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Sample records for ele vool jt

  1. JT-60 Control System

    SciTech Connect

    Yonekawa, I.; Kawamata, Y.; Totsuka, T.; Akasaka, H.; Sueoka, M.; Kurihara, K.; Kimura, T.

    2002-09-15

    The present status of the JT-60U control system is reported including its original design concept, the progress of the system, and various modifications since the JT-60 upgrade. This control system has features of a functionally distributed and hierarchical structure, using CAMAC interfaces initially, which have been replaced by versatile module Europe (VME)-bus interfaces, and a protective interlock system composed of both software and hard-wired interlock logics. Plant monitoring and control are performed by efficient data communication through CAMAC highways and Ethernet with TCP/IP protocols. Sequential control of plasma discharges is executed by a combination of a remodeled VME-bus system and a timing system. A real-time plasma control system and a human interface system have been continuously modified corresponding to the progress of JT-60U experiments.

  2. JT8D engine performance retention

    NASA Technical Reports Server (NTRS)

    James, A. D.; Weisel, D. R.

    1981-01-01

    The attractive performance retention characteristics of the JT8D engine are described. Because of its moderate bypass ratio and turbine temperature, and stiff structural design, the performance retention versus flight cycles of the JT8D engine sets a standard that is difficult for other engines to equal. In addition, the significant benefits of refurbishment of the JT8D engine are presented. Cold section refurbishment offers thrust specific fuel consumption improvements of up to 2 percent and payback in less than a year, making a very attractive investment option for the airlines.

  3. The JT8D and JT9D engine component improvement: Performance improvement program

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1982-01-01

    The NASA sponsored Engine Component Improvement - Performance Improvement Program at Pratt & Whitney Aircraft advanced the state of the art of thermal barrier coatings and ceramic seal systems, demonstrated the practicality of an advanced turbine clearance control system and an advanced fan design in the JT9D engine, and demonstrated the advantages of modern cooling, sealing, and aerodynamic designs in the high pressure turbine and compressor of the JT8D engine. Several of these improvements are already in airline service in JT8D and JT9D engines, and others will enter service soon in advanced models of these engines. In addition, the technology advances are being transferred to completely new engine configurations, the PW2037 engine and the NASA sponsored Energy Efficient Engine.

  4. JT8D and JT9D jet engine performance improvement program. Task 1: Feasibility analysis

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.; Webb, D. E.

    1979-01-01

    JT8D and JT9D component performance improvement concepts which have a high probability of incorporation into production engines were identified and ranked. An evaluation method based on airline payback period was developed for the purpose of identifying the most promising concepts. The method used available test data and analytical models along with conceptual/preliminary designs to predict the performance improvements, weight, installation characteristics, cost for new production and retrofit, maintenance cost, and qualitative characteristics of candidate concepts. These results were used to arrive at the concept payback period, which is the time required for an airline to recover the investment cost of concept implementation.

  5. Data Processing and Analysis Systems for JT-60U

    SciTech Connect

    Matsuda, T.; Totsuka, T.; Tsugita, T.; Oshima, T.; Sakata, S.; Sato, M.; Iwasaki, K.

    2002-09-15

    The JT-60U data processing system is a large computer complex gradually modernized by utilizing progressive computer and network technology. A main computer using state-of-the-art CMOS technology can handle {approx}550 MB of data per discharge. A gigabit ethernet switch with FDDI ports has been introduced to cope with the increase of handling data. Workstation systems with VMEbus serial highway drivers for CAMAC have been developed and used to replace many minicomputer systems. VMEbus-based fast data acquisition systems have also been developed to enlarge and replace a minicomputer system for mass data.The JT-60U data analysis system is composed of a JT-60U database server and a JT-60U analysis server, which are distributed UNIX servers. The experimental database is stored in the 1TB RAID disk of the JT-60U database server and is composed of ZENKEI and diagnostic databases. Various data analysis tools are available on the JT-60U analysis server. For the remote collaboration, technical features of the data analysis system have been applied to the computer system to access JT-60U data via the Internet. Remote participation in JT-60U experiments has been successfully conducted since 1996.

  6. Engine component improvement: JT8D and JT9D performance improvements

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1978-01-01

    A feasibility analysis screening method for predicting the airline acceptance of a proposed engine performance improvement modification was developed. Technical information derived from available test data and analytical models is used along with conceptual/preliminary designs to establish the predicted performance improvement, weight and installation characteristics, the cost for new production and retrofit, maintenance cost and qualitative characteristics of the performance improvement concepts being evaluated. These results are used to arrive at the payback period, which is the time required for an airline to recover the investment cost of concept implementation, and to predict the amount of fuel saved by a performance improvement concept. The assumptions used to calculate the payback period and fuel saved are discussed. A summary of the results when the screening method is applied is presented for several representative JT8D and JT9D performance improvement concepts. An example of the input information used to develop the summary results is shown.

  7. JT-60SA superconducting magnet system

    NASA Astrophysics Data System (ADS)

    Koide, Y.; Yoshida, K.; Wanner, M.; Barabaschi, P.; Cucchiaro, A.; Davis, S.; Decool, P.; Di Pietro, E.; Disset, G.; Genini, L.; Hajnal, N.; Heller, R.; Honda, A.; Ikeda, Y.; Kamada, Y.; Kashiwa, Y.; Kizu, K.; Kamiya, K.; Murakami, H.; Michel, F.; Marechal, J. L.; Phillips, G.; Polli, G. M.; Rossi, P.; Shibanuma, K.; Takahata, K.; Tomarchio, V.; Tsuchiya, K.; Usui, K.; Verrecchia, M.; Zani, L.

    2015-08-01

    The most distinctive feature of the superconducting magnet system for JT-60SA is the optimized coil structure in terms of the space utilization as well as the highly accurate coil manufacturing, thus meeting the requirements for the steady-state tokamak research: a conceptually new outer inter-coil structure separated from the casing is introduced to the toroidal field coils to realize their slender shape, allowing large-bore diagnostic ports for detailed plasma measurements. A method to minimize the manufacturing error of the equilibrium-field coils has been established, aiming at the precise plasma shape/position control. A compact butt-joint has been successfully developed for the Central Solenoid, which allows an optimized utilization of the limited space for the Central Solenoid to extend the duration of the plasma pulse.

  8. JT8D-100 turbofan engine, phase 1. [noise reduction

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The JT8D turbofan engine, widely used in short and medium range transport aircraft, contributes substantially to airport community noise. The jet noise is predominant in the JT8D engine and may be reduced in a modified engine, without loss of thrust, by increasing the airflow to reduce jet velocity. A configuration study evaluated the effects of fan airflow, fan pressure ratio, and bypass ratio on noise, thrust, and fuel comsumption. The cycle selected for the modified engine was based upon an increased diameter, single-stage fan and two additional core engine compressor stages, which replace the existing two-stage fan. Modifications were also made to the low pressure turbine to provide the increased torque required by the larger diameter fan. The resultant JT8D-100 engine models have the following characteristics at take-off thrust, compared to the current JT8D engine: Airflow and bypass ratio are increased, and fan pressure ratio and engine speed are reduced. The resultant engine is also longer, larger in diameter, and heavier than the JT8D base model, but these latter changes are compensated by the increased thrust and decreased fuel comsumption of the modified engine, thus providing the capability for maintaining the performance of the current JT8D-powered aircraft.

  9. Eling-Oz formula for the holographic bulk viscosity

    NASA Astrophysics Data System (ADS)

    Buchel, Alex

    2011-05-01

    Recently Eling and Oz [1] proposed a simple formula for the bulk viscosity of holographic plasma. They argued that the formula is valid in the high temperature (near-conformal) regime, but is expected to break down at low temperatures. We point out that the formula is in perfect agreement with the previous computations of the bulk viscosity of the cascading plasma [2, 3], as well as with the previous computations of the bulk viscosity of {N} = {2^*} plasma [4, 5]. In the latter case it correctly reproduces the critical behaviour of the bulk viscosity in the vicinity of the critical point with the vanishing speed of sound.

  10. JT15D simulated flight data evaluation

    NASA Technical Reports Server (NTRS)

    Holm, R. G.

    1984-01-01

    The noise characteristics of the JT15D turbofan engine was analyzed with the objectives of: (1) assessing the state-of-art ability to simulate flight acoustic data using test results acquired in wind tunnel and outdoor (turbulence controlled) environments; and (2) predicting the farfield noise directivity of the blade passage frequency (BPF) tonal components using results from rotor blade mounted dynamic pressure instrumentation. Engine rotor tip speeds at subsonic, transonic, and supersonic conditions were evaluated. The ability to simulate flight results was generally within 2-3 dB for both outdoor and wind tunnel acoustic results. Some differences did occur in the broadband noise level and in the multiple-pure-tone harmonics at supersonic tip speeds. The prediction of blade passage frequency tone directivity from dynamic pressure measurements was accomplished for the three tip speed conditions. Predictions were made of the random and periodic components of the tone directivity. The technique for estimating the random tone component used hot wire data to establish a correlation between dynamic pressure and turbulence intensity. This prediction overestimated the tone level by typically 10 dB with the greatest overestimates occurring at supersonic conditions.

