply side to the distribution side...... of providing a light distribution system and a method of correcting the spectral transmission characteristics of a light distribution system are disclosed....

  11. Ocean thermal energy conversion (OTEC) power system development (PSD) II. Preliminary design report. Appendix II: supporting data

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-10

    The trade studies, calculations, and reports which provide the rationale for design conclusions for the 10 MWe OTEC power system are presented in this volume. These appendices include: (1) system design and optimization model; (2) system off-design performance computer model; (3) seawater system dynamics; (4) system mechanical design studies; (5) electrical design studies; (6) structural design studies; (7) tube cleaner design report and proposed brush test program; (8) heat exchangers: mechanical design; (9) heat exchangers: thermal hydraulic computer model; (10) heat exchangers: manufacturing flow plan; (11) heat exchangers: installation and removal procedures; (12) heat exchangers: stainless steel conceptual design; (13) heat exchangers: cost studies; (14)heat exchangers: materials selection and corrosion; and (15) heat exchangers: quality assurance. (WHK)

  12. The Conversion of Wiswesser Line Notations to Ring Codes. I. The Conversion of Ring Systems

    Science.gov (United States)

    Granito, Charles E.; And Others

    1972-01-01

    The computerized conversion of Wiswesser Line Notations to Ring Codes, using a two-part approach, and the set of computer programs generated for the conversion of ring systems are described. (9 references) (Author)

  13. CO2 utilization: Developments in conversion processes

    Directory of Open Access Journals (Sweden)

    Erdogan Alper

    2017-03-01

    The potential utilization of CO2, captured at power plants, should also been taken into consideration for sustainability. This CO2 source, which is potentially a raw material for the chemical industry, will be available at sufficient quality and at gigantic quantity upon realization of on-going tangible capture projects. Products resulting from carboxylation reactions are obvious conversions. In addition, provided that enough supply of energy from non-fossil resources, such as solar [1], is ensured, CO2 reduction reactions can produce several valuable commodity chemicals including multi-carbon compounds, such as ethylene and acrylic acid, in addition to C1 chemicals and polymers. Presently, there are only few developing technologies which can find industrial applications. Therefore, there is a need for concerted research in order to assess the viability of these promising exploratory technologies rationally.

  14. Energy technology sources, systems and frontier conversion

    CERN Document Server

    Ohta, Tokio

    1994-01-01

    This book provides a concise and technical overview of energy technology: the sources of energy, energy systems and frontier conversion. As well as serving as a basic reference book for professional scientists and students of energy, it is intended for scientists and policy makers in other disciplines (including practising engineers, biologists, physicists, economists and managers in energy related industries) who need an up-to-date and authoritative guide to the field of energy technology.Energy systems and their elemental technologies are introduced and evaluated from the view point

  15. Recent Progress on Integrated Energy Conversion and Storage Systems.

    Science.gov (United States)

    Luo, Bin; Ye, Delai; Wang, Lianzhou

    2017-09-01

    Over the last few decades, there has been increasing interest in the design and construction of integrated energy conversion and storage systems (IECSSs) that can simultaneously capture and store various forms of energies from nature. A large number of IECSSs have been developed with different combination of energy conversion technologies such as solar cells, mechanical generators and thermoelectric generators and energy storage devices such as rechargeable batteries and supercapacitors. This review summarizes the recent advancements to date of IECSSs based on different energy sources including solar, mechanical, thermal as well as multiple types of energies, with a special focus on the system configuration and working mechanism. With the rapid development of new energy conversion and storage technologies, innovative high performance IECSSs are of high expectation to be realised for diverse practical applications in the near future.

  16. WIND ENERGY CONVERSION SYSTEMS - A TECHNICAL REVIEW

    Directory of Open Access Journals (Sweden)

    N. RAMESH BABU

    2013-08-01

    Full Text Available Wind power production has been under the main focus for the past decade in power production and tremendous amount of research work is going on renewable energy, specifically on wind power extraction. Wind power provides an eco-friendly power generation and helps to meet the national energy demand when there is a diminishing trend in terms of non-renewable resources. This paper reviews the modeling of Wind Energy Conversion Systems (WECS, control strategies of controllers and various Maximum Power Point Tracking (MPPT technologies that are being proposed for efficient production of wind energy from the available resource.

  17. Thermoelectric Energy Conversion: Materials, Devices, and Systems

    International Nuclear Information System (INIS)

    Chen, Gang

    2015-01-01

    This paper will present a discussion of challenges, progresses, and opportunities in thermoelectric energy conversion technology. We will start with an introduction to thermoelectric technology, followed by discussing advances in thermoelectric materials, devices, and systems. Thermoelectric energy conversion exploits the Seebeck effect to convert thermal energy into electricity, or the Peltier effect for heat pumping applications. Thermoelectric devices are scalable, capable of generating power from nano Watts to mega Watts. One key issue is to improve materials thermoelectric figure- of-merit that is linearly proportional to the Seebeck coefficient, the square of the electrical conductivity, and inversely proportional to the thermal conductivity. Improving the figure-of-merit requires good understanding of electron and phonon transport as their properties are often contradictory in trends. Over the past decade, excellent progresses have been made in the understanding of electron and phonon transport in thermoelectric materials, and in improving existing and identify new materials, especially by exploring nanoscale size effects. Taking materials to real world applications, however, faces more challenges in terms of materials stability, device fabrication, thermal management and system design. Progresses and lessons learnt from our effort in fabricating thermoelectric devices will be discussed. We have demonstrated device thermal-to-electrical energy conversion efficiency ∼10% and solar-thermoelectric generator efficiency at 4.6% without optical concentration of sunlight (Figure 1) and ∼8-9% efficiency with optical concentration. Great opportunities exist in advancing materials as well as in using existing materials for energy efficiency improvements and renewable energy utilization, as well as mobile applications. (paper)

  18. Modeling on a PWR power conversion system with system program

    International Nuclear Information System (INIS)

    Gao Rui; Yang Yanhua; Lin Meng

    2007-01-01

    Based on the power conversion system of nuclear and conventional islands of Daya Bay Power Station, this paper models the thermal-hydraulic systems of primary and secondary loops for PWR by using the PWR best-estimate program-RELAP5. To simulate the full-scope power conversion system, not only the traditional basic system models of nuclear island, but also the major system models of conventional island are all considered and modeled. A comparison between the calculated results and the actual data of reactor demonstrates a fine match for Daya Bay Nuclear Power Station, and manifests the feasibility in simulating full-scope power conversion system of PWR by RELAP5 at the same time. (authors)

  19. Advanced materials and coatings for energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    St Pierre, George R. [Ohio State Univ., Materials Science and Engineering Dept., Columbus, OH (United States)

    1997-12-31

    Following an historical review of the development of high-temperature alloys for energy conversion systems including turbine engines, some of the current advances in single crystal materials, intermetallics, metal-matrix composites, and ceramic-matrix composites are discussed. Particular attention is directed at creep phenomena, fatigue properties and oxidation resistance. Included within the discussions is the current status of carbon/carbon composites as potential high-temperature engineering materials and the development of coating systems for thermal barrier and oxidation protection. The specific influences of combustion gas compositions, i.e., oxidation potential, sulfur, halides, etc. are discussed. A current list of eligible advanced materials and coatings systems is presented and assessed. Finally, the critical failure mechanism and life-prediction parameters for some of the new classes of advanced structural materials are elaborated with the view to achieving affordability and extended life with a high degree of reliability. Examples are drawn from a variety of energy conversion systems. (Author)

  20. Inertial confinement fusion reaction chamber and power conversion system study

    International Nuclear Information System (INIS)

    Maya, I.; Schultz, K.R.; Battaglia, J.M.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li 2 O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li 2 O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li 2 O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive

  1. Electrical Systems for Wave Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Bostroem, Cecilia

    2011-07-01

    Wave energy is a renewable energy source with a large potential to contribute to the world's electricity production. There exist several technologies on how to convert the energy in the ocean waves into electric energy. The wave energy converter (WEC) presented in this thesis is based on a linear synchronous generator. The generator is placed on the seabed and driven by a point absorbing buoy on the ocean surface. Instead of having one large unit, several smaller units are interconnected to increase the total installed power. To convert and interconnect the power from the generators, marine substations are used. The marine substations are placed on the seabed and convert the fluctuating AC from the generators into an AC suitable for grid connection. The work presented in the thesis focuses on the first steps in the electric energy conversion, converting the voltage out from the generators into DC, which have an impact on the WEC's ability to absorb and produce power. The purpose has been to investigate how the generator will operate when it is subjected to different load cases and to obtain guidelines on how future systems could be improved. Offshore experiments and simulations have been done on full scale generators connected to four different loads, i.e. one linear resistive load and three different non-linear loads representing different cases for grid connected WECs. The results show that the power can be controlled and optimized by choosing a suitable system for the WEC. It is not obvious which kind of system is the most preferable, since there are many different parameters that have an impact on the system performance, such as the size of the buoy, how the generator is designed, the number of WECs, the highest allowed complexity of the system, costs and so on. Therefore, the design of the electrical system should preferably be carried out in parallel with the design of the WEC in order to achieve an efficient system

  2. Technology assessment of wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Meier, B. W.; Merson, T. J.

    1980-09-01

    Environmental data for wind energy conversion systems (WECSs) have been generated in support of the Technology Assessment of Solar Energy (TASE) program. Two candidates have been chosen to characterize the WECS that might be deployed if this technology makes a significant contribution to the national energy requirements. One WECS is a large machine of 1.5-MW-rated capacity that can be used by utilities. The other WECS is a small machine that is characteristic of units that might be used to meet residential or small business energy requirements. Energy storage systems are discussed for each machine to address the intermittent nature of wind power. Many types of WECSs are being studied and a brief review of the technology is included to give background for choosing horizontal axis designs for this study. Cost estimates have been made for both large and small systems as required for input to the Strategic Environmental Assessment Simulation (SEAS) computer program. Material requirements, based on current generation WECSs, are discussed and a general discussion of environmental impacts associated with WECS deployment is presented.

  3. Adaptability of solar energy conversion systems on ships

    Science.gov (United States)

    Visa, I.; Cotorcea, A.; Neagoe, M.; Moldovan, M.

    2016-08-01

    International trade of goods largely uses maritime/transoceanic ships driven by engines using fossil fuels. This two centuries tradition is technologically mature but significantly adds to the CO2 emissions; therefore, recent trends focus on on-board implementation of systems converting the solar energy into power (photovoltaic systems) or heat (solar-thermal systems). These systems are carbon-emissions free but are still under research and plenty of effort is devoted to fast reach maturity and feasibility. Unlike the systems implemented in a specific continental location, the design of solar energy conversion systems installed on shipboard has to face the problem generated by the system base motion along with the ship travelling on routes at different latitudes: the navigation direction and sense and roll-pitch combined motion with reduced amplitude, but with relatively high frequency. These raise highly interesting challenges in the design and development of mechanical systems that support the maximal output in terms of electricity or heat. The paper addresses the modelling of the relative position of a solar energy conversion surface installed on a ship according to the current position of the sun; the model is based on the navigation trajectory/route, ship motion generated by waves and the relative sun-earth motion. The model describes the incidence angle of the sunray on the conversion surface through five characteristic angles: three used to define the ship orientation and two for the solar angles; based on, their influence on the efficiency in solar energy collection is analyzed by numerical simulations and appropriate recommendations are formulated for increasing the solar energy conversion systems adaptability on ships.

  4. Supercritical Carbon Dioxide Brayton Cycle Energy Conversion System

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jae Eun; Kim, S. O.; Seong, S. H.; Eoh, J. H.; Lee, T. H.; Choi, S. K.; Han, J. W.; Bae, S. W

    2007-12-15

    This report contains the description of the S-CO{sub 2} Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system. For system development, a computer code was developed to calculate heat balance of 100% power operation condition. Based on the computer code, the S-CO{sub 2} Brayton cycle energy conversion system was constructed for the KALIMER-600. Using the developed turbomachinery models, the off-design characteristics and the sensitivities of the S-CO{sub 2} turbomachinery were investigated. For the development of PCHE models, a one-dimensional analysis computer code was developed to evaluate the performance of the PCHE. Possible control schemes for power control in the KALIMER-600 S-CO{sub 2} Brayton cycle were investigated by using the MARS code. Simple power reduction and recovery event was selected and analyzed for the transient calculation. For the evaluation of Na/CO{sub 2} boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO{sub 2} gas. The long term behavior of a Na/CO{sub 2} boundary failure event and its consequences which lead to a system pressure transient were evaluated.

  5. Supercritical Carbon Dioxide Brayton Cycle Energy Conversion System

    International Nuclear Information System (INIS)

    Cha, Jae Eun; Kim, S. O.; Seong, S. H.; Eoh, J. H.; Lee, T. H.; Choi, S. K.; Han, J. W.; Bae, S. W.

    2007-12-01

    This report contains the description of the S-CO 2 Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system. For system development, a computer code was developed to calculate heat balance of 100% power operation condition. Based on the computer code, the S-CO 2 Brayton cycle energy conversion system was constructed for the KALIMER-600. Using the developed turbomachinery models, the off-design characteristics and the sensitivities of the S-CO 2 turbomachinery were investigated. For the development of PCHE models, a one-dimensional analysis computer code was developed to evaluate the performance of the PCHE. Possible control schemes for power control in the KALIMER-600 S-CO 2 Brayton cycle were investigated by using the MARS code. Simple power reduction and recovery event was selected and analyzed for the transient calculation. For the evaluation of Na/CO 2 boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO 2 gas. The long term behavior of a Na/CO 2 boundary failure event and its consequences which lead to a system pressure transient were evaluated

  6. Revisit ocean thermal energy conversion system

    International Nuclear Information System (INIS)

    Huang, J.C.; Krock, H.J.; Oney, S.K.

    2003-01-01

    The earth, covered more than 70.8% by the ocean, receives most of its energy from the sun. Solar energy is transmitted through the atmosphere and efficiently collected and stored in the surface layer of the ocean, largely in the tropical zone. Some of the energy is re-emitted to the atmosphere to drive the hydrologic cycle and wind. The wind field returns some of the energy to the ocean in the form of waves and currents. The majority of the absorbed solar energy is stored in vertical thermal gradients near the surface layer of the ocean, most of which is in the tropical region. This thermal energy replenished each day by the sun in the tropical ocean represents a tremendous pollution-free energy resource for human civilization. Ocean Thermal Energy Conversion (OTEC) technology refers to a mechanical system that utilizes the natural temperature gradient that exists in the tropical ocean between the warm surface water and the deep cold water, to generate electricity and produce other economically valuable by-products. The science and engineering behind OTEC have been studied in the US since the mid-seventies, supported early by the U.S. Government and later by State and private industries. There are two general types of OTEC designs: closed-cycle plants utilize the evaporation of a working fluid, such as ammonia or propylene, to drive the turbine-generator, and open-cycle plants use steam from evaporated sea water to run the turbine. Another commonly known design, hybrid plants, is a combination of the two. OTEC requires relatively low operation and maintenance costs and no fossil fuel consumption. OTEC system possesses a formidable potential capacity for renewable energy and offers a significant elimination of greenhouse gases in producing power. In addition to electricity and drinking water, an OTEC system can produce many valuable by-products and side-utilizations, such as: hydrogen, air-conditioning, ice, aquaculture, and agriculture, etc. The potential of these

  7. Care and Conversing in Dialogical Systems

    DEFF Research Database (Denmark)

    Steffensen, Sune Vork

    2012-01-01

    positions, a theory of dialogical systems is developed, on the basis of current thinking within the enactive program (e.g. De Jaegher and Di Paolo, 2007), the distributed language movement (e.g. Cowley, 2011b), and values-realizing theory (e.g. Hodges, 2009). Dialogical systems are systems of co......This article promotes a point of view on human interaction in terms of dialogical systems. The approach draws on recent, so-called third wave, developments in cognitive science. After an introduction to three waves in cognitive science, and their counterparts in linguistics, the article is placed......-present human beings engaged in interactivity that bring forth situated behavioural coordination (or a communicative, structural coupling). Dialogical systems, however, have emergent properties irreducible to individual actions or microsocial norms. Among the emergent properties one find a tendency to establish...

  8. Conversion developments in Alatau joint stock company

    International Nuclear Information System (INIS)

    Zyuzko, A.

    1996-01-01

    To solve this situation it is necessary to organize manufacturing of marketable products at the enterprise but implementation of this goal requires investments allocations. In the frames of international cooperation we submit the following three projects: o modernization of construction and development of new modifications of electric stimulator of alimentary canal; o development and bringing into production of GSA-1 welding-gas generator installation; o development and bringing to a commercial level production of thermal elements for refrigerator devices, production of consumer's cooling devices; 1. Electric stimulator of alimentary canal (ESAC) is a medical a new level micro equipment, it was awarded diploma and medals of international exhibitions, including Medicine-92. ESAC is designed for electronic pulse stimulation of alimentary canal to restore its motor-evacuation activity. ESAC is the first among new devices which allows to make effective correction and activation of a number of degrading systems of human body without medicines, injures, a patient may stay at home and himself determine necessity of ESAC usage. 2. GSA-1 welding - gas generator installation uses ecologically safe power supply, that is hydrogen-oxygen produced by water electrolysing by caustic natrium or Potassium what excludes usage of calcium carbide and technical oxygen in gas-bags. The installation operates at 220 V voltage, frequency of 50 cycles/second, power supply 4 kw, its size is 865 sub x sub 728, weight - 75 kg. GSA-1 is designated for welding, cutting, soldering of steel and non-ferrous metals of the width to 4 mim. 3. Mastering of production of freon-free refrigerator installations based on thermoelectric transformers. The objective of the project is to master production and to manufacture consumers thermoelectric refrigerator-devices, conditioners, automobile bags-refrigerators. The main element vices, conditioners, automobile bags-refrigerators. The main element of all these

  9. The Energy Conversion Analysis of HTR Gas Turbine System

    International Nuclear Information System (INIS)

    Utaja

    2000-01-01

    The energy conversion analysis of HTR gas turbine system by hand calculation is tedious work and need much time. This difficulty comes from the repeated thermodynamic process calculation, both on compression or expansion of the cycle. To make the analysis faster and wider variable analyzed, HTR-1 programme is used. In this paper, the energy conversion analysis of HTR gas turbine system by HTR-1 will be described. The result is displayed as efficiency curve and block diagram with the input and output temperature of the component. This HTR-1 programme is developed by Basic language programming and be compiled by Visual Basic 5.0 . By this HTR-1 programme, the efficiency, specific power and effective compression of the amount of gas can be recognized fast. For example, for CO 2 gas between 40 o C and 700 o C, the compression on maximum efficiency is 4.6 and the energy specific is 18.9 kcal/kg, while the temperature changing on input and output of the component can be traced on monitor. This process take less than one second, while the manual calculation take more than one hour. It can be concluded, that the energy conversion analysis of the HTR gas turbine system by HTR-1 can be done faster and more variable analyzed. (author)

  10. Lab-scale development of a high temperature aerosol particle sampling probe system for field measurements in thermochemical conversion of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Lindskog, M.; Malik, A.; Pagels, J.; Sanati, M. [Lund Univ., Lund (Sweden). Div. of Ergonomics and Aerosol Technology

    2010-07-01

    Thermochemical conversion of biomass requires both combustion in an oxygen rich environment and gasification in an oxygen deficient environment. Therefore, the mass concentration of fly ash from combustion processes is dominated by inorganic compounds, and the particulate matter obtained from gasification is dominated by carbonaceous compounds. The fine fly ash particles can initiate corrosion and fouling and also increases emissions of fine particulates to the atmosphere. This study involved the design of a laboratory scale setup consisting of a high temperature sampling probe and an aerosol generation system to study the formation of fine particle from biomass gasification processes. An aerosol model system using potassium chloride (KCl) as the ash compound and Di Octyl Sebacate oil (DOS) as the volatile organic part was used to test the high temperature sampling probe. Tests conducted at 200 degrees C showed good reproducibility of the aerosol generator. The tests also demonstrated suitable dilution ratios which enabled the denuder to absorb all of the gaseous organic compounds in the set up, thus enabling measurement of only the particle phase. Condensable organic concentrations of 1-68 mg/m{sup 3} were easily handled by the high temperature sampling probe system, indicating that the denuder worked well. Additional tests will be performed using an Aerosol Mass Spectrometer (AMST) to verify that the denuder can capture all of the gaseous organic compounds also when condensed onto agglomerated soot particles. 6 refs., 1 tab., 9 figs.

  11. Carbon balances during land conversion in early bioenergy systems

    Science.gov (United States)

    Zenone, T.; Chen, J.; Gelfand, I.; Robertson, G. P.; Hamilton, S. K.

    2012-12-01

    In this study, we established a field experiment and deployed seven eddy-covariance towers to quantify the roles of land use change and the subsequent carbon (C) balances of three different bioenergy systems (corn, switchgrass, and mixed prairie species) that were developed from two historical land use types: monocultural grasslands dominated by smooth brome (Bromus inermis Leyss) and lands in the Conservation Reserve Program (CRP). Three CRP fields and three cropland fields were converted to soybean in 2009 (conversion year) before establishing the cellulosic biofuel cropping systems in 2010 (establishment year). A CRP perennial grassland site was kept undisturbed as a reference. Conversion of CRP to soybean induced net C emissions during the conversion year (134 -262 g C m-2 yr-1), while in the same year the net C balance at the CRP grassland reference was -35 g C m-2 yr-1 (i.e., net C sequestration). The establishment of switchgrass and mixed prairie induced a cumulative C balance of -113 g C m-2 (switchgrass from CRP), 250 g C m-2 (switchgrass from cropland), 706 g C m-2 (mixed prairie from CRP), and 59 g C m-2 (mixed prairie from cropland) over the three-year study period. The cumulative three-year C balance of corn converted from CRP and from cropland was -151 g C m-2 and -183 g C m-2, respectively. Eddy flux measurements during cellulosic biofuel crop establishment reveal annual changes in C balance that cannot be detected using conventional mass balance approaches. When end-use of harvested biomass was considered, the C balances for all studied systems, except the reference site, exhibited large C emissions ranging from 150 to 990 g C m-2 over the three-year conversion phase.

  12. Summary of State-of-the-Art Power Conversion Systems for Energy Storage Applications

    Energy Technology Data Exchange (ETDEWEB)

    Atcitty, S.; Gray-Fenner, A.; Ranade, S.

    1998-09-01

    The power conversion system (PCS) is a vital part of many energy storage systems. It serves as the interface between the storage device, an energy source, and an AC load. This report summarizes the results of an extensive study of state-of-the-art power conversion systems used for energy storage applications. The purpose of the study was to investigate the potential for cost reduction and performance improvement in these power conversion systems and to provide recommendations for fiture research and development. This report provides an overview of PCS technology, a description of several state-of-the-art power conversion systems and how they are used in specific applications, a summary of four basic configurations for l:he power conversion systems used in energy storage applications, a discussion of PCS costs and potential cost reductions, a summary of the stancku-ds and codes relevant to the technology, and recommendations for future research and development.

  13. Overview of SOFC/SOEC development at DTU Energy Conversion

    DEFF Research Database (Denmark)

    Hagen, Anke

    2014-01-01

    According to a broad political agreement in Denmark, the Danish energy system should become independent on fossil fuels like oil, coal and natural gas by the year 2050. This aim requires expansion of electricity production from renewable sources, in particular wind mills. In order to balance...... the fluctuating power production and to cope with the discrepancies between demand and supply of power, solid oxide fuel cells and electrolysis are considered key technologies. DTU Energy Conversion has a strong record in SOFC/SOEC research, with a close collaboration with industry, in particular with Danish...... Topsoe Fuel Cell A/S. Recent achievements will be presented ranging from development of new cell generations, manufacturability, up to testing under realistic operating conditions including degradation studies and high pressure testing. A strong focus will be on development of methodologies, e...

  14. Memory for conversation and the development of common ground.

    Science.gov (United States)

    McKinley, Geoffrey L; Brown-Schmidt, Sarah; Benjamin, Aaron S

    2017-11-01

    Efficient conversation is guided by the mutual knowledge, or common ground, that interlocutors form as a conversation progresses. Characterized from the perspective of commonly used measures of memory, efficient conversation should be closely associated with item memory-what was said-and context memory-who said what to whom. However, few studies have explicitly probed memory to evaluate what type of information is maintained following a communicative exchange. The current study examined how item and context memory relate to the development of common ground over the course of a conversation, and how these forms of memory vary as a function of one's role in a conversation as speaker or listener. The process of developing common ground was positively related to both item and context memory. In addition, content that was spoken was remembered better than content that was heard. Our findings illustrate how memory assessments can complement language measures by revealing the impact that basic conversational processes have on memory for what has been discussed. By taking this approach, we show that not only does the process of forming common ground facilitate communication in the present, but it also promotes an enduring record of that event, facilitating conversation into the future.

  15. The HOR core conversion program development and licensing experiences

    International Nuclear Information System (INIS)

    Vries, J.W. de; Gibcus, H.P.M.; Leege, P.F.A. de

    1997-01-01

    This paper deals with the experiences in the development of a fuel conversion program for a 2 MW university type research reactor, the HOR. It gives an overview of the technical and administrative aspects concerning the fuel conversion program development since the eighties, including the safety review and licensing process. The overall final safety report was submitted in 1995, together with the environmental impact report, and a licence application was submitted accordingly. The licence permitting the conversion was issued in 1996, coming into force at the beginning of this year, although an appeal case is still pending. At the moment the necessary preparations for starting the actual conversion of the HOR are made. The general program characteristics are addressed. (author)

  16. Process development for scum to biodiesel conversion.

    Science.gov (United States)

    Bi, Chong-hao; Min, Min; Nie, Yong; Xie, Qing-long; Lu, Qian; Deng, Xiang-yuan; Anderson, Erik; Li, Dong; Chen, Paul; Ruan, Roger

    2015-06-01

    A novel process was developed for converting scum, a waste material from wastewater treatment facilities, to biodiesel. Scum is an oily waste that was skimmed from the surface of primary and secondary settling tanks in wastewater treatment plants. Currently scum is treated either by anaerobic digestion or landfilling which raised several environmental issues. The newly developed process used a six-step method to convert scum to biodiesel, a higher value product. A combination of acid washing and acid catalyzed esterification was developed to remove soap and impurities while converting free fatty acids to methyl esters. A glycerol washing was used to facilitate the separation of biodiesel and glycerin after base catalyzed transesterification. As a result, 70% of dried and filtered scum was converted to biodiesel which is equivalent to about 134,000 gallon biodiesel per year for the Saint Paul waste water treatment plant in Minnesota. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Renewable energy systems advanced conversion technologies and applications

    CERN Document Server

    Luo, Fang Lin

    2012-01-01

    Energy conversion techniques are key in power electronics and even more so in renewable energy source systems, which require a large number of converters. Renewable Energy Systems: Advanced Conversion Technologies and Applications describes advanced conversion technologies and provides design examples of converters and inverters for renewable energy systems-including wind turbine and solar panel energy systems. Learn Cutting-Edge Techniques for Converters and Inverters Setting the scene, the book begins with a review of the basics of astronomy and Earth physics. It then systematically introduc

  18. Environmental Development Plan: uranium mining, milling, and conversion

    International Nuclear Information System (INIS)

    1979-08-01

    This Environmental Development Plan (EDP) identifies the planning and management requirements and schedules needed to evaluate and assess the environmental, health, and safety (EH and S) aspects of the uranium mining, milling, and conversion technologies. The plan represents the collective perceptions of EH and S concerns and requirements and knowledge of ongoing research programs of most of the Federal agencies involved in significant EH and S R and D program management, standards setting, or regulatory activities associated with uranium mining, milling, and conversion

  19. Development and Analysis of a Novel Multi-Mode MPPT Technique with Fast and Efficient Performance for PMSG-Based Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    S. Heshmatian

    2018-03-01

    Full Text Available Wind energy is one of the most promising renewable energy resources. Due to instantaneous variations of the wind speed, an appropriate Maximum Power Point Tracking (MPPT method is necessary for maximizing the captured energy from the wind at different speeds. The most commonly used MPPT algorithms are Tip Speed Ratio (TSR, Power Signal Feedback (PSF, Optimal Torque Control (OTC and Hill Climbing Search (HCS. Each of these algorithms has some advantages and also some major drawbacks. In this paper, a novel hybrid MPPT algorithm is proposed which modifies the conventional methods in a way that eliminates their drawbacks and yields an improved performance. This proposed algorithm is faster in tracking the maximum power point and provides a more accurate response with lower steady state error. Moreover, it presents a great performance under conditions with intensive wind speed variations. The studied Wind Energy Conversion System (WECS consists of a Permanent Magnet Synchronous Generator (PMSG connected to the dc link through a Pulse-Width Modulated (PWM rectifier. The proposed algorithm and the conventional methods are applied to this WECS and their performances are compared using the simulation results. These results approve the satisfactory performance of the proposed algorithm and its notable advantages over the conventional methods.

  20. ASTRID power conversion system: Assessment on steam and gas options

    International Nuclear Information System (INIS)

    Laffont, Guy; Cachon, Lionel; Jourdain, Vincent; Fauque, Jean Marie

    2013-01-01

    Conclusion: ◆ Two power conversion systems have been investigated for the ASTRID prototype. ◆ Steam PCS: • Most mature system based on a well-developed turbomachinery technology. • High plant efficiency. • Studies on steam generators designs and leak detection systems in progress with the aim of reducing the risk of large SWRs and of limiting its consequences. • Design and licensing safety assessment of a SFR must deal with the Sodium Water Air reaction (SWAR). ◆ Gas PCS: • Strong advantage as it inherently eliminates the SWR and SWAR risks. • Very innovative option: major breakthroughs but feasibility and viability not yet demonstrated. • Remaining technological challenges but no showstopper indentified. • General architecture: investigations in progress to improve performances, operability and maintainability

  1. Mirror hybrid reactor blanket and power conversion system conceptual design

    International Nuclear Information System (INIS)

    Schultz, K.R.; Backus, G.A.; Baxi, C.B.; Dee, J.B.; Estrine, E.A.; Rao, R.; Veca, A.R.

    1976-01-01

    The conceptual design of the blanket and power conversion system for a gas-cooled mirror hybrid fusion-fission reactor is presented. The designs of the fuel, blanket module and power conversion system are based on existing gas-cooled fission reactor technology that has been developed at General Atomic Company. The uranium silicide fuel is contained in Inconel-clad rods and is cooled by helium gas. The fuel is contained in 16 spherical segment modules which surround the fusion plasma. The hot helium is used to raise steam for a conventional steam cycle turbine generator. The details of the method of support for the massive blanket modules and helium ducts remain to be determined. Nevertheless, the conceptual design appears to be technically feasible with existing gas-cooled technology. A preliminary safety analysis shows that with the development of a satisfactory method of primary coolant circuit containment and support, the hybrid reactor could be licensed under existing Nuclear Regulatory Commission regulations

  2. Developing multimodal conversational agents for an enhanced e-learning experience

    Directory of Open Access Journals (Sweden)

    David GRIOL

    2014-10-01

    Full Text Available Conversational agents have become a strong alternative to enhance educational systems with intelligent communicative capabilities, provide motivation and engagement, and increment significant learning and helping in the acquisition of meta-cognitive skills. In this paper, we present Geranium, a multimodal conversational agent that helps children to appreciate and protect their environment. The system, which integrates an interactive chatbot, has been developed by means of a modular and scalable framework that eases building pedagogic conversational agents that can interact with the students using speech and natural language.

  3. Ocean Thermal Energy Conversion power system development. Phase I: preliminary design. Final report. [ODSP-3 code; OTEC Steady-State Analysis Program

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The following appendices are included; Dynamic Simulation Program (ODSP-3); sample results of dynamic simulation; trip report - NH/sub 3/ safety precautions/accident records; trip report - US Coast Guard Headquarters; OTEC power system development, preliminary design test program report; medium turbine generator inspection point program; net energy analysis; bus bar cost of electricity; OTEC technical specifications; and engineer drawings. (WHK)

  4. Social conversational skills development in early implanted children.

    Science.gov (United States)

    Guerzoni, Letizia; Murri, Alessandra; Fabrizi, Enrico; Nicastri, Maria; Mancini, Patrizia; Cuda, Domenico

    2016-09-01

    Social conversational skills are a salient aspect of early pragmatic development in young children. These skills include two different abilities, assertiveness and responsiveness. This study investigated the development of these abilities in early implanted children and their relationships with lexical development and some language-sensitive variables. Prospective, observational, nonrandomized study. Participants included 28 children with congenital profound sensorineural hearing loss. The mean age at device activation was 13.3 months (standard deviation [SD] ±4.2). The Social-Conversational Skills Rating Scale was used to evaluate assertiveness and responsiveness. The MacArthur-Bates Communicative Development Inventory (Words and Sentences form) was used to analyze the lexical development. The device experience was 12 months for each child, and the mean age at testing was 25.9 months (SD ±4.6). Assertiveness and responsiveness scores were within the normal range of normal-hearing age-matched peers. Age at cochlear implant activation exerted a significant impact, with the highest scores associated to the youngest patients. The residual correlations between assertiveness and responsiveness with the lexical development were positive and strongly significant (r = 0.69 and 0.73, respectively). Preoperative hearing threshold demonstrated an associated significant coefficient on the assertiveness score. Age at diagnosis and maternal education level were not correlated with the social conversational skills. Early-implanted children developed social conversational skills that are similar to normal-hearing peers matched for age 1 year after device activation. Social conversational skills and lexical development were strongly correlated, but the present study design cannot specify the direction of this relationship. Children with better preoperative residual hearing exhibited better assertive ability. 4 Laryngoscope, 126:2098-2105, 2016. © 2015 The American Laryngological

  5. Status of LEU fuel development and conversion of NRU

    International Nuclear Information System (INIS)

    Sears, D.F.; Herbert, L.N.; Vaillancourt, K.D.

    1991-01-01

    This paper reviews the status of the LEU conversion program and the progress made in the fuel development program over the last year. The results from post-irradiation examinations of prototype NRU fuel rods containing Al-U 3 Si dispersion fuel, and of mini-elements containing Al-U 3 Si 2 dispersion fuel, are presented. (orig.)

  6. Four-dimensional conversion for spiritual leadership development: A ...

    African Journals Online (AJOL)

    The process of a four-dimensional conversion and/or transformation strives in helping the leadership of an organisation, especially such as the church, with practical ways that may lead to the development of an effective leadership by observing the four important aspects of human spirituality as elaborated on in the article.

  7. Development of chemical conversion process of long-lived radionuclides

    International Nuclear Information System (INIS)

    Yoo, Jae Hyung; Lee, Byung Gik; Kang, Young Ho

    2001-05-01

    The objective of this project is to develop a conversion technology of long-lived radionuclides so that it can be a suitable form as a fuel or target in the nuclear transmutation system. During the first stage of the project (Apr 1997∼Mar 2001), the fundamental studies were performed with a focus on non-radioactive experiments as well as theoretical analyses in such areas as follows : fluorination of metals or metal oxides, electrorefining and electrowinning of actinides and lanthanides, pyro hydrolysis and regeneration of used molten salt. Since the chemical form of transuranium fuel in the transmutation system was assumed to be a molten fluoride, the electrolysis experiments of molten fluoride were conducted to study on the recovery of unused transuranium from the LiF-BeF 2 salt that was chosen as a basic salt medium. Fluorination of metals or metal oxides were also tested in this work by applying the method of three-phase (gas-liquid-solid) reaction. In the electrowinning experiments, the depositions of uranium, zirconium and niobium on the cathode were tested and analyzed. The electrorefining of lanthanides was studied with the salt media of FLINAK and FLICA and their behaviors were compared. In addition, the regeneration of used salts was examined by applying the method of electrolysis of molten salt, where alkali and alkali earth metals were found to be removed into the liquid lead cathode

  8. Static Scale Conversion Weigh-In-Motion System; FINAL

    International Nuclear Information System (INIS)

    Beshears, D.L.

    2001-01-01

    In support of the Air Mobility Battle Lab (AMBL), the Defense Advanced Research Projects Agency (DARPA) Advanced Logistics Program and the U. S. Transportation Command (USTRANSCOM), the ultimate objective of this project is to develop and demonstrate a full-scale prototype static scale conversion weigh-in-motion/Profilometry (SSC-WIM/P) system to measure and record dimensional and weight information for the Department of Defense (DoD) equipment and cargo. The Oak Ridge National Laboratory (ORNL), along with the AMBL, and Intercomp, Inc. have developed a long-range plan for developing a dual-use system which can be used as a standard static scale or an accurate weigh-in-motion system. AMBL will work to define requirements for additional activities with U.S. Transportation Command, Air Mobility Command, and the Joint Warfighting Battle Lab for both the SSC-WIM/P and a portable Weigh-in-Motion System for individual units. The funding goal is to fully fund the development of two prototype test articles (a SSC-WIM kit, and a laser profilometer) and have at least one fully operational system by the early 2002 timeframe. The objective of this portion of the project will be to develop a SSC-WIM system, which at a later date can be fully integrated with a profilometry system; to fully characterize DOD wheeled vehicles and cargo (individual axle weights, total vehicle weight, center of balance, height, width and length measurements). The program will be completed in phases with the initial AMBL/DARPA funding being used to initiate the efforts while AMBL/USTC obtains funding to complete the first generation system effort. At the completion of an initial effort, the interface hardware and the data acquisition/analysis hardware will be developed, fabricated, and system principles and basic functionality evaluated, tested, and demonstrated. Additional funding, when made available, will allow the successful completion of a first generation prototype system. This effort will be

  9. Closed Brayton cycle power conversion systems for nuclear reactors :

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vernon, Milton E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sanchez, Travis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2006-04-01

    This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at

  10. A system approach to high quality picture-rate conversion

    NARCIS (Netherlands)

    Bartels, C.L.L.; Cordes, C.N.; Riemens, B.; Haan, de G.

    2010-01-01

    Various techniques have been implemented to improve the motion portrayal of flat-panel displays, of which the widespread introduction of motion-compensated picture-rate conversion systems is an essential part. However, a careful design of such systems is critical as they have the potential to

  11. Gate controlled high efficiency ballistic energy conversion system

    NARCIS (Netherlands)

    Xie, Yanbo; Bos, Diederik; de Boer, Hans L.; van den Berg, Albert; Eijkel, Jan C.T.; Zengerle, R.

    2013-01-01

    Last year we demonstrated the microjet ballistic energy conversion system[1]. Here we show that the efficiency of such a system can be further improved by gate control. With gate control the electrical current generation is enhanced a hundred times with respect to the current generated from the zeta

  12. Materials science for solar energy conversion systems

    CERN Document Server

    Granqvist, CG

    1991-01-01

    Rapid advances in materials technology are creating many novel forms of coatings for energy efficient applications in solar energy. Insulating heat mirrors, selective absorbers, transparent insulation and fluorescent concentrators are already available commercially. Radiative cooling, electrochromic windows and polymeric light pipes hold promise for future development, while chemical and photochemical processes are being considered for energy storage. This book investigates new material advances as well as applications, costs, reliability and industrial production of existing materials. Each c

  13. Socio-economic overview of wind energy conversion systems

    International Nuclear Information System (INIS)

    Hardy, D.R.

    1992-01-01

    A social scientist's perspective is presented on the socio-economic impacts of wind energy conversion systems (WECS) in Ontario. The main organization for delivering electricity in Ontario is Ontario Hydro. This utility has two WECS, an experimental 3.5 kW generator and a hybrid wind/diesel facility at a remote northern community. Ontario Hydro is reviewing its supply options and anticipates wind power would likely be used in niche applications involving off-grid hybrid systems where the cost of displaced generation is high. On-grid applications would likely be in the form of dispersed non-utility generation. The potential contribution of wind power to Ontario's electricity supply mix could be as little as 1 MW by the year 2000 or as high as 40 MW by the year 2014, depending on costs and technological developments. Socio-economic criteria used by the utility for assessing individual supply options include job creation, regional economic development, local community impacts, social acceptance, and distribution of risks and benefits. Initial observations of potential effects of WECS are discussed, including site selection, manufacturing, construction, and operation. Barriers to implementation of WECS in Ontario include the limited number of good wind sites, the intermittent nature of WECS power, and the currently uneconomic nature of WECS for bulk electricity systems. However, WECS have environmentally attractive features and are socially acceptable. 10 refs., 3 figs

  14. Experimental model of a wind energy conversion system

    Science.gov (United States)

    Vasar, C.; Rat, C. L.; Prostean, O.

    2018-01-01

    The renewable energy domain represents an important issue for the sustainable development of the mankind in the actual context of increasing demand for energy along with the increasing pollution that affect the environment. A significant quota of the clean energy is represented by the wind energy. As a consequence, the developing of wind energy conversion systems (WECS) in order to achieve high energetic performances (efficiency, stability, availability, competitive cost etc) represents a topic of permanent actuality. Testing and developing of an optimized control strategy for a WECS direct implemented on a real energetic site is quite difficult and not cost efficient. Thus a more convenient solution consists in a flexible laboratory setup which requires an experimental model of a WECS. Such approach would allow the simulation of various real conditions very similar with existing energetic sites. This paper presents a grid-connected wind turbine emulator. The wind turbine is implemented through a real-time Hardware-in-the-Loop (HIL) emulator, which will be analyzed extensively in the paper. The HIL system uses software implemented in the LabVIEW programming environment to control an ABB ACS800 electric drive. ACS800 has the task of driving an induction machine coupled to a permanent magnet synchronous generator. The power obtained from the synchronous generator is rectified, filtered and sent to the main grid through a controlled inverter. The control strategy is implemented on a NI CompactRIO (cRIO) platform.

  15. Perspectives of photovoltaic conversion development in the world

    International Nuclear Information System (INIS)

    Chiron, P.

    2007-01-01

    The present day economical context is favourable to the development of renewable energy sources: high fossil fuel prices, public awareness about environmental problems, etc. The incentive measures implemented by public authorities (regulation, repurchase tariff, tax credits etc.) have permitted to overcome the competitiveness handicap. This favorable framework should last long thanks to the strong support of the European Union. This market study deals with the photovoltaic conversion industry and answers the following questions: what is the world market growth of photovoltaic conversion? What are the most flourishing applications? What are the best oriented markets? How heavy is the world market? What is the degree of competitiveness of this industry? What is the development potential of this market? Who are the best-positioned groups to profit of it? What is the progress of the sector structuration? What is the future of pure players? (J.S.)

  16. Systems modeling for a laser-driven IFE power plant using direct conversion

    International Nuclear Information System (INIS)

    Meier, W R

    2008-01-01

    A variety of systems analyses have been conducted for laser driver IFE power plants being developed as part of the High Average Power Laser (HAPL) program. A key factor determining the economics attractiveness of the power plant is the net power conversion efficiency which increases with increasing laser efficiency, target gain and fusion-to-electric power conversion efficiency. A possible approach to increasing the power conversion efficiency is direct conversion of ionized target emissions to electricity. This study examines the potential benefits of increased efficiency when the expanding plasma is inductively coupled to an external circuit allowing some of the ion energy to be directly converted to electricity. For base case direct-drive targets with approximately 24% of the target yield in ions, the benefits are modest, especially for chamber designs that operate at high temperature and thus already have relatively high thermal conversion efficiencies. The reduction in the projected cost of electricity is ∼5-10%

  17. 5 CFR 9901.371 - Conversion into NSPS pay system.

    Science.gov (United States)

    2010-01-01

    ... Section 9901.371 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF DEFENSE NATIONAL....231 for conversion rules related to determining an employee's career group, pay schedule, and band...

  18. 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

  19. Novel, Integrated Reactor / Power Conversion System (LMR-AMTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Pablo Rubiolo, Principal Investigator

    2003-03-21

    The main features of this project were the development of a long life (up to 10 years) Liquid Metal Reactor (LMR) and a static conversion subsystem comprising an Alkali Metal Thermal-to-Electric (AMTEC) topping cycle and a ThermoElectric (TE) Bottom cycle. Various coupling options of the LMR with the energy conversion subsystem were explored and, base in the performances found in this analysis, an Indirect Coupling (IC) between the LMR and the AMTEC/TE converters with Alkali Metal Boilers (AMB) was chosen as the reference design. The performance model of the fully integrated sodium-and potassium-AMTEC/TE converters shows that a combined conversion efficiency in excess of 30% could be achieved by the plant. (B204)

  20. The state of the art of wind energy conversion systems and technologies: A review

    International Nuclear Information System (INIS)

    Cheng, Ming; Zhu, Ying

    2014-01-01

    Highlights: • This paper reviews the state of the art of wind energy conversion systems. • Different types of common wind energy conversion systems are classified and compared. • The four most popular MPPT control methods are reviewed and compared. • The latest development of wind energy conversion technologies is introduced. • Future trends of the wind energy conversion technologies are discussed. - Abstract: This paper gives a comprehensive review of the state of the art of wind energy conversion systems (WECS) and technologies, with an emphasis on wind power generator and control. First, different types of common WECSs are classified according to their features and drive train types. The WECSs are compared on the basis of the volume, weight, cost, efficiency, system reliability and fault ride through capability. The maximum power point tracking (MPPT) control, which aims to make the generator speed meet an optimum value to ensure the maximum energy yield, plays a key role in the variable speed WECSs. A comprehensive review and comparison of the four most popular MPPT control methods are carried out and improvements for each method are presented. Furthermore, the latest development of wind energy conversion technologies is introduced, such as the brushless doubly fed induction generator (BDFIG), the stator permanent magnet synchronous generators, the magnetic-geared generators, dual power flow WECS with the electrical variable transmission (EVT) machine, and direct grid-connected WECS. Finally, the future trends of the technologies are discussed

  1. Thermodynamic limits to the conversion of blackbody radiation by quantum systems. [with application to solar energy conversion devices

    Science.gov (United States)

    Buoncristiani, A. M.; Smith, B. T.; Byvik, C. E.

    1982-01-01

    Using general thermodynamic arguments, we analyze the conversion of the energy contained in the radiation from a blackbody to useful work by a quantum system. We show that the energy available for conversion is bounded above by the change in free energy in the incident and reradiated fields and that this free energy change depends upon the temperature of the receiving device. Universal efficiency curves giving the ultimate thermodynamic conversion efficiency of the quantum system are presented in terms of the blackbody temperature and the temperature and threshold energy of the quantum system. Application of these results is made to a variety of systems including biological photosynthetic, photovoltaic, and photoelectrochemical systems.

  2. Intelligent control with implementation on the wind energy conversion system

    International Nuclear Information System (INIS)

    Basma, Mohamad Khalil

    1997-05-01

    In this thesis our main job is to compare intelligent control and conventional control algorithms, by applying each scheme to the same control problem. Based on simulation, we analyze and compare the results of applying fuzzy logic and neural networks controllers on a popular control problem: variable speed wind energy conversion system. The reason behind our choice is the challenging nature of the problem where the plant should be controlled to maximize the power generated, while respecting its hardware constraints under varying operating conditions and disturbances. We have shown the effectiveness of fuzzy logic exciter controller for the adopted wind energy generator when compared to a conventional PI exciter. It showed better performance in the whole operating range. However, in the high wind speeds region, both controllers were unable to deliver the rpm requirements. We proposed the use of neural network intelligent techniques to supply us the optimal pitch. Our aim was to develop a simple and reliable controller that can deliver this optimal output, while remaining adaptive to system uncertainties and disturbances. The proposed fuzzy controller with a neural pitch controller showed best dynamic and robust performance as compared to the adaptive pitch controller together with the PI exciter. This study has shown that artificial neural networks and fuzzy logic control algorithms can be implemented for real time control implementations. the neuro-fuzzy control approach is robust and its performance is superior to that of traditional control methods. (author)

  3. Status of NASA's Advanced Radioisotope Power Conversion Technology Research and Development

    Science.gov (United States)

    Wong, Wayne A.; Anderson, David J.; Tuttle, Karen L.; Tew, Roy C.

    2006-01-01

    NASA s Advanced Radioisotope Power Systems (RPS) development program is funding the advancement of next generation power conversion technologies that will enable future missions that have requirements that can not be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power Systems (RPS). Requirements of advanced radioisotope power systems include high efficiency and high specific power (watts/kilogram) in order to meet mission requirements with less radioisotope fuel and lower mass. Other Advanced RPS development goals include long-life, reliability, and scalability so that these systems can meet requirements for a variety of future space applications including continual operation surface missions, outer-planetary missions, and solar probe. This paper provides an update on the Radioisotope Power Conversion Technology Project which awarded ten Phase I contracts for research and development of a variety of power conversion technologies consisting of Brayton, Stirling, thermoelectrics, and thermophotovoltaics. Three of the contracts continue during the current Phase II in the areas of thermoelectric and Stirling power conversion. The accomplishments to date of the contractors, project plans, and status will be summarized.

  4. Ocean thermal energy conversion power system development-I. Preliminary design report. Volume 3. Appendixes D, E, and F. Phase I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-18

    The conceptual design of a 40 to 50 MW closed cycle ammonia OTEC commercial plant, the preliminary design of a 10 MW OTEC module analogous to the 50 MW module, and the preliminary design of heat exchanger test articles (evaporator and condenser) representative of the 50 MW heat exchangers for testing in OTEC-1 are presented. This volume includes the appendices: D) system equipment (hardware breakdown structure; 10-MW hardware listing; list of support and maintenance equipment, tools and spare parts; sacrificial anodes; M.A.N. brush; and Alclad 3004 data); E) heat exchanger supporting data (analyses/configuration, contract tooling, manufacturing plan, specification, and evaporator ammonia liquid distribution system); and F) rotating machinery (performance characteristics, radial inflow turbine; item descriptions; weight calculation-rotor; producibility analysis; long lead-time items; spares; support equipment; non recurring costs; performance characteristics-axial flow turbine; Worthington pump data; and American M.A.N. Corporation data). Also included is attachment 1 to the phase I final report which presents details of the system modeling; design, materials considerations, and systems analysis of the baseline module; system cost analysis; and supporting data. (WHK)

  5. Physical Limits of Solar Energy Conversion in the Earth System.

    Science.gov (United States)

    Kleidon, Axel; Miller, Lee; Gans, Fabian

    2016-01-01

    Solar energy provides by far the greatest potential for energy generation among all forms of renewable energy. Yet, just as for any form of energy conversion, it is subject to physical limits. Here we review the physical limits that determine how much energy can potentially be generated out of sunlight using a combination of thermodynamics and observed climatic variables. We first explain how the first and second law of thermodynamics constrain energy conversions and thereby the generation of renewable energy, and how this applies to the conversions of solar radiation within the Earth system. These limits are applied to the conversion of direct and diffuse solar radiation - which relates to concentrated solar power (CSP) and photovoltaic (PV) technologies as well as biomass production or any other photochemical conversion - as well as solar radiative heating, which generates atmospheric motion and thus relates to wind power technologies. When these conversion limits are applied to observed data sets of solar radiation at the land surface, it is estimated that direct concentrated solar power has a potential on land of up to 11.6 PW (1 PW=10(15) W), whereas photovoltaic power has a potential of up to 16.3 PW. Both biomass and wind power operate at much lower efficiencies, so their potentials of about 0.3 and 0.1 PW are much lower. These estimates are considerably lower than the incoming flux of solar radiation of 175 PW. When compared to a 2012 primary energy demand of 17 TW, the most direct uses of solar radiation, e.g., by CSP or PV, have thus by far the greatest potential to yield renewable energy requiring the least space to satisfy the human energy demand. Further conversions into solar-based fuels would be reduced by further losses which would lower these potentials. The substantially greater potential of solar-based renewable energy compared to other forms of renewable energy simply reflects much fewer and lower unavoidable conversion losses when solar

  6. FY1995 design of environment-friendly and generation-type conversion title of system for unused carbon resources by developing highly functional materials; 1995 nendo kokino zakryo kaihatsu ni yoru kankyo chowagata jisedai miriyo tanso shigen tenkan system no kochiku

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Carbon resources such as coal, heavy oil, bitumen and so on are not suitable for the utilization as energy resources from the view-point of the global environment because those contain a great deal of heteroatoms, minerals and water. Therefore, the purpose of this project is to establish the environment-friendly and next generation-type conversion system for unused carbon resources by developing highly functional materials. This project aims at the following researches necessary to establish the conversion system for the unused carbon resources. (1) Development of technologies for pre-treating carbon resources (2) Development of recoverable hydrogenation catalysts capable of repeated use (3) Development of gasification catalysts active at low temperatures (4) Development of inorganic membranes for H{sub 2} or CO{sub 2} separation (5) Development of adsorption separation technologies in the supercritical phase (6) Development of highly active catalysts for CO hydrogenation Each development has been successfully completed and we have much prospect of establishing the conversion system for unused carbon resources. (NEDO)

  7. Development and testing of a 1/10 scale self-rectifying air turbine power conversion system. For period December 1979 to February 1981

    Energy Technology Data Exchange (ETDEWEB)

    White, P.R.S.

