Science.gov

Sample records for high performance mcfc

  1. High performance MCFC using Li/Na electrolyte

    SciTech Connect

    Donado, R.A.; Ong, E.T.; Sishtla, C.I.

    1995-08-01

    The substitution of a lithium/ sodium carbonate (Li/Na) mixture for the lithium/potassium carbonate (Li/K) electrolyte used in MCFCs holds the promise of higher ionic conductivity, higher exchange current density at both electrodes, lower vapor pressure, and lower cathode dissolution rates. However, when the substitution is made in cells optimized for use with the Li/K electrolyte, the promised increase in performance is not realized. As a consequence the literature contains conflicting data with regard to the performance, compositional stability, and chemical reactivity of the Li/Na electrolyte. Experiments conducted at the Institute of Gas Technology (IGT) concluded that the source of the problem is the different wetting characteristics of the two electrolytes. Electrode pore structures optimized for use with Li/K do not work well with Li/Na. Using proprietary methods and materials, IGT was able to optimize a set of electrodes for the Li/Na electrolyte. Experiments conducted in bench-scale cells have confirmed the superior performance of the Li/Na electrolyte compared to the Li/K electrolyte. The Li/Na cells exhibited a 5 to 8 percent improvement in overall performance, a substantial decrease in the rate of cathode dissolution, and a decreased decay rate. The longest running cell has logged over 13,000 hours of operation with a decay rate of less than 2 mV/1000 hours.

  2. High temperature corrosion of separator materials for MCFC

    SciTech Connect

    Yanagida, Masahiro; Tanimoto, Kazumi; Kojima, Toshikatsu

    1996-12-31

    The Molten Carbonate Fuel Cell (MCFC) is one of promising high efficiency power generation devices with low emission. Molten carbonate used for its electrolyte plays an important role in MCFC. It separates between anode and cathode gas environment and provides ionic conductivity on MCFC operation. Stainless steel is conventionally used as separator/current collector materials in MCFC cathode environment. As corrosion of the components of MCFC caused by the electrolyte proceeds with the electrolyte consumption, the corrosion in the MCFC is related to its performance and life. To understand and inhibit the corrosion in the MCFC is important to realize MCFC power generation system. We have studied the effect of alkaline earth carbonate addition into carbonate on corrosion of type 316L stainless steel. In this paper, we describe the effect of the temperature on corrosion behavior of type 316L stainless steel with carbonate mixture, (Li{sub 0.62}K{sub 0.38}){sub 2}CO{sub 3}, under the cathode environment in out-of-cell test.

  3. High performance electrolytes for MCFC

    DOEpatents

    Kaun, T.D.; Roche, M.F.

    1999-08-24

    A carbonate electrolyte of the Li/Na or CaBaLiNa system is described. The Li/Na carbonate has a composition displaced from the eutectic composition to diminish segregation effects in a molten carbonate fuel cell. The CaBaLiNa system includes relatively small amounts of Ca{sub 2}CO{sub 3} and BaCO{sub 3}, and preferably of equimolar amounts. The presence of both Ca and BaCO{sub 3} enables lower temperature fuel cell operation. 15 figs.

  4. High performance electrolytes for MCFC

    DOEpatents

    Kaun, Thomas D.; Roche, Michael F.

    1999-01-01

    A carbonate electrolyte of the Li/Na or CaBaLiNa system. The Li/Na carbonate has a composition displaced from the eutectic composition to diminish segregation effects in a molten carbonate fuel cell. The CaBaLiNa system includes relatively small amounts of Ca.sub.2 CO.sub.3 and BaCO.sub.3, and preferably of equimolar amounts. The presence of both Ca and BaCO.sub.3 enables lower temperature fuel cell operation.

  5. MCFC component development at ANL.

    SciTech Connect

    Bloom, I.

    1998-09-15

    Argonne National Laboratory is developing advanced cathode and electrolyte components for the molten carbonate fuel cell (MCFC). Working in support of the MCFC developers, the goal of this effort is to extend the life of the MCFC cell and to improve its performance.

  6. Technology base studies of long-term MCFC performance

    SciTech Connect

    Selman, J.R.

    1995-08-01

    Cathode dissolution into the electrolyte matrix and endurance of current collector/separator plate materials are the main life-limiting factors of the state-of-the art MCFC. These components are also major contributors to the total system cost. Therefore, to reduce capital cost, it is necessary to minimize hardware corrosion and increase cell life. This study consists of experimental evaluation of corrosion processes with the objective to further practical; understanding of corrosion behavior of alloys and alloy components under cathodic gas conditions. Nickel, iron, cobalt and stainless steels 310 and 316L are analyzed. The experimental study consists of (1) Observation of open circuit potential (OCP) changes. Surface reactions occurring without net passage of current are proposed based on this measurement. (2) Applying cyclic voltammetry, which provides information about the possible electrode reactions at different stages of polarization. (3) Applying AC impedance to support the result of tasks 1 and 2 at different stages of oxidation, and data analysis by means of equivalent circuits. Open circuit conditions as well as positive and negative polarization are used in the impedance measurements. (4) Surface analysis of the electrodes by SEM-EDX and X-ray diffraction. To obtain more information from electrochemical measurements a novel approach has been applied in cell design. In this two-electrode approach, one electrode is fully immersed, and the other is wetted by carbonate melt via an alumina tube which has a thin film on it. While camera observation of these two different electrode conditions will identify the effect of carbonate wetting on the state of the surface, electrochemical measurements enable a quantitative comparison between complete submersion and wetting by a film of carbonate.

  7. Performance of new 10 kW class MCFC using Li/K and Li/Na electrolyte

    SciTech Connect

    Mugikura, Yoshihiro; Yoshiba, Fumihiko; Izaki, Yoshiyuki; Watanabe, Takao

    1996-12-31

    The molten carbonate fuel cell (MCFC) uses generally mixture of lithium carbonate and potassium carbonate (Li/K) as the electrolyte. NiO cathode dissolution is one of serious problems for MCFC life. The NiO cathode has been found to dissolve into the electrolyte as Ni{sup 2+} ion which is reduced to metallic Ni by H{sub 2} in the fuel gas and bridges the anode and the cathode. The bridges short circuit and degrade cell performance and shorten cell life. Since solubility of NiO in mixture of lithium carbonate and sodium carbonate (Li/Na) is lower than in Li/K, it takes longer time to take place slowing by NiO cathode dissolution in Li/Na compared with in Li/K. The ionic conductivity of Li/Na is higher than of Li/K, however, oxygen solubility in Li/Na is lower 9 than in Li/K. A new 10 kW class MCFC stack composed of Li/K cells and Li/Na cells, was tested. Basic performance of the Li/K cells and Li/Na cells of the stack was reported.

  8. Prediction of temperature profile in MCFC stack

    SciTech Connect

    Lee, Kab Soo; Kim, Hwayong; Hong, Seong-An; Lim, Hee Chun

    1996-12-31

    A simple three dimensional model was developed to simulate the temperature distribution and the performance of various flow types of the MCFC stack. The objective of this study was to understand the complicated phenomena occurring in the MCFC stack and to supply the basic data for optimizing the operating condition of the MCFC stack. Assuming that the stack consists of a number of differential elements which have uniform temperature and gas composition, the model was solved by finite difference method. The performance of this model was demonstrated by comparing the calculated value with experimental data of the 1.5kW class co-flow type MCFC stack operated in KIST. This model can be utilized as a simple diagnostic tool in case of the operational abnormality such as the hot spot which often occurs inside the stack.

  9. MCFC and microturbine power plant simulation

    NASA Astrophysics Data System (ADS)

    Orecchini, F.; Bocci, E.; Di Carlo, A.

    The consistent problem of the CO 2 emissions and the necessity to find new energy sources, are motivating the scientific research to use high efficiency electric energy production's technologies that could exploit renewable energy sources too. The molten carbonate fuel cell (MCFC) due to its high efficiencies and low emissions seems a valid alternative to the traditional plant. Moreover, the high operating temperature and pressure give the possibility to use a turbine at the bottom of the cells to produce further energy, increasing therefore the plant's efficiencies. The basic idea using this two kind of technologies (MCFC and microturbine), is to recover, via the microturbine, the necessary power for the compressor, that otherwise would remove a consistent part of the MCFC power generated. The purpose of this work is to develop the necessary models to analyze different plant configurations. In particular, it was studied a plant composed of a MCFC 500 kW Ansaldo at the top of a microturbine 100 kW Turbec. To study this plant it was necessary to develop: (i) MCFC mathematical model, that starting from the geometrical and thermofluidodynamic parameter of the cell, analyze the electrochemical reaction and shift reaction that take part in it; (ii) plate reformer model, a particular compact reformer that exploit the heat obtained by a catalytic combustion of the anode and part of cathode exhausts to reform methane and steam; and (iii) microturbine-compressor model that describe the efficiency and pressure ratio of the two machines as a function of the mass flow and rotational regime. The models developed was developed in Fortran language and interfaced in Chemcad © to analyze the power plant thermodynamic behavior. The results show a possible plant configuration with high electrical and global efficiency (over 50 and 74%).

  10. Status of MCFC stack technology at IHI

    SciTech Connect

    Hosaka, M.; Morita, T.; Matsuyama, T.; Otsubo, M.

    1996-12-31

    The molten carbonate fuel cell (MCFC) is a promising option for highly efficient power generation possible to enlarge. IHI has been studying parallel flow MCFC stacks with internal manifolds that have a large electrode area of 1m{sup 2}. IHI will make two 250 kW stacks for MW plant, and has begun to make cell components for the plant. To improve the stability of stack, soft corrugated plate used in the separator has been developed, and a way of gathering current from stacks has been studied. The DC output potential of the plant being very high, the design of electric insulation will be very important. A 20 kW short stack test was conducted in 1995 FY to certificate some of the improvements and components of the MW plant. These activities are presented below.

  11. Studies of biomass fuelled MCFC systems

    NASA Astrophysics Data System (ADS)

    Kivisaari, Timo; Björnbom, Pehr; Sylwan, Christopher

    In the present work, the methods, techniques and results obtained during the studies of biomass fuelled molten carbonate fuel cell (MCFC) systems within the Swedish national fuel cell program are presented. The power plants are 60 MW class, utilising biomass (i.e. wood chips) as the primary fuel. The biomass is converted via pressurised gasification into a gaseous form that, after subsequent cleaning, can be used in the fuel cells. An investigation of the effects of gasification pressure, temperature and the influence of internal reforming on the overall system performance is presented. All studies were carried out using the Aspen Plus™ with Model Manager™ simulation package.

  12. The `advanced DIR-MCFC development' project, an overview

    NASA Astrophysics Data System (ADS)

    Kortbeek, P. J.; Ottervanger, R.

    An overview is given of the approach and mid-term status of the joint European `Advanced DIR-MCFC Development' project, in which BCN, BG plc, GDF, ECN, Stork, Schelde and Sydkraft co-operate. Hospitals are identified as an attractive initial market for cogeneration direct internal reforming-molten carbonate fuel cell (DIR-MCFC) systems in the size of 400 kWe. Innovative system and stack design concepts are being developed for this application. The `SMARTER' system, based on DIR stacks, combines high electric efficiency and a wide operational window with optimal system simplicity and low cost.

  13. Progress of MCFC stack technology at Toshiba

    SciTech Connect

    Hori, M.; Hayashi, T.; Shimizu, Y.

    1996-12-31

    Toshiba is working on the development of MCFC stack technology; improvement of cell characteristics, and establishment of separator technology. For the cell technology, Toshiba has concentrated on both the restraints of NiO cathode dissolution and electrolyte loss from cells, which are the critical issues to extend cell life in MCFC, and great progress has been made. On the other hand, recognizing that the separator is one of key elements in accomplishing reliable and cost-competitive MCFC stacks, Toshiba has been accelerating the technology establishment and verification of an advanced type separator. A sub-scale stack with such a separator was provided for an electric generating test, and has been operated for more than 10,000 hours. This paper presents several topics obtained through the technical activities in the MCFC field at Toshiba.

  14. R&D of MCFC matrix for long term operation

    SciTech Connect

    Nishimura, Takashi; Fujita, Yoji; Urushibata, Hiroaki; Sasaki, Akira

    1996-12-31

    Long term operation is an essential subject in the commercialization of the Molten Carbonate Fuel Cell (MCFC). Material stability is important for the development of the MCFC. particularly for long term operation. In this paper, the specification and the stabilization of MCFC matrix arc investigated, with the aim of producing 40000 hours of operation. It is common knowledge that matrix thickness has a large influence on shorting time, as shorting is caused by the dissolution of the nickel oxide cathodes. Therefore, the optimum thickness of a matrix designed for 40000 hours operation without the nickel shorting was sought. The influences of different electrolytes and matrix specifications on the shorting time were measured with accelerated cell tests. The internal resistance of the matrix was also estimated. Gamma( {gamma} )-lithium aluminate (LiAlO{sub 2}) powder with a sub-micron particle diameter is commonly used for a raw material of matrix to retain molten carbonate electrolytes. This is because most researchers found that {gamma}-LiA1O{sub 2} was the most stable material in the MCFC environment among the three allotropic forms alpha ( {alpha} ), beta ( {beta} ), and {gamma}. However. two problems with the stability of {gamma} -LiAlO{sub 2} are being vigorously discussed. especially in Japan: particle growth causes decreasing electrolyte retention, and the transformation of {gamma} to {alpha}. This transformation contradicts the accepted opinion that {gamma} is the most stable form. In this paper, the particle growth and the phase transformation of LiAlO{sub 2} are examined with post-test analyses. The influence of matrix degradation on cell performance is also considered.

  15. The carbon dioxide concentrator by using MCFC

    NASA Astrophysics Data System (ADS)

    Sugiura, Kimihiko; Takei, Kenji; Tanimoto, Kazumi; Miyazaki, Yoshinori

    The removal characteristics of CO 2 in molten carbonate fuel cell (MCFC) were elucidated by the single cell whose electrode area was 81 cm 2 and electrolyte was 52Li 2CO 3/48Na 2CO 3. The experimental value of the CO 2 removal rate from cathode to anode was almost corresponding to the theoretical value. Cell voltage dropped drastically when concentration of CO 2 in cathode became 15% or less. This tendency showed strikingly, as concentration of O 2 in cathode became lower and lower. The cell performance is influenced with the pO 2/ pCO 2 ratio of the cathode gases, because cell voltage decreases by decreasing the pO 2/ pCO 2 ratio. Therefore, when the pO 2/ pCO 2 ratio is as low as the thermal power plant, it is necessary to add air to cathode for improving the cell performance. Consequently, the reduction target of CO 2 in COP3 can be achieved.

  16. Test results of a 2 kW internal manifold MCFC stack

    SciTech Connect

    Lim, H C; Seol, J H; Ahn, K S

    1996-01-01

    A R&D program on MCFC, of which current target is to establish the fundamental technology through fabricating a 2k-W stack with the performance higher than 0.8V at 150mA/cm{sup 2}, has been started since 1993. The program consisted of two phases : a AW class MCFC stack and the test facility will be constructed and operated during the first phase (1993-1996) and then a 100k-W MCFC system will be constructed in the second phase (1997-2002) on the basement of first phase results. From this strategy, KEPRI former the MCFC developing group with Korea Institute of Science and Technology (KIST) and Samsung Heavy Industry (SHI) for fabricating, operating and evaluating of 2k-W MCFC stack. This paper presents the results of this first phase program and some of the problems experienced during its operation and fabrication of stack components. Specification of the stack under operation is shown in Table 1.

  17. Electrolyte loss in corrosion of 30Cr-45Ni-1Al-0.03 Y-Fe alloy for MCFC separator

    SciTech Connect

    Masamura, Katsumi; Ohe, Koichiro; Takemura, Masahiro

    1996-12-31

    To establish high performance of MCFC, a new high corrosion resistant alloy (30%Cr-45%Ni-1 %Al-0.03%Y-Fe) for MCFC separator has been developed. The developed alloy has good corrosion resistance for both anode and cathode environments. On the other hand, one of the main factors to determine the life time of MCFC stack is electrolyte loss. A potential danger of electrolyte loss cased by corrosion of metal components is pointed out. Basic mechanism of electrolyte loss is proposed according to following reactions. High Cr content alloy such as type 310S(25%Cr-20%Ni) has disadvantages in view of electrolyte loss in spite of high corrosion resistance. It is said that the dissolution of Cr ion into electrolyte is detrimental for electrolyte loss, because a mole of CrO{sub 4}{sup 2+} ion combines 2 moles of K{sup +} ions as K{sub 2}CrO{sub 4}, while a mole of Fe{sup 3+} ion combine a mole of Li{sup +} ion as LiFeO{sub 2}. To understand the mechanism of electrolyte loss due to corrosion of metal component, the distribution of metal ions in oxide and molten salt were studied.

  18. Development of 1000kW-class MCFC pilot plant

    SciTech Connect

    Ooue, M.; Yasue, H.; Takasu, K.; Tsuchitori, T.

    1996-12-31

    This pilot plant is a part of the New Sunshine Program which has proceeded by the Agency of Industrial Science and Technology of the Ministry of International Trade and Industry. MCFC Research Association is entrusted with the development of the pilot plant, and constructing it at Kawagoe site. Following items will be verified by this pilot plant operation. (a) Development of 250kW class stack and confirmation of stack performance and decay rate. (b) System verification such as basic process, control system and operation characteristics, toward commercialization. (c) To get design data for demonstration plant.

  19. Long term operation of the 100-cm{sup 2} class single cell of MCFC

    SciTech Connect

    Tanimoto, Kazumi; Yanagida, Masahiro; Kojima, Toshikatsu

    1996-12-31

    The R&D on Molten Carbonate Fuel Cell (MCFC) is proceeding as one of the New Sun Shine Project sponsored by Japanese government. In ONRI (Osaka National Research Institute), the tested MCFCs were assembled with the state-of-the-art components and operated under the load condition for 40000 hours and 34000 hours. We analyzed the performance reduction.

  20. Dynamic Analysis of Mcfc Porous Electrode

    NASA Astrophysics Data System (ADS)

    Lee, Gwo-Lin Kevin

    1992-01-01

    The intent of this work is to develop AC impedance measurements, in combination with other methods, as a tool to determine the relative importance of various resistance sources in the multi-step process occurring at a gas-diffusion porous electrode. In particular, the case of a MCFC cathode is studied. The goals of this study are: (1) elucidation of electrode mechanism; (2) analysis of the porous electrode performance for the purpose of optimizing design; and (3) developing the capabilities of AC impedance as an index of long-term cell performance decay. The oxygen reduction reaction of molten carbonate fuel cell and the corresponding kinetic as well as transport parameters were tried to be estimated by using impedance techniques combining with other electrochemical methods from flag, wire and rotating disk electrodes in pot cell as well as porous electrode in lab cell. The dominant pathway for oxygen reduction in 62%Li _2CO_3/38%K _2CO_3 melt at 650^circC is via superoxide ions. This follows from flag electrode impedance results indicating that O_sp{2}{ -}/CO_2 mixed diffusion is the dominant source of resistance. The polarization behavior of gas-diffusion porous electrodes has been analyzed in terms of individual voltage loss and overall voltage loss. In most cases, the optimal electrolyte filling will be obtained when the dominant source of voltage loss switches from ohmic or mass transfer resistances to kinetic activation resistance, and similar behavior for optimal electrode thickness. Pressurized operation is favorable for performance if the reaction mechanism follows the superoxide mechanism, but not if the peroxide path dominates. A distributed-network approach has been developed and it is concluded that a digital simulation of AC-superimposed -on-DC impedance of a porous electrode is possible and helpful. Kinetic activation and mass transfer resistances are extracted separate and conclude that both peroxide and superoxide contribute the oxygen reduction

  1. Ammonia synthesis and ER-MCFC-technology - a profitable combination?

    SciTech Connect

    Dijkema, G.P.J.; Vervoort, J.; Daniels, R.J.E.; Luteijn, C.P.

    1996-12-31

    Similar to stand-alone ER-MCFC power systems industrial ammonia production facilities include hydrogen-rich synthesis-gas production. Therefore, integration of ER-MCFC stacks in a conventional industrial ammonia plant was investigated. By preliminary process design calculations three promising process structures were evaluated: (1) ER-MCFC is fed by the ammonia plant`s steam-reformer; anode off-gas to firing (2) similar to structure 1; in this case the anode off-gas is redirected to the ammonia process (3) ER-MCFC is fed by ammonia-synthesis purge gas The results indicate that for options 1 and 3 a return-on-investment for the ER-MCFC of around 8% is achievable at a stack cost of $250/kW and a revenue of 7c/kWh. Option 2 is not profitable, because of the associated reduction in ammonia production. The degree of hydrogen-utilization in the ER-MCFC to be selected for maximum profit varies with the process structure and indicates that there is scope for ER-MCFC stacks which operate at low hydrogen-utilization.

  2. MCFC power plant with CO{sub 2} separation

    SciTech Connect

    Kinoshita, Noboru

    1996-12-31

    Fuel cell power plant has been developed for many years with expectation of high system efficiency. In the meantime the gas turbine combined cycle has shown its considerable progress in improving system efficiency. Fuel cell power plant will no longer be attractive unless it exceeds the gas turbine combined cycle at least in the system efficiency. It is said CO{sub 2} separation could improve the efficiency of fuel cell power plant. IHI has developed the CO{sub 2} separator for fuel cell power plant. This study describes that the CO{sub 2} separator can increase the efficiency of the molten carbonate fuel cell (MCFC) power plant by 5% and the expected efficiency reaches 63 % in HHV basis.

  3. Status of MCFC stack development at Hitachi

    SciTech Connect

    Takashima, S.; Kahara, T.; Takeuchi, M.

    1996-12-31

    Hitachi, Ltd. has been developing Molten Carbonate Fuel Cells in the New Sunshine project in Japan, and Hitachi is taking part in the development of 1,000kW MCFC pilot plant at Kawagoe. Hitachi is engaged in system planning of the 1,000kW pilot plant, design and manufacturing of the reformer subsystem and the fuel cell subsystem, and design and manufacturing of the 250kW stacks for the 1,000kW plant. The 250kW stacks are developed on the basis of the results of the 100kW stack in 1993 and the following 25kW stack in 1994. In parallel to the stack development, Hitachi is also conducting researches for long endurance cells and stacks. In addition to the researches for anode, cathode, electrolyte, and electrolyte matrix, improvement of temperature distribution in stacks is investigated to extend the stack life. This paper describes the planning status of the 250kW stacks for the 1,000kW MCFC plant and the developing status of stack cooling method for longer life.

  4. Operation characteristics of a multiple type MCFC

    SciTech Connect

    Kuroe, S.; Kamo, T.; Fujimura, H.; Kahara, T.

    1996-12-31

    Multiple type structure of MCFC of which the separator of the cell is divided by four element cells has been studied. For the stable operation of this type cell, the effect of gas flow rate and temperature distribution on the cell voltage should be clear. In order to clarify these characteristics, a small sized mimic model has been made and tested. The flow rate distribution for the four element cells were varied and cell voltage and temperature distribution were measured for each cell. The decrease in cell voltage and the increase in maximum temperature became remarkable when the apparent utilization factor for one element cell became over 100%. The calculated results agreed fairly good with test results.

  5. MCFC integrated system in a biodiesel production process

    NASA Astrophysics Data System (ADS)

    Urbani, F.; Freni, S.; Galvagno, A.; Chiodo, V.

    2011-03-01

    The continuous increasing in biodiesel production by transesterification process is leading to an excess of glycerol production as a byproduct. The utilization of this huge amount of glycerol appears as a not easy solvable problem and thus several authors have proposed alternative ways. The integration of the main production process with a glycerol feed molten carbonate fuel cells bottoming cycle, to satisfy plant energy requirements, seems to be one of the most promising one. The proposed paper reports the main results obtained by authors in the framework of an investigation on a possible use of glycerol as energy sources for a real pilot plant for biodiesel production. An overall evaluation of worldwide biodiesel production plants was made and especially about the production capacity in European Union in the last decade. To make a more detailed study, authors were taken into account a real production plant. After a preliminary step, purported to plant mass and energy flows determination, authors considered the integration of a bottoming cycle based on: (i) steam reforming of glycerol for syn-gas production; (ii) molten carbonate fuel cells (MCFC) system supplied by syn-gas for heat and electricity production. A mathematical model, based on experimental data, has been developed to calculate mass and energy balances for the proposed plant lay-out as well as plant energy efficiency enhancement has been determined. Results have evidenced the feasibility of this process and demonstrated that plant integrated with bottoming cycle can reach a very high level of energy self-production.

  6. Operation result of 40kW class MCFC pilot plant

    SciTech Connect

    Saitoh, H.; Hatori, S.; Hosaka, M.; Uematsu, H.

    1996-12-31

    Ishikawajima-Harima Heavy Industries Co., Ltd. developed unique Molten Carbonate Fuel Cell (MCFC) system based on our original concept. To demonstrate the possibility of this system, based on MCFC technology of consigned research from New Energy and Industrial Technology Development Organization (NEDO) in Japan, we designed 40kW class MCFC pilot plant which had all equipments required as a power plant and constructed in our TO-2 Technical Center. This paper presents the test results of the plant.

  7. Development of a new electrolyte matrix for MCFC

    SciTech Connect

    Nagashima, I.; Higaki, K.; Terada, S.; Suemitsu, T.

    1996-12-31

    To prolong the life of cell is one of the most important issues for MCFC to be brought into actual application. In this respect, investigators have been proposing the addition of tungstate salt such as K2WO4 into MCFC electrolyte, which is supposed effectively to reduce the sintering of anode probably by precipitates formed through the reduction of tungstate with dissolved hydrogen near the anode surface. In this research, such effect upon sintering of anode was quantitatively examined by out-of-cell tests and the validity of above assumption for the mechanism was confirmed. Also other effects of tungstate salt addition into electrolyte, such upon corrosion of separator, solubility of cathode, stability of matrix substrates (LiAlO{sub 2}) were investigated.

  8. Simulated coal gas MCFC power plant system verification. Final report

    SciTech Connect

    1998-07-30

    The objective of the main project is to identify the current developmental status of MCFC systems and address those technical issues that need to be resolved to move the technology from its current status to the demonstration stage in the shortest possible time. The specific objectives are separated into five major tasks as follows: Stack research; Power plant development; Test facilities development; Manufacturing facilities development; and Commercialization. This Final Report discusses the M-C power Corporation effort which is part of a general program for the development of commercial MCFC systems. This final report covers the entire subject of the Unocal 250-cell stack. Certain project activities have been funded by organizations other than DOE and are included in this report to provide a comprehensive overview of the work accomplished.

  9. M-C Power commercialization program for MCFC power plants

    NASA Astrophysics Data System (ADS)

    Cámara, E. H.; Schora, F. C.

    1992-01-01

    M-C Power Corporation was established by the Institute of Gas Technology (IGT) to develop, manufacture, market, sell and service commercial MCFC power plants using IGT's IMHEX® fuel cell stack concept. M-C Power has created an integrated commercialization program to develop a market-responsive, natural gas-fueled MCFC power plant. M-C Power's market entry offering will range from 500 kW to 3 MW and will be designed for on-site and distributed power applications. Future products will include a wider range of sizes for distributed power and power plants for dispersed (30-50 MW) and base load ( > 100 MW) power generation, the latter fueled by coal-derived gases. M-C Power Corporation has established the world's most advanced MCFC components and stack manufacturing facilities at its plant in Burr Ridge, IL, capable of producing 3 MW/year of stacks based on one shift per day, five days per week operation. This capacity can be increased to 12 MW/year by adding one tape casting machine and operating three shifts per day for 330 days/year. An industry group has been formed to guide, support, and stimulate the IMHEX® Commercialization Program. This group is called the Alliance to Commercialize Carbonate Technology (ACCT). ACCT members include electric, gas and combination utilities as well as pipeline companies and potential industrial users. In addition, the program enjoys wide support from government, industry and research institutions.

  10. ANL's research and development of alternative components for MCFC's

    SciTech Connect

    Kucera, G.H.; Brown, A.P.; Roche, M.; Chu, D.; Indacochea, E.

    1992-01-01

    Molten carbonate fuel cell (MCFC) systems are currently limited by several technical problems. The objectives of this project are to focus on these problems and develop materials . and cell components that will ameliorate or eliminate them. Specifically, new ceramic materials are being investigated for dimensionally stable electrode materials with improved chemical and electrochemical properties over the present NiO cathode and Ni/Cr and Ni/Al anodes. Also, altemative electrolyte formulations to the present Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} are being studied.

  11. A simple high-performance matrix-free biomass molten carbonate fuel cell without CO2 recirculation

    PubMed Central

    Lan, Rong; Tao, Shanwen

    2016-01-01

    In previous reports, flowing CO2 at the cathode is essential for either conventional molten carbonate fuel cells (MCFCs) based on molten carbonate/LiAlO2 electrolytes or matrix-free MCFCs. For the first time, we demonstrate a high-performance matrix-free MCFC without CO2 recirculation. At 800°C, power densities of 430 and 410 mW/cm2 are achieved when biomass—bamboo charcoal and wood, respectively–is used as fuel. At 600°C, a stable performance is observed during the measured 90 hours after the initial degradation. In this MCFC, CO2 is produced at the anode when carbon-containing fuels are used. The produced CO2 then dissolves and diffuses to the cathode to react with oxygen in open air, forming the required CO32− or CO42− ions for continuous operation. The dissolved O2− ions may also take part in the cell reactions. This provides a simple new fuel cell technology to directly convert carbon-containing fuels such as carbon and biomass into electricity with high efficiency. PMID:27540588

  12. A simple high-performance matrix-free biomass molten carbonate fuel cell without CO2 recirculation.

    PubMed

    Lan, Rong; Tao, Shanwen

    2016-08-01

    In previous reports, flowing CO2 at the cathode is essential for either conventional molten carbonate fuel cells (MCFCs) based on molten carbonate/LiAlO2 electrolytes or matrix-free MCFCs. For the first time, we demonstrate a high-performance matrix-free MCFC without CO2 recirculation. At 800°C, power densities of 430 and 410 mW/cm(2) are achieved when biomass-bamboo charcoal and wood, respectively-is used as fuel. At 600°C, a stable performance is observed during the measured 90 hours after the initial degradation. In this MCFC, CO2 is produced at the anode when carbon-containing fuels are used. The produced CO2 then dissolves and diffuses to the cathode to react with oxygen in open air, forming the required [Formula: see text] or [Formula: see text] ions for continuous operation. The dissolved [Formula: see text] ions may also take part in the cell reactions. This provides a simple new fuel cell technology to directly convert carbon-containing fuels such as carbon and biomass into electricity with high efficiency.

  13. Demonstration of direct internal reforming for MCFC power plants

    SciTech Connect

    Aasberg-Petersen, K.; Christensen, P.S.; Winther, S.K.

    1996-12-31

    The conversion of methane into hydrogen for an MCFC by steam reforming is accomplished either externally or internally in the stack. In the case of external reforming the plant electrical efficiency is 5% abs. lower mainly because more parasitic power is required for air compression for stack cooling. Furthermore, heat produced in the stack must be transferred to the external reformer to drive the endothermic steam reforming reaction giving a more complex plant lay-out. A more suitable and cost effective approach is to use internal steam reforming of methane. Internal reforming may be accomplished either by Indirect Internal Reforming (DIR) and Direct Internal Reforming (DIR) in series or by DIR-only as illustrated. To avoid carbon formation in the anode compartment higher hydrocarbons in the feedstock are converted into hydrogen, methane and carbon oxides by reaction with steam in ail adiabatic prereformer upstream the fuel cell stack. This paper discusses key elements of the desire of both types of internal reforming and presents data from pilot plants with a combined total of more than 10,000 operating hours. The project is being carried out as part of the activities of the European MCFC Consortium ARGE.

  14. Performance, Performance System, and High Performance System

    ERIC Educational Resources Information Center

    Jang, Hwan Young

    2009-01-01

    This article proposes needed transitions in the field of human performance technology. The following three transitions are discussed: transitioning from training to performance, transitioning from performance to performance system, and transitioning from learning organization to high performance system. A proposed framework that comprises…

  15. Development of advanced concepts for DIR-MCFC cogeneration applications in the European Market

    SciTech Connect

    Kortbeek, P.J.; Ottervanger, R.G.; Dicks, A.L.

    1996-12-31

    Early 1996 a three year (1996 - 1998) joint European project was launched under the name {open_quote}Advanced DIR-MCFC Development{close_quote}, aiming at the development of Direct Internal Reforming (DIR) Molten Carbonate Fuel Cell (MCFC) systems for cogeneration applications for the European market. In this project participate: Brandstofcel Nederland BV (BCN), British Gas pic (BG), Gaz de France (GDF), Netherlands Energy Research foundation (ECN), Stork, Royal Schelde and Sydkraft AB. The European Fuel Cell User Group (EFCUG) supports the project as an advisory board. Whereas the US and Japanese programmes are aimed at large-scale demonstrations of the MCFC technology, this project focusses on the development of concepts and technology, required for MCFC systems that will be competative on the cogeneration market. The project partners provide the essential expertise: from end-user, system engineering, stack development up to fundamental material research.

  16. Study of LiFeO 2 coated NiO as cathodes for MCFC by electrochemical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Bo; Yu, Qing-chun; Wang, Hui-min; Chen, Gang; Hu, Ke-ao

    LiFeO 2 was coated on porous NiO cathode using a simple combustion process. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed in the cathode characterizations. The electrochemical behaviors of LiFeO 2 coated NiO cathode (LFO-NiO) were also evaluated in a molten 62 mol% Li 2CO 3 + 38 mol% K 2CO 3 eutectic at 650 °C under the standard cathode gas condition by electrochemical impedance spectroscopy (EIS). The impedance response of the NiO and LFO-NiO at different immersion time is characterized by the presence of depressed semicircles in the high frequency range changing over into the lines with the angle of which observed with the real axis differing 45° or 90° in the low frequency range. The experimental Nyquist plots can be well analyzed theoretically with a modified model based on the well known Randles-Ershler equivalent circuit model. In the new model, the double layer capacity ( Cd) is replaced by the parallel combination of Cd and b/ ω to take into consideration the non-uniform of electric field at the electrode/electrolyte interface owing to the roughness of electrode surface. The LFO-NiO showed a lower dissolution and a good catalytic efficiency close to the state-of-the-art NiO value. In the unit cell test, the performance of the cell composed of LiFeO 2 coated NiO cathode maintained more stable values than that of the cell composed of NiO cathode. Thus the cathode prepared with coating method to coat LiFeO 2 on the surface of NiO cathode is able to reduce the solubility of NiO to lengthen the lifetime of MCFC while maintaining the advantages of NiO cathode.

  17. High performance polymer development

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.

    1991-01-01

    The term high performance as applied to polymers is generally associated with polymers that operate at high temperatures. High performance is used to describe polymers that perform at temperatures of 177 C or higher. In addition to temperature, other factors obviously influence the performance of polymers such as thermal cycling, stress level, and environmental effects. Some recent developments at NASA Langley in polyimides, poly(arylene ethers), and acetylenic terminated materials are discussed. The high performance/high temperature polymers discussed are representative of the type of work underway at NASA Langley Research Center. Further improvement in these materials as well as the development of new polymers will provide technology to help meet NASA future needs in high performance/high temperature applications. In addition, because of the combination of properties offered by many of these polymers, they should find use in many other applications.

  18. Molten Carbonate Fuel Cell (MCFC) product development test

    NASA Astrophysics Data System (ADS)

    1995-02-01

    M-C Power Corporation will design, fabricate, install, test, and evaluate a 250 kW Proof-of-Concept Molten Carbonate Fuel Cell (MCFC) Power Plant. The plant is to be located at the Naval Air Station Miramar in San Diego, California. This report summarizes the technical progress that has occurred in conjunction with this project in 1994. M-C Power has completed the tape casting and sintering of cathodes and is proceeding with the tape casting and sintering of anodes for the first 250 cell stack. M-C Power and San Diego Gas and Electric (SDG&E) relocated the fuel cell demonstration project to an alternate site at the Naval Air Station Miramar. For the new project location, an Environmental Assessment has been prepared by the Department of Energy in compliance with the National Environmental Policy Act of 1969. The Environmental Assessment resulted in a categorical exclusion of the proposed action from all environmental permit requirements. Bechtel Corporation has completed the reformer process design coordination, a Process Description, the Pipe and Instrumentation Diagrams, a Design Criteria Document and General Project Requirement Document. Bechtel developed the requirements for soils investigation report and issued the following equipment bid packages to the suppliers for bids: inverter, reformer, desulfurization vessels, hot gas recycle blower, heat recovery steam generator, and recycle gas cooler. SDG&E has secured necessary site permits, conducted soils investigations, and is working on the construction plan. They are in final negotiations with the US Navy on a site agreement. Site drawings are required for finalization of the agreement.

  19. Advanced component development of MCFC technology at M-C Power

    SciTech Connect

    Erickson, D.S.; Haugh, E.J.; Benjamin, T.G.

    1996-12-31

    M-C Power Corporation (MCP) was founded in 1987 to commercialize Molten Carbonate Fuel Cell (MCFC) stacks. The first generation of active area cell components were successfully scaled-up from the 100-cm{sup 2} area laboratory scale to continuous production of commercial-area (1-m) components. These components have been tested in five commercial-area subscale (20-kW) stacks and one commercial-scale (250-kW) stack. The second 250 kW stack is being installed in the power plant for operation in late 1996 and components have already been manufactured for the third 250-kW stack which is scheduled to go on-line in the middle of 1997. Concurrent with commercial-area (1-m{sup 2}) active component manufacturing has been an ongoing effort to develop and test advanced component technologies that will enable MCP to meet its future cost and performance goals. The primary goal is to lower the total cell package cost, while attaining improvements in cell performance and endurance. This work is being completed through analysis of the cost drivers for raw materials and manufacturing techniques. A program is in place to verify the performance of the lower cost materials through pressurized (3 atm) bench scale (100-cm{sup 2}) cell tests. Bench-scale cell testing of advanced active area components has shown that simultaneous cost reduction and improvements in the performance and endurance are attainable. Following performance verification at the bench scale level, scale-up of the advanced component manufacturing processes to commercial-area has been ongoing in the past year. The following sections discuss some of the performance improvements and reductions in cost that have been realized.

  20. High performance systems

    SciTech Connect

    Vigil, M.B.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  1. High Performance Polymers

    NASA Technical Reports Server (NTRS)

    Venumbaka, Sreenivasulu R.; Cassidy, Patrick E.

    2003-01-01

    This report summarizes results from research on high performance polymers. The research areas proposed in this report include: 1) Effort to improve the synthesis and to understand and replicate the dielectric behavior of 6HC17-PEK; 2) Continue preparation and evaluation of flexible, low dielectric silicon- and fluorine- containing polymers with improved toughness; and 3) Synthesis and characterization of high performance polymers containing the spirodilactam moiety.

  2. High performance polymeric foams

    SciTech Connect

    Gargiulo, M.; Sorrentino, L.; Iannace, S.

    2008-08-28

    The aim of this work was to investigate the foamability of high-performance polymers (polyethersulfone, polyphenylsulfone, polyetherimide and polyethylenenaphtalate). Two different methods have been used to prepare the foam samples: high temperature expansion and two-stage batch process. The effects of processing parameters (saturation time and pressure, foaming temperature) on the densities and microcellular structures of these foams were analyzed by using scanning electron microscopy.

  3. High performance parallel architectures

    SciTech Connect

    Anderson, R.E. )

    1989-09-01

    In this paper the author describes current high performance parallel computer architectures. A taxonomy is presented to show computer architecture from the user programmer's point-of-view. The effects of the taxonomy upon the programming model are described. Some current architectures are described with respect to the taxonomy. Finally, some predictions about future systems are presented. 5 refs., 1 fig.

  4. High-Performance Happy

    ERIC Educational Resources Information Center

    O'Hanlon, Charlene

    2007-01-01

    Traditionally, the high-performance computing (HPC) systems used to conduct research at universities have amounted to silos of technology scattered across the campus and falling under the purview of the researchers themselves. This article reports that a growing number of universities are now taking over the management of those systems and…

  5. High Performance, Dependable Multiprocessor

    NASA Technical Reports Server (NTRS)

    Ramos, Jeremy; Samson, John R.; Troxel, Ian; Subramaniyan, Rajagopal; Jacobs, Adam; Greco, James; Cieslewski, Grzegorz; Curreri, John; Fischer, Michael; Grobelny, Eric; George, Alan; Aggarwal, Vikas; Patel, Minesh; Some, Raphael

    2006-01-01

    With the ever increasing demand for higher bandwidth and processing capacity of today's space exploration, space science, and defense missions, the ability to efficiently apply commercial-off-the-shelf (COTS) processors for on-board computing is now a critical need. In response to this need, NASA's New Millennium Program office has commissioned the development of Dependable Multiprocessor (DM) technology for use in payload and robotic missions. The Dependable Multiprocessor technology is a COTS-based, power efficient, high performance, highly dependable, fault tolerant cluster computer. To date, Honeywell has successfully demonstrated a TRL4 prototype of the Dependable Multiprocessor [I], and is now working on the development of a TRLS prototype. For the present effort Honeywell has teamed up with the University of Florida's High-performance Computing and Simulation (HCS) Lab, and together the team has demonstrated major elements of the Dependable Multiprocessor TRLS system.

  6. High performance steam development

    SciTech Connect

    Duffy, T.; Schneider, P.

    1995-12-31

    DOE has launched a program to make a step change in power plant to 1500 F steam, since the highest possible performance gains can be achieved in a 1500 F steam system when using a topping turbine in a back pressure steam turbine for cogeneration. A 500-hour proof-of-concept steam generator test module was designed, fabricated, and successfully tested. It has four once-through steam generator circuits. The complete HPSS (high performance steam system) was tested above 1500 F and 1500 psig for over 102 hours at full power.

  7. High Performance FORTRAN

    NASA Technical Reports Server (NTRS)

    Mehrotra, Piyush

    1994-01-01

    High performance FORTRAN is a set of extensions for FORTRAN 90 designed to allow specification of data parallel algorithms. The programmer annotates the program with distribution directives to specify the desired layout of data. The underlying programming model provides a global name space and a single thread of control. Explicitly parallel constructs allow the expression of fairly controlled forms of parallelism in particular data parallelism. Thus the code is specified in a high level portable manner with no explicit tasking or communication statements. The goal is to allow architecture specific compilers to generate efficient code for a wide variety of architectures including SIMD, MIMD shared and distributed memory machines.

  8. High Performance Window Retrofit

    SciTech Connect

    Shrestha, Som S; Hun, Diana E; Desjarlais, Andre Omer

    2013-12-01

    The US Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and Traco partnered to develop high-performance windows for commercial building that are cost-effective. The main performance requirement for these windows was that they needed to have an R-value of at least 5 ft2 F h/Btu. This project seeks to quantify the potential energy savings from installing these windows in commercial buildings that are at least 20 years old. To this end, we are conducting evaluations at a two-story test facility that is representative of a commercial building from the 1980s, and are gathering measurements on the performance of its windows before and after double-pane, clear-glazed units are upgraded with R5 windows. Additionally, we will use these data to calibrate EnergyPlus models that we will allow us to extrapolate results to other climates. Findings from this project will provide empirical data on the benefits from high-performance windows, which will help promote their adoption in new and existing commercial buildings. This report describes the experimental setup, and includes some of the field and simulation results.

  9. Thermodynamic analysis of biofuels as fuels for high temperature fuel cells

    NASA Astrophysics Data System (ADS)

    Milewski, Jarosław; Bujalski, Wojciech; Lewandowski, Janusz

    2013-02-01

    Based on mathematical modeling and numerical simulations, applicativity of various biofuels on high temperature fuel cell performance are presented. Governing equations of high temperature fuel cell modeling are given. Adequate simulators of both solid oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC) have been done and described. Performance of these fuel cells with different biofuels is shown. Some characteristics are given and described. Advantages and disadvantages of various biofuels from the system performance point of view are pointed out. An analysis of various biofuels as potential fuels for SOFC and MCFC is presented. The results are compared with both methane and hydrogen as the reference fuels. The biofuels are characterized by both lower efficiency and lower fuel utilization factors compared with methane. The presented results are based on a 0D mathematical model in the design point calculation. The governing equations of the model are also presented. Technical and financial analysis of high temperature fuel cells (SOFC and MCFC) are shown. High temperature fuel cells can be fed by biofuels like: biogas, bioethanol, and biomethanol. Operational costs and possible incomes of those installation types were estimated and analyzed. A comparison against classic power generation units is shown. A basic indicator net present value (NPV) for projects was estimated and commented.

  10. High Performance Buildings Database

    DOE Data Explorer

    The High Performance Buildings Database is a shared resource for the building industry, a unique central repository of in-depth information and data on high-performance, green building projects across the United States and abroad. The database includes information on the energy use, environmental performance, design process, finances, and other aspects of each project. Members of the design and construction teams are listed, as are sources for additional information. In total, up to twelve screens of detailed information are provided for each project profile. Projects range in size from small single-family homes or tenant fit-outs within buildings to large commercial and institutional buildings and even entire campuses. The database is a data repository as well. A series of Web-based data-entry templates allows anyone to enter information about a building project into the database. Once a project has been submitted, each of the partner organizations can review the entry and choose whether or not to publish that particular project on its own Web site.

  11. High Performance Liquid Chromatography

    NASA Astrophysics Data System (ADS)

    Talcott, Stephen

    High performance liquid chromatography (HPLC) has many applications in food chemistry. Food components that have been analyzed with HPLC include organic acids, vitamins, amino acids, sugars, nitrosamines, certain pesticides, metabolites, fatty acids, aflatoxins, pigments, and certain food additives. Unlike gas chromatography, it is not necessary for the compound being analyzed to be volatile. It is necessary, however, for the compounds to have some solubility in the mobile phase. It is important that the solubilized samples for injection be free from all particulate matter, so centrifugation and filtration are common procedures. Also, solid-phase extraction is used commonly in sample preparation to remove interfering compounds from the sample matrix prior to HPLC analysis.

  12. High Performance Work Practices and Firm Performance.

    ERIC Educational Resources Information Center

    Department of Labor, Washington, DC. Office of the American Workplace.

    A literature survey established that a substantial amount of research has been conducted on the relationship between productivity and the following specific high performance work practices: employee involvement in decision making, compensation linked to firm or worker performance, and training. According to these studies, high performance work…

  13. High Performance Parallel Architectures

    NASA Technical Reports Server (NTRS)

    El-Ghazawi, Tarek; Kaewpijit, Sinthop

    1998-01-01

    Traditional remote sensing instruments are multispectral, where observations are collected at a few different spectral bands. Recently, many hyperspectral instruments, that can collect observations at hundreds of bands, have been operational. Furthermore, there have been ongoing research efforts on ultraspectral instruments that can produce observations at thousands of spectral bands. While these remote sensing technology developments hold great promise for new findings in the area of Earth and space science, they present many challenges. These include the need for faster processing of such increased data volumes, and methods for data reduction. Dimension Reduction is a spectral transformation, aimed at concentrating the vital information and discarding redundant data. One such transformation, which is widely used in remote sensing, is the Principal Components Analysis (PCA). This report summarizes our progress on the development of a parallel PCA and its implementation on two Beowulf cluster configuration; one with fast Ethernet switch and the other with a Myrinet interconnection. Details of the implementation and performance results, for typical sets of multispectral and hyperspectral NASA remote sensing data, are presented and analyzed based on the algorithm requirements and the underlying machine configuration. It will be shown that the PCA application is quite challenging and hard to scale on Ethernet-based clusters. However, the measurements also show that a high- performance interconnection network, such as Myrinet, better matches the high communication demand of PCA and can lead to a more efficient PCA execution.

  14. High performance sapphire windows

    NASA Technical Reports Server (NTRS)

    Bates, Stephen C.; Liou, Larry

    1993-01-01

    High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire.

  15. High performing micromachined retroreflector

    NASA Astrophysics Data System (ADS)

    Lundvall, Axel; Nikolajeff, Fredrik; Lindstrom, Tomas

    2003-10-01

    This paper reports on the realization of a type of micromachined retroreflecting sheeting material. The geometry presented has high reflection efficiency even at large incident angles, and it can be manufactured through polymer replication techniques. The paper consists of two parts: A theoretical section outlining the design parameters and their impact on the optical performance, and secondly, an experimental part comprising both manufacturing and optical evaluation for a candidate retroreflecting sheet material in traffic control devices. Experimental data show that the retroreflecting properties are promising. The retroreflector consists of a front layer of densely packed spherical microlenses, a back surface of densely packed spherical micromirrors, and a transparent spacer layer. The thickness of the spacer layer determines in part the optical characteristics of the retroreflector.

  16. High Performance Work Systems and Firm Performance.

    ERIC Educational Resources Information Center

    Kling, Jeffrey

    1995-01-01

    A review of 17 studies of high-performance work systems concludes that benefits of employee involvement, skill training, and other high-performance work practices tend to be greater when new methods are adopted as part of a consistent whole. (Author)

  17. Commoditization of High Performance Storage

    SciTech Connect

    Studham, Scott S.

    2004-04-01

    The commoditization of high performance computers started in the late 80s with the attack of the killer micros. Previously, high performance computers were exotic vector systems that could only be afforded by an illustrious few. Now everyone has a supercomputer composed of clusters of commodity processors. A similar commoditization of high performance storage has begun. Commodity disks are being used for high performance storage, enabling a paradigm change in storage and significantly changing the price point of high volume storage.

  18. ANL`s research and development of alternative components for MCFC`s

    SciTech Connect

    Kucera, G.H.; Brown, A.P.; Roche, M.; Chu, D.; Indacochea, E.

    1992-09-01

    Molten carbonate fuel cell (MCFC) systems are currently limited by several technical problems. The objectives of this project are to focus on these problems and develop materials . and cell components that will ameliorate or eliminate them. Specifically, new ceramic materials are being investigated for dimensionally stable electrode materials with improved chemical and electrochemical properties over the present NiO cathode and Ni/Cr and Ni/Al anodes. Also, altemative electrolyte formulations to the present Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} are being studied.

  19. High performance collectors

    NASA Astrophysics Data System (ADS)

    Ogawa, H.; Hozumi, S.; Mitsumata, T.; Yoshino, K.; Aso, S.; Ebisu, K.