  11. JT-60 Upgrade vertical stability experiments and analysis

    NASA Astrophysics Data System (ADS)

    Humphreys, D. A.; Yoshino, Ryuji

    1992-05-01

    The JT-60 Upgrade tokamak (JT-60U), can produce plasmas with vertical elongation (kappa approximately = 1.6), and thus allows investigation of vertical instability phenomena. The present work describes investigation of the vertical stability characteristics of JT-60U plasmas through experimental results and simulation. Experiments described include feedback turnoff cases and high beta(sub p) unstable plasma cases. For purposes of simulation, the plasma is modeled as a rigid assembly of current-carrying axisymmetric loops. A nominal conductor model based on design geometry was modified to reproduce the results of a series of coil excitation experiments using a reduced order system identification approach. A two-coil model was used to fit the experimental coil excitation behavior, and the full order conductor model was modified to allow the dominant modes to reflect the low order dynamic response. The resulting plasma-conductor model is shown to reproduce the vertical stability behavior of JT-60U fairly well. Theoretical predictions of limits on the value of Shafranov (Lambda) achievable in JT-60U are made.

  12. Dynamic design of gas sorption J-T refrigerator

    NASA Technical Reports Server (NTRS)

    Chan, C. K.

    1986-01-01

    A long-life Joule-Thomson refrigerator which is heat powered, involves no sealing, and has few mechanical parts is desirable for long-term sensor cooling in space. In the gas-sorption J-T refrigerator, cooling is achieved by gas sorption (either adsorption or absorption) processes. Currently, a modular, single-stage refrigerator is being designed and built to be operated at 20 K. The design was analyzed using a dynamic model, which is described here. The model includes the kinetics of the compressors and the heat switches, the heat transfer of the pre-coolers and the heat exchangers, the on/off ratio of the check valves, and the impedance of the J-T valve. The cooling power, the cycle time, and the operating conditions were obtained in terms of the power input, the heat sink temperature, and the J-T impedance.

  13. Performance of JT-60SA divertor Thomson scattering diagnostics

    SciTech Connect

    Kajita, Shin; Hatae, Takaki; Tojo, Hiroshi; Hamano, Takashi; Shimizu, Katsuhiro; Kawashima, Hisato; Enokuchi, Akito

    2015-08-15

    For the satellite tokamak JT-60 Super Advanced (JT-60SA), a divertor Thomson scattering measurement system is planning to be installed. In this study, we improved the design of the collection optics based on the previous one, in which it was found that the solid angle of the collection optics became very small, mainly because of poor accessibility to the measurement region. By improvement, the solid angle was increased by up to approximately five times. To accurately assess the measurement performance, background noise was assessed using the plasma parameters in two typical discharges in JT-60SA calculated from the SONIC code. Moreover, the influence of the reflection of bremsstrahlung radiation by the wall is simulated by using a ray tracing simulation. The errors in the temperature and the density are assessed based on the simulation results for three typical field of views.

  14. MIXING STUDY FOR JT-71/72 TANKS

    SciTech Connect

    Lee, S.

    2013-11-26

    All modeling calculations for the mixing operations of miscible fluids contained in HBLine tanks, JT-71/72, were performed by taking a three-dimensional Computational Fluid Dynamics (CFD) approach. The CFD modeling results were benchmarked against the literature results and the previous SRNL test results to validate the model. Final performance calculations were performed by using the validated model to quantify the mixing time for the HB-Line tanks. The mixing study results for the JT-71/72 tanks show that, for the cases modeled, the mixing time required for blending of the tank contents is no more than 35 minutes, which is well below 2.5 hours of recirculation pump operation. Therefore, the results demonstrate the adequacy of 2.5 hours’ mixing time of the tank contents by one recirculation pump to get well mixed.

  15. Cryogenic requirements for the JT-60SA Tokamak

    NASA Astrophysics Data System (ADS)

    Michel, Frederic; Hitz, D.; Hoa, Christine; Lamaison, Valerie; Kamiya, Koji; Roussel, Pascal; Wanner, Manfred; Yoshida, Kiyoshi

    2012-06-01

    The superconducting tokamak JT-60SA is part of the Broader Approach Programmeagreed between Japan and Europe. CEA is in charge of the cryogenic system procurementincluding the Warm Compression Station, the gas storages, the Refrigerator Cold Box andthe Auxiliary Cold Box (ACB) which has to be installed on the JAEA Naka site in 2016.This paper summarizes the updated cryogenic requirements for the tokamak JT-60SAcryogenic system. The cryogenic system has a refrigeration capacity of about 9 kW equivalent at 4.5K, to supply cryopump panels at 3.7 K, superconducting magnets and cold structures at 4.4 K, HTS current leads at 50 K, and thermal shields at 80 K. This paper presents the static and variable heat loads of the different cooling loops and the results of the rmohydraulic calculations to derive the transient heat loads at the interface between the magnet system cooling loops and the Auxiliary Cold Box.

  16. JT9D ceramic outer air seal system refinement program

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1982-01-01

    The abradability and durability characteristics of the plasma sprayed system were improved by refinement and optimization of the plasma spray process and the metal substrate design. The acceptability of the final seal system for engine testing was demonstrated by an extensive rig test program which included thermal shock tolerance, thermal gradient, thermal cycle, erosion, and abradability tests. An interim seal system design was also subjected to 2500 endurance test cycles in a JT9D-7 engine.

  17. The 727/JT8D refan side nacelle airloads

    NASA Technical Reports Server (NTRS)

    Bailey, R. W.; Vadset, H. J.

    1974-01-01

    Airloads on the 727/JT8D refan side engine nacelle are presented. These consist of surface static pressure distributions from two low speed wind tunnel tests. External nacelle surface pressures are from testing of a flow-through, body mounted nacelle model, and internal inlet surface pressures are from performance testing of a forced air inlet model. The method for obtaining critical airloads on nacelle components and a representative example are discussed.

  18. Results of acoustic testing of the JT8D-109 refan engines

    NASA Technical Reports Server (NTRS)

    Burdsall, E. A.; Brochu, F. P.; Scaramella, V. M.

    1975-01-01

    A JT8D engine was modified to reduce jet noise levels by 6-8 PNdB at takeoff power without increasing fan generated noise levels. Designated the JT8D-109, the modified engines featured a larger single stage fan, and acoustic treatment in the fan discharge ducts. Noise levels were measured on an outdoor test facility for eight engine/acoustic treatment configurations. Compared to the baseline JT8D, the fully treated JT8D-109 showed reductions of 6 PNdB at takeoff, and 11 PNdB at a typical approach power setting.

  19. Present status and future prospects of the JT-60SA project

    NASA Astrophysics Data System (ADS)

    Ishida, S.; Barabaschi, P.; Kamada, Y.

    2014-10-01

    The JT-60SA project has been implemented jointly by Europe and Japan since June 2007. After the disassembly of JT-60 from the torus hall had been completed in October 2012, the project achieved the major milestone of starting the tokamak's assembly at the JAEA Naka site in January 2013 following the completion of the cryostat base in Europe and its transport to Japan. Procurement and assembly activities for components such as the superconducting magnet, cryogenic system, power supply, vacuum vessel, divertor and cryostat are progressing on track towards the start of operation in March 2019. In preparation for exploitation, the JT-60SA Research Plan was issued in December 2011, and the research integration activities are addressing JT-60SA data management, validation and analysis tools. This paper overviews the latest evolution of the project in terms of construction and exploitation for JT-60SA.

  20. Development of a J-T Micro Compressor

    NASA Astrophysics Data System (ADS)

    Champagne, P.; Olson, J. R.; Nast, T.; Roth, E.; Collaco, A.; Kaldas, G.; Saito, E.; Loung, V.

    2015-12-01

    Lockheed Martin has developed and tested a space-quality compressor capable of delivering closed-loop gas flow with a high pressure ratio, suitable for driving a Joule- Thomson cold head. The compressor is based on a traditional “Oxford style” dual-opposed piston compressor with linear drive motors and flexure-bearing clearance-seal technology for high reliability and long life. This J-T compressor retains the approximate size, weight, and cost of the ultra-compact, 200 gram Lockheed Martin Pulse Tube Micro Compressor, despite the addition of a flow-rectifying system to convert the AC pressure wave into a steady flow.

  1. Improvement of JT-60U Negative Ion Source Performance

    SciTech Connect

    L.R. Grisham; M. Kuriyama; M. Kawai; T. Itoh; N. Umeda; JT-60U Team

    2000-11-15

    The negative ion neutral beam system now operating on JT-60U was the first application of negative ion technology to the production of beams of high current and power for conversion to neutral beams, and has successfully demonstrated the feasibility of negative ion beam heating systems for ITER and future tokamak reactors [1, 2]. It also demonstrated significant electron heating[3] and high current drive efficiency in JT-60U[4]. Because this was such a large advance in the state of the art with respect to all system parameters, many new physical processes appeared during the earlier phases of the beam injection experiments. We have explored the physical mechanisms responsible for these processes, and implemented solutions for some of them, in particular excessive beam stripping, the secular dependence of the arc and beam parameters, and nonuniformity of the plasma illuminating the beam extraction grid. This has reduced the percentage of beam heat loading on the downstream grids by roug hly a third, and permitted longer beam pulses at higher powers. Progress is being made in improving the negative ion current density, and in coping with the sensitivity of the cesium in the ion sources to oxidation by tiny air or water leaks, and the cathode operation is being altered.