    1981-08-01

    In December 1979 the SEA-Lanchester Wave Energy Group started a programme of theoretical and experimental work to investigate the performance of a self-rectifying air turbine based on the idea first proposed by Dr. A.A. Wells. The work was initiated to provide the project team with accurate design data for the power take off in order that the complete system performance could be analysed. It was felt necessary to provide this data in house, as at that time no results were available from the other groups working with self rectifying air turbines. The result of the work described in the report is that a self rectifying turbine of the Wells type provides a very efficient, elegant, simple and therefore reliable, solution to the power take off aspect of the CLAM Wave Energy Converter.

  8. GT-MHR power conversion system: Design status and technical issues

    International Nuclear Information System (INIS)

    Etzel, K.; Baccaglini, G.; Schwartz, A.; Hillman, S.; Mathis, D.

    1994-12-01

    The Modular Helium Reactor (MHR) builds on 30 years of international gas-cooled reactor experience utilizing the unique properties of helium gas coolant, graphite moderator and coated particle fuel. To efficiently utilize the high temperature potential of the MHR, an innovative power conversion system has been developed featuring an intercooled and recuperated gas turbine. The gas turbine replaces a conventional steam turbine and its many auxiliary components. The Power Conversion System converts the thermal energy of the helium directly into electrical energy utilizing a closed Brayton cycle. The Power Conversion System draws on even more years of experience than the MHR: the world's first closed-cycle plant, fossil fired and utilizing air as working fluid, started operation in Switzerland in 1939. Shortly thereafter, in 1945, the coupling of a closed-cycle plant to a nuclear heat generation system was conceived. Directly coupling the closed-cycle gas turbine concept to a modern, passively safe nuclear reactor opens a new chapter in power generation technology and brings with it various design challenges. Some of these challenges are associated with the direct coupling of the Power Conversion System to a nuclear reactor. Since the primary coolant is also the working fluid, the Power Conversion System has to be designed for reactor radionuclide plateout. As a result, issues like component maintainability and replaceability, and fission product effects on materials must be addressed. Other issues concern the integration of the Power Conversion System components into a single vessel. These issues include the selection of key technologies for the power conversion components such as submerged generator, magnetic bearings, seals, compact heat exchangers, and the overall system layout

  9. Direct energy conversion system for D-3He fusion

    International Nuclear Information System (INIS)

    Tomita, Y.; Shu, L.Y.; Momota, H.

    1993-11-01

    A novel and highly efficient direct energy conversion system is proposed for utilizing D- 3 He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to 'LINAC.' The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DECs bring about the high efficient fusion plant. (author)

  10. Conversion to biofuel based heating systems - local environmental effects

    International Nuclear Information System (INIS)

    Jonsson, Anna

    2003-01-01

    One of the most serious environmental problems today is the global warming, i.e.climate changes caused by emissions of greenhouse gases. The greenhouse gases originate from combustion of fossil fuels and changes the atmospheric composition. As a result of the climate change, the Swedish government has decided to make a changeover of the Swedish energy system. This involves an increase of the supply of electricity and heating from renewable energy sources and a decrease in the amount electricity used for heating, as well as a more efficient use of the existing electricity system. Today, a rather large amount electricity is used for heating in Sweden. Furthermore, nuclear power will be phased out by the year 2010 in Sweden. Bio fuels are a renewable energy source and a conceivable alternative to the use of fossil fuels. Therefore, an increase of bio fuels will be seen the coming years. Bio fuels have a lot of environmental advantages, mainly for the global environment, but might also cause negative impacts such as depletion of the soils where the biomass is grown and local deterioration of the air quality where the bio fuels are combusted. These negative impacts are a result of the use of wrong techniques and a lack of knowledge and these factors have to be improved if the increase of the use of bio fuels is to be made effectively. The aim of this master thesis is to evaluate the possibilities for heating with bio fuel based systems in housing areas in the municipalities of Trollhaettan, Ulricehamn and Goetene in Vaestra Goetalands County in the South West of Sweden and to investigate which environmental and health effects are caused by the conversion of heating systems. The objective is to use the case studies as examples on preferable bio fuel based heating systems in different areas, and to what environmental impact this conversion of heating systems might cause. The housing areas for this study have been chosen on the basis of present heating system, one area

  11. Analysis of dynamic effects in solar thermal energy conversion systems

    Science.gov (United States)

    Hamilton, C. L.

    1978-01-01

    The paper examines a study the purpose of which is to assess the performance of solar thermal power systems insofar as it depends on the dynamic character of system components and the solar radiation which drives them. Using a dynamic model, the daily operation of two conceptual solar conversion systems was simulated under varying operating strategies and several different time-dependent radiation intensity functions. These curves ranged from smoothly varying input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours.

  12. Development of a conversational text editor on MITRA 125 used with a TEKTRONIX 4014 display console

    International Nuclear Information System (INIS)

    Siffre, Evelyne.

    1980-06-01

    The purpose of this study, which falls within the purview of a nuclear physics research laboratory, is the development of a simple to use conversational text editor to mitigate the defects of the MMT2 monitor. The operations to be executed are: - creation of a source file written in FORTRAN - concatenation of the various stages to obtain a workable program: FORTRAN compilation, edition of links, group generation; - execution of this program. These operations are performed in two different ways: 1) by using the system controls as from the teleprinter (this corresponds to the previous use). The sequence of controls to be effected is described; 2) by using the EDI 125 conversational editor [fr

  13. Solid waste information and tracking system client-server conversion project management plan

    International Nuclear Information System (INIS)

    May, D.L.

    1998-01-01

    This Project Management Plan is the lead planning document governing the proposed conversion of the Solid Waste Information and Tracking System (SWITS) to a client-server architecture. This plan presents the content specified by American National Standards Institute (ANSI)/Institute of Electrical and Electronics Engineers (IEEE) standards for software development, with additional information categories deemed to be necessary to describe the conversion fully. This plan is a living document that will be reviewed on a periodic basis and revised when necessary to reflect changes in baseline design concepts and schedules. This PMP describes the background, planning and management of the SWITS conversion. It does not constitute a statement of product requirements. Requirements and specification documentation needed for the SWITS conversion will be released as supporting documents

  14. 24 CFR 972.124 - Standards for identifying public housing developments subject to required conversion.

    Science.gov (United States)

    2010-04-01

    ... March 16, 2009, the specified vacancy rate is 15 percent. For a conversion analysis performed after that... housing developments subject to required conversion. 972.124 Section 972.124 Housing and Urban Development... INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT CONVERSION OF PUBLIC HOUSING TO TENANT-BASED...

  15. Characteristic of oil palm residue for energy conversion system

    International Nuclear Information System (INIS)

    Muharnif; Zainal, Z.A.

    2006-01-01

    Malaysia is the major producer of palm oil in the world. It produces 8.5 tones per year (8.5 x 10 6 ty -1 ) of palm oil from 38.6 x 10 6 ty - 1 of fresh fruit bunches. Palm oil production generates large amounts of process residue such as fiber (5.4 x 10 6 ty - 1 ), shell (2.3 x 10 6 ty - 1 ), and empty fruit bunches (8.8 x 10 6 ty - 1 ). A large fraction of the fiber and much of the shell are used as fuel to generate process steam and electricity. The appropriate energy conversion system depends on the characteristic of the oil palm residue. In this paper, a description of characteristic of the oil palm residue is presented. The types of the energy conversion system presented are stoker type combustor and gasified. The paper focuses on the pulverized biomass material and the use of fluidized bed gasified. In the fluidized bed gasified, the palm shell and fiber has to be pulverized before feeding into gasified. For downdraft gasified and furnace, the palm shell and fiber can be used directly into the reactor for energy conversion. The heating value, burning characteristic, ash and moisture content of the oil palm residue are other parameters of the study

  16. Code conversion for system design and safety analysis of NSSS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hae Cho; Kim, Young Tae; Choi, Young Gil; Kim, Hee Kyung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-01-01

    This report describes overall project works related to conversion, installation and validation of computer codes which are used in NSSS design and safety analysis of nuclear power plants. Domain/os computer codes for system safety analysis are installed and validated on Apollo DN10000, and then Apollo version are converted and installed again on HP9000/700 series with appropriate validation. Also, COOLII and COAST which are cyber version computer codes are converted into versions of Apollo DN10000 and HP9000/700, and installed with validation. This report details whole processes of work involved in the computer code conversion and installation, as well as software verification and validation results which are attached to this report. 12 refs., 8 figs. (author)

  17. U.S. Department Of Energy's nuclear engineering education research: highlights of recent and current research-I. 7. The Research and Development of the Radioisotope Energy Conversion System

    International Nuclear Information System (INIS)

    Steinfelds, Eric V.; Ghosh, Tushar K.; Prelas, Mark A.; Tompson, Robert V.; Loyalka, Sudarshan K.

    2001-01-01

    The topic of this paper is the development of the radioisotope energy conversion system (RECS) in a project that utilizes analytical computational assisted design and laboratory research. RECSs shall supplement and ideally replace the radioactive thermal generator (RTG) power systems, which supply the crucial electricity currently on the deep space mission capsules and potentially on future satellites. Indeed, a very efficient radiation-driven electrical generator presents many advantages over a solar-driven generator. RTG systems used by the United States (i.e., Voyager spacecraft) have a maximum efficiency in electrical power from a radiative kinetic power of only 8%.A 238 Pu-driven RECS could have an efficiency of 20% in the ratio of electrical power over radiative kinetic power. Some RECSs driven radiatively by isotopes other than 238 Pu could potentially have efficiencies somewhat higher than 20%. This efficiency is due to the involvement of mediating fluorescing gas. For example, an energy conversion system that uses fission for its power source and has fluorescing ionic mediators plus robust photovoltaic cells could have efficiencies as high as 40% (Refs. 2 and 3). Indeed, a compact generator system of even 20% efficiency is better than a compact system with only 8% efficiency (of RTG). The promise of a high-efficiency, durable energy conversion system affirmatively justifies the committed research and development of RECS. RECS consists of the following components: 1. a radioisotope for producing fluxes of particles; 2. ambient fluorescent gas that readily produces photons at the blue and ultraviolet range when energetically perturbed; 3. photovoltaic cells to convert the blue and ultraviolet photons into electrical energy; 4. electrical circuitry that includes a load in order to harness the converted energy. The ambient fluorescent gas shall either surround or be mixed 'homogeneously' with the radioisotope material. The radioisotope material shall be either

  18. Development of suspended core soft glass fibers for far-detuned parametric conversion

    Science.gov (United States)

    Rampur, Anupamaa; Ciąćka, Piotr; Cimek, Jarosław; Kasztelanic, Rafał; Buczyński, Ryszard; Klimczak, Mariusz

    2018-04-01

    Light sources utilizing χ (2) parametric conversion combine high brightness with attractive operation wavelengths in the near and mid-infrared. In optical fibers, it is possible to use χ (3) degenerate four-wave mixing in order to obtain signal-to-idler frequency detuning of over 100 THz. We report on a test series of nonlinear soft glass suspended core fibers intended for parametric conversion of 1000-1100 nm signal wavelengths available from an array of mature lasers into the near-to-mid-infrared range of 2700-3500 nm under pumping with an erbium sub-picosecond laser system. The presented discussion includes modelling of the fiber properties, details of their physical development and characterization, and experimental tests of parametric conversion.

  19. Work Began on Contracts for Radioisotope Power Conversion Technology Research and Development

    Science.gov (United States)

    Wong, Wayne A.

    2005-01-01

    NASA has had a history of successful space flight missions that depended on radioisotope-fueled power systems. These Radioisotope Power Systems (RPSs) converted the heat generated from the decay of radioisotope material into useful electrical power. An RPS is most attractive in applications where photovoltaics are not optimal, such as deep-space applications where the solar flux is too low or extended applications on planets such as Mars where the day/night cycle, settling of dust, and life requirements limit the usefulness of photovoltaics. NASA s Radioisotope Power Conversion Technology (RPCT) Program is developing next-generation power-conversion technologies that will enable future missions that have requirements that cannot be met by the two RPS flight systems currently being developed by the Department of Energy for NASA: the Multi-Mission Radioisotope Thermoelectric Generator and the Stirling Radioisotope Generator (SRG).

  20. Onboard energy conversion and thermal analysis of the MTL system

    International Nuclear Information System (INIS)

    Kadiramangalam, M.N.; Hoffert, M.I.; Miller, G.

    1989-01-01

    A non-nuclear energy conversion concept-MTL (microwave power to low earth orbits) was previously presented in order to supply SDI platforms power in the housekeeping, alert and burst power modes. In this paper the major issues addressed are: system design, integration and analysis. Parametric design of the major subsystems of the MTL bus, which includes the rectenna, the monolithic solid oxide fuel cell etc., is presented. The results of the parametric design, and of computer simulation are used as inputs to construct a comprehensive systems design code. A reference MTL system design which meets the requirements of duty cycles spelled out in open literature is presented. A comparison of mass and power is made between the MTL system and the SP-100 and burst power systems, which demonstrates the competitiveness of the proposed MTL design

  1. Reactor technology: power conversion systems and reactor operation and maintenance

    International Nuclear Information System (INIS)

    Powell, J.R.

    1977-01-01

    The use of advanced fuels permits the use of coolants (organic, high pressure helium) that result in power conversion systems with good thermal efficiency and relatively low cost. Water coolant would significantly reduce thermal efficiency, while lithium and salt coolants, which have been proposed for DT reactors, will have comparable power conversion efficiencies, but will probably be significantly more expensive. Helium cooled blankets with direct gas turbine power conversion cycles can also be used with DT reactors, but activation problems will be more severe, and the portion of blanket power in the metallic structure will probably not be available for the direct cycle, because of temperature limitations. A very important potential advantage of advanced fuel reactors over DT fusion reactors is the possibility of easier blanket maintenance and reduced down time for replacement. If unexpected leaks occur, in most cases the leaking circuit can be shut off and a redundant cooling curcuit will take over the thermal load. With the D-He 3 reactor, it appears practical to do this while the reactor is operating, as long as the leak is small enough not to shut down the reactor. Redundancy for Cat-D reactors has not been explored in detail, but appears feasible in principle. The idea of mobile units operating in the reactor chamber for service and maintenance of radioactive elements is explored

  2. Artificial vesicles with incorporated photosynthetic materials for potential solar energy conversion systems

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2009-07-01

    Full Text Available WITH INCORPORATED PHOTOSYNTHETIC MATERIALS FOR POTENTIAL SOLAR ENERGY CONVERSION SYSTEMS J E Smit1, A F Grobler2, A E Karsten1, R W Sparrow3 1 CSIR National Laser Centre, PO Box 395, Pretoria, 0001, South Africa 2 Unit for drug development and research, North...

  3. Innovative power conversion system for the French SFR prototype, ASTRID

    International Nuclear Information System (INIS)

    Cachon, L.; Biscarrat, C.; Morin, F.; Haubensack, D.; Rigal, E.; Moro, I.; Baque, F.; Madeleine, S.; Rodriguez, G.; Laffont, G.

    2012-01-01

    In the framework of the French Act of 28 June 2006 about nuclear materials and waste management, the prototype ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration), foreseen in operation by the 20's, will have to demonstrate not only the minor actinide transmutation capability, but also the progress made in Sodium Fast Reactor (SFR) technology on an industrial scale, by qualifying innovative options. Some of these options still require improvements, especially in the field of operability and safety. In fact, one of the main issues with the standard steam/water Power Conversion System (PCS) of SFR is the fast and energetic chemical reaction between water and sodium, which could occur in steam generators in case of tube failure. To manage the sodium/water reaction, one way consists in minimizing the impact of such event: hence studies are carried out on steam generator design, improvement of the physical knowledge of this phenomenon, development of numerical simulation to predict the reaction onset and consequences, and associated detection improvement. On the other hand, the other way consists in eliminating sodium/water reaction. In this frame, the CEA contribution to the feasibility evaluation of an alternative innovative PCS (replacing steam/water by 180 bar pressurised nitrogen) is focused on the following main topics: - The parametric study leading to nitrogen selection: the thermodynamic cycle efficiency optimisation on Brayton cycles is performed with several gases at different pressures. - The design of innovative compact heat exchangers for the gas loop: here the key points are the nuclear codification associated with inspection capability, the innovative welding process and the thermal-hydraulic and thermal-mechanic optimisations. After a general introduction of the ASTRID project, this paper presents in detail these different feasibility studies being led on the innovative gas PCS for an SFR. (authors)

  4. Analytical investigation of low temperature lift energy conversion systems with renewable energy source

    International Nuclear Information System (INIS)

    Lee, Hoseong; Hwang, Yunho; Radermacher, Reinhard

    2014-01-01

    The efficiency of the renewable energy powered energy conversion system is typically low due to its moderate heat source temperature. Therefore, improving its energy efficiency is essential. In this study, the performance of the energy conversion system with renewable energy source was theoretically investigated in order to explore its design aspect. For this purpose, a computer model of n-stage low temperature lift energy conversion (LTLEC) system was developed. The results showed that under given operating conditions such as temperatures and mass flow rates of heat source and heat sink fluids the unit power generation of the system increased with the number of stage, and it became saturated when the number of staging reached four. Investigation of several possible working fluids for the optimum stage LTLEC system revealed that ethanol could be an alternative to ammonia. The heat exchanger effectiveness is a critical factor on the system performance. The power generation was increased by 7.83% for the evaporator and 9.94% for the condenser with 10% increase of heat exchanger effectiveness. When these low temperature source fluids are applied to the LTLEC system, the heat exchanger performance would be very critical and it has to be designed accordingly. - Highlights: •Energy conversion system with renewable energy is analytically investigated. •A model of multi-stage low temperature lift energy conversion systems was developed. •The system performance increases as the stage number is increased. •The unit power generation is increased with increase of HX effectiveness. •Ethanol is found to be a good alternative to ammonia

  5. 5 CFR 9901.231 - Conversion of positions and employees to NSPS classification system.

    Science.gov (United States)

    2010-01-01

    ... HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF DEFENSE NATIONAL SECURITY PERSONNEL SYSTEM (NSPS) Classification Transitional... employee's career group, pay schedule, and band upon conversion. (d) Grade retention prior to conversion...

  6. Two-Stage Variable Sample-Rate Conversion System

    Science.gov (United States)

    Tkacenko, Andre

    2009-01-01

    A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

  7. In situ conversion process utilizing a closed loop heating system

    Science.gov (United States)

    Sandberg, Chester Ledlie [Palo Alto, CA; Fowler, Thomas David [Houston, TX; Vinegar, Harold J [Bellaire, TX; Schoeber, Willen Jan Antoon Henri

    2009-08-18

    An in situ conversion system for producing hydrocarbons from a subsurface formation is described. The system includes a plurality of u-shaped wellbores in the formation. Piping is positioned in at least two of the u-shaped wellbores. A fluid circulation system is coupled to the piping. The fluid circulation system is configured to circulate hot heat transfer fluid through at least a portion of the piping to form at least one heated portion of the formation. An electrical power supply is configured to provide electrical current to at least a portion of the piping located below an overburden in the formation to resistively heat at least a portion of the piping. Heat transfers from the piping to the formation.

  8. Transient behavior of ASTRID with a gas power conversion system

    International Nuclear Information System (INIS)

    Bertrand, F.; Mauger, G.; Bensalah, M.; Gauthé, P.

    2016-01-01

    Highlights: • CATHARE2 transient calculations have been performed for ASTRID with a gas PCS. • The behavior of the reactor is close for gas and for water PCS in case of LOOP. • The gas PCS enables to cool the core for at least 10 h for pressurized transients. • The depressurization of the PCS induces an over-cooling for breaches on low pressure pipes. • The spurious opening of a by-pass line of the turbomachine can be controlled without scram. - Abstract: The present article is dedicated to preliminary transient studies carried out for the analysis of the system overall behavior of the ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) demonstrator developed in France by CEA and its industrial partners. ASTRID is foreseen to demonstrate the progress made in SFR technology at an industrial scale by qualifying innovative options, some of which still remain open in the areas requiring improvements, especially safety and operability. Among the innovative options, a gas power conversion systems (PCS) is envisaged. In this innovative PCS, the working gas is nitrogen whose flow rate delivers power to a turbine driving with the same shaft two compressors (low and high pressure) separated by an intercooler. The other part of the work delivered by the gas is used to drive the alternator that produces electricity. The main objective of such a PCS consists in avoiding physically the possibility of a sodium/water reaction with the secondary circuit but the impact of this PCS on the control of incidental and accidental transients has also been studied. The main purpose of the studies presented in the paper is to assess the dynamic behavior of ASTRID including a gas PCS with the CATHARE2 code. The first transient presented deals with a loss of off-site power and has been calculated for the gas PCS but also for a classical steam/water PCS for comparison purpose. Then typical transients of gas system have been investigated. Several families of

  9. Transient behavior of ASTRID with a gas power conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, F., E-mail: frederic.bertrand@cea.fr; Mauger, G.; Bensalah, M.; Gauthé, P.

    2016-11-15

    Highlights: • CATHARE2 transient calculations have been performed for ASTRID with a gas PCS. • The behavior of the reactor is close for gas and for water PCS in case of LOOP. • The gas PCS enables to cool the core for at least 10 h for pressurized transients. • The depressurization of the PCS induces an over-cooling for breaches on low pressure pipes. • The spurious opening of a by-pass line of the turbomachine can be controlled without scram. - Abstract: The present article is dedicated to preliminary transient studies carried out for the analysis of the system overall behavior of the ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) demonstrator developed in France by CEA and its industrial partners. ASTRID is foreseen to demonstrate the progress made in SFR technology at an industrial scale by qualifying innovative options, some of which still remain open in the areas requiring improvements, especially safety and operability. Among the innovative options, a gas power conversion systems (PCS) is envisaged. In this innovative PCS, the working gas is nitrogen whose flow rate delivers power to a turbine driving with the same shaft two compressors (low and high pressure) separated by an intercooler. The other part of the work delivered by the gas is used to drive the alternator that produces electricity. The main objective of such a PCS consists in avoiding physically the possibility of a sodium/water reaction with the secondary circuit but the impact of this PCS on the control of incidental and accidental transients has also been studied. The main purpose of the studies presented in the paper is to assess the dynamic behavior of ASTRID including a gas PCS with the CATHARE2 code. The first transient presented deals with a loss of off-site power and has been calculated for the gas PCS but also for a classical steam/water PCS for comparison purpose. Then typical transients of gas system have been investigated. Several families of

  10. Life cycle integrated thermoeconomic assessment method for energy conversion systems

    International Nuclear Information System (INIS)

    Kanbur, Baris Burak; Xiang, Liming; Dubey, Swapnil; Choo, Fook Hoong; Duan, Fei

    2017-01-01

    Highlights: • A new LCA integrated thermoeconomic approach is presented. • The new unit fuel cost is found 4.8 times higher than the classic method. • The new defined parameter increased the sustainability index by 67.1%. • The case studies are performed for countries with different CO 2 prices. - Abstract: Life cycle assessment (LCA) based thermoeconomic modelling has been applied for the evaluation of energy conversion systems since it provided more comprehensive and applicable assessment criteria. This study proposes an improved thermoeconomic method, named as life cycle integrated thermoeconomic assessment (LCiTA), which combines the LCA based enviroeconomic parameters in the production steps of the system components and fuel with the conventional thermoeconomic method for the energy conversion systems. A micro-cogeneration system is investigated and analyzed with the LCiTA method, the comparative studies show that the unit cost of fuel by using the LCiTA method is 3.8 times higher than the conventional thermoeconomic model. It is also realized that the enviroeconomic parameters during the operation of the system components do not have significant impacts on the system streams since the exergetic parameters are dominant in the thermoeconomic calculations. Moreover, the improved sustainability index is found roundly 67.2% higher than the previously defined sustainability index, suggesting that the enviroeconomic and thermoeconomic parameters decrease the impact of the exergy destruction in the sustainability index definition. To find the feasible operation conditions for the micro-cogeneration system, different assessment strategies are presented. Furthermore, a case study for Singapore is conducted to see the impact of the forecasted carbon dioxide prices on the thermoeconomic performance of the micro-cogeneration system.

  11. Installation places of criticality accident detectors in the plutonium conversion development facility

    International Nuclear Information System (INIS)

    Sanada, Yukihisa; Tsujimura, Norio; Shimizu, Yoshio; Izaki, Kenji; Furuta, Sadaaki

    2008-01-01

    At the Plutonium Conversion Development Facility (PCDF) in the Nuclear Fuel Cycle Engineering Laboratories, the co-conversion technologies to purify the mixed plutonium and uranium nitrate solution discharged from a reprocessing plant have been developed. The probability of a criticality accident in PCDF is extremely low. However, the criticality accident alarm system (CAAS) has been in place since 1982 to reduce the radiation dose to workers in case of such a rare criticality accident. The CAAS contains criticality accident detector units (CADs), one unit consisting of three plastic scintillation detectors, and using the 2 out of 3 voting system for the purpose of high reliability. Currently, eight CADs are installed in PCDF evaluating the dose using a simple equation allowing for a safety margin. The purpose of this study is to show the determination procedures for the adequate relocation of the CADs which adequately ensures safety in PCDF. (author)

  12. Design of environment-friendly and next generation-type conversion system for unused carbon resources by developing highly functional materials; Kokino zairyo kaihatsu ni yoru kankyo chowagata jisedai miriyo tanso shigen tenkan system no kochiku

    Energy Technology Data Exchange (ETDEWEB)

    Wakabayashi, K; Morooka, S; Arai, Y [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Sakanishi, K [Kyushu University, Fukuoka (Japan). Institute of Advanced Material Study

    1997-02-01

    Studies are conducted for the development of now-unused kinds of fossil carbon resources, such as low rank coal and heavy gravity crude oil, into higher-value liquid fuel. In the preliminary treatment process, the fossil carbon resources are dried by use of supercritical carbon dioxide, when it is found that the resources are disintegrated and water is desorbed. In a low rank coal liquefaction process using the NiMo/KB (Kefjen Black) catalyst, more than 60% is converted into oil, which rate is improved by use of the dual-temperature liquefaction process. This catalyst may be recovered by separation utilizing specific gravity difference. As a low temperature gasification catalyst, the alkaline carbonate-carried carbon catalyst is very quick at the initial stage of reaction. The perovskite-carried alkaline carbonate catalyst is high in carbon oxidizing/activating efficiency at low temperatures. The silica film deposited on an alumina-coated support tube is excellent in selectivity and speed as a hydrogen separating film, and a carbonized polyimide film as a carbon dioxide separating film. For the supercritical phase adsorption/separation of chemicals not to be distilled easily, the NaY-type zeolite functions effectively. Pd/ZrO2 serving as a carbon monoxide conversion catalyst enables the recovery of more MeOH when Pd grains are smaller in diameter.

  13. Computer-Assisted English Learning System Based on Free Conversation by Topic

    Science.gov (United States)

    Choi, Sung-Kwon; Kwon, Oh-Woog; Kim, Young-Kil

    2017-01-01

    This paper aims to describe a computer-assisted English learning system using chatbots and dialogue systems, which allow free conversation outside the topic without limiting the learner's flow of conversation. The evaluation was conducted by 20 experimenters. The performance of the system based on a free conversation by topic was measured by the…

  14. Gas turbine power conversion systems for modular HTGRs. Report of a technical committee meeting

    International Nuclear Information System (INIS)

    2001-08-01

    The Technical Committee Meeting (TCM) on Gas Turbine Power Conversion Systems for Modular HTGRs held in Palo Alto, California, USA was convened by the IAEA on the recommendation of its International Working Group on Gas Cooled Reactors (IWGGCR). The meeting was attended by 27 participants from 9 Member States (Argentina, China, France, Japan, Netherlands, Russian Federation, South Africa, United Kingdom and the United States of America). In addition to presentations on relevant technology development activities in participating Member States, 16 technical papers were presented covering the areas of: Power conversion system design; Power conversion system analysis; and Power conversion system component design. A panel discussion was held on technology issues associated with gas turbine modular HTGR power conversion systems and the potential for international collaboration to address these issues. The purpose of this Technical Committee Meeting was to foster the international exchange of information and perspectives on gas turbine power conversion systems and components for modular HTGRs. The overall objectives were to provide: a current overview of designs under consideration; information on the commercial availability or development status of key components; exchange of information on the issues involved and potential solutions; identification of further development needs for both initial deployment and longer term performance enhancement, and the potential for addressing needs through international collaboration. The following conclusions and recommendations were identified as a result of the discussions at the meeting. International review and collaboration is of interest for China and Japan in the planning and conduct of their test programs: both the HTTR and HTR-10 reactor projects are exploring scale model testing of a gas turbine, with the HTTR project considering a 7 MWt gas heated loop, and HTR-10 a direct or indirect cycle connected to the reactor; the HTR

  15. Photoelectrochemical based direct conversion systems for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Kocha, S.; Peterson, M.; Arent, D. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-10-01

    Photon driven, direct conversion systems consist of a light absorber and a water splitting catalyst as a monolithic system; water is split directly upon illumination. This one-step process eliminates the need to generate electricity externally and subsequently feed it to an electrolyzer. These configurations require only the piping necessary for transport of hydrogen to an external storage system or gas pipeline. This work is focused on multiphoton photoelectrochemical devices for production of hydrogen directly using sunlight and water. Two types of multijunction cells, one consisting of a-Si triple junctions and the other GaInP{sub 2}/GaAs homojunctions, were studied for the photoelectrochemical decomposition of water into hydrogen and oxygen from an aqueous electrolyte solution. To catalyze the water decomposition process, the illuminated surface of the device was modified either by addition of platinum colloids or by coating with ruthenium dioxide. These colloids have been characterized by gel electrophoresis.

  16. Acceleration of the solar-thermal energy development but still some brakes upon photovoltaic conversion

    International Nuclear Information System (INIS)

    Anon.

    2006-01-01

    France shows today the highest growth rate for solar thermal energy with respect to other European countries. This market is structuring and tries to favour quality. A label for systems certification has been presented in January 2007. Photovoltaic conversion has been tied up for a long time by poorly attractive power repurchase tariffs. It benefits now from a propitious framework for its development even if some financial incentive questions relative to the integration of solar panels to buildings remain unanswered. (J.S.)

  17. Designing Energy Conversion Systems for the Next Decade

    Directory of Open Access Journals (Sweden)

    Slobodan N. Vukosavić

    2012-12-01

    Full Text Available Sustainable growth in energy consumption requires transition to clean and green energy sources and energy systems. Environment friendly and renewable energy systems deal with electrical energy and rely on efficient electrical power converters. High power electronics is the key technology to deal with the next generation of electrical energy systems. The door to future breakthroughs in high power electronics is opened by major improvement in semiconductor power devices and their packaging technologies. New materials allow for much higher junction temperatures and higher operating voltages. Most importantly, advanced power semiconductor devices and novel converter topology open the possibility to increase the energy efficiency of power conversion and reduce the amount of heat. Although the waste heat created by high power converters can be put to use by adding on to heating systems, this option is not always available and the conversion losses are mostly wasted. At the same time, wasted heat is a form of pollution that threatens the environment. Another task for high power converters is efficient harvesting of renewable energy sources, such as the wind energy and the sun. Intermittent in nature, they pose a difficult task to power converter topology and controls. Eventually, high power converters are entering power distribution and transmission networks. With their quick reaction, with fast communication between the grid nodes and with advanced controllability of high power converters, a number of innovations can be introduced, facilitating the power system control and allowing for optimizations and loss reduction. Coined smart grid, this solution comprises two key elements, and these are intelligent controls and large static power converters. At virtually no cost, smart grids allow for a better utilization of available resources and it enlarges the stable operating range of the transmission systems. Therefore, it is of interest to review the

  18. Assessment of dynamic energy conversion systems for radioisotope heat sources

    International Nuclear Information System (INIS)

    Thayer, G.R.; Mangeng, C.A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745 0 C, and case III with a BOL source temperature of 945 0 C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of 238 Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass

  19. Development of GT-MGR plant power conversion unit design

    International Nuclear Information System (INIS)

    Kostin, V.I.; Kodochigov, N.G.; Belov, S.E.; Vasyaev, A.V.; Golovko, V.F.; Shenoj, A.

    2007-01-01

    The General Atomic Company (USA) and the Pilot Design Bureau for Machine-Building (Russia) are involved in the efforts to design the GT-MGR modular helium cooled reactor and the energy conversion unit with the direct gas turbine cycle. The reactor capacity is equal to 600 MW, it is cooled by helium under 7 MPa pressure. The energy conversion unit consists of a gas turbine, a recuperator, preliminary and intermediate coolers, a generator. The turbine shaft rotation frequency is equal to 4400 rotation/minute. One analyzed the alternate designs of the energy conversion unit to choose its configuration [ru

  20. Aerojet Energy Conversion Company mobile volume reduction system

    International Nuclear Information System (INIS)

    Smith, K.R.

    1984-01-01

    Over the past few years, rapidly increasing costs for the disposal of low level radioactive waste (LLW) have generated the need for utilities to volume-reduce their LLW prior to shipment and burial. Incineration systems have been selected by several utilities to fulfill this need for maximum volume reduction. Until recently, all of the incineration systems selected by utilities were designed to be housed and operated in a facility erected by the utility. Now, however, lack of capital and rising design/erection costs are causing utilities to reevaluate their plans for purchasing incineration systems to process their LLW. The result is a growing demand for incineration services. Once again, Commonwealth Edison Company (Com-Ed) is leading the industry with an ongoing program to utilize incineration services provided by Aerojet Energy Conversion Company (AECC) for the Dresden Quad Cities, LaSalle, and Zion Nuclear Stations. At the stations, combustible dry active waste and contaminated oil will be processed in a Mobile Volume Reduction System (MVRS) designed and fabricated by AECC. The MVRS is a totally self-contained system consisting of a controlled-air incinerator and a liquid offgas cleanup system. No buildings are required to house the system, and the MVRS achieves volume reduction factors similar to systems currently available for permanent in-plant installation. The result is an option for the utility having the benefits of volume reduction without the capital commitment normally required by the utility

  1. Status of LEU fuel development and conversion of NRU

    International Nuclear Information System (INIS)

    Sears, D.F.; Herbert, L.N.; Vaillancourt, K.D.

    1989-11-01

    The status of the low-enrichment uranium (LEU) fuel development and NRU conversion program at Chalk River Nuclear Laboratories is reviewed. Construction of a new fuel fabrication facility is essentially completed and installation of LEW fuel manufacturing equipment has begun. The irradiation of 31 prototype Al-61 wt% U 3 Si dispersion fuel rods, approximately one third of a full NRU core, is continuing without incident. Recent post-irradiation examination of spent fuel rods revealed that the prototype LEU fuel achieved the design burnup (80 at%) in excellent condition, confirming that the Al-U 3 Si 2 dispersion fuel to complement out Al-U 3 Si capability. Three full-size NRU rods containing Al-U 3 Si 2 dispersion fuel have been fabricated for a qualification irradiation in NRU. Post-irradiation examinations of mini-elements containing Al-U 3 Si 2 fuel revealed that the U 3 Si 2 behaved similarly to U 3 Si 2 fuel revealed that the U 3 Si 2 particles and the aluminum matrix, and fission gas bubbles up to 10 μm in diameter, could be seen in the particles after 60 at% and 80 at% burnup. The mini-elements contained a variety of silicide particle sizes; however, no significant swelling dependence on particle size distribution was observed

  2. Model predictive control of wind energy conversion systems

    CERN Document Server

    Yaramasu, Venkata Narasimha R

    2017-01-01

    The authors provide a comprehensive analysis on the model predictive control of power converters employed in a wide variety of variable-speed wind energy conversion systems (WECS). The contents of this book includes an overview of wind energy system configurations, power converters for variable-speed WECS, digital control techniques, MPC, modeling of power converters and wind generators for MPC design. Other topics include the mapping of continuous-time models to discrete-time models by various exact, approximate, and quasi-exact discretization methods, modeling and control of wind turbine grid-side two-level and multilevel voltage source converters. The authors also focus on the MPC of several power converter configurations for full variable-speed permanent magnet synchronous generator based WECS, squirrel-cage induction generator based WECS, and semi-variable-speed doubly fed induction generator based WECS.

  3. High efficiency heat transport and power conversion system for cascade

    International Nuclear Information System (INIS)

    Maya, I.; Bourque, R.F.; Creedon, R.L.; Schultz, K.R.

    1985-02-01

    The Cascade ICF reactor features a flowing blanket of solid BeO and LiAlO 2 granules with very high temperature capability (up to approx. 2300 K). The authors present here the design of a high temperature granule transport and heat exchange system, and two options for high efficiency power conversion. The centrifugal-throw transport system uses the peripheral speed imparted to the granules by the rotating chamber to effect granule transport and requires no additional equipment. The heat exchanger design is a vacuum heat transfer concept utilizing gravity-induced flow of the granules over ceramic heat exchange surfaces. A reference Brayton power cycle is presented which achieves 55% net efficiency with 1300 K peak helium temperature. A modified Field steam cycle (a hybrid Rankine/Brayton cycle) is presented as an alternate which achieves 56% net efficiency

  4. Modeling power electronics and interfacing energy conversion systems

    CERN Document Server

    Simões, Marcelo Godoy

    2017-01-01

    Discusses the application of mathematical and engineering tools for modeling, simulation and control oriented for energy systems, power electronics and renewable energy. This book builds on the background knowledge of electrical circuits, control of dc/dc converters and inverters, energy conversion and power electronics. The book shows readers how to apply computational methods for multi-domain simulation of energy systems and power electronics engineering problems. Each chapter has a brief introduction on the theoretical background, a description of the problems to be solved, and objectives to be achieved. Block diagrams, electrical circuits, mathematical analysis or computer code are covered. Each chapter concludes with discussions on what should be learned, suggestions for further studies and even some experimental work.

  5. Photovoltaic module with integrated power conversion and interconnection system - the European project PV-MIPS

    OpenAIRE

    Henze, N.; Engler, A.; Zacharias, P.

    2006-01-01

    Within the 6th framework program funded by the European Commission the project PV-MIPS (Photovoltaic Module with Integrated Power Conversion System) was launched in November 2004. Together with eleven European partners from Germany, Austria, Greece and the Netherlands a solar module with integrated in-verter shall be developed that can feed solar electricity directly into the grid. The challenging objective of the project is to reduce the total costs of a PV system. At the same time lifetime ...

  6. On the Development of Fuel-Free Power Supply Sources on Pneumatic Energy Conversion Principles

    Science.gov (United States)

    Son, E. E.; Nikolaev, V. G.; Kudryashov, Yu. I.; Nikolaev, V. V.

    2017-12-01

    The article is devoted to the evaluation of capabilities and problems of creation of fuel-free power supply of isolated and autonomous Russian consumers of low (up to several hundreds kW) power based on the joint use of wind power plants and progressive systems of pneumatic accumulation and conversion of energy. The basic and functional schemes and component structure of the system prototype are developed and proposed, the evaluations of the expected technical and economic indicators of system are presented, and the ways of its further practical implementation are planned.

  7. EnerGis: A geographical information based system for the evaluation of integrated energy conversion systems in urban areas

    International Nuclear Information System (INIS)

    Girardin, Luc; Marechal, Francois; Dubuis, Matthias; Calame-Darbellay, Nicole; Favrat, Daniel

    2010-01-01

    A geographical information system has been developed to model the energy requirements of an urban area. The purpose of the platform is to model with sufficient detail the energy services requirements of a given geographical area in order to allow the evaluation of the integration of advanced integrated energy conversion systems. This tool is used to study the emergence of more efficient cities that realize energy efficiency measures, integrate energy efficient conversion technologies and promote the use of endogenous renewable energy. The model is illustrated with case studies for the energetic planning of the Geneva district (Switzerland).

  8. Automated logic conversion method for plant controller systems

    International Nuclear Information System (INIS)

    Wada, Yutaka; Kobayashi, Yasuhiro; Miyo, Tsunemasa; Okano, Masato.

    1990-01-01

    An automated method is proposed for logic conversion from functional description diagrams to detailed logic schematics by incorporating expertise knowledge in plant controller systems design. The method uses connection data of function elements in the functional description diagram as input, and synthesizes a detailed logic structure by adding elements to the given connection data incrementally, and to generate detailed logic schematics. In logic synthesis, for building up complex synthesis procedures by combining generally-described knowledge, knowledge is applied by groups. The search order of the groups is given by upper-level knowledge. Furthermore, the knowledge is expressed in terms of two classes of rules; one for generating a hypothesis of individual synthesis operations and the other for considering several hypotheses to determine the connection ordering of elements to be added. In the generation of detailed logic schematics, knowledge is used as rules for deriving various kinds of layout conditions on schematics, and rules for generating two-dimensional coordinates of layout objects. Rules in the latter class use layout conditions to predict intersections among layout objects without their coordinates being fixed. The effectiveness of the method with 150 rules was verified by its experimental application to some logic conversions in a real power plant design. Evaluation of the results showed them to be equivalent to those obtained by well qualified designers. (author)

  9. Solid waste information and tracking system server conversion project management plan

    International Nuclear Information System (INIS)

    MAY, D.L.

    1999-01-01

    The Project Management Plan governing the conversion of Solid Waste Information and Tracking System (SWITS) to a client-server architecture. The Solid Waste Information and Tracking System Project Management Plan (PMP) describes the background, planning and management of the SWITS conversion. Requirements and specification documentation needed for the SWITS conversion will be released as supporting documents

  10. 76 FR 55213 - Technical Amendments to Federal Employees' Retirement System; Present Value Conversion Factors...

    Science.gov (United States)

    2011-09-07

    ... Employees' Retirement System; Present Value Conversion Factors for Spouses of Deceased Separated Employees... to read as follows: Appendix A to Subpart C of Part 843--Present Value Conversion Factors for Earlier...

  11. 24 CFR 972.115 - Relationship between required conversions and HOPE VI developments.

    Science.gov (United States)

    2010-04-01

    ... conversions and HOPE VI developments. 972.115 Section 972.115 Housing and Urban Development Regulations... Relationship between required conversions and HOPE VI developments. HUD actions to approve or deny proposed HOPE VI revitalization plans must be consistent with the requirements of this subpart. Developments...

  12. Highly efficient power system based on direct fission fragment energy conversion utilizing magnetic collimation

    International Nuclear Information System (INIS)

    Tsvetkov, Pavel V.; Hart, Ron R.; Parish, Theodore A.

    2003-01-01

    The present study was focused on developing a technologically feasible power system that is based on direct fission fragment energy conversion utilizing magnetic collimation. The new concept is an attempt to combine several advantageous design solutions, which have been proposed for application in both fission and fusion reactors, into one innovative system that can offer exceptional energy conversion efficiency. The analysis takes into consideration a wide range of operational aspects including fission fragment escape from the fuel, collimation, collection, criticality, long-term performance, energy conversion efficiency, heat removal, and safety characteristics. Specific characteristics of the individual system components and the entire system are evaluated. Consistent analysis and evaluation of the technological feasibility of the concept were achieved using state-of-the-art computer codes that allowed realistic and consistent modeling. The calculated energy conversion efficiencies for the presented designs without a thermodynamic cycle and with the heavy water cycle are 52% and 62%, respectively. The analysis indicates that efficiencies up to 90% are potentially achievable. (author)

  13. Process systems engineering issues and applications towards reducing carbon dioxide emissions through conversion technologies

    DEFF Research Database (Denmark)

    Roh, Kosan; Frauzem, Rebecca; Gani, Rafiqul

    2016-01-01

    This paper reviews issues and applications for design of sustainable carbon dioxide conversion processes, specifically through chemical conversion, and the integration of the conversion processes with other systems from a process systems engineering (PSE) view-point. Systematic and computer......-aided methods and tools for reaction network generation, processing route generation, process design/optimization, and sustainability analysis are reviewed with respect to carbon dioxide conversion. Also, the relevant gaps and opportunities are highlighted. In addition, the integration of carbon dioxide...

  14. Pit disassembly and conversion demonstration environmental assessment and research and development activities

    International Nuclear Information System (INIS)

    1998-08-01

    A significant portion of the surplus plutonium is in the form of pits, a nuclear weapons component. Pits are composed of plutonium which is sealed in a metallic shell. These pits would need to be safely disassembled and permanently converted to an unclassified form that would be suitable for long-term disposition and international inspection. To determine the feasibility of an integrated pit disassembly and conversion system, a Pit Disassembly and Conversion Demonstration is proposed to take place at the Los Alamos National Laboratory (LANL). This demonstration would be done in existing buildings and facilities, and would involve the disassembly of up to 250 pits and conversion of the recovered plutonium to plutonium metal ingots and plutonium dioxide. This demonstration also includes the conversion of up to 80 kilograms of clean plutonium metal to plutonium dioxide because, as part of the disposition process, some surplus plutonium metal may be converted to plutonium dioxide in the same facility as the surplus pits. The equipment to be used for the proposed demonstration addressed in this EA would use some parts of the Advanced Recovery and Integrated Extraction System (ARIES) capability, other existing equipment/capacities, plus new equipment that was developed at other sites. In addition, small-scale R and D activities are currently underway as part of the overall surplus plutonium disposition program. These R and D activities are related to pit disassembly and conversion, MOX fuel fabrication, and immobilization (in glass and ceramic forms). They are described in Section 7.0. On May 16, 1997, the Office of Fissile Materials Disposition (MD) notified potentially affected states and tribes that this EA would be prepared in accordance with NEPA. This EA has been prepared to provide sufficient information for DOE to determine whether a Finding of No Significant Impact (FONSI) is warranted or whether an EIS must be prepared

  15. Critical success factors for biomass. Identification/specification of critical success factors in the development and market introduction of biomass conversion systems for the production of electricity and/or heat and/or gaseous/liquid secondary energy carriers

    International Nuclear Information System (INIS)

    Van Ree, R.; Dinkelbach, L.; Van Doorn, J.; Hemmes, K.; Gerlagh, T.; Groenendaal, B.

    2000-06-01

    The Dutch government has set the policy target that in 2020 10% of the total energy consumption has to be provided by means of renewable energy sources. Biomass is expected to play a major role (25-30%) in this future renewable energy based energy supply system. However, it is still unclear if this biomass-based target will be reached. Although studies showed that success or failure of innovations and projects depend on a multitude of scientific, technical, economic and societal variables, a number of questions still remained unanswered. This information often concentrated exclusively on the cost price aspects. This study is conducted to identify the internal and external barriers or constraints other than cost aspects, which are of vital importance to a successful penetration of biomass in the Dutch energy market. Barriers with a decreasing influence on the market introduction of bioenergy in the Netherlands are: short-term contractability of biomass (organic waste streams) for energy purposes, applicable emission and waste policies, and unfamiliarity of bioenergy by the public and government. Barriers that potentially could play an important role on the market introduction of bioenergy in the Netherlands in the near future are: long-term contractability of biomass (organic waste streams and energy crops) for energy purposes, the 'new' emission constraints and their potential negative influence on the implementation of small-scale biomass-based combined-cycle plants, the rivalry of bioenergy with other renewable energy based technologies in a liberalising energy market, the social acceptance of bioenergy, the future European agriculture policy (energy crops), and the current status and development perspectives of biomass-based energy conversion technologies. 66 refs

  16. High efficiency Dual-Cycle Conversion System using Kr-85.

    Science.gov (United States)

    Prelas, Mark A; Tchouaso, Modeste Tchakoua

    2018-04-26

    This paper discusses the use of one of the safest isotopes known isotopes, Kr-85, as a candidate fuel source for deep space missions. This isotope comes from 0.286% of fission events. There is a vast quantity of Kr-85 stored in spent fuel and it is continually being produced by nuclear reactors. In using Kr-85 with a novel Dual Cycle Conversion System (DCCS) it is feasible to boost the system efficiency from 26% to 45% over a single cycle device while only increasing the system mass by less than 1%. The Kr-85 isotope is the ideal fuel for a Photon Intermediate Direct Energy Conversion (PIDEC) system. PIDEC is an excellent choice for the top cycle in a DCCS. In the top cycle, ionization and excitation of the Kr-85:Cl gas mixture (99% Kr and 1% Cl) from beta particles creates KrCl* excimer photons which are efficiently absorbed by diamond photovoltaic cells on the walls of the pressure vessels. The benefit of using the DCCS is that Kr-85 is capable of operating at high temperatures in the primary cycle and the residual heat can then be converted into electrical power in the bottom cycle which uses a Stirling Engine. The design of the DCCS begins with a spherical pressure vessel of radius 13.7 cm with 3.7 cm thick walls and is filled with a Kr-85:Cl gas mixture. The inner wall has diamond photovoltaic cells attached to it and there is a sapphire window between the diamond photovoltaic cells and the Kr-85:Cl gas mixture which shields the photovoltaic cells from beta particles. The DCCS without a gamma ray shield has specific power of 6.49 W/kg. A removable 6 cm thick tungsten shield is used to safely limit the radiation exposure levels of personnel. A shadow shield remains in the payload to protect the radiation sensitive components in the flight package. The estimated specific power of the unoptimized system design in this paper is about 2.33 W/kg. The specific power of an optimized system should be higher. The Kr-85 isotope is relatively safe because it

  17. Influences of Different Land Use Spatial Control Schemes on Farmland Conversion and Urban Development

    Science.gov (United States)

    Zhou, Min; Tan, Shukui; Zhang, Lu

    2015-01-01

    Land use planning is always officially implemented as an effective tool to control urban development and protect farmland. However, its impact on land use change remains untested in China. Using a case study of Hang-Jia-Hu region, the main objective of this paper was to investigate the influence of different land use spatial control schemes on farmland conversion and urban development. Comparisons of farmland conversion and urban development patterns between the urban planning area and the non-urban planning area were characterized by using remote sensing, geographical information systems, and landscape metrics. Results indicated that farmland conversion in the non-urban planning area was more intensive than that in the urban planning area, and that farmland patterns was more fragmented in the non-urban planning area. Built-up land patterns in the non-urban planning area showed a trend of aggregation, while those in the urban planning area had a dual trend of fragmentation and aggregation. Existing built-up areas had less influence on built-up land sprawl in the non-urban planning area than that in the urban planning area. Built-up land sprawl in the form of continuous development in the urban planning area led to farmland conversion; and in the non-urban planning area, built-up land sprawl in the form of leapfrogging development resulted in farmland areal declines and fragmentation. We argued that it is a basic requirement to integrate land use plans in urban and non-urban planning areas for land use planning and management. PMID:25915897

  18. Influences of different land use spatial control schemes on farmland conversion and urban development.

    Science.gov (United States)

    Zhou, Min; Tan, Shukui; Zhang, Lu

    2015-01-01

    Land use planning is always officially implemented as an effective tool to control urban development and protect farmland. However, its impact on land use change remains untested in China. Using a case study of Hang-Jia-Hu region, the main objective of this paper was to investigate the influence of different land use spatial control schemes on farmland conversion and urban development. Comparisons of farmland conversion and urban development patterns between the urban planning area and the non-urban planning area were characterized by using remote sensing, geographical information systems, and landscape metrics. Results indicated that farmland conversion in the non-urban planning area was more intensive than that in the urban planning area, and that farmland patterns was more fragmented in the non-urban planning area. Built-up land patterns in the non-urban planning area showed a trend of aggregation, while those in the urban planning area had a dual trend of fragmentation and aggregation. Existing built-up areas had less influence on built-up land sprawl in the non-urban planning area than that in the urban planning area. Built-up land sprawl in the form of continuous development in the urban planning area led to farmland conversion; and in the non-urban planning area, built-up land sprawl in the form of leapfrogging development resulted in farmland areal declines and fragmentation. We argued that it is a basic requirement to integrate land use plans in urban and non-urban planning areas for land use planning and management.

  19. Progress on PEP-II magnet power conversion system

    International Nuclear Information System (INIS)

    Bellomo, P.; Genova, L.; Jackson, T.; Shimer, D.

    1996-01-01

    The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ''building block'' approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures

  20. Progress on PEP-II magnet power conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Bellomo, P.; Genova, L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Jackson, T. [Lawrence Berkeley National Lab., CA (United States); Shimer, D. [Lawrence Livermore National Lab., CA (United States)

    1996-06-04

    The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ``building block`` approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures.

  1. 5 CFR 9701.231 - Conversion of positions and employees to the DHS classification system.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion of positions and employees to... Provisions § 9701.231 Conversion of positions and employees to the DHS classification system. (a) This... from the GS system, a prevailing rate system, the SL/ST system, or the SES system, as provided in...

  2. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    International Nuclear Information System (INIS)

    Siamidis, John; Mason, Lee

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS O pt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids

  3. The LEU target development and conversion program for the MAPLE reactors and new processing facility

    International Nuclear Information System (INIS)

    Malkoske, G.R.