    1983-04-01

    Materials and structures used for flat plate solar collectors and evacuated tubular collectors were examined relative to their overall performance to project effectiveness for building heating and cooling and the feasibility of use for generating industrial process heat. Thermal efficiencies were calculated for black paint single glazed, selective surface single glazed, and selective surface double glazed flat plate collectors. The efficiencies of a single tube and central tube accompanied by two side tube collectors were also studied. Techniques for extending the lifetimes of the collectors were defined. The selective surface collectors proved to have a performance superior to other collectors in terms of the average annual energy delivered. Addition of a black chrome-coated fin system to the evacuated collectors produced significant collection efficiency increases.

  20. High Performance Arcjet Engines

    NASA Technical Reports Server (NTRS)

    Kennel, Elliot B.; Ivanov, Alexey Nikolayevich; Nikolayev, Yuri Vyacheslavovich

    1994-01-01

    This effort sought to exploit advanced single crystal tungsten-tantalum alloy material for fabrication of a high strength, high temperature arcjet anode. The use of this material is expected to result in improved strength, temperature resistance, and lifetime compared to state of the art polycrystalline alloys. In addition, the use of high electrical and thermal conductivity carbon-carbon composites was considered, and is believed to be a feasible approach. Highly conductive carbon-carbon composite anode capability represents enabling technology for rotating-arc designs derived from the Russian Scientific Research Institute of Thermal Processes (NIITP) because of high heat fluxes at the anode surface. However, for US designs the anode heat flux is much smaller, and thus the benefits are not as great as in the case of NIITP-derived designs. Still, it does appear that the tensile properties of carbon-carbon can be even better than those of single crystal tungsten alloys, especially when nearly-single-crystal fibers such as vapor grown carbon fiber (VGCF) are used. Composites fabricated from such materials must be coated with a refractory carbide coating in order to ensure compatibility with high temperature hydrogen. Fabrication of tungsten alloy single crystals in the sizes required for fabrication of an arcjet anode has been shown to be feasible. Test data indicate that the material can be expected to be at least the equal of W-Re-HfC polycrystalline alloy in terms of its tensile properties, and possibly superior. We are also informed by our colleagues at Scientific Production Association Luch (NP0 Luch) that it is possible to use Russian technology to fabricate polycrystalline W-Re-HfC or other high strength alloys if desired. This is important because existing engines must rely on previously accumulated stocks of these materials, and a fabrication capability for future requirements is not assured.

  1. High performance cyclone development

    SciTech Connect

    Giles, W.B.

    1981-01-01

    The results of cold flow experiments at atmospheric conditions of an air-shielded 18 in-dia electrocyclone with a central cusped electrode are reported using fine test dusts of both flyash and nickel powder. These results are found to confirm expectations of enhanced performance, similar to earlier work on a 12 in-dia model. An analysis of the combined inertial-electrostatic force field is also presented which identifies general design goals and scaling laws. From this, it is found that electrostatic enhancement will be particularly beneficial for fine dusts in large cyclones. Recommendations for further improvement in cyclone collection efficiency are proposed.

  2. High Performance Magnets

    DTIC Science & Technology

    2000-03-29

    Our efforts in this project were focused on three different materials, namely; interstitial Sm-Fe carbides and nitrides, high energy product Nd2Fe14B ...magnets with MgO addition, and nanocomposite Nd2Fe14B /alpha-Fe consisting of a fine mixture of hard and soft phases. In the Sm-Fe carbides and

  3. High Performance Biocomputation

    DTIC Science & Technology

    2005-03-01

    view, are failed grand challenges include the "War on Cancer " (circa 1970) and the "Decade of the Brain" in which an NIH report in 1990 argued that...ancestors possible. There have been claims made that DNA may be found in preserved ancient bacteria or even in dinosaur bones, but these claims remain highly

  4. Tough high performance composite matrix

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor); Johnston, Norman J. (Inventor)

    1994-01-01

    This invention is a semi-interpentrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide. Provided is an improved high temperature matrix resin which is capable of performing in the 200 to 300 C range. This resin has significantly improved toughness and microcracking resistance, excellent processability, mechanical performance, and moisture and solvent resistances.

  5. High performance steam development

    SciTech Connect

    Duffy, T.; Schneider, P.

    1995-10-01

    Over 30 years ago U.S. industry introduced the world`s highest temperature (1200{degrees}F at 5000 psig) and most efficient power plant, the Eddystone coal-burning steam plant. The highest alloy material used in the plant was 316 stainless steel. Problems during the first few years of operation caused a reduction in operating temperature to 1100{degrees}F which has generally become the highest temperature used in plants around the world. Leadership in high temperature steam has moved to Japan and Europe over the last 30 years.

  6. High Performance YBCO Films

    DTIC Science & Technology

    1992-07-01

    growing high quality MgO films on SrF2 substrates is the oxygen partial pressure during the growth. The x-ray data presented in Fig. 13 indicates a...fluo-ide and quartz substrates. The best result with two buffer layers (MgO and YSZ) on SrF2 was an onset temperature (Tc) of 82K and a transition...With a YSZ buffer an onset temperature of 85K and a transition width of 5K was achieved. Recent success was demonstrated by Neocera ( under a NASA

  7. High Voltage SPT Performance

    NASA Technical Reports Server (NTRS)

    Manzella, David; Jacobson, David; Jankovsky, Robert

    2001-01-01

    A 2.3 kW stationary plasma thruster designed to operate at high voltage was tested at discharge voltages between 300 and 1250 V. Discharge specific impulses between 1600 and 3700 sec were demonstrated with thrust between 40 and 145 mN. Test data indicated that discharge voltage can be optimized for maximum discharge efficiency. The optimum discharge voltage was between 500 and 700 V for the various anode mass flow rates considered. The effect of operating voltage on optimal magnet field strength was investigated. The effect of cathode flow rate on thruster efficiency was considered for an 800 V discharge.

  8. High performance alloy electroforming

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Winkelman, D. M.

    1989-01-01

    Electroformed copper and nickel are used in structural applications for advanced propellant combustion chambers. An improved process has been developed by Bell Aerospace Textron, Inc. wherein electroformed nickel-manganese alloy has demonstrated superior mechanical and thermal stability when compared to previously reported deposits from known nickel plating processes. Solution chemistry and parametric operating procedures are now established and material property data is established for deposition of thick, large complex shapes such as the Space Shuttle Main Engine. The critical operating variables are those governing the ratio of codeposited nickel and manganese. The deposition uniformity which in turn affects the manganese concentration distribution is affected by solution resistance and geometric effects as well as solution agitation. The manganese concentration in the deposit must be between 2000 and 3000 ppm for optimum physical properties to be realized. The study also includes data regarding deposition procedures for achieving excellent bond strength at an interface with copper, nickel-manganese or INCONEL 718. Applications for this electroformed material include fabrication of complex or re-entry shapes which would be difficult or impossible to form from high strength alloys such as INCONEL 718.

  9. High Performance Computing at NASA

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Cooper, D. M. (Technical Monitor)

    1994-01-01

    The speaker will give an overview of high performance computing in the U.S. in general and within NASA in particular, including a description of the recently signed NASA-IBM cooperative agreement. The latest performance figures of various parallel systems on the NAS Parallel Benchmarks will be presented. The speaker was one of the authors of the NAS (National Aerospace Standards) Parallel Benchmarks, which are now widely cited in the industry as a measure of sustained performance on realistic high-end scientific applications. It will be shown that significant progress has been made by the highly parallel supercomputer industry during the past year or so, with several new systems, based on high-performance RISC processors, that now deliver superior performance per dollar compared to conventional supercomputers. Various pitfalls in reporting performance will be discussed. The speaker will then conclude by assessing the general state of the high performance computing field.

  10. Status of Santa Clara MCFC product development test

    SciTech Connect

    Leo, A.J.; O`Shea, T.P.

    1995-08-01

    The objective of the 2MW Santa Clara Demonstration Project is the demonstration of the carbonate fuel cell technology at full scale. Additional objectives of the project include the demonstration of specific advantages of the direct carbonate fuel cell power plant, such as high efficiency, low emissions, reactive power capability, and high reliability and availability. The project will also provide design input for precommercial early production power plants.

  11. High Performance Fortran: An overview

    SciTech Connect

    Zosel, M.E.

    1992-12-23

    The purpose of this paper is to give an overview of the work of the High Performance Fortran Forum (HPFF). This group of industry, academic, and user representatives has been meeting to define a set of extensions for Fortran dedicated to the special problems posed by a very high performance computers, especially the new generation of parallel computers. The paper describes the HPFF effort and its goals and gives a brief description of the functionality of High Performance Fortran (HPF).

  12. Guidelines for design and development of industrially relevant MCFC stacks

    SciTech Connect

    Torazza, A.; Dufour, A.; Giorgi, L.

    1996-12-31

    An interesting way of reducing the production costs of the electrical energy by improving efficiency and, at the same time, having a good integration between environment and power plants is offered by the utilization of the fuel cells operating at high temperatures. From this point of view, Molten Carbonate Fuel Cells (MCFCs) seem to be one of the most promising technologies because of their environmental friendly operation for various fuels and potential low cost. In fact it is well known that the MCFCs overall plant efficiency is typically some 500% and can reach, as a consequence of their high operating temperature, 65% with a bottoming cycle. Moreover MCFCs will be particularly attractive for dispersed power plants of MW size located at user sites. Additional advantages of MCFCs are their good response to base and partial load, short time for plant erection and modularity.

  13. High Performance Thin Layer Chromatography.

    ERIC Educational Resources Information Center

    Costanzo, Samuel J.

    1984-01-01

    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  14. High Performance Flexible Thermal Link

    NASA Astrophysics Data System (ADS)

    Sauer, Arne; Preller, Fabian

    2014-06-01

    The paper deals with the design and performance verification of a high performance and flexible carbon fibre thermal link.Project goal was to design a space qualified thermal link combining low mass, flexibility and high thermal conductivity with new approaches regarding selected materials and processes. The idea was to combine the advantages of existing metallic links regarding flexibility and the thermal performance of high conductive carbon pitch fibres. Special focus is laid on the thermal performance improvement of matrix systems by means of nano-scaled carbon materials in order to improve the thermal performance also perpendicular to the direction of the unidirectional fibres.One of the main challenges was to establish a manufacturing process which allows handling the stiff and brittle fibres, applying the matrix and performing the implementation into an interface component using unconventional process steps like thermal bonding of fibres after metallisation.This research was funded by the German Federal Ministry for Economic Affairs and Energy (BMWi).

  15. High Performance Networks for High Impact Science

    SciTech Connect

    Scott, Mary A.; Bair, Raymond A.

    2003-02-13

    This workshop was the first major activity in developing a strategic plan for high-performance networking in the Office of Science. Held August 13 through 15, 2002, it brought together a selection of end users, especially representing the emerging, high-visibility initiatives, and network visionaries to identify opportunities and begin defining the path forward.

  16. Catalyzed double layer cathodes for high performance and long life molten carbonate fuel cells

    SciTech Connect

    Bischoff, M.; Jantsch, U.; Rohland, B.

    1996-12-31

    NiO/LiCoO{sub 2} double layer cathodes (DLCs) were prepared with a thin highly active LiCoO{sub 2}-layer by a new double layer tape casting/sintering procedure. The resulting metallic porous precursor plates were mounted into the MCFC and heated up by a special procedure to form LiCoO{sub 2} from air, Co and Li{sub 2}CO{sub 3} in a solid/gas reaction. MCFCs with highly active NiO/LiCoO{sub 2}-DLCs can operate over prolonged periods of time with a Ni-precipitation which is 10% lower than one finds with state of the art NiO cathodes. According to LiCoO{sub 2}-cathodes have theoretical life times of more than 100 000 hours at nonpressurized conditions. MCFCs with new NiO/LiCoO{sub 2} double layer cathodes (DLC) were investigated with regard to variable parameters of their microstructure. From the agglomerate model of the porous MCFC cathode, the dependence of the polarization resistance from the radius of the agglomerates and the inner agglomerate surface area was calculated.

  17. High-Performance Liquid Chromatography

    NASA Astrophysics Data System (ADS)

    Reuhs, Bradley L.; Rounds, Mary Ann

    High-performance liquid chromatography (HPLC) developed during the 1960s as a direct offshoot of classic column liquid chromatography through improvements in the technology of columns and instrumental components (pumps, injection valves, and detectors). Originally, HPLC was the acronym for high-pressure liquid chromatography, reflecting the high operating pressures generated by early columns. By the late 1970s, however, high-performance liquid chromatography had become the preferred term, emphasizing the effective separations achieved. In fact, newer columns and packing materials offer high performance at moderate pressure (although still high pressure relative to gravity-flow liquid chromatography). HPLC can be applied to the analysis of any compound with solubility in a liquid that can be used as the mobile phase. Although most frequently employed as an analytical technique, HPLC also may be used in the preparative mode.

  18. Multilayer high performance insulation materials

    NASA Technical Reports Server (NTRS)

    Stuckey, J. M.

    1971-01-01

    A number of tests are required to evaluate both multilayer high performance insulation samples and the materials that comprise them. Some of the techniques and tests being employed for these evaluations and some of the results obtained from thermal conductivity tests, outgassing studies, effect of pressure on layer density tests, hypervelocity impact tests, and a multilayer high performance insulation ambient storage program at the Kennedy Space Center are presented.

  19. High performance flexible heat pipes

    NASA Technical Reports Server (NTRS)

    Shaubach, R. M.; Gernert, N. J.

    1985-01-01

    A Phase I SBIR NASA program for developing and demonstrating high-performance flexible heat pipes for use in the thermal management of spacecraft is examined. The program combines several technologies such as flexible screen arteries and high-performance circumferential distribution wicks within an envelope which is flexible in the adiabatic heat transport zone. The first six months of work during which the Phase I contract goal were met, are described. Consideration is given to the heat-pipe performance requirements. A preliminary evaluation shows that the power requirement for Phase II of the program is 30.5 kilowatt meters at an operating temperature from 0 to 100 C.

  20. High performance dielectric materials development

    NASA Astrophysics Data System (ADS)

    Piche, Joe; Kirchner, Ted; Jayaraj, K.

    1994-09-01

    The mission of polymer composites materials technology is to develop materials and processing technology to meet DoD and commercial needs. The following are outlined in this presentation: high performance capacitors, high temperature aerospace insulation, rationale for choosing Foster-Miller (the reporting industry), the approach to the development and evaluation of high temperature insulation materials, and the requirements/evaluation parameters. Supporting tables and diagrams are included.

  1. High performance dielectric materials development

    NASA Technical Reports Server (NTRS)

    Piche, Joe; Kirchner, Ted; Jayaraj, K.

    1994-01-01

    The mission of polymer composites materials technology is to develop materials and processing technology to meet DoD and commercial needs. The following are outlined in this presentation: high performance capacitors, high temperature aerospace insulation, rationale for choosing Foster-Miller (the reporting industry), the approach to the development and evaluation of high temperature insulation materials, and the requirements/evaluation parameters. Supporting tables and diagrams are included.

  2. A preliminary design and BOP cost analysis of M-C Power`s MCFC commerical unit

    SciTech Connect

    Chen, T.P.

    1996-12-31

    M-C Power Corporation plans to introduce its molten carbonate fuel cell (MCFC) market entry unit in the year 2000 for distributed and on-site power generation. Extensive efforts have been made to analyze the cell stack manufacturing costs. The major objective of this study is to conduct a detailed analysis of BOP costs based on an initial design of the market entry unit.

  3. INL High Performance Building Strategy

    SciTech Connect

    Jennifer D. Morton

    2010-02-01

    High performance buildings, also known as sustainable buildings and green buildings, are resource efficient structures that minimize the impact on the environment by using less energy and water, reduce solid waste and pollutants, and limit the depletion of natural resources while also providing a thermally and visually comfortable working environment that increases productivity for building occupants. As Idaho National Laboratory (INL) becomes the nation’s premier nuclear energy research laboratory, the physical infrastructure will be established to help accomplish this mission. This infrastructure, particularly the buildings, should incorporate high performance sustainable design features in order to be environmentally responsible and reflect an image of progressiveness and innovation to the public and prospective employees. Additionally, INL is a large consumer of energy that contributes to both carbon emissions and resource inefficiency. In the current climate of rising energy prices and political pressure for carbon reduction, this guide will help new construction project teams to design facilities that are sustainable and reduce energy costs, thereby reducing carbon emissions. With these concerns in mind, the recommendations described in the INL High Performance Building Strategy (previously called the INL Green Building Strategy) are intended to form the INL foundation for high performance building standards. This revised strategy incorporates the latest federal and DOE orders (Executive Order [EO] 13514, “Federal Leadership in Environmental, Energy, and Economic Performance” [2009], EO 13423, “Strengthening Federal Environmental, Energy, and Transportation Management” [2007], and DOE Order 430.2B, “Departmental Energy, Renewable Energy, and Transportation Management” [2008]), the latest guidelines, trends, and observations in high performance building construction, and the latest changes to the Leadership in Energy and Environmental Design

  4. Operating experience with a 250 kW el molten carbonate fuel cell (MCFC) power plant

    NASA Astrophysics Data System (ADS)

    Bischoff, Manfred; Huppmann, Gerhard

    The MTU MCFC program is carried out by a European consortium comprising the German companies MTU Friedrichshafen GmbH, Ruhrgas AG and RWE Energie AG as well as the Danish company Energi E2 S/A. MTU acts as consortium leader. The company shares a license and technology exchange agreement with Fuel Cell Energy Inc., Danbury, CT, USA (formerly Energy Research Corp., ERC). The program was started in 1990 and covers a period of about 10 years. The highlights of this program to date are: Considerable improvements regarding component stability have been demonstrated on laboratory scale. Manufacturing technology has been developed to a point which enables the consortium to fabricate the porous components on a 250 cm 2 scale. Several large area stacks with 5000-7660 cm 2 cell area and a power range of 3-10 kW have been tested at the facilities in Munich (Germany) and Kyndby (Denmark). These stacks have been supplied by FCE. As far as the system design is concerned it was soon realized that conventional systems do not hold the promise for competitive power plants. A system analysis led to the conclusion that a new innovative design approach is required. As a result the "Hot Module" system was developed by the consortium. A Hot Module combines all the components of a MCFC system operating at the similar temperatures and pressures into a common thermally insulated vessel. In August 1997 the consortium started its first full size Hot Module MCFC test plant at the facilities of Ruhrgas AG in Dorsten, Germany. The stack was assembled in Munich using 292 cell packages purchased from FCE. The plant is based on the consortium's unique and proprietary "Hot Module" concept. It operates on pipeline natural gas and was grid connected on 16 August 1997. After a total of 1500 h of operation, the plant was intentionally shut down in a controlled manner in April 1998 for post-test analysis. The Hot Module system concept has demonstrated its functionality. The safety concept has been

  5. High Performance Bulk Thermoelectric Materials

    SciTech Connect

    Ren, Zhifeng

    2013-03-31

    Over 13 plus years, we have carried out research on electron pairing symmetry of superconductors, growth and their field emission property studies on carbon nanotubes and semiconducting nanowires, high performance thermoelectric materials and other interesting materials. As a result of the research, we have published 104 papers, have educated six undergraduate students, twenty graduate students, nine postdocs, nine visitors, and one technician.

  6. High performance bilateral telerobot control.

    PubMed

    Kline-Schoder, Robert; Finger, William; Hogan, Neville

    2002-01-01

    Telerobotic systems are used when the environment that requires manipulation is not easily accessible to humans, as in space, remote, hazardous, or microscopic applications or to extend the capabilities of an operator by scaling motions and forces. The Creare control algorithm and software is an enabling technology that makes possible guaranteed stability and high performance for force-feedback telerobots. We have developed the necessary theory, structure, and software design required to implement high performance telerobot systems with time delay. This includes controllers for the master and slave manipulators, the manipulator servo levels, the communication link, and impedance shaping modules. We verified the performance using both bench top hardware as well as a commercial microsurgery system.

  7. High Performance Tools And Technologies

    SciTech Connect

    Collette, M R; Corey, I R; Johnson, J R

    2005-01-24

    This goal of this project was to evaluate the capability and limits of current scientific simulation development tools and technologies with specific focus on their suitability for use with the next generation of scientific parallel applications and High Performance Computing (HPC) platforms. The opinions expressed in this document are those of the authors, and reflect the authors' current understanding and functionality of the many tools investigated. As a deliverable for this effort, we are presenting this report describing our findings along with an associated spreadsheet outlining current capabilities and characteristics of leading and emerging tools in the high performance computing arena. This first chapter summarizes our findings (which are detailed in the other chapters) and presents our conclusions, remarks, and anticipations for the future. In the second chapter, we detail how various teams in our local high performance community utilize HPC tools and technologies, and mention some common concerns they have about them. In the third chapter, we review the platforms currently or potentially available to utilize these tools and technologies on to help in software development. Subsequent chapters attempt to provide an exhaustive overview of the available parallel software development tools and technologies, including their strong and weak points and future concerns. We categorize them as debuggers, memory checkers, performance analysis tools, communication libraries, data visualization programs, and other parallel development aides. The last chapter contains our closing information. Included with this paper at the end is a table of the discussed development tools and their operational environment.

  8. High performance pyroelectric infrared detector

    NASA Astrophysics Data System (ADS)

    Hu, Xu; Luo, Haosu; Ji, Yulong; Yang, Chunli

    2015-10-01

    Single infrared detector made with Relaxative ferroelectric crystal(PMNT) present excellence performance. In this paper include detector capacitance, characteristic of frequency--response, characteristic of detectivity. The measure result show that detectivity of detector made with relaxative ferroelectric crystal(PMNT) exceed three times than made with LT, the D*achieved than 1*109cmHz0.5W-1. The detector will be applied on NDIR spectrograph, FFT spectrograph and so on. The high performance pyroelectric infrared detector be developed that will be broadened application area of infrared detector.

  9. Toward high performance graphene fibers.

    PubMed

    Chen, Li; He, Yuling; Chai, Songgang; Qiang, Hong; Chen, Feng; Fu, Qiang

    2013-07-07

    Two-dimensional graphene and graphene-based materials have attracted tremendous interest, hence much attention has been drawn to exploring and applying their exceptional characteristics and properties. Integration of graphene sheets into macroscopic fibers is a very important way for their application and has received increasing interest. In this study, neat and macroscopic graphene fibers were continuously spun from graphene oxide (GO) suspensions followed by chemical reduction. By varying wet-spinning conditions, a series of graphene fibers were prepared, then, the structural features, mechanical and electrical performances of the fibers were investigated. We found the orientation of graphene sheets, the interaction between inter-fiber graphene sheets and the defects in the fibers have a pronounced effect on the properties of the fibers. Graphene fibers with excellent mechanical and electrical properties will yield great advances in high-tech applications. These findings provide guidance for the future production of high performance graphene fibers.

  10. High performance ammonium nitrate propellant

    NASA Technical Reports Server (NTRS)

    Anderson, F. A. (Inventor)

    1979-01-01

    A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine.

  11. High-performance sports medicine.

    PubMed

    Speed, Cathy

    2013-02-01

    High performance sports medicine involves the medical care of athletes, who are extraordinary individuals and who are exposed to intensive physical and psychological stresses during training and competition. The physician has a broad remit and acts as a 'medical guardian' to optimise health while minimising risks. This review describes this interesting field of medicine, its unique challenges and priorities for the physician in delivering best healthcare.

  12. Reduced Toxicity High Performance Monopropellant

    DTIC Science & Technology

    2011-09-01

    distribution unlimited Propellant Performance Characteristics LMP - 103S AF-M315E Hydrazine Flame Temperature 1600ºC 1900ºC 600 oC Isp 252 (theor)235 sec...public release; distribution unlimited Compatibility and Handling Propellant LMP - 103S AF-M315E Thruster Materials Compatibility High combustion...detonation Bikini gauges indicate > 103 kPa @ 50ft Fragments thrown > 185 m Punched hole in end cap 12 Distribution A: Approved for public

  13. High-performance permanent magnets.

    PubMed

    Goll, D; Kronmüller, H

    2000-10-01

    High-performance permanent magnets (pms) are based on compounds with outstanding intrinsic magnetic properties as well as on optimized microstructures and alloy compositions. The most powerful pm materials at present are RE-TM intermetallic alloys which derive their exceptional magnetic properties from the favourable combination of rare earth metals (RE = Nd, Pr, Sm) with transition metals (TM = Fe, Co), in particular magnets based on (Nd.Pr)2Fe14B and Sm2(Co,Cu,Fe,Zr)17. Their development during the last 20 years has involved a dramatic improvement in their performance by a factor of > 15 compared with conventional ferrite pms therefore contributing positively to the ever-increasing demand for pms in many (including new) application fields, to the extent that RE-TM pms now account for nearly half of the worldwide market. This review article first gives a brief introduction to the basics of ferromagnetism to confer an insight into the variety of (permanent) magnets, their manufacture and application fields. We then examine the rather complex relationship between the microstructure and the magnetic properties for the two highest-performance and most promising pm materials mentioned. By using numerical micromagnetic simulations on the basis of the Finite Element technique the correlation can be quantitatively predicted, thus providing a powerful tool for the further development of optimized high-performance pms.

  14. High-performance permanent magnets

    NASA Astrophysics Data System (ADS)

    Goll, D.; Kronmüller, H.

    High-performance permanent magnets (pms) are based on compounds with outstanding intrinsic magnetic properties as well as on optimized microstructures and alloy compositions. The most powerful pm materials at present are RE-TM intermetallic alloys which derive their exceptional magnetic properties from the favourable combination of rare earth metals (RE=Nd, Pr, Sm) with transition metals (TM=Fe, Co), in particular magnets based on (Nd,Pr)2Fe14B and Sm2(Co,Cu,Fe,Zr)17. Their development during the last 20 years has involved a dramatic improvement in their performance by a factor of >15 compared with conventional ferrite pms therefore contributing positively to the ever-increasing demand for pms in many (including new) application fields, to the extent that RE-TM pms now account for nearly half of the worldwide market. This review article first gives a brief introduction to the basics of ferromagnetism to confer an insight into the variety of (permanent) magnets, their manufacture and application fields. We then examine the rather complex relationship between the microstructure and the magnetic properties for the two highest-performance and most promising pm materials mentioned. By using numerical micromagnetic simulations on the basis of the Finite Element technique the correlation can be quantitatively predicted, thus providing a powerful tool for the further development of optimized high-performance pms.

  15. Status of the M-C Power IMHEX{reg_sign} MCFC commercialization program

    SciTech Connect

    Laurens, R.M.; Scroppo, J.A.; Petri, R.J.; Benjamin, T.G.

    1996-12-31

    Six years ago, M-C Power (MCP) developed a comprehensive business plan to commercialize molten carbonate fuel cell (MCFC) power plants. On an annual basis the plan has been reviewed and modified to adapt to identified end user needs and technological advancements. As a result, product definition kept abreast with marketing requirements. Over the last five years, there was order and reason for subtle shifts in supply, demand, competition and pricing policies. Today, however, traditional market assessment assumptions must be challenged. There is a revolution taking place. The revolution can be summed up in one word ... deregulation. Deregulation of the airline industry led to consideration of the natural gas industry. Now that natural gas deregulation is behind us, it is electric power and telecommunications that are receiving attention. Increased emphasis is being placed on achieving market-priced power. The net result will be thinner margins for the seller and the end user. What does this mean for the commercialization of molten carbonate fuel cells?

  16. Factor Study for the Separator Plate of Mcfc Having Uniform Stiffness at Elevated Temperature

    NASA Astrophysics Data System (ADS)

    Lee, Sang-Wook; Kim, Jung-Hyun; Jun, Joong-Hwan

    A molten carbonate fuel cell (MCFC) is composed of several stacks of unit cells. A unit cell is composed of two electrodes and a matrix that is inserted between separator plates. Separator plates should properly contact the electrodes to reduce the electricity loss arising from contact resistance. To this end, a pressure of about 2 kgf/cm2 is usually applied on the top of the stack, which results in the separator plates being somewhat compacted. Furthermore, the stiffness of the separator plates becomes degraded at elevated temperatures due to softening of the plate materials. Therefore, a nonuniform temperature distribution across the separator plates induced by exothermic reactions of the oxidant and reactant gases leads to a non-uniform plate stiffness. This study has firstly evaluated the change in separator plate stiffness as temperature changes by applying pressure to the plates. Secondly, using the Taguchi method, several design factors that affect stiffness have been investigated to determine which has the most influence. Based on these results, a new design for the separators, which allows for uniform stiffness at elevated temperatures, has been proposed.

  17. High Performance Parallel Computational Nanotechnology

    NASA Technical Reports Server (NTRS)

    Saini, Subhash; Craw, James M. (Technical Monitor)

    1995-01-01

    At a recent press conference, NASA Administrator Dan Goldin encouraged NASA Ames Research Center to take a lead role in promoting research and development of advanced, high-performance computer technology, including nanotechnology. Manufacturers of leading-edge microprocessors currently perform large-scale simulations in the design and verification of semiconductor devices and microprocessors. Recently, the need for this intensive simulation and modeling analysis has greatly increased, due in part to the ever-increasing complexity of these devices, as well as the lessons of experiences such as the Pentium fiasco. Simulation, modeling, testing, and validation will be even more important for designing molecular computers because of the complex specification of millions of atoms, thousands of assembly steps, as well as the simulation and modeling needed to ensure reliable, robust and efficient fabrication of the molecular devices. The software for this capacity does not exist today, but it can be extrapolated from the software currently used in molecular modeling for other applications: semi-empirical methods, ab initio methods, self-consistent field methods, Hartree-Fock methods, molecular mechanics; and simulation methods for diamondoid structures. In as much as it seems clear that the application of such methods in nanotechnology will require powerful, highly powerful systems, this talk will discuss techniques and issues for performing these types of computations on parallel systems. We will describe system design issues (memory, I/O, mass storage, operating system requirements, special user interface issues, interconnects, bandwidths, and programming languages) involved in parallel methods for scalable classical, semiclassical, quantum, molecular mechanics, and continuum models; molecular nanotechnology computer-aided designs (NanoCAD) techniques; visualization using virtual reality techniques of structural models and assembly sequences; software required to

  18. High Performance Pulse Tube Cryocoolers

    NASA Astrophysics Data System (ADS)

    Olson, J. R.; Roth, E.; Champagne, P.; Evtimov, B.; Nast, T. C.

    2008-03-01

    Lockheed Martin's Advanced Technology Center has been developing pulse tube cryocoolers for more than ten years. Recent innovations include successful testing of four-stage coldheads, no-load temperature below 4 K, and the recent development of a high-efficiency compressor. This paper discusses the predicted performance of single and multiple stage pulse tube coldheads driven by our new 6 kg "M5Midi" compressor, which is capable of 90% efficiency with 200 W input power, and a maximum input power of 1000 W. This compressor retains the simplicity of earlier LM-ATC compressors: it has a moving magnet and an external electrical coil, minimizing organics in the working gas and requiring no electrical penetrations through the pressure wall. Motor losses were minimized during design, resulting in a simple, easily-manufactured compressor with state-of-the-art motor efficiency. The predicted cryocooler performance is presented as simple formulae, allowing an engineer to include the impact of a highly-optimized cryocooler into a full system analysis. Performance is given as a function of the heat rejection temperature and the cold tip temperatures and cooling loads.

  19. High performance aerated lagoon systems

    SciTech Connect

    Rich, L.

    1999-08-01

    At a time when less money is available for wastewater treatment facilities and there is increased competition for the local tax dollar, regulatory agencies are enforcing stricter effluent limits on treatment discharges. A solution for both municipalities and industry is to use aerated lagoon systems designed to meet these limits. This monograph, prepared by a recognized expert in the field, provides methods for the rational design of a wide variety of high-performance aerated lagoon systems. Such systems range from those that can be depended upon to meet secondary treatment standards alone to those that, with the inclusion of intermittent sand filters or elements of sequenced biological reactor (SBR) technology, can also provide for nitrification and nutrient removal. Considerable emphasis is placed on the use of appropriate performance parameters, and an entire chapter is devoted to diagnosing performance failures. Contents include: principles of microbiological processes, control of algae, benthal stabilization, design for CBOD removal, design for nitrification and denitrification in suspended-growth systems, design for nitrification in attached-growth systems, phosphorus removal, diagnosing performance.

  20. High Performance Proactive Digital Forensics

    NASA Astrophysics Data System (ADS)

    Alharbi, Soltan; Moa, Belaid; Weber-Jahnke, Jens; Traore, Issa

    2012-10-01

    With the increase in the number of digital crimes and in their sophistication, High Performance Computing (HPC) is becoming a must in Digital Forensics (DF). According to the FBI annual report, the size of data processed during the 2010 fiscal year reached 3,086 TB (compared to 2,334 TB in 2009) and the number of agencies that requested Regional Computer Forensics Laboratory assistance increasing from 689 in 2009 to 722 in 2010. Since most investigation tools are both I/O and CPU bound, the next-generation DF tools are required to be distributed and offer HPC capabilities. The need for HPC is even more evident in investigating crimes on clouds or when proactive DF analysis and on-site investigation, requiring semi-real time processing, are performed. Although overcoming the performance challenge is a major goal in DF, as far as we know, there is almost no research on HPC-DF except for few papers. As such, in this work, we extend our work on the need of a proactive system and present a high performance automated proactive digital forensic system. The most expensive phase of the system, namely proactive analysis and detection, uses a parallel extension of the iterative z algorithm. It also implements new parallel information-based outlier detection algorithms to proactively and forensically handle suspicious activities. To analyse a large number of targets and events and continuously do so (to capture the dynamics of the system), we rely on a multi-resolution approach to explore the digital forensic space. Data set from the Honeynet Forensic Challenge in 2001 is used to evaluate the system from DF and HPC perspectives.

  1. HIGH PERFORMANCE EBIS FOR RHIC.

    SciTech Connect

    ALESSI,J.; BEEBE, E.; GOULD, O.; KPONOU, A.; LOCKEY, R.; PIKIN, A.; RAPARIA, D.; RITTER, J.; SNYDSTRUP, L.

    2007-06-25

    An Electron Beam Ion Source (EBIS), capable of producing high charge states and high beam currents of any heavy ion species in short pulses, is ideally suited for injection into a synchrotron. An EBIS-based, high current, heavy ion preinjector is now being built at Brookhaven to provide increased capabilities for the Relativistic Heavy Ion Collider (RHIC), and the NASA Space Radiation Laboratory (NSRL). Benefits of the new preinjector include the ability to produce ions of any species, fast switching between species to serve the simultaneous needs of multiple programs, and lower operating and maintenance costs. A state-of-the-art EBIS, operating with an electron beam current of up to 10 A, and producing multi-milliamperes of high charge state heavy ions, has been developed at Brookhaven, and has been operating very successfully on a test bench for several years. The present performance of this high-current EBIS is presented, along with details of the design of the scaled-up EBIS for RHIC, and the status of its construction. Other aspects of the project, including design and construction of the heavy ion RFQ, Linac, and matching beamlines, are also mentioned.

  2. The High Performance Storage System

    SciTech Connect

    Coyne, R.A.; Hulen, H.; Watson, R.

    1993-09-01

    The National Storage Laboratory (NSL) was organized to develop, demonstrate and commercialize technology for the storage system that will be the future repositories for our national information assets. Within the NSL four Department of Energy laboratories and IBM Federal System Company have pooled their resources to develop an entirely new High Performance Storage System (HPSS). The HPSS project concentrates on scalable parallel storage system for highly parallel computers as well as traditional supercomputers and workstation clusters. Concentrating on meeting the high end of storage system and data management requirements, HPSS is designed using network-connected storage devices to transfer data at rates of 100 million bytes per second and beyond. The resulting products will be portable to many vendor`s platforms. The three year project is targeted to be complete in 1995. This paper provides an overview of the requirements, design issues, and architecture of HPSS, as well as a description of the distributed, multi-organization industry and national laboratory HPSS project.

  3. High Performance Perovskite Solar Cells.

    PubMed

    Tong, Xin; Lin, Feng; Wu, Jiang; Wang, Zhiming M

    2016-05-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long-term stable all-solid-state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost-effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole-transporting materials (HTMs) and electron-transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction.

  4. High performance phenolic pultrusion resin

    SciTech Connect

    Qureshi, S.P.; Ingram, W.H.; Smith, C.

    1996-11-01

    Today, Phenol-Formaldehyde (PF) resins are the materials of choice for aerospace interior applications, primarily due to low FST (flame, smoke and toxicity). Since 1990, growth of PF resins has been steadily increasing in non-aerospace applications (which include mass transit, construction, marine, mine ducting and offshore oil) due to low FST and reasonable cost. This paper describes one component phenol-formaldehyde resin that was jointly developed with Morrison Molded Fiber Glass for their pultrusion process. Physical properties of the resin with flame/smoke/toxicity, chemical resistance and mechanical performance of the pultruded RP are discussed. Neat resin screening tests to identify high-temperature formulations are explored. Research continues at Georgia-Pacific to investigate the effect of formulation variables on processing and mechanical properties.

  5. High Performance Perovskite Solar Cells

    PubMed Central

    Tong, Xin; Lin, Feng; Wu, Jiang

    2015-01-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long‐term stable all‐solid‐state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost‐effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole‐transporting materials (HTMs) and electron‐transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction. PMID:27774402

  6. High performance Cu adhesion coating

    SciTech Connect

    Lee, K.W.; Viehbeck, A.; Chen, W.R.; Ree, M.

    1996-12-31

    Poly(arylene ether benzimidazole) (PAEBI) is a high performance thermoplastic polymer with imidazole functional groups forming the polymer backbone structure. It is proposed that upon coating PAEBI onto a copper surface the imidazole groups of PAEBI form a bond with or chelate to the copper surface resulting in strong adhesion between the copper and polymer. Adhesion of PAEBI to other polymers such as poly(biphenyl dianhydride-p-phenylene diamine) (BPDA-PDA) polyimide is also quite good and stable. The resulting locus of failure as studied by XPS and IR indicates that PAEBI gives strong cohesive adhesion to copper. Due to its good adhesion and mechanical properties, PAEBI can be used in fabricating thin film semiconductor packages such as multichip module dielectric (MCM-D) structures. In these applications, a thin PAEBI coating is applied directly to a wiring layer for enhancing adhesion to both the copper wiring and the polymer dielectric surface. In addition, a thin layer of PAEBI can also function as a protection layer for the copper wiring, eliminating the need for Cr or Ni barrier metallurgies and thus significantly reducing the number of process steps.

  7. ALMA high performance nutating subreflector

    NASA Astrophysics Data System (ADS)

    Gasho, Victor L.; Radford, Simon J. E.; Kingsley, Jeffrey S.

    2003-02-01

    For the international ALMA project"s prototype antennas, we have developed a high performance, reactionless nutating subreflector (chopping secondary mirror). This single axis mechanism can switch the antenna"s optical axis by +/-1.5" within 10 ms or +/-5" within 20 ms and maintains pointing stability within the antenna"s 0.6" error budget. The light weight 75 cm diameter subreflector is made of carbon fiber composite to achieve a low moment of inertia, <0.25 kg m2. Its reflecting surface was formed in a compression mold. Carbon fiber is also used together with Invar in the supporting structure for thermal stability. Both the subreflector and the moving coil motors are mounted on flex pivots and the motor magnets counter rotate to absorb the nutation reaction force. Auxiliary motors provide active damping of external disturbances, such as wind gusts. Non contacting optical sensors measure the positions of the subreflector and the motor rocker. The principle mechanical resonance around 20 Hz is compensated with a digital PID servo loop that provides a closed loop bandwidth near 100 Hz. Shaped transitions are used to avoid overstressing mechanical links.

  8. High Performance Torso Cooling Garment

    NASA Technical Reports Server (NTRS)

    Conger, Bruce

    2016-01-01

    The concept proposed in this paper is to improve thermal efficiencies of the liquid cooling and ventilation garment (LCVG) in the torso area, which could facilitate removal of LCVG tubing from the arms and legs, thereby increasing suited crew member mobility. EVA space suit mobility in micro-gravity is challenging, and it becomes even more challenging in the gravity of Mars. By using shaped water tubes that greatly increase the contact area with the skin in the torso region of the body, the heat transfer efficiency can be increased. This increase in efficiency could provide the required liquid cooling via torso tubing only; no arm or leg LCVG tubing would be required. Benefits of this approach include increased crewmember mobility, reduced LCVG mass, enhanced evaporation cooling, increased comfort during Mars EVA tasks, and easing of the overly dry condition in the helmet associated with the Advanced Extravehicular Mobility Unit (EMU) ventilation loop currently under development. This report describes analysis and test activities performed to evaluate the potential improvements to the thermal performance of the LCVG. Analyses evaluated potential tube shapes for improving the thermal performance of the LCVG. The analysis results fed into the selection of flat flow strips to improve thermal contact with the skin of the suited test subject. Testing of small segments was performed to compare thermal performance of the tubing approach of the current LCVG to the flat flow strips proposed as the new concept. Results of the testing is presented along with recommendations for future development of this new concept.

  9. High Performance Torso Cooling Garment

    NASA Technical Reports Server (NTRS)

    Conger, Bruce; Makinen, Janice

    2016-01-01

    The concept proposed in this paper is to improve thermal efficiencies of the liquid cooling and ventilation garment (LCVG) in the torso area, which could facilitate removal of LCVG tubing from the arms and legs, thereby increasing suited crew member mobility. EVA space suit mobility in micro-gravity is challenging, and it becomes even more challenging in the gravity of Mars. By using shaped water tubes that greatly increase the contact area with the skin in the torso region of the body, the heat transfer efficiency can be increased. This increase in efficiency could provide the required liquid cooling via torso tubing only; no arm or leg LCVG tubing would be required. Benefits of this approach include increased crewmember mobility, enhanced evaporation cooling, increased comfort during Mars EVA tasks, and easing of the overly dry condition in the helmet associated with the Advanced Extravehicular Mobility Unit (EMU) ventilation loop currently under development. This report describes analysis and test activities performed to evaluate the potential improvements to the thermal performance of the LCVG. Analyses evaluated potential tube shapes for improving the thermal performance of the LCVG. The analysis results fed into the selection of flat flow strips to improve thermal contact with the skin of the suited test subject. Testing of small segments was performed to compare thermal performance of the tubing approach of the current LCVG to the flat flow strips proposed as the new concept. Results of the testing is presented along with recommendations for future development of this new concept.

  10. Indoor Air Quality in High Performance Schools

    EPA Pesticide Factsheets

    High performance schools are facilities that improve the learning environment while saving energy, resources, and money. The key is understanding the lifetime value of high performance schools and effectively managing priorities, time, and budget.

  11. A high performance thermoacoustic engine

    NASA Astrophysics Data System (ADS)

    Tijani, M. E. H.; Spoelstra, S.

    2011-11-01

    In thermoacoustic systems heat is converted into acoustic energy and vice versa. These systems use inert gases as working medium and have no moving parts which makes the thermoacoustic technology a serious alternative to produce mechanical or electrical power, cooling power, and heating in a sustainable and environmentally friendly way. A thermoacoustic Stirling heat engine is designed and built which achieves a record performance of 49% of the Carnot efficiency. The design and performance of the engine is presented. The engine has no moving parts and is made up of few simple components.

  12. High-performance composite chocolate

    NASA Astrophysics Data System (ADS)

    Dean, Julian; Thomson, Katrin; Hollands, Lisa; Bates, Joanna; Carter, Melvyn; Freeman, Colin; Kapranos, Plato; Goodall, Russell

    2013-07-01

    The performance of any engineering component depends on and is limited by the properties of the material from which it is fabricated. It is crucial for engineering students to understand these material properties, interpret them and select the right material for the right application. In this paper we present a new method to engage students with the material selection process. In a competition-based practical, first-year undergraduate students design, cost and cast composite chocolate samples to maximize a particular performance criterion. The same activity could be adapted for any level of education to introduce the subject of materials properties and their effects on the material chosen for specific applications.

  13. High-Performance Composite Chocolate

    ERIC Educational Resources Information Center

    Dean, Julian; Thomson, Katrin; Hollands, Lisa; Bates, Joanna; Carter, Melvyn; Freeman, Colin; Kapranos, Plato; Goodall, Russell

    2013-01-01

    The performance of any engineering component depends on and is limited by the properties of the material from which it is fabricated. It is crucial for engineering students to understand these material properties, interpret them and select the right material for the right application. In this paper we present a new method to engage students with…

  14. Toward High-Performance Organizations.

    ERIC Educational Resources Information Center

    Lawler, Edward E., III

    2002-01-01

    Reviews management changes that companies have made over time in adopting or adapting four approaches to organizational performance: employee involvement, total quality management, re-engineering, and knowledge management. Considers future possibilities and defines a new view of what constitutes effective organizational design in management.…

  15. Sustaining High Performance in Bad Times.

    ERIC Educational Resources Information Center

    Bassi, Laurie J.; Van Buren, Mark A.

    1997-01-01

    Summarizes the results of the American Society for Training and Development Human Resource and Performance Management Survey of 1996 that examined the performance outcomes of downsizing and high performance work systems, explored the relationship between high performance work systems and downsizing, and asked whether some downsizing practices were…

  16. High performance, high density hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Frankenfeld, J. W.; Hastings, T. W.; Lieberman, M.; Taylor, W. F.

    1978-01-01

    The fuels were selected from 77 original candidates on the basis of estimated merit index and cost effectiveness. The ten candidates consisted of 3 pure compounds, 4 chemical plant streams and 3 refinery streams. Critical physical and chemical properties of the candidate fuels were measured including heat of combustion, density, and viscosity as a function of temperature, freezing points, vapor pressure, boiling point, thermal stability. The best all around candidate was found to be a chemical plant olefin stream rich in dicyclopentadiene. This material has a high merit index and is available at low cost. Possible problem areas were identified as low temperature flow properties and thermal stability. An economic analysis was carried out to determine the production costs of top candidates. The chemical plant and refinery streams were all less than 44 cent/kg while the pure compounds were greater than 44 cent/kg. A literature survey was conducted on the state of the art of advanced hydrocarbon fuel technology as applied to high energy propellents. Several areas for additional research were identified.

  17. Nanocrystalline high performance permanent magnets

    NASA Astrophysics Data System (ADS)

    Gutfleisch, O.; Bollero, A.; Handstein, A.; Hinz, D.; Kirchner, A.; Yan, A.; Müller, K.-H.; Schultz, L.

    2002-04-01

    Recent developments in nanocrystalline rare earth-transition metal magnets are reviewed and emphasis is placed on research work at IFW Dresden. Principal synthesis methods include high energy ball milling, melt spinning and hydrogen assisted methods such as reactive milling and hydrogenation-disproportionation-desorption-recombination. These techniques are applied to NdFeB-, PrFeB- and SmCo-type systems with the aim to produce high remanence magnets with high coercivity. Concepts of maximizing the energy density in nanostructured magnets by either inducing a texture via anisotropic HDDR or hot deformation or enhancing the remanence via magnetic exchange coupling are evaluated.

  18. Carpet Aids Learning in High Performance Schools

    ERIC Educational Resources Information Center

    Hurd, Frank

    2009-01-01

    The Healthy and High Performance Schools Act of 2002 has set specific federal guidelines for school design, and developed a federal/state partnership program to assist local districts in their school planning. According to the Collaborative for High Performance Schools (CHPS), high-performance schools are, among other things, healthy, comfortable,…

  19. High-Performance Miniature Hygrometer

    NASA Technical Reports Server (NTRS)

    Van Zandt, Thomas R.; Kaiser, William J.; Kenny, Thomas W.; Crisp, David

    1994-01-01

    Relatively inexpensive hygrometer that occupies volume less than 4 in.(3) measures dewpoints as much as 100 degrees C below ambient temperatures, with accuracy of 0.1 degrees C. Field tests indicate accuracy and repeatability identical to those of state-of-the-art larger dewpoint hygrometers. Operates up to 100 times as fast as older hygrometers, and offers simplicity and small size needed to meet cost and performance requirements of many applications.

  20. High performance Vernier racetrack resonators.

    PubMed

    Boeck, Robert; Flueckiger, Jonas; Yun, Han; Chrostowski, Lukas; Jaeger, Nicolas A F

    2012-12-15

    We demonstrate record performance of series-coupled silicon racetrack resonators exhibiting the Vernier effect. Our device has an interstitial peak suppression (IPS) of 25.5 dB, which is 14.5 dB larger than previously reported results. We also demonstrate the relationship between the inter-ring gap distance and the IPS as well as the 3 dB bandwidth (BW) both theoretically and experimentally. Namely, we show that as the inter-ring gap distance increases, the IPS increases and the 3 dB BW decreases.

  1. High-performance solar collector

    NASA Technical Reports Server (NTRS)

    Beekley, D. C.; Mather, G. R., Jr.

    1979-01-01

    Evacuated all-glass concentric tube collector using air or liquid transfer mediums is very efficient at high temperatures. Collector can directly drive existing heating systems that are presently driven by fossil fuel with relative ease of conversion and less expense than installation of complete solar heating systems.

  2. High-performance magnetic gears

    NASA Astrophysics Data System (ADS)

    Atallah, Kais; Calverley, Stuart D.; Howe, David

    2004-05-01

    Magnetic gearing may offer significant advantages such as reduced maintenance and improved reliability, inherent overload protection, and physical isolation between input and output shafts. Despite these advantages, it has received relatively little attention, to date, probably due to the poor torque transmission capability of proposed magnetic gears. The paper describes a magnetic gear topology, which combines a significantly higher torque transmission capability and a very high efficiency.

  3. High performance rotational vibration isolator

    NASA Astrophysics Data System (ADS)

    Sunderland, Andrew; Blair, David G.; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

    2013-10-01

    We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

  4. High performance rotational vibration isolator.

    PubMed

    Sunderland, Andrew; Blair, David G; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

    2013-10-01

    We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

  5. Molten Carbonate Fuel Cell performance analysis varying cathode operating conditions for carbon capture applications

    NASA Astrophysics Data System (ADS)

    Audasso, Emilio; Barelli, Linda; Bidini, Gianni; Bosio, Barbara; Discepoli, Gabriele

    2017-04-01

    The results of a systematic experimental campaign to verify the impact of real operating conditions on the performance of a complete Molten Carbonate Fuel Cell (MCFC) are presented. In particular, the effects of ageing and composition of water, oxygen and carbon dioxide in the cathodic feeding stream are studied through the analysis of current-voltage curves and Electrochemical Impedance Spectroscopy (EIS). Based on a proposed equivalent electrical circuit model and a fitting procedure, a correlation is found among specific operating parameters and single EIS coefficients. The obtained results suggest a new performance monitoring approach to be applied to MCFC for diagnostic purpose. Particular attention is devoted to operating conditions characteristic of MCFC application as CO2 concentrators, which, by feeding the cathode with exhaust gases, is a promising route for efficient and cheap carbon capture.