  2. Scale model testing of the jet noise characteristics of the JT8D refan engine nozzle system

    NASA Technical Reports Server (NTRS)

    Reed, D. H.

    1974-01-01

    The results are presented of static scale model acoustic tests of the nozzle system for the JT8D-9 baseline engine and candidate nozzle systems for JT8D-109, JT8D-115, and JT8D-117 refan engines. The objective of these tests was to determine the jet noise benefit of the three refan engine cycles relative to the baseline JT8D-9, and to provide acoustic information toward selection of the optimum primary-secondary area match and centerbody contour for the refan engine cycles. One of the nozzle configurations was tested with and without simulated turbine exit swirl to determine what effect, if any, swirl has no jet noise. The JT8D-109 cycle was found to afford approximately 9 db (0ASPL) jet noise reduction relative to the JT8D-9 when compared on an equal static thrust basis. The JT8D-115 and JT8D-117 afford an 8 db and 6 db reduction, respectively, relative to the JT8D-9, at equal static thrust. Turbine exit swirl was found to have no significant effect on the jet noise of the JT8D-109 nozzle system.

  3. Performance Study on ST/JT Hybrid Cryocoolers Working at Liquid Helium Temperature

    NASA Astrophysics Data System (ADS)

    Dongli, Liu; Xuan, Tao; Xiao, Sun; Zhihua, Gan

    The ST/JT hybridcryocooler consists of a Stirling-typecryocooler and a J-T loop. The common process of steady-state operation is given. Pressure-Enthalpy map analysis and thermodynamic calculation showhow the precooling temperature, high pressure and recuperator effectiveness affect thecooling powerat liquid helium temperature. Applying the current performance level of the Stirling cooler,the overall COP of the hybrid cryocooleris roughly optimized. This performance study shows that the hybrid cryocooler can develop its performance potential with improved J-T compressors with larger pressure ratio and aprecooler working at lower temperature.

  4. Status of the JT8D refan noise reduction program

    NASA Technical Reports Server (NTRS)

    Kester, J. D.

    1974-01-01

    The present work describes measures being taken to suppress jet noise in the JT8D engine and reports on some preliminary acoustic tests to evaluate noise characteristics of the engine. To reduce noise generation without sacrificing other essential engine performance or durability characteristics, the two stage fan will be replaced by a larger-diameter single stage fan. Refanned engines have an increased bypass ratio that contributes to the reduction of jet exhaust noise. Advanced acoustical design features will be incorporated in the larger, single-stage fan, and acoustic treatment will be incorporated in both the engine and the nacelle. First tests have shown that engine component noise levels are about as predicted and the acoustic treatment sections tested to date are providing predicted levels of attenuation. Further work is required to demonstrate engine performance goals and compatibility with 727 and DC-9 installations.

  5. JT8D high pressure compressor performance improvement

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1981-01-01

    An improved performance high pressure compressor with potential application to all models of the JT8D engine was designed. The concept consisted of a trenched abradable rubstrip which mates with the blade tips for each of the even rotor stages. This feature allows tip clearances to be set so blade tips run at or near the optimum radius relative to the flowpath wall, without the danger of damaging the blades during transients and maneuvers. The improved compressor demonstrated thrust specific fuel consumption and exhaust gas temperature improvements of 1.0 percent and at least 10 C over the takeoff and climb power range at sea level static conditions, compared to a bill-of-material high pressure compressor. Surge margin also improved 4 percentage points over the high power operating range. A thrust specific fuel consumption improvement of 0.7 percent at typical cruise conditions was calculated based on the sea level test results.

  6. Comparison of transient electron heat transport in LHD helical and JT-60U tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Inagaki, S.; Takenaga, H.; Ida, K.; Isayama, A.; Tamura, N.; Takizuka, T.; Shimozuma, T.; Kamada, Y.; Kubo, S.; Miura, Y.; Nagayama, Y.; Kawahata, K.; Sudo, S.; Ohkubo, K.; LHD Experimental Group; JT-60 Team

    2006-01-01

    Transient transport experiments are performed in plasmas with and without internal transport barriers (ITB) on LHD and JT-60U. The dependence of χe on the electron temperature, Te, and on the electron temperature gradient, ∇Te, is analysed with an empirical non-linear heat transport model. In plasmas without an ITB, two different types of non-linearity of the electron heat transport are observed from cold/heat pulse propagation: the χe depends on Te and ∇Te in JT-60U, while the ∇Te dependence is weak in LHD. Inside the ITB region, there is none or weak ∇Te dependence both in LHD and JT-60U. Growth of the cold pulse driven by the negative Te dependence of χe is observed inside the ITB region (LHD) and near the boundary of the ITB region (JT-60U).

  7. Lipoproteins binding malachite green to slow the decolorization of malachite green in Pseudomonas sp. JT-1.

    PubMed

    Wu, Jun; Li, Liguan; Du, Hongwei; Jiang, Lijuan; Zhang, Qiong; Wei, Zhongbo; Wang, Xiaolin; Xiao, Lin; Yang, Liuyan

    2011-01-01

    Lipoproteins of a malachite green (MG)-decolorizing bacterium Pseudomonas sp. JT-1 could bind MG to form green MG-Lipoproteins complexes, which prevented the decolorization of MG by triphenylmethane reductase.

  8. Development of New Cooling System Using Gm/jt Cryocoolers for the SKS Magnet

    NASA Astrophysics Data System (ADS)

    Aoki, K.; Haruyama, T.; Makida, Y.; Araoka, O.; Kasami, K.; Takahashi, T.; Nagae, T.; Kakiguchi, Y.; Sekimoto, M.; Tosaka, T.; Miyazaki, H.; Kuriyama, T.; Ono, M.; Orikasa, T.; Tsuchihashi, T.; Hirata, Y.

    2008-03-01

    We plan to develop a new improved cooling system for the Superconducting Kaon Spectrometer (SKS) magnet and transfer the magnet to the K1.8 beamline of the Hadron Hall of the Japan Proton Accelerator Research Complex (J-PARC) for further use in nuclear physics experiments. To replace the present 300 W cryogenic system, we will adopt a new cooling method that uses 4 K Gifford-McMahon/Joule-Thomson (GM/JT) cryocoolers. In order to decide a practical design for the new liquid helium reservoir of the magnet, which will be equipped with GM/JT cryocoolers, cooling tests on a GM/JT cryocooler were performed from February to March 2007. We constructed a new cooling test stand with a GM/JT cryocooler and measured the cooling capacities under several thermal shield temperatures with or without a baffle, which helped prevent convection. Based on the test results, we have finally decided to adopt three GM/JT cryocoolers for the new SKS along with a baffle and an additional dedicated GM cooler to cool the thermal shield of the GM/JT ports.

  9. A 727/JT8D-100 series engine exhaust system propulsion performance model test

    NASA Technical Reports Server (NTRS)

    Haugan, W. J.; Kern, P. R. A.

    1974-01-01

    The results are presented from testing one-eighth scale models of the Pratt and Whitney aircraft reference and Boeing nozzles for the JT8D-100 series mixed flow engines. The objective of the test was to obtain the nozzle velocity and flow coefficients for the reference configurations and compare these with the Boeing configurations which incorporated a longer splitter between the fan and primary flows. A further comparison was made between the JT8D-100 series nozzles and the Boeing JT8D-9/727 production nozzle performance. A statistical analysis was used to compare configurations which showed the performance (velocity coefficient) of the reference and the Boeing configuration was the same for the JT8D-109. It also showed no difference between reference and the Boeing configuration for the JT8D-115 and no difference for the JT8D-117 nozzles. Bypass ratio (match) was shown to be equally dependent on splitter position as on nozzle area within the range investigated. The nozzles were very similar in flow coefficient within an engine family. Excellent profile data was recorded. The effects of swirl on the nozzle performance was examined and found to degrade the velocity and flow coefficients.

  10. Program for refan JT8D engine design, fabrication and test, phase 2

    NASA Technical Reports Server (NTRS)

    Glass, J. A.; Zimmerman, E. S.; Scaramella, V. M.

    1975-01-01

    The objective of the JT8D refan program was to design, fabricate, and test certifiable modifications of the JT8D engine which would reduce noise generated by JT8D powered aircraft. This was to be accomplished without affecting reliability and maintainability, at minimum retrofit cost, and with no performance penalty. The mechanical design, engine performance and stability characteristics at sea-level and altitude, and the engine noise characteristics of the test engines are documented. Results confirmed the structural integrity of the JT8D-109. Engine operation was stable throughout the airplane flight envelope. Fuel consumption of the test engines was higher than that required to meet the goal of no airplane performance penalty, but the causes were identified and corrected during a normal pre-certification engine development program. Compared to the baseline JT8D-109 engine, the acoustically treated JT8D-109 engine showed noise reductions of 6 PNdB at takeoff and 11 PNdB at a typical approach power setting.