    2002-01-01

    Historically, the production of molybdenum-99 in the NRU research reactors at Chalk River, Canada has been extracted from reactor targets employing highly enriched uranium (HEU). A reliable supply of HEU metal from the United States used in the manufacture of targets for the NRU research reactor has been a key factor to enable MDS Nordion to develop a secure supply of medical isotopes for the international nuclear medicine community. The molybdenum extraction process from HEU targets provides predictable, consistent yields for our high-volume molybdenum production process. Each link of the isotope supply chain, from isotope production to ultimate use by the physician, has been established using this proven and established method of HEU target irradiation and processing to extract molybdenum-99. To ensure a continued reliable and timely supply of medical isotopes, MDS Nordion is completing the construction of two MAPLE reactors and a New Processing Facility. The design of the MAPLE facilities was based on an established process developed by Atomic Energy of Canada Ltd. (AECL) - extraction of isotopes from HEU target material. However, in concert with the global trend to utilize low enriched uranium (LEU) in research reactors, MDS Nordion has launched a three phase LEU Target Development and Conversion Program for the MAPLE facilities. Phase 1, the Initial Feasibility Study, which identified the technical issues to convert the MAPLE reactor targets from HEU to LEU for large scale commercial production was reported on at the RERTR- 2000 conference. The second phase of the LEU Target Development and Conversion Program was developed with extensive consultation and involvement of experts knowledgeable in target development, process system design, enriched uranium conversion chemistry and commercial scale reactor operations and molybdenum production. This paper will provide an overview of the Phase 2 Conversion Development Program, report on progress to date, and further

  4. Study on thermal electric conversion system for FBR plant. Investigation for effective EVST waste heat recovery system

    International Nuclear Information System (INIS)

    Maekawa, Isamu; Kurata, Chikatoshi

    2004-02-01

    Recently, it has been important to reuse discharged heat energy from present nuclear plant, especially from sodium cooled FBR, which are typical high temperature system, in the view of reduction of environmental burden and improvement of heat efficiency for plant. The thermal electric conversion system can work only the temperature difference and has been applied to the limited fields such as space or military, however, that results show good merits for reliability, maintenance free, and so on. Recently, the development of new thermal electric conversion elements has made remarkable progress. In this study, for the effective utilization of waste heat from Monju', the prototype plant of FBR, we made an investigation of electric power generating system maintaining the cooling faculty by applying the thermal electric conversion system to sodium cooling line of EVST. Using the new type iron based thermal electric conversion elements, which are plentiful, economical and good for environmental harmonization, we have calculated the amount of heat exchange and power generation from sodium cooling line of EVST, and have investigated the module sizing, cost and subject to be settled. The results were , (1)The amount of power generation from sodium cooling line of EVST is smaller about one figure than motive power of sodium cooler fan. However, if Seebeck coefficient and heat conductivity of iron based thermal electric conversion elements shall be improved, power from sodium cooling line shall be able to cover the motive power. (2) The amount of heat released from sodium cooling line after the installation of thermal electric conversion module covers the necessity to maintain the sodium cooling faculty. (3) In case of the installation of module to the sodium cooler, it should be reconstructed because of tube arrangement modification. In case of the installation of module to the sodium connecting line, air ventilation system is needed to suppress the room temperature. (4) As

  5. RSMASS system model development

    International Nuclear Information System (INIS)

    Marshall, A.C.; Gallup, D.R.

    1998-01-01

    RSMASS system mass models have been used for more than a decade to make rapid estimates of space reactor power system masses. This paper reviews the evolution of the RSMASS models and summarizes present capabilities. RSMASS has evolved from a simple model used to make rough estimates of space reactor and shield masses to a versatile space reactor power system model. RSMASS uses unique reactor and shield models that permit rapid mass optimization calculations for a variety of space reactor power and propulsion systems. The RSMASS-D upgrade of the original model includes algorithms for the balance of the power system, a number of reactor and shield modeling improvements, and an automatic mass optimization scheme. The RSMASS-D suite of codes cover a very broad range of reactor and power conversion system options as well as propulsion and bimodal reactor systems. Reactor choices include in-core and ex-core thermionic reactors, liquid metal cooled reactors, particle bed reactors, and prismatic configuration reactors. Power conversion options include thermoelectric, thermionic, Stirling, Brayton, and Rankine approaches. Program output includes all major component masses and dimensions, efficiencies, and a description of the design parameters for a mass optimized system. In the past, RSMASS has been used as an aid to identify and select promising concepts for space power applications. The RSMASS modeling approach has been demonstrated to be a valuable tool for guiding optimization of the power system design; consequently, the model is useful during system design and development as well as during the selection process. An improved in-core thermionic reactor system model RSMASS-T is now under development. The current development of the RSMASS-T code represents the next evolutionary stage of the RSMASS models. RSMASS-T includes many modeling improvements and is planned to be more user-friendly. RSMASS-T will be released as a fully documented, certified code at the end of

  6. Nuclear reactor closed Brayton cycle power conversion system optimization trends for extra-terrestrial applications

    International Nuclear Information System (INIS)

    Ashe, T.L.; Baggenstoss, W.G.; Bons, R.

    1990-01-01

    Extra-terrestrial exploration and development missions of the next century will require reliable, low-mass power generation modules of 100 kW e and more. These modules will be required to support both fixed-base and manned rover/explorer power needs. Low insolation levels at and beyond Mars and long periods of darkness on the moon make solar conversion less desirable for surface missions. For these missions, a closed Brayton cycle energy conversion system coupled with a reactor heat source is a very attractive approach. The authors conducted parametric studies to assess optimized system design trends for nuclear-Brayton systems as a function of operating environment and user requirements. The inherent design flexibility of the closed Brayton cycle energy conversion system permits ready adaptation of the system to future design constraints. This paper describes a dramatic contrast between system designs requiring man-rated shielding. The paper also considers the ramification of using indigenous materials to provide reactor shielding for a fixed-base power source

  7. Methods for locating ground faults and insulation degradation condition in energy conversion systems

    Science.gov (United States)

    Agamy, Mohamed; Elasser, Ahmed; Galbraith, Anthony William; Harfman Todorovic, Maja

    2015-08-11

    Methods for determining a ground fault or insulation degradation condition within energy conversion systems are described. A method for determining a ground fault within an energy conversion system may include, in part, a comparison of baseline waveform of differential current to a waveform of differential current during operation for a plurality of DC current carrying conductors in an energy conversion system. A method for determining insulation degradation within an energy conversion system may include, in part, a comparison of baseline frequency spectra of differential current to a frequency spectra of differential current transient at start-up for a plurality of DC current carrying conductors in an energy conversion system. In one embodiment, the energy conversion system may be a photovoltaic system.

  8. Progress of conversion system from CAD data to MCNP geometry data in Japan

    International Nuclear Information System (INIS)

    Sato, S.; Nashif, H.; Masuda, F.; Morota, H.; Iida, H.; Konno, C.

    2010-01-01

    Automatic conversion systems from CAD data to MCNP geometry input data have been developed to convert the CAD data of the fusion reactor with very complicated structure. So far, two conversion systems (GEOMIT-1 and ARCMCP) have been developed and the third system (GEOMIT-2) is under developing. The void data can be created in these systems. GEOMIT-1 was developed in 2007, but a lot of manual shape splitting work for the CAD data was required to convert the complicated geometry. ARCMCP was developed in 2008. The algorithm has been drastically improved on automatic creation of ambiguous surface in ARCMCP, but it still required a little manual shape splitting work. The latest system, GEOMIT-2, does not require additional commercial software packages, though the previous systems require them. It also has functions of the CAD data healing and the automatic shape splitting. Geometrical errors of CAD data can be automatically revised by the healing function, and complicated geometries can be automatically split into simple geometries by the shape splitting function. Any manual works for CAD data are not required in GEOMIT-2. GEOMIT-2 is very useful for nuclear analyses of fusion reactors.

  9. Cogeneration Technology Alternatives Study (CTAS). Volume 3: Energy conversion system characteristics

    Science.gov (United States)

    1980-01-01

    Six current and thirty-six advanced energy conversion systems were defined and combined with appropriate balance of plant equipment. Twenty-six industrial processes were selected from among the high energy consuming industries to serve as a frame work for the study. Each conversion system was analyzed as a cogenerator with each industrial plant. Fuel consumption, costs, and environmental intrusion were evaluated and compared to corresponding traditional values. The advanced energy conversion technologies indicated reduced fuel consumption, costs, and emissions. Fuel energy savings of 10 to 25 percent were predicted compared to traditional on site furnaces and utility electricity. With the variety of industrial requirements, each advanced technology had attractive applications. Fuel cells indicated the greatest fuel energy savings and emission reductions. Gas turbines and combined cycles indicated high overall annual savings. Steam turbines and gas turbines produced high estimated returns. In some applications, diesels were most efficient. The advanced technologies used coal derived fuels, or coal with advanced fluid bed combustion or on site gasifications. Data and information for both current and advanced energy conversion technology are presented. Schematic and physical descriptions, performance data, equipment cost estimates, and predicted emissions are included. Technical developments which are needed to achieve commercialization in the 1985-2000 period are identified.

  10. International Clean Energy System Using Hydrogen Conversion (WE-NET). subtask 4. Development of hydrogen production technology; Suiso riyo kokusai clean energy system gijutsu (WE-NET). subtask 4. Suiso seizo gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This paper describes development of hydrogen production technology as a part of the WE-NET project. For the solid polymer water electrolysis method higher in efficiency and lower in cost than the previous methods, 5 companies have developed element technologies for improving electrolysis cells and synthesis technologies of hot solid polymer electrolyte based on each proper catalyst electrode production method. In fiscal 1996, the initial study on large-scale systems by middle laboratory cells was made as well as improvement of electrolysis performance by small laboratory cells and endurance tests. Among the previous methods such as a hot press method (bonding of an ion exchange membrane to an electrode), an electroless plating method (preparation of porous surface onto a membrane electrode assembly), a zero gap method (preparation of high-efficiency high-current density cells), and a sintered porous electrode method (carrying of the mixture of catalytic powder and ion exchange resin-dissipated solution onto sintered metallic porous electrode surface), the former two methods were adopted for development of bench-scale cells as effective promising methods. 192 refs., 183 figs., 108 tabs.

  11. Thermophotovoltaic Energy Conversion in Space Nuclear Reactor Power Systems

    National Research Council Canada - National Science Library

    Presby, Andrew L

    2004-01-01

    .... This has potential benefits for space nuclear reactor power systems currently in development. The primary obstacle to space operation of thermophotovoltaic devices appears to be the low heat rejection temperatures which necessitate large radiator areas...

  12. Dynamic Average-Value Modeling of Doubly-Fed Induction Generator Wind Energy Conversion Systems

    Science.gov (United States)

    Shahab, Azin

    In a Doubly-fed Induction Generator (DFIG) wind energy conversion system, the rotor of a wound rotor induction generator is connected to the grid via a partial scale ac/ac power electronic converter which controls the rotor frequency and speed. In this research, detailed models of the DFIG wind energy conversion system with Sinusoidal Pulse-Width Modulation (SPWM) scheme and Optimal Pulse-Width Modulation (OPWM) scheme for the power electronic converter are developed in detail in PSCAD/EMTDC. As the computer simulation using the detailed models tends to be computationally extensive, time consuming and even sometimes not practical in terms of speed, two modified approaches (switching-function modeling and average-value modeling) are proposed to reduce the simulation execution time. The results demonstrate that the two proposed approaches reduce the simulation execution time while the simulation results remain close to those obtained using the detailed model simulation.

  13. Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG

    Science.gov (United States)

    Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya

    2017-10-01

    Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.

  14. Software engineering for the EBR-II data acquisition system conversion

    International Nuclear Information System (INIS)

    Schorzman, W.

    1988-01-01

    The original data acquisition system (DAS) for the Experimental Breeder Reactor II (EBR-II) was placed into service with state-of-the-art computer and peripherals in 1970. Software engineering principles for real-time data acquisition were in their infancy, and the original software design was dictated by limited hardware resources. The functional requirements evolved from creative ways to gather and display data. This abstract concept developed into an invaluable tool for system analysis, data reporting, and as a plant monitor for operations. In this paper the approach is outlined to the software conversion project with the restraints of operational transparency and 6 weeks for final conversion and testing. The outline is then compared with the formal principles of software engineering to show the way that bridge the gap can be bridged between the theoretical and real world by analyzing the work and listing the lessons learned

  15. HYLIFE-II power conversion system design and cost study

    International Nuclear Information System (INIS)

    Hoffman, M.A.

    1990-09-01

    The power conversion system for the HYLIFE-2 fusion power plant has been defined to include the IHX's (intermediate heat exchangers) and everything that support the exchange of energy from the reactor. It is referred to simply as the BOP (balance of plant) in the rest of this report. The above is a convenient division between the reactor equipment and the rest of the fusion power plant since the BOP design and cost then depend only on the specification of the thermal power to the IHX's and the temperature of the primary Flibe coolant into and out of the IHX's, and is almost independent of the details of the reactor design. The main efforts during the first year have been on the definition and thermal-hydraulics of the IHX's, the steam generators and the steam power plant, leading to the definition of a reference BOP with the molten salt, Flibe, as the primary coolant. A summary of the key results in each of these areas is given in this report

  16. Observation of changing of the internal conversion coefficient under Moessbauer effect at magnetic transition in Rh-Fe system

    International Nuclear Information System (INIS)

    Ruskov, T.

    1998-01-01

    The magnetic disorder-order transition in the Rh-Fe alloy is studied by conversion electron Moessbauer spectroscopy. The drastic increase of the area under the Moessbauer spectrum at the transition from the paramagnetic to the magnetic state could be explained by diminishing the internal conversion coefficient. Thus our experimental results directly confirm the theory of the collective effect in the system of radiating developed by Yukalov

  17. A proposed strategy for power optimization of a wind energy conversion system connected to the grid

    International Nuclear Information System (INIS)

    Taraft, S.; Rekioua, D.; Aouzellag, D.; Bacha, S.

    2015-01-01

    Highlights: • Wind energy conversion based doubly fed induction generator controlled by matrix converter. • Operation at both sub and super-synchronous regions is possible with the proposed drive system. • Double the power generated by the DFIG at a twice of speed rated. • Sliding mode control is used to achieve active and reactive power control. - Abstract: Many strategies have been developed in last decade to optimize power extracted from wind energy conversion system where many of them can produce only 30% more than the rated power. With the considered strategy, the generated wind power can reach twice its nominal value using a fast and reliable fully rugged electrical control. Indeed, by employing a suitable control technique where the produced power in super-synchronous mode is derived from both the stator and the rotor. Also, the rotor provided power in this case grows up 100% comparing to stator rated power. However, this solution permits to maintain the wind energy conversion system operation in its stable area. The considered system consists of a double fed induction generator whose stator is connected directly to the grid and its rotor is supplied by matrix converter. In this paper, the sliding mode approach to achieve active and reactive power control is used. This latter is combined with de Perturbation and Observation Maximum Power Point Tracking used in the second operation zone. The obtained simulations results are assessed and carried out using Matlab/Simulink package and show the performance and the effectiveness of the proposed control

  18. Near-infrared (NIR) optogenetics using up-conversion system

    Science.gov (United States)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Yawo, Hiromu

    2015-03-01

    Non-invasive remote control technologies designed to manipulate neural functions for a comprehensive and quantitative understanding of the neuronal network in the brain as well as for the therapy of neurological disorders have long been awaited. Recently, it has become possible to optically manipulate the neuronal activity using biological photo-reactive molecules such as channelrhodopsin-2 (ChR2). However, ChR2 and its relatives are mostly reactive to visible light which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light penetrates deep into the tissues because biological systems are almost transparent to light within this so-called `imaging window'. Here we used lanthanide nanoparticles (LNPs), which are composed of rare-earth elements, as luminous bodies to activate channelrhodopsins (ChRs) since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Neuron-glioma-hybrid ND-7/23 cells were cultured with LNP(NaYF4:Sc/Yb/Er) particles (peak emission, 543 nm) and transfected to express C1V1 (peak absorbance, 539 nm), a chimera of ChR1 and VChR1. The photocurrents were generated in response to NIR laser light (976 nm) to a level comparable to that evoked by a filtered Hg lamp (530-550 nm). NIR light pulses also evoked action potentials in the cultured neurons that expressed C1V1. It is suggested that the green luminescent light emitted from LNPs effectively activated C1V1 to generate the photocurrent. With the optimization of LNPs, acceptor photo-reactive biomolecules and optics, this system could be applied to non-invasively actuate neurons deep in the brain.

  19. Ultra-capacitors in power conversion systems analysis, modeling and design in theory and practice

    CERN Document Server

    Grbovic, Petar J

    2014-01-01

    Divided into five parts, this book is focused on ultra-capacitors and their applications in power conversion systems. It discusses ultra-capacitor analysis, modelling and module design from a macroscopic (application) perspective. It also describes power conversion applications, interface dc-dc converter design and entire conversion system design. Part One covers the background of energy storage technologies, with particular attention on state-of-the-art ultra-capacitor energy storage technologies. In Chapter four of this part, power conversion systems with integrated energy storage is discus

  20. Developing a safety report for an existing conversion facility

    International Nuclear Information System (INIS)

    Carisse, Hess

    2013-01-01

    A review of the process used to meet the regulatory requirements for a Safety Report at an existing conversion facility is described. This paper will cover the establishment of the regulatory criteria, selection of appropriate methodologies, identification of events and modeling of credible events. Once established there is on-going maintenance to deal with design changes and the need for periodic reviews will also be discussed. Challenges in dealing with the various phases, including incorporation of historical licensing documents, and lessons learned are presented. Of specific interest is the failure of the selected methodology to deal with infrastructure issues. One aspect of lessons learned that will be explored is the lack of an available mechanism for sharing information with similar fuel cycle facilities which is compounded by the fact that there are a small number of fuel cycle facilities compared to nuclear power plants. Possible approaches to dealing with this issue are also discussed. (authors)

  1. Development of DKB ETL module in case of data conversion

    Science.gov (United States)

    Kaida, A. Y.; Golosova, M. V.; Grigorieva, M. A.; Gubin, M. Y.

    2018-05-01

    Modern scientific experiments involve the producing of huge volumes of data that requires new approaches in data processing and storage. These data themselves, as well as their processing and storage, are accompanied by a valuable amount of additional information, called metadata, distributed over multiple informational systems and repositories, and having a complicated, heterogeneous structure. Gathering these metadata for experiments in the field of high energy nuclear physics (HENP) is a complex issue, requiring the quest for solutions outside the box. One of the tasks is to integrate metadata from different repositories into some kind of a central storage. During the integration process, metadata taken from original source repositories go through several processing steps: metadata aggregation, transformation according to the current data model and loading it to the general storage in a standardized form. The R&D project of ATLAS experiment on LHC, Data Knowledge Base, is aimed to provide fast and easy access to significant information about LHC experiments for the scientific community. The data integration subsystem, being developed for the DKB project, can be represented as a number of particular pipelines, arranging data flow from data sources to the main DKB storage. The data transformation process, represented by a single pipeline, can be considered as a number of successive data transformation steps, where each step is implemented as an individual program module. This article outlines the specifics of program modules, used in the dataflow, and describes one of the modules developed and integrated into the data integration subsystem of DKB.

  2. Biomass-fuelled PEMFC systems: Evaluation of two conversion paths relevant for different raw materials

    International Nuclear Information System (INIS)

    Guan, Tingting; Chutichai, Bhawasut; Alvfors, Per; Arpornwichanop, Amornchai

    2015-01-01

    Highlights: • Anaerobic digestion and gasification are viable biomass conversion technologies. • GF-PEMFC system yields a 20% electric efficiency and 57% thermal efficiency. • AD-PEMFC system has a 9% electric efficiency and 13% thermal efficiency. • AD-PEMFC system has an efficient land-use. • GF-PEMFC system has a high CO_2 emissions offset factor. - Abstract: Biomass-fuelled polymer electrolyte membrane fuel cells (PEMFCs) offer a solution for replacing fossil fuel with hydrogen production. This paper uses simulation methods for investigating biomass-fuelled PEMFCs for different raw materials and conversion paths. For liquid and solid biomass, anaerobic digestion (AD) and gasification (GF), respectively, are relatively viable and developed conversion technologies. Therefore, the AD-PEMFC system and the GF-PEMFC system are simulated for residential applications in order to evaluate the performance of the biomass-fuelled PEMFC systems. The results of the evaluation show that renewable hydrogen-rich gas from manure or forest residues is usable for the PEMFCs and makes the fuel cell stack work in a stable manner. For 100 kWe generation, the GF-PEMFC system yields an excellent technical performance with a 20% electric efficiency and 57% thermal efficiency, whereas the AD-PEMFC system only has an 9% electric efficiency and 13% thermal efficiency due to the low efficiency of the anaerobic digester (AD) and the high internal heat consumption of the AD and the steam reformer (SR). Additionally, in this study, the environmental performances of the AD-PEMFC and the GF-PEMFC in terms of CO_2 emission offset and land-use efficiency are discussed.

  3. Theoretical analysis of a wind heating conversion and long distance transmission system

    International Nuclear Information System (INIS)

    Cheng, Wen-Long; Han, Bing-Chuan; Nian, Yong-Le; Han, Bing-Bing

    2017-01-01

    Highlights: • A novel long distance wind power heating system was proposed. • Heat losses could be reduced effectively due to latent heat transmission. • Power consumption and cost would drop greatly compared to hot water convey system. • The maximum transmission distance is 10 times that of conventional system. - Abstract: As a clean and renewable energy, wind power gets a rapid growth in recent years. With the increasing proportion of wind power generation, the fluctuation and intermittency of wind energy impedes the safe and stable operation of national power grids, which causes wind curtailment and energy waste, hindering further development of wind power industry in China. To solve this problem, wind heating conversion was proposed. However, long distance transmission between wind fields and residential areas for thermal energy is an urgent issue for wind heating. This paper presents a novel wind heating conversion and long distance transmission system. A simple device was utilized for wind heating conversion in the present system, then thermal energy was transported to heat demand site through latent heat transmission of the working fluids. A model of the novel system was built and thermodynamics analysis showed that maximum transmission distance of the novel system could extended to 240 km, 9.6 times of that of typical hot water transmission system. And the novel system also could cut down the cost by greatly reducing pump work and pipe diameter. In addition, efficiency and circulation ratio was almost unchanged while wind power density increased from 350 W/m 2 to 650 W/m 2 .

  4. Construction of a system for up-conversion detection in vitroceramics doped with rare earths

    International Nuclear Information System (INIS)

    Santa Cruz, P.A.; Azevedo, W.M. de; Sa, G.F. de

    1983-01-01

    A system capable of detecting up-conversion processes by energy transference or cooperative luminescence was developed. Pulverized vitroceramic samples containing PbF 2 and GeO 2 , doped with Yb 2 O 3 as sensitizer and Tm 2 O 3 or Er 2 O 3 as activator, were used. A diagram of the detection system, as well as graphs showing the variation of the emission intensity of these doped vitroceramics as a function of excitation intensity (970 mn), are presented. (C.L.B.) [pt

  5. Protective coatings on structural materials for energy conversion systems

    International Nuclear Information System (INIS)

    John, J.T.; De, P.K.; Srinivasa, R.S.

    2000-01-01

    Full text: Structural Materials and Components used in coal fired energy conversion systems, crude oil refineries and coal gasification plants are subjected to degradation due to oxidation, sulfidation, carbonization and halogenation. Suitable protective coatings can significantly enhance their life. Protective coatings work by forming a highly stable, self-healing and slow growing protective scale at the operating temperatures. These scales act as barriers between the corrosive environment and the alloy and prevent degradation of the substitute. Three types of scales that provide such protection are based on Al 2 O 3 , Cr 2 O 3 and SiO 2 . Aluminide coatings are major alumina forming protecting coatings, applied on nickel, cobalt and iron base alloys. Aluminide coatings are prepared by enriching the surface of a component by aluminum. In this paper the formation of aluminide coatings of nickel, IN738, Alloy 800, Zircaloy-2 and pure iron by chemical vapor deposition has been described. In this technique, Aluminum chloride vapors from bath kept at 353-373 K are carried in a stream of hydrogen gas into a Hot Walled CVD chamber kept at 1173-1373 K. The AlCl 3 vapors were allowed to react with pure aluminum whereby aluminum sub-chlorides like AlCl and AlCl 2 are produced which deposit aluminum on the substrates. At the high temperature of the deposition, aluminum diffuses into the substrate and forms the aluminide coating. The process can be represented by the reaction Al (i) + AlCl 3(g) AlCl 2(s) + AlCl 2 (g) . XRD and optical microscopic studies have characterized the coatings. On pure nickel and Alloy 800 the coating consists of Ni 2 Al 3 and NiAl respectively. On pure iron the coatings consisted of FeAl. On Zircaloy-2, ZrAl 2 was also detected. The CVD coating process, XRD and optical microscopy data will be discussed further

  6. Analog-to-digital conversion of spectrometric data in information-control systems of activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mamonov, E I

    1972-01-01

    Analog-digital conversion (ADC) techniques in nuclear radiation spectrometer channels is a most important link of information control systems in activation analysis. For the development of the ADC of spectrometer channels logico-structural methods of increasing the capacity, procedures for boosting frequency modes and improving the accuracy are promising. Procedures are suggested for increasing the ADC capacity. Insufficient stability and noticeable non-linearity of the spectrometer channel can be corrected at the information processing stage if their regularities are known. Capacity limitations make the development of ADC featuring high stability, capacity and linearity quite urgent.

  7. Development of a DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

    CERN Document Server

    Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Preuten, Marius; Max Rauch; Rittich, David Michael; Sammet, Jan Domenik; Wlochal, Michael

    2014-01-01

    A novel powering scheme based on the DC-DC conversion technique will be exploited to power the CMS Phase-1 pixel detector. DC-DC buck converters for the CMS pixel project have been developed, based on the AMIS5 ASIC designed by CERN. The powering system of the Phase-1 pixel detector is described and the performance of the converter prototypes is detailed, including power efficiency, stability of the output voltage, shielding, and thermal management. Results from a test of the magnetic field tolerance of the DC-DC converters are reported. System tests with pixel modules using many components of the future pixel barrel system are summarized. Finally first impressions from a pre-series of 200 DC-DC converters are presented.

  8. Chart of conversion factors: From English to metric system and metric to English system

    Science.gov (United States)

    ,

    1976-01-01

    The conversion factors in the following tables are for conversion of our customary (English) units of measurement to SI*units, and for convenience, reciprocals are shown for converting SI units back to the English system. The first table contains rule-of-thumb figures, useful for "getting the feel" of SI units or mental estimation. The succeeding tables contain factors accurate to 3 or more significant figures. Please refer to known reference volumes for additional accuracy, as well as for factors dealing with other scientific notation involving SI units.

  9. Integrated bioenergy conversion concepts for small scale gasification power systems

    Science.gov (United States)

    Aldas, Rizaldo Elauria

    microorganisms used to deal with tars are selected and pre-conditioned to the tar environment. Overall, the results provided a basis for operational and design strategy for a combined gasification system but further study is recommended such as determination of the impacts in terms of emissions, power, efficiency and costs associated with the use of producer gas-enriched biogas taking advantage of hydrogen enrichment to reduce NOx and other pollutants in reciprocating engines and other energy conversion systems.

  10. Geo-spatial multi-criteria analysis for wave energy conversion system deployment

    Energy Technology Data Exchange (ETDEWEB)

    Nobre, Ana; Pacheco, Miguel [Data Centre, Instituto Hidrografico, Portuguese Navy, Rua das Trinas 49, 1249-093 Lisboa (Portugal); Jorge, Raquel; Lopes, M.F.P.; Gato, L.M.C. [IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, Avenida Rovisco Pais 1, 1049-001, Lisboa (Portugal)

    2009-01-15

    The growing requirements for renewable energy production lead to the development of a new series of systems, including wave energy conversion systems. Due to their sensitivity and the impact of the aggressive marine environment, the selection of the most adequate location for these systems is a major and very important task. Several factors, such as technological limitations, environmental conditions, administrative and logistic conditions, have to be taken into account in order to support the decision for best location. This paper describes a geo-spatial multi-criteria analysis methodology, based on geographic information systems technology, for identification of the best location to deploy a wave energy farm. This methodology is not conversion system dependent and therefore can be easily customized for different systems and implementation conditions. Selection factors can include, for example, ocean depth, sea bottom type, existing underwater cables, marine protected areas, ports location, shoreline, power grid location, military exercise areas, climatology of wave significant height, period and power. A case study demonstrating this methodology is presented, for an area offshore the Portuguese southwest coast. The system output allows a clear differential identification of the best spots for implementing a wave energy farm. It is not just a simple Boolean result showing valid and invalid locations, but a layer with a valued suitability for farm deployment. (author)

  11. Consideration of ultra-high temperature nuclear heat sources for MHD conversion systems

    International Nuclear Information System (INIS)

    Holman, R.R.; Tobin, J.M.; Young, W.E.

    1975-01-01

    The nuclear technology reactors developed and tested in the Nuclear Engine Rocket Vehicle Application (NERVA) program operated with fuel exit gas temperatures in excess of 2600 K. This experience provided a significant ultra-high temperature technology base and design insight for commercial power applications. Design approaches to accommodate fission product retention and other key prevailing requirements are examined in view of the basic overriding functional requirements, and some interesting reconsiderations are suggested. Predicted overall system performance potentials for a 2000 K MHD conversion system and reactor parameter requirements are compared and related to existing technology status. Needed verification and development efforts are suggested. A reconsideration of basic design approaches is suggested that could open the door for immediate development of ultrahigh temperature nuclear heat sources for advanced energy systems

  12. Development of bioenergy conversion alternatives for climate change mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Derkyi, Nana S.A.; Sekyere, Daniel [CSIR-FORIG, Kwame Nkrumah University of Science and Technology KNUST Box 63 (Ghana); Okyere, Philip Y. [Electrical Engineering Department, Kwame Nkrumah University of Science and Technology KNUST (Ghana); Darkwa, Nicholas A. [FRNR, Kwame Nkrumah University of Science and Technology KNUST (Ghana); Nketiah, Samuel K. [TROPENBOS International (Ghana)

    2011-07-01

    Traditional charcoal production, firewood sourcing and over-dependence on the national grid for electricity are associated with high greenhouse gas emissions relative to other common energy options. However, there have been few attempts to analyze the potential of cogeneration and briquetting as favourable energy options for climate change mitigation. The possibility of utilizing abundant wood residues to produce energy for domestic and industrial application through co-generation and sawdust briquetting was assessed. Annual residues generated in the three mills studied ranged from 19,230 m3 to 32,610 m3. Annual output of semi-carbonized and carbonized sawdust briquette from the briquette factory studied was 1400 tonnes. Heating values of the wood species ranged from 8.2 to 20.3 MJ/kg. Power requirements for the mills, necessary for sizing co-generation units were derived from their monthly electricity bills. Power ratings for co-generation units were specified between 400 kWe to 2000 kWe with heat to power ratios of 19 to 21. The energy generated could be used to produce electrical power and reduce dependency on the national grid. Conversion of sawdust in the briquette factory potentially contributes a saving of 5,600 tonnes of trees/year that would have been cut from the forest. Thus, adoption of co-generation and sawdust briquetting nationwide could be of immense benefit to the country in terms of climate change mitigation.

  13. Speed-sensorless control strategy for multi-phase induction generator in wind energy conversion systems

    Directory of Open Access Journals (Sweden)

    Dumnić Boris P.

    2016-01-01

    Full Text Available Renewable energy sources, especially wind energy conversion systems (WECS, exhibit constant growth. Increase in power and installed capacity led to advances in WECS topologies. Multi-phase approach presents a new development direction, with several key advantages over three-phase systems. Paired with a sensorless control strategy, multi-phase machines are expected to take primacy over standard solutions. This paper presents speed sensorless vector control of an asymmetrical six-phase induction generator based on a model reference adaptive system (MRAS. Suggested topology and developed control algorithm show that sensorless control can yield appropriate dynamic characteristics for the use in WECS with increase in reliability and robustness. [Projekat Ministarstva nauke Republike Srbije, br. III 042004: Smart Electricity Distribution Grids Based on Distribution Management System and Distributed Generation

  14. Module-level DC/DC conversion for photovotaic systems : the delta-conversion concept

    NARCIS (Netherlands)

    Bergveld, H.J.; Büthker, D.; Castello, C.; Doorn, T.S.; Jong, de A.; van Otten, R.; Waal, de K.

    2013-01-01

    Photovoltaic (PV) systems are increasingly used to generate electrical energy from solar irradiation incident on PV modules. PV modules are formed by placing many PV cells in series. The PV system is then formed by placing a number of PV modules in series in a string. In practical cases, differences

  15. Online optimization of a multi-conversion-level DC home microgrid for system efficiency enhancement

    DEFF Research Database (Denmark)

    Boscaino, V.; Guerrero, J. M.; Ciornei, I.

    2017-01-01

    stages, three paralleled DC/DC converters are implemented. A Genetic Algorithm performs the on-line optimization of the DC network’s global efficiency, generating the optimal current sharing ratios of the concurrent power converters. The overall DC/DC conversion system including the optimization section......In this paper, an on-line management system for the optimal efficiency operation of a multi-bus DC home distribution system is proposed. The operation of the system is discussed with reference to a distribution system with two conversion stages and three voltage levels. In each of the conversion...

  16. On Teacher Career Development: A Conversation with Phillip Schlechty.

    Science.gov (United States)

    Brandt, Ron

    1985-01-01

    Briefly discusses Phillip Schlechty's view on teacher career development with university cooperation, needs for systematic faculty development, appropriate administrator roles, encouragement of professionalism, the use of differentiated staffing patterns, and appropriate attitudes toward reform. (PGD)

  17. Biomass Feedstock and Conversion Supply System Design and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, Jacob J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Roni, Mohammad S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lamers, Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cafferty, Kara G. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    Idaho National Laboratory (INL) supports the U.S. Department of Energy’s bioenergy research program. As part of the research program INL investigates the feedstock logistics economics and sustainability of these fuels. A series of reports were published between 2000 and 2013 to demonstrate the feedstock logistics cost. Those reports were tailored to specific feedstock and conversion process. Although those reports are different in terms of conversion, some of the process in the feedstock logistic are same for each conversion process. As a result, each report has similar information. A single report can be designed that could bring all commonality occurred in the feedstock logistics process while discussing the feedstock logistics cost for different conversion process. Therefore, this report is designed in such a way that it can capture different feedstock logistics cost while eliminating the need of writing a conversion specific design report. Previous work established the current costs based on conventional equipment and processes. The 2012 programmatic target was to demonstrate a delivered biomass logistics cost of $55/dry ton for woody biomass delivered to fast pyrolysis conversion facility. The goal was achieved by applying field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model. The goal of the 2017 Design Case is to enable expansion of biofuels production beyond highly productive resource areas by breaking the reliance of cost-competitive biofuel production on a single, low-cost feedstock. The 2017 programmatic target is to supply feedstock to the conversion facility that meets the in-feed conversion process quality specifications at a total logistics cost of $80/dry T. The $80/dry T. target encompasses total delivered feedstock cost, including both grower payment and logistics costs, while meeting all conversion in-feed quality targets

  18. Application of Circuit Model for Photovoltaic Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Natarajan Pandiarajan

    2012-01-01

    Full Text Available Circuit model of photovoltaic (PV module is presented in this paper that can be used as a common platform by material scientists and power electronic circuit designers to develop better PV power plant. Detailed modeling procedure for the circuit model with numerical dimensions is presented using power system blockset of MATLAB/Simulink. The developed model is integrated with DC-DC boost converter with closed-loop control of maximum power point tracking (MPPT algorithm. Simulation results are validated with the experimental setup.

  19. Analysis of gas turbine systems for sustainable energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Anheden, Marie

    2000-02-01

    Increased energy demands and fear of global warming due to the emission of greenhouse gases call for development of new efficient power generation systems with low or no carbon dioxide (CO{sub 2}) emissions. In this thesis, two different gas turbine power generation systems, which are designed with these issues in mind, are theoretically investigated and analyzed. In the first gas turbine system, the fuel is combusted using a metal oxide as an oxidant instead of oxygen in the air. This process is known as Chemical Looping Combustion (CLC). CLC is claimed to decrease combustion exergy destruction and increase the power generation efficiency. Another advantage is the possibility to separate CO{sub 2} without a costly and energy demanding gas separation process. The system analysis presented includes computer-based simulations of CLC gas turbine systems with different metal oxides as oxygen carriers and different fuels. An exergy analysis comparing the exergy destruction of the gas turbine system with CLC and conventional combustion is also presented. The results show that it is theoretically possible to increase the power generation efficiency of a simple gas turbine system by introducing CLC. A combined gas/steam turbine cycle system with CLC is, however, estimated to reach a similar efficiency as the conventional combined cycle system. If the benefit of easy and energy-efficient CO{sub 2} separation is accounted for, a CLC combined cycle system has a potential to be favorable compared to a combined cycle system with CO{sub 2} separation. In the second investigation, a solid, CO{sub 2}-neutral biomass fuel is used in a small-scale externally fired gas turbine system for cogeneration of power and district heating. Both open and closed gas turbines with different working fluids are simulated and analyzed regarding thermodynamic performance, equipment size, and economics. The results show that it is possible to reach high power generation efficiency and total (power

  20. Energy harvesting solar, wind, and ocean energy conversion systems

    CERN Document Server

    Khaligh, Alireza

    2009-01-01

    Also called energy scavenging, energy harvesting captures, stores, and uses ""clean"" energy sources by employing interfaces, storage devices, and other units. Unlike conventional electric power generation systems, renewable energy harvesting does not use fossil fuels and the generation units can be decentralized, thereby significantly reducing transmission and distribution losses. But advanced technical methods must be developed to increase the efficiency of devices in harvesting energy from environmentally friendly, ""green"" resources and converting them into electrical energy.Recognizing t

  1. White Pine Co. Public School System Biomass Conversion Heating Project

    Energy Technology Data Exchange (ETDEWEB)

    Paul Johnson

    2005-11-01

    The White Pine County School District and the Nevada Division of Forestry agreed to develop a pilot project for Nevada using wood chips to heat the David E. Norman Elementary School in Ely, Nevada. Consideration of the project was triggered by a ''Fuels for Schools'' grant that was brought to the attention of the School District. The biomass project that was part of a district-wide energy retrofit, called for the installation of a biomass heating system for the school, while the current fuel oil system remained as back-up. Woody biomass from forest fuel reduction programs will be the main source of fuel. The heating system as planned and completed consists of a biomass steam boiler, storage facility, and an area for unloading and handling equipment necessary to deliver and load fuel. This was the first project of it's kind in Nevada. The purpose of the DOE funded project was to accomplish the following goals: (1) Fuel Efficiency: Purchase and install a fuel efficient biomass heating system. (2) Demonstration Project: Demonstrate the project and gather data to assist with further research and development of biomass technology; and (3) Education: Educate the White Pine community and others about biomass and other non-fossil fuels.

  2. Supercritical CO2 Brayton Cycle Energy Conversion System Coupled with SFR

    International Nuclear Information System (INIS)

    Cha, Jae Eun; Kim, S. O.; Seong, S. H.; Eoh, J. H.; Lee, T. H.; Choi, S. K.; Han, J. W.; Bae, S. W.

    2008-12-01

    This report contains the description of the S-CO 2 Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system. For a system development, a computer code was developed to calculate heat balance of normal operation condition. Based on the computer code, the S-CO 2 Brayton cycle energy conversion system was constructed for the KALIMER-600. Computer codes were developed to analysis for the S-CO 2 turbomachinery. Based on the design codes, the design parameters were prepared to configure the KALIMER-600 S-CO 2 turbomachinery models. A one-dimensional analysis computer code was developed to evaluate the performance of the previous PCHE heat exchangers and a design data for the typical type PCHE was produced. In parallel with the PCHE-type heat exchanger design, an airfoil shape fin PCHE heat exchanger was newly designed. The new design concept was evaluated by three-dimensional CFD analyses. Possible control schemes for power control in the KALIMER-600 S-CO 2 Brayton cycle were investigated by using the MARS code. The MMS-LMR code was also developed to analyze the transient phenomena in a SFR with a supercritical CO 2 Brayton cycle to develop the control logic. Simple power reduction and recovery event was selected and analyzed for the transient calculation. For the evaluation of Na-CO 2 boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO 2 gas. The long term behavior of a Na-CO 2 boundary failure event and its consequences which lead to a system pressure transient were evaluated

  3. 120-keV beam direct conversion system for TFTR injectors

    International Nuclear Information System (INIS)

    Hamilton, G.W.

    1976-01-01

    Several practical motivations exist for the development of beam direct conversion systems that are compatible with the injection systems of large experiments such as the Tokamak Fusion Test Reactor (TFTR). We present a preliminary design in which we analyze the most acute problems involved in scaling up existing designs and apparatus to fulfill TFTR requirements. Some of the questions addressed are the requirements for electron suppression, gas pumping, compactness, and power densities. A new idea is presented that allows for the handling of higher beam power. The gross savings in the capital cost of injector power supplies for the TFTR will be about $7.2 million, but the net savings will be somewhat less than this. This preliminary design has not yet revealed fundamental limitations with respect to the development of beam energy-recovery systems operating at high levels of current, voltage, and power densities

  4. Thermodynamic analysis of energy conversion and transfer in hybrid system consisting of wind turbine and advanced adiabatic compressed air energy storage

    International Nuclear Information System (INIS)

    Zhang, Yuan; Yang, Ke; Li, Xuemei; Xu, Jianzhong

    2014-01-01

    A simulation model consisting of wind speed, wind turbine and AA-CAES (advanced adiabatic compressed air energy storage) system is developed in this paper, and thermodynamic analysis on energy conversion and transfer in hybrid system is carried out. The impacts of stable wind speed and unstable wind speed on the hybrid system are analyzed and compared from the viewpoint of energy conversion and system efficiency. Besides, energy conversion relationship between wind turbine and AA-CAES system is investigated on the basis of process analysis. The results show that there are several different forms of energy in hybrid system, which have distinct conversion relationship. As to wind turbine, power coefficient determines wind energy utilization efficiency, and in AA-CAES system, it is compressor efficiency that mainly affects energy conversion efficiencies of other components. The strength and fluctuation of wind speed have a direct impact on energy conversion efficiencies of components of hybrid system, and within proper wind speed scope, the maximum of system efficiency could be expected. - Highlights: • A hybrid system consisting of wind, wind turbine and AA-CAES system is established. • Energy conversion in hybrid system with stable and unstable wind speed is analyzed. • Maximum efficiency of hybrid system can be reached within proper wind speed scope. • Thermal energy change in hybrid system is more sensitive to wind speed change. • Compressor efficiency can affect other efficiencies in AA-CAES system

  5. Foreign Language Tutoring in Oral Conversations Using Spoken Dialog Systems

    Science.gov (United States)

    Lee, Sungjin; Noh, Hyungjong; Lee, Jonghoon; Lee, Kyusong; Lee, Gary Geunbae

    Although there have been enormous investments into English education all around the world, not many differences have been made to change the English instruction style. Considering the shortcomings for the current teaching-learning methodology, we have been investigating advanced computer-assisted language learning (CALL) systems. This paper aims at summarizing a set of POSTECH approaches including theories, technologies, systems, and field studies and providing relevant pointers. On top of the state-of-the-art technologies of spoken dialog system, a variety of adaptations have been applied to overcome some problems caused by numerous errors and variations naturally produced by non-native speakers. Furthermore, a number of methods have been developed for generating educational feedback that help learners develop to be proficient. Integrating these efforts resulted in intelligent educational robots — Mero and Engkey — and virtual 3D language learning games, Pomy. To verify the effects of our approaches on students' communicative abilities, we have conducted a field study at an elementary school in Korea. The results showed that our CALL approaches can be enjoyable and fruitful activities for students. Although the results of this study bring us a step closer to understanding computer-based education, more studies are needed to consolidate the findings.

  6. Evaluation of maximum power point tracking in hydrokinetic energy conversion systems

    Directory of Open Access Journals (Sweden)

    Jahangir Khan

    2015-11-01

    Full Text Available Maximum power point tracking is a mature control issue for wind, solar and other systems. On the other hand, being a relatively new technology, detailed discussion on power tracking of hydrokinetic energy conversion systems are generally not available. Prior to developing sophisticated control schemes for use in hydrokinetic systems, existing know-how in wind or solar technologies can be explored. In this study, a comparative evaluation of three generic classes of maximum power point scheme is carried out. These schemes are (a tip speed ratio control, (b power signal feedback control, and (c hill climbing search control. In addition, a novel concept for maximum power point tracking: namely, extremum seeking control is introduced. Detailed and validated system models are used in a simulation environment. Potential advantages and drawbacks of each of these schemes are summarised.

  7. The closed Brayton cycle: An energy conversion system for near-term military space missions

    Science.gov (United States)

    Davis, Keith A.

    The Particle Bed Reactor (PBR)-closed Brayton cycle (CBC) provides a 5 to 30 kWe class nuclear power system for surveillance and communication missions during the 1990s and will scale to 100 kWe and beyond for other space missions. The PBR-CBC is technically feasible and within the existing state of the art. The PBR-CBC system is flexible, scaleable, and offers development economy. The ability to operate over a wide power range promotes commonality between missions with similar but not identical power spectra. The PBR-CBC system mass is very competitive with rival nuclear dynamic and static power conversion and systems. The PBR-CBC provides growth potential for the future with even lower specific masses.

  8. Conceptual design of a FGM thermoelectric energy conversion system for high temperature heat source. 1. Design of thermoelectric energy conversion unit

    International Nuclear Information System (INIS)

    Kambe, Mitsuru; Teraki, Junichi; Hirano, Toru.

    1996-01-01

    Thermoelectric (TE) power conversion system has been focused as a candidate of direct energy conversion systems for high temperature heat source to meet the various power requirements in next century. A concept of energy conversion unit by using TE cell elements combined with FGM compliant pads has been presented to achieve high thermal energy density as well as high energy conversion efficiency. An energy conversion unit consists of 8 couples of P-N cell elements sandwiched between two FGM compliant pads. Performance analysis revealed that the power generated by this unit was 11 watts which is nearly ten times as much as conventional unit of the same size. Energy conversion efficiency of 12% was expected based on the assumption of ZT = 1. All the member of compliant pads as well as TE cells could be bonded together to avoid thermal resistance. (author)

  9. Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems. Final report

    International Nuclear Information System (INIS)

    Harty, R.B.; Durand, R.E.

    1993-03-01

    An integration study was performed by Rocketdyne under contract to NASA-LeRC. The study was concerned with coupling an SP-0100 reactor to either a Brayton or Stirling power conversion system. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power conversion redundancy. This study resulted in selecting three operating engines and one stand-by unit. Integration design studies indicated that either the Brayton or Stirling power conversion systems could be integrated with the PS-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to off-set the Stirling integration advantage. From a performance consideration, the Brayton had a 9 percent mass advantage, and the Stirling had a 50 percent radiator advantage

  10. Investigation of modeling and simulation on a PWR power conversion system with RELAP5

    International Nuclear Information System (INIS)

    Rui Gao; Yang Yanhua; Lin Meng; Yuan Minghao; Xie Zhengrui

    2007-01-01

    Based on the power conversion system of nuclear and conventional islands of Dayabay nuclear power station, this paper models the thermal-hydraulic systems for PWR by using the best-estimate program, RELAP5. To simulate the full-scope power conversion system, not only the reactor coolant system (RCP) of nuclear island, but also the main steam system (VVP), turbine steam and drain system (GPV), bypass system (GCT), feedwater system (FW), condensate extraction system (CEX), moisture separator reheater system (GSS), turbine-driven feedwater pump (APP), low-pressure and high-pressure feedwater heater systems (ABP and AHP) of conventional island are considered and modeled. A comparison between the simulated results and the actual data of reactor under full-power demonstrates a fine match for Dayabay, and also manifests the feasibility in simulating full-scope power conversion system of PWR with RELAP5. (author)

  11. Controlling system for an experimental demonstration plant for energy conversion using PEMFCs

    International Nuclear Information System (INIS)

    Culcer, Mihail; Iliescu, Mariana; Stefanescu, Ioan; Raceanu, Mircea; Enache, Adrian; Patularu, Laurentiu

    2006-01-01

    Full text: In the last decades of the previous century, due to global environmental problems, energy security and supply issues, many studies were conducted to investigate the uses for hydrogen energy and facilitate its penetration as an energy carrier. Subsequently, many industries worldwide began developing and producing hydrogen, hydrogen-powered vehicles, hydrogen fuel cells, and other hydrogen-based technologies. In view of the substantial long-term public and private benefits arising from hydrogen and fuel cells, the European Union and national governments throughout Europe, including the Romanian one, are working towards developing a consistent policy framework preparing the transition to a hydrogen based economy. ICIT Rm Valcea developed a research program on energy conversion using fuel cells, a project supported by the Romanian Ministry of Education and Research within the National R and D Program. An experimental demonstration pilot plant of energy conversion using PEMFCs and hydrogen producing via steam methane reforming (SMR) was achieved in order to investigate the development of small-scale SMR technologies and to allow testing and developing of specific components. The paper deals with the dedicated controlling system that provides automated data acquisition, manual or 'on line' operational control, gas management, humidification, temperature and flow controls of the pilot plant. (authors)

  12. Talent Developed: Conversations with Masters of the Arts and Sciences.

    Science.gov (United States)

    Subotnik, Rena F.

    1994-01-01

    This interview with Philip Scheffler, a broadcast journalist and producer at the Columbia Broadcasting System (CBS), touches on his current job, his entry into television journalism, his high school experience, his family's values, his early educational experiences as a gifted student, the role of mentors, and his advice to aspiring young…

  13. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Conversion Pathway: Biological Conversion of Sugars to Hydrocarbons The 2017 Design Case

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J Bonner; Garold L. Gresham; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2013-09-01

    The U.S. Department of Energy promotes the production of a range of liquid fuels and fuel blendstocks from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass collection, conversion, and sustainability. As part of its involvement in this program, the Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL conducted a campaign to quantify the economics and sustainability of moving biomass from standing in the field or stand to the throat of the biomass conversion process. The goal of this program was to establish the current costs based on conventional equipment and processes, design improvements to the current system, and to mark annual improvements based on higher efficiencies or better designs. The 2012 programmatic target was to demonstrate a delivered biomass logistics cost of $35/dry ton. This goal was successfully achieved in 2012 by implementing field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model. Looking forward to 2017, the programmatic target is to supply biomass to the conversion facilities at a total cost of $80/dry ton and on specification with in-feed requirements. The goal of the 2017 Design Case is to enable expansion of biofuels production beyond highly productive resource areas by breaking the reliance of cost-competitive biofuel production on a single, abundant, low-cost feedstock. If this goal is not achieved, biofuel plants are destined to be small and/or clustered in select regions of the country that have a lock on low-cost feedstock. To put the 2017 cost target into perspective of past accomplishments of the cellulosic ethanol pathway, the $80 target encompasses total delivered feedstock cost, including both grower payment and logistics costs, while meeting all

  14. Multi-views storage model and access methods of conversation history in converged IP messaging system

    Science.gov (United States)

    Lu, Meilian; Yang, Dong; Zhou, Xing

    2013-03-01

    Based on the analysis of the requirements of conversation history storage in CPM (Converged IP Messaging) system, a Multi-views storage model and access methods of conversation history are proposed. The storage model separates logical views from physical storage and divides the storage into system managed region and user managed region. It simultaneously supports conversation view, system pre-defined view and user-defined view of storage. The rationality and feasibility of multi-view presentation, the physical storage model and access methods are validated through the implemented prototype. It proves that, this proposal has good scalability, which will help to optimize the physical data storage structure and improve storage performance.

  15. Preliminary conceptual design of the blanket and power conversion system for the Mirror Hybrid Reactor

    International Nuclear Information System (INIS)

    Schultz, K.R.; Culver, D.W.; Rao, S.B.; Rao, S.R.

    1978-01-01

    A conceptual design of a commercial Mirror Hybrid Reactor, optimized for 239 Pu production, has been completed. This design is the product of a joint effort by Lawrence Livermore Laboratory and General Atomic Company, and follows directly from earlier work on the Mirror Hybrid. This paper describes the blanket and power conversion system of the reactor design. Included are descriptions of the prestressed concrete reactor vessel that supports the magnets and contains the blanket and power conversion system components, the blanket module design, the blanket fuel design, and the power conversion system

  16. The principles of electronic and electromechanic power conversion a systems approach

    CERN Document Server

    Ferreira, Braham

    2013-01-01

    Teaching the principles of power electronics and electromechanical power conversion through a unique top down systems approach, The Principles of Electromechanical Power Conversion takes the role and system context of power conversion functions as the starting point. Following this approach, the text defines the building blocks of the system and describes the theory of how they exchange power with each other. The authors introduce a modern, simple approach to machines, which makes the principles of field oriented control and space vector theory approachable to undergraduate students as well as

  17. Reliability and mass analysis of dynamic power conversion systems with parallel or standby redundancy

    Science.gov (United States)

    Juhasz, Albert J.; Bloomfield, Harvey S.

    1987-01-01

    A combinatorial reliability approach was used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis was also performed, specifically for a 100-kWe nuclear Brayton power conversion system with parallel redundancy. Although this study was done for a reactor outlet temperature of 1100 K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

  18. Reliability and mass analysis of dynamic power conversion systems with parallel of standby redundancy

    Science.gov (United States)

    Juhasz, A. J.; Bloomfield, H. S.

    1985-01-01

    A combinatorial reliability approach is used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis is also performed, specifically for a 100 kWe nuclear Brayton power conversion system with parallel redundancy. Although this study is done for a reactor outlet temperature of 1100K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

  19. Making the Connection: Disarmament, Development and Economic Conversion. A Reader.

    Science.gov (United States)

    Gold, Howard, Ed.