  6. High performance light emitting transistors

    NASA Astrophysics Data System (ADS)

    Namdas, Ebinazar B.; Ledochowitsch, Peter; Yuen, Jonathan D.; Moses, Daniel; Heeger, Alan J.

    2008-05-01

    Solution processed light emitting field-effect transistors (LEFETs) with peak brightness exceeding 2500cd/m2 and external quantum efficiency of 0.15% are demonstrated. The devices utilized a bilayer film comprising a hole transporting polymer, poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b] thiophene) and a light emitting polymer, Super Yellow, a polyphenylenevinylene derivative. The LEFETs were fabricated in the bottom gate architecture with top-contact Ca /Ag as source/drain electrodes. Light emission was controlled by the gate voltage which controls the hole current. These results indicate that high brightness LEFETs can be made by using the bilayer film (hole transporting layer and a light emitting polymer).

  7. Designing high-performance jobs.

    PubMed

    Simons, Robert

    2005-01-01

    Tales of great strategies derailed by poor execution are all too common. That's because some organizations are designed to fail. For a company to achieve its potential, each employee's supply of organizational resources should equal the demand, and the same balance must apply to every business unit and to the company as a whole. To carry out his or her job, each employee has to know the answers to four basic questions: What resources do I control to accomplish my tasks? What measures will be used to evaluate my performance? Who do I need to interact with and influence to achieve my goals? And how much support can I expect when I reach out to others for help? The questions correspond to what the author calls the four basic spans of a job-control, accountability, influence, and support. Each span can be adjusted so that it is narrow or wide or somewhere in between. If you get the settings right, you can design a job in which a talented individual can successfully execute on your company's strategy. If you get the settings wrong, it will be difficult for an employee to be effective. The first step is to set the span of control to reflect the resources allocated to each position and unit that plays an important role in delivering customer value. This setting, like the others, is determined by how the business creates value for customers and differentiates its products and services. Next, you can dial in different levels of entrepreneurial behavior and creative tension by widening or narrowing spans of accountability and influence. Finally, you must adjust the span of support to ensure that the job or unit will get the informal help it needs.

  8. HIGH-PERFORMANCE COATING MATERIALS

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    Corrosion, erosion, oxidation, and fouling by scale deposits impose critical issues in selecting the metal components used at geothermal power plants operating at brine temperatures up to 300 C. Replacing these components is very costly and time consuming. Currently, components made of titanium alloy and stainless steel commonly are employed for dealing with these problems. However, another major consideration in using these metals is not only that they are considerably more expensive than carbon steel, but also the susceptibility of corrosion-preventing passive oxide layers that develop on their outermost surface sites to reactions with brine-induced scales, such as silicate, silica, and calcite. Such reactions lead to the formation of strong interfacial bonds between the scales and oxide layers, causing the accumulation of multiple layers of scales, and the impairment of the plant component's function and efficacy; furthermore, a substantial amount of time is entailed in removing them. This cleaning operation essential for reusing the components is one of the factors causing the increase in the plant's maintenance costs. If inexpensive carbon steel components could be coated and lined with cost-effective high-hydrothermal temperature stable, anti-corrosion, -oxidation, and -fouling materials, this would improve the power plant's economic factors by engendering a considerable reduction in capital investment, and a decrease in the costs of operations and maintenance through optimized maintenance schedules.

  9. Statistical properties of high performance cesium standards

    NASA Technical Reports Server (NTRS)

    Percival, D. B.

    1973-01-01

    The intermediate term frequency stability of a group of new high-performance cesium beam tubes at the U.S. Naval Observatory were analyzed from two viewpoints: (1) by comparison of the high-performance standards to the MEAN(USNO) time scale and (2) by intercomparisons among the standards themselves. For sampling times up to 5 days, the frequency stability of the high-performance units shows significant improvement over older commercial cesium beam standards.

  10. Method of making a high performance ultracapacitor

    DOEpatents

    Farahmandi, C. Joseph; Dispennette, John M.

    2000-07-26

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

  11. High performance carbon nanocomposites for ultracapacitors

    DOEpatents

    Lu, Wen

    2012-10-02

    The present invention relates to composite electrodes for electrochemical devices, particularly to carbon nanotube composite electrodes for high performance electrochemical devices, such as ultracapacitors.

  12. Strategy Guideline: High Performance Residential Lighting

    SciTech Connect

    Holton, J.

    2012-02-01

    The Strategy Guideline: High Performance Residential Lighting has been developed to provide a tool for the understanding and application of high performance lighting in the home. The high performance lighting strategies featured in this guide are drawn from recent advances in commercial lighting for application to typical spaces found in residential buildings. This guide offers strategies to greatly reduce lighting energy use through the application of high quality fluorescent and light emitting diode (LED) technologies. It is important to note that these strategies not only save energy in the home but also serve to satisfy the homeowner's expectations for high quality lighting.

  13. Turning High-Poverty Schools into High-Performing Schools

    ERIC Educational Resources Information Center

    Parrett, William H.; Budge, Kathleen

    2012-01-01

    If some schools can overcome the powerful and pervasive effects of poverty to become high performing, shouldn't any school be able to do the same? Shouldn't we be compelled to learn from those schools? Although schools alone will never systemically eliminate poverty, high-poverty, high-performing (HP/HP) schools take control of what they can to…

  14. Common Factors of High Performance Teams

    ERIC Educational Resources Information Center

    Jackson, Bruce; Madsen, Susan R.

    2005-01-01

    Utilization of work teams is now wide spread in all types of organizations throughout the world. However, an understanding of the important factors common to high performance teams is rare. The purpose of this content analysis is to explore the literature and propose findings related to high performance teams. These include definition and types,…

  15. High performance computing at Sandia National Labs

    SciTech Connect

    Cahoon, R.M.; Noe, J.P.; Vandevender, W.H.

    1995-10-01

    Sandia`s High Performance Computing Environment requires a hierarchy of resources ranging from desktop, to department, to centralized, and finally to very high-end corporate resources capable of teraflop performance linked via high-capacity Asynchronous Transfer Mode (ATM) networks. The mission of the Scientific Computing Systems Department is to provide the support infrastructure for an integrated corporate scientific computing environment that will meet Sandia`s needs in high-performance and midrange computing, network storage, operational support tools, and systems management. This paper describes current efforts at SNL/NM to expand and modernize centralized computing resources in support of this mission.

  16. LANL High-Performance Data System (HPDS)

    NASA Technical Reports Server (NTRS)

    Collins, M. William; Cook, Danny; Jones, Lynn; Kluegel, Lynn; Ramsey, Cheryl

    1993-01-01

    The Los Alamos High-Performance Data System (HPDS) is being developed to meet the very large data storage and data handling requirements of a high-performance computing environment. The HPDS will consist of fast, large-capacity storage devices that are directly connected to a high-speed network and managed by software distributed in workstations. The HPDS model, the HPDS implementation approach, and experiences with a prototype disk array storage system are presented.

  17. Strategy Guideline. Partnering for High Performance Homes

    SciTech Connect

    Prahl, Duncan

    2013-01-01

    High performance houses require a high degree of coordination and have significant interdependencies between various systems in order to perform properly, meet customer expectations, and minimize risks for the builder. Responsibility for the key performance attributes is shared across the project team and can be well coordinated through advanced partnering strategies. For high performance homes, traditional partnerships need to be matured to the next level and be expanded to all members of the project team including trades, suppliers, manufacturers, HERS raters, designers, architects, and building officials as appropriate. This guide is intended for use by all parties associated in the design and construction of high performance homes. It serves as a starting point and features initial tools and resources for teams to collaborate to continually improve the energy efficiency and durability of new houses.

  18. ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS

    SciTech Connect

    WONG, CPC; MALANG, S; NISHIO, S; RAFFRAY, R; SAGARA, S

    2002-04-01

    OAK A271 ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS. First wall and blanket (FW/blanket) design is a crucial element in the performance and acceptance of a fusion power plant. High temperature structural and breeding materials are needed for high thermal performance. A suitable combination of structural design with the selected materials is necessary for D-T fuel sufficiency. Whenever possible, low afterheat, low chemical reactivity and low activation materials are desired to achieve passive safety and minimize the amount of high-level waste. Of course the selected fusion FW/blanket design will have to match the operational scenarios of high performance plasma. The key characteristics of eight advanced high performance FW/blanket concepts are presented in this paper. Design configurations, performance characteristics, unique advantages and issues are summarized. All reviewed designs can satisfy most of the necessary design goals. For further development, in concert with the advancement in plasma control and scrape off layer physics, additional emphasis will be needed in the areas of first wall coating material selection, design of plasma stabilization coils, consideration of reactor startup and transient events. To validate the projected performance of the advanced FW/blanket concepts the critical element is the need for 14 MeV neutron irradiation facilities for the generation of necessary engineering design data and the prediction of FW/blanket components lifetime and availability.

  19. Advanced high-performance computer system architectures

    NASA Astrophysics Data System (ADS)

    Vinogradov, V. I.

    2007-02-01

    Convergence of computer systems and communication technologies are moving to switched high-performance modular system architectures on the basis of high-speed switched interconnections. Multi-core processors become more perspective way to high-performance system, and traditional parallel bus system architectures (VME/VXI, cPCI/PXI) are moving to new higher speed serial switched interconnections. Fundamentals in system architecture development are compact modular component strategy, low-power processor, new serial high-speed interface chips on the board, and high-speed switched fabric for SAN architectures. Overview of advanced modular concepts and new international standards for development high-performance embedded and compact modular systems for real-time applications are described.

  20. Dinosaurs can fly -- High performance refining

    SciTech Connect

    Treat, J.E.

    1995-09-01

    High performance refining requires that one develop a winning strategy based on a clear understanding of one`s position in one`s company`s value chain; one`s competitive position in the products markets one serves; and the most likely drivers and direction of future market forces. The author discussed all three points, then described measuring performance of the company. To become a true high performance refiner often involves redesigning the organization as well as the business processes. The author discusses such redesigning. The paper summarizes ten rules to follow to achieve high performance: listen to the market; optimize; organize around asset or area teams; trust the operators; stay flexible; source strategically; all maintenance is not equal; energy is not free; build project discipline; and measure and reward performance. The paper then discusses the constraints to the implementation of change.

  1. Rapidly Reconfigurable High Performance Computing Cluster

    DTIC Science & Technology

    2005-07-01

    1 SECTION 2 BACKGROUN D AN D OBJECTIVES ......................................................................... 2 2.1 H...igh Perform ance Com puting Trends ................................................................................ 2 2.2 Georgia Tech Activity in H PEC

  2. High Performance Split-Stirling Cooler Program

    DTIC Science & Technology

    1982-09-01

    7 SPLIT- STIRLING CYCLE CRYOCOOLER . ...... . . . . . 13 8 TEMPERATURE-SHOCK COMPARISON PERFORMANCE DATA, S/N 002 . . 23 9 TEMPERATURE-SHOCK...PERFORMANCE SPLIT- STIRLING "COOLER PROGRAM FINAL TECHNICAL REPORT "September 1982 Prepared for NIGHT VISION AND ELECTRO-OPTICS LABORATORI ES "Contract DAAK70...REPORT & P.Vt2OO COVERED HIGH PERFORMANCE SPLIT- STIRLING COOLER PROGRAM Final Technical Sept. 1979. - Sept. 1982 S. PERPORMING ORO. REPORT KUMMER

  3. Architecture Analysis of High Performance Capacitors (POSTPRINT)

    DTIC Science & Technology

    2009-07-01

    includes the measurement of heat dissipated from a recently developed fluorenyl polyester (FPE) capacitor under an AC excitation. II. Capacitor ...AFRL-RZ-WP-TP-2010-2100 ARCHITECTURE ANALYSIS OF HIGH PERFORMANCE CAPACITORS (POSTPRINT) Hiroyuki Kosai and Tyler Bixel UES, Inc...2009 4. TITLE AND SUBTITLE ARCHITECTURE ANALYSIS OF HIGH PERFORMANCE CAPACITORS (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c

  4. Highlighting High Performance: Whitman Hanson Regional High School; Whitman, Massachusetts

    SciTech Connect

    Not Available

    2006-06-01

    This brochure describes the key high-performance building features of the Whitman-Hanson Regional High School. The brochure was paid for by the Massachusetts Technology Collaborative as part of their Green Schools Initiative. High-performance features described are daylighting and energy-efficient lighting, indoor air quality, solar and wind energy, building envelope, heating and cooling systems, water conservation, and acoustics. Energy cost savings are also discussed.

  5. High Performance Work Systems for Online Education

    ERIC Educational Resources Information Center

    Contacos-Sawyer, Jonna; Revels, Mark; Ciampa, Mark

    2010-01-01

    The purpose of this paper is to identify the key elements of a High Performance Work System (HPWS) and explore the possibility of implementation in an online institution of higher learning. With the projected rapid growth of the demand for online education and its importance in post-secondary education, providing high quality curriculum, excellent…

  6. Overview of high performance aircraft propulsion research

    NASA Technical Reports Server (NTRS)

    Biesiadny, Thomas J.

    1992-01-01

    The overall scope of the NASA Lewis High Performance Aircraft Propulsion Research Program is presented. High performance fighter aircraft of interest include supersonic flights with such capabilities as short take off and vertical landing (STOVL) and/or high maneuverability. The NASA Lewis effort involving STOVL propulsion systems is focused primarily on component-level experimental and analytical research. The high-maneuverability portion of this effort, called the High Alpha Technology Program (HATP), is part of a cooperative program among NASA's Lewis, Langley, Ames, and Dryden facilities. The overall objective of the NASA Inlet Experiments portion of the HATP, which NASA Lewis leads, is to develop and enhance inlet technology that will ensure high performance and stability of the propulsion system during aircraft maneuvers at high angles of attack. To accomplish this objective, both wind-tunnel and flight experiments are used to obtain steady-state and dynamic data, and computational fluid dynamics (CFD) codes are used for analyses. This overview of the High Performance Aircraft Propulsion Research Program includes a sampling of the results obtained thus far and plans for the future.

  7. Teacher Accountability at High Performing Charter Schools

    ERIC Educational Resources Information Center

    Aguirre, Moises G.

    2016-01-01

    This study will examine the teacher accountability and evaluation policies and practices at three high performing charter schools located in San Diego County, California. Charter schools are exempted from many laws, rules, and regulations that apply to traditional school systems. By examining the teacher accountability systems at high performing…

  8. Three Dimensional Forming Simulation of the Shielded Slot Plate for the MCFC Using a Ductile Fracture Criterion

    NASA Astrophysics Data System (ADS)

    Lee, C. H.; Yang, D. Y.; Lee, S. R.; Chang, I. G.; Lee, T. W.

    2011-08-01

    The shielded slot plate, which has a sheared corrugated trapezoidal pattern, is a component of the metallic bipolar plate for the molten carbonate fuel cell (MCFC). In order to increase the efficiency of the fuel cell, the unit cell of the shielded slot plate should have a relatively large upper area. Additionally, defects from the forming process should be minimized. In order to simulate the slitting process, whereby sheared corrugated patterns are formed, ductile fracture criteria based on the histories of stress and strain are employed. The user material subroutine VUMAT is employed for implementation of the material and ductile fracture criteria in the commercial FEM software ABAQUS. The variables of the ductile fracture criteria were determined by comparing the simulation results and the experimental results of the tension test and the shearing test. Parametric studies were conducted to determine the critical value of the ductile fracture criterion. Employing these ductile fracture criteria, the three dimensional forming process of the shielded slot plate was numerically simulated. The effects of the slitting process in the forming process of the shielded slot plate were analyzed through a FEM simulation and experimental studies. Finally, experiments involving microscopic and macroscopic observations were conducted to verify the numerical simulations of the 3-step forming process.

  9. High-performance computing and communications

    SciTech Connect

    Stevens, R.

    1993-11-01

    This presentation has two parts. The first part discusses the US High-Performance Computing and Communications program -- its goals, funding, process, revisions, and research in high-performance computing systems, advanced software technology, and basic research and human resources. The second part of the presentation covers specific work conducted under this program at Argonne National Laboratory. Argonne`s efforts focus on computational science research, software tool development, and evaluation of experimental computer architectures. In addition, the author describes collaborative activities at Argonne in high-performance computing, including an Argonne/IBM project to evaluate and test IBM`s newest parallel computers and the Scalable I/O Initiative being spearheaded by the Concurrent Supercomputing Consortium.

  10. Engineering high-performance vertical cavity lasers

    SciTech Connect

    Lear, K.L.; Hou, H.Q.; Hietala, V.M.; Choquette, K.D.; Schneider, R.P. Jr.

    1996-12-31

    The cw and high-speed performance of vertical cavity surface emitting laser diodes (VCSELs) are affected by both electrical and optical issues arising from the geometry and fabrication of these devices. Structures with low resistance semiconductor mirrors and Al-oxide confinement layers address these issues and have produced record performance including 50% power conversion efficiency and modulation bandwidths up to 20 GHz at small bias currents.

  11. Massive Contingency Analysis with High Performance Computing

    SciTech Connect

    Huang, Zhenyu; Chen, Yousu; Nieplocha, Jaroslaw

    2009-07-26

    Contingency analysis is a key function in the Energy Management System (EMS) to assess the impact of various combinations of power system component failures based on state estimates. Contingency analysis is also extensively used in power market operation for feasibility test of market solutions. Faster analysis of more cases is required to safely and reliably operate today’s power grids with less marginal and more intermittent renewable energy sources. Enabled by the latest development in the computer industry, high performance computing holds the promise of meet the need in the power industry. This paper investigates the potential of high performance computing for massive contingency analysis. The framework of "N-x" contingency analysis is established and computational load balancing schemes are studied and implemented with high performance computers. Case studies of massive 300,000-contingency-case analysis using the Western Electricity Coordinating Council power grid model are presented to illustrate the application of high performance computing and demonstrate the performance of the framework and computational load balancing schemes.

  12. Performance variability of highly parallel architectures

    SciTech Connect

    Kramer, William T.C.; Ryan, Clint

    2003-05-01

    The design and evaluation of high performance computers has concentrated on increasing computational speed for applications. This performance is often measured on a well configured dedicated system to show the best case. In the real environment, resources are not always dedicated to a single task, and systems run tasks that may influence each other, so run times vary, sometimes to an unreasonably large extent. This paper explores the amount of variation seen across four large distributed memory systems in a systematic manner. It then analyzes the causes for the variations seen and discusses what can be done to decrease the variation without impacting performance.

  13. Achieving High Performance Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  14. Properties of LiCoO{sub 2}-coated NiO MCFC cathode

    SciTech Connect

    Kuk, S.T.; Kim, C.K.; Chun, H.S.; Kwon, H.J.

    1996-12-31

    PVA-assisted sol-gel method is useful in producing metal oxides with large surface area at low temperature. We fabricated LiCoO{sub 2}-coated NiO(LC-NiO) cathode by PVA-assisted sol-gel method and measured its properties, The electrical conductivity of LC-NiO cathode was measured to be more than 5 times as high as that of NiO and unit cell test showed improved performance. From the SEM images and Raman spectra. we confirmed that the structure of LC-NiO was different from that of NiO. For 250 hours of steady operation of unit cells. the mean voltage of the cells were 0.78V for NiO and 0.85V for LiCoO{sub 2}-Coated NiO at a current density of l50mA/cm{sup 2}.

  15. High Performance Multiwall Carbon Nanotube Bolometers

    DTIC Science & Technology

    2010-10-21

    REPORT High performance multiwall carbon nanotube bolometers 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: High infrared bolometric photoresponse has...been observed in multiwall carbon nanotube MWCNT films at room temperature. The observed detectivity D in exceeding 3.3 106 cm Hz1/2 /W on MWCNT film...U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS carbon nanotube, infrared detector, bolometer

  16. Strategy Guideline: Partnering for High Performance Homes

    SciTech Connect

    Prahl, D.

    2013-01-01

    High performance houses require a high degree of coordination and have significant interdependencies between various systems in order to perform properly, meet customer expectations, and minimize risks for the builder. Responsibility for the key performance attributes is shared across the project team and can be well coordinated through advanced partnering strategies. For high performance homes, traditional partnerships need to be matured to the next level and be expanded to all members of the project team including trades, suppliers, manufacturers, HERS raters, designers, architects, and building officials as appropriate. In an environment where the builder is the only source of communication between trades and consultants and where relationships are, in general, adversarial as opposed to cooperative, the chances of any one building system to fail are greater. Furthermore, it is much harder for the builder to identify and capitalize on synergistic opportunities. Partnering can help bridge the cross-functional aspects of the systems approach and achieve performance-based criteria. Critical success factors for partnering include support from top management, mutual trust, effective and open communication, effective coordination around common goals, team building, appropriate use of an outside facilitator, a partnering charter progress toward common goals, an effective problem-solving process, long-term commitment, continuous improvement, and a positive experience for all involved.

  17. Task parallelism and high-performance languages

    SciTech Connect

    Foster, I.

    1996-03-01

    The definition of High Performance Fortran (HPF) is a significant event in the maturation of parallel computing: it represents the first parallel language that has gained widespread support from vendors and users. The subject of this paper is to incorporate support for task parallelism. The term task parallelism refers to the explicit creation of multiple threads of control, or tasks, which synchronize and communicate under programmer control. Task and data parallelism are complementary rather than competing programming models. While task parallelism is more general and can be used to implement algorithms that are not amenable to data-parallel solutions, many problems can benefit from a mixed approach, with for example a task-parallel coordination layer integrating multiple data-parallel computations. Other problems admit to both data- and task-parallel solutions, with the better solution depending on machine characteristics, compiler performance, or personal taste. For these reasons, we believe that a general-purpose high-performance language should integrate both task- and data-parallel constructs. The challenge is to do so in a way that provides the expressivity needed for applications, while preserving the flexibility and portability of a high-level language. In this paper, we examine and illustrate the considerations that motivate the use of task parallelism. We also describe one particular approach to task parallelism in Fortran, namely the Fortran M extensions. Finally, we contrast Fortran M with other proposed approaches and discuss the implications of this work for task parallelism and high-performance languages.

  18. Commercial Buildings High Performance Rooftop Unit Challenge

    SciTech Connect

    2011-12-16

    The U.S. Department of Energy (DOE) and the Commercial Building Energy Alliances (CBEAs) are releasing a new design specification for high performance rooftop air conditioning units (RTUs). Manufacturers who develop RTUs based on this new specification will find strong interest from the commercial sector due to the energy and financial savings.

  19. Project materials [Commercial High Performance Buildings Project

    SciTech Connect

    2001-01-01

    The Consortium for High Performance Buildings (ChiPB) is an outgrowth of DOE'S Commercial Whole Buildings Roadmapping initiatives. It is a team-driven public/private partnership that seeks to enable and demonstrate the benefit of buildings that are designed, built and operated to be energy efficient, environmentally sustainable, superior quality, and cost effective.

  20. High Performance Computing and Communications Panel Report.

    ERIC Educational Resources Information Center

    President's Council of Advisors on Science and Technology, Washington, DC.

    This report offers advice on the strengths and weaknesses of the High Performance Computing and Communications (HPCC) initiative, one of five presidential initiatives launched in 1992 and coordinated by the Federal Coordinating Council for Science, Engineering, and Technology. The HPCC program has the following objectives: (1) to extend U.S.…

  1. Debugging a high performance computing program

    DOEpatents

    Gooding, Thomas M.

    2013-08-20

    Methods, apparatus, and computer program products are disclosed for debugging a high performance computing program by gathering lists of addresses of calling instructions for a plurality of threads of execution of the program, assigning the threads to groups in dependence upon the addresses, and displaying the groups to identify defective threads.

  2. Debugging a high performance computing program

    DOEpatents

    Gooding, Thomas M.

    2014-08-19

    Methods, apparatus, and computer program products are disclosed for debugging a high performance computing program by gathering lists of addresses of calling instructions for a plurality of threads of execution of the program, assigning the threads to groups in dependence upon the addresses, and displaying the groups to identify defective threads.

  3. High-Performance, Low Environmental Impact Refrigerants

    NASA Technical Reports Server (NTRS)

    McCullough, E. T.; Dhooge, P. M.; Glass, S. M.; Nimitz, J. S.

    2001-01-01

    Refrigerants used in process and facilities systems in the US include R-12, R-22, R-123, R-134a, R-404A, R-410A, R-500, and R-502. All but R-134a, R-404A, and R-410A contain ozone-depleting substances that will be phased out under the Montreal Protocol. Some of the substitutes do not perform as well as the refrigerants they are replacing, require new equipment, and have relatively high global warming potentials (GWPs). New refrigerants are needed that addresses environmental, safety, and performance issues simultaneously. In efforts sponsored by Ikon Corporation, NASA Kennedy Space Center (KSC), and the US Environmental Protection Agency (EPA), ETEC has developed and tested a new class of refrigerants, the Ikon (registered) refrigerants, based on iodofluorocarbons (IFCs). These refrigerants are nonflammable, have essentially zero ozone-depletion potential (ODP), low GWP, high performance (energy efficiency and capacity), and can be dropped into much existing equipment.

  4. High performance flight simulation at NASA Langley

    NASA Technical Reports Server (NTRS)

    Cleveland, Jeff I., II; Sudik, Steven J.; Grove, Randall D.

    1992-01-01

    The use of real-time simulation at the NASA facility is reviewed specifically with regard to hardware, software, and the use of a fiberoptic-based digital simulation network. The network hardware includes supercomputers that support 32- and 64-bit scalar, vector, and parallel processing technologies. The software include drivers, real-time supervisors, and routines for site-configuration management and scheduling. Performance specifications include: (1) benchmark solution at 165 sec for a single CPU; (2) a transfer rate of 24 million bits/s; and (3) time-critical system responsiveness of less than 35 msec. Simulation applications include the Differential Maneuvering Simulator, Transport Systems Research Vehicle simulations, and the Visual Motion Simulator. NASA is shown to be in the final stages of developing a high-performance computing system for the real-time simulation of complex high-performance aircraft.

  5. Strategy Guideline. High Performance Residential Lighting

    SciTech Connect

    Holton, J.

    2012-02-01

    This report has been developed to provide a tool for the understanding and application of high performance lighting in the home. The strategies featured in this guide are drawn from recent advances in commercial lighting for application to typical spaces found in residential buildings. This guide offers strategies to greatly reduce lighting energy use through the application of high quality fluorescent and light emitting diode (LED) technologies. It is important to note that these strategies not only save energy in the home but also serve to satisfy the homeowner’s expectations for high quality lighting.

  6. High voltage electric substation performance in earthquakes

    SciTech Connect

    Eidinger, J.; Ostrom, D.; Matsuda, E.

    1995-12-31

    This paper examines the performance of several types of high voltage substation equipment in past earthquakes. Damage data is provided in chart form. This data is then developed into a tool for estimating the performance of a substation subjected to an earthquake. First, suggests are made about the development of equipment class fragility curves that represent the expected earthquake performance of different voltages and types of equipment. Second, suggestions are made about how damage to individual pieces of equipment at a substation likely affects the post-earthquake performance of the substation as a whole. Finally, estimates are provided as to how quickly a substation, at various levels of damage, can be restored to operational service after the earthquake.

  7. High Performance Woven Mesh Heat Exchangers

    NASA Astrophysics Data System (ADS)

    Wirtz, Richard A.; Li, Chen; Park, Ji-Wook; Xu, Jun

    2002-07-01

    Simple-to-fabricate woven mesh structures, consisting of bonded laminates of two-dimensional plain-weave conductive screens, or three-dimensional orthogonal weaves are described. Geometric equations show that these porous matrices can be fabricated to have a wide range of porosity and a highly anisotropic thermal conductivity vector. A mathematical model of the thermal performance of such a mesh, deployed as a heat exchange surface, is developed. Measurements of pressure drop and overall heat transfer rate are reported and used with the performance model to develop correlation equations of mesh friction factor and Colburn j-factor as a function of coolant properties, mesh characteristics and flow rate through the mesh. A heat exchanger performance analysis delineates conditions where the two mesh technologies offer superior performance.

  8. Failure analysis of high performance ballistic fibers

    NASA Astrophysics Data System (ADS)

    Spatola, Jennifer S.

    High performance fibers have a high tensile strength and modulus, good wear resistance, and a low density, making them ideal for applications in ballistic impact resistance, such as body armor. However, the observed ballistic performance of these fibers is much lower than the predicted values. Since the predictions assume only tensile stress failure, it is safe to assume that the stress state is affecting fiber performance. The purpose of this research was to determine if there are failure mode changes in the fiber fracture when transversely loaded by indenters of different shapes. An experimental design mimicking transverse impact was used to determine any such effects. Three different indenters were used: round, FSP, and razor blade. The indenter height was changed to change the angle of failure tested. Five high performance fibers were examined: KevlarRTM KM2, SpectraRTM 130d, DyneemaRTM SK-62 and SK-76, and ZylonRTM 555. Failed fibers were analyzed using an SEM to determine failure mechanisms. The results show that the round and razor blade indenters produced a constant failure strain, as well as failure mechanisms independent of testing angle. The FSP indenter produced a decrease in failure strain as the angle increased. Fibrillation was the dominant failure mechanism at all angles for the round indenter, while through thickness shearing was the failure mechanism for the razor blade. The FSP indenter showed a transition from fibrillation at low angles to through thickness shearing at high angles, indicating that the round and razor blade indenters are extreme cases of the FSP indenter. The failure mechanisms observed with the FSP indenter at various angles correlated with the experimental strain data obtained during fiber testing. This indicates that geometry of the indenter tip in compression is a contributing factor in lowering the failure strain of the high performance fibers. TEM analysis of the fiber failure mechanisms was also attempted, though without

  9. High performance anode for advanced Li batteries

    SciTech Connect

    Lake, Carla

    2015-11-02

    The overall objective of this Phase I SBIR effort was to advance the manufacturing technology for ASI’s Si-CNF high-performance anode by creating a framework for large volume production and utilization of low-cost Si-coated carbon nanofibers (Si-CNF) for the battery industry. This project explores the use of nano-structured silicon which is deposited on a nano-scale carbon filament to achieve the benefits of high cycle life and high charge capacity without the consequent fading of, or failure in the capacity resulting from stress-induced fracturing of the Si particles and de-coupling from the electrode. ASI’s patented coating process distinguishes itself from others, in that it is highly reproducible, readily scalable and results in a Si-CNF composite structure containing 25-30% silicon, with a compositionally graded interface at the Si-CNF interface that significantly improve cycling stability and enhances adhesion of silicon to the carbon fiber support. In Phase I, the team demonstrated the production of the Si-CNF anode material can successfully be transitioned from a static bench-scale reactor into a fluidized bed reactor. In addition, ASI made significant progress in the development of low cost, quick testing methods which can be performed on silicon coated CNFs as a means of quality control. To date, weight change, density, and cycling performance were the key metrics used to validate the high performance anode material. Under this effort, ASI made strides to establish a quality control protocol for the large volume production of Si-CNFs and has identified several key technical thrusts for future work. Using the results of this Phase I effort as a foundation, ASI has defined a path forward to commercialize and deliver high volume and low-cost production of SI-CNF material for anodes in Li-ion batteries.

  10. A Linux Workstation for High Performance Graphics

    NASA Technical Reports Server (NTRS)

    Geist, Robert; Westall, James

    2000-01-01

    The primary goal of this effort was to provide a low-cost method of obtaining high-performance 3-D graphics using an industry standard library (OpenGL) on PC class computers. Previously, users interested in doing substantial visualization or graphical manipulation were constrained to using specialized, custom hardware most often found in computers from Silicon Graphics (SGI). We provided an alternative to expensive SGI hardware by taking advantage of third-party, 3-D graphics accelerators that have now become available at very affordable prices. To make use of this hardware our goal was to provide a free, redistributable, and fully-compatible OpenGL work-alike library so that existing bodies of code could simply be recompiled. for PC class machines running a free version of Unix. This should allow substantial cost savings while greatly expanding the population of people with access to a serious graphics development and viewing environment. This should offer a means for NASA to provide a spectrum of graphics performance to its scientists, supplying high-end specialized SGI hardware for high-performance visualization while fulfilling the requirements of medium and lower performance applications with generic, off-the-shelf components and still maintaining compatibility between the two.

  11. High Performance Commercial Fenestration Framing Systems

    SciTech Connect

    Mike Manteghi; Sneh Kumar; Joshua Early; Bhaskar Adusumalli

    2010-01-31

    A major objective of the U.S. Department of Energy is to have a zero energy commercial building by the year 2025. Windows have a major influence on the energy performance of the building envelope as they control over 55% of building energy load, and represent one important area where technologies can be developed to save energy. Aluminum framing systems are used in over 80% of commercial fenestration products (i.e. windows, curtain walls, store fronts, etc.). Aluminum framing systems are often required in commercial buildings because of their inherent good structural properties and long service life, which is required from commercial and architectural frames. At the same time, they are lightweight and durable, requiring very little maintenance, and offer design flexibility. An additional benefit of aluminum framing systems is their relatively low cost and easy manufacturability. Aluminum, being an easily recyclable material, also offers sustainable features. However, from energy efficiency point of view, aluminum frames have lower thermal performance due to the very high thermal conductivity of aluminum. Fenestration systems constructed of aluminum alloys therefore have lower performance in terms of being effective barrier to energy transfer (heat loss or gain). Despite the lower energy performance, aluminum is the choice material for commercial framing systems and dominates the commercial/architectural fenestration market because of the reasons mentioned above. In addition, there is no other cost effective and energy efficient replacement material available to take place of aluminum in the commercial/architectural market. Hence it is imperative to improve the performance of aluminum framing system to improve the energy performance of commercial fenestration system and in turn reduce the energy consumption of commercial building and achieve zero energy building by 2025. The objective of this project was to develop high performance, energy efficient commercial

  12. An Introduction to High Performance Computing

    NASA Astrophysics Data System (ADS)

    Almeida, Sérgio

    2013-09-01

    High Performance Computing (HPC) has become an essential tool in every researcher's arsenal. Most research problems nowadays can be simulated, clarified or experimentally tested by using computational simulations. Researchers struggle with computational problems when they should be focusing on their research problems. Since most researchers have little-to-no knowledge in low-level computer science, they tend to look at computer programs as extensions of their minds and bodies instead of completely autonomous systems. Since computers do not work the same way as humans, the result is usually Low Performance Computing where HPC would be expected.

  13. High performance FDTD algorithm for GPGPU supercomputers

    NASA Astrophysics Data System (ADS)

    Zakirov, Andrey; Levchenko, Vadim; Perepelkina, Anastasia; Zempo, Yasunari

    2016-10-01

    An implementation of FDTD method for solution of optical and other electrodynamic problems of high computational cost is described. The implementation is based on the LRnLA algorithm DiamondTorre, which is developed specifically for GPGPU hardware. The specifics of the DiamondTorre algorithms for staggered grid (Yee cell) and many-GPU devices are shown. The algorithm is implemented in the software for real physics calculation. The software performance is estimated through algorithms parameters and computer model. The real performance is tested on one GPU device, as well as on the many-GPU cluster. The performance of up to 0.65 • 1012 cell updates per second for 3D domain with 0.3 • 1012 Yee cells total is achieved.

  14. Evaluation of high-performance computing software

    SciTech Connect

    Browne, S.; Dongarra, J.; Rowan, T.

    1996-12-31

    The absence of unbiased and up to date comparative evaluations of high-performance computing software complicates a user`s search for the appropriate software package. The National HPCC Software Exchange (NHSE) is attacking this problem using an approach that includes independent evaluations of software, incorporation of author and user feedback into the evaluations, and Web access to the evaluations. We are applying this approach to the Parallel Tools Library (PTLIB), a new software repository for parallel systems software and tools, and HPC-Netlib, a high performance branch of the Netlib mathematical software repository. Updating the evaluations with feed-back and making it available via the Web helps ensure accuracy and timeliness, and using independent reviewers produces unbiased comparative evaluations difficult to find elsewhere.

  15. Monitoring SLAC High Performance UNIX Computing Systems

    SciTech Connect

    Lettsome, Annette K.; /Bethune-Cookman Coll. /SLAC

    2005-12-15

    Knowledge of the effectiveness and efficiency of computers is important when working with high performance systems. The monitoring of such systems is advantageous in order to foresee possible misfortunes or system failures. Ganglia is a software system designed for high performance computing systems to retrieve specific monitoring information. An alternative storage facility for Ganglia's collected data is needed since its default storage system, the round-robin database (RRD), struggles with data integrity. The creation of a script-driven MySQL database solves this dilemma. This paper describes the process took in the creation and implementation of the MySQL database for use by Ganglia. Comparisons between data storage by both databases are made using gnuplot and Ganglia's real-time graphical user interface.

  16. Toward a theory of high performance.

    PubMed

    Kirby, Julia

    2005-01-01

    What does it mean to be a high-performance company? The process of measuring relative performance across industries and eras, declaring top performers, and finding the common drivers of their success is such a difficult one that it might seem a fool's errand to attempt. In fact, no one did for the first thousand or so years of business history. The question didn't even occur to many scholars until Tom Peters and Bob Waterman released In Search of Excellence in 1982. Twenty-three years later, we've witnessed several more attempts--and, just maybe, we're getting closer to answers. In this reported piece, HBR senior editor Julia Kirby explores why it's so difficult to study high performance and how various research efforts--including those from John Kotter and Jim Heskett; Jim Collins and Jerry Porras; Bill Joyce, Nitin Nohria, and Bruce Roberson; and several others outlined in a summary chart-have attacked the problem. The challenge starts with deciding which companies to study closely. Are the stars the ones with the highest market caps, the ones with the greatest sales growth, or simply the ones that remain standing at the end of the game? (And when's the end of the game?) Each major study differs in how it defines success, which companies it therefore declares to be worthy of emulation, and the patterns of activity and attitude it finds in common among them. Yet, Kirby concludes, as each study's method incrementally solves problems others have faced, we are progressing toward a consensus theory of high performance.

  17. High performance forward swept wing aircraft

    NASA Technical Reports Server (NTRS)

    Koenig, David G. (Inventor); Aoyagi, Kiyoshi (Inventor); Dudley, Michael R. (Inventor); Schmidt, Susan B. (Inventor)

    1988-01-01

    A high performance aircraft capable of subsonic, transonic and supersonic speeds employs a forward swept wing planform and at least one first and second solution ejector located on the inboard section of the wing. A high degree of flow control on the inboard sections of the wing is achieved along with improved maneuverability and control of pitch, roll and yaw. Lift loss is delayed to higher angles of attack than in conventional aircraft. In one embodiment the ejectors may be advantageously positioned spanwise on the wing while the ductwork is kept to a minimum.

  18. High Performance Databases For Scientific Applications

    NASA Technical Reports Server (NTRS)

    French, James C.; Grimshaw, Andrew S.

    1997-01-01

    The goal for this task is to develop an Extensible File System (ELFS). ELFS attacks the problem of the following: 1. Providing high bandwidth performance architectures; 2. Reducing the cognitive burden faced by applications programmers when they attempt to optimize; and 3. Seamlessly managing the proliferation of data formats and architectural differences. The approach for ELFS solution consists of language and run-time system support that permits the specification on a hierarchy of file classes.

  19. Tough, High-Performance, Thermoplastic Addition Polymers

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H.; Proctor, K. Mason; Gleason, John; Morgan, Cassandra; Partos, Richard

    1991-01-01

    Series of addition-type thermoplastics (ATT's) exhibit useful properties. Because of their addition curing and linear structure, ATT polymers have toughness, like thermoplastics, and easily processed, like thermosets. Work undertaken to develop chemical reaction forming stable aromatic rings in backbone of ATT polymer, combining high-temperature performance and thermo-oxidative stability with toughness and easy processibility, and minimizing or eliminating necessity for tradeoffs among properties often observed in conventional polymer syntheses.

  20. AHPCRC - Army High Performance Computing Research Center

    DTIC Science & Technology

    2010-01-01

    treatments and reconstructive surgeries . High performance computer simu- lation allows designers to try out numerous mechanical and material...investigating the effect of techniques for simplifying the calculations (sending the projectile through a pre-existing hole, for example) on the accuracy of...semiconductor particles are size-dependent. These properties, including yield strength and resistance to fatigue, are not well predicted by macroscopic

  1. AHPCRC - Army High Performance Computing Research Center

    DTIC Science & Technology

    2008-01-01

    materials “from the atoms up” or to model biological systems at the molecular level. The speed and capacity of massively parallel computers are key...Streamlined, massively parallel high performance computing structural codes allow researchers to examine many relevant physical factors simultaneously...expenditure of energy, so that the drones can carry their load of sensors, communications devices, and fuel. AHPCRC researchers are using massively

  2. High-performance reactionless scan mechanism

    NASA Technical Reports Server (NTRS)

    Williams, Ellen I.; Summers, Richard T.; Ostaszewski, Miroslaw A.

    1995-01-01

    A high-performance reactionless scan mirror mechanism was developed for space applications to provide thermal images of the Earth. The design incorporates a unique mechanical means of providing reactionless operation that also minimizes weight, mechanical resonance operation to minimize power, combined use of a single optical encoder to sense coarse and fine angular position, and a new kinematic mount of the mirror. A flex pivot hardware failure and current project status are discussed.

  3. Development of high performance BWR spacer

    SciTech Connect

    Morooka, Shinichi; Shirakawa, Kenetu; Mitutake, Tohru; Yamamoto, Yasushi; Yano, Takashi; Kimura, Jiro

    1996-07-01

    The spacer has a significant effect on thermal hydraulic performance of BWR fuel assembly. The purpose of this study is to develop a new BWR spacer with high critical power and low pressure drop performance. The developed high performance spacer is a ferrule type spacer with twisted tape and improved flow tab. This spacer is called CYCLONE spacer. Critical power and pressure drop have been measured at BEST (BWR Experimental Loop for Stability and Transient test) of Toshiba Corporation. The test bundle consists of electrically heated rods in a 4x4 array configuration. These heater rods are indirectly heated. The heated length and outer diameter of the heater rod, as well as the number and the axial locations of the spacers, are the same as for those for a BWR fuel assembly. The axial power shape is stepped cosine (1.4 of the maximum peaking factor). Two test assemblies with different radial power distribution have been used. One test assembly has the maximum power rods at the center of the test assembly and the other has the maximum power rods near the channel wall. The results show that the critical power performance of CYCLONE spacer is 10 to 25 % higher than that of the ferrule spacers, while the pressure drop for CYCLONE spacer is nearly equal to that of the ferrule spacer.

  4. High temperature furnace modeling and performance verifications

    NASA Technical Reports Server (NTRS)

    Smith, James E., Jr.

    1992-01-01

    Analytical, numerical, and experimental studies were performed on two classes of high temperature materials processing sources for their potential use as directional solidification furnaces. The research concentrated on a commercially available high temperature furnace using a zirconia ceramic tube as the heating element and an Arc Furnace based on a tube welder. The first objective was to assemble the zirconia furnace and construct parts needed to successfully perform experiments. The 2nd objective was to evaluate the zirconia furnace performance as a directional solidification furnace element. The 3rd objective was to establish a data base on materials used in the furnace construction, with particular emphasis on emissivities, transmissivities, and absorptivities as functions of wavelength and temperature. A 1-D and 2-D spectral radiation heat transfer model was developed for comparison with standard modeling techniques, and were used to predict wall and crucible temperatures. The 4th objective addressed the development of a SINDA model for the Arc Furnace and was used to design sample holders and to estimate cooling media temperatures for the steady state operation of the furnace. And, the 5th objective addressed the initial performance evaluation of the Arc Furnace and associated equipment for directional solidification. Results of these objectives are presented.

  5. Towards High-Assurance High-Performance Program Synthesis

    NASA Technical Reports Server (NTRS)

    Lowry, Michael; Roach, Steven; vanBaalen, Jeffrey

    1997-01-01

    Domain-specific automatic program synthesis tools, also called application generators, are playing an ever-increasing role in software development. However, high-performance application generators require difficult manual construction, and are very difficult to verify correct. This paper describes research and an implemented system that transforms program synthesis tools based on deductive synthesis into high-performance application generators. Deductive synthesis uses theorem-proving to construct solutions when given problem specifications. The verification condition for a deductive synthesis tool is essentially the soundness of the implemented inference rules. Theory Operationalization for Program Synthesis (TOPS) synergistically combines reformulation, automated mathematical classification, and compilation through partial deduction to decision procedures. It transforms general-purpose deductive synthesis, with exponential performance, into efficient special-purpose deductive synthesis, with near-linear performance. This paper describes our experience with and empirical results of PD(TH) theory-based partial deduction - in which partial deduction of a set of first-order formulae is performed within the context of a background theory. The implemented TOPS system currently performs a special variant of PD(TH) in which the compilation process results in the transformation of a set of first order formulae into the theory of an instantiated library decision procedure augmented by a compiled unit theory.

  6. Computational Biology and High Performance Computing 2000

    SciTech Connect

    Simon, Horst D.; Zorn, Manfred D.; Spengler, Sylvia J.; Shoichet, Brian K.; Stewart, Craig; Dubchak, Inna L.; Arkin, Adam P.

    2000-10-19

    The pace of extraordinary advances in molecular biology has accelerated in the past decade due in large part to discoveries coming from genome projects on human and model organisms. The advances in the genome project so far, happening well ahead of schedule and under budget, have exceeded any dreams by its protagonists, let alone formal expectations. Biologists expect the next phase of the genome project to be even more startling in terms of dramatic breakthroughs in our understanding of human biology, the biology of health and of disease. Only today can biologists begin to envision the necessary experimental, computational and theoretical steps necessary to exploit genome sequence information for its medical impact, its contribution to biotechnology and economic competitiveness, and its ultimate contribution to environmental quality. High performance computing has become one of the critical enabling technologies, which will help to translate this vision of future advances in biology into reality. Biologists are increasingly becoming aware of the potential of high performance computing. The goal of this tutorial is to introduce the exciting new developments in computational biology and genomics to the high performance computing community.

  7. Heavily Doped PBSE with High Thermoelectric Performance

    NASA Technical Reports Server (NTRS)

    Snyder, G. Jeffrey (Inventor); Wang, Heng (Inventor); Pei, Yanzhong (Inventor)

    2015-01-01

    The present invention discloses heavily doped PbSe with high thermoelectric performance. Thermoelectric property measurements disclosed herein indicated that PbSe is high zT material for mid-to-high temperature thermoelectric applications. At 850 K a peak zT (is) greater than 1.3 was observed when n(sub H) approximately 1.0 X 10(exp 20) cm(exp -3). The present invention also discloses that a number of strategies used to improve zT of PbTe, such as alloying with other elements, nanostructuring and band modification may also be used to further improve zT in PbSe.

  8. High Performance Fortran for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Mehrotra, Piyush; Zima, Hans; Bushnell, Dennis M. (Technical Monitor)

    2000-01-01

    This paper focuses on the use of High Performance Fortran (HPF) for important classes of algorithms employed in aerospace applications. HPF is a set of Fortran extensions designed to provide users with a high-level interface for programming data parallel scientific applications, while delegating to the compiler/runtime system the task of generating explicitly parallel message-passing programs. We begin by providing a short overview of the HPF language. This is followed by a detailed discussion of the efficient use of HPF for applications involving multiple structured grids such as multiblock and adaptive mesh refinement (AMR) codes as well as unstructured grid codes. We focus on the data structures and computational structures used in these codes and on the high-level strategies that can be expressed in HPF to optimally exploit the parallelism in these algorithms.

  9. A High Performance COTS Based Computer Architecture

    NASA Astrophysics Data System (ADS)

    Patte, Mathieu; Grimoldi, Raoul; Trautner, Roland

    2014-08-01

    Using Commercial Off The Shelf (COTS) electronic components for space applications is a long standing idea. Indeed the difference in processing performance and energy efficiency between radiation hardened components and COTS components is so important that COTS components are very attractive for use in mass and power constrained systems. However using COTS components in space is not straightforward as one must account with the effects of the space environment on the COTS components behavior. In the frame of the ESA funded activity called High Performance COTS Based Computer, Airbus Defense and Space and its subcontractor OHB CGS have developed and prototyped a versatile COTS based architecture for high performance processing. The rest of the paper is organized as follows: in a first section we will start by recapitulating the interests and constraints of using COTS components for space applications; then we will briefly describe existing fault mitigation architectures and present our solution for fault mitigation based on a component called the SmartIO; in the last part of the paper we will describe the prototyping activities executed during the HiP CBC project.

  10. High capacity heat pipe performance demonstration

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A high capacity heat pipe which will operate in one-g and in zero-g is investigated. An artery configuration which is self-priming in one-g was emphasized. Two artery modifications were evolved as candidates to achieve one-g priming and will provide the very high performance: the four artery and the eight artery configurations. These were each evaluated analytically for performance and priming capability. The eight artery configuration was found to be inadequate from a performance standpoint. The four artery showed promise of working. A five-inch long priming element test article was fabricated using the four artery design. Plexiglas viewing windows were made on each end of the heat pipe to permit viewing of the priming activity. The five-inch primary element would not successfully prime in one-g. Difficulties on priming in one-g raised questions about zero-g priming. Therefore a small test element heat pipe for verifying that the proposed configuration will self-prime in zero-g was fabricated and delivered.

  11. Towards high performance inverted polymer solar cells

    NASA Astrophysics Data System (ADS)

    Gong, Xiong

    2013-03-01

    Bulk heterojunction polymer solar cells that can be fabricated by solution processing techniques are under intense investigation in both academic institutions and industrial companies because of their potential to enable mass production of flexible and cost-effective alternative to silicon-based electronics. Despite the envisioned advantages and recent technology advances, so far the performance of polymer solar cells is still inferior to inorganic counterparts in terms of the efficiency and stability. There are many factors limiting the performance of polymer solar cells. Among them, the optical and electronic properties of materials in the active layer, device architecture and elimination of PEDOT:PSS are the most determining factors in the overall performance of polymer solar cells. In this presentation, I will present how we approach high performance of polymer solar cells. For example, by developing novel materials, fabrication polymer photovoltaic cells with an inverted device structure and elimination of PEDOT:PSS, we were able to observe over 8.4% power conversion efficiency from inverted polymer solar cells.