  11. Transient simulation of a miniature Joule-Thomson (J-T) cryocooler with and without the distributed J-T effect

    NASA Astrophysics Data System (ADS)

    Damle, R. M.; Atrey, M. D.

    2015-01-01

    The aim of this work is to develop a transient program for the simulation of a miniature Joule-Thomson (J-T) cryocooler to predict its cool-down characteristics. A one dimensional transient model is formulated for the fluid streams and the solid elements of the recuperative heat exchanger. Variation of physical properties due to pressure and temperature is considered. In addition to the J-T expansion at the end of the finned tube, the distributed J-T effect along its length is also considered. It is observed that the distributed J-T effect leads to additional cooling of the gas in the finned tube and that it cannot be neglected when the pressure drop along the length of the finned tube is large. The mathematical model, method of resolution and the global transient algorithm, within a modular object-oriented framework, are detailed in this paper. As a part of verification and validation of the developed model, cases available in the literature are simulated and the results are compared with the corresponding numerical and experimental data.

  12. The JT9D Jet Engine Diagnostics Program

    NASA Technical Reports Server (NTRS)

    Olsson, W. J.

    1982-01-01

    The various engine deterioration phenomena that affect JT9D performance retention were studied, and approaches to improve performance retention of engines were identified. The program included surveys of historical data, monitoring of in service engines, ground and flight testing of instrumented engines, analysis, and analytical modeling. Performance deterioration is made up of both short and long term modes, both of which are flight cycle related phenomena. Short term deterioration occurs primarily during airplane acceptance testing prior to delivery to the airline. This effect is caused by flight load and power induced clearance closures and engine deflections with resulting rubbing of airfoils and seals. Long term deterioration is caused by erosion of airfoils and gas path seals during ground operation and take off and by cyclic induced thermal distortion of the high pressure turbine airfoils. Studies of possible remedial approaches have shown that performance retention within 1 to 2 percent of initial revenue service performance can be achieved with a proper program of hot section and cold section maintenance.

  13. Oxygen chemisorption compressor study for cryogenic J-T refrigeration

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Blue, Gary D.

    1987-01-01

    Over twenty potentially reversible heat-powered oxide reactions have been studied and/or tested to determine their potential use as thermochemical oxygen compressors for cryogenic J-T LO2 refrigerators. One gas-solid compound family, Pr(1-n)Ce(n)O(x), proved to be completely reversible with fast kinetics for all pressure ranges tested below 650 C. With a heat-powered charcoal/methane physical adsorption upper stage and a Pr(1-n)Ce(n)O(x) chemisorption lower stage, temperatures should be attainable in the 55-80 K range for less power and over five times less weight than for charcoal/nitrogen sorption refrigeration systems. Total system power requirements with a hydride chemisorption lower stage (10 K to 7 K minimum) are about three times less than any mechanical refrigerator, and spacecraft refrigeration weights are about twenty times less. Due to the lack of wear-related moving parts in sorption refrigerators, life expectancy is at least ten years, and there essentially no vibration.

  14. Cryogenic thermometry for refrigerant distribution system of JT-60SA

    NASA Astrophysics Data System (ADS)

    Natsume, K.; Murakami, H.; Kizu, K.; Yoshida, K.; Koide, Y.

    2015-12-01

    JT-60SA is a fully superconducting fusion experimental device involving Japan and Europe. The cryogenic system supplies supercritical or gaseous helium to superconducting coils through valve boxes or coil terminal boxes and in-cryostat pipes. There are 86 temperature measurement points at 4 K along the distribution line. Resistance temperature sensors will be installed on cooling pipes in vacuum. In this work, two sensor attachment methods, two types of sensor, two thermal anchoring methods, and two sensor fixation materials have been experimentally evaluated in terms of accuracy and mass productivity. Finally, the verification test of thermometry has been conducted using the sample pipe fabricated in the same way to the production version, which has been decided by the comparison experiments. The TVO sensor is attached by the saddle method with Apiezon N grease and the measurement wires made of phosphor bronze are wound on the pipe with Stycast 2850FT as the thermal anchoring. A Cernox sensor is directly immersed in liquid helium as a reference thermometer during the experiment. The measured temperature difference between the attached one and reference one has been within ±15 mK in the range of 3.40-4.73 K. It has satisfies the accuracy requirement of 0.1 K.

  15. 2-Naphthoate catabolic pathway in Burkholderia strain JT 1500.

    PubMed

    Morawski, B; Eaton, R W; Rossiter, J T; Guoping, S; Griengl, H; Ribbons, D W

    1997-01-01

    Burkholderia strain (JT 1500), able to use 2-naphthoate as the sole source of carbon, was isolated from soil. On the basis of growth characteristics, oxygen uptake experiments, enzyme assays, and detection of intermediates, a degradation pathway of 2-naphthoate is proposed. The features of this pathway are convergent with those for phenanthrene. We propose a pathway for the conversion of 2-naphthoate to 1 mol (each) of pyruvate, succinate, and acetyl coenzyme A and 2 mol of CO2. During growth in the presence of 2-naphthoate, six metabolites were detected by thin-layer chromatography, high-performance liquid chromatography, and spectroscopy. 1-Hydroxy-2-naphthoate accumulated in the culture broth during growth on 2-naphthoate. Also, the formation of 2'-carboxybenzalpyruvate, phthalaldehydate, phthalate, protocatechuate, and beta-carboxy-cis,cis-muconic acid was demonstrated. (1R,2S)-cis-1,2-Dihydro-1,2-dihydroxy-2-naphthoate was thus considered an intermediate between 2-naphthoate and 1-hydroxy-2-naphthoate, but it was not transformed by whole cells or their extracts. We conclude that this diol is not responsible for the formation of 1-hydroxy-2-naphthoate from 2-naphthoate but that one of the other three diastereomers is not eliminated as a potential intermediate for a dehydration reaction.

  16. B747/JT9D flight loads and their effect on engine running clearances and performance deterioration; BCAC NAIL/P and WA JT9D engine diagnostics programs

    NASA Technical Reports Server (NTRS)

    Olsson, W. J.; Martin, R. L.

    1982-01-01

    Flight loads on the 747 propulsion system and resulting JT9D blade to outer airseal running clearances during representative acceptance flight and revenue flight sequences were measured. The resulting rub induced clearance changes, and engine performance changes were then analyzed to validate and refine the JT9D-7A short term performance deterioration model.

  17. Performance analysis of a miniature Joule-Thomson cryocooler with and without the distributed J-T effect

    NASA Astrophysics Data System (ADS)

    Damle, Rashmin; Atrey, Milind

    2015-12-01

    Cryogenic temperatures are obtained with Joule-Thomson (J-T) cryocoolers in an easier way as compared to other cooling techniques. Miniature J-T cryocoolers are often employed for cooling of infrared sensors, cryoprobes, biological samples, etc. A typical miniature J-T cryocooler consists of a storage reservoir/compressor providing the high pressure gas, a finned tube recuperative heat exchanger, an expansion valve/orifice, and the cold end. The recuperative heat exchanger is indispensable for attaining cryogenic temperatures. The geometrical parameters and the operating conditions of the heat exchanger drastically affect the cryocooler performance in terms of cool down time and cooling effect. In the literature, the numerical models for the finned recuperative heat exchanger have neglected the distributed J-T effect. The distributed J-T effect accounts for the changes in enthalpy of the fluid due to changes of pressure in addition to those due to changes of temperature. The objective of this work is to explore the distributed J-T effect and study the performance of a miniature J-T cryocooler with and without the distributed J-T effect. A one dimensional transient model is employed for the numerical analysis of the cryocooler. Cases with different operating conditions are worked out with argon and nitrogen as working fluids.

  18. Atomization and combustion characteristics of antimisting fuels using JT8D and air-boost injectors

    NASA Technical Reports Server (NTRS)

    Kennedy, J. B.; Florentino, A. J.

    1986-01-01

    The atomization levels of antimisting fuels are presently determined for a JT8D fuel injector, a low emission airblast JT8D injector, and an air-boost injector, at operating conditions simulating engine operating conditions. The effects of the use of antimisting kerosene (AMK) on component performance are also studied in the case of an in-service JT8D engine. The use of the AMK fuel causes a decline in the quality of the spray, most notably as a large increase in the Sauter mean diameter for all three injector types. In addition, the idle patternation data obtained indicate that the low emission injector fuel distribution changed from a hollow cone Jet A spray having no fuel at its center to a semihollow spray cone in the case of AMK; this change could disrupt the combustor primary zone recirculation pattern.

  19. VME and network applications for the JT-60U control system

    NASA Astrophysics Data System (ADS)

    Kimura, T.

    1994-12-01

    The control system for the large tokamak JT-60 at JAERI-Naka was completed in 1985. It was originally composed of 16-bit industrial minicomputers and CAMAC systems with 16-bit microcomputers. Rejuvenation of the control system has become necessary to improving the control performance. The renewal of the control system is also stimulated by the requirements for upgrading the software development and hardware maintenance environment of the control system. This paper describes how the control system was and will be upgraded, utilizing the advanced technologies of VME and networks. Two years ago, a VMEbus-based 32-bit multiprocessor system for fast plasma control and a new operator's console using UNIX workstations connected to an Ethernet LAN were developed to cope with upgrading the JT-60 tokamak (JT-60U). VME and network applications are now being extended to the level of subsystem controllers.