    This document consists of articles which have been selected to provide insight into different aspects of the relationship between the two most pressing and challenging issues of the current time. The first is the need to achieve a just level of economic development for two-thirds of the world's population that live in poverty. The second is the…

  20. Development of conversion programs for formats of thermodynamic databases

    International Nuclear Information System (INIS)

    Yoshida, Yasushi; Yui, Mikazu

    2003-02-01

    Programs which enable to convert the database format from PHREEQE code to PHREEQC, EQ3/6 and Geochemist's Workbench code were developed and quality of these programs was checked. As a result, it was confirmed that these programs converted the database format correctly except for specific conditions which lead errors. (author)

  1. Energy Storage System with Voltage Equalization Strategy for Wind Energy Conversion

    Directory of Open Access Journals (Sweden)

    Cheng-Tao Tsai

    2012-07-01

    Full Text Available In this paper, an energy storage system with voltage equalization strategy for wind energy conversion is presented. The proposed energy storage system provides a voltage equalization strategy for series-connected lead-acid batteries to increase their total storage capacity and lifecycle. In order to draw the maximum power from the wind energy, a perturbation-and-observation method and digital signal processor (DSP are incorporated to implement maximum power point tracking (MPPT algorithm and power regulating scheme. In the proposed energy storage system, all power switches have zero-voltage-switching (ZVS feature at turn-on transition. Therefore, the conversion efficiency can be increased. Finally, a prototype energy storage system for wind energy conversion is built and implemented. Experimental results have verified the performance and feasibility of the proposed energy storage system for wind energy conversion.

  2. International Security, Development, and Human Rights: Policy Conversion or Conflict?

    Directory of Open Access Journals (Sweden)

    Miao-ling Lin Hasenkamp

    2012-04-01

    Full Text Available This article uses an institutional network governance approach to explore the overlapping dimension of the policy fields between security, development, and human rights, reflected in the US and German provincial reconstruction teams (PRTs in Afghanistan. The past two decades have witnessed a gradually changing paradigm in academic and policy debates regarding the questions of the normative basis of world order and possibilities for tackling imminent threats to security and peace (i.e. intra-state armed conflicts, failed states, terrorism, poverty, and deepening inequality. The introduction of concepts such as “human security” and “the right to humanitarian intervention/responsibility to protect (R2P” as well as critical examinations of peace-, nation-, and state-building missions (PNSB have led to a relativist tendency of state sovereignty and a changing attitude regarding how to address the intersection of security, development, and human rights. Despite this shift, the policy commitments to integrating these policy considerations remain puzzling. How have they been redefined, conceptualized, and put into practice? I argue that an integrated conceptual approach has facilitated the redefinition of common policy goals, principles, and the mobilization of resources. At the same time, civil and military cooperation, as demonstrated in the multifunctional work of PRTs, has been Janus-headed—permanently caught in an ongoing tension between the war on terror and short-term stability operation on the one hand and long-term durable peace and development on the other. The misunderstanding of its interim character, the dynamics of Afghan environment, the blurring of policy lines, and the differences between national PRT models have made it difficult to systematically assess the efficiency and legitimacy of each policy frame and program.

  3. POWER SYSTEMS DEVELOPMENT FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-11-01

    This report discusses test campaign GCT4 of the Kellogg Brown & Root, Inc. (KBR) transport reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The transport reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using one of two possible particulate control devices (PCDs). The transport reactor was operated as a pressurized gasifier during GCT4. GCT4 was planned as a 250-hour test run to continue characterization of the transport reactor using a blend of several Powder River Basin (PRB) coals and Bucyrus limestone from Ohio. The primary test objectives were: Operational Stability--Characterize reactor loop and PCD operations with short-term tests by varying coal-feed rate, air/coal ratio, riser velocity, solids-circulation rate, system pressure, and air distribution. Secondary objectives included the following: Reactor Operations--Study the devolatilization and tar cracking effects from transient conditions during transition from start-up burner to coal. Evaluate the effect of process operations on heat release, heat transfer, and accelerated fuel particle heat-up rates. Study the effect of changes in reactor conditions on transient temperature profiles, pressure balance, and product gas composition. Effects of Reactor Conditions on Synthesis Gas Composition--Evaluate the effect of air distribution, steam/coal ratio, solids-circulation rate, and reactor temperature on CO/CO{sub 2} ratio, synthesis gas Lower Heating Value (LHV), carbon conversion, and cold and hot gas efficiencies. Research Triangle Institute (RTI) Direct Sulfur Recovery Process (DSRP) Testing--Provide syngas in support of the DSRP commissioning. Loop Seal Operations--Optimize loop seal operations and investigate increases to previously achieved maximum solids-circulation rate.

  4. Three-Port dc-dc Conversion in Light-to-Light Systems

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen

    conversion efficiency under low irradiation conditions. This work is part of a Ph.D. research project to study the feasibility of implementing three-port converter (TPC) topologies in solar powered LED, light-to-light (LtL) systems. After the introduction in Chapter 1, an overview of the state-of-the art...... conventional light sources based on heated filaments (incandescent and halogen) and gas discharge (fluorescent, sodium, etc). The rapid development of this technology makes it possible to replace the conventional technologies towards high brightness LED lighting systems. The combination of these technologies......—solar cells, energy storage elements and LEDs—in a stand-alone solar powered LED system, can provide light where otherwise it would be cumbersome; in rural areas, where cabling can be challenging and expensive, and also in the urban environment, where the cost of digging and construction is very expensive...

  5. Conversion between EIT and Fano spectra in a microring-Bragg grating coupled-resonator system

    Science.gov (United States)

    Zhang, Zecen; Ng, Geok Ing; Hu, Ting; Qiu, Haodong; Guo, Xin; Wang, Wanjun; Rouifed, Mohamed Saïd; Liu, Chongyang; Wang, Hong

    2017-08-01

    A conversion between the electromagnetically induced transparency (EIT) transmission and Fano transmission is theoretically and experimentally demonstrated in an all-pass microring-Bragg grating (APMR-BG) coupled-resonator system. In this work, the coupling between the two resonators (the microring resonator and the Fabry-Perot resonator formed by two Bragg gratings) gives rise to the EIT and Fano transmissions. The resonant status strongly depends on the round-trip attenuation of the microring and the coupling strength. By tuning the coupling strength, the EIT and Fano transmissions can be controlled and converted. The device performance has been theoretically calculated and analyzed with a specially developed numerical model based on the transfer matrix method. The APMR-BG coupled-resonator systems with different gap widths were designed, fabricated, and characterized on a silicon-on-insulator (SOI) platform. The conversion of resonance was experimentally observed and verified. In addition, this on-chip system has the advantage of a small footprint, and the fabrication process is compatible with the planar waveguide fabrication process.

  6. Steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Fang, Jiakun; Li, Jinghua

    2016-01-01

    Nowadays, the electric power system and natural gas network are becoming increasingly coupled and interdependent. A harmonized integration of natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables in terms of system...... flexibility. This work focuses on the steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion. A unified energy flow formulation is developed to describe the nodal balance and branch flow in both systems and it is solved with the Newton......–Raphson method. Both the unification of units and the per-unit system are proposed to simplify the system description and to enhance the computation efficiency. The applicability of the proposed method is demonstrated by analyzing an IEEE-9 test system integrated with a 7-node natural gas network. Later, time...

  7. Basic and applied research related to the technology of space energy conversion systems, 1982 - 1983

    Science.gov (United States)

    Hertzberg, A.

    1983-01-01

    Topics on solar energy conversion concepts and applications are discussed. An overview of the current status and future utilization of radiation receivers for electrical energy generation, liquid droplet radiation systems, and liquid droplet heat exchangers is presented.

  8. The influence of external source intensity in accelerator/target/blanket system on conversion ratio and fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Kochurov, B.P. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

    1995-10-01

    The analysis of neutron balance relation for a subcritical system with external source shows that a high ratio of neutron utilization (conversion ratio, breeding ratio) much exceeding similar values for nuclear reactors (both thermal or fast spectrum) is reachable in accelerator/target/blanket system with high external neutron source intensity. An accelerator/target/blanket systems with thermal power in blanket about 1850 Mwt and operating during 30 years have been investigated. Continual feed up by plutonium (fissile material) and Tc-99 (transmuted material) was assumed. Accelerator beam intensity differed 6.3 times (16 mA - Case 1, and 100 mA-Case 2). Conversion ratio (CR) was defined as the ratio of Tc-99 nuclei transmuted to the number of Pu nuclei consumed. High value of conversion ratio considerably exceeding 1 (CR=1.66) was obtained in the system with high source intensity as compared with low source system (CR=0.77). Net output of electric power of high source intensity system is about twice lower due to consumption of electric power for accelerator feed up. The loss of energy for Tc-99 transmutation is estimated as 40 Mev(el)/nuclei. Yet high conversion ratio (or breeding ratio) achievable in electronuclear installations with high intensity of external source can effectively be used to close fuel cycle (including incineration of wastes) or to develop growing nuclear power production system.

  9. The LEU target development and conversion program for the MAPLE reactors and new processing facility

    International Nuclear Information System (INIS)

    Malkoske, G.R.

    2003-01-01

    The availability of isotope grade, Highly Enriched Uranium (HEU), from the United States for use in the manufacture of targets for molybdenum-99 production in AECL's NRU research reactor has been a key factor to enable MDS Nordion to develop a reliable, secure supply of medical isotopes for the international nuclear medicine community. The molybdenum extraction process from HEU targets is a proven and established method that has reliably produced medical isotopes for several decades. The HEU process provides predictable, consistent yields for our high-volume, molybdenum-99 production. Other medical isotopes such as I-131 and Xe-133, which play an important role in nuclear medicine applications, are also produced from irradiated HEU targets as a by-product of the molybdenum-99 process. To ensure a continued reliable and timely supply of medical isotopes, MDS Nordion is completing the commissioning of two MAPLE reactors and an associated isotope processing facility (the New Processing Facility). The new MAPLE facilities, which will be dedicated exclusively to medical isotope production, will provide an essential contribution to a secure, robust global healthcare system. Design and construction of these facilities has been based on a life cycle management philosophy for the isotope production process. This includes target irradiation, isotope extraction and waste management. The MAPLE reactors will operate with Low Enriched Uranium (LEU) fuel, a significant contribution to the objectives of the RERTR program. The design of the isotope production process in the MAPLE facilities is based on an established process - extraction of isotopes from HEU target material. This is a proven technology that has been demonstrated over more than three decades of operation. However, in support of the RERTR program and in compliance with U.S. legislation, MDS Nordion has undertaken a LEU Target Development and Conversion Program for the MAPLE facilities. This paper will provide an

  10. Technical Development for S-CO2 Advanced Energy Conversion

    International Nuclear Information System (INIS)

    Anderson, Mark; Ranjan, Devesh; Hassan, Yassin

    2014-01-01

    up to 60,000, at operating pressures of 7.5, 8.1, and 10.2 MPa were tested in a round tube. Local heat transfer coefficients were obtained from measured wall temperatures over a large set of experimental parameters that varied inlet temperature from 20 °C to 55 °C,mass flux from 150 to 350 kg/m 2 s, and a maximum heat flux of 65 KW/m 2 . Horizontal, upward and downward flows were tested to investigate the unusual heat-transfer characteristics to the effect of buoyancy and flow acceleration caused by large variation in density. Final part of this report presents the simplified analysis performed to investigate the possibility of using wet cooling tower option to reject heat from the supercritical carbon dioxide Brayton cycle power convertor for AFR-100 and ABR-1000 plants. A code was developed to estimate the tower dimensions, power and water consumption, and to perform economic analysis. The code developed was verified by comparing the calculations to a vendor quote. The effect of ambient air and water conditions on the sizing and construction of the cooling tower as well as the cooler is studied. Finally, a cost-based optimization technique is used to estimate the optimum water conditions which will improve the plant economics.

  11. Archetype-based conversion of EHR content models: pilot experience with a regional EHR system

    Science.gov (United States)

    2009-01-01

    Background Exchange of Electronic Health Record (EHR) data between systems from different suppliers is a major challenge. EHR communication based on archetype methodology has been developed by openEHR and CEN/ISO. The experience of using archetypes in deployed EHR systems is quite limited today. Currently deployed EHR systems with large user bases have their own proprietary way of representing clinical content using various models. This study was designed to investigate the feasibility of representing EHR content models from a regional EHR system as openEHR archetypes and inversely to convert archetypes to the proprietary format. Methods The openEHR EHR Reference Model (RM) and Archetype Model (AM) specifications were used. The template model of the Cambio COSMIC, a regional EHR product from Sweden, was analyzed and compared to the openEHR RM and AM. This study was focused on the convertibility of the EHR semantic models. A semantic mapping between the openEHR RM/AM and the COSMIC template model was produced and used as the basis for developing prototype software that performs automated bi-directional conversion between openEHR archetypes and COSMIC templates. Results Automated bi-directional conversion between openEHR archetype format and COSMIC template format has been achieved. Several archetypes from the openEHR Clinical Knowledge Repository have been imported into COSMIC, preserving most of the structural and terminology related constraints. COSMIC templates from a large regional installation were successfully converted into the openEHR archetype format. The conversion from the COSMIC templates into archetype format preserves nearly all structural and semantic definitions of the original content models. A strategy of gradually adding archetype support to legacy EHR systems was formulated in order to allow sharing of clinical content models defined using different formats. Conclusion The openEHR RM and AM are expressive enough to represent the existing clinical

  12. Archetype-based conversion of EHR content models: pilot experience with a regional EHR system

    Directory of Open Access Journals (Sweden)

    Karlsson Daniel

    2009-07-01

    Full Text Available Abstract Background Exchange of Electronic Health Record (EHR data between systems from different suppliers is a major challenge. EHR communication based on archetype methodology has been developed by openEHR and CEN/ISO. The experience of using archetypes in deployed EHR systems is quite limited today. Currently deployed EHR systems with large user bases have their own proprietary way of representing clinical content using various models. This study was designed to investigate the feasibility of representing EHR content models from a regional EHR system as openEHR archetypes and inversely to convert archetypes to the proprietary format. Methods The openEHR EHR Reference Model (RM and Archetype Model (AM specifications were used. The template model of the Cambio COSMIC, a regional EHR product from Sweden, was analyzed and compared to the openEHR RM and AM. This study was focused on the convertibility of the EHR semantic models. A semantic mapping between the openEHR RM/AM and the COSMIC template model was produced and used as the basis for developing prototype software that performs automated bi-directional conversion between openEHR archetypes and COSMIC templates. Results Automated bi-directional conversion between openEHR archetype format and COSMIC template format has been achieved. Several archetypes from the openEHR Clinical Knowledge Repository have been imported into COSMIC, preserving most of the structural and terminology related constraints. COSMIC templates from a large regional installation were successfully converted into the openEHR archetype format. The conversion from the COSMIC templates into archetype format preserves nearly all structural and semantic definitions of the original content models. A strategy of gradually adding archetype support to legacy EHR systems was formulated in order to allow sharing of clinical content models defined using different formats. Conclusion The openEHR RM and AM are expressive enough to

  13. Modeling of large aperture third harmonic frequency conversion of high power Nd:glass laser systems

    International Nuclear Information System (INIS)

    Henesian, M.A.; Wegner, P.J.; Speck, D.R.; Bibeau, C.; Ehrlich, R.B.; Laumann, C.W.; Lawson, J.K.; Weiland, T.L.

    1991-01-01

    To provide high-energy, high-power beams at short wavelengths for inertial-confinement-fusion experiments, we routinely convert the 1.053-μm output of the Nova, Nd:phosphate-glass, laser system to its third-harmonic wavelength. We describe performance and conversion efficiency modeling of the 3 x 3 arrays potassium-dihydrogen-phosphate crystal plates used for type II/type II phase-matched harmonic conversion of Nova 0.74-m diameter beams, and an alternate type I/type II phase-matching configuration that improves the third-harmonic conversion efficiency. These arrays provide energy conversion of up to 65% and intensity conversion to 70%. 19 refs., 11 figs

  14. Modeling and Coordinated Control Strategy of Large Scale Grid-Connected Wind/Photovoltaic/Energy Storage Hybrid Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Lingguo Kong

    2015-01-01

    Full Text Available An AC-linked large scale wind/photovoltaic (PV/energy storage (ES hybrid energy conversion system for grid-connected application was proposed in this paper. Wind energy conversion system (WECS and PV generation system are the primary power sources of the hybrid system. The ES system, including battery and fuel cell (FC, is used as a backup and a power regulation unit to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic resources. Static synchronous compensator (STATCOM is employed to support the AC-linked bus voltage and improve low voltage ride through (LVRT capability of the proposed system. An overall power coordinated control strategy is designed to manage real-power and reactive-power flows among the different energy sources, the storage unit, and the STATCOM system in the hybrid system. A simulation case study carried out on Western System Coordinating Council (WSCC 3-machine 9-bus test system for the large scale hybrid energy conversion system has been developed using the DIgSILENT/Power Factory software platform. The hybrid system performance under different scenarios has been verified by simulation studies using practical load demand profiles and real weather data.

  15. R and D on the power conversion system for gas turbine high temperature reactors

    International Nuclear Information System (INIS)

    Takizuka, Takakazu; Takada, Shoji; Yan Xing; Kosugiyama, Shinichi; Katanishi, Shoji; Kunitomi, Kazuhiko

    2004-01-01

    JAERI is conducting R and D on the power conversion system of the GTHTR300 plant, in parallel with plant design work. The design of the power conversion system is based on a regenerative, non-intercooled, closed Brayton cycle with helium gas as the working fluid. A single-shaft, axial-flow turbo-compressor and a directly coupled electric generator run on magnetic bearings. Major R and D issues for the power conversion system are aerodynamic performance of the helium gas compressor, high load capacity magnetic bearings and performance of magnetic bearing supported rotor, and operability and controllability of the closed-cycle gas turbine system. Three test plans were set up to address theses issues, aiming at verifying the design of the GTHTR300 power conversion system and establishing key technologies of a closed-cycle helium gas turbine system. The compressor aerodynamic performance test is aiming at verifying the aerodynamic performance and design method of the helium compressor. A 1/3-scale, four-stage compressor test model and a helium gas loop were designed and fabricated. The model was designed to simulate the repeating stage flow, and at the same time have satisfactorily high machining precision, Reynolds number and measurement accuracy. The helium gas operating pressure is varied to investigate the effects of the Reynolds number on the efficiency and surge margin. Two sets of blades were fabricated to evaluate the effects of the end-wall over-camber angle. Test results will provide the basis for further improvement in the GTHTR300 compressor design. The magnetic bearing development test is aiming at developing the technology of the magnetic bearing supported rotor system. The test rig composed of 1/3-scale turbo-compressor and generator rotor models that are connected together by a flexible coupling. Each rotor models are supported by two radial magnetic bearings with a high load capacity that is about 1/10 of the GTHTR300 design. The rotor models were

  16. Extended exergy concept to facilitate designing and optimization of frequency-dependent direct energy conversion systems

    International Nuclear Information System (INIS)

    Wijewardane, S.; Goswami, Yogi

    2014-01-01

    Highlights: • Proved exergy method is not adequate to optimize frequency-dependent energy conversion. • Exergy concept is modified to facilitate the thermoeconomic optimization of photocell. • The exergy of arbitrary radiation is used for a practical purpose. • The utility of the concept is illustrated using pragmatic examples. - Abstract: Providing the radiation within the acceptable (responsive) frequency range(s) is a common method to increase the efficiency of the frequency-dependent energy conversion systems, such as photovoltaic and nano-scale rectenna. Appropriately designed auxiliary items such as spectrally selective thermal emitters, optical filters, and lenses are used for this purpose. However any energy conversion method that utilizes auxiliary components to increase the efficiency of a system has to justify the potential cost incurred by those auxiliary components through the economic gain emerging from the increased system efficiency. Therefore much effort should be devoted to design innovative systems, effectively integrating the auxiliary items and to optimize the system with economic considerations. Exergy is the widely used method to design and optimize conventional energy conversion systems. Although the exergy concept is used to analyze photovoltaic systems, it has not been used effectively to design and optimize such systems. In this manuscript, we present a modified exergy method in order to effectively design and economically optimize frequency-dependent energy conversion systems. Also, we illustrate the utility of this concept using examples of thermophotovoltaic, Photovoltaic/Thermal and concentrated solar photovoltaic

  17. Study of the application of a near-real-time materials accountancy system for a model plutonium conversion plants

    International Nuclear Information System (INIS)

    Ihara, Hitoshi; Ikawa, Koji

    1986-11-01

    An assessment was done on the potential capability of a Near-Real-Time materials accountancy system for a model plutonium conversion plant. To this end, a computer simulation system, DYSAS-C, has been developed and evaluated through this assessment study. This study showed that N.R.T.A system could be used not only as a good operator's accounting system but also as a useful inspectorate's system to detect an abrupt diversion. It also showed, however, that more elaborated NRTA system which have not yet evaluated in this study should be considerered when we wish to improve of detecting protracted diversion. (author)

  18. Modeling of the interplay between single-file diffusion and conversion reaction in mesoporous systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing [Iowa State Univ., Ames, IA (United States)

    2013-01-11

    We analyze the spatiotemporal behavior of species concentrations in a diffusion-mediated conversion reaction which occurs at catalytic sites within linear pores of nanometer diameter. A strict single-file (no passing) constraint occurs in the diffusion within such narrow pores. Both transient and steady-state behavior is precisely characterized by kinetic Monte Carlo simulations of a spatially discrete lattice–gas model for this reaction–diffusion process considering various distributions of catalytic sites. Exact hierarchical master equations can also be developed for this model. Their analysis, after application of mean-field type truncation approximations, produces discrete reaction–diffusion type equations (mf-RDE). For slowly varying concentrations, we further develop coarse-grained continuum hydrodynamic reaction–diffusion equations (h-RDE) incorporating a precise treatment of single-file diffusion (SFD) in this multispecies system. Noting the shortcomings of mf-RDE and h-RDE, we then develop a generalized hydrodynamic (GH) formulation of appropriate gh-RDE which incorporates an unconventional description of chemical diffusion in mixed-component quasi-single-file systems based on a refined picture of tracer diffusion for finite-length pores. The gh-RDE elucidate the non-exponential decay of the steady-state reactant concentration into the pore and the non-mean-field scaling of the reactant penetration depth. Then an extended model of a catalytic conversion reaction within a functionalized nanoporous material is developed to assess the effect of varying the reaction product – pore interior interaction from attractive to repulsive. The analysis is performed utilizing the generalized hydrodynamic formulation of the reaction-diffusion equations which can reliably capture the complex interplay between reaction and restricted transport for both irreversible and reversible reactions.

  19. Experimental Study of Heat Energy Absorber with Porous Medium for Thermoelectric Conversion System

    Directory of Open Access Journals (Sweden)

    Tzer-Ming Jeng

    2013-12-01

    Full Text Available The thermoelectric conversion system usually consists of the heat absorber, the thermoelectric generator (TEG and the heat sink, while the heat absorber collects the heat to increase the temperature on the hot surface of TEG and enhances the generating electricity. This study experimentally investigated the performance of the brass-beads packed-bed heat absorber for the thermoelectric conversion system. The packed-bed heat absorber is installed in a square channel with the various flow orientation systems and the small ratio of channel width to bead diameter. The flow orientation systems included the straight flow and jet flow systems. This study showed the local and average heat transfer characteristics for various parameters. The experimental results can be the base of designs for the novel porous heat absorber of the thermoelectric conversion system.

  20. Development and manufacturing cycle for potassium nitrate and phosphate producing by conversion method

    Directory of Open Access Journals (Sweden)

    А. И. Алексеев

    2016-11-01

    Full Text Available Analysis of the Russian market of potash mineral fertilizers in 2014 and forecast for 2015-2019 show [http://businesstat.ru/images/demo/potash_fertilizers_russia.pdf] that today the most widespread potash fertilizer is  the potassium chloride. But chloride-free potassium-containing products are in the highest demand at the fertilizer market. One of possible solutions to this problem is recrystallization of the potassium chloride or potassium-containing mineral ores using nitrate-containing or phosphorus-containing salt products. The basis for justifying processing conditions for polymineral potassium-containing salt raw materials and salt mineral ores is the data on phase equilibria in multicomponent water-salt systems. Knowledge of the regularities of phase equilibria in multicomponent salt systems helps to develop optimal conditions for complex processing of polymineral natural and technical raw materials. Below it is present the results of technological calculations for processing potash mineral raw materials with account of the complex nature of its utilization. Based on the analysis of the solubility diagrams of mutual salt systems different cyclic processes for production of potassium dihydrogen phosphate and nitrate and sodium chloride from dihydrogen phosphate and sodium nitrate and potassium chloride by conversion method have been designed, and ways of these processes optimization have been proposed for reducing the cost of certain technical  operations.

  1. Topological energy conversion through the bulk or the boundary of driven systems

    Science.gov (United States)

    Peng, Yang; Refael, Gil

    2018-04-01

    Combining physical and synthetic dimensions allows a controllable realization and manipulation of high-dimensional topological states. In our work, we introduce two quasiperiodically driven one-dimensional systems which enable tunable topological energy conversion between different driving sources. Using three drives, we realize a four-dimensional quantum Hall state which allows energy conversion between two of the drives within the bulk of the one-dimensional system. With only two drives, we achieve energy conversion between the two at the edge of the chain. Both effects are a manifestation of the effective axion electrodynamics in a three-dimensional time-reversal-invariant topological insulator. Furthermore, we explore the effects of disorder and commensurability of the driving frequencies, and show the phenomena are robust. We propose two experimental platforms, based on semiconductor heterostructures and ultracold atoms in optical lattices, in order to observe the topological energy conversion.

  2. Efficiency calculations for the direct energy conversion system of the Cadarache neutral beam injectors

    International Nuclear Information System (INIS)

    White, R.C.

    1988-01-01

    A prototype energy conversion system is presently in operation at Cadarache, France. Such a device is planned for installation on each six neutral beam injectors for use in the Tore Supra experiment in 1989. We present calculations of beam performance that may influence design considerations. The calculations are performed with the DART charged particle beam code. We investigate the effects of cold plasma, direct energy conversion and neutral beam production. 4 refs., 6 figs., 4 tabs

  3. Structuring Health in Colorectal Cancer Screening Conversations: An Analysis of Intersecting Activity Systems

    OpenAIRE

    Canary, Heather; Bullis, Connie; Cummings, Jennifer; Kinney, Anita Y.

    2015-01-01

    This study used structurating activity theory to analyze 21 conversations between genetic counselors and individuals at increased risk for familial colorectal cancer (CRC). The qualitative analysis revealed ways elements of family, primary healthcare, cancer prevention and treatment, and other systems emerged in intervention conversations as shaping CRC screening attitudes and behaviors. Results indicate that family stories, norms, and roles are resources for enacting health practices in fami...

  4. Design and analysis of Helium Brayton cycle for energy conversion system of RGTT200K

    International Nuclear Information System (INIS)

    Ignatius Djoko Irianto

    2016-01-01

    The helium Brayton cycle for the design of cogeneration energy conversion system for RGTT200K have been analyzed to obtain the higher thermal efficiency and energy utilization factor. The aim of this research is to analyze the potential of the helium Brayton cycle to be implemented in the design of cogeneration energy conversion system of RGTT200K. Three configuration models of cogeneration energy conversion systems have been investigated. In the first configuration model, an intermediate heat exchanger (IHX) is installed in series with the gas turbine, while in the second configuration model, IHX and gas turbines are installed in parallel. The third configuration model is similar to the first configuration, but with two compressors. Performance analysis of Brayton cycle used for cogeneration energy conversion system of RGTT200K has been done by simulating and calculating using CHEMCAD code. The simulation result shows that the three configuration models of cogeneration energy conversion system give the temperature of thermal energy in the secondary side of IHX more than 800 °C at the reactor coolant mass flow rate of 145 kg/s. Nevertheless, the performance parameters, which include thermal efficiency and energy utilization factor (EUF), are different for each configuration model. By comparing the performance parameter in the three configurations of helium Brayton cycle for cogeneration energy conversion systems RGTT200K, it is found that the energy conversion system with a first configuration has the highest thermal efficiency and energy utilization factor (EUF). Thermal efficiency and energy utilization factor for the first configuration of the reactor coolant mass flow rate of 145 kg/s are 35.82 % and 80.63 %. (author)

  5. Theme--Achieving 2020. Goal 3: All Students Are Conversationally Literate in Agriculture, Food, Fiber, and Natural Resource Systems.

    Science.gov (United States)

    Trexler, Cary, Ed.

    2000-01-01

    Nine theme articles focus on the need for students to be conversationally literate about agriculture, food, fiber, and natural resources systems. Discusses the definition of conversational literacy, the human and institutional resources needed, and exemplary models for promoting literacy. (JOW)

  6. Electrochemical conversion technologies for optimal design of decentralized multi-energy systems : Modeling framework and technology assessment

    NARCIS (Netherlands)

    Gabrielli, Paolo; Gazzani, Matteo; Mazzotti, Marco

    2018-01-01

    The design and operation of integrated multi-energy systems require models that adequately describe the behavior of conversion and storage technologies. Typically, linear conversion performance or fixed data from technology manufacturers are employed, especially for new or advanced technologies.

  7. Module-level DC/DC conversion for photovoltaic systems

    NARCIS (Netherlands)

    Bergveld, H.J.; Büthker, D.; Castello, C.; Doorn, T.S.; Jong, de A.; van Otten, R.; Waal, de K.

    2011-01-01

    Photovoltaic (PV) systems are increasingly used to generate electrical energy from solar irradiance incident on PV modules. Each PV module is formed by placing a large amount of PV cells, typically 60, in series. The PV system is then formed by placing a number, typically 10–12, of PV modules in

  8. A pathway for sustainable conversion of sunlight to hydrogen using proposed compact CPV system

    KAUST Repository

    Burhan, Muhammad

    2018-03-22

    Solar energy being intermittent in nature, can provide a sustainable, steady and high density energy source when converted into electrolytic hydrogen. However, in current photovoltaic market trend with 99% conventional single junction PV panels, this cannot be achieved efficiently and economically. The advent of the multi-junction solar cells (MJCs), with cell-efficiency exceeding 46%, has yet to receive wide spread acceptance in the current PV market in form of concentrated photovoltaic (CPV) system, because of its system design complexity, limiting its application scope and customers. The objective of this paper is to develop a low cost compact CPV system that will not only eliminate its application and installation related restrictions but it is also introducing a highly efficient and sustainable photovoltaic system for common consumer, to convert intermittent sunlight into green hydrogen. The developed CPV system negates the common conviction by showing two times more power output than the flat plate PV, in tropical region. In addition, sunlight to hydrogen conversion efficiency of 18% is recorded for CPV, which is two times higher than alone electricity production efficiency of flat plate PV.

  9. A pathway for sustainable conversion of sunlight to hydrogen using proposed compact CPV system

    KAUST Repository

    Burhan, Muhammad; Shahzad, Muhammad Wakil; Oh, Seung Jin; Ng, Kim Choon

    2018-01-01

    Solar energy being intermittent in nature, can provide a sustainable, steady and high density energy source when converted into electrolytic hydrogen. However, in current photovoltaic market trend with 99% conventional single junction PV panels, this cannot be achieved efficiently and economically. The advent of the multi-junction solar cells (MJCs), with cell-efficiency exceeding 46%, has yet to receive wide spread acceptance in the current PV market in form of concentrated photovoltaic (CPV) system, because of its system design complexity, limiting its application scope and customers. The objective of this paper is to develop a low cost compact CPV system that will not only eliminate its application and installation related restrictions but it is also introducing a highly efficient and sustainable photovoltaic system for common consumer, to convert intermittent sunlight into green hydrogen. The developed CPV system negates the common conviction by showing two times more power output than the flat plate PV, in tropical region. In addition, sunlight to hydrogen conversion efficiency of 18% is recorded for CPV, which is two times higher than alone electricity production efficiency of flat plate PV.

  10. Development of a transition radiation detector and reconstruction of photon conversions in the CBM experiment

    International Nuclear Information System (INIS)

    Klein-Boesing, Melanie

    2009-01-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. In addition, the usage of the TRD in the measurement of direct photons is investigated. CBM will be a fixed-target heavy-ion experiment, which investigates collisions in the beam energy range of 5-35 AGeV and aims to investigate the regime of high baryon densities where the phase transition is expected to be of first order. It will be a multipurpose experiment with the ability to measure leptons, hadrons, and photons. Therein, a TRD will provide the electron identification and - together with a Silicon Tracking System (STS) - the tracking of charged particles. In conjunction with a ring imaging Cherenkov (RICH) detector and a time-of-flight (TOF) measurement, the TRD is to provide a sufficient electron identification for the measurements of charmonium and low-mass vector mesons. For the TRD, the required pion suppression is a factor of about 100 at 90% electron efficiency, and the position resolution has to be of the order of 300 to 500 um. Moreover, the material budget in terms of radiation length has to be kept at a minimum in order to minimize multiple scattering and conversions which would limit the precise measurement in following TRD stations and other detectors. The largest and up to now unrivaled challenge for the TRD design is that both (PID and tracking) have to be fulfilled in the context of very high particle rates (event rates of up to 10MHz are envisaged) and at the same time large charged-particle multiplicities of up to 600 per event in the CBM detector acceptance. Small prototypes of the TRD based on multiwire proportional chambers (MWPC) with pad readout were developed and tested. The tracking performance and the electron-pion separation were determined for particle rates of up to 200 kHz/cm 2 . The TRD layout and the detector responses

  11. Development of a transition radiation detector and reconstruction of photon conversions in the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Klein-Boesing, Melanie

    2009-07-01

    The focus of this thesis is the development of a Transition Radiation Detector (TRD) for the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. In addition, the usage of the TRD in the measurement of direct photons is investigated. CBM will be a fixed-target heavy-ion experiment, which investigates collisions in the beam energy range of 5-35 AGeV and aims to investigate the regime of high baryon densities where the phase transition is expected to be of first order. It will be a multipurpose experiment with the ability to measure leptons, hadrons, and photons. Therein, a TRD will provide the electron identification and - together with a Silicon Tracking System (STS) - the tracking of charged particles. In conjunction with a ring imaging Cherenkov (RICH) detector and a time-of-flight (TOF) measurement, the TRD is to provide a sufficient electron identification for the measurements of charmonium and low-mass vector mesons. For the TRD, the required pion suppression is a factor of about 100 at 90% electron efficiency, and the position resolution has to be of the order of 300 to 500 um. Moreover, the material budget in terms of radiation length has to be kept at a minimum in order to minimize multiple scattering and conversions which would limit the precise measurement in following TRD stations and other detectors. The largest and up to now unrivaled challenge for the TRD design is that both (PID and tracking) have to be fulfilled in the context of very high particle rates (event rates of up to 10MHz are envisaged) and at the same time large charged-particle multiplicities of up to 600 per event in the CBM detector acceptance. Small prototypes of the TRD based on multiwire proportional chambers (MWPC) with pad readout were developed and tested. The tracking performance and the electron-pion separation were determined for particle rates of up to 200 kHz/cm{sup 2}. The TRD layout and the detector

  12. Accident analysis of heat pipe cooled and AMTEC conversion space reactor system

    International Nuclear Information System (INIS)

    Yuan, Yuan; Shan, Jianqiang; Zhang, Bin; Gou, Junli; Bo, Zhang; Lu, Tianyu; Ge, Li; Yang, Zijiang

    2016-01-01

    Highlights: • A transient analysis code TAPIRS for HPS has been developed. • Three typical accidents are analyzed using TAPIRS. • The reactor system has the self-stabilization ability under accident conditions. - Abstract: A space power with high power density, light weight, low cost and high reliability is of crucial importance to future exploration of deep space. Space reactor is an excellent candidate because of its unique characteristics of high specific power, low cost, strong environment adaptability and so on. Among all types of space reactors, heat pipe cooled space reactor, which adopts the passive heat pipe (HP) as core cooling component, is considered as one of the most promising choices and is widely studied all over the world. This paper develops a transient analysis code (TAPIRS) for heat pipe cooled space reactor power system (HPS) based on point reactor kinetics model, lumped parameter core heat transfer model, combined HP model (self-diffusion model, flat-front startup model and network model), energy conversion model of Alkali Metal Thermal-to-Electric Conversion units (AMTEC), and HP radiator model. Three typical accidents, i.e., control drum failure, AMTEC failure and partial loss of the heat transfer area of radiator are then analyzed using TAPIRS. By comparing the simulation results of the models and steady state with those in the references, the rationality of the models and the solution method is validated. The results show the following. (1) After the failure of one set of control drums, the reactor power finally reaches a stable value after two local peaks under the temperature feedback. The fuel temperature rises rapidly, however it is still under safe limit. (2) The fuel temperature is below a safe limit under the AMTEC failure and partial loss of the heat transfer area of radiator. This demonstrates the rationality of the system design and the potential applicability of the TAPIRS code for the future engineering application of

  13. Research and evaluation of biomass resources/conversion/utilization systems (market/experimental analysis for development of a data base for a fuels from biomass model. Volume I. Biomass allocation model. Technical progress report for the period ending September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Y.K.; Chen, H.T.; Helm, R.W.; Nelson, E.T.; Shields K.J.

    1980-01-01

    A biomass allocation model has been developed to show the most profitable combination of biomass feedstocks thermochemical conversion processes, and fuel products to serve the seasonal conditions in a regional market. This optimization model provides a tool for quickly calculating the most profitable biomass missions from a large number of potential biomass missions. Other components of the system serve as a convenient storage and retrieval mechanism for biomass marketing and thermochemical conversion processing data. The system can be accessed through the use of a computer terminal, or it could be adapted to a portable micro-processor. A User's Manual for the system has been included in Appendix A of the report. The validity of any biomass allocation solution provided by the allocation model is dependent on the accuracy of the data base. The initial data base was constructed from values obtained from the literature, and, consequently, as more current thermochemical conversion processing and manufacturing costs and efficiencies become available, the data base should be revised. Biomass derived fuels included in the data base are the following: medium Btu gas low Btu gas, substitute natural gas, ammonia, methanol, electricity, gasoline, and fuel oil. The market sectors served by the fuels include: residential, electric utility, chemical (industrial), and transportation. Regional/seasonal costs and availabilities and heating values for 61 woody and non-woody biomass species are included. The study has included four regions in the United States which were selected because there was both an availability of biomass and a commercial demand for the derived fuels: Region I: NY, WV, PA; Region II: GA, AL, MS; Region III: IN, IL, IA; and Region IV: OR, WA.

  14. An update on the LEU target development and conversion program for the MAPLE reactors and new processing facility

    International Nuclear Information System (INIS)

    Malkoske, G.R.; Eng, B.Sc; Eng, P.

    2002-01-01

    Historically, the production of molybdenum-99 in the NRU research reactors at Chalk River, Canada, has been extracted from reactor targets employing highly enriched uranium (HEU). A reliable supply of HEU metal from the United States used in the manufacture of targets for the NRU research reactor has been a key factor to enable MDS Nordion to develop a secure supply of medical isotopes for the international nuclear medicine community. The molybdenum extraction process from HEU targets provides predictable, consistent yields for our high-volume molybdenum production process. Each link of the isotope supply chain, from isotope production to ultimate use by the physician, has been established using this proven and established method of HEU target irradiation and processing to extract molybdenum-99. To ensure a continued reliable and timely supply of medical isotopes, MDS Nordion is completing the construction of two MAPLE reactors and a New Processing Facility. The design of the MAPLE facilities was based on an established process developed by Atomic Energy of Canada Ltd. (AECL)-extraction of isotopes from HEU target material. However, in concert with the global trend to utilize low enriched uranium (LEU) in research reactors, MDS Nordion has launched a three phase LEU Target Development and Conversion Program for the MAPLE facilities. Phase 1, the Initial Feasibility Study, which identified the technical issues to convert the MAPLE reactor targets from HEU to LEU for large scale commercial production was reported on at the RERTR-2000 conference. The second phase of the LEU Target Development and Conversion Program was developed with extensive consultation and involvement of experts knowledgeable in target development, process system design, enriched uranium conversion chemistry and commercial scale reactor operations and molybdenum production. This paper will provide an overview of the Phase 2 Conversion Development Program, report on progress to date, and further

  15. Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides

    International Nuclear Information System (INIS)

    Andrade, Vitor S.C. de; Mattos, Marcio C.S. de

    2014-01-01

    An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzilic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions. (author)

  16. Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Vitor S.C. de; Mattos, Marcio C.S. de, E-mail: mmattos@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica. Departamento de Quimica Organica

    2014-05-15

    An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzilic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions. (author)

  17. Inertial confinement fusion reaction chamber and power conversion system study. Final report

    International Nuclear Information System (INIS)

    Maya, I.; Schultz, K.R.; Bourque, R.F.

    1985-10-01

    This report summarizes the results of the second year of a two-year study on the design and evaluation of the Cascade concept as a commercial inertial confinement fusion (ICF) reactor. We developed a reactor design based on the Cascade reaction chamber concept that would be competitive in terms of both capital and operating costs, safe and environmentally acceptable in terms of hazard to the public, occupational exposure and radioactive waste production, and highly efficient. The Cascade reaction chamber is a double-cone-shaped rotating drum. The granulated solid blanket materials inside the rotating chamber are held against the walls by centrifugal force. The fusion energy is captured in a blanket of solid carbon, BeO, and LiAlO 2 granules. These granules are circulated to the primary side of a ceramic heat exchanger. Primary-side granule temperatures range from 1285 K at the LiAlO 2 granule heat exchanger outlet to 1600 K at the carbon granule heat exchanger inlet. The secondary side consists of a closed-cycle gas turbine power conversion system with helium working fluid, operating at 1300 K peak outlet temperature and achieving a thermal power conversion efficiency of 55%. The net plant efficiency is 49%. The reference design is a plant producing 1500 MW of D-T fusion power and delivering 815 MW of electrical power for sale to the utility grid. 88 refs., 44 figs., 47 tabs

  18. Making the Connection: Disarmament, Development and Economic Conversion. A Resource Guide.

    Science.gov (United States)

    Gold, Howard, Ed.

    This nine-part guide provides resources on various topics and issues related disarmament, development, and economic conversion. They include: (1) recent publications (with their tables of contents provided, when applicable); (2) research institutes; (3) non-governmental organizations with primary contacts for information; (4) research and…

  19. Agricultural land for urban development : The process of land conversion in Central Vietnam

    NARCIS (Netherlands)

    Phuc, Nguyen Quang; Westen, A. C M van; Zoomers, Annelies

    Since the 1990s, Vietnam's progressive integration into the global market economy has triggered major economic and social transformations. In spatial terms, these are marked by a massive conversion of agricultural land for industrial and urban development. While this process has attracted

  20. Agricultural land for urban development: The process of land conversion in Central Vietnam

    NARCIS (Netherlands)

    Nguyen, C.P.; Westen, A.C.M. van; Zoomers, A.

    2014-01-01

    Since the 1990s, Vietnam’s progressive integration into the global market economy has triggered major economic and social transformations. In spatial terms, these are marked by a massive conversion of agricultural land for industrial and urban development. While this process has attracted

  1. Evidence of Mentor Learning and Development: An Analysis of New Zealand Mentor/Mentee Professional Conversations

    Science.gov (United States)

    Langdon, Frances J.

    2014-01-01

    While studies have shown that mentoring is essential to the development of new teachers, fewer investigations have examined what mentors learn about themselves and about mentoring through this role. In this study, the conversations between 13 mentors and their mentees were analysed, along with mentor self-evaluations and focus group data, over two…

  2. Rectenna System Design. [energy conversion solar power satellites

    Science.gov (United States)

    Woodcock, G. R.; Andryczyk, R. W.

    1980-01-01

    The fundamental processes involved in the operation of the rectenna system designed for the solar power satellite system are described. The basic design choices are presented based on the desired microwave rf field concentration prior to rectification and based on the ground clearance requirements for the rectenna structure. A nonconcentrating inclined planar panel with a 2 meter minimum clearance configuration is selected as a representative of the typical rectenna.

  3. Double barrier system for an in situ conversion process

    Science.gov (United States)

    McKinzie, Billy John [Houston, TX; Vinegar, Harold J [Bellaire, TX; Cowan, Kenneth Michael [Sugar land, TX; Deeg, Wolfgang Friedrich Johann [Houston, TX; Wong, Sau-Wai [Rijswijk, NL

    2009-05-05

    A barrier system for a subsurface treatment area is described. The barrier system includes a first barrier formed around at least a portion of the subsurface treatment area. The first barrier is configured to inhibit fluid from exiting or entering the subsurface treatment area. A second barrier is formed around at least a portion of the first barrier. A separation space exists between the first barrier and the second barrier.

  4. A comparison of energy conversion systems for meeting the power requirements of manned rover for Mars missions

    International Nuclear Information System (INIS)

    El-Genk, M.S.; Morley, N.; Cataldo, R.; Bloomfield, H.

    1990-01-01

    Minimizing system mass for interplanetary missions is of utmost importance in order to keep launch cost within reasonable bounds. For a manned Mars rover, powered by a nuclear reactor power system, the choice of the energy conversion system can play a significant role in lowering the overall system mass. Not only is the mass of the conversion unit affected by the choice, but also the masses of the reactor core, waste heat rejection system, and the radiation shield which are strongly influenced by the system conversion efficiency and operating condition. Several types of conversion systems are of interest for a nuclear reactor Mars manned application. These conversion systems include: free piston Stirling engines, He/XE closed Brayton cycle (CBC), CO 2 open Brayton, and SiGe/GaP thermoelectric. Optimization studies are conducted to determine the impact of the conversion system on the overall mass of the nuclear power system as well as the mobility power requirement of the Rover vehicle

  5. Towards ontology personalization to enrich social conversations on AAC systems

    Science.gov (United States)

    Mancilla V., Daniela; Sastoque H., Sebastian; Iregui G., Marcela

    2015-01-01

    Communication is one of the essential needs of human beings. Augmentative and Alternative Communication Systems (AAC) seek to help in the generation of oral and written language to people with physical disorders that limit their natural communication. These systems present significant challenges such as: the composition of consistent messages according to syntactic and semantic rules, the improvement of message production times, the application to social contexts and, consequently, the incorporation of user-specific information. This work presents an original ontology personalization approach for an AAC instant messaging system incorporating personalized information to improve the efficacy and efficiency of the message production. This proposal is based on a projection of a general ontology into a more specific one, avoiding storage redundancy and data coupling, representing a big opportunity to enrich communication capabilities of current AAC systems. The evaluation was performed for a study case based on an AAC system for assistance in composing messages. The results show that adding user-specific information allows generation of enriched phrases, so improving the accuracy of the message, facilitating the communication process.

  6. The use of conversation mapping to frame key perceptual issues facing the general dental practice system in England.

    Science.gov (United States)

    Harris, R V; Dancer, J M; Smith, D; Campbell, S

    2009-06-01

    To demonstrate the use of a novel qualitative methodology namely conversation mapping, which can be used to capture differences in stakeholder perspectives and give a root definition of the problem in a complex policy area. The methodology is used in the context of the changes introduced in the English general dental practice system in April 2006, to investigate the key issues facing the system, as perceived by general dental practitioners (GDPs). From a broad trigger statement, three transformational statements were produced. Each participant recorded their contribution on a hard diagrammatic form as a 'map', with others responding with their own written comment, thus generating three conversation maps. Thematic analysis resulted in the generation of a preliminary model summarising key perceptual issues. The five emergent themes identified were: financing, dentists' wants/needs, the role of the public and patients, system goals and policy level decision making. Financing was identified as the core category to which all other categories were related. Conversation mapping, a methodology arising from a systems approach, can be used to develop a 'rich picture' of an oral health care system in order to define the core problem within this policy area. Findings suggest that GDPs identify the financing of the system as a fundamental source of problems within the general dental practice system. This appears to be at variance with the perception of policy makers, who report a more limited view, identifying the system of remuneration as the 'heart of the problem'.

  7. A rationale plan for conversion of Malaysia for solar hydrogen energy system and its benefits

    International Nuclear Information System (INIS)

    Ludin, N.A.; Kamaruddin, W.N.; Kamaruzzaman Sopian; Verizoglu, T.N.

    2006-01-01

    It expected that early in the next century, Malaysia production of petroleum and natural gas will peak, and thereafter production will decline. In parallel with this production decline, Malaysia income from fossil fuels will start to decline, which would hurt the economy. One possible solution for Malaysia is the of Malaysia is the conversion to a hydrogen energy system. In order to move towards a sustainable hydrogen energy system, a future strategy must be outlined, followed, and continually revised. This paper will underline the available hydrogen technologies for production, storage, delivery, conversion, transportation and end use energy applications for the implementation of hydrogen energy system. Therefore, this paper will also emphasis the key success factors to drive the rationale plan for conversion to hydrogen energy system for Malaysia

  8. The conversion of smectite to illite in hydrothermal systems

    International Nuclear Information System (INIS)

    Johnston, R.M.

    1983-06-01

    In natural diagenetic shale systems, smectite converts to illite and mixed-layer illite-smectite in less than a million years at temperatures between 75 degrees C and 200 degrees C. This has raised questions as to the stability of smectite-based bentonite buffers under nuclear waste disposal vault conditions. Experimental and geological evidence indicate that the reaction is dependent on the availability of K + , and that the rate of reaction in K + -poor systems (such as the disposal vault) may be much lower than that observed in shale. The presence of Na + , Ca 2+ and Mg 2+ in the system slows the reaction and may halt it altogether at lower temperatures. Two different reaction mechanisms have been proposed; the evidence for, and implication of, each are discussed

  9. Limits to solar power conversion efficiency with applications to quantum and thermal systems

    Science.gov (United States)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1983-01-01

    An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

  10. Zeolite synthesis from the pyrrolidine containing system and their catalytic properties in the methanol conversion reaction

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kunio; Kiyozumi, Yoshimichi; Shin, Shigemitsu; Ogawa, Kiyoshi; Yamazaki, Yasuyoshi; Watanabe, Hideo

    1987-12-18

    Systhesis of zeolite from a system containing cheaper pyrrolidine as a crystallization regulator than quaternary ammonium ion was carried out and the methanol conversion reaction was studied over the systhesized zeolite to get C/sub 2/ and C/sub 3/ olefins. Hydrous gels were prepared by adding and agitating pyrrolidine, water glass and sulfuric acid to aluminum sulfate solution; and aluminum nitrate, colloidal silica and pyrrolidine to NaOH solution. Five zeolite, that is, ZSM-5, ZSM-35, ZSM-39, ZSM-48 and KZ-1 were synthesized by changing gel components. X-ray powder diffraction, BET specific surface areas, micropore diameters, micropore volumes, oxygen contents by scanning electron photomicrographs and infra-red spectra were examined. The organic base in hydrous gels influenced greatly on the zeolite composition and structure. The ZSM-5 zeolite exhibited the superior performance as to a high selectivity of light olefins over the target of development. (12 figs, 1 tab, 20 refs)

  11. Performance of a Kilowatt-Class Stirling Power Conversion System in a Thermodynamically-Coupled Configuration

    Science.gov (United States)

    Geng, S. M.; Briggs, M. H.; Hervol, D. S.

    A pair of 1kWe free-piston Stirling power convertors has been modified into a thermodynamically coupled configuration, and performance map testing has been completed. This is the same configuration planned for the full-scale 12 kWe power conversion unit (PCU) that will be used in the Fission Power System Technology Demonstration Unit (TDU). The 1-kWe convertors were operated over a range of conditions to evaluate the effects of thermodynamic coupling on convertor performance and to identify any possible control challenges. The thermodynamically coupled convertor showed no measurable difference in performance from the baseline data collected when the engines were separate and no major control issues were encountered during operation. The results of this test are guiding controller development and instrumentation selection for the TDU.

  12. Utilization of salt ammoniacates in fluidized beds in energy conversion thermochemical systems

    International Nuclear Information System (INIS)

    Romero, Jesus

    1984-01-01

    This research thesis notably reports the design and development of a thermochemical storage device involving equilibria of thermal decomposition of ammoniacates of strontium chlorides and calcium chloride in fluidized beds. The experimental study of this device allowed operating conditions and the most important concomitant effects of fluidization to be highlighted. The measured thermal exchange coefficient is about twenty times the measured value in equivalent devices using fixed beds. An irreversibility of the operation has been noticed, and seems to be associated with the irreversible change of grain size of solids. The author also reports a study of the properties of ammoniacates of metallic salts, and of the influence of fluidization on the performance of energy conversion thermochemical systems [fr

  13. Solar power conversion system with directionally- and spectrally-selective properties based on a reflective cavity

    Science.gov (United States)

    Boriskina, Svetlana; Kraemer, Daniel; McEnaney, Kenneth; Weinstein, Lee A.; Chen, Gang

    2018-03-13

    Solar power conversion system. The system includes a cavity formed within an enclosure having highly specularly reflecting in the IR spectrum inside walls, the enclosure having an opening to receive solar radiation. An absorber is positioned within the cavity for receiving the solar radiation resulting in heating of the absorber structure. In a preferred embodiment, the system further contains an energy conversion and storage devices thermally-linked to the absorber by heat conduction, convection, far-field or near-field thermal radiation.