  12. RISC Processors and High Performance Computing

    NASA Technical Reports Server (NTRS)

    Saini, Subhash; Bailey, David H.; Lasinski, T. A. (Technical Monitor)

    1995-01-01

    In this tutorial, we will discuss top five current RISC microprocessors: The IBM Power2, which is used in the IBM RS6000/590 workstation and in the IBM SP2 parallel supercomputer, the DEC Alpha, which is in the DEC Alpha workstation and in the Cray T3D; the MIPS R8000, which is used in the SGI Power Challenge; the HP PA-RISC 7100, which is used in the HP 700 series workstations and in the Convex Exemplar; and the Cray proprietary processor, which is used in the new Cray J916. The architecture of these microprocessors will first be presented. The effective performance of these processors will then be compared, both by citing standard benchmarks and also in the context of implementing a real applications. In the process, different programming models such as data parallel (CM Fortran and HPF) and message passing (PVM and MPI) will be introduced and compared. The latest NAS Parallel Benchmark (NPB) absolute performance and performance per dollar figures will be presented. The next generation of the NP13 will also be described. The tutorial will conclude with a discussion of general trends in the field of high performance computing, including likely future developments in hardware and software technology, and the relative roles of vector supercomputers tightly coupled parallel computers, and clusters of workstations. This tutorial will provide a unique cross-machine comparison not available elsewhere.

  13. Automatic Energy Schemes for High Performance Applications

    SciTech Connect

    Sundriyal, Vaibhav

    2013-01-01

    Although high-performance computing traditionally focuses on the efficient execution of large-scale applications, both energy and power have become critical concerns when approaching exascale. Drastic increases in the power consumption of supercomputers affect significantly their operating costs and failure rates. In modern microprocessor architectures, equipped with dynamic voltage and frequency scaling (DVFS) and CPU clock modulation (throttling), the power consumption may be controlled in software. Additionally, network interconnect, such as Infiniband, may be exploited to maximize energy savings while the application performance loss and frequency switching overheads must be carefully balanced. This work first studies two important collective communication operations, all-to-all and allgather and proposes energy saving strategies on the per-call basis. Next, it targets point-to-point communications to group them into phases and apply frequency scaling to them to save energy by exploiting the architectural and communication stalls. Finally, it proposes an automatic runtime system which combines both collective and point-to-point communications into phases, and applies throttling to them apart from DVFS to maximize energy savings. The experimental results are presented for NAS parallel benchmark problems as well as for the realistic parallel electronic structure calculations performed by the widely used quantum chemistry package GAMESS. Close to the maximum energy savings were obtained with a substantially low performance loss on the given platform.

  14. Performance of the CMS High Level Trigger

    NASA Astrophysics Data System (ADS)

    Perrotta, Andrea

    2015-12-01

    The CMS experiment has been designed with a 2-level trigger system. The first level is implemented using custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increases in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. The increase in the number of interactions per bunch crossing, on average 25 in 2012, and expected to be around 40 in Run II, will be an additional complication. We present here the expected performance of the main triggers that will be used during the 2015 data taking campaign, paying particular attention to the new approaches that have been developed to cope with the challenges of the new run. This includes improvements in HLT electron and photon reconstruction as well as better performing muon triggers. We will also present the performance of the improved tracking and vertexing algorithms, discussing their impact on the b-tagging performance as well as on the jet and missing energy reconstruction.

  15. DOE High Performance Concentrator PV Project

    SciTech Connect

    McConnell, R.; Symko-Davies, M.

    2005-08-01

    Much in demand are next-generation photovoltaic (PV) technologies that can be used economically to make a large-scale impact on world electricity production. The U.S. Department of Energy (DOE) initiated the High-Performance Photovoltaic (HiPerf PV) Project to substantially increase the viability of PV for cost-competitive applications so that PV can contribute significantly to both our energy supply and environment. To accomplish such results, the National Center for Photovoltaics (NCPV) directs in-house and subcontracted research in high-performance polycrystalline thin-film and multijunction concentrator devices with the goal of enabling progress of high-efficiency technologies toward commercial-prototype products. We will describe the details of the subcontractor and in-house progress in exploring and accelerating pathways of III-V multijunction concentrator solar cells and systems toward their long-term goals. By 2020, we anticipate that this project will have demonstrated 33% system efficiency and a system price of $1.00/Wp for concentrator PV systems using III-V multijunction solar cells with efficiencies over 41%.

  16. High-performance computing in seismology

    SciTech Connect

    1996-09-01

    The scientific, technical, and economic importance of the issues discussed here presents a clear agenda for future research in computational seismology. In this way these problems will drive advances in high-performance computing in the field of seismology. There is a broad community that will benefit from this work, including the petroleum industry, research geophysicists, engineers concerned with seismic hazard mitigation, and governments charged with enforcing a comprehensive test ban treaty. These advances may also lead to new applications for seismological research. The recent application of high-resolution seismic imaging of the shallow subsurface for the environmental remediation industry is an example of this activity. This report makes the following recommendations: (1) focused efforts to develop validated documented software for seismological computations should be supported, with special emphasis on scalable algorithms for parallel processors; (2) the education of seismologists in high-performance computing technologies and methodologies should be improved; (3) collaborations between seismologists and computational scientists and engineers should be increased; (4) the infrastructure for archiving, disseminating, and processing large volumes of seismological data should be improved.

  17. High Power MPD Thruster Performance Measurements

    NASA Technical Reports Server (NTRS)

    LaPointe, Michael R.; Strzempkowski, Eugene; Pencil, Eric

    2004-01-01

    High power magnetoplasmadynamic (MPD) thrusters are being developed as cost effective propulsion systems for cargo transport to lunar and Mars bases, crewed missions to Mars and the outer planets, and robotic deep space exploration missions. Electromagnetic MPD thrusters have demonstrated, at the laboratory level, the ability to process megawatts of electrical power while providing significantly higher thrust densities than electrostatic electric propulsion systems. The ability to generate higher thrust densities permits a reduction in the number of thrusters required to perform a given mission, and alleviates the system complexity associated with multiple thruster arrays. The specific impulse of an MPD thruster can be optimized to meet given mission requirements, from a few thousand seconds with heavier gas propellants up to 10,000 seconds with hydrogen propellant. In support of programs envisioned by the NASA Office of Exploration Systems, Glenn Research Center is developing and testing quasi-steady MW-class MPD thrusters as a prelude to steady state high power thruster tests. This paper provides an overview of the GRC high power pulsed thruster test facility, and presents preliminary performance data for a quasi-steady baseline MPD thruster geometry.

  18. A high performance architecture for prolog

    SciTech Connect

    Dobry, T.

    1987-01-01

    Artificial Intelligence is entering the mainstream of computer applications and as techniques are developed and integrated into a wide variety of areas they are beginning to tax the processing power of conventional architecture. To meet this demand, specialized architectures providing support for the unique features of symbolic processing languages are emerging. The goal of the research presented here is to show that an architecture specialized for Prolog can achieve a ten-fold improvement in performance over conventional general-purpose architecture, and presents such an architecture for high performance execution of Prolog programs. The architecture is based on the abstract machine description known as the Warren Abstract Machine (WAM). The execution model of the WAM is described and extended to provide a complete Instruction Set Architecture (ISA) for Prolog known as the PLM. The ISA is then realized in a microarchitecture and finally in a hardware design.

  19. High-performance architecture for Prolog

    SciTech Connect

    Dobry, T.P.

    1987-01-01

    Artificial intelligence is entering the mainstream of computer applications and, as techniques are developed and integrated into a wide variety of areas, they are beginning to tax the processing power of conventional architectures. To meet this demand, specialized architectures providing support for the unique features of symbolic processing languages are emerging. The goal of the research presented here is to show that an architecture specialized for Prolog can achieve a tenfold improvement in performance over conventional, general-purpose architectures. This dissertation presents such an architecture for high performance execution of Prolog programs. The architecture is based on the abstract machine description introduced by David H.D. Warren known as the Warren Abstract Machine (WAM). The execution model of the WAM is described and extended to provide a complete Instruction Set Architecture (ISA) for Prolog known as the PLM. This ISA is then realized in a microarchitecture and finally in a hardware design.

  20. The high performance solar array GSR3

    NASA Astrophysics Data System (ADS)

    Mamode, A.; Bartevian, J.; Bastard, J. L.; Auffray, P.; Plagne, A.

    A foldout solar array for communication satellites was developed. A wing composed of 4 panels of 1.6 x 1.5 m and a Y-shaped yoke, and a wing with 3 panels of 2.4 x 2.4 m were made. End of life performance goal is greater than 35 W/kg with BSR 180 micron solar cells, and 50 W/kg using 50 micron BSFR cells. Analysis shows that all identified requirements can be covered with current skin made of open weave very high modulus carbon fiber; reinforcements of unidirectional carbon fiber; honeycomb in current section; hold-down inserts made of wound carbon fibers; titanium hinge fitting; and Kapton foil (25 or 50 micron thickness). Tests confirm performance predictions.

  1. Proven high-performance display solution

    NASA Astrophysics Data System (ADS)

    Johnson, Rick J.; Shaw, James E.; Mosier, Don; Liss, Raymond L.; Prouty, Todd D.; Davis, Josh; Marzen, Vincent P.; Deloy, Christian T.

    2002-08-01

    Rockwell Collins serves both the military and the commercial segments by exploiting the common elements of these applications. Rockwell Collins has created a liquid crystal display family capable of 100:1 contrast ratio, 40:1 high ambient contrast, 0.25% specular reflectance, 0.1% diffuse reflectance, enhanced color stability over +/- 55H, 0-30V field of view, 300 fL with 10K:1 dimming range, color NVIS B compliance while exceeding environmental performance requirements though ruggedization. In order to meet the full range of display requirements at a system level, all the components must be understood and managed to meet the end solution of the final system. This paper details Rockwell Collins' optical performance using an avionics grade panel, third generation custom compensation, and solid state backlight.

  2. High performance robotic traverse of desert terrain.

    SciTech Connect

    Whittaker, William

    2004-09-01

    This report presents tentative innovations to enable unmanned vehicle guidance for a class of off-road traverse at sustained speeds greater than 30 miles per hour. Analyses and field trials suggest that even greater navigation speeds might be achieved. The performance calls for innovation in mapping, perception, planning and inertial-referenced stabilization of components, hosted aboard capable locomotion. The innovations are motivated by the challenge of autonomous ground vehicle traverse of 250 miles of desert terrain in less than 10 hours, averaging 30 miles per hour. GPS coverage is assumed to be available with localized blackouts. Terrain and vegetation are assumed to be akin to that of the Mojave Desert. This terrain is interlaced with networks of unimproved roads and trails, which are a key to achieving the high performance mapping, planning and navigation that is presented here.

  3. Improving UV Resistance of High Performance Fibers

    NASA Astrophysics Data System (ADS)

    Hassanin, Ahmed

    High performance fibers are characterized by their superior properties compared to the traditional textile fibers. High strength fibers have high modules, high strength to weight ratio, high chemical resistance, and usually high temperature resistance. It is used in application where superior properties are needed such as bulletproof vests, ropes and cables, cut resistant products, load tendons for giant scientific balloons, fishing rods, tennis racket strings, parachute cords, adhesives and sealants, protective apparel and tire cords. Unfortunately, Ultraviolet (UV) radiation causes serious degradation to the most of high performance fibers. UV lights, either natural or artificial, cause organic compounds to decompose and degrade, because the energy of the photons of UV light is high enough to break chemical bonds causing chain scission. This work is aiming at achieving maximum protection of high performance fibers using sheathing approaches. The sheaths proposed are of lightweight to maintain the advantage of the high performance fiber that is the high strength to weight ratio. This study involves developing three different types of sheathing. The product of interest that need be protected from UV is braid from PBO. First approach is extruding a sheath from Low Density Polyethylene (LDPE) loaded with different rutile TiO2 % nanoparticles around the braid from the PBO. The results of this approach showed that LDPE sheath loaded with 10% TiO2 by weight achieved the highest protection compare to 0% and 5% TiO2. The protection here is judged by strength loss of PBO. This trend noticed in different weathering environments, where the sheathed samples were exposed to UV-VIS radiations in different weatheromter equipments as well as exposure to high altitude environment using NASA BRDL balloon. The second approach is focusing in developing a protective porous membrane from polyurethane loaded with rutile TiO2 nanoparticles. Membrane from polyurethane loaded with 4

  4. TMF ultra-high rate discharge performance

    SciTech Connect

    Nelson, B.

    1997-12-01

    BOLDER Technologies Corporation has developed a valve-regulated lead-acid product line termed Thin Metal Film (TMF{trademark}) technology. It is characterized by extremely thin plates and close plate spacing that facilitate high rates of charge and discharge with minimal temperature increases, at levels unachievable with other commercially-available battery technologies. This ultra-high rate performance makes TMF technology ideal for such applications as various types of engine start, high drain rate portable devices and high-current pulsing. Data are presented on very high current continuous and pulse discharges. Power and energy relationships at various discharge rates are explored and the fast-response characteristics of the BOLDER{reg_sign} cell are qualitatively defined. Short-duration recharge experiments will show that devices powered by BOLDER batteries can be in operation for more than 90% of an extended usage period with multiple fast recharges. The BOLDER cell is ideal for applications such as engine-start, a wide range of portable devices including power tools, hybrid electric vehicles and pulse-power devices. Applications such as this are very attractive, and are well served by TMF technology, but an area of great interest and excitement is ultrahigh power delivery in excess of 1 kW/kg.

  5. High performance channel injection sealant invention abstract

    NASA Technical Reports Server (NTRS)

    Rosser, R. W.; Basiulis, D. I.; Salisbury, D. P. (Inventor)

    1982-01-01

    High performance channel sealant is based on NASA patented cyano and diamidoximine-terminated perfluoroalkylene ether prepolymers that are thermally condensed and cross linked. The sealant contains asbestos and, in its preferred embodiments, Lithofrax, to lower its thermal expansion coefficient and a phenolic metal deactivator. Extensive evaluation shows the sealant is extremely resistant to thermal degradation with an onset point of 280 C. The materials have a volatile content of 0.18%, excellent flexibility, and adherence properties, and fuel resistance. No corrosibility to aluminum or titanium was observed.

  6. High-Performance Water-Iodinating Cartridge

    NASA Technical Reports Server (NTRS)

    Sauer, Richard; Gibbons, Randall E.; Flanagan, David T.

    1993-01-01

    High-performance cartridge contains bed of crystalline iodine iodinates water to near saturation in single pass. Cartridge includes stainless-steel housing equipped with inlet and outlet for water. Bed of iodine crystals divided into layers by polytetrafluoroethylene baffles. Holes made in baffles and positioned to maximize length of flow path through layers of iodine crystals. Resulting concentration of iodine biocidal; suppresses growth of microbes in stored water or disinfects contaminated equipment. Cartridge resists corrosion and can be stored wet. Reused several times before necessary to refill with fresh iodine crystals.

  7. High-performance neural networks. [Neural computers

    SciTech Connect

    Dress, W.B.

    1987-06-01

    The new Forth hardware architectures offer an intermediate solution to high-performance neural networks while the theory and programming details of neural networks for synthetic intelligence are developed. This approach has been used successfully to determine the parameters and run the resulting network for a synthetic insect consisting of a 200-node ''brain'' with 1760 interconnections. Both the insect's environment and its sensor input have thus far been simulated. However, the frequency-coded nature of the Browning network allows easy replacement of the simulated sensors by real-world counterparts.

  8. High performance thyratron driver with low jitter.

    PubMed

    Verma, Rishi; Lee, P; Springham, S V; Tan, T L; Rawat, R S

    2007-08-01

    We report the design and development of insulated gate bipolar junction transistor based high performance driver for operating thyratrons in grounded grid mode. With careful design, the driver meets the specification of trigger output pulse rise time less than 30 ns, jitter less than +/-1 ns, and time delay less than 160 ns. It produces a -600 V pulse of 500 ns duration (full width at half maximum) at repetition rate ranging from 1 Hz to 1.14 kHz. The developed module also facilitates heating and biasing units along with protection circuitry in one complete package.

  9. High Performance Piezoelectric Actuated Gimbal (HIERAX)

    SciTech Connect

    Charles Tschaggeny; Warren Jones; Eberhard Bamberg

    2007-04-01

    This paper presents a 3-axis gimbal whose three rotational axes are actuated by a novel drive system: linear piezoelectric motors whose linear output is converted to rotation by using drive disks. Advantages of this technology are: fast response, high accelerations, dither-free actuation and backlash-free positioning. The gimbal was developed to house a laser range finder for the purpose of tracking and guiding unmanned aerial vehicles during landing maneuvers. The tilt axis was built and the test results indicate excellent performance that meets design specifications.

  10. High Performance Polymer Memory and Its Formation

    DTIC Science & Technology

    2007-04-26

    Std. Z39.18 Final Report to AFOSR High Performance Polymer Memory Device and Its Formation Fund No.: FA9550-04-1-0215 Prepared by Prof. Yang Yang...polystyrene (PS). The metal nanoparticles were prepared by the two-phase 10-5 (b) 10𔄁Polymer film 1a CC , 10, Glass 1 -2 -1 0 1 2 3 4 5 Bias (V) Fig. I...such as copper pthalocyanine (CuPc), 24 ൢ zinc pthalocyanine (ZnPc), 27󈧠 tetracene, 29 and pentacene 30 have been used as donors combined with

  11. High-temperature testing of high performance fiber reinforced concrete

    NASA Astrophysics Data System (ADS)

    Fořt, Jan; Vejmelková, Eva; Pavlíková, Milena; Trník, Anton; Čítek, David; Kolísko, Jiří; Černý, Robert; Pavlík, Zbyšek

    2016-06-01

    The effect of high-temperature exposure on properties of High Performance Fiber Reinforced Concrete (HPFRC) is researched in the paper. At first, reference measurements are done on HPFRC samples without high-temperature loading. Then, the HPFRC samples are exposed to the temperatures of 200, 400, 600, 800, and 1000 °C. For the temperature loaded samples, measurement of residual mechanical and basic physical properties is done. Linear thermal expansion coefficient as function of temperature is accessed on the basis of measured thermal strain data. Additionally, simultaneous difference scanning calorimetry (DSC) and thermogravimetry (TG) analysis is performed in order to observe and explain material changes at elevated temperature. It is found that the applied high temperature loading significantly increases material porosity due to the physical, chemical and combined damage of material inner structure, and negatively affects also the mechanical strength. Linear thermal expansion coefficient exhibits significant dependence on temperature and changes of material structure. The obtained data will find use as input material parameters for modelling the damage of HPFRC structures exposed to the fire and high temperature action.

  12. Performance Evaluation of Emerging High Performance Computing Technologies using WRF

    NASA Astrophysics Data System (ADS)

    Newby, G. B.; Morton, D.

    2008-12-01

    The Arctic Region Supercomputing Center (ARSC) has evaluated multicore processors and other emerging processor technologies for a variety of high performance computing applications in the earth and space sciences, especially climate and weather applications. A flagship effort has been to assess dual core processor nodes on ARSC's Midnight supercomputer, in which two-socket systems were compared to eight-socket systems. Midnight is utilized for ARSC's twice-daily weather research and forecasting (WRF) model runs, available at weather.arsc.edu. Among other findings on Midnight, it was found that the Hypertransport system for interconnecting Opteron processors, memory, and other subsystems does not scale as well on eight-socket (sixteen processor) systems as well as two-socket (four processor) systems. A fundamental limitation is the cache snooping operation performed whenever a computational thread accesses main memory. This increases memory latency as the number of processor sockets increases. This is particularly noticeable on applications such as WRF that are primarily CPU-bound, versus applications that are bound by input/output or communication. The new Cray XT5 supercomputer at ARSC features quad core processors, and will host a variety of scaling experiments for WRF, CCSM4, and other models. Early results will be presented, including a series of WRF runs for Alaska with grid resolutions under 2km. ARSC will discuss a set of standardized test cases for the Alaska domain, similar to existing test cases for CONUS. These test cases will provide different configuration sizes and resolutions, suitable for single processors up to thousands. Beyond multi-core Opteron-based supercomputers, ARSC has examined WRF and other applications on additional emerging technologies. One such technology is the graphics processing unit, or GPU. The 9800-series nVidia GPU was evaluated with the cuBLAS software library. While in-socket GPUs might be forthcoming in the future, current

  13. Parallel Algebraic Multigrid Methods - High Performance Preconditioners

    SciTech Connect

    Yang, U M

    2004-11-11

    The development of high performance, massively parallel computers and the increasing demands of computationally challenging applications have necessitated the development of scalable solvers and preconditioners. One of the most effective ways to achieve scalability is the use of multigrid or multilevel techniques. Algebraic multigrid (AMG) is a very efficient algorithm for solving large problems on unstructured grids. While much of it can be parallelized in a straightforward way, some components of the classical algorithm, particularly the coarsening process and some of the most efficient smoothers, are highly sequential, and require new parallel approaches. This chapter presents the basic principles of AMG and gives an overview of various parallel implementations of AMG, including descriptions of parallel coarsening schemes and smoothers, some numerical results as well as references to existing software packages.

  14. High temperature furnace modeling and performance verifications

    NASA Technical Reports Server (NTRS)

    Smith, James E., Jr.

    1988-01-01

    Analytical, numerical and experimental studies were performed on two classes of high temperature materials processing furnaces. The research concentrates on a commercially available high temperature furnace using zirconia as the heating element and an arc furnace based on a ST International tube welder. The zirconia furnace was delivered and work is progressing on schedule. The work on the arc furnace was initially stalled due to the unavailability of the NASA prototype, which is actively being tested aboard the KC-135 experimental aircraft. A proposal was written and funded to purchase an additional arc welder to alleviate this problem. The ST International weld head and power supply were received and testing will begin in early November. The first 6 months of the grant are covered.

  15. High Performance Data Distribution for Scientific Community

    NASA Astrophysics Data System (ADS)

    Tirado, Juan M.; Higuero, Daniel; Carretero, Jesus

    2010-05-01

    Institutions such as NASA, ESA or JAXA find solutions to distribute data from their missions to the scientific community, and their long term archives. This is a complex problem, as it includes a vast amount of data, several geographically distributed archives, heterogeneous architectures with heterogeneous networks, and users spread around the world. We propose a novel architecture (HIDDRA) that solves this problem aiming to reduce user intervention in data acquisition and processing. HIDDRA is a modular system that provides a highly efficient parallel multiprotocol download engine, using a publish/subscribe policy which helps the final user to obtain data of interest transparently. Our system can deal simultaneously with multiple protocols (HTTP,HTTPS, FTP, GridFTP among others) to obtain the maximum bandwidth, reducing the workload in data server and increasing flexibility. It can also provide high reliability and fault tolerance, as several sources of data can be used to perform one file download. HIDDRA architecture can be arranged into a data distribution network deployed on several sites that can cooperate to provide former features. HIDDRA has been addressed by the 2009 e-IRG Report on Data Management as a promising initiative for data interoperability. Our first prototype has been evaluated in collaboration with the ESAC centre in Villafranca del Castillo (Spain) that shows a high scalability and performance, opening a wide spectrum of opportunities. Some preliminary results have been published in the Journal of Astrophysics and Space Science [1]. [1] D. Higuero, J.M. Tirado, J. Carretero, F. Félix, and A. de La Fuente. HIDDRA: a highly independent data distribution and retrieval architecture for space observation missions. Astrophysics and Space Science, 321(3):169-175, 2009

  16. Energy Efficient Graphene Based High Performance Capacitors.

    PubMed

    Bae, Joonwon; Lee, Chang-Soo; Kwon, Oh Seok

    2016-10-27

    Graphene (GRP) is an interesting class of nano-structured electronic materials for various cutting-edge applications. To date, extensive research activities have been performed on the investigation of diverse properties of GRP. The incorporation of this elegant material can be very lucrative in terms of practical applications in energy storage/conversion systems. Among various those systems, high performance electrochemical capacitors (ECs) have become popular due to the recent need for energy efficient and portable devices. Therefore, in this article, the application of GRP for capacitors is described succinctly. In particular, a concise summary on the previous research activities regarding GRP based capacitors is also covered extensively. It was revealed that a lot of secondary materials such as polymers and metal oxides have been introduced to improve the performance. Also, diverse devices have been combined with capacitors for better use. More importantly, recent patents related to the preparation and application of GRP based capacitors are also introduced briefly. This article can provide essential information for future study.

  17. High-performance laboratories and cleanrooms

    SciTech Connect

    Tschudi, William; Sartor, Dale; Mills, Evan; Xu, Tengfang

    2002-07-01

    The California Energy Commission sponsored this roadmap to guide energy efficiency research and deployment for high performance cleanrooms and laboratories. Industries and institutions utilizing these building types (termed high-tech buildings) have played an important part in the vitality of the California economy. This roadmap's key objective to present a multi-year agenda to prioritize and coordinate research efforts. It also addresses delivery mechanisms to get the research products into the market. Because of the importance to the California economy, it is appropriate and important for California to take the lead in assessing the energy efficiency research needs, opportunities, and priorities for this market. In addition to the importance to California's economy, energy demand for this market segment is large and growing (estimated at 9400 GWH for 1996, Mills et al. 1996). With their 24hr. continuous operation, high tech facilities are a major contributor to the peak electrical demand. Laboratories and cleanrooms constitute the high tech building market, and although each building type has its unique features, they are similar in that they are extremely energy intensive, involve special environmental considerations, have very high ventilation requirements, and are subject to regulations--primarily safety driven--that tend to have adverse energy implications. High-tech buildings have largely been overlooked in past energy efficiency research. Many industries and institutions utilize laboratories and cleanrooms. As illustrated, there are many industries operating cleanrooms in California. These include semiconductor manufacturing, semiconductor suppliers, pharmaceutical, biotechnology, disk drive manufacturing, flat panel displays, automotive, aerospace, food, hospitals, medical devices, universities, and federal research facilities.

  18. High-performance computing for airborne applications

    SciTech Connect

    Quinn, Heather M; Manuzzato, Andrea; Fairbanks, Tom; Dallmann, Nicholas; Desgeorges, Rose

    2010-06-28

    Recently, there has been attempts to move common satellite tasks to unmanned aerial vehicles (UAVs). UAVs are significantly cheaper to buy than satellites and easier to deploy on an as-needed basis. The more benign radiation environment also allows for an aggressive adoption of state-of-the-art commercial computational devices, which increases the amount of data that can be collected. There are a number of commercial computing devices currently available that are well-suited to high-performance computing. These devices range from specialized computational devices, such as field-programmable gate arrays (FPGAs) and digital signal processors (DSPs), to traditional computing platforms, such as microprocessors. Even though the radiation environment is relatively benign, these devices could be susceptible to single-event effects. In this paper, we will present radiation data for high-performance computing devices in a accelerated neutron environment. These devices include a multi-core digital signal processor, two field-programmable gate arrays, and a microprocessor. From these results, we found that all of these devices are suitable for many airplane environments without reliability problems.

  19. High Performance Computing CFRD -- Final Technial Report

    SciTech Connect

    Hope Forsmann; Kurt Hamman

    2003-01-01

    The Bechtel Waste Treatment Project (WTP), located in Richland, WA, is comprised of many processes containing complex physics. Accurate analyses of the underlying physics of these processes is needed to reduce the amount of added costs during and after construction that are due to unknown process behavior. The WTP will have tight operating margins in order to complete the treatment of the waste on schedule. The combination of tight operating constraints coupled with complex physical processes requires analysis methods that are more accurate than traditional approaches. This study is focused specifically on multidimensional computer aided solutions. There are many skills and tools required to solve engineering problems. Many physical processes are governed by nonlinear partial differential equations. These governing equations have few, if any, closed form solutions. Past and present solution methods require assumptions to reduce these equations to solvable forms. Computational methods take the governing equations and solve them directly on a computational grid. This ability to approach the equations in their exact form reduces the number of assumptions that must be made. This approach increases the accuracy of the solution and its applicability to the problem at hand. Recent advances in computer technology have allowed computer simulations to become an essential tool for problem solving. In order to perform computer simulations as quickly and accurately as possible, both hardware and software must be evaluated. With regards to hardware, the average consumer personal computers (PCs) are not configured for optimal scientific use. Only a few vendors create high performance computers to satisfy engineering needs. Software must be optimized for quick and accurate execution. Operating systems must utilize the hardware efficiently while supplying the software with seamless access to the computer’s resources. From the perspective of Bechtel Corporation and the Idaho

  20. SISYPHUS: A high performance seismic inversion factory

    NASA Astrophysics Data System (ADS)

    Gokhberg, Alexey; Simutė, Saulė; Boehm, Christian; Fichtner, Andreas

    2016-04-01

    In the recent years the massively parallel high performance computers became the standard instruments for solving the forward and inverse problems in seismology. The respective software packages dedicated to forward and inverse waveform modelling specially designed for such computers (SPECFEM3D, SES3D) became mature and widely available. These packages achieve significant computational performance and provide researchers with an opportunity to solve problems of bigger size at higher resolution within a shorter time. However, a typical seismic inversion process contains various activities that are beyond the common solver functionality. They include management of information on seismic events and stations, 3D models, observed and synthetic seismograms, pre-processing of the observed signals, computation of misfits and adjoint sources, minimization of misfits, and process workflow management. These activities are time consuming, seldom sufficiently automated, and therefore represent a bottleneck that can substantially offset performance benefits provided by even the most powerful modern supercomputers. Furthermore, a typical system architecture of modern supercomputing platforms is oriented towards the maximum computational performance and provides limited standard facilities for automation of the supporting activities. We present a prototype solution that automates all aspects of the seismic inversion process and is tuned for the modern massively parallel high performance computing systems. We address several major aspects of the solution architecture, which include (1) design of an inversion state database for tracing all relevant aspects of the entire solution process, (2) design of an extensible workflow management framework, (3) integration with wave propagation solvers, (4) integration with optimization packages, (5) computation of misfits and adjoint sources, and (6) process monitoring. The inversion state database represents a hierarchical structure with

  1. High performance electrospinning system for fabricating highly uniform polymer nanofibers

    NASA Astrophysics Data System (ADS)

    Munir, Muhammad Miftahul; Iskandar, Ferry; Khairurrijal, Okuyama, Kikuo

    2009-02-01

    A high performance electrospinning system has been successfully developed for production of highly uniform polymer nanofibers. The electrospinning system employed a proportional-integral-derivative control action to maintain a constant current during the production of polyvinyl acetate (PVAc) nanofibers from a precursor solution prepared by dissolution of the PVAc powder in dimethyl formamide so that high uniformity of the nanofibers was achieved. It was found that the cone jet length observed at the end of the needle during the injection of the precursor solution and the average diameter of the nanofibers decreased with decreasing Q /I, where Q is the flow rate of the precursor solution of the nanofibers and I is the current flowing through the electrospinning system. A power law obtained from the relation between the average diameter and Q /I is in accordance with the theoretical model.

  2. PREFACE: High Performance Computing Symposium 2011

    NASA Astrophysics Data System (ADS)

    Talon, Suzanne; Mousseau, Normand; Peslherbe, Gilles; Bertrand, François; Gauthier, Pierre; Kadem, Lyes; Moitessier, Nicolas; Rouleau, Guy; Wittig, Rod

    2012-02-01

    HPCS (High Performance Computing Symposium) is a multidisciplinary conference that focuses on research involving High Performance Computing and its application. Attended by Canadian and international experts and renowned researchers in the sciences, all areas of engineering, the applied sciences, medicine and life sciences, mathematics, the humanities and social sciences, it is Canada's pre-eminent forum for HPC. The 25th edition was held in Montréal, at the Université du Québec à Montréal, from 15-17 June and focused on HPC in Medical Science. The conference was preceded by tutorials held at Concordia University, where 56 participants learned about HPC best practices, GPU computing, parallel computing, debugging and a number of high-level languages. 274 participants from six countries attended the main conference, which involved 11 invited and 37 contributed oral presentations, 33 posters, and an exhibit hall with 16 booths from our sponsors. The work that follows is a collection of papers presented at the conference covering HPC topics ranging from computer science to bioinformatics. They are divided here into four sections: HPC in Engineering, Physics and Materials Science, HPC in Medical Science, HPC Enabling to Explore our World and New Algorithms for HPC. We would once more like to thank the participants and invited speakers, the members of the Scientific Committee, the referees who spent time reviewing the papers and our invaluable sponsors. To hear the invited talks and learn about 25 years of HPC development in Canada visit the Symposium website: http://2011.hpcs.ca/lang/en/conference/keynote-speakers/ Enjoy the excellent papers that follow, and we look forward to seeing you in Vancouver for HPCS 2012! Gilles Peslherbe Chair of the Scientific Committee Normand Mousseau Co-Chair of HPCS 2011 Suzanne Talon Chair of the Organizing Committee UQAM Sponsors The PDF also contains photographs from the conference banquet.

  3. Study of High-Performance Coronagraphic Techniques

    NASA Astrophysics Data System (ADS)

    Tolls, Volker; Aziz, M. J.; Gonsalves, R. A.; Korzennik, S. G.; Labeyrie, A.; Lyon, R. G.; Melnick, G. J.; Somerstein, S.; Vasudevan, G.; Woodruff, R. A.

    2007-05-01

    We will provide a progress report about our study of high-performance coronagraphic techniques. At SAO we have set up a testbed to test coronagraphic masks and to demonstrate Labeyrie's multi-step speckle reduction technique. This technique expands the general concept of a coronagraph by incorporating a speckle corrector (phase or amplitude) and second occulter for speckle light suppression. The testbed consists of a coronagraph with high precision optics (2 inch spherical mirrors with lambda/1000 surface quality), lasers simulating the host star and the planet, and a single Labeyrie correction stage with a MEMS deformable mirror (DM) for the phase correction. The correction function is derived from images taken in- and slightly out-of-focus using phase diversity. The testbed is operational awaiting coronagraphic masks. The testbed control software for operating the CCD camera, the translation stage that moves the camera in- and out-of-focus, the wavefront recovery (phase diversity) module, and DM control is under development. We are also developing coronagraphic masks in collaboration with Harvard University and Lockheed Martin Corp. (LMCO). The development at Harvard utilizes a focused ion beam system to mill masks out of absorber material and the LMCO approach uses patterns of dots to achieve the desired mask performance. We will present results of both investigations including test results from the first generation of LMCO masks obtained with our high-precision mask scanner. This work was supported by NASA through grant NNG04GC57G, through SAO IR&D funding, and by Harvard University through the Research Experience for Undergraduate Program of Harvard's Materials Science and Engineering Center. Central facilities were provided by Harvard's Center for Nanoscale Systems.

  4. Scalable resource management in high performance computers.

    SciTech Connect

    Frachtenberg, E.; Petrini, F.; Fernandez Peinador, J.; Coll, S.

    2002-01-01

    Clusters of workstations have emerged as an important platform for building cost-effective, scalable and highly-available computers. Although many hardware solutions are available today, the largest challenge in making large-scale clusters usable lies in the system software. In this paper we present STORM, a resource management tool designed to provide scalability, low overhead and the flexibility necessary to efficiently support and analyze a wide range of job scheduling algorithms. STORM achieves these feats by closely integrating the management daemons with the low-level features that are common in state-of-the-art high-performance system area networks. The architecture of STORM is based on three main technical innovations. First, a sizable part of the scheduler runs in the thread processor located on the network interface. Second, we use hardware collectives that are highly scalable both for implementing control heartbeats and to distribute the binary of a parallel job in near-constant time, irrespective of job and machine sizes. Third, we use an I/O bypass protocol that allows fast data movements from the file system to the communication buffers in the network interface and vice versa. The experimental results show that STORM can launch a job with a binary of 12MB on a 64 processor/32 node cluster in less than 0.25 sec on an empty network, in less than 0.45 sec when all the processors are busy computing other jobs, and in less than 0.65 sec when the network is flooded with a background traffic. This paper provides experimental and analytical evidence that these results scale to a much larger number of nodes. To the best of our knowledge, STORM is at least two orders of magnitude faster than existing production schedulers in launching jobs, performing resource management tasks and gang scheduling.

  5. High performance visual display for HENP detectors

    NASA Astrophysics Data System (ADS)

    McGuigan, Michael; Smith, Gordon; Spiletic, John; Fine, Valeri; Nevski, Pavel

    2001-08-01

    A high end visual display for High Energy Nuclear Physics (HENP) detectors is necessary because of the sheer size and complexity of the detector. For BNL this display will be of special interest because of STAR and ATLAS. To load, rotate, query, and debug simulation code with a modern detector simply takes too long even on a powerful work station. To visualize the HENP detectors with maximal performance we have developed software with the following characteristics. We develop a visual display of HENP detectors on BNL multiprocessor visualization server at multiple level of detail. We work with general and generic detector framework consistent with ROOT, GAUDI etc, to avoid conflicting with the many graphic development groups associated with specific detectors like STAR and ATLAS. We develop advanced OpenGL features such as transparency and polarized stereoscopy. We enable collaborative viewing of detector and events by directly running the analysis in BNL stereoscopic theatre. We construct enhanced interactive control, including the ability to slice, search and mark areas of the detector. We incorporate the ability to make a high quality still image of a view of the detector and the ability to generate animations and a fly through of the detector and output these to MPEG or VRML models. We develop data compression hardware and software so that remote interactive visualization will be possible among dispersed collaborators. We obtain real time visual display for events accumulated during simulations.

  6. Low-Cost High-Performance MRI

    PubMed Central

    Sarracanie, Mathieu; LaPierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-01-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5–3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices. PMID:26469756

  7. Low-Cost High-Performance MRI

    NASA Astrophysics Data System (ADS)

    Sarracanie, Mathieu; Lapierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-10-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices.

  8. Thermal interface pastes nanostructured for high performance

    NASA Astrophysics Data System (ADS)

    Lin, Chuangang

    Thermal interface materials in the form of pastes are needed to improve thermal contacts, such as that between a microprocessor and a heat sink of a computer. High-performance and low-cost thermal pastes have been developed in this dissertation by using polyol esters as the vehicle and various nanoscale solid components. The proportion of a solid component needs to be optimized, as an excessive amount degrades the performance, due to the increase in the bond line thickness. The optimum solid volume fraction tends to be lower when the mating surfaces are smoother, and higher when the thermal conductivity is higher. Both a low bond line thickness and a high thermal conductivity help the performance. When the surfaces are smooth, a low bond line thickness can be even more important than a high thermal conductivity, as shown by the outstanding performance of the nanoclay paste of low thermal conductivity in the smooth case (0.009 mum), with the bond line thickness less than 1 mum, as enabled by low storage modulus G', low loss modulus G" and high tan delta. However, for rough surfaces, the thermal conductivity is important. The rheology affects the bond line thickness, but it does not correlate well with the performance. This study found that the structure of carbon black is an important parameter that governs the effectiveness of a carbon black for use in a thermal paste. By using a carbon black with a lower structure (i.e., a lower DBP value), a thermal paste that is more effective than the previously reported carbon black paste was obtained. Graphite nanoplatelet (GNP) was found to be comparable in effectiveness to carbon black (CB) pastes for rough surfaces, but it is less effective for smooth surfaces. At the same filler volume fraction, GNP gives higher thermal conductivity than carbon black paste. At the same pressure, GNP gives higher bond line thickness than CB (Tokai or Cabot). The effectiveness of GNP is limited, due to the high bond line thickness. A

  9. Integrating advanced facades into high performance buildings

    SciTech Connect

    Selkowitz, Stephen E.

    2001-05-01

    Glass is a remarkable material but its functionality is significantly enhanced when it is processed or altered to provide added intrinsic capabilities. The overall performance of glass elements in a building can be further enhanced when they are designed to be part of a complete facade system. Finally the facade system delivers the greatest performance to the building owner and occupants when it becomes an essential element of a fully integrated building design. This presentation examines the growing interest in incorporating advanced glazing elements into more comprehensive facade and building systems in a manner that increases comfort, productivity and amenity for occupants, reduces operating costs for building owners, and contributes to improving the health of the planet by reducing overall energy use and negative environmental impacts. We explore the role of glazing systems in dynamic and responsive facades that provide the following functionality: Enhanced sun protection and cooling load control while improving thermal comfort and providing most of the light needed with daylighting; Enhanced air quality and reduced cooling loads using natural ventilation schemes employing the facade as an active air control element; Reduced operating costs by minimizing lighting, cooling and heating energy use by optimizing the daylighting-thermal tradeoffs; Net positive contributions to the energy balance of the building using integrated photovoltaic systems; Improved indoor environments leading to enhanced occupant health, comfort and performance. In addressing these issues facade system solutions must, of course, respect the constraints of latitude, location, solar orientation, acoustics, earthquake and fire safety, etc. Since climate and occupant needs are dynamic variables, in a high performance building the facade solution have the capacity to respond and adapt to these variable exterior conditions and to changing occupant needs. This responsive performance capability

  10. Optics of high-performance electron microscopes.

    PubMed

    Rose, H H

    2008-01-01

    During recent years, the theory of charged particle optics together with advances in fabrication tolerances and experimental techniques has lead to very significant advances in high-performance electron microscopes. Here, we will describe which theoretical tools, inventions and designs have driven this development. We cover the basic theory of higher-order electron optics and of image formation in electron microscopes. This leads to a description of different methods to correct aberrations by multipole fields and to a discussion of the most advanced design that take advantage of these techniques. The theory of electron mirrors is developed and it is shown how this can be used to correct aberrations and to design energy filters. Finally, different types of energy filters are described.

  11. High performance computing applications in neurobiological research

    NASA Technical Reports Server (NTRS)

    Ross, Muriel D.; Cheng, Rei; Doshay, David G.; Linton, Samuel W.; Montgomery, Kevin; Parnas, Bruce R.

    1994-01-01

    The human nervous system is a massively parallel processor of information. The vast numbers of neurons, synapses and circuits is daunting to those seeking to understand the neural basis of consciousness and intellect. Pervading obstacles are lack of knowledge of the detailed, three-dimensional (3-D) organization of even a simple neural system and the paucity of large scale, biologically relevant computer simulations. We use high performance graphics workstations and supercomputers to study the 3-D organization of gravity sensors as a prototype architecture foreshadowing more complex systems. Scaled-down simulations run on a Silicon Graphics workstation and scale-up, three-dimensional versions run on the Cray Y-MP and CM5 supercomputers.

  12. High performance stepper motors for space mechanisms

    NASA Astrophysics Data System (ADS)

    Sega, Patrick; Estevenon, Christine

    1995-05-01

    Hybrid stepper motors are very well adapted to high performance space mechanisms. They are very simple to operate and are often used for accurate positioning and for smooth rotations. In order to fulfill these requirements, the motor torque, its harmonic content, and the magnetic parasitic torque have to be properly designed. Only finite element computations can provide enough accuracy to determine the toothed structures' magnetic permeance, whose derivative function leads to the torque. It is then possible to design motors with a maximum torque capability or with the most reduced torque harmonic content (less than 3 percent of fundamental). These later motors are dedicated to applications where a microstep or a synchronous mode is selected for minimal dynamic disturbances. In every case, the capability to convert electrical power into torque is much higher than on DC brushless motors.

  13. High-performance nanostructured MR contrast probes

    PubMed Central

    Hu, Fengqin; Joshi, Hrushikesh M.; Dravid, Vinayak P.; Meade, Thomas J.

    2011-01-01

    Magnetic resonance imaging (MRI) has become a powerful technique in biological molecular imaging and clinical diagnosis. With the rapid progress in nanoscale science and technology, nanostructure-based MR contrast agents are undergoing rapid development. This is in part due to the tuneable magnetic and cellular uptake properties, large surface area for conjugation and favourable biodistribution. In this review, we describe our recent progress in the development of high-performance nanostructured MR contrast agents. Specifically, we report on Gd-enriched nanostructured probes that exhibit T1 MR contrast and superparamagnetic Fe3O4 and CoFe2O4 nanostructures that display T2 MR contrast enhancement. The effects of nanostructure size, shape, assembly and surface modification on relaxivity are described. The potential of these contrast agents for in vitro and in vivo MR imaging with respect to colloidal stability under physiological conditions, biocompatibility, and surface functionality are also evaluated. PMID:20694208

  14. Optics of high-performance electron microscopes*

    PubMed Central

    Rose, H H

    2008-01-01

    During recent years, the theory of charged particle optics together with advances in fabrication tolerances and experimental techniques has lead to very significant advances in high-performance electron microscopes. Here, we will describe which theoretical tools, inventions and designs have driven this development. We cover the basic theory of higher-order electron optics and of image formation in electron microscopes. This leads to a description of different methods to correct aberrations by multipole fields and to a discussion of the most advanced design that take advantage of these techniques. The theory of electron mirrors is developed and it is shown how this can be used to correct aberrations and to design energy filters. Finally, different types of energy filters are described. PMID:27877933

  15. High performance stepper motors for space mechanisms

    NASA Technical Reports Server (NTRS)

    Sega, Patrick; Estevenon, Christine

    1995-01-01

    Hybrid stepper motors are very well adapted to high performance space mechanisms. They are very simple to operate and are often used for accurate positioning and for smooth rotations. In order to fulfill these requirements, the motor torque, its harmonic content, and the magnetic parasitic torque have to be properly designed. Only finite element computations can provide enough accuracy to determine the toothed structures' magnetic permeance, whose derivative function leads to the torque. It is then possible to design motors with a maximum torque capability or with the most reduced torque harmonic content (less than 3 percent of fundamental). These later motors are dedicated to applications where a microstep or a synchronous mode is selected for minimal dynamic disturbances. In every case, the capability to convert electrical power into torque is much higher than on DC brushless motors.

  16. Study of High Performance Coronagraphic Techniques

    NASA Technical Reports Server (NTRS)

    Crane, Phil (Technical Monitor); Tolls, Volker

    2004-01-01

    The goal of the Study of High Performance Coronagraphic Techniques project (called CoronaTech) is: 1) to verify the Labeyrie multi-step speckle reduction method and 2) to develop new techniques to manufacture soft-edge occulter masks preferably with Gaussian absorption profile. In a coronagraph, the light from a bright host star which is centered on the optical axis in the image plane is blocked by an occulter centered on the optical axis while the light from a planet passes the occulter (the planet has a certain minimal distance from the optical axis). Unfortunately, stray light originating in the telescope and subsequent optical elements is not completely blocked causing a so-called speckle pattern in the image plane of the coronagraph limiting the sensitivity of the system. The sensitivity can be increased significantly by reducing the amount of speckle light. The Labeyrie multi-step speckle reduction method implements one (or more) phase correction steps to suppress the unwanted speckle light. In each step, the stray light is rephased and then blocked with an additional occulter which affects the planet light (or other companion) only slightly. Since the suppression is still not complete, a series of steps is required in order to achieve significant suppression. The second part of the project is the development of soft-edge occulters. Simulations have shown that soft-edge occulters show better performance in coronagraphs than hard-edge occulters. In order to utilize the performance gain of soft-edge occulters. fabrication methods have to be developed to manufacture these occulters according to the specification set forth by the sensitivity requirements of the coronagraph.

  17. High-Performance Monopropellants and Catalysts Evaluated

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.

    2004-01-01

    The NASA Glenn Research Center is sponsoring efforts to develop advanced monopropellant technology. The focus has been on monopropellant formulations composed of an aqueous solution of hydroxylammonium nitrate (HAN) and a fuel component. HAN-based monopropellants do not have a toxic vapor and do not need the extraordinary procedures for storage, handling, and disposal required of hydrazine (N2H4). Generically, HAN-based monopropellants are denser and have lower freezing points than N2H4. The performance of HAN-based monopropellants depends on the selection of fuel, the HAN-to-fuel ratio, and the amount of water in the formulation. HAN-based monopropellants are not seen as a replacement for N2H4 per se, but rather as a propulsion option in their own right. For example, HAN-based monopropellants would prove beneficial to the orbit insertion of small, power-limited satellites because of this propellant's high performance (reduced system mass), high density (reduced system volume), and low freezing point (elimination of tank and line heaters). Under a Glenn-contracted effort, Aerojet Redmond Rocket Center conducted testing to provide the foundation for the development of monopropellant thrusters with an I(sub sp) goal of 250 sec. A modular, workhorse reactor (representative of a 1-lbf thruster) was used to evaluate HAN formulations with catalyst materials. Stoichiometric, oxygen-rich, and fuelrich formulations of HAN-methanol and HAN-tris(aminoethyl)amine trinitrate were tested to investigate the effects of stoichiometry on combustion behavior. Aerojet found that fuelrich formulations degrade the catalyst and reactor faster than oxygen-rich and stoichiometric formulations do. A HAN-methanol formulation with a theoretical Isp of 269 sec (designated HAN269MEO) was selected as the baseline. With a combustion efficiency of at least 93 percent demonstrated for HAN-based monopropellants, HAN269MEO will meet the I(sub sp) 250 sec goal.

  18. The design of high-performance gliders

    NASA Technical Reports Server (NTRS)

    Mueller, B.; Heuermann, V.

    1985-01-01

    A high-performance glider is defined as a glider which has been designed to carry the pilot in a minimum of time a given distance, taking into account conditions which are as conveniently as possible. The present investigation has the objective to show approaches for enhancing the cross-country flight cruising speed, giving attention to the difficulties which the design engineer will have to overcome. The characteristics of the cross-country flight and their relation to the cruising speed are discussed, and a description is provided of mathematical expressions concerning the cruising speed, the sinking speed, and the optimum gliding speed. The effect of aspect ratio and wing loading on the cruising speed is illustrated with the aid of a graph. Trends in glider development are explored, taking into consideration the design of laminar profiles, the reduction of profile-related drag by plain flaps, and the variation of wing loading during the flight. A number of suggestions are made for obtaining gliders with improved performance.

  19. High performance zinc air fuel cell stack

    NASA Astrophysics Data System (ADS)

    Pei, Pucheng; Ma, Ze; Wang, Keliang; Wang, Xizhong; Song, Mancun; Xu, Huachi

    2014-03-01

    A zinc air fuel cell (ZAFC) stack with inexpensive manganese dioxide (MnO2) as the catalyst is designed, in which the circulation flowing potassium hydroxide (KOH) electrolyte carries the reaction product away and acts as a coolant. Experiments are carried out to investigate the characteristics of polarization, constant current discharge and dynamic response, as well as the factors affecting the performance and uniformity of individual cells in the stack. The results reveal that the peak power density can be as high as 435 mW cm-2 according to the area of the air cathode sheet, and the influence factors on cell performance and uniformity are cell locations, filled state of zinc pellets, contact resistance, flow rates of electrolyte and air. It is also shown that the time needed for voltages to reach steady state and that for current step-up or current step-down are both in milliseconds, indicating the ZAFC can be excellently applied to vehicles with rapid dynamic response demands.