  20. Pollution reduction technology program for class T4(JT8D) engines

    NASA Technical Reports Server (NTRS)

    Roberts, R.; Fiorentino, A. J.; Diehl, L. A.

    1977-01-01

    The technology required to develop commercial gas turbine engines with reduced exhaust emissions was demonstrated. Can-annular combustor systems for the JT8D engine family (EPA class T4) were investigated. The JT8D turbofan engine is an axial-flow, dual-spool, moderate-bypass-ratio design. It has a two-stage fan, a four-stage low-pressure compressor driven by a three-stage low-pressure turbine, and a seven-stage high-pressure compressor driven by a single-stage high-pressure turbine. A cross section of the JT8D-17 showing the mechanical configuration is given. Key specifications for this engine are listed.

  1. Summary and analysis of performance and stability characteristics of the refan JT8D-109 engine

    NASA Technical Reports Server (NTRS)

    Sanberg, K. G.; Mogielnicki, R. M.; Davis, J. C.; Scaramella, V. M.

    1975-01-01

    The refan JT8D-109 performance and stability characteristics are reported as determined from sea level testing, altitude testing, and DC-9 flight testing. The test results are summarized as follows: (1) TSFC at SLS achieved design goal of 12.66 percent reduction. (2) TSFC at altitude average cruise power 0.5 percent higher than design goal, (3) TSFC at altitude maximum cruise power 1.7-3.7 percent higher than design goal, (4) ground starting consistent with JT8D-9 base engine, (5) successful flight starts without starter assist, (6) transient surge margin equivalent to JT8D-9, (7) stable engine operation with inlet distortion, and (8) stable engine operation during snap acceleration and deceleration. A flight idle setting is required for acceptable aborted-landing go-around acceleration time due to increase in low-rotor moment of inertia, and a performance improvement program should be conducted as part of any future certification program.

  2. Minimization of Reactive Power Fluctuation in JT-60SA Magnet Power Supply

    NASA Astrophysics Data System (ADS)

    Shimada, K.; Terakado, T.; Yamauchi, K.; Matsukawa, M.; Baulaigue, O.; Coletti, R.; Coletti, A.; Novello, L.

    2013-02-01

    This paper describes an asymmetric control method for the firing angle and a start/stop timing shift control of four thyristor converters called “Booster PS" to minimize the reactive power fluctuation during plasma initiation in JT-60SA. From the simulation using the “PSCAD/EMTDC" code, it is found that these control methods can drastically reduce the reactive power induced by the four units of the “Booster PS". In addition, the voltage fluctuation of the motor-generator connected to the “Booster PS" is expected to be suppressed. This can also contribute to achieve stable control of the JT-60SA magnet power supplies.

  3. JT-60 configuration parameters for feedback control determined by regression analysis

    NASA Astrophysics Data System (ADS)

    Matsukawa, Makoto; Hosogane, Nobuyuki; Ninomiya, Hiromasa

    1991-12-01

    The stepwise regression procedure was applied to obtain measurement formulas for equilibrium parameters used in the feedback control of JT-60. This procedure automatically selects variables necessary for the measurements, and selects a set of variables which are not likely to be picked up by physical considerations. Regression equations with stable and small multicollinearity were obtained and it was experimentally confirmed that the measurement formulas obtained through this procedure were accurate enough to be applicable to the feedback control of plasma configurations in JT-60.

  4. 76 FR 72130 - Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... result in an uncontained engine failure and damage to the airplane. Actions Since Existing AD (72 FR..., -7H, -7J, -20, and -20J engines; Adding ECIs for web cooling holes and tierod holes in HPT stage 2 disks installed in JT9D-59A and -70A engines; Adding ECIs for web cooling holes and tierod holes in...

  5. DC-9 flight demonstration program with refanned JT8D engines. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The design, analysis, fabrication, and ground and flight testing of DC-9 airframe/nacelle hardware with prototype JT8D-109 engines are discussed. The installation of the JT8D-109 engine on the DC-9 Refan airplane required new or modified hardware for the pylon, nacelle, and fuselage. The acoustic material used in the nose cowl was bonded aluminum honeycomb sandwich and the exhaust duct acoustic material was Inconel 625 Stresskin. The sea level static, standard day bare engine takeoff thrust, the cruise TSFC and the maximum available cruise thrust for the JT8D-109 engine were compared with those of the JT8D-9 engine. The range capabilities of the DC-9 Refan and the production DC-9 airplane were also compared. The Refan airplane demonstrated flight characteristics similar to the production DC-9-30 and satisfied airworthiness requirements. Flyover noise levels were determined for the DC-9 Refan and the DC-9 C-9A airplane for takeoff and landing conditions. Cost estimates were also made.

  6. Plasma Physics found in JT-60 Tokamak over the Last 20 years

    SciTech Connect

    Kikuchi, M.

    2009-07-07

    This paper summarizes major plasma physics obtained during the period of JT-60 operation for 23 years with special emphasis on research towards steady-state operation of tokamak. Topics included are observation of large bootstrap current fraction, negative shear scenario, demonstration of efficient beam and EC current drive, discovery of current hole, stabilization of the RWM, discovery of ITB (internal transport barrier).

  7. ASASSN-16jt and pre-outburst transient AT 2016cvk resemble the unusual transient SN 2009ip

    NASA Astrophysics Data System (ADS)

    Brown, J. S.; Prieto, J. L.; Shappee, B. J.; Dong, Subo; Morrell, N.; Stanek, K. Z.; Holoien, T. W.-S.; Kochanek, C. S.; Shields, J.; Bersier, D.; Bose, S.; Chen, Ping; Brimacombe, J.; Marples, P.

    2016-09-01

    In ATEL #9439 we reported the discovery of a new transient source, ASASSN-16jt, and note its proximity to a previously reported transient (AT 2016cvk). Based on the coordinates in the two reportings, the two sources appeared to be separated by ~1". However, based on archival LCOGT imaging of AT 2016cvk, we find that the position of the two sources may in fact be coincident, strongly indicating that AT 2016cvk was a prior outburst of ASASSN-16jt.

  8. G1/ELE Functions in the Development of Rice Lemmas in Addition to Determining Identities of Empty Glumes

    PubMed Central

    Liu, Mengjia; Li, Haifeng; Su, Yali; Li, Wenqiang; Shi, Chunhai

    2016-01-01

    Rice empty glumes, also named sterile lemmas or rudimentary lemmas according to different interpretations, are distinct from lemmas in morphology and cellular pattern. Consistently, the molecular mechanism to control the development of lemmas is different from that of empty glumes. Rice LEAFY HULL STERILE1(OsLHS1) and DROOPING LEAF(DL) regulate the cellular pattern and the number of vascular bundles of lemmas respectively, while LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE) and PANICLE PHYTOMER2 (PAP2)/OsMADS34 determine identities of empty glumes. Though some progress has been made, identities of empty glumes remain unclear, and genetic interactions between lemma genes and glume genes have been rarely elucidated. In this research, a new G1/ELE mutant g1–6 was identified and the phenotype was analyzed. Similar to previously reported mutant lines of G1/ELE, empty glumes of g1–6 plants transform into lemma-like organs. Furthermore, Phenotypes of single and double mutant plants suggest that, in addition to their previously described gene-specific functions, G1/ELE and OsLHS1 play redundant roles in controlling vascular bundle number, cell volume, and cell layer number of empty glumes and lemmas. Meanwhile, expression patterns of G1/ELE in osmads1-z flowers and OsLHS1 in g1–6 flowers indicate they do not regulate each other at the level of transcription. Finally, down-regulation of the empty glume gene OsMADS34/PAP2 and ectopic expression of the lemma gene DL, in the g1–6 plants provide further evidence that empty glumes are sterile lemmas. Generally, our findings provided valuable information for better understanding functions of G1 and OsLHS1 in flower development and identities of empty glumes. PMID:27462334

  9. G1/ELE Functions in the Development of Rice Lemmas in Addition to Determining Identities of Empty Glumes.

    PubMed

    Liu, Mengjia; Li, Haifeng; Su, Yali; Li, Wenqiang; Shi, Chunhai

    2016-01-01

    Rice empty glumes, also named sterile lemmas or rudimentary lemmas according to different interpretations, are distinct from lemmas in morphology and cellular pattern. Consistently, the molecular mechanism to control the development of lemmas is different from that of empty glumes. Rice LEAFY HULL STERILE1(OsLHS1) and DROOPING LEAF(DL) regulate the cellular pattern and the number of vascular bundles of lemmas respectively, while LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE) and PANICLE PHYTOMER2 (PAP2)/OsMADS34 determine identities of empty glumes. Though some progress has been made, identities of empty glumes remain unclear, and genetic interactions between lemma genes and glume genes have been rarely elucidated. In this research, a new G1/ELE mutant g1-6 was identified and the phenotype was analyzed. Similar to previously reported mutant lines of G1/ELE, empty glumes of g1-6 plants transform into lemma-like organs. Furthermore, Phenotypes of single and double mutant plants suggest that, in addition to their previously described gene-specific functions, G1/ELE and OsLHS1 play redundant roles in controlling vascular bundle number, cell volume, and cell layer number of empty glumes and lemmas. Meanwhile, expression patterns of G1/ELE in osmads1-z flowers and OsLHS1 in g1-6 flowers indicate they do not regulate each other at the level of transcription. Finally, down-regulation of the empty glume gene OsMADS34/PAP2 and ectopic expression of the lemma gene DL, in the g1-6 plants provide further evidence that empty glumes are sterile lemmas. Generally, our findings provided valuable information for better understanding functions of G1 and OsLHS1 in flower development and identities of empty glumes. PMID:27462334