  14. Chatbots as Conversational Recommender Systems in Urban Contexts

    OpenAIRE

    Kucherbaev, Pavel; Psyllidis, Achilleas; Bozzon, Alessandro

    2017-01-01

    In this paper, we outline the vision of chatbots that facilitate the interaction between citizens and policy-makers at the city scale. We report the results of a co-design session attended by more than 60 participants. We give an outlook of how some challenges associated with such chatbot systems could be addressed in the future.

  15. Research and development of utilization technology of solar thermal system for industrial and other use. Research and development of key technology (energy conversion on technology using chemical reactions); Sangyoyo nado solar system jitsuyoka gijutsu kaihatsu. Yoso gijutsu no kenkyu (kagaku energy henkan gijutsu no kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for energy conversion technology using chemical reactions by the aid of solar energy. The demonstration runs were conducted by a bench-scale unit, which was operated stably for 100h, to produce promising results. The catalyst exhibits stable performance, without showing a sign of deactivation. It is found that the heat pump system works well, without being interfered with accumulated by-products. A heat of approximately 2,100kcal/h is recovered. It is confirmed that steam of 150{degree}C and 200{degree}C is generated from hot water of 80{degree}C and 95{degree}C, respectively. The bench-scale runs show a thermal efficiency of around 10%, which is lower than the target level. However, the runs with hydrogen-occluding alloy attain a process thermal efficiency of 30%. The system in which solar collector and chemical heat pump units are combined is evaluated with respect to its economic efficiency and operability for its eventual commercialization. 6 figs., 2 tabs.

  16. Development of an integrated optimization method for analyzing effect of energy conversion efficiency under uncertainty – A case study of Bayingolin Mongol Autonomous Prefecture, China

    International Nuclear Information System (INIS)

    Jin, S.W.; Li, Y.P.; Huang, G.H.; Hao, Q.; Nie, S.

    2015-01-01

    Highlights: • Superiority–inferiority full-infinite mixed-integer method is developed. • The method can tackle uncertainties of fuzzy sets, crisp and functional intervals. • The method is applied to a real case of planning energy system. • Effects of energy-conversion efficiency on energy systems are analyzed. • Results can support policy enactment of conversion efficiency improvement. - Abstract: In this study, a superiority–inferiority full-infinite mixed-integer programming (SFMP) method is developed for analyzing the effect of energy conversion efficiency under uncertainty. SFMP can effectively tackle uncertainties expressed as fuzzy sets, crisp intervals and functional intervals, it also can directly reflect relationships among multiple fuzzy sets through varying superiority and inferiority degrees with a high computational efficiency. Then the developed SFMP is applied to a real case of planning energy system for Bayingolin Mongol Autonomous Prefecture, where multiple scenarios related to different energy-conversion efficiency are concerned. Results for energy processing, energy conversion, capacity expansion, pollutant emission and system cost have been generated. It is proved that SFMP is an effective approach to deal with the uncertainties in energy systems with interactive and uncertain characteristics. A variety of uncertainties existed in energy conversion processes and impact factors could affect the modeling result. Results show that improvement of energy-conversion efficiency can effectively facilitate reducing energy resources consumption, optimizing energy generation pattern, decreasing capacity expansion, as well as mitigating pollutant emissions. Results also reveal that, for the study area, electric power has a highest energy saving potential among heating, oil processing, coal washing and refining. Results can help decision makers to generate desired alternatives that can facilitate policy enactment of conversion efficiency

  17. Evaluation for reasonableness of power conversion system concepts in the gas turbine high temperature reactor (GTHTR300)

    International Nuclear Information System (INIS)

    Minatsuki, I.; Mizokami, Y.

    2007-01-01

    The conceptual design study for the Gas Turbine High Temperature Reactor (GTHTR300) was completed in 2004. In GTHTR300, SECO (Simple, Economical Competitiveness and Originality) is advocated as design philosophy in order to minimize technical and economical requirement. Furthermore the design of the GTHTR300 was developed with reflecting various view points from utilities, manufacturers and research organizations. In GTHTR300, the horizontal turbo machine rotor, the turbo machine in a separated vessel, the turbo machine with single rotor, the generator inside the power conversion vessel, and the power conversion system without inter-coolers were selected as major power conversion system concepts. This paper describes the investigation and analysis about the major concepts of GTHTR300 power conversion system in order to evaluate reasonableness of GTHTR300 design approach and acceptability with using experience and engineering knowledge of Mitsubishi Heavy Industries, Ltd., which were accumulated through the activities of HTGR-GT and HTTR (High Temperature Engineering Test Reactor) designing, manufacturing, fabricating and testing. From the result of the evaluation, it was concluded that the selection of each concept in GTHTR300 was reasonable as based on the original design philosophy SECO. As a conclusion, we expect the GTHTR300 to become one of the most promising concepts for commercialization in near future. (authors)

  18. Microchemical Systems for Fuel Processing and Conversion to Electrical Power

    Science.gov (United States)

    2007-03-15

    Models As a case study for the optimization of a fixed process structures an ammonia cracking based process, using butane catalytic combustion for...microreactor system. Future studies will involve the optimization of the microreactor design and catalyst loading to obtain a controlled autothermal...Figure 44: XRD patterns for ( a ) Ni-Sn/YSZ cermet prepared by reduction of the oxide composite, and (b) Ni- Sn/YSZ cermet and (c) Ni/YSZ cermet

  19. Successive approximation analog to digital conversion system with good differential linearity

    Energy Technology Data Exchange (ETDEWEB)

    Carter, D E; Randers-Pehrson, G [Ohio Univ., Athens (USA). Dept. of Physics

    1982-08-15

    A high speed modified successive approximation 4 input ADC system has been designed and constructed. Throughput rates of 250 kHz at 12 bit conversion gain with good differential linearity is achieved at low cost, using the MPX4 ADC system.

  20. Expanding Learning and Social Interaction through Intelligent Systems Design: Implementing a Reputation and Recommender System for the Claremont Conversation Online

    Science.gov (United States)

    Thoms, Brian

    2009-01-01

    In this dissertation I examine the design, construction and implementation of an online blog ratings and user recommender system for the Claremont Conversation Online (CCO). In line with constructivist learning models and practical information systems (IS) design, I implemented a blog ratings system (a system that can be extended to allow for…

  1. Sperry Low Temperature Geothermal Conversion System, Phase 1 and Phase 2. Volume 3: Systems description

    Science.gov (United States)

    Matthews, H. B.

    The major fraction of hydrothermal resources with the prospect of economic usefulness for the generation of electricity are in the 300(0)F to 425(0)F temperature range. Cost effective conversion of the geothermal energy to electricity requires new ideas to improve conversion efficiency, enhance brine flow, reduce plant costs, increase plant availability, and shorten the time between investment and return. The problems addressed are those inherent in the geothermal environment, in the binary fluid cycle, in the difficulty of efficiently converting the energy of a low temperature resource, and in geothermal economics some of these problems are explained. The energy expended by the down hole pump; the difficulty in designing reliable down hole equipment; fouling of heat exchanger surfaces by geothermal fluids; the unavailability of condenser cooling water at most geothermal sites; the large portion of the available energy used by the feed pump in a binary system; the pinch effect, a loss in available energy in transferring heat from water to an organic fluid; flow losses in fluids that carry only a small amount of useful energy to begin with; high heat exchanger costs, the lower the temperature interval of the cycle, the higher the heat exchanger costs in $/kW; the complexity and cost of the many auxiliary elements of proposed geothermal plants; and the unfortunate cash flow vs. investment curve caused by the many years of investment required to bring a field into production before any income is realized.

  2. HVDC transmission power conversion applications in power systems

    CERN Document Server

    Kim, Chan-Ki; Jang, Gil-Soo; Lim, Seong-Joo; Lee, Seok-Jin

    2009-01-01

    HVDC is a critical solution to several major problems encountered when trying to maintain systemic links and quality in large-scale renewable energy environments. HDVC can resolve a number of issues, including voltage stability of AC power networks, reducing fault current, and optimal management of electric power, ensuring the technology will play an increasingly important role in the electric power industry. To address the pressing need for an up-to-date and comprehensive treatment of the subject, Kim, Sood, Jang, Lim and Lee have collaborated to produce this key text and reference.  Combin

  3. Research and evaluation of biomass resources/conversion/utilization systems. Biomass allocation model. Volume 1: Test and appendices A & B

    Science.gov (United States)

    Stringer, R. P.; Ahn, Y. K.; Chen, H. T.; Helm, R. W.; Nelson, E. T.; Shields, K. J.

    1981-08-01

    A biomass allocation model was developed to show the most profitable combination of biomass feedstocks, thermochemical conversion processes, and fuel products to serve the seasonal conditions in a regional market. This optimization model provides a tool for quickly calculating which of a large number of potential biomass missions is the most profitable mission. Other components of the system serve as a convenient storage and retrieval mechanism for biomass marketing and thermochemical conversion processing data. The system can be accessed through the use of a computer terminal, or it could be adapted to a microprocessor. A User's Manual for the system is included. Biomass derived fuels included in the data base are the following: medium Btu gas, low Btu gas, substitute natural gas, ammonia, methanol, electricity, gasoline, and fuel oil.

  4. Catalytic conversion of corncob and corncob pretreatment hydrolysate to furfural in a biphasic system with addition of sodium chloride.

    Science.gov (United States)

    Qing, Qing; Guo, Qi; Zhou, Linlin; Wan, Yilun; Xu, Youqing; Ji, Huilong; Gao, Xiaohang; Zhang, Yue

    2017-02-01

    Catalytic conversion of corncob pretreatment hydrolysate and raw corncob into furfural in a modified biphasic system by SO 4 2- /SnO 2 - MMT solid catalyst has been developed. The influence of the organic solvent type, organic to water phase ratio, sodium chloride concentration, reaction temperature and time on the furfural production were comparatively evaluated. The results showed that furfural yields of 81.7% and 66.1% were achieved at 190°C for 15mins and 190°C for 20mins, respectively, for corncob pretreatment hydrolysate and raw corncob by this solid catalyst. The solid catalyst used in this study exhibited good stability and high efficiency applied in the modified biphasic system in addition to excellent recyclability. The proposed catalytic system displayed high performance for catalytic conversion of lignocellulosic biomass into important platform chemicals and has great potential in industrial application. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Feedstock and Conversion Supply System Design and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mohammad, R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cafferty, K. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kenney, K. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Searcy, E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hansen, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    The success of the earlier logistic pathway designs (Biochemical and Thermochemical) from a feedstock perspective was that it demonstrated that through proper equipment selection and best management practices, conventional supply systems (referred to in this report as “conventional designs,” or specifically the 2012 Conventional Design) can be successfully implemented to address dry matter loss, quality issues, and enable feedstock cost reductions that help to reduce feedstock risk of variable supply and quality and enable industry to commercialize biomass feedstock supply chains. The caveat of this success is that conventional designs depend on high density, low-cost biomass with no disruption from incremental weather. In this respect, the success of conventional designs is tied to specific, highly productive regions such as the southeastern U.S. which has traditionally supported numerous pulp and paper industries or the Midwest U.S for corn stover.

  6. Open cycle ocean thermal energy conversion system structure

    Science.gov (United States)

    Wittig, J. Michael

    1980-01-01

    A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially situated in the mushroom's stem portion. Upon expansion through the turbine, the motive steam enters a shell and tube condenser annularly disposed about the rotor axis and axially situated beneath the turbine in the stem portion. Relatively warm ocean water is circulated up through the radially outer skirt-conduit structure entering the evaporator through a radially outer portion thereof, flashing a portion thereof into motive steam, and draining the unflashed portion from the evaporator through a radially inner skirt-conduit structure. Relatively cold cooling water enters the annular condenser through the radially inner edge and travels radially outwardly into a channel situated along the radially outer edge of the condenser. The channel is also included in the radially inner skirt-conduit structure. The cooling water is segregated from the potable, motive steam condensate which can be used for human consumption or other processes requiring high purity water. The expansion energy of the motive steam is partially converted into rotational mechanical energy of the turbine rotor when the steam is expanded through the shaft attached blades. Such mechanical energy drives a generator also included in the enlarged mushroom portion for producing electrical energy. Such power generation equipment arrangement provides a compact power system from which additional benefits may be obtained by fabricating the enclosing equipment, housings and component casings from low density materials, such as prestressed concrete, to permit those casings and housings to also function as a floating

  7. Formalization of hydrocarbon conversion scheme of catalytic cracking for mathematical model development

    Science.gov (United States)

    Nazarova, G.; Ivashkina, E.; Ivanchina, E.; Kiseleva, S.; Stebeneva, V.

    2015-11-01

    The issue of improving the energy and resource efficiency of advanced petroleum processing can be solved by the development of adequate mathematical model based on physical and chemical regularities of process reactions with a high predictive potential in the advanced petroleum refining. In this work, the development of formalized hydrocarbon conversion scheme of catalytic cracking was performed using thermodynamic parameters of reaction defined by the Density Functional Theory. The list of reaction was compiled according to the results of feedstock structural-group composition definition, which was done by the n-d-m-method, the Hazelvuda method, qualitative composition of feedstock defined by gas chromatography-mass spectrometry and individual composition of catalytic cracking gasoline fraction. Formalized hydrocarbon conversion scheme of catalytic cracking will become the basis for the development of the catalytic cracking kinetic model.

  8. Environmental performance assessment of utility boiler energy conversion systems

    International Nuclear Information System (INIS)

    Li, Changchun; Gillum, Craig; Toupin, Kevin; Park, Young Ho; Donaldson, Burl

    2016-01-01

    Highlights: • Sustainability analyses of utility boilers are performed. • Natural gas fired boilers have the least CO_2 emissions in fossil fueled boilers. • Solar boilers rank last with an emergy yield ratio of 1.2. • Biomass boilers have the best emergy sustainability index. - Abstract: A significant amount of global electric power generation is produced from the combustion of fossil fuels. Steam boilers are one of the most important components for steam and electricity production. The objective of this paper is to establish a theoretical framework for the sustainability analysis of a utility boiler. These analyses can be used by decision-makers to diagnose and optimize the sustainability of a utility boiler. Seven utility boiler systems are analyzed using energy and embodied solar energy (emergy) principles in order to evaluate their environmental efficiencies. They include a subcritical coal fired boiler, a supercritical coal fired boiler, an oil fired boiler, a natural gas fired boiler, a concentrating solar power boiler utilizing a tower configuration, a biomass boiler, and a refuse derived fuel boiler. Their relative environmental impacts were compared. The results show that the natural gas boiler has significantly lower CO_2 emission than an equivalent coal or oil fired boiler. The refuse derived fuel boiler has about the same CO_2 emissions as the natural gas boiler. The emergy sustainability index of a utility boiler system is determined as the measure of its sustainability from an environmental perspective. Our analyses results indicate that the natural gas boiler has a relatively high emergy sustainability index compared to other fossil fuel boilers. Converting existing coal boilers to natural gas boilers is a feasible option to achieve better sustainability. The results also show that the biomass boiler has the best emergy sustainability index and it will remain a means to utilize the renewable energy within the Rankine steam cycle. Before

  9. Study of a wind energy conversion system in New Hampshire

    Science.gov (United States)

    Lockwood, J.; Kraft, G.; Pregent, G.; Smukler, L.

    1981-08-01

    Concern over conventional energy costs and supplies is currently strong, particularly in New England region where eighty percent of the total energy is oil based; furthermore, forty percent of this region's total energy is OPEC oil. These figures contrast with national averages of forty-seven and thirteen percent, respectively (1). The quest to develop alternative and renewable energy sources indigenous to New England is understandable in light of these figures. The wind is one such source. The study of wind energy can be divided into three basic areas; these are technical, legal-institutional, and financial. The technical area encompasses collection and analysis of wind data, selection and installation of wind turbines and peripheral equipment, and operation and maintenance. The legal-institutional area encompasses the resolution of such issues as land use policies, power contracts, and state and federal regulations. The financial area encompasses the examination of investment opportunities made available by various site-machine combinations and the selling of such opportunities to the investment community.

  10. Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil [' ' Dunarea de Jos' ' University of Galati, 47, Domneasca, 800008-Galati (Romania)

    2010-02-15

    This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results. (author)

  11. Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

    International Nuclear Information System (INIS)

    Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil

    2010-01-01

    This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results.

  12. Conversations about mental states and theory of mind development during middle childhood: A training study.

    Science.gov (United States)

    Bianco, Federica; Lecce, Serena; Banerjee, Robin

    2016-09-01

    Despite 30years of productive research on theory of mind (ToM), we still know relatively little about variables that influence ToM development during middle childhood. Recent experimental studies have shown that conversations about the mind affect ToM abilities, but they have not explored the mechanisms underlying this developmental effect. In the current study, we examined two potential mechanisms through which conversations about mental states are likely to influence ToM: an increased frequency of references to mental states when explaining behavior and an increased accuracy of mental-state attributions. To this aim, we conducted a training study in which 101 children were assigned to either an intervention condition or a control condition. The conversation-based intervention was made up of four sessions scheduled over 2weeks. Children completed a battery of assessments before and after the intervention as well as 2months later. The groups were equivalent at Time 1 (T1) for age, family affluence, vocabulary, and executive functions. The ToM group showed an improvement in ToM skills (as evaluated on both the practiced tasks and a transfer task). Mediation analyses demonstrated that the accuracy of mental-state attributions, but not the mere frequency of mental-state references, mediated the positive effect of conversations about the mind on ToM development. Our results indicate that conversational experience can enhance mental-state reasoning not by simply drawing children's attention to mental states but rather by scaffolding a mature understanding of social situations. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. On the conversion of dose to bone to dose to water in radiotherapy treatment planning systems

    Directory of Open Access Journals (Sweden)

    Nick Reynaert

    2018-01-01

    Full Text Available Background and purpose: Conversion factors between dose to medium (Dm,m and dose to water (Dw,w provided by treatment planning systems that model the patient as water with variable electron density are currently based on stopping power ratios. In the current paper it will be illustrated that this conversion method is not correct. Materials and methods: Monte Carlo calculations were performed in a phantom consisting of a 2 cm bone layer surrounded by water. Dw,w was obtained by modelling the bone layer as water with the electron density of bone. Conversion factors between Dw,w and Dm,m were obtained and compared to stopping power ratios and ratios of mass-energy absorption coefficients in regions of electronic equilibrium and interfaces. Calculations were performed for 6 MV and 20 MV photon beams. Results: In the region of electronic equilibrium the stopping power ratio of water to bone (1.11 largely overestimates the conversion obtained using the Monte Carlo calculations (1.06. In that region the MC dose conversion corresponds to the ratio of mass energy absorption coefficients. Near the water to bone interface, the MC ratio cannot be determined from stopping powers or mass energy absorption coefficients. Conclusion: Stopping power ratios cannot be used for conversion from Dm,m to Dw,w provided by treatment planning systems that model the patient as water with variable electron density, either in regions of electronic equilibrium or near interfaces. In regions of electronic equilibrium mass energy absorption coefficient ratios should be used. Conversions at interfaces require detailed MC calculations. Keywords: Dose to water, Monte Carlo, Dosimetry, TPS comparison

  14. Simulating the conversion of rural settlements to town land based on multi-agent systems and cellular automata.

    Science.gov (United States)

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans.

  15. Simulating the Conversion of Rural Settlements to Town Land Based on Multi-Agent Systems and Cellular Automata

    Science.gov (United States)

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans. PMID:24244472

  16. Fiscal 1994 achievement report. Development of photovoltaic power generation system practicalization technology - Development of ultrahigh-efficiency solar cell technology (Development of new photoelectric conversion material technology - Research on future feasibility of wet-type solar cells); Taiyoko hatsuden system jitsuyoka gijutsu kaihatsu. Chokokoritsu taiyo denchi no gijutsu kaihatsu (shinkoden henkan zairyo no gijutsu kaihatsu (shisshiki taiyo denchi no shoraiteki kanosei no chosa))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    A survey is conducted of wet-type solar cells that may constitute an important field in solar chemistry. The wet type solar cell made known by Graetzel et al. in 1991 is a combination of ultrafine TiO{sub 2} grains and a sensitizing dye. The ultrafine grain surface structure enlarges the area of an electrode for the absorption of 46% of incident solar radiation of which 80% or more is converted into electric power. The fill factor at 520nm of a cell fabricated for an additional test turns out to be 40% against the 76% mentioned in technical literature, and the conversion efficiency 10%. The Titanyl sulfate is also tested because it is low in price as material for titanium oxide. Functional groups are experimentally introduced for the generation of bonds on the substrate to be effective in the injection of a sensitizing dye. A sensitizing dye with two carboxyl groups and two bipyridine rings as ligand is allowed to be supported by TiO{sub 2}. IR (infrared) spectrometry is performed, and then formation is found of ester-like bonds or chelate bonds due to the interaction of carboxyl groups and the substrate surface. This is enhanced by surface treatment. (NEDO)

  17. Measurements of Conversion Efficiency for a Flat Plate Thermophotovoltaic System Using a Photonic Cavity Test System

    International Nuclear Information System (INIS)

    Brown, E.J.; Ballinger, C.T.; Burger, S.R.; Charache, G.W.; Danielson, L.R.; DePoy, D.M.; Donovan, T.J.; LoCascio, M.

    2000-01-01

    The performance of a 1 cm 2 thermophotovoltaic (TPV) module was recently measured in a photonic cavity test system. A conversion efficiency of 11.7% was measured at a radiator temperature of 1076 C and a module temperature of 29.9 C. This experiment achieved the highest direct measurement of efficiency for an integrated TPV system. Efficiency was calculated from the ratio of the peak (load matched) electrical power output and the heat absorption rate. Measurements of these two parameters were made simultaneously to assure the validity of the measured efficiency value. This test was conducted in a photonic cavity which mimicked a typical flat-plate TPV system. The radiator was a large, flat graphite surface. The module was affixed to the top of a copper pedestal for heat absorption measurements. The heat absorption rate was proportional to the axial temperature gradient in the pedestal under steady-state conditions. The test was run in a vacuum to eliminate conductive and convective heat transfer mechanisms. The photonic cavity provides the optimal test environment for TPV efficiency measurements because it incorporates all important physical phenomena found in an integrated TPV system: high radiator emissivity and blackbody spectral shape, photon recycling, Lambertian distribution of incident radiation and complex geometric effects. Furthermore, the large aspect ratio between radiating surface area and radiator/module spacing produces a view factor approaching unity with minimal photon leakage

  18. A platform for development and evaluation of real - time wind energy conversion strategies

    International Nuclear Information System (INIS)

    Toccaceli, G; Cendoya, M; Battaiotto, P

    2005-01-01

    Wind energy is one of the most promising power generation alternatives, and one of the most dynamic scenarios for novel control strategies. The particular characteristics of each geographical zone, and the inherent randomness of the wind impose important constrains for the evaluation of a wind energy conversion system (WECS). This is particularly true for wind turbines and their associated instrumentation. A wind turbine emulator (WTE) can be used to help in the evaluation of hardware-software alternatives, avoiding difficult field tests by recreating real environments on a controlled testbed. It consists of an electrical machine driven by a solid-state converter. WTEs are controlled to provide a desired dynamic Torque-Speed characteristic, equivalent to a real wind turbine under prescribed external conditions. The control system provides a desired torque value as a function of wind and turbine shaft speeds. This work presents the hardware / software development of a WECS emulator to be used in analysis and design of Real-Time control strategies for different types of electric generators. The proposed system is composed by a wind turbine emulator connected to an AC generator. The Wind Turbine Emulator consists of a direct current (DC) motor that is driven by a four-quadrant DC/DC converter or chopper. It is made of a MOSFET H-Bridge, with a current control loop. The generator block consists of an asynchronous AC machine, driven by static converters tailored to particular applications (autonomous or grid-connected WECS).With the objective to have a versatile system, the control of WTE and WECS generator is carried out by a Pentium PC equipped with an I/O multifunction acquisition board. It generates reference values for the current control loop driving the chopper and measures the shaft rotation speed using an incremental optical encoder. Software for the PC is developed in MatLab/Simulink, using Real Time WorkShop (RTW) and Real Time Windows Target (RTWT). This

  19. A theoretical analysis of price elasticity of energy demand in multistage energy conversion systems

    International Nuclear Information System (INIS)

    Lowe, R.

    2003-01-01

    The objective of this paper is an analytical exploration of the problem of price elasticity of energy demand in multi-stage energy conversion systems. The paper describes in some detail an analytical model of energy demand in such systems. Under a clearly stated set of assumptions, the model makes it possible to explore both the impacts of the number of sub-systems, and of varying sub-system elasticities on overall system elasticity. The analysis suggests that overall price elasticity of energy demand for such systems will tend asymptotically to unity as the number of sub-systems increases. (author)

  20. A theoretical analysis of price elasticity of energy demand in multi-stage energy conversion systems

    International Nuclear Information System (INIS)

    Lowe, Robert

    2003-01-01

    The objective of this paper is an analytical exploration of the problem of price elasticity of energy demand in multi-stage energy conversion systems. The paper describes in some detail an analytical model of energy demand in such systems. Under a clearly stated set of assumptions, the model makes it possible to explore both the impacts of the number of sub-systems, and of varying sub-system elasticities on overall system elasticity. The analysis suggests that overall price elasticity of energy demand for such systems will tend asymptotically to unity as the number of sub-systems increases

  1. Autistic traits and brain activation during face-to-face conversations in typically developed adults.

    Science.gov (United States)

    Suda, Masashi; Takei, Yuichi; Aoyama, Yoshiyuki; Narita, Kosuke; Sakurai, Noriko; Fukuda, Masato; Mikuni, Masahiko

    2011-01-01

    Autism spectrum disorders (ASD) are characterized by impaired social interaction and communication, restricted interests, and repetitive behaviours. The severity of these characteristics is posited to lie on a continuum that extends into the general population. Brain substrates underlying ASD have been investigated through functional neuroimaging studies using functional magnetic resonance imaging (fMRI). However, fMRI has methodological constraints for studying brain mechanisms during social interactions (for example, noise, lying on a gantry during the procedure, etc.). In this study, we investigated whether variations in autism spectrum traits are associated with changes in patterns of brain activation in typically developed adults. We used near-infrared spectroscopy (NIRS), a recently developed functional neuroimaging technique that uses near-infrared light, to monitor brain activation in a natural setting that is suitable for studying brain functions during social interactions. We monitored regional cerebral blood volume changes using a 52-channel NIRS apparatus over the prefrontal cortex (PFC) and superior temporal sulcus (STS), 2 areas implicated in social cognition and the pathology of ASD, in 28 typically developed participants (14 male and 14 female) during face-to-face conversations. This task was designed to resemble a realistic social situation. We examined the correlations of these changes with autistic traits assessed using the Autism-Spectrum Quotient (AQ). Both the PFC and STS were significantly activated during face-to-face conversations. AQ scores were negatively correlated with regional cerebral blood volume increases in the left STS during face-to-face conversations, especially in males. Our results demonstrate successful monitoring of brain function during realistic social interactions by NIRS as well as lesser brain activation in the left STS during face-to-face conversations in typically developed participants with higher levels of autistic

  2. Situation and perspectives of the development of investigation on photovoltage conversion of solar energy in Kazakhstan

    International Nuclear Information System (INIS)

    Mansurov, Z.A.; Taurbaev, T.I.; Mikhailov, L.V.; Bychkov, S.G.

    1997-01-01

    The article presents the talk on the research and development on photovoltaic conversion of solar energy in Kazakhstan given at the International Workshop on applied solar energy held in Tashkent(Uzbekistan) in June 1997. It is shown that the use of solar energy devices in particular on the basis of photovoltaic cells has the economical advantage in Kazakhstan arid lands. The description of some photovoltaic cells on the basis of aluminium and gallium arsenide is presented. (A.A.D.)

  3. Hybrid Intelligent Control Method to Improve the Frequency Support Capability of Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Shin Young Heo

    2015-10-01

    Full Text Available This paper presents a hybrid intelligent control method that enables frequency support control for permanent magnet synchronous generators (PMSGs wind turbines. The proposed method for a wind energy conversion system (WECS is designed to have PMSG modeling and full-scale back-to-back insulated-gate bipolar transistor (IGBT converters comprising the machine and grid side. The controller of the machine side converter (MSC and the grid side converter (GSC are designed to achieve maximum power point tracking (MPPT based on an improved hill climb searching (IHCS control algorithm and de-loaded (DL operation to obtain a power margin. Along with this comprehensive control of maximum power tracking mode based on the IHCS, a method for kinetic energy (KE discharge control of the supporting primary frequency control scheme with DL operation is developed to regulate the short-term frequency response and maintain reliable operation of the power system. The effectiveness of the hybrid intelligent control method is verified by a numerical simulation in PSCAD/EMTDC. Simulation results show that the proposed approach can improve the frequency regulation capability in the power system.

  4. Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

    Science.gov (United States)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990's.

  5. Design and Fabrication of a 5-kWe Free-Piston Stirling Power Conversion System

    Science.gov (United States)

    Chapman, Peter A.; Walter, Thomas J.; Brandhorst, Henry W., Jr.

    2008-01-01

    Progress in the design and fabrication of a 5-kWe free-piston Stirling power conversion system is described. A scaled-down version of the successful 12.5-kWe Component Test Power Converter (CTPC) developed under NAS3-25463, this single cylinder prototype incorporates cost effective and readily available materials (steel versus beryllium) and components (a commercial linear alternator). The design consists of a displacer suspended on internally pumped gas bearings and a power piston/alternator supported on flexures. Non-contacting clearance seals are used between internal volumes. Heat to and from the prototype is supplied via pumped liquid loops passing through shell and tube heat exchangers. The control system incorporates several novel ideas such as a pulse start capability and a piston stroke set point control strategy that provides the ability to throttle the engine to match the required output power. It also ensures stable response to various disturbances such as electrical load variations while providing useful data regarding the position of both power piston and displacer. All design and analysis activities are complete and fabrication is underway. Prototype test is planned for summer 2008 at Foster-Miller to characterize the dynamics and steady-state operation of the prototype and determine maximum power output and system efficiency. Further tests will then be performed at Auburn University to determine start-up and shutdown characteristics and assess transient response to temperature and load variations.

  6. Computational analysis of supercritical CO2 Brayton cycle power conversion system for fusion reactor

    International Nuclear Information System (INIS)

    Halimi, Burhanuddin; Suh, Kune Y.

    2012-01-01

    Highlights: ► Computational analysis of S-CO 2 Brayton cycle power conversion system. ► Validation of numerical model with literature data. ► Recompression S-CO 2 Brayton cycle thermal efficiency of 42.44%. ► Reheating concept to enhance the cycle thermal efficiency. ► Higher efficiency achieved by the proposed concept. - Abstract: The Optimized Supercritical Cycle Analysis (OSCA) code is being developed to analyze the design of a supercritical carbon dioxide (S-CO 2 ) driven Brayton cycle for a fusion reactor as part of the Modular Optimal Balance Integral System (MOBIS). This system is based on a recompression Brayton cycle. S-CO 2 is adopted as the working fluid for MOBIS because of its easy availability, high density and low chemical reactivity. The reheating concept is introduced to enhance the cycle thermal efficiency. The helium-cooled lithium lead model AB of DEMO fusion reactor is used as reference in this paper.

  7. Converse Barrier Certificate Theorems

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2016-01-01

    This paper shows that a barrier certificate exists for any safe dynamical system. Specifically, we prove converse barrier certificate theorems for a class of structurally stable dynamical systems. Other authors have developed a related result by assuming that the dynamical system has neither...

  8. U-AVLIS feed conversion using continuous metallothermic reduction of UF4: System description and cost estimate

    International Nuclear Information System (INIS)

    1994-04-01

    The purpose of this document is to present a system description and develop baseline capital and operating cost estimates for commercial facilities which produced U-Fe feedstock for AVLIS enrichment plants using the continuous fluoride reduction (CFR) process. These costs can then be used together with appropriate economic assumptions to calculate estimated unit costs to the AVLIS plant owner (or utility customer) for such conversion services. Six cases are being examined. All cases assume that the conversion services are performed by a private company at a commercial site which has an existing NRC license to possess source material and which has existing uranium processing operations. The cases differ in terms of annual production capacity and whether the new process system is installed in a new building or in an existing building on the site. The six cases are summarized here

  9. U-AVLIS feed conversion using continuous metallothermic reduction of UF{sub 4}: System description and cost estimate

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-01

    The purpose of this document is to present a system description and develop baseline capital and operating cost estimates for commercial facilities which produced U-Fe feedstock for AVLIS enrichment plants using the continuous fluoride reduction (CFR) process. These costs can then be used together with appropriate economic assumptions to calculate estimated unit costs to the AVLIS plant owner (or utility customer) for such conversion services. Six cases are being examined. All cases assume that the conversion services are performed by a private company at a commercial site which has an existing NRC license to possess source material and which has existing uranium processing operations. The cases differ in terms of annual production capacity and whether the new process system is installed in a new building or in an existing building on the site. The six cases are summarized here.

  10. Technical evaluation of Aerojet Energy Conversion Company's topical report on a mobile volume reduction system

    International Nuclear Information System (INIS)

    Henscheid, J.W.

    1984-01-01

    This report summarizes EG and G Idaho's review of Aerojet Energy Conversion Company's (AECC's) topical report on a Mobile Volume Reduction System. The review evaluated compliance with pertinent codes, standards and regulations. The initial review was discussed with AECC by EG and G Idaho and the NRC, and all outstanding issues resolved before this final evaluation was made

  11. Dynamic modelling and robust control of a wind energy conversion system

    NARCIS (Netherlands)

    Steinbuch, M.

    1989-01-01

    The application of wind energy conversion systems for the production of electrical energy requires a cheap and reliable operation. Especially at high wind velocities fluctuations from the wind field result in large mechanical loads of the wind turbine. Also fluctuations in the grid voltage may yield

  12. Understanding Power Electronics and Electrical Machines in Multidisciplinary Wind Energy Conversion System Courses

    Science.gov (United States)

    Duran, M. J.; Barrero, F.; Pozo-Ruz, A.; Guzman, F.; Fernandez, J.; Guzman, H.

    2013-01-01

    Wind energy conversion systems (WECS) nowadays offer an extremely wide range of topologies, including various different types of electrical generators and power converters. Wind energy is also an application of great interest to students and with a huge potential for engineering employment. Making WECS the main center of interest when teaching…

  13. Direct Student Loans: Overpayments during the Department of Education's Conversion to a New Payment System.

    Science.gov (United States)

    Joyner, Carlotta C.

    This report addresses concerns that the Department of Education may have erroneously made overpayments of as much as $400 million to schools participating in the William D. Ford Federal Direct Loan Program (FDLP) during the Department's conversion to a new computerized payment system. The investigation found that because the transition to the new…

  14. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...

  15. A methodological framework for the development of feasible CO2 conversion processes

    DEFF Research Database (Denmark)

    Roh, Kosan; Lee, Jay H.; Gani, Rafiqul

    2016-01-01

    combined reforming (CR) of methane reaction is developed. To supply the CO2 feedstock, the aMDEA-based CO2 capture applied to a SMR-based H2 plant is considered. A baseline process is developed and is compared with a non-CO2 utilizing conventional methanol plant (process substitution) and a gasoline...... that the feasibility of the CO2-based methanol as an alternative fuel to gasoline highly depends on the type and price of the raw materials. To improve the developed baseline CO2 conversion process further, (1) some of the combined reforming reaction related design variables are fine-tuned using a sensitivity analysis...

  16. An optimized power conversion system concept of the integral, inherently-safe light water reactor

    International Nuclear Information System (INIS)

    Memmott, Matthew J.; Wilding, Paul R.; Petrovic, Bojan

    2017-01-01

    Highlights: • Three power conversion systems (PCS) for the I"2S-LWR are presented. • An optimization analyses was performed to evaluate these PCS alternatives. • The ideal PCS consists of 5 turbines, and obtains an overall efficiency of 35.7%. - Abstract: The integral, inherently safe light water reactor (I"2S-LWR) has been developed to significantly enhance passive safety capabilities while maintaining cost competitiveness relative to the current light water reactor (LWR) fleet. The compact heat exchangers of the I"2S-LWR preclude boiling of the secondary fluid, which decreases the probability of heat exchanger failure, but this requires the addition of a flash drum, which negatively affects the overall plant thermodynamic efficiency. A state of the art Rankine cycle is proposed for the I"2S-LWR to increase the thermodynamic efficiency by utilizing a flash drum with optimized operational parameters. In presenting this option for power conversion in the I"2S-LWR power plant, the key metric used in rating the performance is the overall net thermodynamic efficiency of the cycle. In evaluating the flash-Rankine cycle, three basic industrial concepts are evaluated, one without an intermediate pressure turbine, one with an intermediate turbine and one reheat stream, and one with an intermediate turbine and two reheat streams. For each configuration, a single-path multi-variable optimization is undertaken to maximize the thermal efficiency. The third configuration with an intermediate turbine and 2 reheat streams is the most effective concept, with an optimized efficiency of 35.7%.

  17. Robust Sliding Mode Control of Permanent Magnet Synchronous Generator-Based Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Guangping Zhuo

    2016-12-01

    Full Text Available The subject of this paper pertains to sliding mode control and its application in nonlinear electrical power systems as seen in wind energy conversion systems. Due to the robustness in dealing with unmodeled system dynamics, sliding mode control has been widely used in electrical power system applications. This paper presents first and high order sliding mode control schemes for permanent magnet synchronous generator-based wind energy conversion systems. The application of these methods for control using dynamic models of the d-axis and q-axis currents, as well as those of the high speed shaft rotational speed show a high level of efficiency in power extraction from a varying wind resource. Computer simulation results have shown the efficacy of the proposed sliding mode control approaches.

  18. Collaborative role construction in a conversation with dementia: an application of systemic functional linguistics.

    Science.gov (United States)

    Müller, Nicole; Wilson, Brent T

    2008-01-01

    This study applies the tools provided by Systemic Functional Linguistics (SFL) to the description of patterns in a conversation between a person with dementia and a person without. It shows how, in the presence of, on the one hand, considerable communicative and cognitive deficits, and on the other, a collaborative interlocutor, a person with dementia succeeds in leading and sustaining a lengthy conversation, and of constructing for himself a positive role in the interaction, namely that of the elder advising a much younger man.

  19. Experimental-demonstrative system for energy conversion using hydrogen fuel cell - preliminary results

    International Nuclear Information System (INIS)

    Stoenescu, D.; Stefanescu, I.; Patularu, I.; Culcer, M.; Lazar, R.E.; Carcadea, E.; Mirica, D. . E-mail address of corresponding author: daniela@icsi.ro; Stoenescu, D.)

    2005-01-01

    It is well known that hydrogen is the most promising solution of future energy, both for long and medium term strategies. Hydrogen can be produced using many primary sources (natural gas, methane, biomass, etc.), it can be burned or chemically react having a high yield of energy conversion, being a non-polluted fuel. This paper presents the preliminary results obtained by ICSI Rm. Valcea in an experimental-demonstrative conversion energy system made by a sequence of hydrogen purification units and a CO removing reactors until a CO level lower than 10ppm, that finally feeds a hydrogen fuel stack. (author)

  20. Performance testing and economic analysis of a photovoltaic flywheel energy storage and conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Hay, R. D.; Millner, A. R.; Jarvinen, P. O.

    1980-01-01

    A subscale prototype of a flywheel energy storage and conversion system for use with photovoltaic power systems of residential and intermediate load-center size has been designed, built and tested by MIT Lincoln Laboratory. System design, including details of such key components as magnetic bearings, motor generator, and power conditioning electronics, is described. Performance results of prototype testing are given and indicate that this system is the equal of or superior to battery-inverter systems for the same application. Results of cost and user-worth analysis show that residential systems are economically feasible in stand-alone and in some utility-interactive applications.

  1. Conversion of plutonium-containing materials into borosilicate glass using the glass material oxidation and dissolution system

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1996-01-01

    The end of the cold war has resulted in excess plutonium-containing materials (PCMs) in multiple chemical forms. Major problems are associated with the long-term management of these materials: safeguards and nonproliferation issues; health, environment, and safety concerns; waste management requirements; and high storage costs. These issues can be addressed by conversion of the PCMs to glass: however, conventional glass processes require oxide-like feed materials. Conversion of PCMs to oxide-like materials followed by vitrification is a complex and expensive process. A new vitrification process has been invented, the Glass Material Oxidation and Dissolution System (GMODS) to allow direct conversion of PCMs to glass. GMODS directly converts metals, ceramics, and amorphous solids to glass; oxidizes organics with the residue converted to glass; and converts chlorides to borosilicate glass and a secondary sodium chloride stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium (a plutonium surrogate), Zircaloy, stainless steel, multiple oxides, and other materials to glass. Equipment options have been identified for processing rates between 1 and 100,000 t/y. Significant work, including a pilot plant, is required to develop GMODS for applications at an industrial scale

  2. Development of a gas-to-particle conversion model for use in three-dimensional global sulfur budget studies

    International Nuclear Information System (INIS)

    Kreidenweis, S.M.

    1993-08-01

    A fully-parameterized model for the formation and growth of aerosols via gas-to-particle conversion has been developed and tested. A particularly significant contribution is a new method for the prediction of numbers of particles nucleated using information on the vapor source rate, relative humidity, and preexisting aerosol alone, thus eliminating the need to solve a system of coupled ODEs. Preliminary tests indicate substantial reduction in computational costs, but it is recommended that the BIMODAM model be incorporated into a large-scale model of the sulfur cycle in order to more fully test its computational feasibility

  3. Persuasion detection in conversation

    OpenAIRE

    Gilbert, Henry T.

    2010-01-01

    Approved for public release; distribution is unlimited In this thesis, we present a system for annotating persuasion in conversation based on a social-psychological model. We augmented the social model developed by James Cialdini with some of our own categories for annotators to label. The conversations consisted of 37 hostage negotiation transcripts from private and public sources, with all personal information removed from the private source transcripts. We evaluated the level of agre...

  4. The development of two Broadband Vibration Energy Harvesters (BVEH) with adaptive conversion electronics

    Science.gov (United States)

    Clingman, Dan J.; Thiesen, Jack

    2017-04-01

    Historically, piezoelectric vibration energy harvesters have been limited to operation at a single, structurally resonant frequency. A piezoceramic energy harvester, such as a bimorph beam, operating at structural resonance exchanges energy between dynamic and strain regimes. This energy exchange increases the coupling between piezoceramic deformation and electrical charge generation. Two BVEH mechanisms are presented that exploit strain energy management to reduce inertial forces needed to deform the piezoceramic, thus increasing the coupling between structural and electrical energy conversion over a broadband vibration spectrum. Broadband vibration excitation produces a non-sinusoidal electrical wave form from the BVEH device. An adaptive energy conversion circuit was developed that exploits a buck converter to capture the complex waveform energy in a form easily used by standard electrical components.

  5. Development of sustainable CO2 conversion processes for the methanol production

    DEFF Research Database (Denmark)

    Roh, Kosan; Nguyen, Tuan B.H.; Suriyapraphadilok, Uthaiporn

    2015-01-01

    reforming process has to be integrated with the existing conventional methanol plant to obtain a reduced CO2 emission as well as lowered production costs. On the other hand, the CO2 hydrogenation based methanol plant could achieve a reduction of net CO2 emission at a reasonable production cost only......Utilization of CO2 feedstock through CO2 conversion for producing valuable chemicals as an alternative to sequestration of the captured CO2 is attracting increasing attention in recent studies. Indeed, the methanol production process via thermochemical CO2 conversion reactions is considered a prime...... candidate for commercialization. The aim of this study is to examine two different options for a sustainable methanol plant employing the combined reforming and CO2 hydrogenation reactions, respectively. In addition, process improvement strategies for the implementation of the developed processes are also...

  6. Software engineering for the EBR-II data acquisition system conversion

    International Nuclear Information System (INIS)

    Schorzman, W.

    1988-01-01

    The purpose of this paper is to outline how EBR-II engineering approached the data acquisition system (DAS) software conversion project with the restraints of operational transparency and six weeks for final implementation and testing. Software engineering is a relatively new discipline that provides a structured philosopy for software conversion. The software life cycle is structured into six basic steps: 1) initiation, 2) requirements definition, 3) design, 4) programming, 5) testing, and 6) operations. These steps are loosely defined and can be altered to fit specific software applications. DAS software is encompassed from three sources: 1) custom software, 2) system software, and 3) in-house application software. A data flow structure is used to describe the DAS software. The categories are: 1) software used to bring signals into the central processer, 2) software that transforms the analog data to engineering units and then logs the data in the data store, and 3) software used to transport and display the data. The focus of this paper is to describe how the conversion team used a structured engineering approach and utilized the resources available to produce a quality system on time. Although successful, the conversion process provided some pit falls and stumbling blocks. Working through these obstacles enhanced our understanding and surfaced in the form of LESSONS LEARNED, which are gracefully shared in this paper

  7. Plasma heating due to X-B mode conversion in a cylindrical ECR plasma system

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, V.K.; Bora, D. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat (India)

    2004-07-01

    Extra Ordinary (X) mode conversion to Bernstein wave near Upper Hybrid Resonance (UHR) layer plays an important role in plasma heating through cyclotron resonance. Wave generation at UHR and parametric decay at high power has been observed during Electron Cyclotron Resonance (ECR) heating experiments in toroidal magnetic fusion devices. A small linear system with ECR and UHR layer within the system has been used to conduct experiments on X-B conversion and parametric decay process as a function of system parameters. Direct probing in situ is conducted and plasma heating is evidenced by soft x-ray emission measurement. Experiments are performed with hydrogen plasma produced with 160-800 W microwave power at 2.45 GHz of operating frequency at 10{sup -3} mbar pressure. The axial magnetic field required for ECR is such that the resonant surface (B = 875 G) is situated at the geometrical axis of the plasma system. Experimental results will be presented in the paper. (authors)

  8. Speech-To-Text Conversion STT System Using Hidden Markov Model HMM

    Directory of Open Access Journals (Sweden)

    Su Myat Mon

    2015-06-01

    Full Text Available Abstract Speech is an easiest way to communicate with each other. Speech processing is widely used in many applications like security devices household appliances cellular phones ATM machines and computers. The human computer interface has been developed to communicate or interact conveniently for one who is suffering from some kind of disabilities. Speech-to-Text Conversion STT systems have a lot of benefits for the deaf or dumb people and find their applications in our daily lives. In the same way the aim of the system is to convert the input speech signals into the text output for the deaf or dumb students in the educational fields. This paper presents an approach to extract features by using Mel Frequency Cepstral Coefficients MFCC from the speech signals of isolated spoken words. And Hidden Markov Model HMM method is applied to train and test the audio files to get the recognized spoken word. The speech database is created by using MATLAB.Then the original speech signals are preprocessed and these speech samples are extracted to the feature vectors which are used as the observation sequences of the Hidden Markov Model HMM recognizer. The feature vectors are analyzed in the HMM depending on the number of states.

  9. Mobile systems development

    DEFF Research Database (Denmark)

    Pedersen, Ole; Kristiansen, Martin Lund; Kammersgaard, Marc N.

    2007-01-01

    in XP. In general, we find XP well-suited for mobile systems development projects. However, based on our experiences and an analytical comparison we propose the following modifications to XP: Make an essential design to avoid the worst time waste during refactoring. For faster development, reuse code......Development of mobile software is Surrounded by much uncertainty. Immature software platforms on mobile clients, a highly competitive market calling for innovation, efficiency and effectiveness in the development life cycle, and lacking end-user adoption are just some of the realities facing...... development teams in the mobile software industry. By taking a process view on development of mobile systems we seek to explore the strengths and limitations of eXtreme Programming (XP) in the context of mobile software development. Following an experimental approach a mobile systems development project...

  10. Development of high level radwaste treatment and conversion technology. Transmutation technology development

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Suk; Song, T Y; Kim, Y H

    2001-03-01

    The final disposition of spent fuel has been, and continues to be, an important issue of nuclear industry. The conceptual design for the accelerator driven transmutation system HYPER is scheduled to be completed by the year of 2006. As the first step for the conceptual design, a study to determine 1. sub-critical core characteristics, 2. fuel concept, 3. coolant system concept, 4. spallation target concept for the HYPER was performed from 1997 to 2000. Most of concept studies were done on the literature basis. The major objectives of the study is to give a guid-line for the second stage research which will be performed during 2001-2003. In addition, the technologies related with TRU-Zr fuel and Pb-Bi coolant can be utilized for the future nuclear reactor development such as generation 4.

  11. Development of high level radwaste treatment and conversion technology. Transmutation technology development

    International Nuclear Information System (INIS)

    Park, Won Suk; Song, T. Y.; Kim, Y. H.

    2001-03-01

    The final disposition of spent fuel has been, and continues to be, an important issue of nuclear industry. The conceptual design for the accelerator driven transmutation system HYPER is scheduled to be completed by the year of 2006. As the first step for the conceptual design, a study to determine 1. sub-critical core characteristics, 2. fuel concept, 3. coolant system concept, 4. spallation target concept for the HYPER was performed from 1997 to 2000. Most of concept studies were done on the literature basis. The major objectives of the study is to give a guid-line for the second stage research which will be performed during 2001-2003. In addition, the technologies related with TRU-Zr fuel and Pb-Bi coolant can be utilized for the future nuclear reactor development such as generation 4

  12. Doing Systems Development

    DEFF Research Database (Denmark)

    Koch, Christian; Mathiasen, John Bang

    2014-01-01

    Systems development of wind turbine control is competitive with respect to innovation, time and cost. So how can learning possibly occur under such circumstances? Dewey’s pragmatist approach to learning is adopted, emphasising reciprocity between the systems developer’s individual experience...... and the sociotechnical practice. The framework involves the concepts of sociotechnical practice, anchoring of indeterminate situation, and strip of doings towards determinate situation. An ethnographic study was made of four cases of systems development and learning do occur in the cases, enabled by converging anchoring...... of the indeterminate situation and the systems developers different experience. However, an extreme case reveals initiated learning processes and that the interchanges between materiality of the artefacts and systems developers block the learning processes due to a customer with imprecise demands and unclear system...

  13. Low-temperature system for simultaneous counting of conversion electrons and backscattered [gamma]-rays in Moessbauer effect experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ruskov, Todor (Institute for Nuclear Research and Nuclear Energy, Tsarigradsko shosse 72, Sofia 1784 (Bulgaria)); Passage, Guener (Institute for Nuclear Research and Nuclear Energy, Tsarigradsko shosse 72, Sofia 1784 (Bulgaria)); Rastanawi, Abdallah (Institute for Nuclear Research and Nuclear Energy, Tsarigradsko shosse 72, Sofia 1784 (Bulgaria)); Radev, Rumen (Institute for Nuclear Research and Nuclear Energy, Tsarigradsko shosse 72, Sofia 1784 (Bulgaria))

    1994-12-01

    A system for simultaneous detection of conversion electrons, emitted after resonant exciting of [sup 57]Fe, and resonant backscattered [gamma]-rays and X-rays, accompanying the conversion electrons, is described. The system includes a helium proportional counter, for detection of conversion electrons, and a toroidal ''Keisch-type'' proportional counter, connected to the vacuum part of a helium cryostat. ((orig.))

  14. A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

    OpenAIRE

    Naggar H. Saad; Ahmed A. El-Sattar; Mohamed I. Marei

    2016-01-01

    The main challenges of wind energy conversion systems (WECS) are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG) based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG curren...

  15. Flexible Mode Control of Grid Connected Wind Energy Conversion System Using Wavelet

    OpenAIRE

    Jain, Bhavna; Singh, Sameer; Jain, Shailendra; Nema, R. K.

    2015-01-01

    Small wind turbine systems offer services to critical loads during grid faults and also connected back to grid in normal condition. The connection of a wind energy conversion system to the grid requires a robust phase locked loop (PLL) and continuous monitoring of the grid conditions such as overvoltage, undervoltage, overfrequency, underfrequency, and grid outages. This paper describes a flexible control operation to operate a small wind turbine in both stand-alone mode via planned islanding...