  20. Ultra High Performance, Highly Reliable, Numeric Intensive Processors and Systems

    DTIC Science & Technology

    1989-10-01

    to design high-performance DSP/IP systems using either off-the-shelf components or application specific integrated circuitry [ ASIC ]. -9 - HSDAL . ARO...are the chirp-z transform ( CZT ) [13] and (Rader’s) Prime Factor Transform (PFT) [11]. The RNS/ CZT is being studied by a group a MITRE [14] and is given...PFT RNS/CRNS/QRNS implementation has dynamic range requirements on the order of NQ2 (vs NQ4 for the CZT and much higher for the FFT). Therefore, the

  1. High performance internal reforming unit for high temperature fuel cells

    DOEpatents

    Ma, Zhiwen; Venkataraman, Ramakrishnan; Novacco, Lawrence J.

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  2. High Power Flex-Propellant Arcjet Performance

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.

    2011-01-01

    implied nearly frozen flow in the nozzle and yielded performance ranges of 800-1100 sec for hydrogen and 400-600 sec for ammonia. Inferred thrust-to-power ratios were in the range of 30-10 lbf/MWe for hydrogen and 60-20 lbf/MWe for ammonia. Successful completion of this test series represents a fundamental milestone in the progression of high power arcjet technology, and it is hoped that the results may serve as a reliable touchstone for the future development of MW-class regeneratively-cooled flex-propellant plasma rockets.

  3. NCI's Transdisciplinary High Performance Scientific Data Platform

    NASA Astrophysics Data System (ADS)

    Evans, Ben; Antony, Joseph; Bastrakova, Irina; Car, Nicholas; Cox, Simon; Druken, Kelsey; Evans, Bradley; Fraser, Ryan; Ip, Alex; Kemp, Carina; King, Edward; Minchin, Stuart; Larraondo, Pablo; Pugh, Tim; Richards, Clare; Santana, Fabiana; Smillie, Jon; Trenham, Claire; Wang, Jingbo; Wyborn, Lesley

    2016-04-01

    The Australian National Computational Infrastructure (NCI) manages Earth Systems data collections sourced from several domains and organisations onto a single High Performance Data (HPD) Node to further Australia's national priority research and innovation agenda. The NCI HPD Node has rapidly established its value, currently managing over 10 PBytes of datasets from collections that span a wide range of disciplines including climate, weather, environment, geoscience, geophysics, water resources and social sciences. Importantly, in order to facilitate broad user uptake, maximise reuse and enable transdisciplinary access through software and standardised interfaces, the datasets, associated information systems and processes have been incorporated into the design and operation of a unified platform that NCI has called, the National Environmental Research Data Interoperability Platform (NERDIP). The key goal of the NERDIP is to regularise data access so that it is easily discoverable, interoperable for different domains and enabled for high performance methods. It adopts and implements international standards and data conventions, and promotes scientific integrity within a high performance computing and data analysis environment. NCI has established a rich and flexible computing environment to access to this data, through the NCI supercomputer; a private cloud that supports both domain focused virtual laboratories and in-common interactive analysis interfaces; as well as remotely through scalable data services. Data collections of this importance must be managed with careful consideration of both their current use and the needs of the end-communities, as well as its future potential use, such as transitioning to more advanced software and improved methods. It is therefore critical that the data platform is both well-managed and trusted for stable production use (including transparency and reproducibility), agile enough to incorporate new technological advances and

  4. High performance BGMI circuit for VLWIR FPAs

    NASA Astrophysics Data System (ADS)

    Hao, Li-chao; Chen, Hong-lei; Huang, Ai-bo; Zhang, Jun-ling; Ding, Rui-jun

    2013-09-01

    An improved CMOS readout integrated circuit (ROIC) for N-on-P very long wavelength (VLWIR) detectors is designed, which has the ability to operate with a simple background suppression. It increases the integration time and the signal-to-noise ratio (SNR) of image data. A buffered gate modulation input (BGMI) cell as input circuit provides a low input resistance, high injection efficiency, and precise biasing voltage to the photodiode. By theoretically analyzing the characteristic parameters of MOS device at low temperature, a high gain's feedback amplifier is devised which using a differential stage to provide the inverting gain to improve linearity and to provide tight control of the detector bias. The final chip is fabricated with HHNEC 0.35um 1P4M process technology. The measurement results of the fabricated readout chip under 50K have successfully verified both readout function and performance improvement. With the 5.0V power supply, ROIC provides the output dynamic range over 2.5V. At the same time, the total power dissipation is less than 200mW, and the maximum readout speed is more than 2.5MHz.

  5. New high performance Si for optical devices

    NASA Astrophysics Data System (ADS)

    Tenma, T.; Matsuzaka, M.; Sako, R.; Takase, K.; Chiba, K.

    2016-05-01

    Against the backdrop of a growing demand in the areas of smart buildings, security, vehicle installation, and other applications, the market for far infrared cameras is expected to grow significantly in the future. However, since germanium (Ge) and chalcogenide glass, which have been used as the lens materials of far infrared cameras, are very expensive or highly toxic, there are some problems supporting the growing demand. We have therefore focused attention on silicon, which is inexpensive and less toxic. Although silicon has been used as a lens material of far infrared cameras, there are some problems remaining to be solved: Cz silicon is inexpensive but delivers low transmittance, and Fz silicon delivers sufficient transmittance but is expensive. We have developed New Cz silicon, which delivers high transmittance as Fz silicon does, and is inexpensive as conventional Cz silicon is. We have already started its sample work at both companies in Japan and overseas and have obtained excellent performance results. Mass production is scheduled to start in this fiscal year.

  6. High-performance computers for unmanned vehicles

    NASA Astrophysics Data System (ADS)

    Toms, David; Ettinger, Gil J.

    2005-10-01

    The present trend of increasing functionality onboard unmanned vehicles is made possible by rapid advances in high-performance computers (HPCs). An HPC is characterized by very high computational capability (100s of billions of operations per second) contained in lightweight, rugged, low-power packages. HPCs are critical to the processing of sensor data onboard these vehicles. Operations such as radar image formation, target tracking, target recognition, signal intelligence signature collection and analysis, electro-optic image compression, and onboard data exploitation are provided by these machines. The net effect of an HPC is to minimize communication bandwidth requirements and maximize mission flexibility. This paper focuses on new and emerging technologies in the HPC market. Emerging capabilities include new lightweight, low-power computing systems: multi-mission computing (using a common computer to support several sensors); onboard data exploitation; and large image data storage capacities. These new capabilities will enable an entirely new generation of deployed capabilities at reduced cost. New software tools and architectures available to unmanned vehicle developers will enable them to rapidly develop optimum solutions with maximum productivity and return on investment. These new technologies effectively open the trade space for unmanned vehicle designers.

  7. High Performance Anion Chromatography of Gadolinium Chelates.

    PubMed

    Hajós, Peter; Lukács, Diana; Farsang, Evelin; Horváth, Krisztian

    2016-11-01

    High performance anion chromatography (HPIC) method to separate ionic Gd chelates, [Formula: see text], [Formula: see text], [Formula: see text] and free matrix anions was developed. At alkaline pHs, polydentate complexing agents such as ethylene-diamine-tetraacetate, diethylene-triamine pentaacetate and trans-1,2-diamine-cyclohexane-tetraacetate tend to form stable Gd chelate anions and can be separated by anion exchange. Separations were studied in the simple isocratic chromatographic run over the wide range of pH and concentration of carbonate eluent using suppressed conductivity detection. The ion exchange and complex forming equilibria were quantitatively described and demonstrated in order to understand major factors in the control of selectivity of Gd chelates. Parameters of optimized resolution between concurrent ions were presented on a 3D resolution surface. The applicability of the developed method is represented by the simultaneous analysis of Gd chelates and organic/inorganic anions. Inductively coupled plasma atomic emission spectroscopy  (ICP-AES) analysis was used for confirmation of HPIC results for Gd. Collection protocols for the heart-cutting procedure of chromatograms were applied. SPE procedures were also developed not only to extract traces of free gadolinium ions from samples, but also to remove the high level of interfering anions of the complex matrices. The limit of detection, the recoverability and the linearity of the method were also presented.

  8. High Performance Circularly Polarized Microstrip Antenna

    NASA Technical Reports Server (NTRS)

    Bondyopadhyay, Probir K. (Inventor)

    1997-01-01

    A microstrip antenna for radiating circularly polarized electromagnetic waves comprising a cluster array of at least four microstrip radiator elements, each of which is provided with dual orthogonal coplanar feeds in phase quadrature relation achieved by connection to an asymmetric T-junction power divider impedance notched at resonance. The dual fed circularly polarized reference element is positioned with its axis at a 45 deg angle with respect to the unit cell axis. The other three dual fed elements in the unit cell are positioned and fed with a coplanar feed structure with sequential rotation and phasing to enhance the axial ratio and impedance matching performance over a wide bandwidth. The centers of the radiator elements are disposed at the corners of a square with each side of a length d in the range of 0.7 to 0.9 times the free space wavelength of the antenna radiation and the radiator elements reside in a square unit cell area of sides equal to 2d and thereby permit the array to be used as a phased array antenna for electronic scanning and is realizable in a high temperature superconducting thin film material for high efficiency.

  9. Evaluating performance of high efficiency mist eliminators

    SciTech Connect

    Waggoner, Charles A.; Parsons, Michael S.; Giffin, Paxton K.

    2013-07-01

    Processing liquid wastes frequently generates off gas streams with high humidity and liquid aerosols. Droplet laden air streams can be produced from tank mixing or sparging and processes such as reforming or evaporative volume reduction. Unfortunately these wet air streams represent a genuine threat to HEPA filters. High efficiency mist eliminators (HEME) are one option for removal of liquid aerosols with high dissolved or suspended solids content. HEMEs have been used extensively in industrial applications, however they have not seen widespread use in the nuclear industry. Filtering efficiency data along with loading curves are not readily available for these units and data that exist are not easily translated to operational parameters in liquid waste treatment plants. A specialized test stand has been developed to evaluate the performance of HEME elements under use conditions of a US DOE facility. HEME elements were tested at three volumetric flow rates using aerosols produced from an iron-rich waste surrogate. The challenge aerosol included submicron particles produced from Laskin nozzles and super micron particles produced from a hollow cone spray nozzle. Test conditions included ambient temperature and relative humidities greater than 95%. Data collected during testing HEME elements from three different manufacturers included volumetric flow rate, differential temperature across the filter housing, downstream relative humidity, and differential pressure (dP) across the filter element. Filter challenge was discontinued at three intermediate dPs and the filter to allow determining filter efficiency using dioctyl phthalate and then with dry surrogate aerosols. Filtering efficiencies of the clean HEME, the clean HEME loaded with water, and the HEME at maximum dP were also collected using the two test aerosols. Results of the testing included differential pressure vs. time loading curves for the nine elements tested along with the mass of moisture and solid

  10. The curing of high-performance concrete

    NASA Astrophysics Data System (ADS)

    Meeks, Kenneth Wayne

    This dissertation describes the latest information, technology, and research on the curing of high performance concrete (HPC). Expanded somewhat beyond the scope of HPC, it examines the current body of knowledge on the effects of various curing regimes on concrete. The significance and importance of curing are discussed as well as the various definitions of HPC. The current curing requirements, standards, and criteria as proposed by ACI, as well as those of other countries, are reviewed and discussed. The current prescriptive curing requirements may not be applicable to high performance concrete. The research program reported in this dissertation looked at one approach to development of curing criteria for this relatively new class of concrete. The program applies some of the basic concepts of the methodology developed by the German researcher, H. K. Hilsdorf, to the curing of HPC with the objective to determine minimum curing durations for adequate strength development. The approach is to determine what fraction of the standard-cured 28-day strength has to be attained at the end of the curing period to assure that the design strength is attained in the interior of the member. An innovative direct tension test was developed to measure the strength at specific depths from the drying surface of small mortar cylinders (50 x 127 mm (2 x 5 in.)). Two mortar mixtures were investigated, w/c = 0.30 and w/c = 0.45, and three different moist curing regimes, 1-day, 3-day, and 7-day. Specimens were stored in two environmental chambers at 25sp°C, 50% RH; and 25sp°C, 70% RH, until testing at the age of 28 days. Direct tensile tests were conducted using steel disks epoxied to the ends of the specimens. Also, the penetration of the drying front was calculated from the drying data using porosity and degree of hydration relationships. The major observation from these tests was that adequate strength is attained in both mortar mixtures with only one day of moist curing. The drying

  11. High performance vapour-cell frequency standards

    NASA Astrophysics Data System (ADS)

    Gharavipour, M.; Affolderbach, C.; Kang, S.; Bandi, T.; Gruet, F.; Pellaton, M.; Mileti, G.

    2016-06-01

    We report our investigations on a compact high-performance rubidium (Rb) vapour-cell clock based on microwave-optical double-resonance (DR). These studies are done in both DR continuous-wave (CW) and Ramsey schemes using the same Physics Package (PP), with the same Rb vapour cell and a magnetron-type cavity with only 45 cm3 external volume. In the CW-DR scheme, we demonstrate a DR signal with a contrast of 26% and a linewidth of 334 Hz; in Ramsey-DR mode Ramsey signals with higher contrast up to 35% and a linewidth of 160 Hz have been demonstrated. Short-term stabilities of 1.4×10-13 τ-1/2 and 2.4×10-13 τ-1/2 are measured for CW-DR and Ramsey-DR schemes, respectively. In the Ramsey-DR operation, thanks to the separation of light and microwave interactions in time, the light-shift effect has been suppressed which allows improving the long-term clock stability as compared to CW-DR operation. Implementations in miniature atomic clocks are considered.

  12. High performance techniques for space mission scheduling

    NASA Technical Reports Server (NTRS)

    Smith, Stephen F.

    1994-01-01

    In this paper, we summarize current research at Carnegie Mellon University aimed at development of high performance techniques and tools for space mission scheduling. Similar to prior research in opportunistic scheduling, our approach assumes the use of dynamic analysis of problem constraints as a basis for heuristic focusing of problem solving search. This methodology, however, is grounded in representational assumptions more akin to those adopted in recent temporal planning research, and in a problem solving framework which similarly emphasizes constraint posting in an explicitly maintained solution constraint network. These more general representational assumptions are necessitated by the predominance of state-dependent constraints in space mission planning domains, and the consequent need to integrate resource allocation and plan synthesis processes. First, we review the space mission problems we have considered to date and indicate the results obtained in these application domains. Next, we summarize recent work in constraint posting scheduling procedures, which offer the promise of better future solutions to this class of problems.

  13. High performance graphene oxide based rubber composites.

    PubMed

    Mao, Yingyan; Wen, Shipeng; Chen, Yulong; Zhang, Fazhong; Panine, Pierre; Chan, Tung W; Zhang, Liqun; Liang, Yongri; Liu, Li

    2013-01-01

    In this paper, graphene oxide/styrene-butadiene rubber (GO/SBR) composites with complete exfoliation of GO sheets were prepared by aqueous-phase mixing of GO colloid with SBR latex and a small loading of butadiene-styrene-vinyl-pyridine rubber (VPR) latex, followed by their co-coagulation. During co-coagulation, VPR not only plays a key role in the prevention of aggregation of GO sheets but also acts as an interface-bridge between GO and SBR. The results demonstrated that the mechanical properties of the GO/SBR composite with 2.0 vol.% GO is comparable with those of the SBR composite reinforced with 13.1 vol.% of carbon black (CB), with a low mass density and a good gas barrier ability to boot. The present work also showed that GO-silica/SBR composite exhibited outstanding wear resistance and low-rolling resistance which make GO-silica/SBR very competitive for the green tire application, opening up enormous opportunities to prepare high performance rubber composites for future engineering applications.

  14. High Performance Graphene Oxide Based Rubber Composites

    NASA Astrophysics Data System (ADS)

    Mao, Yingyan; Wen, Shipeng; Chen, Yulong; Zhang, Fazhong; Panine, Pierre; Chan, Tung W.; Zhang, Liqun; Liang, Yongri; Liu, Li

    2013-08-01

    In this paper, graphene oxide/styrene-butadiene rubber (GO/SBR) composites with complete exfoliation of GO sheets were prepared by aqueous-phase mixing of GO colloid with SBR latex and a small loading of butadiene-styrene-vinyl-pyridine rubber (VPR) latex, followed by their co-coagulation. During co-coagulation, VPR not only plays a key role in the prevention of aggregation of GO sheets but also acts as an interface-bridge between GO and SBR. The results demonstrated that the mechanical properties of the GO/SBR composite with 2.0 vol.% GO is comparable with those of the SBR composite reinforced with 13.1 vol.% of carbon black (CB), with a low mass density and a good gas barrier ability to boot. The present work also showed that GO-silica/SBR composite exhibited outstanding wear resistance and low-rolling resistance which make GO-silica/SBR very competitive for the green tire application, opening up enormous opportunities to prepare high performance rubber composites for future engineering applications.

  15. High Performance Graphene Oxide Based Rubber Composites

    PubMed Central

    Mao, Yingyan; Wen, Shipeng; Chen, Yulong; Zhang, Fazhong; Panine, Pierre; Chan, Tung W.; Zhang, Liqun; Liang, Yongri; Liu, Li

    2013-01-01

    In this paper, graphene oxide/styrene-butadiene rubber (GO/SBR) composites with complete exfoliation of GO sheets were prepared by aqueous-phase mixing of GO colloid with SBR latex and a small loading of butadiene-styrene-vinyl-pyridine rubber (VPR) latex, followed by their co-coagulation. During co-coagulation, VPR not only plays a key role in the prevention of aggregation of GO sheets but also acts as an interface-bridge between GO and SBR. The results demonstrated that the mechanical properties of the GO/SBR composite with 2.0 vol.% GO is comparable with those of the SBR composite reinforced with 13.1 vol.% of carbon black (CB), with a low mass density and a good gas barrier ability to boot. The present work also showed that GO-silica/SBR composite exhibited outstanding wear resistance and low-rolling resistance which make GO-silica/SBR very competitive for the green tire application, opening up enormous opportunities to prepare high performance rubber composites for future engineering applications. PMID:23974435

  16. High performance hand-held gas chromatograph

    SciTech Connect

    Yu, C.M.

    1998-04-28

    The Microtechnology Center of Lawrence Livermore National Laboratory has developed a high performance hand-held, real time detection gas chromatograph (HHGC) by Micro-Electro-Mechanical-System (MEMS) technology. The total weight of this hand-held gas chromatograph is about five lbs., with a physical size of 8{close_quotes} x 5{close_quotes} x 3{close_quotes} including carrier gas and battery. It consumes about 12 watts of electrical power with a response time on the order of one to two minutes. This HHGC has an average effective theoretical plate of about 40k. Presently, its sensitivity is limited by its thermal sensitive detector at PPM. Like a conventional G.C., this HHGC consists mainly of three major components: (1) the sample injector, (2) the column, and (3) the detector with related electronics. The present HHGC injector is a modified version of the conventional injector. Its separation column is fabricated completely on silicon wafers by means of MEMS technology. This separation column has a circular cross section with a diameter of 100 pm. The detector developed for this hand-held GC is a thermal conductivity detector fabricated on a silicon nitride window by MEMS technology. A normal Wheatstone bridge is used. The signal is fed into a PC and displayed through LabView software.

  17. Flow simulation and high performance computing

    NASA Astrophysics Data System (ADS)

    Tezduyar, T.; Aliabadi, S.; Behr, M.; Johnson, A.; Kalro, V.; Litke, M.

    1996-10-01

    Flow simulation is a computational tool for exploring science and technology involving flow applications. It can provide cost-effective alternatives or complements to laboratory experiments, field tests and prototyping. Flow simulation relies heavily on high performance computing (HPC). We view HPC as having two major components. One is advanced algorithms capable of accurately simulating complex, real-world problems. The other is advanced computer hardware and networking with sufficient power, memory and bandwidth to execute those simulations. While HPC enables flow simulation, flow simulation motivates development of novel HPC techniques. This paper focuses on demonstrating that flow simulation has come a long way and is being applied to many complex, real-world problems in different fields of engineering and applied sciences, particularly in aerospace engineering and applied fluid mechanics. Flow simulation has come a long way because HPC has come a long way. This paper also provides a brief review of some of the recently-developed HPC methods and tools that has played a major role in bringing flow simulation where it is today. A number of 3D flow simulations are presented in this paper as examples of the level of computational capability reached with recent HPC methods and hardware. These examples are, flow around a fighter aircraft, flow around two trains passing in a tunnel, large ram-air parachutes, flow over hydraulic structures, contaminant dispersion in a model subway station, airflow past an automobile, multiple spheres falling in a liquid-filled tube, and dynamics of a paratrooper jumping from a cargo aircraft.

  18. High-performance commercial building systems

    SciTech Connect

    Selkowitz, Stephen

    2003-10-01

    This report summarizes key technical accomplishments resulting from the three year PIER-funded R&D program, ''High Performance Commercial Building Systems'' (HPCBS). The program targets the commercial building sector in California, an end-use sector that accounts for about one-third of all California electricity consumption and an even larger fraction of peak demand, at a cost of over $10B/year. Commercial buildings also have a major impact on occupant health, comfort and productivity. Building design and operations practices that influence energy use are deeply engrained in a fragmented, risk-averse industry that is slow to change. Although California's aggressive standards efforts have resulted in new buildings designed to use less energy than those constructed 20 years ago, the actual savings realized are still well below technical and economic potentials. The broad goal of this program is to develop and deploy a set of energy-saving technologies, strategies, and techniques, and improve processes for designing, commissioning, and operating commercial buildings, while improving health, comfort, and performance of occupants, all in a manner consistent with sound economic investment practices. Results are to be broadly applicable to the commercial sector for different building sizes and types, e.g. offices and schools, for different classes of ownership, both public and private, and for owner-occupied as well as speculative buildings. The program aims to facilitate significant electricity use savings in the California commercial sector by 2015, while assuring that these savings are affordable and promote high quality indoor environments. The five linked technical program elements contain 14 projects with 41 distinct R&D tasks. Collectively they form a comprehensive Research, Development, and Demonstration (RD&D) program with the potential to capture large savings in the commercial building sector, providing significant economic benefits to building owners and

  19. High Performance Input/Output Systems for High Performance Computing and Four-Dimensional Data Assimilation

    NASA Technical Reports Server (NTRS)

    Fox, Geoffrey C.; Ou, Chao-Wei

    1997-01-01

    The approach of this task was to apply leading parallel computing research to a number of existing techniques for assimilation, and extract parameters indicating where and how input/output limits computational performance. The following was used for detailed knowledge of the application problems: 1. Developing a parallel input/output system specifically for this application 2. Extracting the important input/output characteristics of data assimilation problems; and 3. Building these characteristics s parameters into our runtime library (Fortran D/High Performance Fortran) for parallel input/output support.

  20. High Performance Liquid Chromatography/Video Fluorometry. Part I. Instrumentation.

    DTIC Science & Technology

    1981-09-30

    High Performance Liquid Chromatography /Video...PERIOD COVERED High Performance Liquid Chromatography /Video .. / Fluorometry. Part I. Instrumentation. . Interim/ echnicaliepart,. 6. PERFORMING ORG...34Entered SECURITY CLASSIFICATION OF THIS OlAGE (When Data Entered) II1| III I I I I E I II ... .. High Performance Liquid Chromatography

  1. MCFC PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    Unknown

    2000-01-01

    This contract is supported by DOE and DOD/DARPA funds. The objective of the DOE program is to advance the direct carbonate fuel cell technology to a level suitable for commercial entry. The specific objectives of the DOD's initiative on 2 MW Fuel Cell Fixed Base Power Plant are: (A) to provide a detailed engineering design, development and cost estimate of the 2 MW fuel cell fixed base dual fuel power plant for DOD applications. Installation and operational support systems will also be developed. (B) To construct a full-size MW-class dual fuel power plant simulator.

  2. MCFC PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    Unknown

    2000-04-30

    The objective of the DOE program is to advance the direct carbonate fuel cell technology to a level suitable for commercial entry. The specific objectives of the DOD's initiative on 2 MW Fuel Cell Fixed Base Power Plant are: (1) To provide a detailed engineering design, development and cost estimate of the 2 MW fuel cell fixed base dual fuel power plant for DOD applications. Installation and operational support systems will also be developed. (2) To construct a full-size MW-class dual fuel power plant simulator. These objectives are planned to be achieved in the program coordinated with the Department of Energy, which has been funding a multiyear natural gas fueled direct fuel cell power plant program (DE-FC21-95MC31184) for civilian applications. Because many DARPA and DOE objectives are similar, the coordinated program activities are considered the most cost-effective for accomplishment of the program objectives. The DARPA/DOE joint program was launched in 1994. The DOE part of the program is expected to continue to Year 2000. The final output of this DOE program is to construct and operate a 2 MW power plant on an East Coast site. The site will be accessible to DOD energy/environmental systems base planners and logistics personnel as well as mission and policy planners to refine deployment configurations of this new power generation system for fixed base applications.

  3. MCFC product design improvement

    SciTech Connect

    Unknown

    1999-05-01

    This contract is supported by DOE and DOD/DARPA funds. The objective of the DOE program is to advance the direct carbonate fuel cell technology to a level suitable for commercial entry. The specific objectives of the DOE's initiative on 2 MW Fuel Cell Fixed Base Power Plant are: (A) To provide a detailed engineering design, development and cost estimate of the 2 MW fuel cell fixed base dual fuel power plant for DOD applications. Installation and operational support systems will also be developed; and (B) To construct a full-size MW-class dual fuel power plant simulator. These objectives are planned to be achieved in the program coordinated with the Department of Energy, which has been funding a multiyear natural gas fueled direct fuel cell power plant program for civilian applications. Because many DARPA and DOE objectives are similar, the coordinated program activities are considered the most cost-effective for accomplishment of the program objectives. The DARPA/DOE joint program was launched in 1994. The DOE part of the program is expected to continue to the year 2000. The final output of this DOE program is to construct and operate a 2 MW power plant on an East Coast site. The site will be accessible to DOD energy/environmental systems base planners and logistics personnel as well as mission and policy planners to refine deployment configurations of this new power generation system for fixed base applications. A dual fuel fixed base design for military fuels operation, as well as support system logistics will be the key deliverables for the DARPA part of the program.

  4. High performance MEMS micro-gyroscope

    NASA Technical Reports Server (NTRS)

    Bae, S. Y.; Hayworth, K. J.; Yee, K. Y.; Shcheglov, K.; Challoner, A. D.; Wiberg, D. V.

    2002-01-01

    This paper reports on JPL's on-going research into MEMS gyroscopes. This paper will describe the gyroscope's fabrication-methods, a new 8-electrode layout developed to improve performance, and performance statistics of a batch of six gyroscopes recently rate tested.

  5. Spectrally high performing quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Toor, Fatima

    Quantum cascade (QC) lasers are versatile semiconductor light sources that can be engineered to emit light of almost any wavelength in the mid- to far-infrared (IR) and terahertz region from 3 to 300 mum [1-5]. Furthermore QC laser technology in the mid-IR range has great potential for applications in environmental, medical and industrial trace gas sensing [6-10] since several chemical vapors have strong rovibrational frequencies in this range and are uniquely identifiable by their absorption spectra through optical probing of absorption and transmission. Therefore, having a wide range of mid-IR wavelengths in a single QC laser source would greatly increase the specificity of QC laser-based spectroscopic systems, and also make them more compact and field deployable. This thesis presents work on several different approaches to multi-wavelength QC laser sources that take advantage of band-structure engineering and the uni-polar nature of QC lasers. Also, since for chemical sensing, lasers with narrow linewidth are needed, work is presented on a single mode distributed feedback (DFB) QC laser. First, a compact four-wavelength QC laser source, which is based on a 2-by-2 module design, with two waveguides having QC laser stacks for two different emission wavelengths each, one with 7.0 mum/11.2 mum, and the other with 8.7 mum/12.0 mum is presented. This is the first design of a four-wavelength QC laser source with widely different emission wavelengths that uses minimal optics and electronics. Second, since there are still several unknown factors that affect QC laser performance, results on a first ever study conducted to determine the effects of waveguide side-wall roughness on QC laser performance using the two-wavelength waveguides is presented. The results are consistent with Rayleigh scattering effects in the waveguides, with roughness effecting shorter wavelengths more than longer wavelengths. Third, a versatile time-multiplexed multi-wavelength QC laser system that

  6. Bedford Farmhouse High Performance Retrofit Prototype

    SciTech Connect

    2010-04-26

    In this case study, Building Science Corporation partnered with Habitat for Humanity of Greater Lowell on a retrofit of a mid-19th century farmhouse into affordable housing meeting Building America performance standards.

  7. High Performance Electrolyzers for Hybrid Thermochemical Cycles

    SciTech Connect

    Dr. John W. Weidner

    2009-05-10

    Extensive electrolyzer testing was performed at the University of South Carolina (USC). Emphasis was given to understanding water transport under various operating (i.e., temperature, membrane pressure differential and current density) and design (i.e., membrane thickness) conditions when it became apparent that water transport plays a deciding role in cell voltage. A mathematical model was developed to further understand the mechanisms of water and SO2 transport, and to predict the effect of operating and design parameters on electrolyzer performance.

  8. Secrets of high-performance image display

    NASA Astrophysics Data System (ADS)

    Desormeaux, David A.

    1996-04-01

    Medical imaging companies have traditionally supplied the industry with image visualization solutions based on their own custom hardware designs. Today, more and more systems are being deployed using only off-the-shelf workstations. Two major factors are driving this change. First, workstations are delivering the functionality and performance required to replace custom hardware for an ever increasing subset of visualization techniques, while continuing to come down in cost. Second, cost pressures are forcing medical imaging companies to OEM the hardware platform and focus on what they do best -- delivering solutions to health care providers. This industry shift is challenging the workstation vendors to deliver the maximum inherent performance in their computer systems to medical imaging applications without locking the application into a specific vendor's hardware. Since extracting the maximum performance from a workstation is not always intuitively obvious and often requires vendor-specific tricks, the best way to deliver performance to an application is through an application programmer's interface (API). The Hewlett-Packard Image Visualization Library (HP-IVL) is such an API. It transparently delivers the maximum possible imaging performance on Hewlett-Packard workstations, while allowing significant portability between platforms. This paper describes the performance tricks and trade-offs made in the software implementation of HP's Image Visualization Library and how the HP Image Visualization Accelerator (HP-IVX) fits into the overall architecture.

  9. Benchmarking: More Aspects of High Performance Computing

    SciTech Connect

    Ravindrudu, Rahul

    2004-01-01

    The original HPL algorithm makes the assumption that all data can be fit entirely in the main memory. This assumption will obviously give a good performance due to the absence of disk I/O. However, not all applications can fit their entire data in memory. These applications which require a fair amount of I/O to move data to and from main memory and secondary storage, are more indicative of usage of an Massively Parallel Processor (MPP) System. Given this scenario a well designed I/O architecture will play a significant part in the performance of the MPP System on regular jobs. And, this is not represented in the current Benchmark. The modified HPL algorithm is hoped to be a step in filling this void. The most important factor in the performance of out-of-core algorithms is the actual I/O operations performed and their efficiency in transferring data to/from main memory and disk, Various methods were introduced in the report for performing I/O operations. The I/O method to use depends on the design of the out-of-core algorithm. Conversely, the performance of the out-of-core algorithm is affected by the choice of I/O operations. This implies, good performance is achieved when I/O efficiency is closely tied with the out-of-core algorithms. The out-of-core algorithms must be designed from the start. It is easily observed in the timings for various plots, that I/O plays a significant part in the overall execution time. This leads to an important conclusion, retro-fitting an existing code may not be the best choice. The right-looking algorithm selected for the LU factorization is a recursive algorithm and performs well when the entire dataset is in memory. At each stage of the loop the entire trailing submatrix is read into memory panel by panel. This gives a polynomial number of I/O reads and writes. If the left-looking algorithm was selected for the main loop, the number of I/O operations involved will be linear on the number of columns. This is due to the data access

  10. High Performance Home Building Guide for Habitat for Humanity Affiliates

    SciTech Connect

    Lindsey Marburger

    2010-10-01

    This guide covers basic principles of high performance Habitat construction, steps to achieving high performance Habitat construction, resources to help improve building practices, materials, etc., and affiliate profiles and recommendations.

  11. High performance SMC matrix for structural applications

    NASA Astrophysics Data System (ADS)

    Salard, T.; Lortie, F.; Gérard, J. F.; Peyre, C.

    2016-07-01

    Mechanical properties of a common SMC (Sheet Molding Compound) matrix constituted of a vinylester resin and a Low-Profile Additive (LPA) were compared to those of vinylester modified with core-shell rubber (CSR) particles. Valuable properties are brought by CSR, especially high impact strength, high fracture toughness with little loss in stiffness, in spite of the presence of CSR agglomerates in blends.

  12. Nanostructured high-performance dielectric block copolymers.

    PubMed

    Liu, Wenmei; Liao, Xiaojuan; Li, Yawei; Zhao, Qiuhua; Xie, Meiran; Sun, Ruyi

    2015-10-25

    A new type of insulating-conductive block copolymer was synthesized by metathesis polymerization. The copolymer can self-assemble into unique nanostructures of micelles or hollow spheres. It exhibits a high dielectric constant, low dielectric loss, and high stored/released energy density due to the strong dipolar and nano-interfacial polarization contributions.

  13. New materials drive high-performance aircraft

    NASA Technical Reports Server (NTRS)

    Ruhmann, Douglas C.; Bates, William F., Jr.; Dexter, H. B.; June, Reid B.

    1992-01-01

    This report shows how advanced composite materials and new processing methods are enabling lighter, lower cost aircraft structures. High-temperature polymers research will focus on systems capable of 50,000 to 100,000 hours of operation in the 212-400 F temperature range. Prospective materials being evaluated include high-temperature epoxies, toughened bismaleimides, cyanates, thermoplastics, polyimides and other polymers.

  14. Green Schools as High Performance Learning Facilities

    ERIC Educational Resources Information Center

    Gordon, Douglas E.

    2010-01-01

    In practice, a green school is the physical result of a consensus process of planning, design, and construction that takes into account a building's performance over its entire 50- to 60-year life cycle. The main focus of the process is to reinforce optimal learning, a goal very much in keeping with the parallel goals of resource efficiency and…

  15. Engaging Low Performing High School French Students

    ERIC Educational Resources Information Center

    Leopold, Amy

    2011-01-01

    Acquiring a second language in the United States is not something that many American citizens accomplish. Research has attributed an array of factors to student motivation, engagement, and success with learning a foreign language. However, low performing and struggling students that take foreign language and the strategies used to motivate them…

  16. High performance S-type cathode

    SciTech Connect

    Chu, M.Y.; Visco, S.J.; De Jonghe, L.C.

    1997-12-01

    PolyPlus Battery Company (PPBC) is developing an advanced lithium polymer rechargeable battery based on proprietary positive electrode chemistry. In one formulation, this electrode contains elemental sulfur, either free or in association with secondary materials that promote its utilization. Batteries based on this cathode chemistry offer high steady-state (>250 W/kg) and high peak power densities (3,000 W/kg), in a low cost and environmentally benign format. High energy density, in excess of 500 Wh/kg (600 Wh/l) can also be achieved. The high power and energy densities, along with the low toxicity and low cost of materials used in the PolyPlus solid-state cells make this battery exceptionally attractive for both hybrid and electric vehicles, and for consumer electronic applications.

  17. High Performance Heat Storage and Dissipation Technology

    DTIC Science & Technology

    2005-11-11

    Heat storage, metal hydride , phase change material, solid state laser, cooling, heat pipe, directed energy weapon ABSTRACT High power solid state...high power solid state laser systems. The greater volumetric heat storage capacity of metal hydrides than the conventional PCMs can be translated...into very compact systems with shorter heat transfer paths and therefore less thermal resistance. Other exclusive properties of the metal hydride

  18. High Performance Green LEDs by Homoepitaxial

    SciTech Connect

    Wetzel, Christian; Schubert, E Fred

    2009-11-22

    This work's objective was the development of processes to double or triple the light output power from green and deep green (525 - 555 nm) AlGaInN light emitting diode (LED) dies within 3 years in reference to the Lumileds Luxeon II. The project paid particular effort to all aspects of the internal generation efficiency of light. LEDs in this spectral region show the highest potential for significant performance boosts and enable the realization of phosphor-free white LEDs comprised by red-green-blue LED modules. Such modules will perform at and outperform the efficacy target projections for white-light LED systems in the Department of Energy's accelerated roadmap of the SSL initiative.

  19. High-performance iodine fiber frequency standard.

    PubMed

    Lurie, Anna; Baynes, Fred N; Anstie, James D; Light, Philip S; Benabid, Fetah; Stace, Thomas M; Luiten, Andre N

    2011-12-15

    We have constructed a compact and robust optical frequency standard based around iodine vapor loaded into the core of a hollow-core photonic crystal fiber (HC-PCF). A 532 nm laser was frequency locked to one hyperfine component of the R(56) 32-0 (127)I(2) transition using modulation transfer spectroscopy. The stabilized laser demonstrated a frequency stability of 2.3×10(-12) at 1 s, almost an order of magnitude better than previously reported for a laser stabilized to a gas-filled HC-PCF. This limit is set by the shot noise in the detection system. We present a discussion of the current limitations to the performance and a route to improve the performance by more than an order of magnitude.

  20. High Performance Auxiliary Power Unit Technology Demonstrator.

    DTIC Science & Technology

    1980-12-01

    engine performance with an accompanying re- duction in engine complexity and cost . Significant growth potential has also been designed into the...reducing the number of fuel injectors normally required to one half. This reduction in the number of injectors provides a cost savings feature. 11 ho...of uniform thickness for minimum cost , without being over stressed at any point along the cone. At the rear header, where variable thickness is

  1. High performance compound semiconductor SPAD arrays

    NASA Astrophysics Data System (ADS)

    Harmon, Eric S.; Naydenkov, Mikhail; Bowling, Jared

    2016-05-01

    Aggregated compound semiconductor single photon avalanche diode (SPAD) arrays are emerging as a viable alternative to the silicon photomultiplier (SiPM). Compound semiconductors have the potential to surpass SiPM performance, potentially achieving orders of magnitude lower dark count rates and improved radiation hardness. New planar processing techniques have been developed to enable compound semiconductor SPAD devices to be produced with pixel pitches of 11 - 25 microns, with thousands of SPADs per array.

  2. PMR polyimides with improved high temperature performance

    NASA Technical Reports Server (NTRS)

    Vannucci, R. D.; Alston, W. B.

    1975-01-01

    Studies were performed to investigate the effect of substituting a hexafluoro isopropyl idene connecting group for a carbonyl group of a PMR polyimide monomeric reactant on the thermo-mechanical properties processability of graphite fiber reinforced PMR polyimide composites. Composites were fabricated utilizing PMR methodology. Monomeric reactant solutions of various stoichiometric ratios were used to impregnate Hercules HTS graphite fiber. The processing characteristics and elevated temperature (600 F) mechanical properties of the composites are described.

  3. High performance flat plate solar collector

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Reynolds, R.

    1976-01-01

    The potential use of porous construction is presented to achieve efficient heat removal from a power producing solid and is applied to solar air heaters. Analytical solutions are given for the temperature distribution within a gas-cooled porous flat plate having its surface exposed to the sun's energy. The extracted thermal energy is calculated for two different types of plate transparency. Results show the great improvement in performance obtained with porous flat plate collectors as compared with analogous nonporous types.

  4. High Rate Performing Li-ion Battery

    DTIC Science & Technology

    2015-02-09

    developing novel 18650 cells with new electrode chemistry, LVP cathode material has been scaled up successfully up to 50 g in one pot. The electrochemical ...systematically from 25 to 100g using one pot synthesis approach and its electrochemical performance was evaluated in each batch. Commercial type lithium-ion...systematic morphology examination, electrochemical study, ex-situ XRD and electron spin resonance (ESR) experiments to address above questions. We

  5. High performance zinc anode for battery applications

    NASA Technical Reports Server (NTRS)

    Casey, John E., Jr. (Inventor)

    1998-01-01

    An improved zinc anode for use in a high density rechargeable alkaline battery is disclosed. A process for making the zinc electrode comprises electrolytic loading of the zinc active material from a slightly acidic zinc nitrate solution into a substrate of nickel, copper or silver. The substrate comprises a sintered plaque having very fine pores, a high surface area, and 80-85 percent total initial porosity. The residual porosity after zinc loading is approximately 25-30%. The electrode of the present invention exhibits reduced zinc mobility, shape change and distortion, and demonstrates reduced dendrite buildup cycling of the battery. The disclosed battery is useful for applications requiring high energy density and multiple charge capability.

  6. Radiation effects on high performance polymers

    NASA Technical Reports Server (NTRS)

    Orwoll, R. A.

    1986-01-01

    Polymer matrix materials are candidates for use in large space antennas and space platforms that may be deployed in geosynchronous orbit 22,500 miles above the Earth. A principal concern is the long term effects of an environment that is hostile to organic polymers, including high energy electromagnetic radiation, bombardment by charged particles, and large abrupt changes in temperature. Two polyarylene ethers which might be utilized as models for polymers in space applications were subjected to dosages of 70 keV electrons up to 3.4 x 10 to the 10th power rad. The irradiated films were then examined to determine the effects of the high-energy electrons.

  7. High performance MPEG-audio decoder IC

    NASA Technical Reports Server (NTRS)

    Thorn, M.; Benbassat, G.; Cyr, K.; Li, S.; Gill, M.; Kam, D.; Walker, K.; Look, P.; Eldridge, C.; Ng, P.

    1993-01-01

    The emerging digital audio and video compression technology brings both an opportunity and a new challenge to IC design. The pervasive application of compression technology to consumer electronics will require high volume, low cost IC's and fast time to market of the prototypes and production units. At the same time, the algorithms used in the compression technology result in complex VLSI IC's. The conflicting challenges of algorithm complexity, low cost, and fast time to market have an impact on device architecture and design methodology. The work presented in this paper is about the design of a dedicated, high precision, Motion Picture Expert Group (MPEG) audio decoder.

  8. Study of high performance alloy electroforming

    NASA Technical Reports Server (NTRS)

    Malone, G. A.

    1985-01-01

    The nickel-manganese experimental electrolyte was hydrogen peroxide treated and carbon purified for removal of residual sodium saccharin and related organic decomposition products from the plating of previous test panels. The saccharin additive was used to reduce stress where high concentrations of manganese and high pulse peak current densities were used. A large quantity of nickel-manganese alloy plates containing 0.35 to 0.40 percent by weight manganese was electroformed for testing to supply data for a mechanical property data table. The aluminum billet required for the machining of the subscale SSME main combustion chamber was acquired.

  9. High performance polymer tandem solar cell

    PubMed Central

    da Silva, Wilson Jose; Schneider, Fabio Kurt; Mohd Yusoff, Abd. Rashid bin; Jang, Jin

    2015-01-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is generated and extracted under dark conditions. This indicates that careful interface engineering of the charge-carrier transport layer is a useful approach to further improve the performance of polymer tandem solar cells. PMID:26669577

  10. A programmable MTD system with high performance

    NASA Astrophysics Data System (ADS)

    Peng, Ying-Ning; Ma, Zang-E.; Ding, Xiu-Dong; Wang, Xiu-Tan; Fu, Jeng-Yun

    A digital programmable MTD system has been developed recently. In this system slow and fast moving targets are detected by a 64-order complex FIR filter and 64-point FFT equivalent filter bank, respectively. The method which obtains land clutter CFAR threshold for every Doppler channel with very good performance is proposed. When power spectral density of land clutter has a certain cubic shape, an average signal to clutter ratio improvement factor of about 48dB could be realized in this system.

  11. Alexandrite-laser performance at high temperature

    SciTech Connect

    Guch, S. Jr.; Jones, C.E.

    1982-12-01

    The performance of a flash-pumped alexandrite laser operating in a long-pulse mode has been characterized at temperatures from 34 to 310 /sup 0/C. Laser gain and efficiency increased monotonically up to 225 /sup 0/C, with a peak pulse energy there more than four times the value at 34 /sup 0/C. The output wavelength also increased monotonically from the 34 /sup 0/C value of 752 nm to a maximum of 790 nm at 310 /sup 0/C.

  12. High performance image processing of SPRINT

    SciTech Connect

    DeGroot, T.

    1994-11-15

    This talk will describe computed tomography (CT) reconstruction using filtered back-projection on SPRINT parallel computers. CT is a computationally intensive task, typically requiring several minutes to reconstruct a 512x512 image. SPRINT and other parallel computers can be applied to CT reconstruction to reduce computation time from minutes to seconds. SPRINT is a family of massively parallel computers developed at LLNL. SPRINT-2.5 is a 128-node multiprocessor whose performance can exceed twice that of a Cray-Y/MP. SPRINT-3 will be 10 times faster. Described will be the parallel algorithms for filtered back-projection and their execution on SPRINT parallel computers.

  13. High-performance commercial building facades

    SciTech Connect

    Lee, Eleanor; Selkowitz, Stephen; Bazjanac, Vladimir; Inkarojrit, Vorapat; Kohler, Christian

    2002-06-01

    This study focuses on advanced building facades that use daylighting, sun control, ventilation systems, and dynamic systems. A quick perusal of the leading architectural magazines, or a discussion in most architectural firms today will eventually lead to mention of some of the innovative new buildings that are being constructed with all-glass facades. Most of these buildings are appearing in Europe, although interestingly U.S. A/E firms often have a leading role in their design. This ''emerging technology'' of heavily glazed fagades is often associated with buildings whose design goals include energy efficiency, sustainability, and a ''green'' image. While there are a number of new books on the subject with impressive photos and drawings, there is little critical examination of the actual performance of such buildings, and a generally poor understanding as to whether they achieve their performance goals, or even what those goals might be. Even if the building ''works'' it is often dangerous to take a design solution from one climate and location and transport it to a new one without a good causal understanding of how the systems work. In addition, there is a wide range of existing and emerging glazing and fenestration technologies in use in these buildings, many of which break new ground with respect to innovative structural use of glass. It is unclear as to how well many of these designs would work as currently formulated in California locations dominated by intense sunlight and seismic events. Finally, the costs of these systems are higher than normal facades, but claims of energy and productivity savings are used to justify some of them. Once again these claims, while plausible, are largely unsupported. There have been major advances in glazing and facade technology over the past 30 years and we expect to see continued innovation and product development. It is critical in this process to be able to understand which performance goals are being met by current

  14. High performance flexible electronics for biomedical devices.

    PubMed

    Salvatore, Giovanni A; Munzenrieder, Niko; Zysset, Christoph; Kinkeldei, Thomas; Petti, Luisa; Troster, Gerhard

    2014-01-01

    Plastic electronics is soft, deformable and lightweight and it is suitable for the realization of devices which can form an intimate interface with the body, be implanted or integrated into textile for wearable and biomedical applications. Here, we present flexible electronics based on amorphous oxide semiconductors (a-IGZO) whose performance can achieve MHz frequency even when bent around hair. We developed an assembly technique to integrate complex electronic functionalities into textile while preserving the softness of the garment. All this and further developments can open up new opportunities in health monitoring, biotechnology and telemedicine.

  15. Aromatic Polyimides with High Performances and Deuteration

    SciTech Connect

    Anselmi, E.; Raby, J.; Balland-Longeau, A.

    2004-03-15

    Inertial Confinement Fusion experiments are conducted in polymer capsule in which nuclear products are located. In order to vary optical properties, we need to develop polyimides with high mechanical properties in which we have to substitute all the hydrogen atoms by deuterium atoms. The best way to obtain deuterated polymer is to deuterate monomers instead of direct deuteration of polymers. In a first part, mechanical properties of aromatic polyimide films based on two dianhydrides (pyromellitic dianhydride PMDA and 3,3',4,4'-biphenyltetracarboxylic dianhydride BPDA) and two diamines (4,4'-oxydianiline ODA and pphenylenediamine PDA) have been described. The optimization of synthesis and fabrication parameters of polyimide films PMDA/ODA and BPDA/PDA having high inherent viscosity, so high molecular weight, have allowed us to obtain high mechanical properties. And in a second part, deuterated monomers have been synthesized via multi-steps organic reactions and/or under pressure conditions. We have investigated the preparation of deuterated poly(amic-acid) solutions in NMP and the preparation of the corresponding polyimides deuterated membranes. Results show that deuterium does not affect the reactivity of monomers to form the poly(amic-acid) solution.

  16. High-performance thresholding with adaptive equalization

    NASA Astrophysics Data System (ADS)

    Lam, Ka Po

    1998-09-01

    The ability to simplify an image whilst retaining such crucial information as shapes and geometric structures is of great importance for real-time image analysis applications. Here the technique of binary thresholding which reduces the image complexity has generally been regarded as one of the most valuable methods, primarily owing to its ease of design and analysis. This paper studies the state of developments in the field, and describes a radically different approach of adaptive thresholding. The latter employs the analytical technique of histogram normalization for facilitating an optimal `contrast level' of the image under consideration. A suitable criterion is also developed to determine the applicability of the adaptive processing procedure. In terms of performance and computational complexity, the proposed algorithm compares favorably to five established image thresholding methods selected for this study. Experimental results have shown that the new algorithm outperforms these methods in terms of a number of important errors measures, including a consistently low visual classification error performance. The simplicity of design of the algorithm also lends itself to efficient parallel implementations.

  17. A high performance totally ordered multicast protocol

    NASA Technical Reports Server (NTRS)

    Montgomery, Todd; Whetten, Brian; Kaplan, Simon

    1995-01-01

    This paper presents the Reliable Multicast Protocol (RMP). RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service such as IP Multicasting. RMP is fully and symmetrically distributed so that no site bears un undue portion of the communication load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered delivery, to K-resilient, majority resilient, and totally resilient atomic delivery. These QoS guarantees are selectable on a per packet basis. RMP provides many communication options, including virtual synchrony, a publisher/subscriber model of message delivery, an implicit naming service, mutually exclusive handlers for messages, and mutually exclusive locks. It has commonly been held that a large performance penalty must be paid in order to implement total ordering -- RMP discounts this. On SparcStation 10's on a 1250 KB/sec Ethernet, RMP provides totally ordered packet delivery to one destination at 842 KB/sec throughput and with 3.1 ms packet latency. The performance stays roughly constant independent of the number of destinations. For two or more destinations on a LAN, RMP provides higher throughput than any protocol that does not use multicast or broadcast.