  10. Engine component improvement: Performance improvement, JT9D-7 3.8 AR fan

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1980-01-01

    A redesigned, fuel efficient fan for the JT9D-7 engine was tested. Tests were conducted to determine the effect of the 3.8 AR fan on performance, stability, operational characteristics, and noise of the JT9D-7 engine relative to the current 4.6 AR Bill-of-Material fan. The 3.8 AR fan provides increased fan efficiency due to a more advanced blade airfoil with increased chord, eliminating one part span shroud and reducing the number of fan blades and fan exit guide vanes. Engine testing at simulated cruise conditions demonstrated the predicted 1.3 percent improvement in specific fuel consumption with the redesigned 3.8 AR fan. Flight testing and sea level stand engine testing demonstrated exhaust gas temperature margins, fan and low pressure compressor stability, operational suitability, and noise levels comparable to the Bill-of-Material fan.

  11. Reduction of JT8D powered aircraft noise by engine refanning

    NASA Technical Reports Server (NTRS)

    Stitt, L. E.; Medeiros, A. A.

    1974-01-01

    The technical feasibility is described of substantially reducing the noise levels of existing JT8D powered aircraft by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles. No major technical problems exist that preclude the development and installation of refanned engines on aircraft currently powered by the JT8D engine. The refan concept is technically feasible and provides calculated noise reductions of from 7 to 8 EPNdb for the B727-200 aircraft and from 10 to 12 EPNdb for the DC-9-32 aircraft at the FAR Part 36 measuring stations. These noise levels are lower than both the FAR Part 36 noise standards and the noise levels of the wide-body DC-10-10. Corresponding reductions in the 90 EPNdb footprint area are estimated to vary from about 70 percent for the DC-9 to about 80 percent for the B727.

  12. Reduction of JT8D powered aircraft noise by engine refanning

    NASA Technical Reports Server (NTRS)

    Stitt, L. E.; Medeiros, A. A.

    1974-01-01

    The purpose of the Refan Program is to establish the technical feasibility of substantially reducing the noise levels of existing JT8D powered aircraft. This would be accomplished by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles. No major technical problems exist that preclude the development and installation of refanned engines on aircraft currently powered by the JT8D engine. The refan concept is technically feasible and provides calculated noise reductions of from 7 to 8 EPNdB for the B727-200 aircraft and from 10 to 12 EPNdB for the DC-9-32 aircraft at the FAR Part 36 measuring stations. Corresponding reductions in the 90 EPNdB footprint area are estimated to vary from about 70 percent for the DC-9 to about 80 percent for the B727.

  13. Finite element-integral acoustic simulation of JT15D turbofan engine

    NASA Astrophysics Data System (ADS)

    Baumeister, K. J.; Horowitz, S. J.

    1984-07-01

    An iterative finite element integral technique is used to predict the sound field radiated from the JT15D turbofan inlet. The sound field is divided into two regions: the sound field within and near the inlet which is computed using the finite element method and the radiation field beyond the inlet which is calculated using an integral solution technique. The velocity potential formulation of the acoustic wave equation was employed in the program. For some single mode JT15D data, the theory and experiment are in good agreement for the far field radiation pattern as well as suppressor attenuation. Also, the computer program is used to simulate flight effects that cannot be performed on a ground static test stand.

  14. Summary of TFTR (Tokamak Fusion Test Reactor) diagnostics, including JET (Joint European Torus) and JT-60

    SciTech Connect

    Hill, K.W.; Young, K.M.; Johnson, L.C.

    1990-05-01

    The diagnostic instrumentation on TFTR (Tokamak Fusion Test Reactor) and the specific properties of each diagnostic, i.e., number of channels, time resolution, wavelength range, etc., are summarized in tables, grouped according to the plasma parameter measured. For comparison, the equivalent diagnostic capabilities of JET (Joint European Torus) and the Japanese large tokamak, JT-60, as of late 1987 are also listed in the tables. Extensive references are given to publications on each instrument.

  15. Effect of time dependent flight loads on JT9D-7 performance deterioration

    NASA Technical Reports Server (NTRS)

    Jay, A.; Lewis, B. L.

    1979-01-01

    The results of a modal transient analysis of the engine/aircraft system are presented. The response of the JT9D to analytically simulated vertical gusts and landings was predicted using a NASTRAN finite element mathematical model of the JT9D/747 propulsion system. The NASTRAN finite element model of the propulsion system included engine structural models of the fan, low/high pressure compressors, diffuser/turbine cases, and high/low pressure rotors, as well as nacelle models of the inlet cowl, tailcone, and wing pylon. The analysis conducted predicts that an insignificant level of JT9D-7 performance deterioration would occur due to a typical vertical gust encounter or a typical revenue service landing. Analysis of a high sink rate landing with a heavy fuel load indicates the possibility of local wear, however, the lack of an accurate dynamic rotor/seal interference model precludes an accurate quantitative evaluation of performance change for this once-per-airframe-life event.

  16. Simulation of the Effect of Plasma Flows in DIII-D, JET, and JT-60U

    SciTech Connect

    Porter, G D; Rognlien, T D; Rensink, M E; Loarte, A; Asakura, N; Takenaga, H; Mathews, G

    2002-05-17

    The results of 2D fluid plasma simulations of the ion flow in the boundary plasma of DIII-D, JET, and JT-60U are reported. The model includes the effects of drifts and of impurity radiation using a multi-species model of intrinsic carbon impurities. Drift effects are important in determining the primary and impurity ion fluxes in the SOL and the private region, with ExB drifts dominant. Simulated parallel velocities are consistent with experimental measurement on the high field side of JT-60U, where the parallel flow is determined by ion sources. Simulated parallel velocities are significantly less than seen in experiment at the outer midplane of JT-60U, and at the top of JET where the flow is sensitive to poloidal variations of the turbulence driven transport, suggesting the velocity in these regions is determined by transport. Parallel flows are reversed by changing the direction of the ion VB drift relative to the X-point.

  17. Phase 2 program on ground test of refanned JT8D turbofan engines and nacelles for the 727 airplane. Volume 3: Ground tests

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The NASA Refan Program included full-scale performance and noise ground tests of both a current production (JT8D-15) and a refanned (JT8D-115) engine. A description of the two ground tests including detailed propulsion, noise, and structural test results is presented. The primary objectives of the total test program were comparison of JT8D-15 and JT8D-115 overall propulsion system performance and noise characteristics and determination of incremental component noise levels. Other objectives of the test program included: (1) determination of acoustic treatment effectiveness; (2) measurement of internal sound pressure levels; (3) measurement of inlet and exhaust hardware performance; (4) determination of center-engine surge margin; and (5) evaluation of certain structural characteristics associated with the 727 refan center-engine inlet duct and JT8D refan engine exhaust system. The JT8D-15 and -115 tests were conducted during September 1974 and January to March 1975, respectively. Analyses of the test data indicated that the JT8D-115, as compared to the JT8D-15, demonstrates a 12.5 percent to 13.2 percent reduction in static specific fuel consumption, and a reduction of 6 to 7 PNdB in a weighted average value of static tone corrected perceived noise level. Separated into noise components, a significant reduction was shown for the inlet fan, aft fan, exhaust duct flow, turbine, and jet noises. However, core noise was increased. Photographs of test stands and test equipment are shown.

  18. 75 FR 3217 - J&T Hydro Company; H. Dean Brooks and W. Bruce Cox; Notice of Application for Transfer of License...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission J&T Hydro Company; H. Dean Brooks and W. Bruce Cox; Notice of Application... 30, 2009, J&T Hydro Company (transferor) and W. Dean Brooks, and H. Bruce Cox (transferees) filed...