  16. Development of High Yield Feedstocks and Biomass Conversion Technology for Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Andrew G. [Univ. of Hawaii, Honolulu, HI (United States); Crow, Susan [Univ. of Hawaii, Honolulu, HI (United States); DeBeryshe, Barbara [Univ. of Hawaii, Honolulu, HI (United States); Ha, Richard [Hamakua Springs County Farms, Hilo, HI (United States); Jakeway, Lee [Hawaiian Commercial and Sugar Company, Puunene, HI (United States); Khanal, Samir [Univ. of Hawaii, Honolulu, HI (United States); Nakahata, Mae [Hawaiian Commercial and Sugar Company, Puunene, HI (United States); Ogoshi, Richard [Univ. of Hawaii, Honolulu, HI (United States); Shimizu, Erik [Univ. of Hawaii, Honolulu, HI (United States); Stern, Ivette [Univ. of Hawaii, Honolulu, HI (United States); Turano, Brian [Univ. of Hawaii, Honolulu, HI (United States); Turn, Scott [Univ. of Hawaii, Honolulu, HI (United States); Yanagida, John [Univ. of Hawaii, Honolulu, HI (United States)

    2015-04-09

    This project had two main goals. The first goal was to evaluate several high yielding tropical perennial grasses as feedstock for biofuel production, and to characterize the feedstock for compatible biofuel production systems. The second goal was to assess the integration of renewable energy systems for Hawaii. The project focused on high-yield grasses (napiergrass, energycane, sweet sorghum, and sugarcane). Field plots were established to evaluate the effects of elevation (30, 300 and 900 meters above sea level) and irrigation (50%, 75% and 100% of sugarcane plantation practice) on energy crop yields and input. The test plots were extensive monitored including: hydrologic studies to measure crop water use and losses through seepage and evapotranspiration; changes in soil carbon stock; greenhouse gas flux (CO2, CH4, and N2O) from the soil surface; and root morphology, biomass, and turnover. Results showed significant effects of environment on crop yields. In general, crop yields decrease as the elevation increased, being more pronounced for sweet sorghum and energycane than napiergrass. Also energy crop yields were higher with increased irrigation levels, being most pronounced with energycane and less so with sweet sorghum. Daylight length greatly affected sweet sorghum growth and yields. One of the energy crops (napiergrass) was harvested at different ages (2, 4, 6, and 8 months) to assess the changes in feedstock characteristics with age and potential to generate co-products. Although there was greater potential for co-products from younger feedstock, the increased production was not sufficient to offset the additional cost of harvesting multiple times per year. The feedstocks were also characterized to assess their compatibility with biochemical and thermochemical conversion processes. The project objectives are being continued through additional support from the Office of Naval Research, and the Biomass Research and Development

  17. Conversation Analysis.

    Science.gov (United States)

    Schiffrin, Deborah

    1990-01-01

    Summarizes the current state of research in conversation analysis, referring primarily to six different perspectives that have developed from the philosophy, sociology, anthropology, and linguistics disciplines. These include pragmatics; speech act theory; interactional sociolinguistics; ethnomethodology; ethnography of communication; and…

  18. Development of conversion efficient processes for +525[degree]C pitch to low boiling distillates

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, R.N.

    1992-10-22

    Catalytic hydroprocessing of Esso pitch (+525[degree]C fraction) was investigated using a continuous reactor system at various operating conditions. The catalysts studied included ZnCl[sub 2], SnCl[sub 4], SiO[sub 2], Ni/W, Co/Mo, Zn/Cr, and H[sub 3]PO[sub 4]/SiO[sub 2]. The catalysts were characterized by surface area and acidity measurements. The gas and liquid products were collected and analyzed, and results are presented. The work demonstrates the effectiveness of a continuous flash hydropyrolysis process for the conversion of petroleum residuals to low boiling distillates. It has been found that in the presence of ZnCl[sub 2] catalyst, conversions up to 92% can be obtained under relatively moderate conditions of temperature and hydrogen pressure. The formation of gaseous products is less than 5 wt %. The favorable conditions of operation, a reduction in sulfur content, increase in H/C ratio, and a significant yield of low boiling distillates is obtained. The process variables, such as temperature, hydrogen pressure, and liquid residence times influence product yield and quality. Coke formation was almost negligible even under conditions of high pitch conversion. A review of various techniques of pyrolysis and hydropyrolysis of materials such as coal, bitumen, and heavy oil is included. 198 refs., 46 figs., 40 tabs.

  19. Complex thermal energy conversion systems for efficient use of locally available biomass

    International Nuclear Information System (INIS)

    Kalina, Jacek

    2016-01-01

    This paper is focused on a theoretical study in search for new technological solutions in the field of electricity generation from biomass in small-scale distributed cogeneration systems. The purpose of this work is to draw readers' attention to possibilities of design complex multi-component hybrid and combined technological structures of energy conversion plants for effective use of locally available biomass resources. As an example, there is presented analysis of cogeneration system that consists of micro-turbine, high temperature fuel cell, inverted Bryton cycle module and biomass gasification island. The project assumes supporting use of natural gas and cooperation of the plant with a low-temperature district heating network. Thermodynamic parameters, energy conversion effectiveness and economic performance are examined. Results show relatively high energy conversion performance and on the other hand weak financial indices of investment projects at the current level of energy prices. It is however possible under certain conditions to define an optimistic business model that leads to a feasible project. - Highlights: • Concept of biomass energy conversion plant is proposed and theoretically analysed. • MCFC type fuel cell is fuelled with biomass gasification gas. • Natural gas fired microturbine is considered as a source of continuous power. • Inverted Bryton Cycle is considered for utilisation of high temperature exhaust gas.

  20. Recent developments in the production of liquid fuels via catalytic conversion of microalgae: experiments and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Fan; Wang, Pin; Duan, Yuhua; Link, Dirk; Morreale, Bryan

    2012-01-01

    Due to continuing high demand, depletion of non-renewable resources and increasing concerns about climate change, the use of fossil fuel-derived transportation fuels faces relentless challenges both from a world markets and an environmental perspective. The production of renewable transportation fuel from microalgae continues to attract much attention because of its potential for fast growth rates, high oil content, ability to grow in unconventional scenarios, and inherent carbon neutrality. Moreover, the use of microalgae would minimize ‘‘food versus fuel’’ concerns associated with several biomass strategies, as microalgae do not compete with food crops in the food chain. This paper reviews the progress of recent research on the production of transportation fuels via homogeneous and heterogeneous catalytic conversions of microalgae. This review also describes the development of tools that may allow for a more fundamental understanding of catalyst selection and conversion processes using computational modelling. The catalytic conversion reaction pathways that have been investigated are fully discussed based on both experimental and theoretical approaches. Finally, this work makes several projections for the potential of various thermocatalytic pathways to produce alternative transportation fuels from algae, and identifies key areas where the authors feel that computational modelling should be directed to elucidate key information to optimize the process.

  1. Converse Barrier Certificate Theorem

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2013-01-01

    This paper presents a converse barrier certificate theorem for a generic dynamical system.We show that a barrier certificate exists for any safe dynamical system defined on a compact manifold. Other authors have developed a related result, by assuming that the dynamical system has no singular...... points in the considered subset of the state space. In this paper, we redefine the standard notion of safety to comply with generic dynamical systems with multiple singularities. Afterwards, we prove the converse barrier certificate theorem and illustrate the differences between ours and previous work...

  2. EXAMINING A SERIES RESONANT INVERTER CIRCUIT TO USE IN THE PHOTOVOLTAIC ENERGY CONVERSION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Engin ÇETİN

    2004-03-01

    Full Text Available As we know, solar energy is the energy source which is environment friendly, renewable, and can be found easily. Particularly, in the recent years, interest on producing electrical energy by alternative energy sources increased because of the fact that underground sources are not enough to produce energy in the future and also these sources cause enviromental pollution. The solar energy is one of the most popular one among the alternative energy sources. Photovoltaic systems produce the electrical energy from the sunlight. In this study, a series resonant inverter circuit which is used in the photovoltaic energy conversion systems has been examined.Effects of the series resonant inverter circuit on the photovoltaic energy conversion system have been investigated and examined

  3. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced energy conversion systems. Part 1: Open-cycle gas turbines

    Science.gov (United States)

    Brown, D. H.; Corman, J. C.

    1976-01-01

    Ten energy conversion systems are defined and analyzed in terms of efficiency. These include: open-cycle gas turbine recuperative; open-cycle gas turbine; closed-cycle gas turbine; supercritical CO2 cycle; advanced steam cycle; liquid metal topping cycle; open-cycle MHD; closed-cycle inert gas MHD; closed-cycle liquid metal MHD; and fuel cells. Results are presented.

  4. Supercritical carbon dioxide Brayton power conversion cycle for battery optimized reactor integral system

    International Nuclear Information System (INIS)

    Kim, T. W.; Kim, N. H.; Suh, K. Y.

    2007-01-01

    Supercritical carbon dioxide (SCO 2 ) promises a high power conversion efficiency of the recompression Brayton cycle due to its excellent compressibility reducing the compression work at the bottom of the cycle and to a higher density than helium or steam decreasing the component size. The SCO 2 Brayton cycle efficiency as high as 45% furnishes small sized nuclear reactors with economical benefits on the plant construction and maintenance. A 23 MWth lead-cooled Battery Optimized Reactor Integral System (BORIS) is being developed as an ultra-long-life, versatile-purpose, fast-spectrum reactor. BORIS is coupled to the SCO 2 Brayton cycle needing less room relative to the Rankine steam cycle because of its smaller components. The SCO 2 Brayton cycle of BORIS consists of a 16 MW turbine, a 32 MW high temperature recuperator, a 14 MW low temperature recuperator, an 11 MW precooler and 2 and 2.8 MW compressors. Entering six heat exchangers between primary and secondary system at 19.9 MPa and 663 K, the SCO 2 leaves the heat exchangers at 19.9 MPa and 823 K. The promising secondary system efficiency of 45% was calculated by a theoretical method in which the main parameters include pressure, temperature, heater power, the turbine's, recuperators' and compressors' efficiencies, and the flow split ratio of SCO 2 going out from the low temperature recuperator. Development of Modular Optimized Brayton Integral System (MOBIS) is being devised as the SCO 2 Brayton cycle energy conversion cycle for BORIS. MOBIS consists of Loop Operating Brayton Optimization Study (LOBOS) for experimental Brayton cycle loop and Gas Advanced Turbine Operation Study (GATOS) for the SCO 2 turbine. Liquid-metal Energy Exchanger Integral System (LEXIS) serves to couple BORIS and MOBIS. LEXIS comprises Physical Aspect Thermal Operation System (PATOS) for SCO 2 thermal hydraulic characteristics, Shell-and-tube Overall Layout Optimization Study (SOLOS) for shell-and-tube heat exchanger, Printed

  5. Clinical evaluation of digital angiographic system equipped with the Safire' flat-panel detector of a direct conversion type

    International Nuclear Information System (INIS)

    Miura, Yoshiaki; Miura, Yusuke; Goto, Keiichi

    2003-01-01

    This report presents a report on clinical evaluation of our newly developed flat-panel X-ray detector of a direct conversion type, designed to provide images of a resolution higher than, or at least equal to, that ensured by X-ray photographic films, in clinical digital X-ray cinematography. This new detector was named 'Safire' the acronym of 'Shimadzu advanced flat imaging receptor', emphasizing its high technological level, such as the capability to ensure high quality of images. The clinical evaluation of Shimadzu DIGITEX Premier digital angiography system, equipped with this new flat-panel X-ray detector of a direct conversion type, has been started in March, 2003, at the Kokura Memorial Hospital in Kyushu, Japan. (author)

  6. Industrialized Information Systems Development

    DEFF Research Database (Denmark)

    Havn, Erling; Bansler, Jørgen P.

    1996-01-01

    The production of application software is rapidly being industrialized. Computer manufacturers and software houses produce a rapidly growing number of generic software applications and systems, and more and more user companies choose to build their computer-based information systems...... with such generic products, instead of custom made software. We discuss how the move away from traditional in-house development and the increasing use of generic software is likely to transform IS development in the near future. We conclude that these developments will make new demands on the information systems...

  7. Electric utility application of wind energy conversion systems on the island of Oahu

    Energy Technology Data Exchange (ETDEWEB)

    Lindley, C.A.; Melton, W.C.

    1979-02-23

    This wind energy application study was performed by The Aerospace Corporation for the Wind Systems Branch of the Department of Energy. The objective was to identify integration problems for a Wind Energy Conversion System (WECS) placed into an existing conventional utility system. The integration problems included environmental, institutional and technical aspects as well as economic matters, but the emphasis was on the economics of wind energy. The Hawaiian Electric Company utility system on the island of Oahu was selected for the study because of the very real potential for wind energy on that island, and because of the simplicity afforded in analyzing that isolated utility.

  8. System Requirements Document for the Molten Salt Reactor Experiment 233U conversion system

    International Nuclear Information System (INIS)

    Aigner, R.D.

    2000-01-01

    The purpose of the conversion process is to convert the 233 U fluoride compounds that are being extracted from the Molten Salt Reactor Experiment (MSRE) equipment to a stable oxide for long-term storage at Bldg. 3019

  9. Uranium Metal to Oxide Conversion by Air Oxidation –Process Development

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A

    2001-12-31

    Published technical information for the process of metal-to-oxide conversion of uranium components has been reviewed and summarized for the purpose of supporting critical decisions for new processes and facilities for the Y-12 National Security Complex. The science of uranium oxidation under low, intermediate, and high temperature conditions is reviewed. A process and system concept is outlined and process parameters identified for uranium oxide production rates. Recommendations for additional investigations to support a conceptual design of a new facility are outlined.

  10. [Changes of soil physical properties during the conversion of cropland to agroforestry system].

    Science.gov (United States)

    Wang, Lai; Gao, Peng Xiang; Liu, Bin; Zhong, Chong Gao; Hou, Lin; Zhang, Shuo Xin

    2017-01-01

    To provide theoretical basis for modeling and managing agroforestry systems, the influence of conversion of cropland to agroforestry system on soil physical properties was investigated via a walnut (Juglans regia)-wheat (Triticum aestivum) intercropping system, a wide spreading local agroforestry model in northern Weihe River of loess area, with the walnut and wheat monoculture systems as the control. The results showed that the improvement of the intercropping system on soil physical properties mainly appeared in the 0-40 cm soil layer. The intercropping system could prevent soil bulk density rising in the surface soil (0-20 cm), and the plow pan in the 20-40 cm soil layer could be significantly alleviated. The intercropping system had conti-nuous improvement on soil field capacity in each soil layer with the planting age increase, and the soil field capacity was higher than that of each monoculture system in each soil layer (except 20-40 cm soil layer) since the 5th year after planting. The intercropping system had continuous improvement on soil porosity in each soil layer, but mainly in the 0-20 and 20-40 cm soil layer, and the ratio of capillary porosity was also improved. The soil bulk density, field capacity and soil porosity obtained continuous improvement during the conversion of cropland to agroforestry system, and the improvement on soil physical properties was stronger in shallow soil layer than in deep soil.

  11. Applied research on energy storage and conversion for photovoltaic and wind energy systems. Volume II. Photovoltaic systems with energy storage. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This volume of the General Electric study was directed at an evaluation of those energy storage technologies deemed best suited for use in conjunction with a photovoltaic energy conversion system in utility, residential and intermediate applications. Break-even cost goals are developed for several storage technologies in each application. These break-even costs are then compared with cost projections presented in Volume I of this report to show technologies and time frames of potential economic viability. The form of the presentation allows the reader to use more accurate storage system cost data as they become available. The report summarizes the investigations performed and presents the results, conclusions and recommendations pertaining to use of energy storage with photovoltaic energy conversion systems. Candidate storage concepts studied include (1) above ground and underground pumped hydro, (2) underground compressed air, (3) electric batteries, (4) flywheels, and (5) hydrogen production and storage. (WHK)

  12. Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients

    OpenAIRE

    Morais, William G.; Lima, Gilberto; Gomes, Wellington J. A. S.; Huguenin, Fritz

    2018-01-01

    Ever-rising energy demand, fossil fuel dependence, and climate issues have harmful consequences to the society. Exploring clean and renewable energy to diversify the world energy matrix has become an urgent matter. Less explored or unexplored renewable energy sources like the salinity and proton gradient energy are an attractive alternative with great energy potential. This paper discusses important electrochemical systems for energy conversion from natural and artificial concentration gradie...

  13. Legal-institutional arrangements facilitating offshore wind energy conversion systems (WECS) utilization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, L.H.

    1977-09-01

    Concern for the continuing sufficiency of energy supplies in the U.S. has tended to direct increasing attention to unconventional sources of supply, including wind energy. Some of the more striking proposals for the utilization of wind energy relate to offshore configurations. The legal-institutional arrangements for facilitating the utilization of offshore wind energy conversion systems (WECS) are examined by positioning three program alternatives and analyzing the institutional support required for the implementation of each.

  14. Developing a mesophilic co-culture for direct conversion of cellulose to butanol in consolidated bioprocess.

    Science.gov (United States)

    Wang, Zhenyu; Cao, Guangli; Zheng, Ju; Fu, Defeng; Song, Jinzhu; Zhang, Junzheng; Zhao, Lei; Yang, Qian

    2015-01-01

    Consolidated bioprocessing (CBP) of butanol production from cellulosic biomass is a promising strategy for cost saving compared to other processes featuring dedicated cellulase production. CBP requires microbial strains capable of hydrolyzing biomass with enzymes produced on its own with high rate and high conversion and simultaneously produce a desired product at high yield. However, current reported butanol-producing candidates are unable to utilize cellulose as a sole carbon source and energy source. Consequently, developing a co-culture system using different microorganisms by taking advantage of their specific metabolic capacities to produce butanol directly from cellulose in consolidated bioprocess is of great interest. This study was mainly undertaken to find complementary organisms to the butanol producer that allow simultaneous saccharification and fermentation of cellulose to butanol in their co-culture under mesophilic condition. Accordingly, a highly efficient and stable consortium N3 on cellulose degradation was first developed by multiple subcultures. Subsequently, the functional microorganisms with 16S rRNA sequences identical to the denaturing gradient gel electrophoresis (DGGE) profile were isolated from consortium N3. The isolate Clostridium celevecrescens N3-2 exhibited higher cellulose-degrading capability was thus chosen as the partner strain for butanol production with Clostridium acetobutylicum ATCC824. Meanwhile, the established stable consortium N3 was also investigated to produce butanol by co-culturing with C. acetobutylicum ATCC824. Butanol was produced from cellulose when C. acetobutylicum ATCC824 was co-cultured with either consortium N3 or C. celevecrescens N3-2. Co-culturing C. acetobutylicum ATCC824 with the stable consortium N3 resulted in a relatively higher butanol concentration, 3.73 g/L, and higher production yield, 0.145 g/g of glucose equivalent. The newly isolated microbial consortium N3 and strain C. celevecrescens N3

  15. Final Report on Development of Thermoanaerobacterium saccharolyticum for the conversion of lignocellulose to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Herring, Christopher D.; Kenealy, William R.; Shaw, A. Joe; Raman, Babu; Tschaplinski, Timothy J.; Brown, Steven D.; Davison, Brian H.; Covalla, Sean F.; Sillers, W. Ryan; Xu, Haowen; Tsakraklides, Vasiliki; Hogsett, David A.

    2012-01-24

    This project addressed the need for economical technology for the conversion of lignocellulosic biomass to fuels, specifically the conversion of pretreated hardwood to ethanol. The technology developed is a set of strains of the bacterium Thermoanaerobacterium saccharolyticum and an associated fermentation process for pretreated hardwood. Tools for genetic engineering and analysis of the organism were developed, including a markerless mutation method, a complete genome sequence and a set of gene expression profiles that show the activity of its genes under a variety of conditions relevant to lignocellulose conversion. Improved strains were generated by selection and genetic engineering to be able to produce higher amounts of ethanol (up to 70 g/L) and to be able to better tolerate inhibitory compounds from pretreated hardwood. Analysis of these strains has generated useful insight into the genetic basis for desired properties of biofuel producing organisms. Fermentation conditions were tested and optimized to achieve ethanol production targets established in the original project proposal. The approach proposed was to add cellulase enzymes to the fermentation, a method called Simultaneous Saccharification and Fermentation (SSF). We had reason to think SSF would be an efficient approach because the optimal temperature and pH for the enzymes and bacterium are very close. Unfortunately, we discovered that commercially available cellulases are inactivated in thermophilic SSF by a combination of low redox potential and ethanol. Despite this, progress was made against the fermentation targets using bacterial cellulases. Thermoanaerobacterium saccharolyticum may still prove to be a commercially viable technology should cellulase enzyme issues be addressed. Moreover, the organism was demonstrated to produce ethanol at approximately theoretical yield from oligomeric hemicellulose extracts, an ability that may prove to be uniquely valuable in pretreatment configurations in

  16. Conversion of Hanford site well locations to Washington coordinate system of 1983, South Zone 1991 (WCS83S)

    International Nuclear Information System (INIS)

    Burnett, R.A.; Tzemos, S.; Dietz, L.A.

    1993-12-01

    Past construction and survey practices have resulted in the use of multiple local coordinate systems for measuring and reporting the horizontal position of wells and other facilities and locations on the Hanford Site. This report describes the development of a coordinate transformation process and algorithm and its application to the conversion of the horizontal coordinates of Hanford site wells from the various local coordinate systems and datums to a single standard coordinate system, the Washington Coordinate system of 1983, South Zone 1991 (WCS83S). The coordinate transformation algorithm, implemented as a computer program called CTRANS, uses standard two-dimensional translation, rotation, and scaling transformation equations and can be applied to any set of horizontal point locations. For each point to be transformed, the coefficients of the transformation equations are calculated locally, using the coordinates of the three nearest registration points (points with known locations in both coordinate systems). The report contains a discussion of efforts to verify and validate both the software and the well location data, a description of the methods used to estimate transformation and registration point accuracy, instructions for using the computer program, and a summary of the Hanford well conversion results for each local coordinate system and datum. Also included are the results of using recent U.S. Army Corps of Engineers survey data to obtain estimated measures of location errors in wells for which the local coordinate data source is undocumented, unverified, and therefore of unknown accuracy

  17. Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    Southern Company Services

    2009-01-31

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, has routinely demonstrated gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This final report summarizes the results of the technology development work conducted at the PSDF through January 31, 2009. Twenty-one major gasification test campaigns were completed, for a total of more than 11,000 hours of gasification operation. This operational experience has led to significant advancements in gasification technologies.

  18. Integration of deep geothermal energy and woody biomass conversion pathways in urban systems

    International Nuclear Information System (INIS)

    Moret, Stefano; Peduzzi, Emanuela; Gerber, Léda; Maréchal, François

    2016-01-01

    Highlights: • Novel optimization-based methodology to integrate renewable energy systems in cities. • Multiperiod model including storage, heat integration and Life Cycle Assessment. • Case study: systematic assessment of deep geothermal and wood conversion pathways. • Identification of novel wood-geothermal hybrid systems leading to higher efficiencies. • Extensive Supplementary Material to ensure full reproducibility of the work. - Abstract: Urban systems account for about two-thirds of global primary energy consumption and energy-related greenhouse gas emissions, with a projected increasing trend. Deep geothermal energy and woody biomass can be used for the production of heat, electricity and biofuels, thus constituting a renewable alternative to fossil fuels for all end-uses in cities: heating, cooling, electricity and mobility. This paper presents a methodology to assess the potential for integrating deep geothermal energy and woody biomass in an urban energy system. The city is modeled in its entirety as a multiperiod optimization problem with the total annual cost as an objective, assessing as well the environmental impact with a Life Cycle Assessment approach. For geothermal energy, deep aquifers and Enhanced Geothermal Systems are considered for stand-alone production of heat and electricity, and for cogeneration. For biomass, besides direct combustion and cogeneration, conversion to biofuels by a set of alternative processes (pyrolysis, Fischer-Tropsch synthesis and synthetic natural gas production) is studied. With a scenario-based approach, all pathways are first individually evaluated. Secondly, all possible combinations between geothermal and biomass options are systematically compared, taking into account the possibility of hybrid systems. Results show that integrating these two resources generates configurations featuring both lower costs and environmental impacts. In particular, synergies are found in innovative hybrid systems using

  19. Development of Electro-Microbial Carbon Capture and Conversion Systems

    KAUST Repository

    Al Rowaihi, Israa

    2017-01-01

    to fix ca. 800 Gt (gigaton) of CO2 in the planets largest carbon-capture process. Photosynthesis combines light harvesting, charge separation, catalytic water splitting, generation of reduction equivalents (NADH), energy (ATP) production and CO2 fixation

  20. Development of a mini-orange spectrometer for conversion electron study

    International Nuclear Information System (INIS)

    Mishra, N.R.; Chakravarty, V.; Chintalapudi, S.N.; Ghugre, S.S.; Sastry, D.L.

    1996-01-01

    Conversion electrons provide with an unique tool to have an unambiguous multipolarity assignment for the observed gamma transitions. The fabrication of an electron spectrometer to detect these conversion electrons is a non-trivial task

  1. Solid Waste Information and Tracking System Server Conversion Project Management Plan

    International Nuclear Information System (INIS)

    GLASSCOCK, J.A.

    2000-01-01

    The Project Management Plan governing the conversion of SWITS to a client-server architecture. The PMP describes the background, planning and management of the SWITS conversion. Requirements and specification documentation needed for the SWITS conversion

  2. Carbon conversion efficiency and central metabolic fluxes in developing sunflower (Helianthus annuus L.) embryos.

    Science.gov (United States)

    Alonso, Ana P; Goffman, Fernando D; Ohlrogge, John B; Shachar-Hill, Yair

    2007-10-01

    The efficiency with which developing sunflower embryos convert substrates into seed storage reserves was determined by labeling embryos with [U-(14)C6]glucose or [U-(14)C5]glutamine and measuring their conversion to CO2, oil, protein and other biomass compounds. The average carbon conversion efficiency was 50%, which contrasts with a value of over 80% previously observed in Brassica napus embryos (Goffman et al., 2005), in which light and the RuBisCO bypass pathway allow more efficient conversion of hexose to oil. Labeling levels after incubating sunflower embryos with [U-(14)C4]malate indicated that some carbon from malate enters the plastidic compartment and contributes to oil synthesis. To test this and to map the underlying pattern of metabolic fluxes, separate experiments were carried out in which embryos were labeled to isotopic steady state using [1-(13)C1]glucose, [2-(13)C1]glucose, or [U-(13)C5]glutamine. The resultant labeling in sugars, starch, fatty acids and amino acids was analyzed by NMR and GC-MS. The fluxes through intermediary metabolism were then quantified by computer-aided modeling. The resulting flux map accounted well for the labeling data, was in good agreement with the observed carbon efficiency, and was further validated by testing for agreement with gas exchange measurements. The map shows that the influx of malate into oil is low and that flux through futile cycles (wasting ATP) is low, which contrasts with the high rates previously determined for growing root tips and heterotrophic cell cultures.

  3. Real time implementation and control validation of the wind energy conversion system

    Science.gov (United States)

    Sattar, Adnan

    The purpose of the thesis is to analyze dynamic and transient characteristics of wind energy conversion systems including the stability issues in real time environment using the Real Time Digital Simulator (RTDS). There are different power system simulation tools available in the market. Real time digital simulator (RTDS) is one of the powerful tools among those. RTDS simulator has a Graphical User Interface called RSCAD which contains detail component model library for both power system and control relevant analysis. The hardware is based upon the digital signal processors mounted in the racks. RTDS simulator has the advantage of interfacing the real world signals from the external devices, hence used to test the protection and control system equipments. Dynamic and transient characteristics of the fixed and variable speed wind turbine generating systems (WTGSs) are analyzed, in this thesis. Static Synchronous Compensator (STATCOM) as a flexible ac transmission system (FACTS) device is used to enhance the fault ride through (FRT) capability of the fixed speed wind farm. Two level voltage source converter based STATCOM is modeled in both VSC small time-step and VSC large time-step of RTDS. The simulation results of the RTDS model system are compared with the off-line EMTP software i.e. PSCAD/EMTDC. A new operational scheme for a MW class grid-connected variable speed wind turbine driven permanent magnet synchronous generator (VSWT-PMSG) is developed. VSWT-PMSG uses fully controlled frequency converters for the grid interfacing and thus have the ability to control the real and reactive powers simultaneously. Frequency converters are modeled in the VSC small time-step of the RTDS and three phase realistic grid is adopted with RSCAD simulation through the use of optical analogue digital converter (OADC) card of the RTDS. Steady state and LVRT characteristics are carried out to validate the proposed operational scheme. Simulation results show good agreement with real

  4. Making sense of the emerging conversation in evaluation about systems thinking and complexity science.

    Science.gov (United States)

    Gates, Emily F

    2016-12-01

    In the last twenty years, a conversation has emerged in the evaluation field about the potential of systems thinking and complexity science (STCS) to transform the practice of evaluating social interventions. Documenting and interpreting this conversation are necessary to advance our understanding of the significance of using STCS in planning, implementing, and evaluating social interventions. Guided by a generic framework for evaluation practice, this paper reports on an inter-disciplinary literature review and argues that STCS raises some new ways of thinking about and carrying out the following six activities: 1) supporting social problem solving; 2) framing interventions and contexts; 3) selecting and using methods; 4) engaging in valuing; 5) producing and justifying knowledge; and 6) facilitating use. Following a discussion of these issues, future directions for research and practice are suggested. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Nuclear material control and accounting system evaluation in uranium conversion operations

    International Nuclear Information System (INIS)

    Moreira, Jose Pontes

    1994-01-01

    The Nuclear Material Control and Accounting Systems in uranium conversion operations are described. The conversion plant, uses ammonium diuranate (ADU), as starting material for the production of uranium hexafluoride. A combination of accountability and verification measurement is used to verify physical inventory quantities. Two types of inspection are used to minimize the measurements uncertainty of the Material Unaccounted For (MUF) : Attribute inspection and Variation inspection. The mass balance equation is the base of an evaluation of a Material Balance Area (MBA). Statistical inference is employed to facilitate rapid inventory taking and enhance material control of Safeguards. The calculation of one sampling plan for a MBA and the methodology of inspection evaluation are also described. We have two kinds of errors : no detection and false delation. (author)

  6. Development of low-cost silicon crystal growth techniques for terrestrial photovoltaic solar energy conversion

    Science.gov (United States)

    Zoutendyk, J. A.

    1976-01-01

    Because of the growing need for new sources of electrical energy, photovoltaic solar energy conversion is being developed. Photovoltaic devices are now being produced mainly from silicon wafers obtained from the slicing and polishing of cylindrically shaped single crystal ingots. Inherently high-cost processes now being used must either be eliminated or modified to provide low-cost crystalline silicon. Basic to this pursuit is the development of new or modified methods of crystal growth and, if necessary, crystal cutting. If silicon could be grown in a form requiring no cutting, a significant cost saving would potentially be realized. Therefore, several techniques for growth in the form of ribbons or sheets are being explored. In addition, novel techniques for low-cost ingot growth and cutting are under investigation.

  7. A World at Risk: Aggregating Development Trends to Forecast Global Habitat Conversion.

    Science.gov (United States)

    Oakleaf, James R; Kennedy, Christina M; Baruch-Mordo, Sharon; West, Paul C; Gerber, James S; Jarvis, Larissa; Kiesecker, Joseph

    2015-01-01

    A growing and more affluent human population is expected to increase the demand for resources and to accelerate habitat modification, but by how much and where remains unknown. Here we project and aggregate global spatial patterns of expected urban and agricultural expansion, conventional and unconventional oil and gas, coal, solar, wind, biofuels and mining development. Cumulatively, these threats place at risk 20% of the remaining global natural lands (19.68 million km2) and could result in half of the world's biomes becoming >50% converted while doubling and tripling the extent of land converted in South America and Africa, respectively. Regionally, substantial shifts in land conversion could occur in Southern and Western South America, Central and Eastern Africa, and the Central Rocky Mountains of North America. With only 5% of the Earth's at-risk natural lands under strict legal protection, estimating and proactively mitigating multi-sector development risk is critical for curtailing the further substantial loss of nature.

  8. Selected legal and institutional issues related to Ocean Thermal Energy Conversion (OTEC) development

    Energy Technology Data Exchange (ETDEWEB)

    Nanda, V. P.

    1979-06-01

    Ocean Thermal Energy Conversion (OTEC), an attractive alternative to traditional energy sources, is still in the early stages of development. To facilitate OTEC commercialization, it is essential that a legal and institutional framework be designed now so as to resolve uncertainties related to OTEC development, primarily involving jurisdictional, regulatory, and environmental issues. The jurisdictional issues raised by OTEC use are dependent upon the site of an OTEC facility and its configuration; i.e., whether the plant is a semipermanent fixture located offshore or a migrating plant ship that provides a source of energy for industry at sea. These issues primarily involve the division of authority between the Federal Government and the individual coastal states. The regulatory issues raised are largely speculative: they involve the adaptation of existing mechanisms to OTEC operation. Finally, the environmental issues raised center around compliance with the National Environmental Policy Act (NEPA) as well as international agreements. 288 references.

  9. Development of Production Systems

    DEFF Research Database (Denmark)

    Christiansen, Thomas Bøhm

    1997-01-01

    This paper presents the initial considerations related to a Ph.D. study initiated at IPV, DTU in February 1997, concerning the research subject "Development of Production Systems". The content and aim of this paper is to 1) to introduce the study by......This paper presents the initial considerations related to a Ph.D. study initiated at IPV, DTU in February 1997, concerning the research subject "Development of Production Systems". The content and aim of this paper is to 1) to introduce the study by...

  10. Adequacy assessment of composite generation and transmission systems incorporating wind energy conversion systems

    Science.gov (United States)

    Gao, Yi

    The development and utilization of wind energy for satisfying electrical demand has received considerable attention in recent years due to its tremendous environmental, social and economic benefits, together with public support and government incentives. Electric power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of wind energy facilities therefore affect power system reliability in a different manner than those of conventional systems. The reliability impact of such a highly variable energy source is an important aspect that must be assessed when the wind power penetration is significant. The focus of the research described in this thesis is on the utilization of state sampling Monte Carlo simulation in wind integrated bulk electric system reliability analysis and the application of these concepts in system planning and decision making. Load forecast uncertainty is an important factor in long range planning and system development. This thesis describes two approximate approaches developed to reduce the number of steps in a load duration curve which includes load forecast uncertainty, and to provide reasonably accurate generating and bulk system reliability index predictions. The developed approaches are illustrated by application to two composite test systems. A method of generating correlated random numbers with uniform distributions and a specified correlation coefficient in the state sampling method is proposed and used to conduct adequacy assessment in generating systems and in bulk electric systems containing correlated wind farms in this thesis. The studies described show that it is possible to use the state sampling Monte Carlo simulation technique to quantitatively assess the reliability implications associated with adding wind power to a composite generation and transmission system including the effects of multiple correlated wind sites. This is an important

  11. A comparative study between three sensorless control strategies for PMSG in wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Brahmi, Jemaa; Krichen, Lotfi; Ouali, Abderrazak [Advanced Control and Energy Management Research Unit ENIS, Department of Electrical Engineering, University of Sfax, 3038 Sfax (Tunisia)

    2009-09-15

    This paper presents a comparative study of sliding mode, artificial neural network and model reference adaptive speed observers for a speed sensorless permanent magnet synchronous generator (PMSG) in wind energy conversion system (WECS). Wind velocity and position sensorless operating methods for wind generation system using observer are proposed only by measuring phase voltages and currents. Maximum wind energy extraction is achieved by running the wind turbine generator in variable-speed mode. In addition the three speed observers are compared to verify the robustness against parameter variations. (author)

  12. Power converter topologies for wind energy conversion systems: Integrated modeling, control strategy and performance simulation

    Energy Technology Data Exchange (ETDEWEB)

    Melicio, R.; Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal)

    2010-10-15

    This paper presents new integrated model for variable-speed wind energy conversion systems, considering a more accurate dynamic of the wind turbine, rotor, generator, power converter and filter. Pulse width modulation by space vector modulation associated with sliding mode is used for controlling the power converters. Also, power factor control is introduced at the output of the power converters. Comprehensive performance simulation studies are carried out with matrix, two-level and multilevel power converter topologies in order to adequately assert the system performance. Conclusions are duly drawn. (author)

  13. New Multiphase Hybrid Boost Converter with Wide Conversion Ratio for PV System

    Directory of Open Access Journals (Sweden)

    Ioana-Monica Pop-Calimanu

    2014-01-01

    Full Text Available A new multiphase hybrid boost converter, with wide conversion ratio as a solution for photovoltaic energy system, is presented in this paper. To ensure that all the phases of the converter operate at the same switching frequency we use interleaving topology. The proposed converter can be used as an interface between the PV system and the DC load/inverter. This multiphase converter has the advantage of reduced value and physical size of the input and output capacitor as well as the effort for the inductors. To validate the operation of the converter we provide the analyses and the simulation results of the converter.

  14. Productivity of coffee crop (Coffea arabica L.) in conversion to the organic production system

    OpenAIRE

    Malta, Marcelo Ribeiro; Empresa de Pesquisa Agropecuária de Minas Gerais - EPAMIG; Pereira, Rosemary Gualberto Fonseca Alvarenga; Universidade Federal de Lavras - UFLA; Chagas, Sílvio Júlio de Rezende; Empresa de Pesquisa Agropecuária de Minas Gerais - EPAMIG; Guimarães, Rubens José; Universidade Federal de Lavras - UFLA

    2008-01-01

    This experiment was carried out in Lavras, MG, to verify the productivity of coffee crop (Coffea arabica L.) in conversion to the organic production system. The experiment was set in a six-year old coffee crop of the cultivar Catuaí Amarelo IAC 86, with spacing of 4,0 x 0,6 m, previously cultivated under the conventional system. In the organic treatments a 4 x 4 balanced lattice design with 5 replications in a 3 x 2 x 2 factorial scheme was used, besides 4 additional treatments. The f...

  15. The photochemical conversion of solar energy into electrical energy: Eosin-Arabinose system

    Energy Technology Data Exchange (ETDEWEB)

    Gangotri, K.M. [Department of Chemistry, Solar Energy Laboratory, Jai Narain Vyas University, Jodhpur 342 033, Rajasthan (India); Bhimwal, Mukesh Kumar [Solar Energy Laboratory, Jai Narain Vyas University, Jodhpur 342 033, Rajasthan (India)

    2010-12-15

    A photosensitizer -Eosin and a reductant- Arabinose have been used in the photogalvanic cell for photochemical conversion of solar energy into electrical energy. The generated photopotential and photocurrent are 679.0 mV and 240.0 {mu}A respectively. The maximum power of the cell is 162.96 {mu}W whereas the observed power at power point is 73.08 {mu}W. The conversion efficiency is 0.7026% and the fill factor is 0.2856 at the power point of the photogalvanic cell. The photogalvanic cell so developed can work for 85.0 min in dark if it is irradiated for 140.0 min i.e. the storage capacity of photogalvanic cell is 60.71%. The effects of different parameters on the electrical output of the photogalvanic cell have been observed. A mechanism has also been proposed for the photogeneration of electrical energy. (author)

  16. On the technical development to minimize the quantity of solid wastes in a uranium conversion

    International Nuclear Information System (INIS)

    Otomura, Keiichiro; Ogura, Yoshikazu; Fujisaki, Sakae

    1987-01-01

    We have developed the new process of treating the waste liquor from a uranium conversion at Ningyo Toge Works PNC, Japan. This process consists of neutralizing precipitation, solid liquid separation, distillation and adsorption. At a neutralizing precipitation step a magnesium oxide is added in the waste liquor containing uranium and fluorine. Most of the uranium and fluorine in the waste liquor precipitate as magnesium compounds. A sulfuric acid is added to the precipitate separated by a filter to dissolve. The resulting solution is then distilled to recover a hydrofluoric acid as a distillate. Uranium is recovered from a residue by an anion exchange method. The recoverd fluorine and uranium are recycled to the main process of conversion. The filtrate separated at the precipitation step is then passed through adsorbing columns. The residual fluorine and uranium in the filtrate were adsorbed and removed by the chelating resine which selectively adsorb the uranium and fluorine. After that the treated waste liquor is discharged out of the plant. This process has merits of being able to minimize the quantity of solid waste in comparison with the conventional process and to recover uranium and fluorine. This process can also be applied to uranium reconversion process from uranium hexafluoride to uranium oxide and to uranium metal production process, which produce the same kind of waste liquor. (author)

  17. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 1: Introduction and summary and general assumptions. [energy conversion systems for electric power plants using coal - feasibility

    Science.gov (United States)

    Beecher, D. T.

    1976-01-01

    Nine advanced energy conversion concepts using coal or coal-derived fuels are summarized. They are; (1) open-cycle gas turbines, (2) combined gas-steam turbine cycles, (3) closed-cycle gas turbines, (4) metal vapor Rankine topping, (5) open-cycle MHD; (6) closed-cycle MHD; (7) liquid-metal MHD; (8) advanced steam; and (9) fuel cell systems. The economics, natural resource requirements, and performance criteria for the nine concepts are discussed.

  18. Conversion of the US State System of Accountancy to be Year 2000 compliant

    International Nuclear Information System (INIS)

    Proco, G.; Brown, S.

    1999-01-01

    The Nuclear Materials Management and Safeguards System (NMMSS) is the US government's state system of accountancy, maintaining current and historical data on the possession, use and transfer of nuclear material. The system is an important tool in maintaining and monitoring accounting data for nuclear materials inventory and transactions and reporting under the US Atomic Energy Act of 1954, as amended, the safeguards agreement between the US and the International Atomic Energy Agency and agreements for cooperation between the US and its international partners for peaceful uses of atomic energy. Accounting information is provided to the system by nuclear facilities under the reporting requirements issued by relevant US government entities: the Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC). The NMMSS is operated for the DOE and the NRC by NAC International, Norcross, Georgia. The state system of accountancy was identified by the US government as a 'mission essential' system, an accounting system considered essential to government missions. As such, the system is held to a high standard of reliability. This system was identified in 1996 by the DOE as a system that should be made Year 2000 compliant at an early date - by March 1999. Very detailed planning for system conversion was necessary including: risk and vulnerability assessments, a comprehensive test plan and a contingency plan to be followed in case the conversion was not completed on time. Actual compliance was accomplished well in advance of March 1999. The conversion was complete, tested and capable of receiving data in the revised format in July 1998. All date fields in the data base are now eight characters, with the year reported in four characters. All incoming data that is only six characters is modified through software into an eight-character format by a default provision in the system. Also, output reports now contain eight-character date fields. If any of the systems that

  19. Design of the steam generator in an energy conversion system based on the aluminum combustion with water

    International Nuclear Information System (INIS)

    Mercati, Stefano; Milani, Massimo; Montorsi, Luca; Paltrinieri, Fabrizio

    2012-01-01

    Highlights: ► Development of a numerical approach for the analysis of a co-generation system based on the aluminum water reaction. ► Construction of system operating maps for estimating the system behavior. ► Comparison of two different designs of the steam generator for the system. ► Definition of the operating range where each configuration provides the best performance. -- Abstract: The paper shows the preliminary design of the superheated steam generator to be used in a novel hydrogen production and energy conversion system based on the combustion of aluminum particles with water. The system is aimed at producing hydrogen and pressurized superheated steam, using the heat released by the Al–H 2 O reaction. The interest on this type of technology arises because of the possibility of obtaining hydrogen with very low pollutant and greenhouse gas emissions, compared to the traditional hydrogen production systems, such as the steam reforming from methane. The analysis of the combustion chamber and the heat recovery system is carried out by means of a lumped and distributed parameter numerical approach. The multi phase and gas mixture theoretical principles are used both to characterize the mass flow rate and the heat release in the combustion chamber and within the heat exchangers in order to relate the steam generator performance to the system operating parameters. Finally, the influence of the steam generator performance on the whole energy conversion system behavior is addressed, with particular care to the evaluation of the total power and efficiency variation with the combustion parameters.

  20. Assessment of control strategies for fault ride through of SCIG-based wind energy conversion systems

    Directory of Open Access Journals (Sweden)

    Manaullah

    2016-01-01

    Full Text Available With increasing penetration of wind energy into the power grid, researchers have started focusing more on control and coordination of wind energy conversion systems (WECS with the other components at system level, especially during fault. It is important to implement a suitable fault ride through control strategy to avoid tripping of the generators when the power system is subjected to voltage dips normally below 90% of nominal voltage. The dips below 90% may lead to a significant loss of generation and frequency collapse, followed by a blackout. This article implements and assesses the methodologies to deal with such situations for squirrel cage induction generator-based wind energy conversion systems employing fully rated power electronic converters. Three distinct control techniques—namely, balanced positive sequence control, positive negative sequence control, and dual current control—have been simulated and applied to grid side converter of SCIG-based WECS. The performance of all the three control strategies has been compared and presented in this work. During this study, the system is subjected to the most common unsymmetrical line to ground (LG fault and most severe symmetrical LLL fault on grid for the purpose of anaysis.

  1. Development and application of a complex numerical model and software for the computation of dose conversion factors for radon progenies.

    Science.gov (United States)

    Farkas, Árpád; Balásházy, Imre

    2015-04-01

    A more exact determination of dose conversion factors associated with radon progeny inhalation was possible due to the advancements in epidemiological health risk estimates in the last years. The enhancement of computational power and the development of numerical techniques allow computing dose conversion factors with increasing reliability. The objective of this study was to develop an integrated model and software based on a self-developed airway deposition code, an own bronchial dosimetry model and the computational methods accepted by International Commission on Radiological Protection (ICRP) to calculate dose conversion coefficients for different exposure conditions. The model was tested by its application for exposure and breathing conditions characteristic of mines and homes. The dose conversion factors were 8 and 16 mSv WLM(-1) for homes and mines when applying a stochastic deposition model combined with the ICRP dosimetry model (named PM-A model), and 9 and 17 mSv WLM(-1) when applying the same deposition model combined with authors' bronchial dosimetry model and the ICRP bronchiolar and alveolar-interstitial dosimetry model (called PM-B model). User friendly software for the computation of dose conversion factors has also been developed. The software allows one to compute conversion factors for a large range of exposure and breathing parameters and to perform sensitivity analyses. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Raw materials evaluation and process development studies for conversion of biomass to sugars and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.; Yang, R.D.; Sciamanna, A.S.; Freitas, R.P.

    1978-06-01

    A range of cellulosic raw materials in the form of agricultural crop residue was analyzed for chemical composition and assessed for potential yields of sugars through chemical pretreatment and enzymatic hydrolysis of these materials. Corn stover was used as a representative raw material for a preliminary process design and economic assessment of the production of sugars and ethanol. With the process as presently developed, 23 gallons of ethanol can be obtained per ton of corn stover at a processing cost of about $1.80 per gallon exclusive of by-product credits. The analysis shows the cost of ethanol to be highly dependent upon (1) the cost of the biomass, (2) the extent of conversion to glucose, (3) enzyme recovery and production cost and (4) potential utilization of xylose. Significant cost reduction appears possible through further research in these directions.

  3. Development of a NIM module for time-to-digital conversion

    International Nuclear Information System (INIS)

    Lin Yanchang; Wang Xiaobin; Chen Shaomin; Gao Yuanning; Jiang Chunhua; Qian Wenbin

    2008-01-01

    A developed single slot wide NIM module for time-to-digital conversion (TDC) is presented in this paper. This TDC module consists of a CPLD based double edge trigger counter with logic function circuit, a high speed comparator based NIM-to-TTL logic level converter, a processor ARM based data access and communication control unit, and voltage regulators for power supply. There are two input groups available, separately for accepting start and stop signal between two input ports or just from the same input port in sequence. With a 50 MHz reference clock, the available input ranges from 0 to 81.91 μs, and the resolution can reach 10 ns level. This module was tested in a muon lifetime measurement experiment, showing good linearity, simple configuration, low power consumption, good reliability, low cost, and easy upgrade as well. (authors)

  4. International Clean Energy System Using Hydrogen Conversion (WE-NET). subtask 5. Development of hydrogen transport/storage technology (development of storage facility for liquid hydrogen); Suiso riyo kokusai clean energy system gijutsu (WE-NET). subtask 5. Suiso yuso chozo gijutsu no kaihatsu (ekitai suiso chozo setsubi no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    As a part of the WE-NET project, the storage facility for a large amount of liquid hydrogen (LH) was studied. Gasification loss caused by heat input of LH delivery pumps was studied for liquefaction and power generation bases assuming an pump efficiency of 70%, and the total heat and mass balance such as interface conditions for calculating the amount of boil-off gas was reviewed. The target storage capacity of 50,000m{sup 3} was reasonable, however, the performance of loading arms should be examined. The capacity around 5,000m{sup 3} of coastal localized bases was reasonable for control delivery loss caused by coastal tanker or LH container system to 2.6%. The capacity of 500m{sup 3} was suitable for inland bases, resulting in the loss of 1.2%. The concept design of the storage tank of 50,000m{sup 3} extracted confirmation of low-temperature characteristics of adiabatic materials and structures, and development of leakage inspection technology and vacuum holding technology as issues. The concept design of the underground storage tank showed that the material specifications for LNG ones are applicable to it by using proper adiabatic structures. 4 refs., 72 figs., 27 tabs.

  5. Frequency-agile THz-wave generation and detection system using nonlinear frequency conversion at room temperature.

    Science.gov (United States)

    Guo, Ruixiang; Ikar'i, Tomofumi; Zhang, Jun; Minamide, Hiroaki; Ito, Hiromasa

    2010-08-02

    A surface-emitting THz parametric oscillator is set up to generate a narrow-linewidth, nanosecond pulsed THz-wave radiation. The THz-wave radiation is coherently detected using the frequency up-conversion in MgO: LiNbO(3) crystal. Fast frequency tuning and automatic achromatic THz-wave detection are achieved through a special optical design, including a variable-angle mirror and 1:1 telescope devices in the pump and THz-wave beams. We demonstrate a frequency-agile THz-wave parametric generation and THz-wave coherent detection system. This system can be used as a frequency-domain THz-wave spectrometer operated at room-temperature, and there are a high possible to develop into a real-time two-dimensional THz spectral imaging system.

  6. Permanent Magnet Synchronous Generator Driven Wind Energy Conversion System Based on Parallel Active Power Filter

    Directory of Open Access Journals (Sweden)

    FERDI Brahim

    2014-05-01

    Full Text Available This paper proposes a novel application of the instantaneous P-Q theory in a wind energy conversion system (WECS. The proposed WECS is formed by permanent magnet synchronous generator (PMSG wind turbine system connected to the grid through parallel active power filter (PAPF. PAPF uses the generated wind energy to feed loads connected at the point of common coupling (PPC, compensates current harmonics and injects the excess of this energy into the grid using P-Q theory as control method. To demonstrate the feasibility and the performance of the proposed control scheme, simulation of this wind system has been realized using MATLAB/SIMULINK software. Simulation results show the accuracy and validity of the proposed control scheme for the PMSGPAPF system.

  7. Final design of a free-piston hydraulic advanced Stirling conversion system

    Science.gov (United States)

    Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    1991-01-01

    Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

  8. Dynamic modeling and sensitivity analysis of solar thermal energy conversion systems

    Science.gov (United States)

    Hamilton, C. L.

    1977-01-01

    Since the energy input to solar thermal conversion systems is both time variant and probabilistic, it is unlikely that simple steady-state methods for estimating lifetime performance will provide satisfactory results. The work described here uses dynamic modeling to begin identifying what must be known about input radiation and system dynamic characteristics to estimate performance reliably. Daily operation of two conceptual solar energy systems was simulated under varying operating strategies with time-dependent radiation intensity ranging from smooth input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours. Integrated daily system output and efficiency were functions of both level and dynamic characteristics of insolation. Sensitivity of output to changes in total input was greater than one.

  9. Final design of a free-piston hydraulic advanced Stirling conversion system

    Science.gov (United States)

    Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

  10. Optical signal demultiplexing and conversion in the fullerene–oligothiophene–CdS system

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowska, Kornelia [Polish Academy of Science, Institute of Molecular Physics, ul. Smoluchowskiego 17, 60-179 Poznań (Poland); Podborska, Agnieszka; Kwolek, Przemysław [AGH University of Science and Technology, Faculty of Non-Ferrous Metals, al. A. Mickiewicza 30, 30-059 Kraków (Poland); Kim, Tae-Dong; Lee, Kwang-Sup [Department of Advanced Materials, Hannam University, Daejeon 305-811 (Korea, Republic of); Szaciłowski, Konrad, E-mail: szacilow@agh.edu.pl [AGH University of Science and Technology, Faculty of Non-Ferrous Metals, al. A. Mickiewicza 30, 30-059 Kraków (Poland); Jagiellonian University, Faculty of Chemistry, ul. R. Ingardena 3, 30-60 Kraków (Poland)

    2014-11-15

    Graphical abstract: - Highlights: • Photoelectrochemical photocurrent switching (PEPS) effect in the C{sub 60} derivatives system. • Systems for optical-to-electrical signal conversion. • Fullerene–oligothiophene dyad system as 1:2-demultiplexer. - Abstract: We report the photoelectrochemical photocurrent switching (PEPS) effect in the system based on a C{sub 60} derivatives and nanostructured cadmium sulfide. Rapid and efficient photocurrent switching upon changes of the electrode potential was observed. This process relies on the photocurrent generation by semiconducting particles and interfacial electron transfer reactions governed by the redox chemistry of fullerene derivatives (fullerene–oligothiophene dyads) with molecular oxygen as a final electron acceptor. Surprisingly, fullerene derivatives without thiophene moieties were much less efficient as CdS modifiers. These peculiar photoelectrochemical properties were applied for construction of an optoelectronic logic device.