  18. High Performance, Three-Dimensional Bilateral Filtering

    SciTech Connect

    Bethel, E. Wes

    2008-06-05

    Image smoothing is a fundamental operation in computer vision and image processing. This work has two main thrusts: (1) implementation of a bilateral filter suitable for use in smoothing, or denoising, 3D volumetric data; (2) implementation of the 3D bilateral filter in three different parallelization models, along with parallel performance studies on two modern HPC architectures. Our bilateral filter formulation is based upon the work of Tomasi [11], but extended to 3D for use on volumetric data. Our three parallel implementations use POSIX threads, the Message Passing Interface (MPI), and Unified Parallel C (UPC), a Partitioned Global Address Space (PGAS) language. Our parallel performance studies, which were conducted on a Cray XT4 supercomputer and aquad-socket, quad-core Opteron workstation, show our algorithm to have near-perfect scalability up to 120 processors. Parallel algorithms, such as the one we present here, will have an increasingly important role for use in production visual analysis systems as the underlying computational platforms transition from single- to multi-core architectures in the future.

  19. High Performance Airbrushed Organic Thin Film Transistors

    SciTech Connect

    Chan, C.; Richter, L; Dinardo, B; Jaye, C; Conrad, B; Ro, H; Germack, D; Fischer, D; DeLongchamp, D; Gunlach, D

    2010-01-01

    Spray-deposited poly-3-hexylthiophene (P3HT) transistors were characterized using electrical and structural methods. Thin-film transistors with octyltrichlorosilane treated gate dielectrics and spray-deposited P3HT active layers exhibited a saturation regime mobility as high as 0.1 cm{sup 2} V{sup -1} s{sup -1}, which is comparable to the best mobilities observed in high molecular mass P3HT transistors prepared using other methods. Optical and atomic force microscopy showed the presence of individual droplets with an average diameter of 20 {micro}m and appreciable large-scale film inhomogeneities. Despite these inhomogeneities, near-edge x-ray absorption fine structure spectroscopy of the device-relevant channel interface indicated excellent orientation of the P3HT.

  20. High-Performance Flexible Waveguiding Photovoltaics

    PubMed Central

    Chou, Chun-Hsien; Chuang, Jui-Kang; Chen, Fang-Chung

    2013-01-01

    The use of flat-plane solar concentrators is an effective approach toward collecting sunlight economically and without sun trackers. The optical concentrators are, however, usually made of rigid glass or plastics having limited flexibility, potentially restricting their applicability. In this communication, we describe flexible waveguiding photovoltaics (FWPVs) that exhibit high optical efficiencies and great mechanical flexibility. We constructed these FWPVs by integrating poly-Si solar cells, a soft polydimethylsiloxane (PDMS) waveguide, and a TiO2-doped backside reflector. Optical microstructures that increase the light harvesting ability of the FWPVs can be fabricated readily, through soft lithography, on the top surface of the PDMS waveguide. Our optimized structure displayed an optical efficiency of greater than 42% and a certified power conversion efficiency (PCE) of 5.57%, with a projected PCE as high as approximately 18%. This approach might open new avenues for the harvesting of solar energy at low cost with efficient, mechanically flexible photovoltaics. PMID:23873225

  1. High Thermoelectric Performance in Copper Telluride

    SciTech Connect

    He, Ying; Zhang, Tiansong; Shi, Xun; Wei, Su-Huai; Chen, Lidong

    2015-06-21

    Recently, Cu 2-δ S and Cu 2-δ Se were reported to have an ultralow thermal conductivity and high thermoelectric figure of merit zT. Thus, as a member of the copper chalcogenide group, Cu 2-δ Te is expected to possess superior zTs because Te is less ionic and heavy. However, the zT value is low in the Cu2Te sintered using spark plasma sintering, which is typically used to fabricate high-density bulk samples. In addition, the extra sintering processes may change the samples’ compositions as well as their physical properties, especially for Cu2Te, which has many stable and meta-stable phases as well as weaker ionic bonding between Cu and Te as compared with Cu2S and Cu2Se. In this study, high-density Cu2Te samples were obtained using direct annealing without a sintering process. In the absence of sintering processes, the samples’ compositions could be well controlled, leading to substantially reduced carrier concentrations that are close to the optimal value. The electrical transports were optimized, and the thermal conductivity was considerably reduced. The zT values were significantly improved—to 1.1 at 1000 K—which is nearly 100% improvement. Furthermore, this method saves substantial time and cost during the sample’s growth. The study demonstrates that Cu 2-δ X (X=S, Se and Te) is the only existing system to show high zTs in the series of compounds composed of three sequential primary group elements.

  2. Noise of High Performance Aircraft at Afterburner

    DTIC Science & Technology

    2016-02-10

    any major differences between the dominant noise components of these jets and those of a standard high temperature laboratory supersonic jet. It is... temperature . In the literature, these characteristic spectra are referred to as similarity spectra. In the present project, these two similarity spectra...and a spectrum of temperature fluctuations together with a characteristic size of the blobs. Development of such a stochastic numerical boundary

  3. High-Performance Synthetic Fibers for Composites

    DTIC Science & Technology

    1992-04-01

    required wastewater treatment . In short, this new process can easily produce the current standard high-quality precursor fiber, but it also has the...FMI Composites LTD); Formation of fibergLass\\preform for composite coupling shaft; Undulating ribbon structure of graphene layers for a PAN-based c...ongoing research and development in areas that are of general importance to fiber science and technology (surface properties and treatments , fiber-matrix

  4. High Thermoelectric Performance in Copper Telluride

    DOE PAGES

    He, Ying; Zhang, Tiansong; Shi, Xun; ...

    2015-06-21

    Recently, Cu 2-δ S and Cu 2-δ Se were reported to have an ultralow thermal conductivity and high thermoelectric figure of merit zT. Thus, as a member of the copper chalcogenide group, Cu 2-δ Te is expected to possess superior zTs because Te is less ionic and heavy. However, the zT value is low in the Cu2Te sintered using spark plasma sintering, which is typically used to fabricate high-density bulk samples. In addition, the extra sintering processes may change the samples’ compositions as well as their physical properties, especially for Cu2Te, which has many stable and meta-stable phasesmore » as well as weaker ionic bonding between Cu and Te as compared with Cu2S and Cu2Se. In this study, high-density Cu2Te samples were obtained using direct annealing without a sintering process. In the absence of sintering processes, the samples’ compositions could be well controlled, leading to substantially reduced carrier concentrations that are close to the optimal value. The electrical transports were optimized, and the thermal conductivity was considerably reduced. The zT values were significantly improved—to 1.1 at 1000 K—which is nearly 100% improvement. Furthermore, this method saves substantial time and cost during the sample’s growth. The study demonstrates that Cu 2-δ X (X=S, Se and Te) is the only existing system to show high zTs in the series of compounds composed of three sequential primary group elements.« less

  5. HIGH TEMPERATURE OXIDATION PERFORMANCE OF ALUMINIDE COATINGS

    SciTech Connect

    Pint, B.A.; Zhang, Y.; Haynes, J.A.; Wright, I.G.

    2003-04-22

    In order to determine the potential benefits and limitations of aluminide coatings, coatings made by chemical vapor deposition (CVD) on Fe- and Ni-base alloy substrates are being evaluated in various high-temperature environments. Testing of coatings on representative ferritic (Fe-9Cr-1Mo) and austenitic (type 304L stainless steel) alloys has found that high frequency thermal cycling (1h cycle time) can significantly degrade the coating. Based on comparison with similar specimens with no thermal cycling or a longer cycle time (100h), this degradation was not due to Al loss from the coating but most likely because of the thermal expansion mismatch between the coating and the substrate. Several coated Ni-base alloys were tested in a high pressure (20atm) steam-CO2 environment for the ZEST (zero-emission steam turbine) program. Coated specimens showed less mass loss than the uncoated specimens after 1000h at 900 C and preliminary characterization examined the post-test coating structure and extent of attack.

  6. New monomers for high performance polymers

    NASA Technical Reports Server (NTRS)

    Gratz, Roy F.

    1993-01-01

    This laboratory has been concerned with the development of new polymeric materials with high thermo-oxidative stability for use in the aerospace and electronics industries. Currently, there is special emphasis on developing matrix resins and composites for the high speed civil transport (HSCT) program. This application requires polymers that have service lifetimes of 60,000 hr at 350 F (177 C) and that are readily processible into void-free composites, preferably by melt-flow or powder techniques that avoid the use of high boiling solvents. Recent work has focused on copolymers which have thermally stable imide groups separated by flexible arylene ether linkages, some with trifluoromethyl groups attached to the aromatic rings. The presence of trifluoromethyl groups in monomers and polymers often improves their solubility and processibility. The goal of this research was to synthesize several new monomers containing pendant trifluoromethyl groups and to incorporate these monomers into new imide/arylene ether copolymers. Initially, work was begun on the synthesis of three target compounds. The first two, 3,5-dihydroxybenzo trifluoride and 3-amino 5-hydroxybenzo trifluoride, are intermediates in the synthesis of more complex monomers. The third, 3,5-bis (3-amino-phenoxy) benzotrifluoride, is an interesting diamine that could be incorporated into a polyimide directly.

  7. High-power hydrogen arcjet performance

    NASA Technical Reports Server (NTRS)

    Haag, Thomas W.; Curran, Francis M.

    1991-01-01

    A hydrogen arcjet was operated at power levels ranging from 5 to 30 kW with three different nozzle geometries. Test results using all three nozzle geometries are reported and include variations of specific impulse with flow rate, and thrust with power. Geometric variables investigated included constrictor diameter, length, and diverging exit angle. The nozzle with a constrictor diameter of 1.78 mm and divergence angle of 20 deg was found to give the highest performance. A specific impulse of 1460 s was attained with this nozzle at a thrust efficiency of 29.8 percent. The best efficiency measured was 34.4 percent at a specific impulse of 1045 s. Post test examination of the cathode showed erosion after 28 hours of operation to be small, and limited to the conical tip where steady state arc attachment occurred. Each nozzle was tested to destruction.

  8. High-power hydrogen arcjet performance

    NASA Technical Reports Server (NTRS)

    Haag, Thomas W.; Curran, Francis M.

    1991-01-01

    A hydrogen arcjet was operated at power levels ranging from 5 to 30 kW with three different nozzle geometries. Test results using all three nozzle geometries are reported and include variations of specific impulse with flow rate, and thrust with power. Geometric variables investigated included constrictor diameter, length, and diverging exit angle. The nozzle with a constrictor diameter of 1.78 mm and divergence angle of 20 degrees was found to give the highest performance. A specific impulse of 1460 s was attained with this nozzle at a thrust efficiency of 29.8 percent. The best efficiency measured was 34.4 percent at a specific impulse of 1045 s. Post test examination of the cathode showed erosion after 28 hours of operation to be small, and limited to the conical tip where steady state arc attachment occurred. Each nozzle was tested to destruction.

  9. Traction contact performance evaluation at high speeds

    NASA Technical Reports Server (NTRS)

    Tevaarwerk, J. L.

    1981-01-01

    The results of traction tests performed on two fluids are presented. These tests covered a pressure range of 1.0 to 2.5 GPa, an inlet temperature range of 30 'C to 70 'C, a speed range of 10 to 80 m/sec, aspect ratios of .5 to 5 and spin from 0 to 2.1 percent. The test results are presented in the form of two dimensionless parameters, the initial traction slope and the maximum traction peak. With the use of a suitable rheological fluid model the actual traction curves measured can now be reconstituted from the two fluid parameters. More importantly, the knowledge of these parameters together with the fluid rheological model, allow the prediction of traction under conditions of spin, slip and any combination thereof. Comparison between theoretically predicted traction under these conditions and those measured in actual traction tests shows that this method gives good results.

  10. High pressure compressor component performance report

    NASA Technical Reports Server (NTRS)

    Cline, S. J.; Fesler, W.; Liu, H. S.; Lovell, R. C.; Shaffer, S. J.

    1983-01-01

    A compressor optimization study defined a 10 stage configuration with a 22.6:1 pressure ratio, an adiabatic efficiency goal of 86.1%, and a polytropic efficiency of 90.6%; the corrected airflow is 53.5 kg/s. Subsequent component testing included three full scale tests: a six stage rig test, a 10 stage rig test, and another 10 stage rig test completed in the second quarter of 1982. Information from these tests is used to select the configuration for a core engine test and an integrated core/low spool test. The test results will also provide data base for the flight propulsion system. The results of the test series with both aerodynamic and mechanical performance of each compressor build are presented. The second 10 stage compressor adiabatic efficiency was 0.848 at a cruise operating point versus a test goal of 0.846.

  11. Teacher Practices in a High Performing, Appalachian Rural High School

    ERIC Educational Resources Information Center

    Estep, Steven A.

    2009-01-01

    The purpose of this exploratory case study was to identify, investigate, and describe factors that contributed to the academic success of Phelps High School, a rural, isolated, Appalachian high school in Pike County Kentucky. The academic index of the school in 2000 was 48% and in a six year period the academic index of the school improved to 94%.…

  12. High Performance Calcium Titanate Nanoparticle ER Fluids

    NASA Astrophysics Data System (ADS)

    Wang, Xuezhao; Shen, Rong; Wen, Weijia; Lu, Kunquan

    A type of calcium titanate (CTO) nanoparticles was synthesized by means of wet chemical method [1] without coating on the particles. The CTO/silicone oil ER fluid exhibits excellent electrorheological properties: high shear stress (~50-100 kPa) under dc electric field, a low current density (less than 2μA/cm2 at 5kV/mm), and long term stability against sedimentation. Although there are not special additives in the ER fluids, it is found from the chemical analysis that a trace of alkyl group, hydroxyl group, carbonyl group and some ions is remained in the particles which may dominate the ER response.

  13. Very High Performance Organic Photonic Devices

    DTIC Science & Technology

    2008-01-15

    warta,.w. Stehie, R.& Karl, N, Ultraput. high moability organic pluonocondluctors. Appi Phys. A36. cold weld. Finally, the strike layer between the...Roman, and 0. Inganas. J1. AppI . Phys. C. Silva. Phys. Rev. Lett. 92, 247402 (2004). 86. 487 (1999). 36T Offermans, P. A. van Hal, S. C. J. Meskers. M... AppI . Phys. 97. 103706 093502( (2005). (2005). 38K. L. Mutolo. E. 1. Mayo, B. P. Rand, S. R. Forre%t. and M. E. 27 . Riedel. J. Parisi. V. Dyakonov. L

  14. High-performance planar nanoscale dielectric capacitors

    NASA Astrophysics Data System (ADS)

    Özçelik, V. Ongun; Ciraci, S.

    2015-05-01

    We propose a model for planar nanoscale dielectric capacitors consisting of a single layer, insulating hexagonal boron nitride (BN) stripe placed between two metallic graphene stripes, all forming commensurately a single atomic plane. First-principles density functional calculations on these nanoscale capacitors for different levels of charging and different widths of graphene-BN stripes mark high gravimetric capacitance values, which are comparable to those of supercapacitors made from other carbon-based materials. Present nanocapacitor models allow the fabrication of series, parallel, and mixed combinations which offer potential applications in two-dimensional flexible nanoelectronics, energy storage, and heat-pressure sensing systems.

  15. New design of high performance ionizing bar

    NASA Astrophysics Data System (ADS)

    Wang, Ronggang; Sun, Yurong

    2013-03-01

    This paper introduces a new design of DC-pulse ionizing bar to solve the problem of imbalance offset voltage for the AC ionizing bar, which is easily affected by the environment, as well as indicate the final tests. The new design mainly includes five parts: power supply circuit, main control unit, logic circuit, high frequency transformer unit, and feedback unit. The ionizing bar can automatically adjust the discharge voltage, pulse frequency and pulse width to balance the positive and negative ions. The final test results indicate that the DC ionizing bar owns good effect in electrostatic elimination.

  16. Submarine High Pressure Dehydrator Performance Test

    DTIC Science & Technology

    1988-06-07

    Hatala of September 1985. Prepared for NAVSEA 05N under contract number N00024-33-C-2111. 13. General Dynamics Corporation, High Pressure Air Filtration...Cooling Water Pump Gear Ratio ............... 4:1 Cooling Water Pump Full Load Speed .......... 3500 rpm Water Pump TDH @ 3400 RPM & 15 GPM...Temperature Monitor Thomas A. Edison, Inc. 12-1/2" x 7-1/4" x 9" 25 lbs. Motor Electro Dynamic 2𔄁-1/16" x 2𔃾-1/4" x 2𔃻-1/4" 1150 lbs. S Pressure

  17. A high performance field-reversed configuration

    SciTech Connect

    Binderbauer, M. W.; Tajima, T.; Steinhauer, L. C.; Garate, E.; Tuszewski, M.; Smirnov, A.; Gota, H.; Barnes, D.; Deng, B. H.; Thompson, M. C.; Trask, E.; Yang, X.; Putvinski, S.; Rostoker, N.; Andow, R.; Aefsky, S.; Bolte, N.; Bui, D. Q.; Ceccherini, F.; Clary, R.; and others

    2015-05-15

    Conventional field-reversed configurations (FRCs), high-beta, prolate compact toroids embedded in poloidal magnetic fields, face notable stability and confinement concerns. These can be ameliorated by various control techniques, such as introducing a significant fast ion population. Indeed, adding neutral beam injection into the FRC over the past half-decade has contributed to striking improvements in confinement and stability. Further, the addition of electrically biased plasma guns at the ends, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence-driven losses and greatly improved stability. Together, these enabled the build-up of a well-confined and dominant fast-ion population. Under such conditions, highly reproducible, macroscopically stable hot FRCs (with total plasma temperature of ∼1 keV) with record lifetimes were achieved. These accomplishments point to the prospect of advanced, beam-driven FRCs as an intriguing path toward fusion reactors. This paper reviews key results and presents context for further interpretation.

  18. High-performance silicon nanowire bipolar phototransistors

    NASA Astrophysics Data System (ADS)

    Tan, Siew Li; Zhao, Xingyan; Chen, Kaixiang; Crozier, Kenneth B.; Dan, Yaping

    2016-07-01

    Silicon nanowires (SiNWs) have emerged as sensitive absorbing materials for photodetection at wavelengths ranging from ultraviolet (UV) to the near infrared. Most of the reports on SiNW photodetectors are based on photoconductor, photodiode, or field-effect transistor device structures. These SiNW devices each have their own advantages and trade-offs in optical gain, response time, operating voltage, and dark current noise. Here, we report on the experimental realization of single SiNW bipolar phototransistors on silicon-on-insulator substrates. Our SiNW devices are based on bipolar transistor structures with an optically injected base region and are fabricated using CMOS-compatible processes. The experimentally measured optoelectronic characteristics of the SiNW phototransistors are in good agreement with simulation results. The SiNW phototransistors exhibit significantly enhanced response to UV and visible light, compared with typical Si p-i-n photodiodes. The near infrared responsivities of the SiNW phototransistors are comparable to those of Si avalanche photodiodes but are achieved at much lower operating voltages. Compared with other reported SiNW photodetectors as well as conventional bulk Si photodiodes and phototransistors, the SiNW phototransistors in this work demonstrate the combined advantages of high gain, high photoresponse, low dark current, and low operating voltage.

  19. A high performance field-reversed configurationa)

    NASA Astrophysics Data System (ADS)

    Binderbauer, M. W.; Tajima, T.; Steinhauer, L. C.; Garate, E.; Tuszewski, M.; Schmitz, L.; Guo, H. Y.; Smirnov, A.; Gota, H.; Barnes, D.; Deng, B. H.; Thompson, M. C.; Trask, E.; Yang, X.; Putvinski, S.; Rostoker, N.; Andow, R.; Aefsky, S.; Bolte, N.; Bui, D. Q.; Ceccherini, F.; Clary, R.; Cheung, A. H.; Conroy, K. D.; Dettrick, S. A.; Douglass, J. D.; Feng, P.; Galeotti, L.; Giammanco, F.; Granstedt, E.; Gupta, D.; Gupta, S.; Ivanov, A. A.; Kinley, J. S.; Knapp, K.; Korepanov, S.; Hollins, M.; Magee, R.; Mendoza, R.; Mok, Y.; Necas, A.; Primavera, S.; Onofri, M.; Osin, D.; Rath, N.; Roche, T.; Romero, J.; Schroeder, J. H.; Sevier, L.; Sibley, A.; Song, Y.; Van Drie, A. D.; Walters, J. K.; Waggoner, W.; Yushmanov, P.; Zhai, K.

    2015-05-01

    Conventional field-reversed configurations (FRCs), high-beta, prolate compact toroids embedded in poloidal magnetic fields, face notable stability and confinement concerns. These can be ameliorated by various control techniques, such as introducing a significant fast ion population. Indeed, adding neutral beam injection into the FRC over the past half-decade has contributed to striking improvements in confinement and stability. Further, the addition of electrically biased plasma guns at the ends, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence-driven losses and greatly improved stability. Together, these enabled the build-up of a well-confined and dominant fast-ion population. Under such conditions, highly reproducible, macroscopically stable hot FRCs (with total plasma temperature of ˜1 keV) with record lifetimes were achieved. These accomplishments point to the prospect of advanced, beam-driven FRCs as an intriguing path toward fusion reactors. This paper reviews key results and presents context for further interpretation.

  20. High performance computing for beam physics applications

    SciTech Connect

    Ryne, R.D.; Habib, S.

    1994-09-01

    Several countries are now involved in efforts aimed at utilizing accelerator-driven technologies to solve problems of national and international importance. These technologies have both economic and environmental implications. The technologies include waste transmutation, plutonium conversion, neutron production for materials science and biological science research, neutron production for fusion materials testing, fission energy production systems, and tritium production. All of these projects require a high-intensity linear accelerator that operates with extremely low beam loss. This presents a formidable computational challenge: One must design and optimize over a kilometer of complex accelerating structures while taking into account beam loss to an accuracy of 10 parts per billion per meter. Such modeling is essential if one is to have confidence that the accelerator will meet its beam loss requirement, which ultimately affects system reliability, safety and cost. At Los Alamos, the authors are developing a capability to model ultra-low loss accelerators using the CM-5 at the Advanced Computing Laboratory. They are developing PIC, Vlasov/Poisson, and Langevin/Fokker-Planck codes for this purpose. With slight modification, they have also applied their codes to modeling mesoscopic systems and astrophysical systems. In this paper, they will first describe HPC activities in the accelerator community. Then they will discuss the tools they have developed to model classical and quantum evolution equations. Lastly they will describe how these tools have been used to study beam halo in high current, mismatched charged particle beams.

  1. Development of high performance hybrid rocket fuels

    NASA Astrophysics Data System (ADS)

    Zaseck, Christopher R.

    . In order to examine paraffin/additive combustion in a motor environment, I conducted experiments on well characterized aluminum based additives. In particular, I investigate the influence of aluminum, unpassivated aluminum, milled aluminum/polytetrafluoroethylene (PTFE), and aluminum hydride on the performance of paraffin fuels for hybrid rocket propulsion. I use an optically accessible combustor to examine the performance of the fuel mixtures in terms of characteristic velocity efficiency and regression rate. Each combustor test consumes a 12.7 cm long, 1.9 cm diameter fuel strand under 160 kg/m 2s of oxygen at up to 1.4 MPa. The experimental results indicate that the addition of 5 wt.% 30 mum or 80 nm aluminum to paraffin increases the regression rate by approximately 15% compared to neat paraffin grains. At higher aluminum concentrations and nano-scale particles sizes, the increased melt layer viscosity causes slower regression. Alane and Al/PTFE at 12.5 wt.% increase the regression of paraffin by 21% and 32% respectively. Finally, an aging study indicates that paraffin can protect air and moisture sensitive particles from oxidation. The opposed burner and aluminum/paraffin hybrid rocket experiments show that additives can alter bulk fuel properties, such as viscosity, that regulate entrainment. The general effect of melt layer properties on the entrainment and regression rate of paraffin is not well understood. Improved understanding of how solid additives affect the properties and regression of paraffin is essential to maximize performance. In this document I investigate the effect of melt layer properties on paraffin regression using inert additives. Tests are performed in the optical cylindrical combustor at ˜1 MPa under a gaseous oxygen mass flux of ˜160 kg/m2s. The experiments indicate that the regression rate is proportional to mu0.08rho 0.38kappa0.82. In addition, I explore how to predict fuel viscosity, thermal conductivity, and density prior to testing

  2. Toward a new metric for ranking high performance computing systems.

    SciTech Connect

    Heroux, Michael Allen; Dongarra, Jack.

    2013-06-01

    The High Performance Linpack (HPL), or Top 500, benchmark [1] is the most widely recognized and discussed metric for ranking high performance computing systems. However, HPL is increasingly unreliable as a true measure of system performance for a growing collection of important science and engineering applications. In this paper we describe a new high performance conjugate gradient (HPCG) benchmark. HPCG is composed of computations and data access patterns more commonly found in applications. Using HPCG we strive for a better correlation to real scientific application performance and expect to drive computer system design and implementation in directions that will better impact performance improvement.

  3. High performance composite tubes for offshore applications

    NASA Astrophysics Data System (ADS)

    Tamarelle, P. J. C.; Sparks, C. P.

    1987-10-01

    The technical aspects of composite tubes are introduced through a series of typical oilfield tubular applications describing design and tests results. The tubes are composed of several layers with independant functions. Structural layers made of high resistance fibers set in a resin matrix, are filament wound and consist of circumferential layers, perpendicular to the tube axis, to resist bursting stresses and longitudinal layers, helically wound, to resist axial forces. The tubes are completed with internal and external liners and are terminated at extremities by steel end pieces to which the composite layers are bonded. Advantages and potential cost savings resulting from the replacement of a conventional steel riser by a composite riser are analyzed for a tension leg platform (TLP) in different water depths, combining the effects on cost of top tension, deck weight, hull size, and mooring loads.

  4. High-Performance Energy Applications and Systems

    SciTech Connect

    Miller, Barton

    2014-01-01

    The Paradyn project has a history of developing algorithms, techniques, and software that push the cutting edge of tool technology for high-end computing systems. Under this funding, we are working on a three-year agenda to make substantial new advances in support of new and emerging Petascale systems. The overall goal for this work is to address the steady increase in complexity of these petascale systems. Our work covers two key areas: (1) The analysis, instrumentation and control of binary programs. Work in this area falls under the general framework of the Dyninst API tool kits. (2) Infrastructure for building tools and applications at extreme scale. Work in this area falls under the general framework of the MRNet scalability framework. Note that work done under this funding is closely related to work done under a contemporaneous grant, “Foundational Tools for Petascale Computing”, SC0003922/FG02-10ER25940, UW PRJ27NU.

  5. Realization of high performance random laser diodes

    NASA Astrophysics Data System (ADS)

    Yu, S. F.

    2011-03-01

    For the past four decades, extensive studies have been concentrated on the understanding of the physics of random lasing phenomena in scattering media with optical gain. Although lasing modes can be excited from the mirrorless scattering media, the characteristics of high scattering loss, multiple-direction emission, as well as multiple-mode oscillation prohibited them to be used as practical laser cavities. Furthermore, due to the difficulty of achieving high optical gain under electrical excitation, electrical excitation of random lasing action was seldom reported. Hence, mirrorless random cavities have never been used to realize lasers for practical applications -- CD, DVD, pico-projector, etc. Nowadays, studies of random lasing are still limited to the scientific research. Recently, the difficulty of achieving `battery driven' random laser diodes has been overcome by using nano-structured ZnO as the random medium and the careful design of heterojunctions. This lead to the first demonstration of room-temperature electrically pumped random lasing action under continuity wave and pulsed operation. In this presentation, we proposed to realize an array of quasi-one dimensional ZnO random laser diodes. We can show that if the laser array can be manipulated in a way such that every individual random laser can be coupled laterally to and locked with a particular phase relationship to its adjacent neighbor, the laser array can obtain coherent addition of random modes. Hence, output power can be multiplied and one lasing mode will only be supported due to the repulsion characteristics of random modes. This work was supported by HK PolyU grant no. 1-ZV6X.

  6. Complex Suspension Rheology Using High Performance Computing

    NASA Astrophysics Data System (ADS)

    Heine, David

    In processing advanced ceramic materials, the properties of the final product depend on the process conditions and the interactions between the materials at the scale of the individual particles. Along with general bulk properties, more subtle properties including particle orientation, segregation, and pore structure must be established during processing to achieve the desired functionality. Accomplishing this requires a thorough understanding of the mesoscale interactions and how they influence the macroscale behavior. We conduct a series of large scale simulations of highly filled polymer-nanoparticle composites as analogs of ceramic pastes and reveal how the ceramic particle and binder properties determine the structure and rheology of the bulk material. As with real ceramic pastes, particle shape and size distribution along with composition determine the shear modulus, extent of segregation, and degree of particle alignment. These factors are influenced by the binder through the rheology of the binder phase and the interaction between binder and particles. This talk presents the results of this study of polymer-nanoparticle composites along with a brief overview of research and development at Corning showing the similarities and differences between research in industry and academia.

  7. Three-dimensional and dynamical performance of a molten carbonate fuel cell stack

    SciTech Connect

    He, W.; Chen, Q.

    1996-12-31

    The three-dimensional and dynamic performance of a molten carbonate fuel cell (MCFC) stack operating under load-following modes have been investigated by using dynamic simulation. The major processes with regard to an MCFC`s safe and efficient operation in power-generation systems, such as the mass and heat transport, chemical reactions and electrical power generation, are formulated in a three-dimensional, time-dependent form using the computational-fluid-dynamics (CFD) technique. The grid definitions have been explained, and a simple test to determine whether the simulation results being acceptable has been introduced. In this paper, the model performance is demonstrated by applying it to calculate the distributions of current density and temperature under a step change.

  8. A History of High-Performance Computing

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Faster than most speedy computers. More powerful than its NASA data-processing predecessors. Able to leap large, mission-related computational problems in a single bound. Clearly, it s neither a bird nor a plane, nor does it need to don a red cape, because it s super in its own way. It's Columbia, NASA s newest supercomputer and one of the world s most powerful production/processing units. Named Columbia to honor the STS-107 Space Shuttle Columbia crewmembers, the new supercomputer is making it possible for NASA to achieve breakthroughs in science and engineering, fulfilling the Agency s missions, and, ultimately, the Vision for Space Exploration. Shortly after being built in 2004, Columbia achieved a benchmark rating of 51.9 teraflop/s on 10,240 processors, making it the world s fastest operational computer at the time of completion. Putting this speed into perspective, 20 years ago, the most powerful computer at NASA s Ames Research Center, home of the NASA Advanced Supercomputing Division (NAS), ran at a speed of about 1 gigaflop (one billion calculations per second). The Columbia supercomputer is 50,000 times faster than this computer and offers a tenfold increase in capacity over the prior system housed at Ames. What s more, Columbia is considered the world s largest Linux-based, shared-memory system. The system is offering immeasurable benefits to society and is the zenith of years of NASA/private industry collaboration that has spawned new generations of commercial, high-speed computing systems.

  9. Vortices in high-performance high-temperature superconductors

    NASA Astrophysics Data System (ADS)

    Kwok, Wai-Kwong; Welp, Ulrich; Glatz, Andreas; Koshelev, Alexei E.; Kihlstrom, Karen J.; Crabtree, George W.

    2016-11-01

    The behavior of vortex matter in high-temperature superconductors (HTS) controls the entire electromagnetic response of the material, including its current carrying capacity. Here, we review the basic concepts of vortex pinning and its application to a complex mixed pinning landscape to enhance the critical current and to reduce its anisotropy. We focus on recent scientific advances that have resulted in large enhancements of the in-field critical current in state-of-the-art second generation (2G) YBCO coated conductors and on the prospect of an isotropic, high-critical current superconductor in the iron-based superconductors. Lastly, we discuss an emerging new paradigm of critical current by design—a drive to achieve a quantitative correlation between the observed critical current density and mesoscale mixed pinning landscapes by using realistic input parameters in an innovative and powerful large-scale time dependent Ginzburg-Landau approach to simulating vortex dynamics.

  10. Vortices in high-performance high-temperature superconductors.

    PubMed

    Kwok, Wai-Kwong; Welp, Ulrich; Glatz, Andreas; Koshelev, Alexei E; Kihlstrom, Karen J; Crabtree, George W

    2016-11-01

    The behavior of vortex matter in high-temperature superconductors (HTS) controls the entire electromagnetic response of the material, including its current carrying capacity. Here, we review the basic concepts of vortex pinning and its application to a complex mixed pinning landscape to enhance the critical current and to reduce its anisotropy. We focus on recent scientific advances that have resulted in large enhancements of the in-field critical current in state-of-the-art second generation (2G) YBCO coated conductors and on the prospect of an isotropic, high-critical current superconductor in the iron-based superconductors. Lastly, we discuss an emerging new paradigm of critical current by design-a drive to achieve a quantitative correlation between the observed critical current density and mesoscale mixed pinning landscapes by using realistic input parameters in an innovative and powerful large-scale time dependent Ginzburg-Landau approach to simulating vortex dynamics.

  11. High Performance Liquid Chromatography/Video Fluorometry. Part II. Applications.

    DTIC Science & Technology

    1981-09-30

    HIGH PERFORMANCE LIQUID CHROMATOGRAPHY /VIDEO FLUOROMETRY. PART...REP«T_N&:-ŗ/ High Performance Liquid Chromatography /Video Fluorometry» Part II. Applications« by | Dennis C./Shelly* Michael P./Vogarty and...Data EnlirtdJ REPORT DOCUMENTATION PAGE t. REPORT NUMBER 2 GOVT ACCESSION NO 4. T1TI.F (and Submit) lP-^fffsyva High Performance Liquid Chromatography

  12. Mitigating project risk by use of high performance collector technology

    NASA Astrophysics Data System (ADS)

    Richert, Timo; Riffelmann, Klaus-Jürgen; Nava, Paul

    2016-05-01

    Collectors with a high optical quality are generally valued for their additional performance, i.e. the expected additional output due to the performance gain compared to a lower quality reference collector. However, high-performance collectors additionally have a lower sensitivity to additional optical errors and, thus not only perform better nominally, but are also more likely to reach their nominal performance even when project uncertainties (e.g. increased sun-shape) or quality issues (e.g. increased component optical error) degrade their performance. This has physical reasons, whose cause and effect will be described and quantified within this paper.

  13. High performance interconnection between high data rate networks

    NASA Technical Reports Server (NTRS)

    Foudriat, E. C.; Maly, K.; Overstreet, C. M.; Zhang, L.; Sun, W.

    1992-01-01

    The bridge/gateway system needed to interconnect a wide range of computer networks to support a wide range of user quality-of-service requirements is discussed. The bridge/gateway must handle a wide range of message types including synchronous and asynchronous traffic, large, bursty messages, short, self-contained messages, time critical messages, etc. It is shown that messages can be classified into three basic classes, synchronous and large and small asynchronous messages. The first two require call setup so that packet identification, buffer handling, etc. can be supported in the bridge/gateway. Identification enables resequences in packet size. The third class is for messages which do not require call setup. Resequencing hardware based to handle two types of resequencing problems is presented. The first is for a virtual parallel circuit which can scramble channel bytes. The second system is effective in handling both synchronous and asynchronous traffic between networks with highly differing packet sizes and data rates. The two other major needs for the bridge/gateway are congestion and error control. A dynamic, lossless congestion control scheme which can easily support effective error correction is presented. Results indicate that the congestion control scheme provides close to optimal capacity under congested conditions. Under conditions where error may develop due to intervening networks which are not lossless, intermediate error recovery and correction takes 1/3 less time than equivalent end-to-end error correction under similar conditions.

  14. Performance of an internal reforming molten carbonate fuel cell supplied with ethanol/water mixture

    SciTech Connect

    Freni, S.; Maggio, G.; Barone, F.

    1996-12-31

    The state of an on the field of molten carbonate fuel cell (MCFC) systems covers many technological aspects related to the use of these systems for the production of electricity. In this respect, extensive research efforts have been made to develop a technology using the methane based on the steam reforming process, and different configurations have been analyzed and their performance determined for several operative cell conditions. However, the operative temperature (T-923 K) of the MCFC. that allows the direct conversion of hydrocarbons or alcohols into H{sub 2} and CO, promotes researches in the field of alternative fuels, more easily transported and reformed compared to methane. In this paper are described the most indicative results obtained by a study that considers the use of water/ethanol mixture as an attractive alternative to the methane for a molten carbonate fuel cell.

  15. A Theoretical Structure of High School Concert Band Performance

    ERIC Educational Resources Information Center

    Bergee, Martin J.

    2015-01-01

    This study used exploratory (EFA) and confirmatory factor analysis (CFA) to verify a theoretical structure for high school concert band performance and to test that structure for viability, generality, and invariance. A total of 101 university students enrolled in two different bands rated two high school band performances (a "first"…

  16. Building Synergy: The Power of High Performance Work Systems.

    ERIC Educational Resources Information Center

    Gephart, Martha A.; Van Buren, Mark E.

    1996-01-01

    Suggests that high-performance work systems create the synergy that lets companies gain and keep a competitive advantage. Identifies the components of high-performance work systems and critical action steps for implementation. Describes the results companies such as Xerox, Lever Brothers, and Corning Incorporated have achieved by using them. (JOW)

  17. 24 CFR 902.71 - Incentives for high performers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... reviews and less monitoring), effective upon notification of high performer designation. (ii) The... points in funding competitions. A high performer PHA will be eligible for bonus points in HUD's funding competitions, where such bonus points are not restricted by statute or regulation governing the funding...

  18. Rotordynamic Instability Problems in High-Performance Turbomachinery

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Rotordynamics and predictions on the stability of characteristics of high performance turbomachinery were discussed. Resolutions of problems on experimental validation of the forces that influence rotordynamics were emphasized. The programs to predict or measure forces and force coefficients in high-performance turbomachinery are illustrated. Data to design new machines with enhanced stability characteristics or upgrading existing machines are presented.

  19. An Analysis of a High Performing School District's Culture

    ERIC Educational Resources Information Center

    Corum, Kenneth D.; Schuetz, Todd B.

    2012-01-01

    This report describes a problem based learning project focusing on the cultural elements of a high performing school district. Current literature on school district culture provides numerous cultural elements that are present in high performing school districts. With the current climate in education placing pressure on school districts to perform…

  20. Effects of High Terrestrial Altitude on Military Performance

    DTIC Science & Technology

    1989-04-18

    Title Effects of High Terrestrial Altitude on Military Performance Author( s ) Louis E. Banderet and Richard L. Burse Intended for publication in Handbook...34’- <-𔃾 DA UJ 2496 PRIVOUS EDITIONS WILL II USED C . S fnt Effects of High Terrestrial Altitude on Military Performance 1 2 Louis E. Banderet...inadequate oxygen which can ad- versely affect military performance ( Disease threat, 1979; U.S. Army, 1975). Much information of military importance about

  1. High Performance Walls in Hot-Dry Climates

    SciTech Connect

    Hoeschele, Marc; Springer, David; Dakin, Bill; German, Alea

    2015-01-01

    High performance walls represent a high priority measure for moving the next generation of new homes to the Zero Net Energy performance level. The primary goal in improving wall thermal performance revolves around increasing the wall framing from 2x4 to 2x6, adding more cavity and exterior rigid insulation, achieving insulation installation criteria meeting ENERGY STAR's thermal bypass checklist, and reducing the amount of wood penetrating the wall cavity.

  2. High performance pipelined multiplier with fast carry-save adder

    NASA Technical Reports Server (NTRS)

    Wu, Angus

    1990-01-01

    A high-performance pipelined multiplier is described. Its high performance results from the fast carry-save adder basic cell which has a simple structure and is suitable for the Gate Forest semi-custom environment. The carry-save adder computes the sum and carry within two gate delay. Results show that the proposed adder can operate at 200 MHz for a 2-micron CMOS process; better performance is expected in a Gate Forest realization.

  3. Los Alamos National Laboratory's high-performance data system

    SciTech Connect

    Mercier, C.; Chorn, G.; Christman, R.; Collins, B.

    1991-01-01

    Los Alamos National Laboratory is designing a High-Performance Data System (HPDS) that will provide storage for supercomputers requiring large files and fast transfer speeds. The HPDS will meet the performance requirements by managing data transfers from high-speed storage systems connected directly to a high-speed network. File and storage management software will be distributed in workstations. Network protocols will ensure reliable, wide-area network data delivery to support long-distance distributed processing. 3 refs., 2 figs.

  4. High performance thermal imaging for the 21st century

    NASA Astrophysics Data System (ADS)

    Clarke, David J.; Knowles, Peter

    2003-01-01

    In recent years IR detector technology has developed from early short linear arrays. Such devices require high performance signal processing electronics to meet today's thermal imaging requirements for military and para-military applications. This paper describes BAE SYSTEMS Avionics Group's Sensor Integrated Modular Architecture thermal imager which has been developed alongside the group's Eagle 640×512 arrays to provide high performance imaging capability. The electronics architecture also supprots High Definition TV format 2D arrays for future growth capability.

  5. Design method of water jet pump towards high cavitation performances

    NASA Astrophysics Data System (ADS)

    Cao, L. L.; Che, B. X.; Hu, L. J.; Wu, D. Z.

    2016-05-01

    As one of the crucial components for power supply, the propulsion system is of great significance to the advance speed, noise performances, stabilities and other associated critical performances of underwater vehicles. Developing towards much higher advance speed, the underwater vehicles make more critical demands on the performances of the propulsion system. Basically, the increased advance speed requires the significantly raised rotation speed of the propulsion system, which would result in the deteriorated cavitation performances and consequently limit the thrust and efficiency of the whole system. Compared with the traditional propeller, the water jet pump offers more favourite cavitation, propulsion efficiency and other associated performances. The present research focuses on the cavitation performances of the waterjet pump blade profile in expectation of enlarging its advantages in high-speed vehicle propulsion. Based on the specifications of a certain underwater vehicle, the design method of the waterjet blade with high cavitation performances was investigated in terms of numerical simulation.

  6. The Processing and Mechanical Properties of High Temperature/High Performance Composites. Book 3. Constituent Properties and Macroscopic Performance: MMCs

    DTIC Science & Technology

    1993-04-01

    April 1993 "DTIC ELECTE-NJUN21 9199 The Processing and Mechanical Properties of High Temperature/ High Performance Composites by A.G. Evans & F. Leckie...CONSTITUENT PROPERTIES AND MACROSCOPIC PERFORMANCE: MMCs SUMMARY OF TABLE OF CONTENTS EXECUTIVE SUMMARY BOOK 1: CONSTITUENT PROPERTIES OF COMPOSITES ...PROPERTIES AND MACROSCOPIC PERFORMANCE: MMCs 34. Mode I Fatigue Cracking in a Fiber D.P. Walls Reinforced Metal Matrix Composite G. Bao F.W. Zok 35

  7. High Performance Work System, HRD Climate and Organisational Performance: An Empirical Study

    ERIC Educational Resources Information Center

    Muduli, Ashutosh

    2015-01-01

    Purpose: This paper aims to study the relationship between high-performance work system (HPWS) and organizational performance and to examine the role of human resource development (HRD) Climate in mediating the relationship between HPWS and the organizational performance in the context of the power sector of India. Design/methodology/approach: The…

  8. High School Employment, School Performance, and College Entry

    ERIC Educational Resources Information Center

    Lee, Chanyoung; Orazem, Peter F.

    2010-01-01

    The proportion of U.S. high school students working during the school year ranges from 23% in the freshman year to 75% in the senior year. This study estimates how cumulative work histories during the high school years affect probability of dropout, high school academic performance, and the probability of attending college. Variations in…

  9. Evaluation of GPFS Connectivity Over High-Performance Networks

    SciTech Connect

    Srinivasan, Jay; Canon, Shane; Andrews, Matthew

    2009-02-17

    We present the results of an evaluation of new features of the latest release of IBM's GPFS filesystem (v3.2). We investigate different ways of connecting to a high-performance GPFS filesystem from a remote cluster using Infiniband (IB) and 10 Gigabit Ethernet. We also examine the performance of the GPFS filesystem with both serial and parallel I/O. Finally, we also present our recommendations for effective ways of utilizing high-bandwidth networks for high-performance I/O to parallel file systems.

  10. Tiny biomedical amplifier combines high performance, low power drain

    NASA Technical Reports Server (NTRS)

    Deboo, G. J.

    1965-01-01

    Transistorized, portable, high performance amplifier with low power drain facilitates biomedical studies on mobile subjects. This device, which utilizes a differential input to obtain a common-mode rejection, is used for amplifying electrocardiogram and electromyogram signals.

  11. High-temperature alloys: Single-crystal performance boost

    NASA Astrophysics Data System (ADS)

    Schütze, Michael

    2016-08-01

    Titanium aluminide alloys are lightweight and have attractive properties for high-temperature applications. A new growth method that enables single-crystal production now boosts their mechanical performance.

  12. High Performance Schools--It's a No-Brainer.

    ERIC Educational Resources Information Center

    Nicklas, Mike

    2002-01-01

    A North Carolina middle school demonstrates that high performance, sustainable school buildings cost no more to build and are more comfortable and productive learning environments than conventional buildings. (Author)

  13. Energy Design Guidelines for High Performance Schools: Tropical Island Climates

    SciTech Connect

    2004-11-01

    Design guidelines outline high performance principles for the new or retrofit design of K-12 schools in tropical island climates. By incorporating energy improvements into construction or renovation plans, schools can reduce energy consumption and costs.

  14. Rotordynamic Instability Problems in High-Performance Turbomachinery

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Rotor dynamic instability problems in high performance turbomachinery are reviewed. Mechanical instability mechanisms are discussed. Seal forces and working fluid forces in turbomachinery are discussed. Control of rotor instability is also investigated.

  15. Exploring KM Features of High-Performance Companies

    NASA Astrophysics Data System (ADS)

    Wu, Wei-Wen

    2007-12-01

    For reacting to an increasingly rival business environment, many companies emphasize the importance of knowledge management (KM). It is a favorable way to explore and learn KM features of high-performance companies. However, finding out the critical KM features of high-performance companies is a qualitative analysis problem. To handle this kind of problem, the rough set approach is suitable because it is based on data-mining techniques to discover knowledge without rigorous statistical assumptions. Thus, this paper explored KM features of high-performance companies by using the rough set approach. The results show that high-performance companies stress the importance on both tacit and explicit knowledge, and consider that incentives and evaluations are the essentials to implementing KM.

  16. A DRAM compiler algorithm for high performance VLSI embedded memories

    NASA Technical Reports Server (NTRS)

    Eldin, A. G.

    1992-01-01

    In many applications, the limited density of the embedded SRAM does not allow integrating the memory on the same chip with other logic and functional blocks. In such cases, the embedded DRAM provides the optimum combination of very high density, low power, and high performance. For ASIC's to take full advantage of this design strategy, an efficient and highly reliable DRAM compiler must be used. The embedded DRAM architecture, cell, and peripheral circuit design considerations and the algorithm of a high performance memory compiler are presented .

  17. High performances from a new design of crystal oscillator

    NASA Astrophysics Data System (ADS)

    Beuvy, G.; Marotel, G.; Renoult, P.

    1985-04-01

    This paper describes new designs developed and applied in order to increase the performance of crystal oscillators for military and space applications, requiring high performance. Results have been obtained from: (1) the developments of a new technology applied to crystal resonators; (2) the use of a low noise design of the electronics associated with the resonator; (3) highly miniaturized oven with PID control; and (4) assembly of these elements have met these specifications during mechanical environment tests.

  18. Variational formulation of high performance finite elements: Parametrized variational principles

    NASA Technical Reports Server (NTRS)

    Felippa, Carlos A.; Militello, Carmello

    1991-01-01

    High performance elements are simple finite elements constructed to deliver engineering accuracy with coarse arbitrary grids. This is part of a series on the variational basis of high-performance elements, with emphasis on those constructed with the free formulation (FF) and assumed natural strain (ANS) methods. Parametrized variational principles that provide a foundation for the FF and ANS methods, as well as for a combination of both are presented.

  19. Development of Synthetic Spider Silk Fibers for High Performance Applications

    DTIC Science & Technology

    2013-08-08

    the conditions for syringe pump extrusion of silk fibers often seen in literature do not translate to industrial scale wet spinning. The magnitudes...REPORT Development of Synthetic Spider Silk Fibers for High Performance Applications 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: The overall goal of...this project is to demonstrate the feasibility of synthetic production of high-performance spider silk fibers for use in next-generation automotives

  20. The cyclic fatigue of high-performance fibers

    NASA Astrophysics Data System (ADS)

    Kerr, M.; Chawla, N.; Chawla, K. K.

    2005-02-01

    High-performance fibers are virtually ubiquitous in our everyday lives. In a variety of structural applications, fibers and fiber-reinforced composites are subjected to cyclic mechanical loading. This paper reviews the fatigue behavior of some common high-performance fibers such as polymer, metal, and ceramic fibers. Fatigue mechanisms unique to each type of fiber are identified and a description of fatigue damage and fracture is provided.

  1. Optical Thermal Characterization Enables High-Performance Electronics Applications

    SciTech Connect

    2016-02-01

    NREL developed a modeling and experimental strategy to characterize thermal performance of materials. The technique provides critical data on thermal properties with relevance for electronics packaging applications. Thermal contact resistance and bulk thermal conductivity were characterized for new high-performance materials such as thermoplastics, boron-nitride nanosheets, copper nanowires, and atomically bonded layers. The technique is an important tool for developing designs and materials that enable power electronics packaging with small footprint, high power density, and low cost for numerous applications.

  2. High Performance Skiing. How to Become a Better Alpine Skier.

    ERIC Educational Resources Information Center

    Yacenda, John

    This book is intended for people who desire to improve their skiing by exploring high performance techniques leading to: (1) more consistent performance; (2) less fatigue and more endurance; (3) greater strength and flexibility; (4) greater versatility; (5) greater confidence in all skiing conditions; and (6) the knowledge to participate in…

  3. Two Profiles of the Dutch High Performing Employee

    ERIC Educational Resources Information Center

    de Waal, A. A.; Oudshoorn, Michella

    2015-01-01

    Purpose: The purpose of this study is to explore the profile of an ideal employee, to be more precise the behavioral characteristics of the Dutch high-performing employee (HPE). Organizational performance depends for a large part on the commitment of employees. Employees provide their knowledge, skills, experiences and creativity to the…

  4. Manufacturing Advantage: Why High-Performance Work Systems Pay Off.

    ERIC Educational Resources Information Center

    Appelbaum, Eileen; Bailey, Thomas; Berg, Peter; Kalleberg, Arne L.