  19. Assessment of QT and JT Intervals in Patients With Left Bundle Branch Block

    PubMed Central

    Tabatabaei, Peyman; Keikhavani, Ala; Haghjoo, Majid; Fazelifar, Amirfarjam; Emkanjoo, Zahra; Zeighami, Mahbobeh; Bakhshandeh, Hooman; Ghadrdoost, Behshid; Alizadeh, Abolfath

    2016-01-01

    Background Prolongation of the QT interval is considered a risk factor for cardiac adverse events and mortality. Left bundle branch block (LBBB) lengthens the QT interval. The corrected QT interval (QTc) is most likely overestimated because its prolongation is caused by increases in depolarization duration and not in repolarization. Objectives In this study, we aimed to apply corrected JT interval (JTc) as an appropriate measure of ventricular repolarization for predicting QTc in a formula. Patients and Methods The study population consisted of 101 patients with sinus rhythm (SR) and narrow QRS complexes (< 120 milliseconds). All patients underwent electrophysiology studies or ablation. A diagnostic catheter was positioned in the right ventricular apex (RVA) to induce LBBB at two different cycle lengths (CLs; 600 and 700 mv). The intrinsic QRS complex, QT time, and JT time were measured during SR and subsequent RVA pacing. The JTc was derived simply by subtracting the QRS duration from the QTc. Results Stimulation from the RVA increased the QTc from 456.20 ± 38.63 ms to 530.67 ± 47.73 ms at a CL of 600 (P < 0.0001) and to 502.32 ± 47.26 ms at 700 CL (P < 0.0001). JTc showed no significant changes with stimulation from the RVA (102.97 ± 11.35 ms vs. 103.59 ± 10.67 ms, P = 0.24). There was no significant correlation between JTc and QRS complex duration. A significant correlation was seen between QRS and QTc at both CLs. The ROC curve indicated that sensitivity of 80% and specificity of 67% were obtained with JTc duration of 92.6 ms. Conclusions Right ventricular pacing increases the QT interval without increasing the JT interval. Our results confirm that JTc, as an index of repolarization, is independent of ventricular depolarization. Therefore, it can be applied for predicting QTc in patients with LBBB. PMID:26949694

  20. JT8D-15/17 High Pressure Turbine Root Discharged Blade Performance Improvement. [engine design

    NASA Technical Reports Server (NTRS)

    Janus, A. S.

    1981-01-01

    The JT8D high pressure turbine blade and seal were modified, using a more efficient blade cooling system, improved airfoil aerodynamics, more effective control of secondary flows, and improved blade tip sealing. Engine testing was conducted to determine the effect of these improvements on performance. The modified turbine package demonstrated significant thrust specific fuel consumption and exhaust gas temperature improvements in sea level and altitude engine tests. Inspection of the improved blade and seal hardware after testing revealed no unusual wear or degradation.

  1. Optical modeling and physical performances evaluations for the JT-60SA ECRF antenna

    SciTech Connect

    Platania, P. Figini, L.; Farina, D.; Micheletti, D.; Moro, A.; Sozzi, C.; Isayama, A.; Kobayashi, T.; Moriyama, S.

    2015-12-10

    The purpose of this work is the optical modeling and physical performances evaluations of the JT-60SA ECRF launcher system. The beams have been simulated with the electromagnetic code GRASP® and used as input for ECCD calculations performed with the beam tracing code GRAY, capable of modeling propagation, absorption and current drive of an EC Gaussion beam with general astigmatism. Full details of the optical analysis has been taken into account to model the launched beams. Inductive and advanced reference scenarios has been analysed for physical evaluations in the full poloidal and toroidal steering ranges for two slightly different layouts of the launcher system.

  2. Aerodynamic performance of 0.4066-scale model to JT8D refan stage

    NASA Technical Reports Server (NTRS)

    Moore, R. D.; Kovich, G.; Tysl, E. R.

    1976-01-01

    The aerodynamic performance of a scale model of the split flow JT8D rafan stage is presented over a range of flows at speeds from 40 to 100 percent design. The bypass stage peak efficiency of 0.800 occurred at a total weight flow of 35.82 kilograms per second and a pressure ratio of 1.697. The stall margin was 15 percent based on pressure ratio and weight flow at stall and peak efficiency conditions. The data indicated that the hub region of the core stators was choked at design speed over the entire flow range tested.

  3. NASA refan program status. [for noise reduction of JT8D turbofan engine

    NASA Technical Reports Server (NTRS)

    Abdalla, K. L.; Yuska, J. A.

    1975-01-01

    The objective of the refan program is to demonstrate the technical feasibility of substantially reducing the noise levels of existing JT8D powered aircraft. The program consists of the design, manufacturing and testing of the refan engines and modified nacelles and airplanes. Experimental testing was completed for the refan engine both at sea level and at altitude conditions. Ground testing for the B727 side- and center-engine installations and flight testing of the DC-9 with refan engines and acoustic nacelles were performed. Preliminary results presented show that substantial noise reductions were achieved.

  4. ASASSN-16jt: Discovery of A Probable Supernova in ESO 344-G 021

    NASA Astrophysics Data System (ADS)

    Brimacombe, J.; Brown, J. S.; Stanek, K. Z.; Holoien, T. W.-S.; Kochanek, C. S.; Shields, J.; Shappee, B. J.; Prieto, J. L.; Bersier, D.; Dong, Subo; Bose, S.; Chen, Ping; Krannich, G.; Masi, G.; Nicholls, B.; Nicolas, J.; Post, R. S.; Stone, G.

    2016-08-01

    During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy ESO 344-G 021. ASASSN-16jt was discovered in images obtained on UT 2016-08-31.09 at V~16.2 mag. We do not detect (V > 17.8) the object in images taken on UT 2016-08-26.24 and before.

  5. Design of tangential viewing phase contrast imaging for turbulence measurements in JT-60SA

    NASA Astrophysics Data System (ADS)

    Tanaka, K.; Coda, S.; Yoshida, M.; Sasao, H.; Kawano, Y.; Imazawa, R.; Kubo, H.; Kamada, Y.

    2016-11-01

    A tangential viewing phase contrast imaging system is being designed for the JT-60SA tokamak to investigate microturbulence. In order to obtain localized information on the turbulence, a spatial-filtering technique is applied, based on magnetic shearing. The tangential viewing geometry enhances the radial localization. The probing laser beam is injected tangentially and traverses the entire plasma region including both low and high field sides. The spatial resolution for an Internal Transport Barrier discharge is estimated at 30%-70% of the minor radius at k = 5 cm-1, which is the typical expected wave number of ion scale turbulence such as ion temperature gradient/trapped electron mode.

  6. Detailed Analysis of the Transient Voltage in a JT-60SA PF Coil Circuit

    NASA Astrophysics Data System (ADS)

    Yamauchi, K.; Shimada, K.; Terakado, T.; Matsukawa, M.; Coletti, R.; Lampasi, A.; Gaio, E.; Coletti, A.; Novello, L.

    2013-02-01

    A superconducting coil system is actually complicated by the distributed parameters, e.g. the distributed mutual inductance among turns and the distributed capacitance between adjacent conductors. In this paper, such a complicated system was modeled with a reasonably simplified circuit network with lumped parameters. Then, a detailed circuit analysis was conducted to evaluate the possible voltage transient in the coil circuit. As a result, an appropriate (minimum) snubber capacitance for the Switching Network Unit, which is a fast high voltage generation circuit in JT-60SA, was obtained.

  7. Edge safety factor at the onset of plasma disruption during VDEs in JT-60U

    NASA Astrophysics Data System (ADS)

    Sugihara, Masayoshi; Lukash, Victor; Khayrutdinov, Rustam; Neyatani, Yuzuru

    2004-10-01

    Detailed examinations of the value of the edge safety factor (qa) at the onset of thermal quench (TQ) during intentional vertical displacement event (VDE) experiments in JT-60U are carried out using two different reconstruction methods, FBI/FBEQU and DINA. The results from the two methods are very similar and show that the TQ occurs when the qa value is in the range between 1.5 and 2. This result suggests that the predictive simulations for VDEs should be performed within this range of q to examine the subsequent differences in the halo currents, plasma movement and other plasma behaviour during the current quench.

  8. Radio Non-Detection of ASASSN-16jt/SN 2016cvk

    NASA Astrophysics Data System (ADS)

    Ryder, S. D.; Kool, E. C.; Stockdale, C. J.; Kotak, R.; Romero-Canizales, C.; Anderson, G.

    2016-09-01

    The apparently SN 2009ip-like transient ASASSN-16jt coincident with the Type IIn-pec SN 2016cvk (ATel #9439, #9445; http://wis-tns.weizmann.ac.il/object/2016cvk) in the galaxy ESO 344-G021 has been observed with the Australia Telescope Compact Array (ATCA) at 5.5 and 9 GHz on 2016 Sep 4.6 UT. No radio emission was detected at the reported location, to a 3-sigma upper limit of 68 microJy/beam (5.5 GHz) and 75 microJy/beam (9.0 GHz).

  9. JT9D engine diagnostics. Task 2: Feasibility study of measuring in-service flight loads. [747 aircraft performance

    NASA Technical Reports Server (NTRS)

    Kafka, P. G.; Skibo, M. A.; White, J. L.

    1977-01-01

    The feasibility of measuring JT9D propulsion system flight inertia loads on a 747 airplane is studied. Flight loads background is discussed including the current status of 747/JT9D loads knowledge. An instrumentation and test plan is formulated for an airline-owned in-service airplane and the Boeing-owned RA001 test airplane. Technical and cost comparisons are made between these two options. An overall technical feasibility evaluation is made and a cost summary presented. Conclusions and recommendations are presented in regard to using existing inertia loads data versus conducting a flight test to measure inertia loads.