  11. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels Conversion Pathway: Fast Pyrolysis and Hydrotreating Bio-Oil Pathway "The 2017 Design Case"

    Energy Technology Data Exchange (ETDEWEB)

    Kevin L. Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J. Bonner; Garold L. Gresham; J. Richard Hess; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2014-01-01

    The U.S. Department of Energy promotes the production of liquid fuels from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass sustainable supply, logistics, conversion, and overall system sustainability. As part of its involvement in this program, Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL quantified and the economics and sustainability of moving biomass from the field or stand to the throat of the conversion process using conventional equipment and processes. All previous work to 2012 was designed to improve the efficiency and decrease costs under conventional supply systems. The 2012 programmatic target was to demonstrate a biomass logistics cost of $55/dry Ton for woody biomass delivered to fast pyrolysis conversion facility. The goal was achieved by applying field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model.

  12. Developing systems engineers

    CSIR Research Space (South Africa)

    Goncalves, D

    2008-07-01

    Full Text Available will have rendered him incapable of dealing with the majority of problems that will face him.” (Quoted in [12]). UP has applied the SPICES model, proposed by Harden et al. [12], for developing their medical curriculum. Some aspects of the model... are useful to developing systems engineers and will be considered in SE terms at a relevant level of detail. The SPICES model is contrasted against traditional medical curriculum approaches in TABLE 1. These are two extremes on a continuum. Traditional...

  13. Mobile systems development

    DEFF Research Database (Denmark)

    Hosbond, Jens Henrik

    2005-01-01

    and how are they dealt with? Analysis of the empirical data is done following a structured and inductive approach. A framework showing the segmentation of the mobile industry into five layers is proposed and challenges are presented according to two dimensions, namely a business dimension......This paper takes a systems development perspective on mobility, building on preliminary findings of an on-going multiple case study covering 7 companies. The questions driving this paper are: What are the challenges facing development practice in the mobile industry, how do they affect practice...

  14. Environmental Monitoring Techniques and Equipment related to the installation and operation of Marine Energy Conversion Systems

    International Nuclear Information System (INIS)

    Scanu, Sergio; Carli, Filippo Maria; Piermattei, Viviana; Bonamano, Simone; Paladini de Mendoza, Francesco; Marcelli, Marco; Peviani, Maximo Aurelio; Dampney, Keith; Norris, Jennifer

    2015-01-01

    Results of activities under project Marine Renewables Infrastructure Network for Emerging Energy Technologies (MaRINET) are reported, which led to DEMTE, a database, created on the basis of standardized monitoring of the marine environment during installation, operation and decommissioning of Marine Energy Conversion Systems. Obtained with the consortium partners’ available techniques and equipment, the database shows that such instruments cover all identified marine environmental compartments, despite the lack of underwater vehicles and the reduced skills in using satellite technologies. These weaknesses could be overcome by an accurate planning of equipment, techniques and knowledge sharing. The approach here presented also leads to an effective analysis even in non-marine contexts

  15. Applying systemic functional linguistics to conversations with dementia: the linguistic construction of relationships between participants.

    Science.gov (United States)

    Müller, Nicole; Mok, Zaneta

    2012-02-01

    Social isolation in dementia is a growing concern as the incidence and prevalence of dementing conditions is on the rise in many societies. Positive social interactions, which foster the construction and enactment of positive interpersonal relationships and therefore positive discursive identities, make an important contribution to emotional well-being. In this article, we investigate how two women diagnosed with dementia of the Alzheimer's type use language to relate to each other and two visiting graduate students. We use Systemic Functional Linguistics as an analytical framework, specifically investigating the use of vocatives and naming, and conversational moves and exchanges. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. Line filter design of parallel interleaved VSCs for high power wind energy conversion systems

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2015-01-01

    The Voltage Source Converters (VSCs) are often connected in parallel in a Wind Energy Conversion System (WECS) to match the high power rating of the modern wind turbines. The effect of the interleaved carriers on the harmonic performance of the parallel connected VSCs is analyzed in this paper...... limit. In order to achieve the desired filter performance with optimal values of the filter parameters, the use of a LC trap branch with the conventional LCL filter is proposed. The expressions for the resonant frequencies of the proposed line filter are derived and used in the design to selectively...

  17. Recent laser physics results on power balance and frequency conversion with the Phebus laser system

    International Nuclear Information System (INIS)

    Thiell, G.; Paye, J.; Graillot, H.; Mathieu, F.; Boscheron, A.; Reynier, F.; Estraillier, P.; Bruneau, J.L.

    1995-01-01

    The Phebus laser system has been mainly devoted to plasma physics experiments such as implosion and hydrodynamical instability studies since it was completed in 1985. But during the last two years, the three Phebus beamlines (2 main beams and a backlighter beam) are also utilized to perform some laser physics studies in view of the Megajoule laser project. The goal of the laser physics experiments conducted at the Phebus facility in 1994--1995 is to validate some design issues of the Megajoule Laser project concerning namely power balance and frequency conversion

  18. Integrated automation system for a pilot plant for energy conversion using PEMFCs

    International Nuclear Information System (INIS)

    Culcer, Mihai; Iliescu, Mariana; Raceanu, Mircea; Stanciu, Vasile; Stefanescu, Ioan; Enache, Adrian; Lazaro, Pavel Gabriel; Lazaroiu, Gheorghe; Badea, Adrian

    2007-01-01

    Based on Hydrogen and Fuel Cells researches and technological capabilities achieved in the National R and D Programs, ICIT Rm. Valcea built an experimental-demonstrative pilot plant for energy conversion using hydrogen PEMFCs. This pilot plant consists of a fuel processor based on steam methane reforming (SMR) process, a hydrogen purification unit, a PEM fuel cells stack (FCS) and a power electronics unit. The paper deals with the dedicated controlling system that provides automated data acquisition, manual or on-line operational control, gas management, humidification, temperature and flow controls. (authors)

  19. Survey of Historical and Current Site Selection Techniques for the Placement of Small Wind Energy Conversion Systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    The purpose of this study was to identify and document methods and practices used in siting of wind energy conversion systems (WECS). The study covers the period from the early 1900s to the present day.

  20. Energy efficiency system development

    Science.gov (United States)

    Leman, A. M.; Rahman, K. A.; Chong, Haw Jie; Salleh, Mohd Najib Mohd; Yusof, M. Z. M.

    2017-09-01

    By subjecting to the massive usage of electrical energy in Malaysia, energy efficiency is now one of the key areas of focus in climate change mitigation. This paper focuses on the development of an energy efficiency system of household electrical appliances for residential areas. Distribution of Questionnaires and pay a visit to few selected residential areas are conducted during the fulfilment of the project as well as some advice on how to save energy are shared with the participants. Based on the collected data, the system developed by the UTHM Energy Team is then evaluated from the aspect of the consumers' behaviour in using electrical appliances and the potential reduction targeted by the team. By the end of the project, 60% of the participants had successfully reduced the electrical power consumption set by the UTHM Energy Team. The reasons for whether the success and the failure is further analysed in this project.

  1. Adoption of nitrogen power conversion system for small scale ultra-long cycle fast reactor eliminating intermediate sodium loop

    International Nuclear Information System (INIS)

    Seo, Seok Bin; Seo, Han; Bang, In Cheol

    2016-01-01

    Highlights: • N 2 power conversion system for both safety and thermal performance aspects. • Sensitivity studies of several controlled parameters on N 2 power conversion system. • The elimination of the intermediate loop increased the cycle thermal efficiency. • The elimination of the intermediate loop expects economic advantages. - Abstract: As one of SFRs, the ultra-long cycle fast reactor with a power rating of 100 MW e (UCFR-100) was introduced for a 60-year operation. As an alternative to the traditional steam Rankine cycle for the power conversion system, gas based Brayton cycle has been considered for UCFR-100. Among Supercritical CO 2 (S-CO 2 ), Helium (He), Nitrogen (N 2 ) as candidates for the power conversion system for UCFR-100, an N 2 power conversion system was chosen considering both safety and thermal performance aspects. The elimination of the intermediate sodium loop could be achieved due to the safety and stable characteristics of nitrogen working fluid. In this paper, sensitivity studies with respect to several controlled parameters on N 2 power conversion system were performed to optimize the system. Furthermore, the elimination of the intermediate loop was evaluated with respect to its impact on the thermodynamic performance and other aspects.

  2. Four-dimensional conversion for spiritual leadership development: A missiological approach for African churches

    Directory of Open Access Journals (Sweden)

    Kalemba Mwambazambi

    2014-02-01

    Full Text Available The process of a four-dimensional conversion and/or transformation strives in helping the leadership of an organisation, especially such as the church, with practical ways that may lead to the development of an effective leadership by observing the four important aspects of human spirituality as elaborated on in the article. The spiritual, intellectual, moral and socio-political dimensions of the transformation can be catered for so that the complete inner being of humans, as well as their social and political attitudes and behaviours, can equally be transformed to maximum spiritual, personal and socio-political profitability. Mutombo-Mukendi demonstrates that the need for a spiritual leadership that can contribute to an effective transformation of Africa is dire, both for the church and the larger community. The real challenge is how to develop such leadership. This article provides intentional and practical ways that may lead to the development of the needed leadership. Four-dimensional transformation of people can be planned and carried out both in the church arena and in the surrounding communities. Skills development and transfer can also take place when skilled people from the church work with unskilled people from the community.

  3. Flexible Mode Control of Grid Connected Wind Energy Conversion System Using Wavelet

    Directory of Open Access Journals (Sweden)

    Bhavna Jain

    2015-01-01

    Full Text Available Small wind turbine systems offer services to critical loads during grid faults and also connected back to grid in normal condition. The connection of a wind energy conversion system to the grid requires a robust phase locked loop (PLL and continuous monitoring of the grid conditions such as overvoltage, undervoltage, overfrequency, underfrequency, and grid outages. This paper describes a flexible control operation to operate a small wind turbine in both stand-alone mode via planned islanding and grid connected mode as well. In particular, a proper monitoring and control algorithm is required for transition between the modes. A wavelet based energy function is used for detection of grid disturbances as well as recovery of grid so that transition between the modes is made. To obtain good power quality LCL filter is used to reduce ripples. PLL is used for synchronization whenever mode changes from stand-alone to grid connected. Simulation results from a 10 kW wind energy conversion system are included to show the usefulness of the proposed methods. The control method is tested by generated gate pulses for single phase bridge inverter using field programmable gate array (FPGA.

  4. Development an Automatic Speech to Facial Animation Conversion for Improve Deaf Lives

    Directory of Open Access Journals (Sweden)

    S. Hamidreza Kasaei

    2011-05-01

    Full Text Available In this paper, we propose design and initial implementation of a robust system which can automatically translates voice into text and text to sign language animations. Sign Language
    Translation Systems could significantly improve deaf lives especially in communications, exchange of information and employment of machine for translation conversations from one language to another has. Therefore, considering these points, it seems necessary to study the speech recognition. Usually, the voice recognition algorithms address three major challenges. The first is extracting feature form speech and the second is when limited sound gallery are available for recognition, and the final challenge is to improve speaker dependent to speaker independent voice recognition. Extracting feature form speech is an important stage in our method. Different procedures are available for extracting feature form speech. One of the commonest of which used in speech
    recognition systems is Mel-Frequency Cepstral Coefficients (MFCCs. The algorithm starts with preprocessing and signal conditioning. Next extracting feature form speech using Cepstral coefficients will be done. Then the result of this process sends to segmentation part. Finally recognition part recognizes the words and then converting word recognized to facial animation. The project is still in progress and some new interesting methods are described in the current report.

  5. Environmental Control System Development

    Science.gov (United States)

    Flores Arroyo, Elvin A.

    2018-01-01

    Since before the first men landed on the moon, human beings have aspired to reach farther into space, to discover and answer the great mysteries that exist beyond imagination. To reach where no one has gone before. To able to see all the wonderful things that can be found in space and that only satellites have revealed to us during all this time. Considering the last trip to the moon, mankind has been evolving and improving their technology to reach destinations whose distances had been impossible to transit. To reach that goal, the National Aeronautics and Space Administration (NASA) has designed and developed the largest and most powerful rocket ever created by the human race, the Space Launch System - better known as the SLS. To be able to send this large rocket to space, Kennedy Space Center (KSC) is doing upgrades to their existing facilities and equipment. At Launch Pad 39B, they are setting up a new Environmental Control System (ECS) developed to supply the rocket with the correct gases and mixtures that will be needed for the rocket to launch. The ECS is similar to an air conditioning unit. The main functionality of it is to supply the SLS with the correct gas mixture for it to launch. Also the ECS has been required to reduce or eliminate the possibility of a complete system failure. The system is part of the Ground Support Equipment (GSE) for the SLS that will be going to the Moon and Mars.

  6. An assessment of dynamic energy conversion systems for terrestrial radioisotope heat sources

    International Nuclear Information System (INIS)

    Thayer, G.R.

    1985-01-01

    The use of dynamic conversion systems to convert to electricity the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source is examined. Brayton Cycle, three Organic Rankine systems (Barber-Nichols/ORMAT, Sundstrand, and TRW concepts), Organic Rankine plus thermoelectrics, and Stirling Engine systems were studied. The systems were ranked for a North Warning System mission using a Los Alamos Multi-Attribute Decision Theory code. Three different heat source designs were used: Case I with a beginning of life (BOL) source temperature of 640 0 C, Case II with a BOL source temperature of 745 0 C, and Case III with a BOL source temperature of 945 0 C. The Stirling Engine system was the top-ranked system for Cases I and II, closely followed by the ORC systems in Case I and ORC and thermoelectrics in Case II. The Brayton-Cycle system was top-ranked for Case III, with the Stirling Engine system a close second

  7. Incentives and market development to establish sustainable biomass systems

    International Nuclear Information System (INIS)

    Matteson Gary, C.

    2009-01-01

    Business-as-usual is not acceptable when it comes to the future for biomass-to-energy/product conversion industry. Incentives and market development need to be applied to guide the owners and operators towards the sustainable practices. Sustainability for biomass is defined to be future energy fuels and bio products that are secure, renewable, and accessible locally, affordable, and pollution free. Intensives are required to convert biomass-to-energy/product conversion systems that are not sustainable into sustainable formats. (Author)

  8. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Ra; Min, Byung Il; Park, Kihyun; Yang, Byung Mo; Suh, Kyung Suk [Nuclear Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-12-15

    The International Commission on Radiological Protection (ICRP) recommendations and the Federal Guidance Report (FGR) published by the U.S. Environmental Protection Agency (EPA) have been widely applied worldwide in the fields of radiation protection and dose assessment. The dose conversion coefficients of the ICRP and FGR are widely used for assessing exposure doses. However, before the coefficients are used, the user must thoroughly understand the derivation process of the coefficients to ensure that they are used appropriately in the evaluation. The ICRP provides recommendations to regulatory and advisory agencies, mainly in the form of guidance on the fundamental principles on which appropriate radiological protection can be based. The FGR provides federal and state agencies with technical information to assist their implementation of radiation protection programs for the U.S. population. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR is reviewed in this study. A thorough understanding of their background is essential for the proper use of dose conversion coefficients. The FGR dose assessment system was strongly influenced by the ICRP and the U.S. National Council on Radiation Protection and Measurements (NCRP), and is hence consistent with those recommendations. Moreover, the ICRP and FGR both used the scientific data reported by Biological Effects of Ionizing Radiation (BEIR) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) as their primary source of information. The difference between the ICRP and FGR lies in the fact that the ICRP utilized information regarding a population of diverse races, whereas the FGR utilized data on the American population, as its goal was to provide guidelines for radiological protection in the US. The contents of this study are expected to be utilized as basic research material in the areas of radiation protection and dose assessment.

  9. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR

    International Nuclear Information System (INIS)

    Kim, So Ra; Min, Byung Il; Park, Kihyun; Yang, Byung Mo; Suh, Kyung Suk

    2016-01-01

    The International Commission on Radiological Protection (ICRP) recommendations and the Federal Guidance Report (FGR) published by the U.S. Environmental Protection Agency (EPA) have been widely applied worldwide in the fields of radiation protection and dose assessment. The dose conversion coefficients of the ICRP and FGR are widely used for assessing exposure doses. However, before the coefficients are used, the user must thoroughly understand the derivation process of the coefficients to ensure that they are used appropriately in the evaluation. The ICRP provides recommendations to regulatory and advisory agencies, mainly in the form of guidance on the fundamental principles on which appropriate radiological protection can be based. The FGR provides federal and state agencies with technical information to assist their implementation of radiation protection programs for the U.S. population. The system of radiation dose assessment and dose conversion coefficients in the ICRP and FGR is reviewed in this study. A thorough understanding of their background is essential for the proper use of dose conversion coefficients. The FGR dose assessment system was strongly influenced by the ICRP and the U.S. National Council on Radiation Protection and Measurements (NCRP), and is hence consistent with those recommendations. Moreover, the ICRP and FGR both used the scientific data reported by Biological Effects of Ionizing Radiation (BEIR) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) as their primary source of information. The difference between the ICRP and FGR lies in the fact that the ICRP utilized information regarding a population of diverse races, whereas the FGR utilized data on the American population, as its goal was to provide guidelines for radiological protection in the US. The contents of this study are expected to be utilized as basic research material in the areas of radiation protection and dose assessment

  10. Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products.

    Directory of Open Access Journals (Sweden)

    Dennis G A B Oonincx

    Full Text Available A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids, were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food.

  11. Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products

    Science.gov (United States)

    Oonincx, Dennis G. A. B.; van Broekhoven, Sarah; van Huis, Arnold; van Loon, Joop J. A.

    2015-01-01

    A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids), were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food. PMID:26699129

  12. Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products.

    Science.gov (United States)

    Oonincx, Dennis G A B; van Broekhoven, Sarah; van Huis, Arnold; van Loon, Joop J A

    2015-01-01

    A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids), were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food.

  13. FM-AM Conversion Induced by Polarization Mode Dispersion in Fiber Systems

    International Nuclear Information System (INIS)

    Xiao-Dong, Huang; Sheng-Zhi, Zhao; Jian-Jun, Wang; Ming-Zhong, Li; Dang-Peng, Xu; Hong-Huan, Lin; Rui, Zhang; Ying, Deng; Xiao-Min, Zhang

    2010-01-01

    The conversion of the frequency modulated pulse induced from frequency modulation (FM) to amplitude modulation (AM) by the polarization mode dispersion (PMD) is theoretically and experimentally investigated. When there is no polarizer at the output end of a fiber system, the amplitude modulation depth is stable by 8%. Random amplitude modulation is observed when a polarizer is placed at the output end of the fiber system. The observed minimum and maximum modulation depths in our experiment are 5% and 80%, respectively. Simulation results show that the amplitude modulation is stable by 4% induced mainly by group velocity dispersion (GVD) when there is no polarizer, and the amplitude modulation depth displays the random variation character induced by the GVD and PMD. Lastly, a new fiber system scheme is proposed and little amplitude modulation is observed at the top of the output pulse

  14. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...... constraints in both systems. An iterative method is proposed to deal with the nonlinearity in the proposed model. The models of the natural gas and power system are linearized in every iterative step. Simulation results demonstrate the effectiveness of the approach. Applicability of the proposed method...... is tested in the sample case. Finally, the effect of Power to Gas (P2G) on the daily economic dispatch is also investigated....

  15. Does laser diode irradiation improve the degree of conversion of simplified dentin bonding systems?

    Directory of Open Access Journals (Sweden)

    Leticia Ferreira de Freitas BRIANEZZI

    Full Text Available Abstract Simplified dentin-bonding systems are clinically employed for most adhesive procedures, and they are prone to hydrolytic degradation. Objective This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC, water sorption (WS, and water solubility (WSB of these bonding systems in an attempt to improve their physico-mechanical resistance. Material and Methods Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU]. Square-shaped specimens were prepared and assigned into 4 groups (n=5: SB and SU (control groups – no laser irradiation and SB-L and SU-L [SB and SU laser (L – irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5 of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10 were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm, irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2. Results Laser irradiation immediately before photopolymerization increased the DC (% of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3, only the dentin bonding system (DBS was a significant factor (pSU. Conclusion Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility.

  16. Novel high efficient speed sensorless controller for maximum power extraction from wind energy conversion systems

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2016-01-01

    Highlights: • Novel sensorless MPPT technique without drawbacks of other sensor/sensorless methods. • Tracking the actual MPP of WECSs, no tracking the MPP of their wind turbines. • Actually extracting the highest output power from WECSs. • Novel MPPT technique having the MPPT efficiency more than 98.5% for WECSs. • Novel MPPT technique having short convergence time for WECSs. - Abstract: In this study, a novel high accurate sensorless maximum power point tracking (MPPT) method is proposed. The technique tracks the actual maximum power point of a wind energy conversion system (WECS) at which maximum output power is extracted from the system, not the maximum power point of its wind turbine at which maximum mechanical power is obtained from the turbine, so it actually extracts the highest output power from the system. The technique only uses input voltage and current of the converter used in the system, and neither needs any speed sensors (anemometer and tachometer) nor has the drawbacks of other sensor/sensorless based MPPT methods. The technique has been implemented as a MPPT controller by constructing a WECS. Theoretical results, the technique performance, and its advantages are validated by presenting real experimental results. The real static-dynamic response of the MPPT controller is experimentally obtained that verifies the proposed MPPT technique high accurately extracts the highest instant power from wind energy conversion systems with the MPPT efficiency of more than 98.5% and a short convergence time that is only 25 s for the constructed system having a total inertia and friction coefficient of 3.93 kg m 2 and 0.014 N m s, respectively.

  17. Continuous mercury monitors conditioning/conversion systems : what we have learned

    Energy Technology Data Exchange (ETDEWEB)

    Laudal, D.L.; Dunham, G.E.; Thompson, J.S. [North Dakota Univ., Grand Forks, ND (United States). Energy and Environmental Research Center

    2006-07-01

    The challenges of continuous mercury monitoring (CMM) in flue gas were discussed with reference to conditioning/conversion systems where a sample of gas of an unknown composition is conditioned to elemental mercury. Flue gas composition varies greatly depending on coal type and plant configuration. The widely used wet-chemistry systems remove interfering gas constituents by bubbling the sample gas through reactive solutions. Some concerns with the wet systems are the amount of chemicals used and the volume of the waste generated; capture of CO{sub 2} which affects the sample volume; mercury hang-up; condensation of flue gas constituents; and, potential for unidentified chemical reactions. The advantages of dry systems were discussed, such as the ability to convert all of the mercury present in the flue gas to elemental mercury. Some of the main concerns with dry systems are that some systems will require a correction for moisture, which means installing a moisture monitor. Dry systems can also be prone to mercury hang-up and calibration of some of the dilution systems remains a concern. The systems can also be susceptible a significant decrease in catalyst life. figs.

  18. Preliminary Study of Printed Circuit Heat Exchanger (PCHE) for various power conversion systems for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jinsu; Baik, Seungjoon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    The steam-Rankine cycle was the most widely used power conversion system for a nuclear power plant. The size of the heat exchanger is important for the modulation. Such a challenge was conducted by Kang et al. They change the steam generator type for the SMART from helical type heat exchanger to Printed Circuit Heat Exchanger (PCHE). Recently, there has been a growing interest in the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle as the most promising power conversion system. The reason is high efficiency with simple layout and compact power plant due to small turbomachinery and compact heat exchanger technology. That is why the SCO{sub 2} Brayton cycle can enhance the existing advantages of Small Modular Reactor (SMR) like SMART, such as reduction in size, capital cost, and construction period. Thermal hydraulic and geometric parameters of a PCHE for the S-CO{sub 2} power cycle coupled to SMART. The results show that the water - CO{sub 2} printed circuit heat exchanger size is smaller than printed circuit steam generator for the superheated steam Rankine cycle. This results show the potential benefit of using the S-CO-2 Brayton power cycle to a water-cooled small modular reactor.

  19. Adaptability of Brayton cycle conversion systems to fast, epithermal and thermal spectrum space nuclear reactors

    International Nuclear Information System (INIS)

    Tilliette, Z.P.

    1988-01-01

    The two French Government Agencies C.N.E.S. (Centre National d'Etudes Spatiales) and C.E.A. (Commissariat a l'Energie Atomique) are carrying out joint preliminary studies on space nuclear power systems for future ARIANE 5 launch vehicle applications. The Brayton cycle is the reference conversion system, whether the heat source is a liquid metal-cooled (NaK, Na or Li) reactor or a gas-cooled direct cycle concept. The search for an adequate utilization of this energy conversion means has prompted additional evaluations featuring the definition of satisfactory cycle conditions for these various kinds of reactor concepts. In addition to firstly studied fast and epithermal spectrum ones, thermal spectrum reactors can offer an opportunity of bringing out some distinctive features of the Brayton cycle, in particular for the temperature conditioning of the efficient metal hydrides (ZrH, Li/sub 7/H) moderators. One of the purposes of the paper is to confirm the potential of long lifetime ZrH moderated reactors associated with a gas cycle and to assess the thermodynamical consequences for both Nak(Na)-cooled or gas-cooled nuclear heat sources. This investigation is complemented by the definition of appropriate reactor arrangements which could be presented on a further occasion

  20. Geological disposal system development

    International Nuclear Information System (INIS)

    Kang, Chul Hyung; Kuh, J. E.; Kim, S. K. and others

    2000-04-01

    Spent fuel inventories to be disposed of finally and design base spent fuel were determined. Technical and safety criteria for a geological repository system in Korea were established. Based on the properties of spent PWR and CANDU fuels, seven repository alternatives were developed and the most promising repository option was selected by the pair-wise comparison method from the technology point of view. With this option preliminary conceptual design studies were carried out. Several module, e.g., gap module, congruent release module were developed for the overall assessment code MASCOT-K. The prominent overseas databases such as OECD/NEA FEP list were are fully reviewed and then screened to identify the feasible ones to reflect the Korean geo-hydrological conditions. In addition to this the well known scenario development methods such as PID, RES were reviewed. To confirm the radiological safety of the proposed KAERI repository concept the preliminary PA was pursued. Thermo-hydro-mechanical analysis for the near field of repository were performed to verify thermal and mechanical stability for KAERI repository system. The requirements of buffer material were analyzed, and based on the results, the quantitative functional criteria for buffer material were established. The hydraulic and swelling property, mechanical properties, and thermal conductivity, the organic carbon content, and the evolution of pore water chemistry were investigated. Based on the results, the candidate buffer material was selected

  1. Geological disposal system development

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Chul Hyung; Kuh, J. E.; Kim, S. K. and others

    2000-04-01

    Spent fuel inventories to be disposed of finally and design base spent fuel were determined. Technical and safety criteria for a geological repository system in Korea were established. Based on the properties of spent PWR and CANDU fuels, seven repository alternatives were developed and the most promising repository option was selected by the pair-wise comparison method from the technology point of view. With this option preliminary conceptual design studies were carried out. Several module, e.g., gap module, congruent release module were developed for the overall assessment code MASCOT-K. The prominent overseas databases such as OECD/NEA FEP list were are fully reviewed and then screened to identify the feasible ones to reflect the Korean geo-hydrological conditions. In addition to this the well known scenario development methods such as PID, RES were reviewed. To confirm the radiological safety of the proposed KAERI repository concept the preliminary PA was pursued. Thermo-hydro-mechanical analysis for the near field of repository were performed to verify thermal and mechanical stability for KAERI repository system. The requirements of buffer material were analyzed, and based on the results, the quantitative functional criteria for buffer material were established. The hydraulic and swelling property, mechanical properties, and thermal conductivity, the organic carbon content, and the evolution of pore water chemistry were investigated. Based on the results, the candidate buffer material was selected.

  2. Basic policy of maintenance for the power conversion system of the gas turbine high temperature reactor 300 (GTHTR300)

    International Nuclear Information System (INIS)

    Kosugiyama, Shinichi; Takizuka, Takakazu; Kunitomi, Kazuhiko; Yan, Xing; Katanishi, Shoji; Takada, Shoji

    2003-01-01

    Basic policy of maintenance was determined for major equipment in the power conversion system of the Gas Turbine High Temperature Reactor 300 (GTHTR300). It was developed based on the current maintenance practice in Light Water Reactors (LWRs), High Temperature Engineering Test Reactor (HTTR) and conventional combined cycle power plants while taking into account of unique design features of GTHTR300. First, potential degradation phenomena in operations were identified and corresponding maintenance approaches were proposed for the equipment. Such degradations encountered typically in LWRs as corrosion, erosion and stress corrosion cracking are unlikely to occur since the working fluid of GTHTR300 is inert helium. Main causes of the degradations are high operating temperature and pressure. The gas turbine, compressor, generator, control valves undergo opening and dismantling maintenance in a suitable time interval. The power conversion vessel, heat exchanger vessel, primary system piping and heat exchanging tubes of precooler are subjected to in-service inspections similar to those done in LWRs. As turbine blades represent the severest material degradation because of their high-temperature and high-stress operating conditions, a lifetime management scheme was suggested for them. The longest interval of open-casing maintenance of the gas turbine is estimated to be six to seven years from technical point of view. Present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  3. Comparison of simulations and offshore measurement data of a prototype of a floating combined wind and wave energy conversion system

    DEFF Research Database (Denmark)

    Yde, Anders; Larsen, Torben J.; Hansen, Anders Melchior

    2015-01-01

    In this paper, results from comparisons of simulations and measured offshore data from a floating combined wind and wave energy conversion system are presented. The device is a downscaled prototype that consists of a floating platform equipped with ten wave energy absorbers and three wind turbines....... The numerical model of the platform is based on the aeroelastic code, HAWC2, developed by DTU Wind Energy, which is coupled with a special external system that reads the output generated directly by the wave analysis software, WAMIT. The model also includes models for the dynamic mooring lines as well...... as the turbines non-linear yaw and teeter motion behavior. The main focus on the comparison will be on the statistical trends of the platform motion, mooring loads and turbine loads in measurements and simulations during different operational conditions such as increasing wind speed, wave height and wind...

  4. Design Concepts for RF-DC Conversion in Particle Accelerator Systems

    CERN Document Server

    Caspers, F; Grudiev, A; Sapotta, H

    2010-01-01

    In many particle accelerators considerable amounts of RF power reaching the megawatt level are converted into heat in dummy loads. After an overview of RF power in the range 200 MHz to 1 GHz dissipated at CERN we discuss several developments that have come up in the past using vacuum tube technology for RF-DC conversion. Amongst those the developments of the cyclotron wave converter CWC appears most suitable. With the availability of powerful Schottky diodes the solid state converter aspect has to be addressed as well. One of the biggest problems of Schottky diode based structures is the junction capacity. GaAs and GaN Schottky diodes show a significant reduction of this junction capacity as compared to silicon. Small rectenna type converter units which have been already developed for microwave powered helicopters can be used in waveguides or with coaxial power dividers.

  5. Hybrid photovoltaic-thermoelectric system for concentrated solar energy conversion: Experimental realization and modeling

    Science.gov (United States)

    Beeri, Ofer; Rotem, Oded; Hazan, Eden; Katz, Eugene A.; Braun, Avi; Gelbstein, Yaniv

    2015-09-01

    An experimental demonstration of the combined photovoltaic (PV) and thermoelectric conversion of concentrated sunlight (with concentration factor, X, up to ˜300) into electricity is presented. The hybrid system is based on a multi-junction PV cell and a thermoelectric generator (TEG). The latter increases the electric power of the system and dissipates some of the excessive heat. For X ≤ 200, the system's maximal efficiency, ˜32%, was mostly due to the contribution from the PV cell. With increasing X and system temperature, the PV cell's efficiency decreased while that of the TEG increased. Accordingly, the direct electrical contribution of the TEG started to dominate in the total system power, reaching ˜20% at X ≈ 290. Using a simple steady state finite element modeling, the cooling effect of the TEG on the hybrid system's efficiency was proved to be even more significant than its direct electrical contribution for high solar concentrations. As a result, the total efficiency contribution of the TEG reached ˜40% at X ≈ 200. This suggests a new system optimization concept that takes into account the PV cell's temperature dependence and the trade-off between the direct electrical generation and cooling capabilities of the TEG. It is shown that the hybrid system has a real potential to exceed 50% total efficiency by using more advanced PV cells and TE materials.

  6. Automatic conversational scene analysis in children with Asperger syndrome/high-functioning autism and typically developing peers.

    Science.gov (United States)

    Tavano, Alessandro; Pesarin, Anna; Murino, Vittorio; Cristani, Marco

    2014-01-01

    Individuals with Asperger syndrome/High Functioning Autism fail to spontaneously attribute mental states to the self and others, a life-long phenotypic characteristic known as mindblindness. We hypothesized that mindblindness would affect the dynamics of conversational interaction. Using generative models, in particular Gaussian mixture models and observed influence models, conversations were coded as interacting Markov processes, operating on novel speech/silence patterns, termed Steady Conversational Periods (SCPs). SCPs assume that whenever an agent's process changes state (e.g., from silence to speech), it causes a general transition of the entire conversational process, forcing inter-actant synchronization. SCPs fed into observed influence models, which captured the conversational dynamics of children and adolescents with Asperger syndrome/High Functioning Autism, and age-matched typically developing participants. Analyzing the parameters of the models by means of discriminative classifiers, the dialogs of patients were successfully distinguished from those of control participants. We conclude that meaning-free speech/silence sequences, reflecting inter-actant synchronization, at least partially encode typical and atypical conversational dynamics. This suggests a direct influence of theory of mind abilities onto basic speech initiative behavior.

  7. Automatic conversational scene analysis in children with Asperger syndrome/high-functioning autism and typically developing peers.

    Directory of Open Access Journals (Sweden)

    Alessandro Tavano

    Full Text Available Individuals with Asperger syndrome/High Functioning Autism fail to spontaneously attribute mental states to the self and others, a life-long phenotypic characteristic known as mindblindness. We hypothesized that mindblindness would affect the dynamics of conversational interaction. Using generative models, in particular Gaussian mixture models and observed influence models, conversations were coded as interacting Markov processes, operating on novel speech/silence patterns, termed Steady Conversational Periods (SCPs. SCPs assume that whenever an agent's process changes state (e.g., from silence to speech, it causes a general transition of the entire conversational process, forcing inter-actant synchronization. SCPs fed into observed influence models, which captured the conversational dynamics of children and adolescents with Asperger syndrome/High Functioning Autism, and age-matched typically developing participants. Analyzing the parameters of the models by means of discriminative classifiers, the dialogs of patients were successfully distinguished from those of control participants. We conclude that meaning-free speech/silence sequences, reflecting inter-actant synchronization, at least partially encode typical and atypical conversational dynamics. This suggests a direct influence of theory of mind abilities onto basic speech initiative behavior.

  8. A World at Risk: Aggregating Development Trends to Forecast Global Habitat Conversion

    Science.gov (United States)

    Oakleaf, James R.; Kennedy, Christina M.; Baruch-Mordo, Sharon; West, Paul C.; Gerber, James S.; Jarvis, Larissa; Kiesecker, Joseph

    2015-01-01

    A growing and more affluent human population is expected to increase the demand for resources and to accelerate habitat modification, but by how much and where remains unknown. Here we project and aggregate global spatial patterns of expected urban and agricultural expansion, conventional and unconventional oil and gas, coal, solar, wind, biofuels and mining development. Cumulatively, these threats place at risk 20% of the remaining global natural lands (19.68 million km2) and could result in half of the world’s biomes becoming >50% converted while doubling and tripling the extent of land converted in South America and Africa, respectively. Regionally, substantial shifts in land conversion could occur in Southern and Western South America, Central and Eastern Africa, and the Central Rocky Mountains of North America. With only 5% of the Earth’s at-risk natural lands under strict legal protection, estimating and proactively mitigating multi-sector development risk is critical for curtailing the further substantial loss of nature. PMID:26445282

  9. Conceptualisation and development of the Conversational Health Literacy Assessment Tool (CHAT).

    Science.gov (United States)

    O'Hara, Jonathan; Hawkins, Melanie; Batterham, Roy; Dodson, Sarity; Osborne, Richard H; Beauchamp, Alison

    2018-03-22

    The aim of this study was to develop a tool to support health workers' ability to identify patients' multidimensional health literacy strengths and challenges. The tool was intended to be suitable for administration in healthcare settings where health workers must identify health literacy priorities as the basis for person-centred care. Development was based on a qualitative co-design process that used the Health Literacy Questionnaire (HLQ) as a framework to generate questions. Health workers were recruited to participate in an online consultation, a workshop, and two rounds of pilot testing. Participating health workers identified and refined ten questions that target five areas of assessment: supportive professional relationships, supportive personal relationships, health information access and comprehension, current health behaviours, and health promotion barriers and support. Preliminary evidence suggests that application of the Conversational Health Literacy Assessment Tool (CHAT) can support health workers to better understand the health literacy challenges and supportive resources of their patients. As an integrated clinical process, the CHAT can supplement existing intake and assessment procedures across healthcare settings to give insight into patients' circumstances so that decisions about care can be tailored to be more appropriate and effective.

  10. A World at Risk: Aggregating Development Trends to Forecast Global Habitat Conversion.

    Directory of Open Access Journals (Sweden)

    James R Oakleaf

    Full Text Available A growing and more affluent human population is expected to increase the demand for resources and to accelerate habitat modification, but by how much and where remains unknown. Here we project and aggregate global spatial patterns of expected urban and agricultural expansion, conventional and unconventional oil and gas, coal, solar, wind, biofuels and mining development. Cumulatively, these threats place at risk 20% of the remaining global natural lands (19.68 million km2 and could result in half of the world's biomes becoming >50% converted while doubling and tripling the extent of land converted in South America and Africa, respectively. Regionally, substantial shifts in land conversion could occur in Southern and Western South America, Central and Eastern Africa, and the Central Rocky Mountains of North America. With only 5% of the Earth's at-risk natural lands under strict legal protection, estimating and proactively mitigating multi-sector development risk is critical for curtailing the further substantial loss of nature.

  11. FY 1998 annual summary report on International Clean Energy Network Using Hydrogen Conversion (WE-NET) system technology. Subtask 6. Development of cryogenic temperature materials technologies; 1998 nendo seika hokokusho. Suiso riyo kokusai clean energy system gijutsu (WE-NET) subtask 6 (teion zairyo gijutsu no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Summarized herein are the cryogenic temperature materials technologies for the International Clean Energy Network Using Hydrogen Conversion (WE-NET) project, developed in FY 1998. The R and D programs have been implemented continuously since 1994. For stainless steel, the base and TIG weld metals were evaluated for their material characteristics in liquid hydrogen. The items investigated included the influences of hydrogen charge, 20% of stretch working on the base metal, welding methods, and ?-ferrite content on the characteristics. Fatigue strength of the base metal was found to increases as temperature decreases, but remain unchanged in a range from 20 to 77K. No significant difference was observed between 304L and 316L. For aluminum alloy, mechanical characteristics, centered by fatigue characteristics, were investigated for the base and weld metals. The sample of higher tensile strength showed a higher fatigue strength, at room temperature, 77 and 4K. The other tested items investigated included embrittlement characteristics in a hydrogen atmosphere, phase transformation, hydrogen diffusion and fracture toughness, for establishing the databases of cryogenic temperature materials. (NEDO)

  12. A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

    Directory of Open Access Journals (Sweden)

    Naggar H. Saad

    2016-05-01

    Full Text Available The main challenges of wind energy conversion systems (WECS are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG current to extract the maximum power from the wind at a given wind velocity and to inject reactive power to the grid. Reactive power injection during the fault satisfying the grid-codes requirement. The proposed WECS has been modeled and simulated using PSCAD/EMTDC software package.

  13. Limitations of power conversion systems under transient loads and impact on the pulsed tokamak power reactor

    International Nuclear Information System (INIS)

    Sager, G.T.; Wong, C.P.C.; Kapich, D.D.; McDonald, C.F.; Schleicher, R.W.

    1993-11-01

    The impact of cyclic loading of the power conversion system of a helium-cooled, pulsed tokamak power plant is assessed. Design limits of key components of heat transport systems employing Rankie and Brayton thermodynamic cycles are quantified based on experience in gas-cooled fission reactor design and operation. Cyclic loads due to pulsed tokamak operation are estimated. Expected performance of the steam generator is shown to be incompatible with pulsed tokamak operation without load leveling thermal energy storage. The close cycle gas turbine is evaluated qualitatively based on performance of existing industrial and aeroderivative gas turbines. Advances in key technologies which significantly improve prospects for operation with tokamak fusion plants are reviewed

  14. Comparative study of energy conversion system dedicated to a small wind turbine

    International Nuclear Information System (INIS)

    Mirecki, A.

    2005-01-01

    This study presents a comparison of architectures and strategies of energy management dedicated to VAWT turbines such as Savonius. A Maximum Power Point Tracking must be implemented in order to optimize the energetic behavior. A torque or a speed control, or an indirect control of the DC bus current is possible. In the fact that the wind turbine characteristic is unknown, an operational research based on fuzzy logic is proposed. Aiming to minimize the cost of the static conversion structure, simple structures (diode bridge inverter, associated with DC-DC chopper) are analyzed and compared with a system based on a PWM Voltage Source Inverter. A test bench has been realized in the meantime as a system simulation. Comparisons of the provided energy are made for different wind speeds allowing to evaluate the performance of each structure and of the control strategies. (author)

  15. 5 CFR 9701.373 - Conversion of employees to the DHS pay system.

    Science.gov (United States)

    2010-01-01

    ... under § 9701.333). (b) When an employee receiving a special rate under 5 U.S.C. 5305 before conversion... locality or special rate supplement, the conversion will not be considered as resulting in a reduction in... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion of employees to the DHS pay...

  16. Robust fault detection of wind energy conversion systems based on dynamic neural networks.

    Science.gov (United States)

    Talebi, Nasser; Sadrnia, Mohammad Ali; Darabi, Ahmad

    2014-01-01

    Occurrence of faults in wind energy conversion systems (WECSs) is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS) is required. Recurrent neural networks (RNNs) have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate.

  17. International Clean Energy System Using Hydrogen Conversion (WE-NET). subtask 5. Development of hydrogen transport/storage technology (development of tanker for liquid hydrogen); Suiso riyo kokusai clean energy system gijutsu (WE-NET). subtask 5. Suiso yuso chozo gijutsu no kaihatsu (ekitai suiso yuso tanker no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    As a part of the WE-NET project, the tanker for liquid hydrogen transport was studied. In fiscal 1996, some experiments and numerical analyses were proposed which are necessary to solve technological issues extracted in fiscal 1995 for heat insulation structure. The issue was roughly classified into vacuum and non-vacuum insulation, and their basic functions and required performance were arranged. Boil-off rate of 0.2-0.4%/d was targeted. The insulation system which applies polyurethane form (PUF) to tank surfaces and injects atmospheric N2 gas into the surrounding hold space, could achieve the targeted insulation performance by PUF of 1m in thickness. The system of vacuum panel insulation and atmospheric N2 gas injection into a hold space required the panel of 500mm in thickness because of the large effect of metallic outer panel material. The system of vacuum hold and PUF panels was faced with the essential issue for realizing and maintaining vacuum hold. The super insulation system featured by layered insulation materials and vacuum layer spaces was also strongly affected by degree of vacuum. 23 figs., 8 tabs.

  18. Demonstrating Hybrid Heat Transport and Energy Conversion System Performance Characterization Using Intelligent Control Systems

    International Nuclear Information System (INIS)

    Ostrum, Lee; Manic, Milos

    2017-01-01

    The debate continues on the magnitude and validity of climate change caused by human activities. However, there is no debate about the need to make buildings, modes of transportation, factories, and homes as energy efficient as possible. Given that climate change could occur with the wasteful use of fossil fuel and the fact that fossil energy costs could and will swing wildly, it is imperative that every effort be made to utilize energy sources to their fullest. Hybrid energy systems (HES) are two or more separate energy producers used together to produce energy commodities. The HES this report focuses on is the use of nuclear reactor waste heat as a source of further energy utilization. Nuclear reactors use a fluid to cool the core and produce the steam needed for the production of electricity. Traditionally this steam, or coolant, is used to convert the energy then cooled elsewhere. The heat is released into the environment without being used further. By adding technologies to nuclear reactors to use the wasted heat, a system can be developed to make more than just electricity and allow for loading following capabilities.

  19. Demonstrating Hybrid Heat Transport and Energy Conversion System Performance Characterization Using Intelligent Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ostrum, Lee [Univ. of Idaho and Idaho Falls Center, Idaho Falls, ID (United States); Manic, Milos [Virginia Commonwealth Univ., Richmond, VA (United States)

    2017-09-28

    The debate continues on the magnitude and validity of climate change caused by human activities. However, there is no debate about the need to make buildings, modes of transportation, factories, and homes as energy efficient as possible. Given that climate change could occur with the wasteful use of fossil fuel and the fact that fossil energy costs could and will swing wildly, it is imperative that every effort be made to utilize energy sources to their fullest. Hybrid energy systems (HES) are two or more separate energy producers used together to produce energy commodities. The HES this report focuses on is the use of nuclear reactor waste heat as a source of further energy utilization. Nuclear reactors use a fluid to cool the core and produce the steam needed for the production of electricity. Traditionally this steam, or coolant, is used to convert the energy then cooled elsewhere. The heat is released into the environment without being used further. By adding technologies to nuclear reactors to use the wasted heat, a system can be developed to make more than just electricity and allow for loading following capabilities.

  20. Power Systems Development Facility

    International Nuclear Information System (INIS)

    1993-06-01

    The objective of the PSDF would be to provide a modular facility which would support the development of advanced, pilot-scale, coal-based power systems and hot gas clean-up components. These pilot-scale components would be designed to be large enough so that the results can be related and projected to commercial systems. The facility would use a modular approach to enhance the flexibility and capability for testing; consequently, overall capital and operating costs when compared with stand-alone facilities would be reduced by sharing resources common to different modules. The facility would identify and resolve technical barrier, as well as-provide a structure for long-term testing and performance assessment. It is also intended that the facility would evaluate the operational and performance characteristics of the advanced power systems with both bituminous and subbituminous coals. Five technology-based experimental modules are proposed for the PSDF: (1) an advanced gasifier module, (2) a fuel cell test module, (3) a PFBC module, (4) a combustion gas turbine module, and (5) a module comprised of five hot gas cleanup particulate control devices. The final module, the PCD, would capture coal-derived ash and particles from both the PFBC and advanced gasifier gas streams to provide for overall particulate emission control, as well as to protect the combustion turbine and the fuel cell

  1. Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-07-01

    This report discusses Test Campaign TC12 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (SW) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC12 began on May 16, 2003, with the startup of the main air compressor and the lighting of the gasifier start-up burner. The Transport Gasifier operated until May 24, 2003, when a scheduled outage occurred to allow maintenance crews to install the fuel cell test unit and modify the gas clean-up system. On June 18, 2003, the test run resumed when operations relit the start-up burner, and testing continued until the scheduled end of the run on July 14, 2003. TC12 had a total of 733 hours using Powder River Basin (PRB) subbituminous coal. Over the course of the entire test run, gasifier temperatures varied between 1,675 and 1,850 F at pressures from 130 to 210 psig.

  2. Advanced Dewatering Systems Development

    Energy Technology Data Exchange (ETDEWEB)

    R.H. Yoon; G.H. Luttrell

    2008-07-31

    A new fine coal dewatering technology has been developed and tested in the present work. The work was funded by the Solid Fuels and Feedstocks Grand Challenge PRDA. The objective of this program was to 'develop innovative technical approaches to ensure a continued supply of environmentally sound solid fuels for existing and future combustion systems with minimal incremental fuel cost.' Specifically, this solicitation is aimed at developing technologies that can (i) improve the efficiency or economics of the recovery of carbon when beneficiating fine coal from both current production and existing coal slurry impoundments and (ii) assist in the greater utilization of coal fines by improving the handling characteristics of fine coal via dewatering and/or reconstitution. The results of the test work conducted during Phase I of the current project demonstrated that the new dewatering technologies can substantially reduce the moisture from fine coal, while the test work conducted during Phase II successfully demonstrated the commercial viability of this technology. It is believed that availability of such efficient and affordable dewatering technology is essential to meeting the DOE's objectives.

  3. Advanced energy conversion and application - Decentralized energy systems. Papers; Fortschrittliche Energiewandlung und -anwendung - Schwerpunkt: Dezentrale Energiesysteme. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Decentralized energy systems is the major topic of this VDI report which contains the proceedings of the VDI conference on advanced energy conversion and application. The decentralized energy systems are in the focus because it is expected that they will gain in significance in the course of restructuring and liberalisation of the energy markets and growing commitment to greenhouse gas mitigation. The subjects of the papers are the cogeneration technology in general, and specific systems for combined generation of heat, power and cold,(CHPC systems), systems for renewable energy generation, industrial energy technology, and analysis and optimization of energy systems. The report is intended to serve as a source of guidance and reference for manufacturers and operators of decentralized energy systems, for decision-making on energy policy, and for the energy industry, counselling firms and regulatory/surveillance bodies, and members of universities involved in relevant research and development work. (orig./CB) [German] Themenschwerpunkt des VDI-Berichts sind die dezentralen Energiesysteme, die im Spannungsfeld von fortschreitender Liberalisierung der Energiemaerkte und der Bemuehungen um die Reduzierung von Emissionen an Bedeutung gewinnen. Dabei widmen sich die Beitraege den Systemen zur Kraft-Waerme-Kaelte-Kopplung und zur Nutzung erneuerbarer Energie sowie der industriellen Energietechnik und der Analyse und Optimierung von Energiesystemen. Der Bericht wendet sich an Hersteller und Betreiber dezentraler Energieanlagen, an Entscheidungstraeger aus Politik und Wirtschaft, an Berater und Ueberwachungsinstitutionen sowie an auf diesem Gebiet taetige Hochschullehrer und -mitarbeiter. (orig.)

  4. High-flux/high-temperature solar thermal conversion: technology development and advanced applications

    Directory of Open Access Journals (Sweden)

    Romero Manuel

    2016-01-01

    Full Text Available Solar Thermal Power Plants have generated in the last 10 years a dynamic market for renewable energy industry and a pro-active networking within R&D community worldwide. By end 2015, there are about 5 GW installed in the world, most of them still concentrated in only two countries, Spain and the US, though a rapid process of globalization is taking place in the last few years and now ambitious market deployment is starting in countries like South Africa, Chile, Saudi Arabia, India, United Arab Emirates or Morocco. Prices for electricity produced by today's plants fill the range from 12 to 16 c€/kWh and they are capital intensive with investments above 4000 €/kW, depending on the number of hours of thermal storage. The urgent need to speed up the learning curve, by moving forward to LCOE below 10 c€/kWh and the promotion of sun-to-fuel applications, is driving the R&D programmes. Both, industry and R&D community are accelerating the transformation by approaching high-flux/high-temperature technologies and promoting the integration with high-efficiency conversion systems.

  5. Development of methodology for assessment of absorbed dose and stopping power for low energy conversion electrons

    International Nuclear Information System (INIS)

    Almeida, Ivan Pedro Salati de

    1995-08-01

    The evaluation of absorbed dose in the case of external and internal contamination due to radionuclides is sometimes hard, because of the difficulties in the assessment of the absorbed dose caused by electrons with energy less than 100 KeV in mucous membrane. In this work, a methodology for assessment of absorbed dose and stopping power in VYNS (co-polymer of polivinyl chloride - acetate) absorbers, for the 62.5 KeV and 84-88 KeV energy 109 Cd conversion electrons, working with a 4 π proportional pressurized detector, is presented. In order to assure the reproducibility of measurement conditions, one of the detector halves has been used to obtain a spectrum of a thin 109 Cd source, without absorber. The other half of the detector was used in concomitance to obtain spectra with different thicknesses if absorber. The absorbed energy was obtained subtracting each spectrum with absorber from the spectrum without absorber, which were stored in a microcomputer connected to signal processing systems by ACE type interface. The VYNS weight and thickness were evaluated using common radionuclide metrology procedures. As VYNS has characteristics similar to a tissue equivalent material, the results obtained are consistent with dosimetric concepts and have a good agreement with those of the literature. (author)

  6. An approach for the development of visual configuration systems

    DEFF Research Database (Denmark)

    Hvam, Lars; Ladeby, Klaes Rohde

    2007-01-01

    How can a visual configuration system be developed to support the specification process' in companies that manufacture customer tailored products? This article focuses on how visual configuration systems can be developed. The approach for developing visual configuration systems has been developed...... by Centre for Product Modelling (CPM) at The Technical University of Denmark. The approach is based on experiences from a visualization project in co-operation between CPM and the global provider of power protection American Power Conversion (APC). The visual configuration system was developed in 2001...... of the product in the visual configuration system....