    A study examined the relationship between high-performance workplace practices and the performance of plants in the following manufacturing industries: steel, apparel, and medical electronic instruments and imaging. The multilevel research methodology combined the following data collection activities: (1) site visits; (2) collection of plant…

  5. Teacher Performance Trajectories in High- and Lower-Poverty Schools

    ERIC Educational Resources Information Center

    Xu, Zeyu; Özek, Umut; Hansen, Michael

    2015-01-01

    This study explores whether teacher performance trajectory over time differs by school-poverty settings. Focusing on elementary school mathematics teachers in North Carolina and Florida, we find no systematic relationship between school student poverty rates and teacher performance trajectories. In both high- (=60% free/reduced-price lunch [FRPL])…

  6. High-Performance Java Codes for Computational Fluid Dynamics

    NASA Technical Reports Server (NTRS)

    Riley, Christopher; Chatterjee, Siddhartha; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    The computational science community is reluctant to write large-scale computationally -intensive applications in Java due to concerns over Java's poor performance, despite the claimed software engineering advantages of its object-oriented features. Naive Java implementations of numerical algorithms can perform poorly compared to corresponding Fortran or C implementations. To achieve high performance, Java applications must be designed with good performance as a primary goal. This paper presents the object-oriented design and implementation of two real-world applications from the field of Computational Fluid Dynamics (CFD): a finite-volume fluid flow solver (LAURA, from NASA Langley Research Center), and an unstructured mesh adaptation algorithm (2D_TAG, from NASA Ames Research Center). This work builds on our previous experience with the design of high-performance numerical libraries in Java. We examine the performance of the applications using the currently available Java infrastructure and show that the Java version of the flow solver LAURA performs almost within a factor of 2 of the original procedural version. Our Java version of the mesh adaptation algorithm 2D_TAG performs within a factor of 1.5 of its original procedural version on certain platforms. Our results demonstrate that object-oriented software design principles are not necessarily inimical to high performance.

  7. Configuration and performance of fuel cell-combined cycle options

    SciTech Connect

    Rath, L.K.; Le, P.H.; Sudhoff, F.A.

    1995-12-31

    The natural gas, indirect-fired, carbonate fuel-cell-bottomed, combined cycle (NG-IFCFC) and the topping natural-gas/solid-oxide fuel-cell combined cycle (NG-SOFCCC) are introduced as novel power-plant systems for the distributed power and on-site markets in the 20-200 mega-watt (MW) size range. The novel NG-IFCFC power-plant system configures the ambient pressure molten-carbonate fuel cell (MCFC) with a gas turbine, air compressor, combustor, and ceramic heat exchanger: The topping solid-oxide fuel-cell (SOFC) combined cycle is not new. The purpose of combining a gas turbine with a fuel cell was to inject pressurized air into a high-pressure fuel cell and to reduce the size, and thereby, to reduce the cost of the fuel cell. Today, the SOFC remains pressurized, but excess chemical energy is combusted and the thermal energy is utilized by the Carnot cycle heat engine to complete the system. ASPEN performance results indicate efficiencies and heat rates for the NG-IFCFC or NG-SOFCCC are better than conventional fuel cell or gas turbine steam-bottomed cycles, but with smaller and less expensive components. Fuel cell and gas turbine systems should not be viewed as competitors, but as an opportunity to expand to markets where neither gas turbines nor fuel cells alone would be commercially viable. Non-attainment areas are the most likely markets.

  8. High skin temperature and hypohydration impair aerobic performance.

    PubMed

    Sawka, Michael N; Cheuvront, Samuel N; Kenefick, Robert W

    2012-03-01

    This paper reviews the roles of hot skin (>35°C) and body water deficits (>2% body mass; hypohydration) in impairing submaximal aerobic performance. Hot skin is associated with high skin blood flow requirements and hypohydration is associated with reduced cardiac filling, both of which act to reduce aerobic reserve. In euhydrated subjects, hot skin alone (with a modest core temperature elevation) impairs submaximal aerobic performance. Conversely, aerobic performance is sustained with core temperatures >40°C if skin temperatures are cool-warm when euhydrated. No study has demonstrated that high core temperature (∼40°C) alone, without coexisting hot skin, will impair aerobic performance. In hypohydrated subjects, aerobic performance begins to be impaired when skin temperatures exceed 27°C, and even warmer skin exacerbates the aerobic performance impairment (-1.5% for each 1°C skin temperature). We conclude that hot skin (high skin blood flow requirements from narrow skin temperature to core temperature gradients), not high core temperature, is the 'primary' factor impairing aerobic exercise performance when euhydrated and that hypohydration exacerbates this effect.

  9. The architecture of the High Performance Storage System (HPSS)

    NASA Technical Reports Server (NTRS)

    Teaff, Danny; Watson, Dick; Coyne, Bob

    1994-01-01

    The rapid growth in the size of datasets has caused a serious imbalance in I/O and storage system performance and functionality relative to application requirements and the capabilities of other system components. The High Performance Storage System (HPSS) is a scalable, next-generation storage system that will meet the functionality and performance requirements or large-scale scientific and commercial computing environments. Our goal is to improve the performance and capacity of storage by two orders of magnitude or more over what is available in the general or mass marketplace today. We are also providing corresponding improvements in architecture and functionality. This paper describes the architecture and functionality of HPSS.

  10. A Component Architecture for High-Performance Computing

    SciTech Connect

    Bernholdt, D E; Elwasif, W R; Kohl, J A; Epperly, T G W

    2003-01-21

    The Common Component Architecture (CCA) provides a means for developers to manage the complexity of large-scale scientific software systems and to move toward a ''plug and play'' environment for high-performance computing. The CCA model allows for a direct connection between components within the same process to maintain performance on inter-component calls. It is neutral with respect to parallelism, allowing components to use whatever means they desire to communicate within their parallel ''cohort.'' We will discuss in detail the importance of performance in the design of the CCA and will analyze the performance costs associated with features of the CCA.

  11. Performance measurement and modeling of component applications in a high performance computing environment : a case study.

    SciTech Connect

    Armstrong, Robert C.; Ray, Jaideep; Malony, A.; Shende, Sameer; Trebon, Nicholas D.

    2003-11-01

    We present a case study of performance measurement and modeling of a CCA (Common Component Architecture) component-based application in a high performance computing environment. We explore issues peculiar to component-based HPC applications and propose a performance measurement infrastructure for HPC based loosely on recent work done for Grid environments. A prototypical implementation of the infrastructure is used to collect data for a three components in a scientific application and construct performance models for two of them. Both computational and message-passing performance are addressed.

  12. WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code

    NASA Astrophysics Data System (ADS)

    Mendygral, P. J.; Radcliffe, N.; Kandalla, K.; Porter, D.; O’Neill, B. J.; Nolting, C.; Edmon, P.; Donnert, J. M. F.; Jones, T. W.

    2017-02-01

    We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it may be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.

  13. A Component Architecture for High-Performance Scientific Computing

    SciTech Connect

    Bernholdt, D E; Allan, B A; Armstrong, R; Bertrand, F; Chiu, K; Dahlgren, T L; Damevski, K; Elwasif, W R; Epperly, T W; Govindaraju, M; Katz, D S; Kohl, J A; Krishnan, M; Kumfert, G; Larson, J W; Lefantzi, S; Lewis, M J; Malony, A D; McInnes, L C; Nieplocha, J; Norris, B; Parker, S G; Ray, J; Shende, S; Windus, T L; Zhou, S

    2004-12-14

    The Common Component Architecture (CCA) provides a means for software developers to manage the complexity of large-scale scientific simulations and to move toward a plug-and-play environment for high-performance computing. In the scientific computing context, component models also promote collaboration using independently developed software, thereby allowing particular individuals or groups to focus on the aspects of greatest interest to them. The CCA supports parallel and distributed computing as well as local high-performance connections between components in a language-independent manner. The design places minimal requirements on components and thus facilitates the integration of existing code into the CCA environment. The CCA model imposes minimal overhead to minimize the impact on application performance. The focus on high performance distinguishes the CCA from most other component models. The CCA is being applied within an increasing range of disciplines, including combustion research, global climate simulation, and computational chemistry.

  14. A Component Architecture for High-Performance Scientific Computing

    SciTech Connect

    Bernholdt, David E; Allan, Benjamin A; Armstrong, Robert C; Bertrand, Felipe; Chiu, Kenneth; Dahlgren, Tamara L; Damevski, Kostadin; Elwasif, Wael R; Epperly, Thomas G; Govindaraju, Madhusudhan; Katz, Daniel S; Kohl, James A; Krishnan, Manoj Kumar; Kumfert, Gary K; Larson, J Walter; Lefantzi, Sophia; Lewis, Michael J; Malony, Allen D; McInnes, Lois C; Nieplocha, Jarek; Norris, Boyana; Parker, Steven G; Ray, Jaideep; Shende, Sameer; Windus, Theresa L; Zhou, Shujia

    2006-07-03

    The Common Component Architecture (CCA) provides a means for software developers to manage the complexity of large-scale scientific simulations and to move toward a plug-and-play environment for high-performance computing. In the scientific computing context, component models also promote collaboration using independently developed software, thereby allowing particular individuals or groups to focus on the aspects of greatest interest to them. The CCA supports parallel and distributed computing as well as local high-performance connections between components in a language-independent manner. The design places minimal requirements on components and thus facilitates the integration of existing code into the CCA environment. The CCA model imposes minimal overhead to minimize the impact on application performance. The focus on high performance distinguishes the CCA from most other component models. The CCA is being applied within an increasing range of disciplines, including combustion research, global climate simulation, and computational chemistry.

  15. Ideation High Performers: A Study of Motivational Factors

    ERIC Educational Resources Information Center

    Bergendahl, Magnus; Magnusson, Mats; Björk, Jennie

    2015-01-01

    As innovation today is one of the keys to success for firms, creativity among employees becomes an important asset and the understanding about what motivates employees in ideation is consequently of high interest. This article addresses differences in motivation among high and low performers in ideation and contributes to existing theory by…

  16. Replicating High-Performing Public Schools: Lessons from the Field

    ERIC Educational Resources Information Center

    Wicoff, Kimberly; Howard, Don; Huggett, Jon

    2006-01-01

    The fact that far too many students leave high school unprepared to become contributing members of society is hardly news. What is news is the growing number of schools that are proving public education can work for every student. Unlike a decade ago, when it was hard to find more than a handful of high-performing public schools, today many such…

  17. Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

    NASA Astrophysics Data System (ADS)

    Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

    2014-10-01

    Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g-1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

  18. Stretchable and high-performance supercapacitors with crumpled graphene papers.

    PubMed

    Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

    2014-10-01

    Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g(-1)), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

  19. High performance surface-emitting lasers with dry etched facets

    NASA Astrophysics Data System (ADS)

    Ou, S. S.; Jansen, M.; Yang, J. J.; Sergant, M.; Mawst, L. J.; Botez, D.; Roth, T. J.; Hess, C.; Tu, C.

    1992-12-01

    The fabrication, performance characteristics, and applications of monolithic in-plane surface-emitting lasers (IPSELs) with dry-etched 45-degree micromirrors are reviewed. Several types of such laser diode structures in both junction-up and junction-down configurations are considered. The performance goals for IPSELs with 45-degree micromirrors are high power and efficiency, high duty cycle and CW operation, good reliability, and high fabrication yields. The proposed approach for achieving these goals includes uniform quantum well material growth and dry etching of the laser micromirrors with tight fabrication tolerances.

  20. Advances in Experiment Design for High Performance Aircraft

    NASA Technical Reports Server (NTRS)

    Morelli, Engene A.

    1998-01-01

    A general overview and summary of recent advances in experiment design for high performance aircraft is presented, along with results from flight tests. General theoretical background is included, with some discussion of various approaches to maneuver design. Flight test examples from the F-18 High Alpha Research Vehicle (HARV) are used to illustrate applications of the theory. Input forms are compared using Cramer-Rao bounds for the standard errors of estimated model parameters. Directions for future research in experiment design for high performance aircraft are identified.

  1. Modelling and design of high performance indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Rhoads, Sandra L.; Barnett, Allen M.

    1989-01-01

    A first principles pn junction device model has predicted new designs for high voltage, high efficiency InP solar cells. Measured InP material properties were applied and device parameters (thicknesses and doping) were adjusted to obtain optimal performance designs. Results indicate that p/n InP designs will provide higher voltages and higher energy conversion efficiencies than n/p structures. Improvements to n/p structures for increased efficiency are predicted. These new designs exploit the high absorption capabilities, relatively long diffusion lengths, and modest surface recombination velocities characteristic of InP. Predictions of performance indicate achievable open-circuit voltage values as high as 943 mV for InP and a practical maximum AM0 efficiency of 22.5 percent at 1 sun and 27 C. The details of the model, the optimal InP structure and the effect of individual parameter variations on device performance are presented.

  2. Combining Security Assurance and High Performance in Hostile Environments

    DTIC Science & Technology

    2010-11-01

    tested under most standard evaluation criteria. A very high level of security assurance is targeted, hence high attack potentials are assumed as per the...handling problems. Testing has proven reasonable bandwidth could be attained with mainstream hardware and software with Combining Security Assurance and...on software packet handling frameworks led to the testing and development of in-house solutions to perform highly-efficient packet en- capsulation and

  3. Life-cycle costs of high-performance cells

    NASA Technical Reports Server (NTRS)

    Daniel, R.; Burger, D.; Reiter, L.

    1985-01-01

    A life cycle cost analysis of high efficiency cells was presented. Although high efficiency cells produce more power, they also cost more to make and are more susceptible to array hot-spot heating. Three different computer analysis programs were used: SAMICS (solar array manufacturing industry costing standards), PVARRAY (an array failure mode/degradation simulator), and LCP (lifetime cost and performance). The high efficiency cell modules were found to be more economical in this study, but parallel redundancy is recommended.

  4. Unlocking the Black Box: Exploring the Link between High-Performance Work Systems and Performance

    ERIC Educational Resources Information Center

    Messersmith, Jake G.; Patel, Pankaj C.; Lepak, David P.

    2011-01-01

    With a growing body of literature linking systems of high-performance work practices to organizational performance outcomes, recent research has pushed for examinations of the underlying mechanisms that enable this connection. In this study, based on a large sample of Welsh public-sector employees, we explored the role of several individual-level…

  5. Optical interconnection networks for high-performance computing systems.

    PubMed

    Biberman, Aleksandr; Bergman, Keren

    2012-04-01

    Enabled by silicon photonic technology, optical interconnection networks have the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. Chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, offer unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of our work, we demonstrate such feasibility of waveguides, modulators, switches and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. We propose novel silicon photonic devices, subsystems, network topologies and architectures to enable unprecedented performance of these photonic interconnection networks. Furthermore, the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers.

  6. TMD-Based Structural Control of High Performance Steel Bridges

    NASA Astrophysics Data System (ADS)

    Kim, Tae Min; Kim, Gun; Kyum Kim, Moon

    2012-08-01

    The purpose of this study is to investigate the effectiveness of structural control using tuned mass damper (TMD) for suppressing excessive traffic induced vibration of high performance steel bridge. The study considered 1-span steel plate girder bridge and bridge-vehicle interaction using HS-24 truck model. A numerical model of steel plate girder, traffic load, and TMD is constructed and time history analysis is performed using commercial structural analysis program ABAQUS 6.10. Results from analyses show that high performance steel bridge has dynamic serviceability problem, compared to relatively low performance steel bridge. Therefore, the structural control using TMD is implemented in order to alleviate dynamic serviceability problems. TMD is applied to the bridge with high performance steel and then vertical vibration due to dynamic behavior is assessed again. In consequent, by using TMD, it is confirmed that the residual amplitude is appreciably reduced by 85% in steady-state vibration. Moreover, vibration serviceability assessment using 'Reiher-Meister Curve' is also remarkably improved. As a result, this paper provides the guideline for economical design of I-girder using high performance steel and evaluates the effectiveness of structural control using TMD, simultaneously.

  7. Resource estimation in high performance medical image computing.

    PubMed

    Banalagay, Rueben; Covington, Kelsie Jade; Wilkes, D M; Landman, Bennett A

    2014-10-01

    Medical imaging analysis processes often involve the concatenation of many steps (e.g., multi-stage scripts) to integrate and realize advancements from image acquisition, image processing, and computational analysis. With the dramatic increase in data size for medical imaging studies (e.g., improved resolution, higher throughput acquisition, shared databases), interesting study designs are becoming intractable or impractical on individual workstations and servers. Modern pipeline environments provide control structures to distribute computational load in high performance computing (HPC) environments. However, high performance computing environments are often shared resources, and scheduling computation across these resources necessitates higher level modeling of resource utilization. Submission of 'jobs' requires an estimate of the CPU runtime and memory usage. The resource requirements for medical image processing algorithms are difficult to predict since the requirements can vary greatly between different machines, different execution instances, and different data inputs. Poor resource estimates can lead to wasted resources in high performance environments due to incomplete executions and extended queue wait times. Hence, resource estimation is becoming a major hurdle for medical image processing algorithms to efficiently leverage high performance computing environments. Herein, we present our implementation of a resource estimation system to overcome these difficulties and ultimately provide users with the ability to more efficiently utilize high performance computing resources.

  8. A grid computing framework for high-performance medical imaging

    NASA Astrophysics Data System (ADS)

    Mañana Guichón, Gabriel; Romero Castro, Eduardo

    2013-11-01

    Current medical image processing has become a complex mixture of many scienti c disciplines including mathematics, statistics, physics, and algorithmics, to perform tasks such as registration, segmentation, and visualization, with the ultimate purpose of helping clinicians in their daily routine. This requires high performance computing capabilities that can be achieved in several ways, usually una ordable for most medical institutions. This paper presents a space-based computational grid that uses the otherwise wasted CPU cycles of a set of personal computers, to provide high-performance medical imaging services over the Internet. By using an existing hardware infrastructure and software of free distribution, the proposed approach is apt for university hospitals and other low-budget institutions. This will be illustrated by the use of three real case studies of services where an important speedup factor has been obtained and whose performance has become suitable for use in real clinical scenarios.

  9. Some design considerations for high-performance infrared imaging seeker

    NASA Astrophysics Data System (ADS)

    Fan, Jinxiang; Huang, Jianxiong

    2015-10-01

    In recent years, precision guided weapons play more and more important role in modern war. The development and applications of infrared imaging guidance technology have been paid more and more attention. And with the increasing of the complexity of mission and environment, precision guided weapons make stricter demand for infrared imaging seeker. The demands for infrared imaging seeker include: high detection sensitivity, large dynamic range, having better target recognition capability, having better anti-jamming capability and better environment adaptability. To meet the strict demand of weapon system, several important issues should be considered in high-performance infrared imaging seeker design. The mission, targets, environment of infrared imaging guided missile must be regarded. The tradeoff among performance goal, design parameters, infrared technology constraints and missile constraints should be considered. The optimized application of IRFPA and ATR in complicated environment should be concerned. In this paper, some design considerations for high-performance infrared imaging seeker were discussed.

  10. The Process Guidelines for High-Performance Buildings

    SciTech Connect

    Grondzik, W.

    1999-07-01

    The Process Guidelines for High-Performance Buildings are a set of recommendations for the design and operation of efficient and effective commercial/institutional buildings. The Process Guidelines have been developed in a searchable database format and are intended to replace print documents that provide guidance for new building designs for the State of Florida and for the operation of existing State buildings. The Process Guidelines for High-Performance buildings reside on the World Wide Web and are publicly accessible. Contents may be accessed in a variety of ways to best suit the needs of the user. The Process Guidelines address the interests of a range of facilities professionals; are organized around the primary phases of building design, construction, and operation; and include content dealing with all major building systems. The Process Guidelines for High-Performance Buildings may be accessed through the ``Resources'' area of the edesign Web site: http://fcn.state.fl.us/fdi/edesign/resource/index.html.

  11. SIMS analysis of high-performance accelerator niobium

    SciTech Connect

    Maheshwari, P.; Stevie, F. A.; Myneni, Ganapati Rao; Rigsbee, J, M.; Dhakal, Pashupati; Ciovati, Gianluigi; Griffis, D. P.

    2014-11-01

    Niobium is used to fabricate superconducting radio frequency accelerator modules because of its high critical temperature, high critical magnetic field, and easy formability. Recent experiments have shown a very significant improvement in performance (over 100%) after a high-temperature bake at 1400 degrees C for 3h. SIMS analysis of this material showed the oxygen profile was significantly deeper than the native oxide with a shape that is indicative of diffusion. Positive secondary ion mass spectra showed the presence of Ti with a depth profile similar to that of O. It is suspected that Ti is associated with the performance improvement. The source of Ti contamination in the anneal furnace has been identified, and a new furnace was constructed without Ti. Initial results from the new furnace do not show the yield improvement. Further analyses should determine the relationship of Ti to cavity performance.

  12. High voltage stability performance of a gamma ray detection device

    NASA Astrophysics Data System (ADS)

    Abdullah, Nor Arymaswati; Lombigit, Lojius; Rahman, Nur Aira Abd

    2014-02-01

    An industrial grade digital radiation survey meter device is currently being developed at Malaysian Nuclear Agency. This device used a cylindrical type Geiger Mueller (GM) which acts as a detector. GM detector operates at relatively high direct current voltages depend on the type of GM tube. This thin/thick walled cylindrical type of GM tube operates at 450-650 volts range. Proper value and stability performance of high voltage are important parameters to ensure that this device give a reliable radiation dose measurement. This paper will present an assessment of the stability and performance of the high voltage supply for radiation detector. The assessment is performed using System Identification tools box in MATLAB and mathematical statistics.

  13. High voltage stability performance of a gamma ray detection device

    SciTech Connect

    Abdullah, Nor Arymaswati; Lombigit, Lojius; Rahman, Nur Aira Abd

    2014-02-12

    An industrial grade digital radiation survey meter device is currently being developed at Malaysian Nuclear Agency. This device used a cylindrical type Geiger Mueller (GM) which acts as a detector. GM detector operates at relatively high direct current voltages depend on the type of GM tube. This thin/thick walled cylindrical type of GM tube operates at 450-650 volts range. Proper value and stability performance of high voltage are important parameters to ensure that this device give a reliable radiation dose measurement. This paper will present an assessment of the stability and performance of the high voltage supply for radiation detector. The assessment is performed using System Identification tools box in MATLAB and mathematical statistics.

  14. High performance APCS conceptual design and evaluation scoping study

    SciTech Connect

    Soelberg, N.; Liekhus, K.; Chambers, A.; Anderson, G.

    1998-02-01

    This Air Pollution Control System (APCS) Conceptual Design and Evaluation study was conducted to evaluate a high-performance (APC) system for minimizing air emissions from mixed waste thermal treatment systems. Seven variations of high-performance APCS designs were conceptualized using several design objectives. One of the system designs was selected for detailed process simulation using ASPEN PLUS to determine material and energy balances and evaluate performance. Installed system capital costs were also estimated. Sensitivity studies were conducted to evaluate the incremental cost and benefit of added carbon adsorber beds for mercury control, specific catalytic reduction for NO{sub x} control, and offgas retention tanks for holding the offgas until sample analysis is conducted to verify that the offgas meets emission limits. Results show that the high-performance dry-wet APCS can easily meet all expected emission limits except for possibly mercury. The capability to achieve high levels of mercury control (potentially necessary for thermally treating some DOE mixed streams) could not be validated using current performance data for mercury control technologies. The engineering approach and ASPEN PLUS modeling tool developed and used in this study identified APC equipment and system performance, size, cost, and other issues that are not yet resolved. These issues need to be addressed in feasibility studies and conceptual designs for new facilities or for determining how to modify existing facilities to meet expected emission limits. The ASPEN PLUS process simulation with current and refined input assumptions and calculations can be used to provide system performance information for decision-making, identifying best options, estimating costs, reducing the potential for emission violations, providing information needed for waste flow analysis, incorporating new APCS technologies in existing designs, or performing facility design and permitting activities.

  15. High Performance Remote Memory Access Communication: The ARMCI Approach

    SciTech Connect

    Nieplocha, Jarek; Tipparaju, Vinod; Krishnan, Manoj Kumar; Panda, Dhabaleswar K.

    2006-07-01

    This paper describes the Aggregate Remote Memory Copy Interface (ARMCI), a portable high performance remote memory access (RMA) communication interface, developed originally under the DoE-2000 ACTS Toolkit project and currently used as a part of the run-time layer of the DoE project Programming Models for Scalable Parallel Computing. The paper discusses the model, portable implementation, and performance of ARMCI. Special emphasis is placed on the latency hiding mechanisms and ability to optimize noncontiguous data transfers.

  16. Achieving High Performance on the i860 Microprocessor

    NASA Technical Reports Server (NTRS)

    Lee, King; Kutler, Paul (Technical Monitor)

    1998-01-01

    The i860 is a high performance microprocessor used in the Intel Touchstone project. This paper proposes a paradigm for programming the i860 that is modelled on the vector instructions of the Cray computers. Fortran callable assembler subroutines were written that mimic the concurrent vector instructions of the Cray. Cache takes the place of vector registers. Using this paradigm we have achieved twice the performance of compiled code on a traditional solve.

  17. Expanding the Scope of High-Performance Computing Facilities

    SciTech Connect

    Uram, Thomas D.; Papka, Michael E.

    2016-05-01

    The high-performance computing centers of the future will expand their roles as service providers, and as the machines scale up, so should the sizes of the communities they serve. National facilities must cultivate their users as much as they focus on operating machines reliably. The authors present five interrelated topic areas that are essential to expanding the value provided to those performing computational science.

  18. Unlocking the black box: exploring the link between high-performance work systems and performance.

    PubMed

    Messersmith, Jake G; Patel, Pankaj C; Lepak, David P; Gould-Williams, Julian

    2011-11-01

    With a growing body of literature linking systems of high-performance work practices to organizational performance outcomes, recent research has pushed for examinations of the underlying mechanisms that enable this connection. In this study, based on a large sample of Welsh public-sector employees, we explored the role of several individual-level attitudinal factors--job satisfaction, organizational commitment, and psychological empowerment--as well as organizational citizenship behaviors that have the potential to provide insights into how human resource systems influence the performance of organizational units. The results support a unit-level path model, such that department-level, high-performance work system utilization is associated with enhanced levels of job satisfaction, organizational commitment, and psychological empowerment. In turn, these attitudinal variables were found to be positively linked to enhanced organizational citizenship behaviors, which are further related to a second-order construct measuring departmental performance.

  19. Optimum selection of high performance mirror substrates for diamond finishing

    NASA Astrophysics Data System (ADS)

    Woodard, Kenneth S.; Comstock, Lovell E.; Wamboldt, Leonard; Sutherland, James S.

    2016-05-01

    Due to advances in manufacturing processes, the substrate options for high performance diamond machined mirrors are expanding. Fewer compromises have to be made to achieve the needed weight, stiffness and finish while maintaining reasonable costs. In addition to the traditional mirror materials like aluminum and beryllium, there are some less common materials that can now be included in the trade space that fill the cost and performance continuum between wrought aluminum and beryllium mirrors. Aluminum and beryllium, respectively, had been the low cost/fair performance and very high cost/very high performance bounds for substrate selection. These additional substrates provide multiple near net shape blank options and processes, mostly within these bounds, that can be considered in a mirror cost versus performance trade analysis. This paper will include a summary of some advances in manufacturing processes that provide more substrate options for diamond machined mirrors with some sample performance analysis and data. This is merged with the traditional substrate options to illustrate the now larger mirror substrate trade space. Some benchmark structural analysis is provided to back up a generic mirror design trade study.

  20. CVC silicon carbide high-performance optical systems

    NASA Astrophysics Data System (ADS)

    Fischer, William F., III; Foss, Colby A., Jr.

    2004-10-01

    The demand for high performance lightweight mirrors has never been greater. The coming years will require lighter and higher performance mirrors and in greater numbers than is currently available. Applications include both ground and space based telescopes, surveillance, navigation, guidance, and tracking and control systems. For instance, the total requirement for US government sponsored systems alone is projected to be greater than 200 m2/year1. Given that the total current global production capacity is on the order of 50 m2/year1, the need and opportunity to rapidly produce high quality optics is readily apparent. Key areas of concern for all these programs are not only the mission critical optical performance metrics, but also the ability to meet the timeline for deployment. As such, any potential reduction in the long lead times for manufactured optical systems and components is critical. The associated improvements with such advancements would lead to reductions in schedule and acquisition cost, as well as increased performance. Trex"s patented CVC SiC process is capable of rapidly producing high performance SiC optics for any optical system. This paper will summarize the CVC SiC production process and the current optical performance levels, as well as future areas of work.

  1. High Performance Walls in Hot-Dry Climates

    SciTech Connect

    Hoeschele, Marc; Springer, David; Dakin, Bill; German, Alea

    2015-01-01

    High performance walls represent a high priority measure for moving the next generation of new homes to the Zero Net Energy performance level. The primary goal in improving wall thermal performance revolves around increasing the wall framing from 2x4 to 2x6, adding more cavity and exterior rigid insulation, achieving insulation installation criteria meeting ENERGY STAR's thermal bypass checklist. To support this activity, in 2013 the Pacific Gas & Electric Company initiated a project with Davis Energy Group (lead for the Building America team, Alliance for Residential Building Innovation) to solicit builder involvement in California to participate in field demonstrations of high performance wall systems. Builders were given incentives and design support in exchange for providing site access for construction observation, cost information, and builder survey feedback. Information from the project was designed to feed into the 2016 Title 24 process, but also to serve as an initial mechanism to engage builders in more high performance construction strategies. This Building America project utilized information collected in the California project.

  2. Cray XMT Brings New Energy to High-Performance Computing

    SciTech Connect

    Chavarría-Miranda, Daniel; Gracio, Deborah K.; Marquez, Andres; Nieplocha, Jaroslaw; Scherrer, Chad; Sofia, Heidi J.

    2008-09-30

    The ability to solve our nation’s most challenging problems—whether it’s cleaning up the environment, finding alternative forms of energy or improving public health and safety—requires new scientific discoveries. High performance experimental and computational technologies from the past decade are helping to accelerate these scientific discoveries, but they introduce challenges of their own. The vastly increasing volumes and complexities of experimental and computational data pose significant challenges to traditional high-performance computing (HPC) platforms as terabytes to petabytes of data must be processed and analyzed. And the growing complexity of computer models that incorporate dynamic multiscale and multiphysics phenomena place enormous demands on high-performance computer architectures. Just as these new challenges are arising, the computer architecture world is experiencing a renaissance of innovation. The continuing march of Moore’s law has provided the opportunity to put more functionality on a chip, enabling the achievement of performance in new ways. Power limitations, however, will severely limit future growth in clock rates. The challenge will be to obtain greater utilization via some form of on-chip parallelism, but the complexities of emerging applications will require significant innovation in high-performance architectures. The Cray XMT, the successor to the Tera/Cray MTA, provides an alternative platform for addressing computations that stymie current HPC systems, holding the potential to substantially accelerate data analysis and predictive analytics for many complex challenges in energy, national security and fundamental science that traditional computing cannot do.

  3. High-performance silicon photonics technology for telecommunications applications.

    PubMed

    Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

    2014-04-01

    By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge-based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge-based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications.

  4. High Performance Flat Plate Solar Thermal Collector Evaluation

    SciTech Connect

    Rockenbaugh, Caleb; Dean, Jesse; Lovullo, David; Lisell, Lars; Barker, Greg; Hanckock, Ed; Norton, Paul

    2016-09-01

    This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.

  5. Comparative performance of wavelets and JPEG coders at high quality

    NASA Astrophysics Data System (ADS)

    Algazi, V. Ralph; Estes, Robert R., Jr.

    1997-04-01

    In recent work, we have examined the performance of wavelet coders using a perceptually relevant image quality metric, the picture quality scale (PQS). In that study, we considered some of the design options available with respect to choice of wavelet basis, quantizer, and method for error- free encoding of the quantized coefficients, including the EZW methodology. A specific combination of these design options provides the best trade off between performance and PQS quality. Here, we extend this comparison by evaluating the performance of JPEG and the previously chosen optimal wavelet scheme, focusing principally on the high quality range.

  6. High performance computing and communications: FY 1997 implementation plan

    SciTech Connect

    1996-12-01

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage, with bipartisan support, of the High-Performance Computing Act of 1991, signed on December 9, 1991. The original Program, in which eight Federal agencies participated, has now grown to twelve agencies. This Plan provides a detailed description of the agencies` FY 1996 HPCC accomplishments and FY 1997 HPCC plans. Section 3 of this Plan provides an overview of the HPCC Program. Section 4 contains more detailed definitions of the Program Component Areas, with an emphasis on the overall directions and milestones planned for each PCA. Appendix A provides a detailed look at HPCC Program activities within each agency.

  7. Visualization and Data Analysis for High-Performance Computing

    SciTech Connect

    Sewell, Christopher Meyer

    2016-09-27

    This is a set of slides from a guest lecture for a class at the University of Texas, El Paso on visualization and data analysis for high-performance computing. The topics covered are the following: trends in high-performance computing; scientific visualization, such as OpenGL, ray tracing and volume rendering, VTK, and ParaView; data science at scale, such as in-situ visualization, image databases, distributed memory parallelism, shared memory parallelism, VTK-m, "big data", and then an analysis example.

  8. GPU-based High-Performance Computing for Radiation Therapy

    PubMed Central

    Jia, Xun; Ziegenhein, Peter; Jiang, Steve B.

    2014-01-01

    Recent developments in radiotherapy therapy demand high computation powers to solve challenging problems in a timely fashion in a clinical environment. Graphics processing unit (GPU), as an emerging high-performance computing platform, has been introduced to radiotherapy. It is particularly attractive due to its high computational power, small size, and low cost for facility deployment and maintenance. Over the past a few years, GPU-based high-performance computing in radiotherapy has experienced rapid developments. A tremendous amount of studies have been conducted, in which large acceleration factors compared with the conventional CPU platform have been observed. In this article, we will first give a brief introduction to the GPU hardware structure and programming model. We will then review the current applications of GPU in major imaging-related and therapy-related problems encountered in radiotherapy. A comparison of GPU with other platforms will also be presented. PMID:24486639

  9. GPU-based high-performance computing for radiation therapy.

    PubMed

    Jia, Xun; Ziegenhein, Peter; Jiang, Steve B

    2014-02-21

    Recent developments in radiotherapy therapy demand high computation powers to solve challenging problems in a timely fashion in a clinical environment. The graphics processing unit (GPU), as an emerging high-performance computing platform, has been introduced to radiotherapy. It is particularly attractive due to its high computational power, small size, and low cost for facility deployment and maintenance. Over the past few years, GPU-based high-performance computing in radiotherapy has experienced rapid developments. A tremendous amount of study has been conducted, in which large acceleration factors compared with the conventional CPU platform have been observed. In this paper, we will first give a brief introduction to the GPU hardware structure and programming model. We will then review the current applications of GPU in major imaging-related and therapy-related problems encountered in radiotherapy. A comparison of GPU with other platforms will also be presented.

  10. Tellurium as a high-performance elemental thermoelectric

    PubMed Central

    Lin, Siqi; Li, Wen; Chen, Zhiwei; Shen, Jiawen; Ge, Binghui; Pei, Yanzhong

    2016-01-01

    High-efficiency thermoelectric materials require a high conductivity. It is known that a large number of degenerate band valleys offers many conducting channels for improving the conductivity without detrimental effects on the other properties explicitly, and therefore, increases thermoelectric performance. In addition to the strategy of converging different bands, many semiconductors provide an inherent band nestification, equally enabling a large number of effective band valley degeneracy. Here we show as an example that a simple elemental semiconductor, tellurium, exhibits a high thermoelectric figure of merit of unity, not only demonstrating the concept but also filling up the high performance gap from 300 to 700 K for elemental thermoelectrics. The concept used here should be applicable in general for thermoelectrics with similar band features. PMID:26751919

  11. Tellurium as a high-performance elemental thermoelectric.

    PubMed

    Lin, Siqi; Li, Wen; Chen, Zhiwei; Shen, Jiawen; Ge, Binghui; Pei, Yanzhong

    2016-01-11

    High-efficiency thermoelectric materials require a high conductivity. It is known that a large number of degenerate band valleys offers many conducting channels for improving the conductivity without detrimental effects on the other properties explicitly, and therefore, increases thermoelectric performance. In addition to the strategy of converging different bands, many semiconductors provide an inherent band nestification, equally enabling a large number of effective band valley degeneracy. Here we show as an example that a simple elemental semiconductor, tellurium, exhibits a high thermoelectric figure of merit of unity, not only demonstrating the concept but also filling up the high performance gap from 300 to 700 K for elemental thermoelectrics. The concept used here should be applicable in general for thermoelectrics with similar band features.

  12. Stability and control of maneuvering high-performance aircraft

    NASA Technical Reports Server (NTRS)

    Stengel, R. F.; Berry, P. W.

    1977-01-01

    The stability and control of a high-performance aircraft was analyzed, and a design methodology for a departure prevention stability augmentation system (DPSAS) was developed. A general linear aircraft model was derived which includes maneuvering flight effects and trim calculation procedures for investigating highly dynamic trajectories. The stability and control analysis systematically explored the effects of flight condition and angular motion, as well as the stability of typical air combat trajectories. The effects of configuration variation also were examined.

  13. Development of a Plastic Rotating Band for High Performance Projectiles

    DTIC Science & Technology

    1974-07-01

    thus: An optimum high explosive projectile design requires a thin , uniform wall which assures a distribution of nearly constant size fragments. Thus...relatively low charge-to-mass ratio and a skewed frag- ment size distribution. The problem of attaching a plastic band to a thin - walled , high perform...40 4 Dexon XPA-3 Formulations with Glass Fibers. .*. . 70 5 Properties of Nylafil/ Foam F-3/15 . . . . . . . 72 6 Property Comparison for Nylon

  14. Automated Fabrication Technologies for High Performance Polymer Composites

    NASA Technical Reports Server (NTRS)

    Shuart , M. J.; Johnston, N. J.; Dexter, H. B.; Marchello, J. M.; Grenoble, R. W.

    1998-01-01

    New fabrication technologies are being exploited for building high graphite-fiber-reinforced composite structure. Stitched fiber preforms and resin film infusion have been successfully demonstrated for large, composite wing structures. Other automatic processes being developed include automated placement of tacky, drapable epoxy towpreg, automated heated head placement of consolidated ribbon/tape, and vacuum-assisted resin transfer molding. These methods have the potential to yield low cost high performance structures by fabricating composite structures to net shape out-of-autoclave.

  15. Beating the Odds: High Performing, Small High-Schools in the Rural South

    ERIC Educational Resources Information Center

    Rural School and Community Trust, 2004

    2004-01-01

    The Southern Rural High School Study Initiative seeks to identify high performing rural high schools in the South, engage education leaders in the region in analyzing the challenges faced by these schools and consider the public policies that might serve to transfer the lessons and strategies used by these schools to other small rural high schools…

  16. High-performance mass storage system for workstations

    NASA Technical Reports Server (NTRS)

    Chiang, T.; Tang, Y.; Gupta, L.; Cooperman, S.

    1993-01-01

    Reduced Instruction Set Computer (RISC) workstations and Personnel Computers (PC) are very popular tools for office automation, command and control, scientific analysis, database management, and many other applications. However, when using Input/Output (I/O) intensive applications, the RISC workstations and PC's are often overburdened with the tasks of collecting, staging, storing, and distributing data. Also, by using standard high-performance peripherals and storage devices, the I/O function can still be a common bottleneck process. Therefore, the high-performance mass storage system, developed by Loral AeroSys' Independent Research and Development (IR&D) engineers, can offload a RISC workstation of I/O related functions and provide high-performance I/O functions and external interfaces. The high-performance mass storage system has the capabilities to ingest high-speed real-time data, perform signal or image processing, and stage, archive, and distribute the data. This mass storage system uses a hierarchical storage structure, thus reducing the total data storage cost, while maintaining high-I/O performance. The high-performance mass storage system is a network of low-cost parallel processors and storage devices. The nodes in the network have special I/O functions such as: SCSI controller, Ethernet controller, gateway controller, RS232 controller, IEEE488 controller, and digital/analog converter. The nodes are interconnected through high-speed direct memory access links to form a network. The topology of the network is easily reconfigurable to maximize system throughput for various applications. This high-performance mass storage system takes advantage of a 'busless' architecture for maximum expandability. The mass storage system consists of magnetic disks, a WORM optical disk jukebox, and an 8mm helical scan tape to form a hierarchical storage structure. Commonly used files are kept in the magnetic disk for fast retrieval. The optical disks are used as archive

  17. Combining high performance simulation, data acquisition, and graphics display computers

    NASA Technical Reports Server (NTRS)

    Hickman, Robert J.

    1989-01-01

    Issues involved in the continuing development of an advanced simulation complex are discussed. This approach provides the capability to perform the majority of tests on advanced systems, non-destructively. The controlled test environments can be replicated to examine the response of the systems under test to alternative treatments of the system control design, or test the function and qualification of specific hardware. Field tests verify that the elements simulated in the laboratories are sufficient. The digital computer is hosted by a Digital Equipment Corp. MicroVAX computer with an Aptec Computer Systems Model 24 I/O computer performing the communication function. An Applied Dynamics International AD100 performs the high speed simulation computing and an Evans and Sutherland PS350 performs on-line graphics display. A Scientific Computer Systems SCS40 acts as a high performance FORTRAN program processor to support the complex, by generating numerous large files from programs coded in FORTRAN that are required for the real time processing. Four programming languages are involved in the process, FORTRAN, ADSIM, ADRIO, and STAPLE. FORTRAN is employed on the MicroVAX host to initialize and terminate the simulation runs on the system. The generation of the data files on the SCS40 also is performed with FORTRAN programs. ADSIM and ADIRO are used to program the processing elements of the AD100 and its IOCP processor. STAPLE is used to program the Aptec DIP and DIA processors.

  18. 24 CFR 902.71 - Incentives for high performers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Incentives for high performers. 902.71 Section 902.71 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND...

  19. Seeking Solution: High-Performance Computing for Science. Background Paper.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Office of Technology Assessment.

    This is the second publication from the Office of Technology Assessment's assessment on information technology and research, which was requested by the House Committee on Science and Technology and the Senate Committee on Commerce, Science, and Transportation. The first background paper, "High Performance Computing & Networking for…

  20. Planning and Implementing a High Performance Knowledge Base.

    ERIC Educational Resources Information Center

    Cortez, Edwin M.

    1999-01-01

    Discusses the conceptual framework for developing a rapid-prototype high-performance knowledge base for the four mission agencies of the United States Department of Agriculture and their university partners. Describes the background of the project and methods used for establishing the requirements; examines issues and problems surrounding semantic…

  1. National Best Practices Manual for Building High Performance Schools

    ERIC Educational Resources Information Center

    US Department of Energy, 2007

    2007-01-01

    The U.S. Department of Energy's Rebuild America EnergySmart Schools program provides school boards, administrators, and design staff with guidance to help make informed decisions about energy and environmental issues important to school systems and communities. "The National Best Practices Manual for Building High Performance Schools" is a part of…

  2. The role of interpreters in high performance computing

    SciTech Connect

    Naumann, Axel; Canal, Philippe; /Fermilab

    2008-01-01

    Compiled code is fast, interpreted code is slow. There is not much we can do about it, and it's the reason why interpreters use in high performance computing is usually restricted to job submission. We show where interpreters make sense even in the context of analysis code, and what aspects have to be taken into account to make this combination a success.

  3. Recruiting, Training, and Retaining High-Performance Development Teams

    ERIC Educational Resources Information Center

    Elder, Stephen D.

    2010-01-01

    This chapter offers thoughts on some key elements of a high-performing development environment. The author describes how good development officers love to be part of something big, something that transforms a place and its people, and that thinking big is a powerful concept for development officers. He reminds development officers to be clear…

  4. Multichannel Detection in High-Performance Liquid Chromatography.

    ERIC Educational Resources Information Center

    Miller, James C.; And Others

    1982-01-01

    A linear photodiode array is used as the photodetector element in a new ultraviolet-visible detection system for high-performance liquid chromatography (HPLC). Using a computer network, the system processes eight different chromatographic signals simultaneously in real-time and acquires spectra manually/automatically. Applications in fast HPLC…

  5. Inside School Improvement: Creating High-Performing Learning Communities.

    ERIC Educational Resources Information Center

    Walsh, Jackie A.; Sattes, Beth D.

    In 1997, AEL, a regional educational laboratory, invited more than 100 people from 18 primarily rural school communities in Kentucky, Tennessee, Virginia, and West Virginia to join the QUEST network, a 3-year program dedicated to building quality learning communities that support high levels of student and adult performance. School stories from…

  6. High-Performance Liquid Chromatography-Mass Spectrometry.

    ERIC Educational Resources Information Center

    Vestal, Marvin L.

    1984-01-01

    Reviews techniques for online coupling of high-performance liquid chromatography with mass spectrometry, emphasizing those suitable for application to nonvolatile samples. Also summarizes the present status, strengths, and weaknesses of various techniques and discusses potential applications of recently developed techniques for combined liquid…

  7. The Influence of Social Networks on High School Students' Performance

    ERIC Educational Resources Information Center

    Abu-Shanab, Emad; Al-Tarawneh, Heyam

    2015-01-01

    Social networks are becoming an integral part of people's lives. Students are spending much time on social media and are considered the largest category that uses such application. This study tries to explore the influence of social media use, and especially Facebook, on high school students' performance. The study used the GPA of students in four…

  8. Understanding the Work and Learning of High Performance Coaches

    ERIC Educational Resources Information Center

    Rynne, Steven B.; Mallett, Cliff J.

    2012-01-01

    Background: The development of high performance sports coaches has been proposed as a major imperative in the professionalization of sports coaching. Accordingly, an increasing body of research is beginning to address the question of how coaches learn. While this is important work, an understanding of how coaches learn must be underpinned by an…

  9. Improving Math Performance in High Risk Schools: A Qualitative Study

    ERIC Educational Resources Information Center

    Pena, Leticia M.

    2013-01-01

    The researcher developed a case study using a qualitative research methodology to describe the functions of a team of math teachers in a professional learning community in a Title 1 low performing high school that led to increased student achievement. The tenth-grade Texas Assessment of Knowledge and Skills (TAKS) mathematics results for the…

  10. High School Grades and University Performance: A Case Study

    ERIC Educational Resources Information Center

    Cyrenne, Philippe; Chan, Alan

    2012-01-01

    A critical issue facing a number of colleges and universities is how to allocate first year places to incoming students. The decision to admit students is often based on a number of factors, but a key statistic is a student's high school grades. This paper reports on a case study of the subsequent performance at the University of Winnipeg of high…

  11. Student Achievement Data Systems in High and Low Performing Schools

    ERIC Educational Resources Information Center

    Stachowiak, Jeannie E.

    2013-01-01

    The purpose of this study was to determine if there was a difference in how high and low performing elementary school districts use and analyze data to differentiate instruction, make changes to district/grade level curriculum, determine professional development needs, determine teacher effectiveness, and determine the use of school district…

  12. The Case for High-Performance, Healthy Green Schools

    ERIC Educational Resources Information Center

    Carter, Leesa

    2011-01-01

    When trying to reach their sustainability goals, schools and school districts often run into obstacles, including financing, training, and implementation tools. Last fall, the U.S. Green Building Council-Georgia (USGBC-Georgia) launched its High Performance, Healthy Schools (HPHS) Program to help Georgia schools overcome those obstacles. By…

  13. Training Needs for High Performance in the Automotive Industry.

    ERIC Educational Resources Information Center

    Clyne, Barry; And Others

    A project was conducted in Australia to identify the training needs of the emerging industry required to support the development of the high performance areas of the automotive machining and reconditioning field especially as it pertained to auto racing. Data were gathered through a literature search, interviews with experts in the field, and…

  14. Quantification of Tea Flavonoids by High Performance Liquid Chromatography

    ERIC Educational Resources Information Center

    Freeman, Jessica D.; Niemeyer, Emily D.

    2008-01-01

    We have developed a laboratory experiment that uses high performance liquid chromatography (HPLC) to quantify flavonoid levels in a variety of commercial teas. Specifically, this experiment analyzes a group of flavonoids known as catechins, plant-derived polyphenolic compounds commonly found in many foods and beverages, including green and black…

  15. Efficient High Performance Collective Communication for Distributed Memory Environments

    ERIC Educational Resources Information Center

    Ali, Qasim

    2009-01-01

    Collective communication allows efficient communication and synchronization among a collection of processes, unlike point-to-point communication that only involves a pair of communicating processes. Achieving high performance for both kernels and full-scale applications running on a distributed memory system requires an efficient implementation of…

  16. Employee Retention and Performance Improvement in High-Tech Companies.

    ERIC Educational Resources Information Center

    Ware, B. Lynn

    2001-01-01

    Considers the benefits of employee retention and performance improvement in high technology, new economy companies. Discusses attracting and retaining top talent in information technology companies; targeted recruiting and hiring; employee achievement; learning and professional growth; recognition; nurturing careers; team collaboration; the TALENT…

  17. Mallow carotenoids determined by high-performance liquid chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mallow (corchorus olitorius) is a green vegetable, which is widely consumed either fresh or dry by Middle East population. This study was carried out to determine the contents of major carotenoids quantitatively in mallow, by using a High Performance Liquid Chromatography (HPLC) equipped with a Bis...

  18. Friction Stir Additive Manufacturing: Route to High Structural Performance

    NASA Astrophysics Data System (ADS)

    Palanivel, S.; Sidhar, H.; Mishra, R. S.

    2015-03-01

    Aerospace and automotive industries provide the next big opportunities for additive manufacturing. Currently, the additive industry is confronted with four major challenges that have been identified in this article. These challenges need to be addressed for the additive technologies to march into new frontiers and create additional markets. Specific potential success in the transportation sectors is dependent on the ability to manufacture complicated structures with high performance. Most of the techniques used for metal-based additive manufacturing are fusion based because of their ability to fulfill the computer-aided design to component vision. Although these techniques aid in fabrication of complex shapes, achieving high structural performance is a key problem due to the liquid-solid phase transformation. In this article, friction stir additive manufacturing (FSAM) is shown as a potential solid-state process for attaining high-performance lightweight alloys for simpler geometrical applications. To illustrate FSAM as a high-performance route, manufactured builds of Mg-4Y-3Nd and AA5083 are shown as examples. In the Mg-based alloy, an average hardness of 120 HV was achieved in the built structure and was significantly higher than that of the base material (97 HV). Similarly for the Al-based alloy, compared with the base hardness of 88 HV, the average built hardness was 104 HV. A potential application of FSAM is illustrated by taking an example of a simple stiffener assembly.

  19. Guide to School Design: Healthy + High Performance Schools

    ERIC Educational Resources Information Center

    Healthy Schools Network, Inc., 2007

    2007-01-01

    A "healthy and high performance school" uses a holistic design process to promote the health and comfort of children and school employees, as well as conserve resources. Children may spend over eight hours a day at school with little, if any, legal protection from environmental hazards. Schools are generally not well-maintained; asthma is a…

  20. Application of high-performance OEM fibre lasers in manufacturing

    NASA Astrophysics Data System (ADS)

    Norman, S.; Appleyard, A.; Harrison, P.; Hassey, A.

    2012-02-01

    Medium and high-power fiber lasers operating in the 1um region have proven their capabilities for cutting and welding in industrial manufacturing applications. This paper reviews the process performance capabilities of medium power (up to 500W) fiber lasers in a range of precision cutting, fusion-welding and additive manufacturing applications.

  1. Determination of Caffeine in Beverages by High Performance Liquid Chromatography.

    ERIC Educational Resources Information Center

    DiNunzio, James E.

    1985-01-01

    Describes the equipment, procedures, and results for the determination of caffeine in beverages by high performance liquid chromatography. The method is simple, fast, accurate, and, because sample preparation is minimal, it is well suited for use in a teaching laboratory. (JN)

  2. Cobra Strikes! High-Performance Car Inspires Students, Markets Program

    ERIC Educational Resources Information Center

    Jenkins, Bonita

    2008-01-01

    Nestled in the Lower Piedmont region of upstate South Carolina, Piedmont Technical College (PTC) is one of 16 technical colleges in the state. Automotive technology is one of its most popular programs. The program features an instructive, motivating activity that the author describes in this article: building a high-performance car. The Cobra…

  3. NAVIGATION PERFORMANCE IN HIGH EARTH ORBITS USING NAVIGATOR GPS RECEIVER

    NASA Technical Reports Server (NTRS)

    Bamford, William; Naasz, Bo; Moreau, Michael C.

    2006-01-01

    NASA GSFC has developed a GPS receiver that can acquire and track GPS signals with sensitivity significantly lower than conventional GPS receivers. This opens up the possibility of using GPS based navigation for missions in high altitude orbit, such as Geostationary Operational Environmental Satellites (GOES) in a geostationary orbit, and the Magnetospheric MultiScale (MMS) Mission, in highly eccentric orbits extending to 12 Earth radii and higher. Indeed much research has been performed to study the feasibility of using GPS navigation in high Earth orbits and the performance achievable. Recently, GSFC has conducted a series of hardware in-the-loop tests to assess the performance of this new GPS receiver in various high Earth orbits of interest. Tracking GPS signals to down to approximately 22-25 dB-Hz, including signals from the GPS transmitter side-lobes, steady-state navigation performance in a geostationary orbit is on the order of 10 meters. This paper presents the results of these tests, as well as sensitivity analysis to such factors as ionosphere masks, use of GPS side-lobe signals, and GPS receiver sensitivity.

  4. Teacher and Leader Effectiveness in High-Performing Education Systems

    ERIC Educational Resources Information Center

    Darling-Hammond, Linda, Ed.; Rothman, Robert, Ed.

    2011-01-01

    The issue of teacher effectiveness has risen rapidly to the top of the education policy agenda, and the federal government and states are considering bold steps to improve teacher and leader effectiveness. One place to look for ideas is the experiences of high-performing education systems around the world. Finland, Ontario, and Singapore all have…

  5. Maintaining High-Performance Schools after Construction or Renovation

    ERIC Educational Resources Information Center

    Luepke, Gary; Ronsivalli, Louis J., Jr.

    2009-01-01

    With taxpayers' considerable investment in schools, it is critical for school districts to preserve their community's assets with new construction or renovation and effective facility maintenance programs. "High-performance" school buildings are designed to link the physical environment to positive student achievement while providing such benefits…

  6. American Models of High-Performance Work Systems.

    ERIC Educational Resources Information Center

    Appelbaum, Eileen; Batt, Rosemary

    1993-01-01

    Looks at work systems that draw on quality engineering and management concepts and use incentives. Discusses how some U.S. companies improve performance and maintain high quality. Suggests that the federal government strategy should include measures to support change in production processes and promote efficient factors of production. (JOW)

  7. A Research and Development Strategy for High Performance Computing.

    ERIC Educational Resources Information Center

    Office of Science and Technology Policy, Washington, DC.

    This report is the result of a systematic review of the status and directions of high performance computing and its relationship to federal research and development. Conducted by the Federal Coordinating Council for Science, Engineering, and Technology (FCCSET), the review involved a series of workshops attended by numerous computer scientists and…

  8. Rotordynamic Instability Problems in High-Performance Turbomachinery

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Diagnostic and remedial methods concerning rotordynamic instability problems in high performance turbomachinery are discussed. Instabilities due to seal forces and work-fluid forces are identified along with those induced by rotor bearing systems. Several methods of rotordynamic control are described including active feedback methods, the use of elastometric elements, and the use of hydrodynamic journal bearings and supports.

  9. Dynamic Social Networks in High Performance Football Coaching

    ERIC Educational Resources Information Center

    Occhino, Joseph; Mallett, Cliff; Rynne, Steven

    2013-01-01

    Background: Sports coaching is largely a social activity where engagement with athletes and support staff can enhance the experiences for all involved. This paper examines how high performance football coaches develop knowledge through their interactions with others within a social learning theory framework. Purpose: The key purpose of this study…

  10. Mechanisms to create high performance pseudo-ductile composites

    NASA Astrophysics Data System (ADS)

    Wisnom, M. R.

    2016-07-01

    Current composites normally fail suddenly and catastrophically, which is an undesirable characteristic for many applications. This paper describes work as part of the High Performance Ductile Composite Technology programme (HiPerDuCT) on mechanisms to overcome this key limitation and introduce pseudo-ductility into the failure process.

  11. High-definition television evaluation for remote handling task performance

    SciTech Connect

    Fujita, Y.; Omori, E.; Hayashi, S.; Draper, J.V.; Herndon, J.N.

    1986-01-01

    This paper describes experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The experiments described in this paper compared the performance of four operators using HDTV with their performance while using other television systems. The experiments included four television systems: (1) high-definition color television, (2) high-definition monochromatic television, (3) standard-resolution monochromatic television, and (4) standard-resolution stereoscopic monochromatic television. The stereo system accomplished stereoscopy by displaying two cross-polarized images, one reflected by a half-silvered mirror and one seen through the mirror. Observers wore a pair of glasses with cross-polarized lenses so that the left eye received only the view from the left camera and the right eye received only the view from the right camera.

  12. The Deformability of a High Performance Concrete (HPC)

    NASA Astrophysics Data System (ADS)

    Benamara, Dalila; Mezghiche, Bouzidi; Zohra, Mechrouh Fatma

    The current tendency in the world is to find new materials at lower cost which can guarantee better performances during their incorporations in the concretes. Our study lies within the scope of the valorization of local materials. Among these materials we find the high performance concrete, which has become the object of the several researchers for a few years. This study consists the development and the mechanical and elastic properties of a concrete with high performances (HPC) starting from materials existing on the Algerian market. Three mineral additions: limestone, the sand of dune and the waste of polishing of tiling are incorporated a cement with various contents (5%, 10%, 15% and 20%). instead of the fume of silica or fly-ashes.

  13. Building and measuring a high performance network architecture

    SciTech Connect

    Kramer, William T.C.; Toole, Timothy; Fisher, Chuck; Dugan, Jon; Wheeler, David; Wing, William R; Nickless, William; Goddard, Gregory; Corbato, Steven; Love, E. Paul; Daspit, Paul; Edwards, Hal; Mercer, Linden; Koester, David; Decina, Basil; Dart, Eli; Paul Reisinger, Paul; Kurihara, Riki; Zekauskas, Matthew J; Plesset, Eric; Wulf, Julie; Luce, Douglas; Rogers, James; Duncan, Rex; Mauth, Jeffery

    2001-04-20

    Once a year, the SC conferences present a unique opportunity to create and build one of the most complex and highest performance networks in the world. At SC2000, large-scale and complex local and wide area networking connections were demonstrated, including large-scale distributed applications running on different architectures. This project was designed to use the unique opportunity presented at SC2000 to create a testbed network environment and then use that network to demonstrate and evaluate high performance computational and communication applications. This testbed was designed to incorporate many interoperable systems and services and was designed for measurement from the very beginning. The end results were key insights into how to use novel, high performance networking technologies and to accumulate measurements that will give insights into the networks of the future.

  14. High performance computing with a conservative spectral Boltzmann solver

    NASA Astrophysics Data System (ADS)

    Haack, Jeffrey R.; Gamba, Irene M.

    2012-11-01

    We present new results building on the conservative deterministic spectral method for the space inhomogeneous Boltzmann equation developed by Gamba and Tharkabhushaman. This approach is a two-step process that acts on the weak form of the Boltzmann equation, and uses the machinery of the Fourier transform to reformulate the collisional integral into a weighted convolution in Fourier space. A constrained optimization problem is solved to preserve the mass, momentum, and energy of the resulting distribution. We extend this method to second order accuracy in space and time, and explore how to leverage the structure of the collisional formulation for high performance computing environments. The locality in space of the collisional term provides a straightforward memory decomposition, and we perform some initial scaling tests on high performance computing resources. We also use the improved computational power of this method to investigate a boundary-layer generated shock problem that cannot be described by classical hydrodynamics.

  15. 1997 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

    NASA Technical Reports Server (NTRS)

    Baize, Daniel G. (Editor)

    1999-01-01

    The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Aerodynamic Performance Workshop on February 25-28, 1997. The workshop was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag, prediction and minimization), High-Lift, Flight Controls, Supersonic Laminar Flow Control, and Sonic Boom Prediction. The workshop objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT Motion Simulator results were presented along with executives summaries for all the Aerodynamic Performance technology areas.

  16. Phenomena and Performance of High-Efficiency Split Spectrum Photovoltaics

    NASA Astrophysics Data System (ADS)

    Downs, Chandler

    High-efficiency photovoltaics are one of the most promising technologies for supplying sustainable energy in the near future. These technologies allow for high energy conversion efficiencies and long system lifetimes, which is becoming an increasingly profitable power generation option. One high-efficiency photovoltaic technology gaining increasing attention recent years is that of split-spectrum photovoltaics. This technology divides the incident solar spectrum on the basis of wavelength, directing each portion of the spectrum to a different cell where the light can be utilized most efficiently. In this dissertation, a number of aspects of high-efficiency photovoltaics, most notably split-spectrum photovoltaics, are examined. First, the ideal bandgap placements of the subcells of a split-spectrum photovoltaic system are calculated, specifically determined with an eye towards practical fabrication of the cells. Two viable designs are determined which improve theoretical absolute conversion efficiency by 4-5%. Next, those systems are simulated using the TCAD Sentaurus software package to project conversion efficiencies and determine additional device specifications (doping levels, layer thicknesses, etc.). These cells show comparable conversion efficiencies to high performing, full-spectrum multijunction photovoltaics in fabrication today. In the last section, a theoretical examination of semiconductor performance under high optical concentration is performed, including the prediction and characterization of various phenomena in those devices. This work aims to improve the understanding of the performance of high concentration photovoltaics, most notably split-spectrum photovoltaics. This understanding will aid in the advancement of this technology as a widespread, sustainable energy source for use worldwide, reducing greenhouse emissions and providing cheap, clean energy.

  17. Removal of H2S using molten carbonate at high temperature.

    PubMed

    Kawase, Makoto; Otaka, Maromu

    2013-12-01

    Gasification is considered to be an effective process for energy conversion from various sources such as coal, biomass, and waste. Cleanup of the hot syngas produced by such a process may improve the thermal efficiency of the overall gasification system. Therefore, the cleanup of hot syngas from biomass gasification using molten carbonate is investigated in bench-scale tests. Molten carbonate acts as an absorbent during desulfurization and dechlorination and as a thermal catalyst for tar cracking. In this study, the performance of molten carbonate for removing H2S was evaluated. The temperature of the molten carbonate was set within the range from 800 to 1000 °C. It is found that the removal of H2S is significantly affected by the concentration of CO2 in the syngas. When only a small percentage of CO2 is present, desulfurization using molten carbonate is inadequate. However, when carbon elements, such as char and tar, are continuously supplied, H2S removal can be maintained at a high level. To confirm the performance of the molten carbonate gas-cleaning system, purified biogas was used as a fuel in power generation tests with a molten carbonate fuel cell (MCFC). The fuel cell is a high-performance sensor for detecting gaseous impurities. When purified gas from a gas-cleaning reactor was continuously supplied to the fuel cell, the cell voltage remained stable. Thus, the molten carbonate gas-cleaning reactor was found to afford good gas-cleaning performance.

  18. High performance hybrid magnetic structure for biotechnology applications

    DOEpatents

    Humphries, David E; Pollard, Martin J; Elkin, Christopher J

    2005-10-11

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

  19. High performance hybrid magnetic structure for biotechnology applications

    DOEpatents

    Humphries, David E.; Pollard, Martin J.; Elkin, Christopher J.

    2006-12-12

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

  20. Tough, high performance, addition-type thermoplastic polymers

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor)

    1992-01-01

    A tough, high performance polyimide is provided by reacting a triple bond conjugated with an aromatic ring in a bisethynyl compound with the active double bond in a compound containing a double bond activated toward the formation of a Diels-Adler type adduct, especially a bismaleimide, a biscitraconimide, or a benzoquinone, or mixtures thereof. Addition curing of this product produces a high linear polymeric structure and heat treating the highly linear polymeric structure produces a thermally stable aromatic addition-type thermoplastic polyimide, which finds utility in the preparation of molding compounds, adhesive compositions, and polymer matrix composites.

  1. High performance protection circuit for power electronics applications

    SciTech Connect

    Tudoran, Cristian D. Dădârlat, Dorin N.; Toşa, Nicoleta; Mişan, Ioan

    2015-12-23

    In this paper we present a high performance protection circuit designed for the power electronics applications where the load currents can increase rapidly and exceed the maximum allowed values, like in the case of high frequency induction heating inverters or high frequency plasma generators. The protection circuit is based on a microcontroller and can be adapted for use on single-phase or three-phase power systems. Its versatility comes from the fact that the circuit can communicate with the protected system, having the role of a “sensor” or it can interrupt the power supply for protection, in this case functioning as an external, independent protection circuit.

  2. IBM SP high-performance networking with a GRF.

    SciTech Connect

    Navarro, J.P.

    1999-05-27

    Increasing use of highly distributed applications, demand for faster data exchange, and highly parallel applications can push the limits of conventional external networking for IBM SP sites. In technical computing applications we have observed a growing use of a pipeline of hosts and networks collaborating to collect, process, and visualize large amounts of realtime data. The GRF, a high-performance IP switch from Ascend and IBM, is the first backbone network switch to offer a media card that can directly connect to an SP Switch. This enables switch attached hosts in an SP complex to communicate at near SP Switch speeds with other GRF attached hosts and networks.

  3. High-Performance, Semi-Interpenetrating Polymer Network

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H.; Lowther, Sharon E.; Smith, Janice Y.; Cannon, Michelle S.; Whitehead, Fred M.; Ely, Robert M.

    1992-01-01

    High-performance polymer made by new synthesis in which one or more easy-to-process, but brittle, thermosetting polyimides combined with one or more tough, but difficult-to-process, linear thermoplastics to yield semi-interpenetrating polymer network (semi-IPN) having combination of easy processability and high tolerance to damage. Two commercially available resins combined to form tough, semi-IPN called "LaRC-RP49." Displays improvements in toughness and resistance to microcracking. LaRC-RP49 has potential as high-temperature matrix resin, adhesive, and molding resin. Useful in aerospace, automotive, and electronic industries.

  4. A secure communications infrastructure for high-performance distributed computing

    SciTech Connect

    Foster, I.; Koenig, G.; Tuecke, S.

    1997-08-01

    Applications that use high-speed networks to connect geographically distributed supercomputers, databases, and scientific instruments may operate over open networks and access valuable resources. Hence, they can require mechanisms for ensuring integrity and confidentially of communications and for authenticating both users and resources. Security solutions developed for traditional client-server applications do not provide direct support for the program structures, programming tools, and performance requirements encountered in these applications. The authors address these requirements via a security-enhanced version of the Nexus communication library; which they use to provide secure versions of parallel libraries and languages, including the Message Passing Interface. These tools permit a fine degree of control over what, where, and when security mechanisms are applied. In particular, a single application can mix secure and nonsecure communication, allowing the programmer to make fine-grained security/performance tradeoffs. The authors present performance results that quantify the performance of their infrastructure.

  5. The architecture of the High Performance Storage System (HPSS)

    SciTech Connect

    Teaff, D.; Coyne, B.; Watson, D.

    1995-01-01

    The rapid growth in the size of datasets has caused a serious imbalance in I/O and storage system performance and functionality relative to application requirements and the capabilities of other system components. The High Performance Storage System (HPSS) is a scalable, next-generation storage system that will meet the functionality and performance requirements of large-scale scientific and commercial computing environments. Our goal is to improve the performance and capacity of storage systems by two orders of magnitude or more over what is available in the general or mass marketplace today. We are also providing corresponding improvements in architecture and functionality. This paper describes the architecture and functionality of HPSS.

  6. Memory Benchmarks for SMP-Based High Performance Parallel Computers

    SciTech Connect

    Yoo, A B; de Supinski, B; Mueller, F; Mckee, S A

    2001-11-20

    As the speed gap between CPU and main memory continues to grow, memory accesses increasingly dominates the performance of many applications. The problem is particularly acute for symmetric multiprocessor (SMP) systems, where the shared memory may be accessed concurrently by a group of threads running on separate CPUs. Unfortunately, several key issues governing memory system performance in current systems are not well understood. Complex interactions between the levels of the memory hierarchy, buses or switches, DRAM back-ends, system software, and application access patterns can make it difficult to pinpoint bottlenecks and determine appropriate optimizations, and the situation is even more complex for SMP systems. To partially address this problem, we formulated a set of multi-threaded microbenchmarks for characterizing and measuring the performance of the underlying memory system in SMP-based high-performance computers. We report our use of these microbenchmarks on two important SMP-based machines. This paper has four primary contributions. First, we introduce a microbenchmark suite to systematically assess and compare the performance of different levels in SMP memory hierarchies. Second, we present a new tool based on hardware performance monitors to determine a wide array of memory system characteristics, such as cache sizes, quickly and easily; by using this tool, memory performance studies can be targeted to the full spectrum of performance regimes with many fewer data points than is otherwise required. Third, we present experimental results indicating that the performance of applications with large memory footprints remains largely constrained by memory. Fourth, we demonstrate that thread-level parallelism further degrades memory performance, even for the latest SMPs with hardware prefetching and switch-based memory interconnects.

  7. Performance evaluation of high modulus asphalt concrete mixes

    NASA Astrophysics Data System (ADS)

    Haritonovs, V.; Tihonovs, J.; Zaumanis, M.

    2016-04-01

    Dolomite is one of the most available sedimentary rocks in the territory of Latvia. Dolomite quarries contain about 1000 million tons of this material. However, according to Latvian Road Specifications, this dolomite cannot be used for average and high intensity roads because of its low quality (mainly, LA index). Therefore, mostly imported magmatic rocks (granite, diabase, gabbro, basalt) or imported dolomite are used which makes asphalt expensive. However, practical experience shows that even with these high quality materials roads exhibit rutting, fatigue and thermal cracks. The aim of the research is to develop a high performance asphalt concrete for base and binder courses using only locally available aggregates. In order to achieve resistance against deformations at a high ambient temperature, a hard grade binder was used. Workability, fatigue and thermal cracking resistance, as well as sufficient water resistance is achieved by low porosity (3-5%) and higher binder content compared to traditional asphalt mixtures. The design of the asphalt includes a combination of empirical and performance based tests, which in laboratory circumstances allow simulating traffic and environmental loads. High performance AC 16 base asphalt concrete was created using local dolomite aggregate with polymer modified (PMB 10/40-65) and hard grade (B20/30) bitumen. The mixtures were specified based on fundamental properties in accordance to EN 13108-1 standard.

  8. High-performance supported Ir-oxohydroxide water oxidation electrocatalysts.

    PubMed

    Massue, Cyriac; Pfeifer, Verena; Huang, Xing; Noack, Johannes; Tarasov, Andrey; Cap, Sebastien; Schlögl, Robert

    2017-02-05

    The synthesis of a highly active and yet stable electrocatalyst for the anodic oxygen evolution reaction (OER) remains a major challenge for acidic water splitting on an industrial scale. Addressing this challenge, we obtained an outstanding high-performance OER-electrocatalyst by loading Ir on conductive antimony-doped tin oxide (ATO)-nanoparticles via a microwave (MW)-supported hydrothermal route. The obtained Ir-phase was identified as an XRD-amorphous, highly hydrated Ir(III/IV)-oxohydroxide. In order to identify chemical and structural features responsible for the high activity and exceptional stability under acidic OER-conditions at loadings as low as 20 μg(Ir) cm-2, we used stepwise thermal treatment to gradually alter the XRD-amorphous Ir-phase via dehydroxylation and crystallization of IrO2. This resulted in dramatic depletion of OER-performance, indicating that the outstanding electrocatalytic properties of the MW-produced Ir(III/IV)-oxohydroxide are prominently linked to the nature of the produced Ir-phase. This finding is in contrast with the often reported stable but poor OER-performance of crystalline IrO2-based compounds produced via more classical calcination routes. Our investigation demonstrates the immense potential of Ir-oxohydroxide-based OER electrocatalysts for stable high-current water electrolysis under acidic conditions.

  9. Experimental Evaluation of High Performance Integrated Heat Pump

    SciTech Connect

    Miller, William A; Berry, Robert; Durfee, Neal; Baxter, Van D

    2016-01-01

    Integrated heat pump (IHP) technology provides significant potential for energy savings and comfort improvement for residential buildings. In this study, we evaluate the performance of a high performance IHP that provides space heating, cooling, and water heating services. Experiments were conducted according to the ASHRAE Standard 206-2013 where 24 test conditions were identified in order to evaluate the IHP performance indices based on the airside performance. Empirical curve fits of the unit s compressor maps are used in conjunction with saturated condensing and evaporating refrigerant conditions to deduce the refrigerant mass flowrate, which, in turn was used to evaluate the refrigerant side performance as a check on the airside performance. Heat pump (compressor, fans, and controls) and water pump power were measured separately per requirements of Standard 206. The system was charged per the system manufacturer s specifications. System test results are presented for each operating mode. The overall IHP performance metrics are determined from the test results per the Standard 206 calculation procedures.

  10. Multijunction Photovoltaic Technologies for High-Performance Concentrators: Preprint

    SciTech Connect

    McConnell, R.; Symko-Davies, M.

    2006-05-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  11. Micromachined high-performance RF passives in CMOS substrate

    NASA Astrophysics Data System (ADS)

    Li, Xinxin; Ni, Zao; Gu, Lei; Wu, Zhengzheng; Yang, Chen

    2016-11-01

    This review systematically addresses the micromachining technologies used for the fabrication of high-performance radio-frequency (RF) passives that can be integrated into low-cost complementary metal-oxide semiconductor (CMOS)-grade (i.e. low-resistivity) silicon wafers. With the development of various kinds of post-CMOS-compatible microelectromechanical systems (MEMS) processes, 3D structural inductors/transformers, variable capacitors, tunable resonators and band-pass/low-pass filters can be compatibly integrated into active integrated circuits to form monolithic RF system-on-chips. By using MEMS processes, including substrate modifying/suspending and LIGA-like metal electroplating, both the highly lossy substrate effect and the resistive loss can be largely eliminated and depressed, thereby meeting the high-performance requirements of telecommunication applications.

  12. Hydrazine Determination in Sludge Samples by High Performance Liquid Chromatography

    SciTech Connect

    G. Elias; G. A. Park

    2006-02-01

    A high-performance liquid chromatographic method using ultraviolet (UV) detection was developed to detect and quantify hydrazine in a variety of environmental matrices. The method was developed primarily for sludge samples, but it is also applicable to soil and water samples. The hydrazine in the matrices was derivatized to their hydrazones with benzaldehyde. The derivatized hydrazones were separated using high performance liquid chromatography (HPLC) with a reversed-phase C-18 column in an isocratic mode with methanol-water (95:5, v/v), and detected with UV detection at 313 nm. The detection limit (25 ml) for the new analytical method is 0.0067 mg ml-1of hydrazine. Hydrazine showed low recovery in soil samples because components in soil oxidized hydrazine. Sludge samples that contained relatively high soil content also showed lower recovery. The technique is relatively simple and cost-effective, and is applicable for hydrazine analysis in different environmental matrices.

  13. Designing high-performance layered thermoelectric materials through orbital engineering

    PubMed Central

    Zhang, Jiawei; Song, Lirong; Madsen, Georg K. H.; Fischer, Karl F. F.; Zhang, Wenqing; Shi, Xun; Iversen, Bo B.

    2016-01-01

    Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet successful strategy to discover and design high-performance layered thermoelectric materials through minimizing the crystal field splitting energy of orbitals to realize high orbital degeneracy. The approach naturally leads to design maps for optimizing the thermoelectric power factor through forming solid solutions and biaxial strain. Using this approach, we predict a series of potential thermoelectric candidates from layered CaAl2Si2-type Zintl compounds. Several of them contain nontoxic, low-cost and earth-abundant elements. Moreover, the approach can be extended to several other non-cubic materials, thereby substantially accelerating the screening and design of new thermoelectric materials. PMID:26948043

  14. Semiconducor wires and ribbons for high performance flexible electronics.

    SciTech Connect

    Sun, Y.; Baca, A. J.; Ahn, J.-H.; Meitl, M.; Menard, E.; Kim, H.-S; Choi, W.; Kim, D.-H; Huang, Y.; Rogers, J. A.; Center for Nanoscale Materials; Univ. of Illinois

    2008-01-01

    This article reviews the properties, fabrication and assembly of inorganic semiconductor materials that can be used as active building blocks to form high-performance transistors and circuits for flexible and bendable large-area electronics. Obtaining high performance on low temperature polymeric substrates represents a technical challenge for macroelectronics. Therefore, the fabrication of high quality inorganic materials in the form of wires, ribbons, membranes, sheets, and bars formed by bottom-up and top-down approaches, and the assembly strategies used to deposit these thin films onto plastic substrates will be emphasized. Substantial progress has been made in creating inorganic semiconducting materials that are stretchable and bendable, and the description of the mechanics of these form factors will be presented, including circuits in three-dimensional layouts. Finally, future directions and promising areas of research will be described.

  15. A System for Performing High Throughput Assays of Synaptic Function

    PubMed Central

    Hempel, Chris M.; Sivula, Michael; Levenson, Jonathan M.; Rose, David M.; Li, Bing; Sirianni, Ana C.; Xia, Eva; Ryan, Timothy A.; Gerber, David J.; Cottrell, Jeffrey R.

    2011-01-01

    Unbiased, high-throughput screening has proven invaluable for dissecting complex biological processes. Application of this general approach to synaptic function would have a major impact on neuroscience research and drug discovery. However, existing techniques for studying synaptic physiology are labor intensive and low-throughput. Here, we describe a new high-throughput technology for performing assays of synaptic function in primary neurons cultured in microtiter plates. We show that this system can perform 96 synaptic vesicle cycling assays in parallel with high sensitivity, precision, uniformity, and reproducibility and can detect modulators of presynaptic function. By screening libraries of pharmacologically defined compounds on rat forebrain cultures, we have used this system to identify novel effects of compounds on specific aspects of presynaptic function. As a system for unbiased compound as well as genomic screening, this technology has significant applications for basic neuroscience research and for the discovery of novel, mechanism-based treatments for central nervous system disorders. PMID:21998743

  16. Jules Horowitz Reactor: a high performance material testing reactor

    NASA Astrophysics Data System (ADS)

    Iracane, Daniel; Chaix, Pascal; Alamo, Ana

    2008-04-01

    The physical modelling of materials' behaviour under severe conditions is an indispensable element for developing future fission and fusion systems: screening, design, optimisation, processing, licensing, and lifetime assessment of a new generation of structure materials and fuels, which will withstand high fast neutron flux at high in-service temperatures with the production of elements like helium and hydrogen. JANNUS and other analytical experimental tools are developed for this objective. However, a purely analytical approach is not sufficient: there is a need for flexible experiments integrating higher scales and coupled phenomena and offering high quality measurements; these experiments are performed in material testing reactors (MTR). Moreover, complementary representative experiments are usually performed in prototypes or dedicated facilities such as IFMIF for fusion. Only such a consistent set of tools operating on a wide range of scales, can provide an actual prediction capability. A program such as the development of silicon carbide composites (600-1200 °C) illustrates this multiscale strategy. Facing the long term needs of experimental irradiations and the ageing of present MTRs, it was thought necessary to implement a new generation high performance MTR in Europe for supporting existing and future nuclear reactors. The Jules Horowitz Reactor (JHR) project copes with this context. It is funded by an international consortium and will start operation in 2014. JHR will provide improved performances such as high neutron flux ( 10 n/cm/s above 0.1 MeV) in representative environments (coolant, pressure, temperature) with online monitoring of experimental parameters (including stress and strain control). Experimental devices designing, such as high dpa and small thermal gradients experiments, is now a key objective requiring a broad collaboration to put together present scientific state of art, end-users requirements and advanced instrumentation. To cite this

  17. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1996-01-23

    A high performance capacitor is described which is fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a ``notepad`` configuration composed of 200--300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The ``notepad`` capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density. 5 figs.

  18. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, Jr., Troy W.; Johnson, Gary W.; O'Brien, Dennis W.

    1995-01-01

    A high performance capacitor fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a "notepad" configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The "notepad" capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density.

  19. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1995-05-09

    A high performance capacitor is fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a ``notepad`` configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The notepad capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density. 5 figs.

  20. High performance capacitors using nano-structure multilayer materials fabrication

    DOEpatents

    Barbee, Jr., Troy W.; Johnson, Gary W.; O'Brien, Dennis W.

    1996-01-01

    A high performance capacitor fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a "notepad" configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The "notepad" capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density.

  1. Parallel Reaction Monitoring: A Targeted Experiment Performed Using High Resolution and High Mass Accuracy Mass Spectrometry

    PubMed Central

    Rauniyar, Navin

    2015-01-01

    The parallel reaction monitoring (PRM) assay has emerged as an alternative method of targeted quantification. The PRM assay is performed in a high resolution and high mass accuracy mode on a mass spectrometer. This review presents the features that make PRM a highly specific and selective method for targeted quantification using quadrupole-Orbitrap hybrid instruments. In addition, this review discusses the label-based and label-free methods of quantification that can be performed with the targeted approach. PMID:26633379

  2. Highlighting High Performance: Blackstone Valley Regional Vocational Technical High School; Upton, Massachusetts

    SciTech Connect

    Not Available

    2006-10-01

    This brochure describes the key high-performance building features of the Blackstone Valley High School. The brochure was paid for by the Massachusetts Technology Collaborative as part of their Green Schools Initiative. High-performance features described are daylighting and energy-efficient lighting, indoor air quality, solar energy, building envelope, heating and cooling systems, and water conservation. Energy cost savings are also discussed.

  3. High performance computing and communications: Investment in American competitiveness

    NASA Astrophysics Data System (ADS)

    1991-03-01

    This report presents the results of a study performed by Gartner Group, Inc. for the U.S. Department of Energy (DOE), through a contract with the Los Alamos National Laboratory (LANL). The purpose of the study is to estimate the economic impact of the Federal High Performance Computing and Communications (HPCC) Program which was proposed by the Office of Science and Technology Policy (OSTP), Executive Office of the President, on September 8, 1989. That Program is an implementation of the Research and Development Strategy for High Performance Computing, which was transmitted to Congress by OSTP on November 20, 1988. The objective of this Gartner Group study to provide an assessment of the likely economic impact and benefits of the Federal HPCC Program and the risks of non-support of this program. The goals of the HPCC Program are to: support computational advances through R and D effort; Reduce uncertainties to industry through increased cooperation and continued use of government as a market for High Performance Computing (HPC) prototypes; Support underlying research, network, and computational infrastructures; and support the U.S. human resource base.

  4. Development of high performance sodium/metal chloride cells

    NASA Astrophysics Data System (ADS)

    Vissers, D. R.; Bloom, I. D.; Hash, M. C.; Redey, L.; Hammer, C. L.; Dees, D. W.; Nelson, P. A.

    Sodium/metal chloride (MCl2) cells and batteries are being studied at Argonne National Laboratory (ANL) for stationary energy storage and transportation applications. The work is being directed toward (1) development of thin, high capacity density electrodes and inexpensive beta double prime alumina-glass composite electrolyte materials to replace beta double prime alumina, and (2) the development of models to project MCl2 system performances. In our NiCl2 electrode work, the effects of charge/discharge rates, temperature, electrode porosity, and sulfur content on electrode performance were determined using annular electrodes fabricated in the uncharged state. Of all electrode design parameters mentioned, electrode porosity, sulfur content, and charge rates have the greatest effect on utilization and on the area-specific impedance. The beta double prime alumina-glass composite electrolyte work has led to the development of a highly conductive (3.3 x 10(exp -2)S/cm at 250 C) composite material. Preliminary modeling studies indicate that the performance of the MCl2 electrodes can be fitted by a mathematic model very successfully and that cell electrolyte configurations of either multiple tubes joined at a header or compartmented flat structures of either beta double prime alumina or of the composite material would result in high performance batteries with power-to-energy ratios of about 5.

  5. High-Performance Computing for Advanced Smart Grid Applications

    SciTech Connect

    Huang, Zhenyu; Chen, Yousu

    2012-07-06

    The power grid is becoming far more complex as a result of the grid evolution meeting an information revolution. Due to the penetration of smart grid technologies, the grid is evolving as an unprecedented speed and the information infrastructure is fundamentally improved with a large number of smart meters and sensors that produce several orders of magnitude larger amounts of data. How to pull data in, perform analysis, and put information out in a real-time manner is a fundamental challenge in smart grid operation and planning. The future power grid requires high performance computing to be one of the foundational technologies in developing the algorithms and tools for the significantly increased complexity. New techniques and computational capabilities are required to meet the demands for higher reliability and better asset utilization, including advanced algorithms and computing hardware for large-scale modeling, simulation, and analysis. This chapter summarizes the computational challenges in smart grid and the need for high performance computing, and present examples of how high performance computing might be used for future smart grid operation and planning.

  6. Performance Characterization of High Energy Commercial Lithium-ion Cells

    NASA Technical Reports Server (NTRS)

    Schneidegger, Brianne T.

    2010-01-01

    The NASA Glenn Research Center Electrochemistry Branch performed characterization of commercial lithium-ion cells to determine the cells' performance against Exploration Technology Development Program (ETDP) Key Performance Parameters (KPP). The goals of the ETDP Energy Storage Project require significant improvements in the specific energy of lithium-ion technology over the state-of-the-art. This work supports the high energy cell development for the Constellation customer Lunar Surface Systems (LSS). In support of these goals, testing was initiated in September 2009 with high energy cylindrical cells obtained from Panasonic and E-One Moli. Both manufacturers indicated the capability of their cells to deliver specific energy of at least 180 Wh/kg or higher. Testing is being performed at the NASA Glenn Research Center to evaluate the performance of these cells under temperature, rate, and cycling conditions relevant to the ETDP goals for high energy cells. The cell-level specific energy goal for high energy technology is 180 Wh/kg at a C/10 rate and 0 C. The threshold value is 165 Wh/kg. The goal is to operate for at least 2000 cycles at 100 percent DOD with greater than 80 percent capacity retention. The Panasonic NCR18650 cells were able to deliver nearly 200 Wh/kg at the aforementioned conditions. The E-One Moli ICR18650J cells also met the specific energy goal by delivering 183 Wh/kg. Though both cells met the goal for specific energy, this testing was only one portion of the testing required to determine the suitability of commercial cells for the ETDP. The cells must also meet goals for cycle life and safety. The results of this characterization are summarized in this report.

  7. High-performance superconductors for Fusion Nuclear Science Facility

    SciTech Connect

    Zhai, Yuhu; Kessel, Chuck; Barth, Christian; Senatore, Carmine

    2016-11-09

    High-performance superconducting magnets play an important role in the design of the next step large-scale, high-field fusion reactors such as the fusion nuclear science facility (FNSF) and the spherical tokamak (ST) pilot plant beyond ITER. Here, Princeton Plasma Physics Laboratory is currently leading the design studies of the FNSF and the ST pilot plant study. ITER, which is under construction in the south of France, utilizes the state-of-the-art low temperature superconducting magnet technology based on the cable-in-conduit conductor design, where over a thousand multifilament Nb3Sn superconducting strands are twisted together to form a high-current-carrying cable inserted into a steel jacket for coil windings. We present design options of the high-performance superconductors in the winding pack for the FNSF toroidal field magnet system based on the toroidal field radial build from the system code. For the low temperature superconductor options, the advanced JcNb3Sn RRP strands (Jc > 1000 A/mm2 at 16 T, 4 K) from Oxford Superconducting Technology are under consideration. For the high-temperature superconductor options, the rectangular-shaped high-current HTS cable made of stacked YBCO tapes will be considered to validate feasibility of TF coil winding pack design for the ST-FNSF magnets.

  8. High-performance superconductors for Fusion Nuclear Science Facility

    DOE PAGES

    Zhai, Yuhu; Kessel, Chuck; Barth, Christian; ...

    2016-11-09

    High-performance superconducting magnets play an important role in the design of the next step large-scale, high-field fusion reactors such as the fusion nuclear science facility (FNSF) and the spherical tokamak (ST) pilot plant beyond ITER. Here, Princeton Plasma Physics Laboratory is currently leading the design studies of the FNSF and the ST pilot plant study. ITER, which is under construction in the south of France, utilizes the state-of-the-art low temperature superconducting magnet technology based on the cable-in-conduit conductor design, where over a thousand multifilament Nb3Sn superconducting strands are twisted together to form a high-current-carrying cable inserted into a steel jacketmore » for coil windings. We present design options of the high-performance superconductors in the winding pack for the FNSF toroidal field magnet system based on the toroidal field radial build from the system code. For the low temperature superconductor options, the advanced JcNb3Sn RRP strands (Jc > 1000 A/mm2 at 16 T, 4 K) from Oxford Superconducting Technology are under consideration. For the high-temperature superconductor options, the rectangular-shaped high-current HTS cable made of stacked YBCO tapes will be considered to validate feasibility of TF coil winding pack design for the ST-FNSF magnets.« less

  9. A high-performance digital system for electrical capacitance tomography

    NASA Astrophysics Data System (ADS)

    Cui, Ziqiang; Wang, Huaxiang; Chen, Zengqiang; Xu, Yanbin; Yang, Wuqiang

    2011-05-01

    This paper describes a recently developed digital-based data acquisition system for electrical capacitance tomography (ECT). The system consists of high-capacity field-programmable gate arrays (FPGA) and fast data conversion circuits together with a specific signal processing method. In this system, digital phase-sensitive demodulation is implemented. A specific data acquisition scheme is employed to deal with residual charges in each measurement, resulting in a high signal-to-noise ratio (SNR) at high excitation frequency. A high-speed USB interface is employed between the FPGA and a host PC. Software in Visual C++ has been developed to accomplish operational functions. Various tests were performed to evaluate the system, e.g. frame rate, SNR, noise level, linearity, and static and dynamic imaging. The SNR is 60.3 dB at 1542 frames s-1 for a 12-electrode sensor. The mean absolute error between the measured capacitance and the linear fit value is 1.6 fF. The standard deviation of the measurements is in the order of 0.1 fF. The dynamic imaging test demonstrates the advantages of high temporal resolution of the system. The experimental results indicate that the digital signal processing devices can be used to construct a high-performance ECT system.

  10. Evaluation of a high performance fixed-ratio traction drive

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.; Anderson, N. E.; Rohn, D. A.

    1980-01-01

    The results of a test program to evaluate a compact, high performance, fixed ratio traction drive are presented. This transmission, the Nasvytis Multiroller Traction Drive, is a fixed ratio, single stage planetary with two rows of stepped planet rollers. Two versions of the drive were parametrically tested back-to-back at speeds to 73,000 rpm and power levels to 180 kW (240 hp). Parametric tests were also conducted with the Nasvytis drive retrofitted to an automotive gas turbine engine. The drives exhibited good performance, with a nominal peak efficiency of 94 to 96 percent and a maximum speed loss due to creep of approximately 3.5 percent.

  11. Building and managing high performance, scalable, commodity mass storage systems

    NASA Technical Reports Server (NTRS)

    Lekashman, John

    1998-01-01

    The NAS Systems Division has recently embarked on a significant new way of handling the mass storage problem. One of the basic goals of this new development are to build systems at very large capacity and high performance, yet have the advantages of commodity products. The central design philosophy is to build storage systems the way the Internet was built. Competitive, survivable, expandable, and wide open. The thrust of this paper is to describe the motivation for this effort, what we mean by commodity mass storage, what the implications are for a facility that performs such an action, and where we think it will lead.

  12. Parallelized control protocols for high-performance routers

    NASA Astrophysics Data System (ADS)

    Yu, Shao-hua; Ji, Meng

    2005-11-01

    This paper proposes a novel parallelized architecture for control protocols in high-performance routers (HPRs). Unlike traditional centralized manner, this approach distributes the functionality of control plane protocols within a router and achieves scalability by selectively off-loading certain link-layer and interface operations to data plane processing components. This paper presents the design and implementation of this method on a 320Gbps distributed router. The experiment results show that the proposed scheme can yield better performance and faster response than the centralized approach.

  13. Challenges for high-performance networking for exascale computing.

    SciTech Connect

    Barrett, Brian W.; Hemmert, K. Scott; Underwood, Keith Douglas; Brightwell, Ronald Brian

    2010-05-01

    Achieving the next three orders of magnitude performance increase to move from petascale to exascale computing will require a significant advancements in several fundamental areas. Recent studies have outlined many of the challenges in hardware and software that will be needed. In this paper, we examine these challenges with respect to high-performance networking. We describe the repercussions of anticipated changes to computing and networking hardware and discuss the impact that alternative parallel programming models will have on the network software stack. We also present some ideas on possible approaches that address some of these challenges.

  14. High Temperature Performance Evaluation of a Compliant Foil Seal

    NASA Technical Reports Server (NTRS)

    Salehi, Mohsen; Heshmat, Hooshang; Walton, James F., II

    2001-01-01

    The key points to be gleaned from the effort reported herein are that the CFS (Compliant Foil Seal) has been demonstrated in conjunction with a foil bearing in a small gas turbine simulator at temperatures as high as 1000 F and outperformed a comparable brush seal. Having demonstrated the feasibility of the CFS, it would appear that this new seal design has application potential in a wide range of machines. What remains is to demonstrate performance at higher pressure ratios, consistent performance at large rotor excursions and the ability to manufacture the seal in much larger sizes exceeding by an order of magnitude that which has been tested to date.

  15. High Performance Computing with Harness over InfiniBand

    SciTech Connect

    Valentini, Alessandro; Di Biagio, Christian; Batino, Fabrizio; Pennella, Guido; Palma, Fabrizio; Engelmann, Christian

    2009-01-01

    Harness is an adaptable and plug-in-based middleware framework able to support distributed parallel computing. By now, it is based on the Ethernet protocol which cannot guarantee high performance throughput and real time (determinism) performance. During last years, both, the research and industry environments have developed new network architectures (InfiniBand, Myrinet, iWARP, etc.) to avoid those limits. This paper concerns the integration between Harness and InfiniBand focusing on two solutions: IP over InfiniBand (IPoIB) and Socket Direct Protocol (SDP) technology. They allow the Harness middleware to take advantage of the enhanced features provided by the InfiniBand Architecture.

  16. High-performance insulator structures for accelerator applications

    SciTech Connect

    Sampayan, S.E.; Caporaso, G.J.; Sanders, D.M.; Stoddard, R.D.; Trimble, D.O.; Elizondo, J.; Krogh, M.L.; Wieskamp, T.F.

    1997-05-01

    A new, high gradient insulator technology has been developed for accelerator systems. The concept involves the use of alternating layers of conductors and insulators with periods of order 1 mm or less. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We describe our ongoing studies investigating the degradation of the breakdown electric field resulting from alternate fabrication techniques, the effect of gas pressure, the effect of the insulator-to-electrode interface gap spacing, and the performance of the insulator structure under bi-polar stress.

  17. High Performance Imaging Streak Camera for the National Ignition Facility

    SciTech Connect

    Opachich, Y. P.; Kalantar, D.; MacPhee, A.; Holder, J.; Kimbrough, J.; Bell, P. M.; Bradley, D.; Hatch, B.; Brown, C.; Landen, O.; Perfect, B. H.; Guidry, B.; Mead, A.; Charest, M.; Palmer, N.; Homoelle, D.; Browning, D.; Silbernagel, C.; Brienza-Larsen, G.; Griffin, M.; Lee, J. J.; Haugh, M. J.

    2012-01-01

    An x-ray streak camera platform has been characterized and implemented for use at the National Ignition Facility. The camera has been modified to meet the experiment requirements of the National Ignition Campaign and to perform reliably in conditions that produce high EMI. A train of temporal UV timing markers has been added to the diagnostic in order to calibrate the temporal axis of the instrument and the detector efficiency of the streak camera was improved by using a CsI photocathode. The performance of the streak camera has been characterized and is summarized in this paper. The detector efficiency and cathode measurements are also presented.

  18. Revisit of Energy Use and Technologies of High Performance Buildings

    SciTech Connect

    Li, Cheng; Hong, Tianzhen

    2014-03-30

    Energy consumed by buildings accounts for one third of the world?s total primary energy use. Associated with the conscious of energy savings in buildings, High Performance Buildings (HPBs) has surged across the world, with wide promotion and adoption of various performance rating and certification systems. It is valuable to look into the actual energy performance of HPBs and to understand their influencing factors. To shed some light on this topic, this paper conducted a series of portfolio analysis based on a database of 51 high performance office buildings across the world. Analyses showed that the actual site Energy Use Intensity (EUI) of the 51 buildings varied by a factor of up to 11, indicating a large scale of variation of the actual energy performance of the current HPBs. Further analysis of the correlation between EUI and climate elucidated ubiquitous phenomenon of EUI scatter throughout all climate zones, implying that the weather is not a decisive factor, although important, for the actual energy consumption of an individual building. On the building size via EUI, analysis disclosed that smaller buildings have a tendency to achieving lower energy use. Even so, the correlation is not absolute since some large buildings demonstrated low energy use while some small buildings performed opposite. Concerning the technologies, statistics indicated that the application of some technologies had correlations with some specific building size and climate characteristic. However, it was still hard to pinpoint a set of technologies which was directly correlative with a group of low EUI buildings. It is concluded that no a single factor essentially determines the actual energy performance of HPBs. To deliver energy-efficient buildings, an integrated design taking account of climate, technology, occupant behavior as well as operation and maintenance should be implemented.

  19. Evaluation of high-definition television for remote task performance

    SciTech Connect

    Draper, J.V.; Fujita, Y.; Herndon, J.N.

    1987-04-01

    High-definition television (HDTV) transmits a video image with more than twice the number (1125 for HDTV to 525 for standard-resolution TV) of horizontal scan lines that standard-resolution TV provides. The improvement in picture quality (compared to standard-resolution TV) that the extra scan lines provide is impressive. Objects in the HDTV picture have more sharply defined edges, better contrast, and more accurate reproduction of shading and color patterns than do those in the standard-resolution TV picture. Because the TV viewing system is a key component for teleoperator performance, an improvement in TV picture quality could mean an improvement in the speed and accuracy with which teleoperators perform tasks. This report describes three experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The performance of HDTV was compared to that of standard-resolution, monochromatic TV and standard-resolution, stereoscopic, monochromatic TV in the context of judgment of depth in a televised scene, visual inspection of an object, and performance of a typical remote handling task. The results of the three experiments show that in some areas HDTV can lead to improvement in teleoperator performance. Observers inspecting a small object for a flaw were more accurate with HDTV than with either of the standard-resolution systems. High resolution is critical for detection of small-scale flaws of the type in the experiment (a scratch on a glass bottle). These experiments provided an evaluation of HDTV television for use in tasks that must be routinely performed to remotely maintain a nuclear fuel reprocessing facility. 5 refs., 7 figs., 9 tabs.

  20. Coal-fired high performance power generating system. Final report

    SciTech Connect

    1995-08-31

    As a result of the investigations carried out during Phase 1 of the Engineering Development of Coal-Fired High-Performance Power Generation Systems (Combustion 2000), the UTRC-led Combustion 2000 Team is recommending the development of an advanced high performance power generation system (HIPPS) whose high efficiency and minimal pollutant emissions will enable the US to use its abundant coal resources to satisfy current and future demand for electric power. The high efficiency of the power plant, which is the key to minimizing the environmental impact of coal, can only be achieved using a modern gas turbine system. Minimization of emissions can be achieved by combustor design, and advanced air pollution control devices. The commercial plant design described herein is a combined cycle using either a frame-type gas turbine or an intercooled aeroderivative with clean air as the working fluid. The air is heated by a coal-fired high temperature advanced furnace (HITAF). The best performance from the cycle is achieved by using a modern aeroderivative gas turbine, such as the intercooled FT4000. A simplified schematic is shown. In the UTRC HIPPS, the conversion efficiency for the heavy frame gas turbine version will be 47.4% (HHV) compared to the approximately 35% that is achieved in conventional coal-fired plants. This cycle is based on a gas turbine operating at turbine inlet temperatures approaching 2,500 F. Using an aeroderivative type gas turbine, efficiencies of over 49% could be realized in advanced cycle configuration (Humid Air Turbine, or HAT). Performance of these power plants is given in a table.