  7. Research and development in heavy and extra heavy oil upgrading in PDVSA-Intevep: aqua conversion

    International Nuclear Information System (INIS)

    Pereira, Pedro; Machin, Ivan; Salerno, Gladys; Cotte, Edgar; Higuerey, Ingrid; Andriollo, Antida; Cordova, Jose; Zacarias, Luis; Marzin, Roger; Rivas, Guaicaipuro

    1999-01-01

    After twenty five years of Intevep's creation, is now a good time to revise, from a technical and conceptual perspective, some of the ideas developed in one of the activities that this institution has more persistently sustained. The referred activity targets at the generation of new processes for the upgrading of the bitumen or extra heavy crude oils that Venezuela possesses. This revision concludes in an eclectic synthesis method for the selection and harmonization of the various different advances made through the research performed on processes such as HDH, coking, visbreaking, partial or selective steam reforming and others. Thus, from conceptually different research perspectives a new PDVSA's process already known as as aqua conversion has been assembled. The deepening in the use of this methodology may lead to other new and better upgrading technologies or to improve the existing for the same. All this keeping in mind that whatever these technologies are proprietary or from third parties is of low relevance in front of the mayor objective of commercializing the wide extra heavy oil reservoirs of this country

  8. A Retrospective Review of Thiazolidinediones with Development of a Troglitazone Conversion Protocol

    Directory of Open Access Journals (Sweden)

    Cameron Lindsey

    2003-01-01

    Full Text Available The objective of this paper was (1 to assess compliance with the National Veterans Affairs Guidelines for the use of troglitazone and rosiglitazone and (2 to develop and implement a conversion protocol that allows effective management of patients receiving troglitazone. A retrospective chart review was conducted to assess adherence to guidelines for all patients receiving troglitazone and rosiglitazone at the medical center. Appropriateness of therapy through indication evaluation, safety through alanine aminotransferase (ALT monitoring compliance, and efficacy through hemoglobin A1c (HbA1c changes were used to assess adherence. According to National Veterans Affairs (VA Guidelines, 68% of troglitazone and 63% of rosiglitazone patients had an appropriate indication for the use of these agents. Baseline ALT levels were obtained in 40% of troglitazone and 71% of rosiglitazone patients. Full compliance with continual ALT monitoring was seen in 6 and 54% of patients, respectively. Goal HbA1c was achieved in 57 and 29% of patients, respectively. Of the 33 patients receiving troglitazone, 19 were converted to rosiglitazone therapy; 11 were maintained on current regimens without troglitazone, and 3 were lost to follow up. Adherence to guidelines needs to be reinforced, in particular, compliance with ALT monitoring. However, there were no reported cases of hepatotoxicity in the patients reviewed. Many patients did not achieve a HbA1c

  9. CO2 injection into submarine, CH4-hydrate bearing sediments: Parameter studies towards the development of a hydrate conversion technology

    Science.gov (United States)

    Deusner, Christian; Bigalke, Nikolaus; Kossel, Elke; Haeckel, Matthias

    2013-04-01

    the reservoir is minimized. Our results clearly indicate that the formation of mixed CH4-CO2-hydrates is an important aspect in the conversion process. The experimental studies have shown that the injection of heated CO2 into the hydrate reservoir induces a variety of spatial and temporal processes which result in substantial bulk heterogeneity. Current numerical simulators are not able to predict these process dynamics and it is important to improve available transport-reaction models (e.g. to include the effect of bulk sediment permeability on the conversion dynamics). Our results confirm that experimental studies are important to better understand the mechanisms of hydrate dissociation and conversion at CO2-injection conditions as a basis towards the development of a suitable hydrate conversion technology. The application of non-invasive analytical methods such as Magnetic Resonance Imaging (MRI) and Raman microscopy are important tools, which were applied to resolve process dynamics on the pore scale. Additionally, the NESSI system is being modified to allow high-pressure flow-through experiments under triaxial loading to better simulate hydrate-sediment mechanics. This aspect is important for overall process development and evaluation of process safety issues.

  10. A reduced switch count UPF power conditioner for grid connected variable speed wind energy conversion system employing PM generators: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Raju, A.B.; Fernandes, B.G.; Chatterjee, K. [Indian Institute of Technology, Mumbai (India). Dept. of Electrical Engineering

    2004-07-01

    In this paper, modelling and simulation of a grid connected variable speed wind energy conversion system (VSWECS) with reduced switch count power converter is presented. The system consists of a permanent magnet synchronous generator (PMSG), two-pulse width modulated B-4 power converters and a maximum power point tracker (MPPT). Mathematical models of each element of the system are developed separately and are then integrated to simulate the whole system for various wind velocities. The complete system is simulated using MATLAB/SIMULINK and simulation results are presented. (author)

  11. IECEC '91; Proceedings of the 26th Intersociety Energy Conversion Engineering Conference, Boston, MA, Aug. 4-9, 1991. Vol. 5 - Renewable resource systems, Stirling engines and applications, systems and cycles

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Various papers on energy conversion engineering are presented. The general topics considered are: developments in nuclear power, energy from waste and biomass, system performance and materials in photovoltaics, solar thermal energy, wind energy systems, Stirling cycle analysis, Stirling cycle power, Stirling component technology, Stirling cooler/heat pump developments, Stirling engine concepts, Stirling engine design and optimization, Stirling engine dynamics and response, Stirling engine solar terrestrial, advanced cogeneration, AMTC, fossil fuel systems and technologies, marine energy

  12. Materials considerations for molten salt accelerator-based plutonium conversion systems

    International Nuclear Information System (INIS)

    DiStefano, J.R.; DeVan, J.H.; Keiser, J.R.; Klueh, R.L.; Eatherly, W.P.

    1995-03-01

    Accelerator-driven transmutation technology (ADTT) refers to a concept for a system that uses a blanket assembly driven by a source of neutrons produced when high-energy protons from an accelerator strike a heavy metal target. One application for such a system is called Accelerator-Based Plutonium Conversion, or ABC. Currently, the version of this concept being proposed by the Los Alamos National Laboratory features a liquid lead target material and a blanket fuel of molten fluorides that contain plutonium. Thus, the materials to be used in such a system must have, in addition to adequate mechanical strength, corrosion resistance to molten lead, corrosion resistance to molten fluoride salts, and resistance to radiation damage. In this report the corrosion properties of liquid lead and the LiF-BeF 2 molten salt system are reviewed in the context of candidate materials for the above application. Background information has been drawn from extensive past studies. The system operating temperature, type of protective environment, and oxidation potential of the salt are shown to be critical design considerations. Factors such as the generation of fission products and transmutation of salt components also significantly affect corrosion behavior, and procedures for inhibiting their effects are discussed. In view of the potential for extreme conditions relative to neutron fluxes and energies that can occur in an ADTT, a knowledge of radiation effects is a most important factor. Present information for potential materials selections is summarized

  13. Materials considerations for molten salt accelerator-based plutonium conversion systems

    International Nuclear Information System (INIS)

    DiStefano, J.R.; DeVan, J.H.; Keiser, J.R.; Klueh, R.L.; Eatherly, W.P.

    1995-02-01

    Accelerator-driven transmutation technology (ADTT) refers to a concept for a system that uses a blanket assembly driven by a source of neutrons produced when high-energy protons from an accelerator strike a heavy metal target. One application for such a system is called Accelerator-Based Plutonium Conversion, or ABC. Currently, the version of this concept being proposed by the Los Alamos National Laboratory features a liquid lead target material and a blanket fuel of molten fluorides that contain plutonium. Thus, the materials to be used in such a system must have, in addition to adequate mechanical strength, corrosion resistance to molten lead, corrosion resistance to molten fluoride salts, and resistance to radiation damage. In this report the corrosion properties of liquid lead and the LiF-BeF 2 molten salt system are reviewed in the context of candidate materials for the above application. Background information has been drawn from extensive past studies. The system operating temperature, type of protective environment, and oxidation potential of the salt are shown to be critical design considerations. Factors such as the generation of fission products and transmutation of salt components also significantly affect corrosion behavior, and procedures for inhibiting their effects are discussed. In view of the potential for extreme conditions relative to neutron fluxes and energies that can occur in an ADTT, a knowledge of radiation effects is a most important factor. Present information for potential materials selections is summarized

  14. Biocatalytic conversion of methane to methanol as a key step for development of methane-based biorefineries.

    Science.gov (United States)

    Hwang, In Yeub; Lee, Seung Hwan; Choi, Yoo Seong; Park, Si Jae; Na, Jeong Geol; Chang, In Seop; Kim, Choongik; Kim, Hyun Cheol; Kim, Yong Hwan; Lee, Jin Won; Lee, Eun Yeol

    2014-12-28

    Methane is considered as a next-generation carbon feedstock owing to the vast reserves of natural and shale gas. Methane can be converted to methanol by various methods, which in turn can be used as a starting chemical for the production of value-added chemicals using existing chemical conversion processes. Methane monooxygenase is the key enzyme that catalyzes the addition of oxygen to methane. Methanotrophic bacteria can transform methane to methanol by inhibiting methanol dehydrogenase. In this paper, we review the recent progress made on the biocatalytic conversion of methane to methanol as a key step for methane-based refinery systems and discuss future prospects for this technology.

  15. A Novel Maximum Power Point Tracking Control for Permanent Magnet Direct Drive Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2012-05-01

    Full Text Available This paper proposes a novel optimal current given (OCG maximum power point tracking (MPPT control strategy based on the theory of power feedback and hill climb searching (HCS for a permanent magnet direct drive wind energy conversion system (WECS. The presented strategy not only has the advantages of not needing the wind speed and wind turbine characteristics of the traditional HCS method, but it also improves the stability and accuracy of MPPT by estimating the exact loss torque. The OCG MPPT control strategy is first carried out by simulation, then an experimental platform based on the dSPACE1103 controller is built and a 5.5 kW permanent magnet synchronous generator (PMSG is tested. Furthermore, the proposed method is compared experimentally with the traditional optimum tip speed ratio (TSR MPPT control. The experiments verify the effectiveness of the proposed OCG MPPT strategy and demonstrate its better performance than the traditional TSR MPPT control.

  16. Study and experimental verification of control tuning strategies in a variable speed wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Zaragoza, Jordi; Pou, Josep; Arias, Antoni [Electronic Engineering Dept., Technical University of Catalonia, Campus Terrassa, C. Colom 1, 08222 Terrassa (Spain); Spiteri, Cyril [Department of Industrial Electrical Power Conversion, University of Malta, Faculty of Engineering, Msida (Malta); Robles, Eider; Ceballos, Salvador [Energy Unit, Robotiker-Tecnalia Technology Corporation, Zamudio, Basque Country (Spain)

    2011-05-15

    This paper analyzes and compares different control tuning strategies for a variable speed wind energy conversion system (WECS) based on a permanent-magnet synchronous generator (PMSG). The aerodynamics of the wind turbine (WT) and a PMSG have been modeled. The control strategy used in this research is composed of three regulators, which may be based on either linear or nonlinear controllers. In this analysis, proportional-integral (PI) linear controllers have been used. Two different tuning strategies are analyzed and compared. The main goal is to enhance the overall performance by achieving a low sensitivity to disturbances and minimal overshoot under variable operating conditions. Finally, the results have been verified by an experimental WECS laboratory prototype. (author)

  17. Clean energy systems in the subsurface. Production, storage and conversion. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Zhengmeng Michael; Were, Patrick (eds.) [Clausthal Univ. of Technology, Goslar (Germany). Energie-Forschungszentrum Niedersachsen (EFZN); Xie, Heping [Sichuan Univ., Chengdu (China)

    2013-04-01

    Recent research on Integrated Energy and Environmental Utilization of Deep Underground Space. Results of the 3{sup rd} Sino-German Conference ''Underground Storage of CO{sub 2} and Energy'', held at Goslar, Germany, 21-23 May 2013. Researchers and professionals from academia and industry discuss the future of deep underground space technologies for an integrated energy and environmental utilization. Anthropogenic greenhouse gas emissions, energy security and sustainability are three of the greatest contemporary global challenges today. This year the Sino-German Cooperation Group ''Underground Storage of CO{sub 2} and Energy'', is meeting on the 21-23 May 2013 for the second time in Goslar, Germany, to convene its 3{sup rd} Sino-German conference on the theme ''Clean Energy Systems in the Subsurface: Production, Storage and Conversion''.

  18. Recent progress in solution plasma-synthesized-carbon-supported catalysts for energy conversion systems

    Science.gov (United States)

    Lun Li, Oi; Lee, Hoonseung; Ishizaki, Takahiro

    2018-01-01

    Carbon-based materials have been widely utilized as the electrode materials in energy conversion and storage technologies, such as fuel cells and metal-air batteries. In these systems, the oxygen reduction reaction is an important step that determines the overall performance. A novel synthesis route, named the solution plasma process, has been recently utilized to synthesize various types of metal-based and heteroatom-doped carbon catalysts. In this review, we summarize cutting-edge technologies involving the synthesis and modeling of carbon-supported catalysts synthesized via solution plasma process, followed by current progress on the electrocatalytic performance of these catalysts. This review provides the fundamental and state-of-the-art performance of solution-plasma-synthesized electrode materials, as well as the remaining scientific and technological challenges for this process.

  19. Conversations with the community: the Methodist Hospital System's experience with social media.

    Science.gov (United States)

    Angelle, Denny; Rose, Clare L

    2011-01-01

    The Methodist Hospital System has maintained a social media presence on Facebook, Twitter, and YouTube since 2009. After initial unofficial excursions into the world of social media, we discovered that social media can be a useful tool to extend a conversation with our patients and the community at large and share our hospital's culture with a larger base of like-minded people. But with this new power comes a heightened responsibility--platforms that can potentially reach millions of viewers and readers also provide a potential for misuse that can jeopardize patient privacy and place hospitals at risk. Because of their unique restrictions, even hospitals that use the tools regularly have much left to learn about social media. With constant monitoring and stewardship and a commitment to educating staff, hospitals can effectively use social media tools for marketing and education.

  20. Financial problems facing the manufacturers of small wind energy conversion systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bolle, T G

    1979-11-01

    The financial barriers faced by the manufacturers of small wind energy conversion systems (SWECS) are assessed and found to be similar to those faced by other start up businesses. However, these problems are found to be aggravated by the high expectations for accelerated SWECS industry growth in the face of moderate government support and lack of investment capital. The underlying conditions of limited SWECS entrepreneur business experience, the highly competitive venture capital market, the inability of existing financial institutions to aid infant busineses and public unawareness of SWECS are reviewed. Specific manufacturer-oriented recommendations and federal, state and regulatory policy-oriented recommendations are made. In addition, the dynamics of the SWECS commercialization process are assessed and the variety of financial institutions playing a role in this process is detailed. Issues related to inflation, tax policy, regulation and federal R and D procurement policies are analyzed.

  1. Mathematical programming models for the economic design and assessment of wind energy conversion systems

    Science.gov (United States)

    Reinert, K. A.

    The use of linear decision rules (LDR) and chance constrained programming (CCP) to optimize the performance of wind energy conversion clusters coupled to storage systems is described. Storage is modelled by LDR and output by CCP. The linear allocation rule and linear release rule prescribe the size and optimize a storage facility with a bypass. Chance constraints are introduced to explicitly treat reliability in terms of an appropriate value from an inverse cumulative distribution function. Details of deterministic programming structure and a sample problem involving a 500 kW and a 1.5 MW WECS are provided, considering an installed cost of $1/kW. Four demand patterns and three levels of reliability are analyzed for optimizing the generator choice and the storage configuration for base load and peak operating conditions. Deficiencies in ability to predict reliability and to account for serial correlations are noted in the model, which is concluded useful for narrowing WECS design options.

  2. NLCC controller for SEPIC-based micro-wind energy conversion system

    Science.gov (United States)

    Justin Nayagam, Brintha Jane; Sathi, Rama Reddy; Olimuthu, Divya

    2017-04-01

    The growth of the power industry is gaining greater momentum as the usage of the non-conventional energy sources that include fuel, solar, and wind energies, increases. Wind energy conversion systems (WECSs) are gaining more popularity and are expected to be able to control the power at the output. This paper describes the current control (CC), non-linear carrier charge control (NLCCC), and fuzzy logic control (FLC) applied to the single-ended primary inductor converter (SEPIC)-based WECS. The current controller has an inherent overcurrent protection with better line noise rejection. The pulses for the switch of the SEPIC are obtained by comparing the current flowing through it with the virtual current reference. FLC is also investigated for the micro-wind energy conversion system (μWECS), since it improves the damping characteristics of WECS over a wide range of operating points. This cannot attain the unity power factor rectification. In this paper, NLCCC is proposed for high-power factor rectifier-based SEPIC in continuous conduction mode (CCM) for μWECS. The proposed converter provides an output voltage with low input current ripple due to the presence of the inductor at the input side. By comparing the signal proportional to the integral of switch current with a periodic non-linear carrier wave, the duty ratio of the converter switch is determined for the NLCC controller. By selecting the shape of the periodic non-linear carrier wave the input-line current can be made to follow the input-line voltage. This work employs a parabolic carrier waveform generator. The output voltage is regulated for changes in the wind speed. The results obtained prove the effectiveness of the NLCC controller in improving the power factor.

  3. Conversion of actinide solutions for the production of MA bearing fuels for Gen IV fast reactor systems

    International Nuclear Information System (INIS)

    Fernandez, A.; McGinley, J.; Somers, J.

    2008-01-01

    The conversion of the solution to solid for fuels containing minor actinides for accelerator driven systems or Gen IV fast reactors cannot be made by conventional ammonia or oxalate precipitation as is the case in today's reprocessing plant. The small particle size and concomitant dust that is produced in subsequent processing steps will not permit use of these processes on industrial scale. Innovation is needed to avoid dust generating powders, and indeed to simplify the processes themselves. Two such processing routes have been developed at the JRC-ITU. The sol gel route has been used to produce fuel containing Am and Np for the SUPERFACT, TRABANT and other irradiation experiments. The infiltration process has also been established and fuels have been produced for the FUTURIX and HELIOS experiments. (authors)

  4. Conversion of actinide solutions for the production of MA bearing fuels for Gen IV fast reactor systems

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.; McGinley, J.; Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements P.O.Box 2340, Karlsruhe, D-76125 (Germany)

    2008-07-01

    The conversion of the solution to solid for fuels containing minor actinides for accelerator driven systems or Gen IV fast reactors cannot be made by conventional ammonia or oxalate precipitation as is the case in today's reprocessing plant. The small particle size and concomitant dust that is produced in subsequent processing steps will not permit use of these processes on industrial scale. Innovation is needed to avoid dust generating powders, and indeed to simplify the processes themselves. Two such processing routes have been developed at the JRC-ITU. The sol gel route has been used to produce fuel containing Am and Np for the SUPERFACT, TRABANT and other irradiation experiments. The infiltration process has also been established and fuels have been produced for the FUTURIX and HELIOS experiments. (authors)

  5. Proceedings of the fourth biennial conference and workshop on wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Kottler, Jr., R. J. [ed.

    1980-06-01

    Separate abstracts are included for papers presented concerning research and development requirements and utility interface and institutional issues for small-scale systems; design requirements and research and development requirements for large-scale systems; economic and operational requirements of large-scale wind systems; wind characteristics and wind energy siting; international activities; wind energy applications in agriculture; federal commercialization and decentralization plans; and wind energy innovative systems.

  6. Economics of coal conversion processing. Advances in coal gasification: support research. Advances in coal gasification: process development and analysis

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The fall meeting of the American Chemical Society, Division of Fuel Chemistry, was held at Miami Beach, Florida, September 10-15, 1978. Papers involved the economics of coal conversion processing and advances in coal gasification, especially support research and process development and analysis. Fourteen papers have been entered individually into EDB and ERA; three papers had been entered previously from other sources. (LTN)

  7. The Socialization of Children's Memory: Linking Maternal Conversational Style to the Development of Children's Autobiographical and Deliberate Memory Skills

    Science.gov (United States)

    Langley, Hillary A.; Coffman, Jennifer L.; Ornstein, Peter A.

    2017-01-01

    Data from a large-scale, longitudinal research study with an ethnically and socioeconomically diverse sample were utilized to explore linkages between maternal elaborative conversational style and the development of children's autobiographical and deliberate memory. Assessments were made when the children were aged 3, 5, and 6 years old, and the…

  8. Advances in defining a closed brayton conversion system for future ARIANE 5 space nuclear power applications

    International Nuclear Information System (INIS)

    Tilliette, Z.P.

    1986-06-01

    The present European ARIANE space program will expand into the large ARIANE 5 launch vehicle from 1995. It is assumed that important associated missions would require the generation of 200 kWe or more in space during several years at the very beginning of the next century. It is the reason why, in 1983, the French C.N.E.S. (Centre National d'Etudes Spatiales) and C.E.A. (Commissariat a l'Energie Atomique) have initiated preliminary studies of a space nuclear power system. The currently selected conversion system is a closed Brayton cycle. Reasons for this choice are given: high efficiency of a dynamic system; monophasic, inert working fluid; extensive turbomachinery experience, etc... A key aspect of the project is the adaptation to the heat rejection conditions, namely to the radiator geometry which depends upon the dimensions of the ARIANE 5 spacecraft. In addition to usual concepts already studied for space applications, another cycle arrangement is being investigated which could offer satisfactory compromises among many considerations, increase the efficiency of the system and make it more attractive as far as the specific mass (kg/kWe), the specific radiator area (m 2 /kWe) and various technological aspects are concerned. Comparative details are presented

  9. Maximum power tracking in WECS (Wind energy conversion systems) via numerical and stochastic approaches

    International Nuclear Information System (INIS)

    Elnaggar, M.; Abdel Fattah, H.A.; Elshafei, A.L.

    2014-01-01

    This paper presents a complete design of a two-level control system to capture maximum power in wind energy conversion systems. The upper level of the proposed control system adopts a modified line search optimization algorithm to determine a setpoint for the wind turbine speed. The calculated speed setpoint corresponds to the maximum power point at given operating conditions. The speed setpoint is fed to a generalized predictive controller at the lower level of the control system. A different formulation, that treats the aerodynamic torque as a disturbance, is postulated to derive the control law. The objective is to accurately track the setpoint while keeping the control action free from unacceptably fast or frequent variations. Simulation results based on a realistic model of a 1.5 MW wind turbine confirm the superiority of the proposed control scheme to the conventional ones. - Highlights: • The structure of a MPPT (maximum power point tracking) scheme is presented. • The scheme is divided into the optimization algorithm and the tracking controller. • The optimization algorithm is based on an online line search numerical algorithm. • The tracking controller is treating the aerodynamics torque as a loop disturbance. • The control technique is simulated with stochastic wind speed by Simulink and FAST

  10. A Power Supply System with ZVS and Current-Doubler Features for Hybrid Renewable Energy Conversion

    Directory of Open Access Journals (Sweden)

    Jye-Chau Su

    2013-09-01

    Full Text Available In this paper, a power supply system for hybrid renewable energy conversion is proposed, which can process PV (photovoltaic power and wind-turbine energy simultaneously for step-down voltage and high current applications. It is a dual-input converter and mainly contains a PV energy source, a wind turbine energy source, a zero-voltage-switching (ZVS forward converter, and a current-doubler rectifier. The proposed power supply system has the following advantages: (1 PV-arrays and wind-energy sources can alternatively deliver power to the load during climate or season alteration; (2 maximum power point tracking (MPPT can be accomplished for both different kinds of renewable-energy sources; (3 ZVS and synchronous rectification techniques for the active switches of the forward converter are embedded so as to reduce switching and conducting losses; and (4 electricity isolation is naturally obtained. To achieve an optimally dynamic response and to increase control flexibility, a digital signal processor (DSP is investigated and presented to implement MPPT algorithm and power regulating scheme. Finally, a 240 W prototype power supply system with ZVS and current-doubler features to deal with PV power and wind energy is built and implemented. Experimental results are presented to verify the performance and the feasibility of the proposed power supply system.

  11. The Liquid Droplet Radiator - an Ultralightweight Heat Rejection System for Efficient Energy Conversion in Space

    Science.gov (United States)

    Mattick, A. T.; Hertzberg, A.

    1984-01-01

    A heat rejection system for space is described which uses a recirculating free stream of liquid droplets in place of a solid surface to radiate waste heat. By using sufficiently small droplets ( 100 micron diameter) of low vapor pressure liquids the radiating droplet sheet can be made many times lighter than the lightest solid surface radiators (heat pipes). The liquid droplet radiator (LDR) is less vulnerable to damage by micrometeoroids than solid surface radiators, and may be transported into space far more efficiently. Analyses are presented of LDR applications in thermal and photovoltaic energy conversion which indicate that fluid handling components (droplet generator, droplet collector, heat exchanger, and pump) may comprise most of the radiator system mass. Even the unoptimized models employed yield LDR system masses less than heat pipe radiator system masses, and significant improvement is expected using design approaches that incorporate fluid handling components more efficiently. Technical problems (e.g., spacecraft contamination and electrostatic deflection of droplets) unique to this method of heat rejectioon are discussed and solutions are suggested.

  12. Comparative study of energy conversion system dedicated to a small wind turbine; Etude comparative de chaines de conversion d'energie dediees a une eolienne de petite puissance

    Energy Technology Data Exchange (ETDEWEB)

    Mirecki, A

    2005-07-01

    This study presents a comparison of architectures and strategies of energy management dedicated to VAWT turbines such as Savonius. A Maximum Power Point Tracking must be implemented in order to optimize the energetic behavior. A torque or a speed control, or an indirect control of the DC bus current is possible. In the fact that the wind turbine characteristic is unknown, an operational research based on fuzzy logic is proposed. Aiming to minimize the cost of the static conversion structure, simple structures (diode bridge inverter, associated with DC-DC chopper) are analyzed and compared with a system based on a PWM Voltage Source Inverter. A test bench has been realized in the meantime as a system simulation. Comparisons of the provided energy are made for different wind speeds allowing to evaluate the performance of each structure and of the control strategies. (author)

  13. Development of a two-dimensional simulation code (koad) including atomic processes for beam direct energy conversion

    International Nuclear Information System (INIS)

    Yamamoto, Y.; Yoshikawa, K.; Hattori, Y.

    1987-01-01

    A two-dimensional simulation code for the beam direct energy conversion called KVAD (Kyoto University Advanced DART) including various loss mechanisms has been developed, and shown excellent agreement with the authors' experiments using the He + beams. The beam direct energy converter (BDC) is the device to recover the kinetic energy of unneutralized ions in the neutral beam injection (NBI) system directly into electricity. The BDC is very important and essential not only to the improvements of NBI system efficiency, but also to the relaxation of high heat flux problems on the beam dump with increase of injection energies. So far no simulation code could have successfully predicted BDC experimental results. The KUAD code applies, an optimized algorithm for vector processing, the finite element method (FEM) for potential calculation, and a semi-automatic method for spatial segmentations. Since particle trajectories in the KVAD code are analytically solved, very high speed tracings of the particle could be achieved by introducing an adjacent element matrix to identify the neighboring triangle elements and electrodes. Ion space charges are also analytically calculated by the Cloud in Cell (CIC) method, as well as electron space charges. Power losses due to atomic processes can be also evaluated in the KUAD code

  14. A General Mathematical Framework for Calculating Systems-Scale Efficiency of Energy Extraction and Conversion: Energy Return on Investment (EROI and Other Energy Return Ratios

    Directory of Open Access Journals (Sweden)

    Adam R. Brandt

    2011-08-01

    Full Text Available The efficiencies of energy extraction and conversion systems are typically expressed using energy return ratios (ERRs such as the net energy ratio (NER or energy return on investment (EROI. A lack of a general mathematical framework prevents inter-comparison of NER/EROI estimates between authors: methods used are not standardized, nor is there a framework for succinctly reporting results in a consistent fashion. In this paper we derive normalized mathematical forms of four ERRs for energy extraction and conversion pathways. A bottom-up (process model formulation is developed for an n-stage energy harvesting and conversion pathway with various system boundaries. Formations with the broadest system boundaries use insights from life cycle analysis to suggest a hybrid process model/economic input output based framework. These models include indirect energy consumption due to external energy inputs and embodied energy in materials. Illustrative example results are given for simple energy extraction and conversion pathways. Lastly, we discuss the limitations of this approach and the intersection of this methodology with “top-down” economic approaches.

  15. The maximization of the efficiency in the energy conversion in isolated photovoltaic systems; Tecnicas de maxima transferencia de potencia em sistemas fotovoltaicos isolados

    Energy Technology Data Exchange (ETDEWEB)

    Machado-Neto, L. V. B.; Cabral, C. V. T.; Diniz, A. S. A. C.; Cortizo, P. C.; Oliveira-Filho, D.

    2004-07-01

    The maximization of the efficiency in the energy conversion is essential into the developing of technical and economic sustainability of photovoltaic solar energy systems. In this paper is realized the study of a power maximization technique for photovoltaic generators. The power maximization technique explored in this paper is the Maximum Power Point Tracking (MPPT). There are different strategies being studied currently; this work consists of the development of an electronic converter prototype for MPPT, including the developing of the tracking algorithm implemented in a microcontroller. It is also realized a simulation of the system and a prototype was assembled and the first results are presented here. (Author)

  16. Design study on evaluation for power conversion system concepts in high temperature gas cooled reactor with gas turbine

    International Nuclear Information System (INIS)

    Minatsuki, Isao; Mizokami, Yorikata

    2007-01-01

    The design studies on High Temperature Gas Cooled Reactor with Gas Turbine (HTGR-GT) have been performed, which were mainly promoted by Japan Atomic Energy Agency (JAEA) and supported by fabricators in Japan. HTGR-GT plant feature is almost determined by selection of power conversion system concepts. Therefore, plant design philosophy is observed characteristically in selection of them. This paper describes the evaluation and analysis of the essential concepts of the HTGR-GT power conversion system through the investigations based on our experiences and engineering knowledge as a fabricator. As a result, the following concepts were evaluated that have advantages against other competitive one, such as the horizontal turbo machine rotor, the turbo machine in an individual vessel, the turbo machine with single shaft, the generator inside the power conversion vessel, and the power conversion system cycle with an intercooler. The results of the study can contribute as reference data when the concepts will be selected. Furthermore, we addressed reasonableness about the concept selection of the Gas Turbine High Temperature Reactor GTHTR300 power conversion system, which has been promoted by JAEA. As a conclusion, we recognized the GTHTR300 would be one of the most promising concepts for commercialization in near future. (author)

  17. Advanced medium-voltage bidirectional dc-dc conversion systems for future electric energy delivery and management systems

    Science.gov (United States)

    Fan, Haifeng

    2011-12-01

    The distributed renewable energy generation and utilization are constantly growing, and are expected to be integrated with the conventional grid. The growing pressure for innovative solutions will demand power electronics to take an even larger role in future electric energy delivery and management systems, since power electronics are required for the conversion and control of electric energy by most dispersed generation systems Furthermore, power electronics systems can provide additional intelligent energy management, grid stability and power quality capabilities. Medium-voltage isolated dc-dc converter will become one of the key interfaces for grid components with moderate power ratings. To address the demand of medium voltage (MV) and high power capability for future electric energy delivery and management systems, the power electronics community and industry have been reacting in two different ways: developing semiconductor technology or directly connecting devices in series/parallel to reach higher nominal voltages and currents while maintaining conventional converter topologies; and by developing new converter topologies with traditional semiconductor technology, known as multilevel converters or modular converters. The modular approach uses the well-known, mature, and cheaper power semiconductor devices by adopting new converter topologies. The main advantages of the modular approach include: significant improvement in reliability by introducing desired level of redundancy; standardization of components leading to reduction in manufacturing cost and time; power systems can be easily reconfigured to support varying input-output specifications; and possibly higher efficiency and power density of the overall system. Input-series output-parallel (ISOP) modular configuration is a good choice to realize MV to low voltage (LV) conversion for utility application. However, challenges still remain. First of all, for the high-frequency MV utility application, the low

  18. Solids throttling valves for coal conversion and utilization development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sine, G.C.

    1980-11-01

    A complete test system to test, evaluate, and develop control valves for slurry letdown service in coal liquefaction plants is needed. The site identified for the test system was the SRC II Pilot Plant located at Ft. Lewis, Washington. The US Department of Energy, Morgantown Energy Technology Center, requested a test system design that would enable testing of various configuration letdown valves that would be compatible with the existing facility and have minimum impact on Pilot Plant operations. Drawings and specifications for such a test system were prepared, coordinated with Ft. Lewis personnel, revised to reflect Ft. Lewis operating personnel comments, and approved for use by the Morgantown Energy Technology Center. These drawings and specifications will enable the test system to be built, installed, and integrated with the existing facility by a general contractor.

  19. Systemic Lupus Erythematosus and Sjögren's Syndrome Complicated by Conversion Disorder: a Case Report.

    Science.gov (United States)

    Nakamura, Misa; Tanaka, Seiji; Inoue, Tadashi; Maeda, Yasuto; Okumiya, Kiyohito; Esaki, Takuya; Shimomura, G O; Masunaga, Kenji; Nagamitsu, Shinichiro; Yamashita, Yushiro

    2018-05-21

    Conversion disorder (CD) is sometimes accompanied by motor and sensory impairments, such as muscle weakness, paralysis, sensory hypersensitivity, and sensory loss. Sjögren's syndrome (SS) complicates 5-10% of cases of systemic lupus erythematosus (SLE). Patients with SS or SLE present with various neurological symptoms and psychiatric manifestations. When neurological symptoms are present, it is important to distinguish whether the symptoms are caused by a neurological or a mental disorder because the former requires early intensive intervention, such as methylprednisolone pulse therapy (MPT), whereas psychotherapy or antidepressant drugs are recommended for mental disorders. We noticed SS- and SLE-like symptoms just after a diagnosis of idiopathic thrombocytopenic purpura in a 14-year-old girl. At approximately the same time, paralysis started in her lower limbs and subsequently spread to her upper limbs. An examination for neurological symptoms revealed no abnormalities. Because of the conversion reaction between her neurological symptoms and her disease state, CD was suspected as the etiology of her physical symptoms. Nevertheless, because of the progressive nature of the neurological symptoms, MPT was initiated with concurrent administration of intravenous immunoglobulin, but it failed to achieve a good outcome. The patient's symptoms eventually improved after she underwent psychotherapy treatment for a few months. Because early diagnosis of the cause of neurological symptoms accompanying SS and SLE is difficult, it may be necessary to combine the two lines of treatment in the early stages. However, when a mental disorder is suspected, psychotherapy should be started early to minimize the use of unnecessary neurological treatment.

  20. Conceptual design of free-piston Stirling conversion system for solar power units

    Science.gov (United States)

    Loktionov, Iu. V.

    A conversion system has been conceptually designed for solar power units of the dish-Stirling type. The main design objectives were to demonstrate the possibility of attaining such performance characteristics as low manufacturing and life cycle costs, high reliability, long life, high efficiency, power output stability, self-balance, automatic (or self-) start-up, and easy maintenance. The system design includes a heat transfer and utilization subsystem with a solar receiver, a free-piston engine, an electric power generation subsystem, and a control subsystem. The working fluid is helium. The structural material is stainless steel for hot elements, aluminum alloys and plastics for others. The electric generation subunit can be fabricated in three options: with an induction linear alternator, with a permanent magnet linear alternator, and with a serial rotated induction generator and a hydraulic drive subsystem. The heat transfer system is based on heat pipes or the reflux boiler principle. Several models of heat transfer units using a liquid metal (Na or Na-K) have been created and demonstrated.

  1. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    Science.gov (United States)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  2. A Condensed Introduction to the Doubly Fed Induction Generator Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Julius Mwaniki

    2017-01-01

    Full Text Available The increase in wind power penetration, at 456 GW as of June 2016, has resulted in more stringent grid codes which specify that the wind energy conversion systems (WECS must remain connected to the system during and after a grid fault and, furthermore, must offer grid support by providing reactive currents. The doubly fed induction generator (DFIG WECS is a well-proven technology, having been in use in wind power generation for many years and having a large world market share due to its many merits. Newer technologies such as the direct drive gearless permanent magnet synchronous generator have come up to challenge its market share, but the large number of installed machines ensures that it remains of interest in the wind industry. This paper presents a concise introduction of the DFIG WECS covering its construction, operation, merits, demerits, modelling, control types, levels and strategies, faults and their proposed solutions, and, finally, simulation. Qualities for the optimal control strategy are then proposed. The paper is intended to cover major issues related to the DFIG WECS that are a must for an overview of the system and hence serve as an introduction especially for new entrants into this area of study.

  3. Conversion and Validation of Distribution System Model from a QSTS-Based Tool to a Real-Time Dynamic Phasor Simulator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Chamana, Manohar; Prabakar, Kumaraguru; Palmintier, Bryan; Baggu, Murali M.

    2017-04-11

    A software process is developed to convert distribution network models from a quasi-static time-series tool (OpenDSS) to a real-time dynamic phasor simulator (ePHASORSIM). The description of this process in this paper would be helpful for researchers who intend to perform similar conversions. The converter could be utilized directly by users of real-time simulators who intend to perform software-in-the-loop or hardware-in-the-loop tests on large distribution test feeders for a range of use cases, including testing functions of advanced distribution management systems against a simulated distribution system. In the future, the developers intend to release the conversion tool as open source to enable use by others.

  4. Conversion and Validation of Distribution System Model from a QSTS-Based Tool to a Real-Time Dynamic Phasor Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Chamana, Manohar; Prabakar, Kumaraguru; Palmintier, Bryan; Baggu, Murali M.

    2017-05-11

    A software process is developed to convert distribution network models from a quasi-static time-series tool (OpenDSS) to a real-time dynamic phasor simulator (ePHASORSIM). The description of this process in this paper would be helpful for researchers who intend to perform similar conversions. The converter could be utilized directly by users of real-time simulators who intend to perform software-in-the-loop or hardware-in-the-loop tests on large distribution test feeders for a range of use cases, including testing functions of advanced distribution management systems against a simulated distribution system. In the future, the developers intend to release the conversion tool as open source to enable use by others.

  5. Overview of condition monitoring and operation control of electric power conversion systems in direct-drive wind turbines under faults

    Science.gov (United States)

    Huang, Shoudao; Wu, Xuan; Liu, Xiao; Gao, Jian; He, Yunze

    2017-09-01

    Electric power conversion system (EPCS), which consists of a generator and power converter, is one of the most important subsystems in a direct-drive wind turbine (DD-WT). However, this component accounts for the most failures (approximately 60% of the total number) in the entire DD-WT system according to statistical data. To improve the reliability of EPCSs and reduce the operation and maintenance cost of DD-WTs, numerous researchers have studied condition monitoring (CM) and fault diagnostics (FD). Numerous CM and FD techniques, which have respective advantages and disadvantages, have emerged. This paper provides an overview of the CM, FD, and operation control of EPCSs in DD-WTs under faults. After introducing the functional principle and structure of EPCS, this survey discusses the common failures in wind generators and power converters; briefly reviewed CM and FD methods and operation control of these generators and power converters under faults; and discussed the grid voltage faults related to EPCSs in DD-WTs. These theories and their related technical concepts are systematically discussed. Finally, predicted development trends are presented. The paper provides a valuable reference for developing service quality evaluation methods and fault operation control systems to achieve high-performance and high-intelligence DD-WTs.

  6. Conversational Agents in E-Learning

    Science.gov (United States)

    Kerry, Alice; Ellis, Richard; Bull, Susan

    This paper discusses the use of natural language or 'conversational' agents in e-learning environments. We describe and contrast the various applications of conversational agent technology represented in the e-learning literature, including tutors, learning companions, language practice and systems to encourage reflection. We offer two more detailed examples of conversational agents, one which provides learning support, and the other support for self-assessment. Issues and challenges for developers of conversational agent systems for e-learning are identified and discussed.

  7. 5 CFR 9901.372 - Conversion or movement out of NSPS pay system.

    Science.gov (United States)

    2010-01-01

    ... worksite, and pay as of the day immediately before the date of conversion or movement out of NSPS. An... employee's pay band. If the employee's adjusted salary equals or exceeds the step 4 rate of the second... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion or movement out of NSPS pay...

  8. Experimental enhancement of fuzzy fractional order PI+I controller of grid connected variable speed wind energy conversion system

    International Nuclear Information System (INIS)

    Beddar, Antar; Bouzekri, Hacene; Babes, Badreddine; Afghoul, Hamza

    2016-01-01

    Highlights: • Fuzzy fractional order PI+I for wind energy conversion system is developed. • Investigation of the control methods performances under wind and load variations. • PSO algorithm with frequency method are used for parameters tuning. • Experimental results are presented. - Abstract: In this paper, fuzzy fractional order PI+I (FFOPI+I) controller for grid connected Variable Speed Wind Energy Conversion System (VS-WECS) is proposed. The FFOPI+I controller is applied to control a Permanent Magnet Synchronous Generator (PMSG) connected to the grid and nonlinear load through a back-to-back AC-DC-AC PWM converter. The control strategy of the Machine Side Converter (MSC) aims, at first, to extract a maximum power under fluctuating wind speed. Then, the Grid Side Converter (GSC) is controlled to improve the power quality and ensure sinusoidal current in the grid side. The FFOPI+I controller implements a Fuzzy Logic Controller (FLC) in parallel with Fractional Order PI (FOPI) and conventional PI controllers by having a commune proportional gain. The FLC changes the integral gains at runtime. The initial parameters of the FFOPI+I controller were calculated using a frequency method to create a search space then the PSO algorithm is used to select the optimal parameters. To evaluate the performance of the proposed controller in steady and transient states, an experimental test bench has been built in laboratory using dSPACE1104 card. The experimental results demonstrate the effectiveness and feasibility of the FFOPI+I over FOPI and conventional PI controllers by realizing maximum power extraction and improving the grid-side power factor for a wide range of wind speed.

  9. Development of a fermentation-based process for biomass conversion to hydrogen gas

    NARCIS (Netherlands)

    Claassen, P.A.M.; Vrije, de G.J.; Urbaniec, K.; Grabarczyk, R.

    2010-01-01

    The production of hydrogen gas from biomass to meet the foreseen demand arising from the expected introduction of fuel cells is envisaged. Apart from the well-known gasification method, fermentative conversion can also be applied for this purpose. Two options of the latter method, that is,

  10. The Development and Evolution of Person-Centered Expressive Art Therapy: A Conversation with Natalie Rogers

    Science.gov (United States)

    Sommers-Flanagan, John

    2007-01-01

    Many counselors are unaware that Natalie Rogers, daughter of Carl Rogers, has extended her father's work into the creative and expressive arts. This article includes a verbatim conversation with Natalie Rogers as she reflects on her childhood and her professional work. Person-centered expressive art therapy is an alternative to traditional verbal…

  11. Control Strategies for Smoothing of Output Power of Wind Energy Conversion Systems

    Science.gov (United States)

    Pratap, Alok; Urasaki, Naomitsu; Senju, Tomonobu

    2013-10-01

    This article presents a control method for output power smoothing of a wind energy conversion system (WECS) with a permanent magnet synchronous generator (PMSG) using the inertia of wind turbine and the pitch control. The WECS used in this article adopts an AC-DC-AC converter system. The generator-side converter controls the torque of the PMSG, while the grid-side inverter controls the DC-link and grid voltages. For the generator-side converter, the torque command is determined by using the fuzzy logic. The inputs of the fuzzy logic are the operating point of the rotational speed of the PMSG and the difference between the wind turbine torque and the generator torque. By means of the proposed method, the generator torque is smoothed, and the kinetic energy stored by the inertia of the wind turbine can be utilized to smooth the output power fluctuations of the PMSG. In addition, the wind turbines shaft stress is mitigated compared to a conventional maximum power point tracking control. Effectiveness of the proposed method is verified by the numerical simulations.

  12. A multi-agent conversational system with heterogeneous data sources access

    KAUST Repository

    Eisman, Eduardo M.

    2016-01-28

    In many of the problems that can be found nowadays, information is scattered across different heterogeneous data sources. Most of the natural language interfaces just focus on a very specific part of the problem (e.g. an interface to a relational database, or an interface to an ontology). However, from the point of view of users, it does not matter where the information is stored, they just want to get the knowledge in an integrated, transparent, efficient, effective, and pleasant way. To solve this problem, this article proposes a generic multi-agent conversational architecture that follows the divide and conquer philosophy and considers two different types of agents. Expert agents are specialized in accessing different knowledge sources, and decision agents coordinate them to provide a coherent final answer to the user. This architecture has been used to design and implement SmartSeller, a specific system which includes a Virtual Assistant to answer general questions and a Bookseller to query a book database. A deep analysis regarding other relevant systems has demonstrated that our proposal provides several improvements at some key features presented along the paper.

  13. Ecological and socio-economic functions across tropical land use systems after rainforest conversion.

    Science.gov (United States)

    Drescher, Jochen; Rembold, Katja; Allen, Kara; Beckschäfer, Philip; Buchori, Damayanti; Clough, Yann; Faust, Heiko; Fauzi, Anas M; Gunawan, Dodo; Hertel, Dietrich; Irawan, Bambang; Jaya, I Nengah S; Klarner, Bernhard; Kleinn, Christoph; Knohl, Alexander; Kotowska, Martyna M; Krashevska, Valentyna; Krishna, Vijesh; Leuschner, Christoph; Lorenz, Wolfram; Meijide, Ana; Melati, Dian; Nomura, Miki; Pérez-Cruzado, César; Qaim, Matin; Siregar, Iskandar Z; Steinebach, Stefanie; Tjoa, Aiyen; Tscharntke, Teja; Wick, Barbara; Wiegand, Kerstin; Kreft, Holger; Scheu, Stefan

    2016-05-19

    Tropical lowland rainforests are increasingly threatened by the expansion of agriculture and the extraction of natural resources. In Jambi Province, Indonesia, the interdisciplinary EFForTS project focuses on the ecological and socio-economic dimensions of rainforest conversion to jungle rubber agroforests and monoculture plantations of rubber and oil palm. Our data confirm that rainforest transformation and land use intensification lead to substantial losses in biodiversity and related ecosystem functions, such as decreased above- and below-ground carbon stocks. Owing to rapid step-wise transformation from forests to agroforests to monoculture plantations and renewal of each plantation type every few decades, the converted land use systems are continuously dynamic, thus hampering the adaptation of animal and plant communities. On the other hand, agricultural rainforest transformation systems provide increased income and access to education, especially for migrant smallholders. Jungle rubber and rubber monocultures are associated with higher financial land productivity but lower financial labour productivity compared to oil palm, which influences crop choice: smallholders that are labour-scarce would prefer oil palm while land-scarce smallholders would prefer rubber. Collecting long-term data in an interdisciplinary context enables us to provide decision-makers and stakeholders with scientific insights to facilitate the reconciliation between economic interests and ecological sustainability in tropical agricultural landscapes. © 2016 The Authors.

  14. A Concise Presentation of Doubly Fed Induction Generator Wind Energy Conversion Systems Challenges and Solutions

    Directory of Open Access Journals (Sweden)

    Julius Mwaniki

    2017-01-01

    Full Text Available There is increased worldwide wind power generation, a large percentage of which is grid connected. The doubly fed induction generator (DFIG wind energy conversion system (WECS has many merits and, as a result, large numbers have been installed to date. The DFIG WECS operation, under both steady state and fault conditions, is of great interest since it impacts on grid performance. This review paper presents a condensed look at the various applied solutions to the challenges of the DFIG WECS including maximum power point tracking, common mode voltages, subsynchronous resonance, losses, modulation, power quality, and faults both internal and from the grid. It also looks at approaches used to meet the increasingly stringent grid codes requirements for the DFIG WECS to not only ride through faults but also provide voltage support. These are aspects of the DFIG WECS that are critical for system operators and prospective investors and can also serve as an introduction for new entrants into this area of study.

  15. A multi-agent conversational system with heterogeneous data sources access

    KAUST Repository

    Eisman, Eduardo M.; Navarro, Marí a; Castro, Juan Luis

    2016-01-01

    In many of the problems that can be found nowadays, information is scattered across different heterogeneous data sources. Most of the natural language interfaces just focus on a very specific part of the problem (e.g. an interface to a relational database, or an interface to an ontology). However, from the point of view of users, it does not matter where the information is stored, they just want to get the knowledge in an integrated, transparent, efficient, effective, and pleasant way. To solve this problem, this article proposes a generic multi-agent conversational architecture that follows the divide and conquer philosophy and considers two different types of agents. Expert agents are specialized in accessing different knowledge sources, and decision agents coordinate them to provide a coherent final answer to the user. This architecture has been used to design and implement SmartSeller, a specific system which includes a Virtual Assistant to answer general questions and a Bookseller to query a book database. A deep analysis regarding other relevant systems has demonstrated that our proposal provides several improvements at some key features presented along the paper.

  16. Power management of a wind energy conversion system equipped by DFIG

    Directory of Open Access Journals (Sweden)

    Iman Zangiabadi

    2016-06-01

    Full Text Available Today wind is one of the attractive points of energy area which has got the noticeable amount of investment and studies in this field. Considering the importance of the wind energy and its potentials as one of the renewable energy sources, in this paper managing the production of active and reactive powers of a wind energy conversion system equipped with DFIG has been studied. In this regard, a structure based on vector control is offered to achieve an independent control of active and reactive powers. The strategy of managing the production of active and reactive power is applied to network by rotor side converter of a DFIG. The production of active power according to the maximum power point taking (MPPT strategy to get a maximum power of the wind energy has been done and also improvement of power quality based on strategies of power factor correction and harmonics reduction have been arranged for a power network. In order to evaluate the performance of the proposed method, a DFIG connected with a power network in different conditions of the reactive load has been simulated by MATLAB software.Obviously, the results state the proper operation of the power control of wind energy converting system , improvement of the network power factor, and Reduction of harmonic current of network based on the proposed method.

  17. Modeling the impact of large-scale energy conversion systems on global climate

    International Nuclear Information System (INIS)

    Williams, J.

    There are three energy options which could satisfy a projected energy requirement of about 30 TW and these are the solar, nuclear and (to a lesser extent) coal options. Climate models can be used to assess the impact of large scale deployment of these options. The impact of waste heat has been assessed using energy balance models and general circulation models (GCMs). Results suggest that the impacts are significant when the heat imput is very high and studies of more realistic scenarios are required. Energy balance models, radiative-convective models and a GCM have been used to study the impact of doubling the atmospheric CO 2 concentration. State-of-the-art models estimate a surface temperature increase of 1.5-3.0 0 C with large amplification near the poles, but much uncertainty remains. Very few model studies have been made of the impact of particles on global climate, more information on the characteristics of particle input are required. The impact of large-scale deployment of solar energy conversion systems has received little attention but model studies suggest that large scale changes in surface characteristics associated with such systems (surface heat balance, roughness and hydrological characteristics and ocean surface temperature) could have significant global climatic effects. (Auth.)

  18. Conversion of Indigenous Agricultural Waste Feedstocks to Fuel Ethanol. Cooperative Research and Development Final Report, CRADA Number CRD-13-504

    Energy Technology Data Exchange (ETDEWEB)

    Elander, Richard [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-27

    This Cooperative Research and Development Agreement (CRADA) is between the National Renewable Energy Laboratory (NREL), a world leader in biomass conversion research and Ecopetrol American Inc., Ecopetrol S.A.'s U.S. subsidiary. The research and development efforts described in the Joint Work Statement (JWS) will take advantage of the strengths of both parties. NREL will use its Integrated Biorefinery Facility and vast experience in the conversion of lignocellulosic feedstocks to fuel ethanol to develop processes for the conversion of Ecopetrol's feedstocks. Ecopetrol will establish the infrastructure in Columbia to commercialize the conversion process.

  19. Stabilization of Wind Energy Conversion System with Hydrogen Generator by Using EDLC Energy Storage System

    Science.gov (United States)

    Shishido, Seiji; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji; Sugimasa, Masatoshi; Komura, Akiyoshi; Futami, Motoo; Ichinose, Masaya; Ide, Kazumasa

    The spread of wind power generation is progressed hugely in recent years from a viewpoint of environmental problems including global warming. Though wind power is considered as a very prospective energy source, wind power fluctuation due to the random fluctuation of wind speed has still created some problems. Therefore, research has been performed how to smooth the wind power fluctuation. This paper proposes Energy Capacitor System (ECS) for the smoothing of wind power which consists of Electric Double-Layer Capacitor (EDLC) and power electronics devices and works as an electric power storage system. Moreover, hydrogen has received much attention in recent years from a viewpoint of exhaustion problem of fossil fuel. Therefore it is also proposed that a hydrogen generator is installed at the wind farm to generate hydrogen. In this paper, the effectiveness of the proposed system is verified by the simulation analyses using PSCAD/EMTDC.

  20. Recent progress in the development of solid catalysts for biomass conversion into high value-added chemicals

    Science.gov (United States)

    Hara, Michikazu; Nakajima, Kiyotaka; Kamata, Keigo

    2015-06-01

    In recent decades, the substitution of non-renewable fossil resources by renewable biomass as a sustainable feedstock has been extensively investigated for the manufacture of high value-added products such as biofuels, commodity chemicals, and new bio-based materials such as bioplastics. Numerous solid catalyst systems for the effective conversion of biomass feedstocks into value-added chemicals and fuels have been developed. Solid catalysts are classified into four main groups with respect to their structures and substrate activation properties: (a) micro- and mesoporous materials, (b) metal oxides, (c) supported metal catalysts, and (d) sulfonated polymers. This review article focuses on the activation of substrates and/or reagents on the basis of groups (a)-(d), and the corresponding reaction mechanisms. In addition, recent progress in chemocatalytic processes for the production of five industrially important products (5-hydroxymethylfurfural, lactic acid, glyceraldehyde, 1,3-dihydroxyacetone, and furan-2,5-dicarboxylic acid) as bio-based plastic monomers and their intermediates is comprehensively summarized.