  10. DC-9 Flight Demonstration Program with Refanned JT8D Engines. Volume 3; Performance and Analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The JT8D-109 engine has a sea level static, standard day bare engine takeoff thrust of 73,840 N. At sea level standard day conditions the additional thrust of the JT8D-109 results in 2,040 kg additional takeoff gross weight capability for a given field length. Range loss of the DC-9 Refan airplane for long range cruise was determined. The Refan airplane demonstrated stall, static longitudinal stability, longitudinal control, longitudinal trim, minimum control speeds, and directional control characteristics similar to the DC-9-30 production airplane and complied with airworthiness requirements. Cruise, climb, and thrust reverser performance were evaluated. Structural and dynamic ground test, flight test and analytical results substantiate Refan Program requirements that the nacelle, thrust reverser hardware, and the airplane structural modifications are flightworthy and certifiable and that the airplane meets flutter speed margins. Estimated unit cost of a DC-9 Refan retrofit program is 1.338 million in mid-1975 dollars with about an equal split in cost between airframe and engine.

  11. JT90 Ceramic Outer Air Seal System Refinement Program, Phase 2

    NASA Technical Reports Server (NTRS)

    Shiembob, L. T.

    1982-01-01

    The sprayed ceramic gas turbine outer air seal system was tested in two JT9D engines to substantiate the abradability and durability of the seals. Of particular significance was that one of the tests, a 150 hour 1000 cycle endurance program at nominal JT9D operating conditions, was completed with minimal effect on the seals and received Federal Aviation Administration cognizance with respect to potential field service use by the airlines. The other engine test completed 1825 endurance cycles at severe operating conditions and no burn through or other serious defects in the structural integrity of a seal segment was observed. These test results combined with other Pratt and Whitney Aircraft engine tests substantiate the potential of the ceramic outer air seal system to attain the durability goal of 50000 hour engine operating capability. Both engine tests subjected the seals to intentional blade rubs and demonstrated good abradability with volume wear ratios greater than 100, far exceeding the design goal of 10. The improved volume wear ratio will allow the turbine tip clearance to be reduced, thereby resulting in an estimated thrust specific fuel consumption improvement of 0.3 percent.

  12. Steady-State Operation Scenarios with a Central Current Hole for JT-60SC

    SciTech Connect

    Tamai, Hiroshi; Ishida, Shinichi; Kurita, Gen-Ichi; Shirai, Hiroshi; Tsuchiya, Katsuhiko; Sakurai, Shinji; Matsukawa, Makoto; Sakasai, Akira

    2004-06-15

    A 1.5-dimensional time-dependent transport analysis has been carried out to investigate steady-state operation scenarios with a central current hole by off-axis current drive schemes consistent with a high bootstrap current fraction for the JT-60SC large superconducting tokamak. A steady-state operation scenario with HH{sub y2} = 1.4 and {beta}{sub N} = 3.7 has been obtained at I{sub p} = 1.5 MA, B{sub t} = 2 T, and q{sub 95} = 5, where noninductive currents are developed during the discharge to form a current hole with beam-driven currents by tangential off-axis beams in combination with bootstrap currents by additional on-axis perpendicular beams. The bootstrap fraction increases up to {approx}75% of the plasma current, and the current hole region is enlarged up to {approx}30% of the minor radius at 35 s from the discharge initiation. The current hole is confirmed to be sustained afterward for a long duration of 60 s. The present transport simulation shows that heating equipment designed for JT-60SC is capable of forming and sustaining the current hole only by using off-axis beam-driven currents and bootstrap currents. The stability analysis shows that the beta limit with the conducting wall can be {approx}{beta}{sub N} = 4.5, which is substantially above the no-wall ideal magnetohydrodynamic limit.

  13. JT9D performance deterioration results from a simulated aerodynamic load test

    NASA Technical Reports Server (NTRS)

    Stakolich, E. G.; Stromberg, W. J.

    1981-01-01

    The results of testing to identify the effects of simulated aerodynamic flight loads on JT9D engine performance are presented. The test results were also used to refine previous analytical studies on the impact of aerodynamic flight loads on performance losses. To accomplish these objectives, a JT9D-7AH engine was assembled with average production clearances and new seals as well as extensive instrumentation to monitor engine performance, case temperatures, and blade tip clearance changes. A special loading device was designed and constructed to permit application of known moments and shear forces to the engine by the use of cables placed around the flight inlet. The test was conducted in the Pratt & Whitney Aircraft X-Ray Test Facility to permit the use of X-ray techniques in conjunction with laser blade tip proximity probes to monitor important engine clearance changes. Upon completion of the test program, the test engine was disassembled, and the condition of gas path parts and final clearances were documented. The test results indicate that the engine lost 1.1 percent in thrust specific fuel consumption (TSFC), as measured under sea level static conditions, due to increased operating clearances caused by simulated flight loads. This compares with 0.9 percent predicted by the analytical model and previous study efforts.

  14. DC-9 flight demonstration program with refanned JT8D engines. Volume 4: Flyover noise

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Flyover noise tests were conducted to determine the noise reductions achievable by modifying the engines and nacelles of DC-9-30 airplanes. The two stage fan of the JT8D-9 engine was replaced with a larger diameter, single stage fan and sound absorbing materials were incorporated in the engines and nacelles. The noise levels were determined to be 95.3 EPNdB at the sideline, 96.2 EPNdB for a full thrust takeoff, 87.5 EPNdB for takeoff with thrust cutback, and 97.4 EPNdB for landing approach. The noise reductions relative to the hardwall JT8D-9 were 8.2 EPNdB for takeoff with cutback and 8.7 EPNdB for landing. The 90 EPNdB noise contour areas were reduced by 40% for missions requiring maximum design takeoff and landing weights. For typical mission weights, the reductions were 19% for full thrust takeoff and 34% for takeoff with cutback. The 95 EPNdB contour areas were reduced by 50% for takeoff and 30% for takeoff with cutback for both missions.

  15. Ion temperature profile simulation of JT-60 and TFTR plasmas with ion temperature gradient mode transport models

    NASA Astrophysics Data System (ADS)

    Shirai, H.; Hirayama, T.; Koide, Y.; Yoshida, H.; Naito, O.; Sato, M.; Fukuda, T.; Sugie, T.; Azumi, M.; Mikkelsen, D. R.; Scott, S. D.; Grek, B.; Hill, K. W.; Johnson, D. W.; Mansfield, D. K.; Park, H. K.; Stratton, B. C.; Synakowski, E. J.; Taylor, G.; Towner, H. H.

    1994-05-01

    Ion temperature profiles of neutral beam heated plasmas in JT-60 and TFTR have been simulated using models of ion thermal diffusivity, χi, based on ion temperature gradient mode (ηi mode) turbulence and drift wave turbulence (trapped electron mode and circulating electron mode). The ion temperature profiles measured by charge exchange recombination spectroscopy are compared to predicted Ti profiles calculated from three theoretical models for ion heat transport by Dominguez and Waltz (1987), Lee and Diamond (1986), and Romanelli (1989). All three χi models can reproduce the measured Ti profile over a wide range of parameters in JT-60 L mode plasmas, except for two 1 MA limiter cases. With the use of transport models, which were adjusted to fit JT-60 plasmas, it was found that the Dominguez and Waltz and Romanelli models agree with measured Ti, profiles in TFTR L mode discharges in the region a/4 < r < a/2. The observed central peaking of Ti near the magnetic axis of TFTR L mode plasmas cannot be reproduced. It was found that the Lee and Diamond model does not fit me data as well. The χi models studied cannot consistently reproduce the measured Ti in the peripheral region of either JT-60 or TFTR plasmas. In the high ion temperature (high Ti) plasmas of JT-60 and supershot plasmas of TFTR, the predicted Ti profiles are much broader than the measured profile. In supershot plasmas, the measured central ion temperature greatly exceeds the predicted temperature, although there is reasonable agreement near the edge

  16. Radial Patterns of Instability and Transport in JT-60U Internal Transport Barrier Discharges

    SciTech Connect

    G. Rewoldt; K.W. Hill; R. Nazikian; W.M. Tang; H Shirai; Y. Sakamoto; Y. Kishimoto; S.Ide; and T. Fujita

    2001-02-27

    One class of internal transport barrier discharges in the JT-60U tokamak is characterized by two relatively flatter regions of the pressure separated by a region with very large pressure gradient. Linear growth rates for toroidal drift-type modes are calculated for discharges in this class, without and with sheared E x B rotation effects. For cases with fully-developed barriers, the results with rotation are consistent with a picture in which the radial electric field generated in part by the steep pressure gradient causes local stabilization, and thus reduction of the local anomalous transport, which allows the steep pressure gradient to persist. If rotation is omitted from the calculation for these cases, or if rotation is included for cases without barriers or with partially developed barriers, the unstable region spreads into the steep pressure gradient region.

  17. The 727 airplane target thrust reverser static performance model test for refanned JT8D engines

    NASA Technical Reports Server (NTRS)

    Chow, C. T. P.; Atkey, E. N.

    1974-01-01

    The results of a scale model static performance test of target thrust reverser configurations for the Pratt and Whitney Aircraft JT8D-100 series engine are presented. The objective of the test was to select a series of suitable candidate reverser configurations for the subsequent airplane model wind tunnel ingestion and flight controls tests. Test results indicate that adequate reverse thrust performance with compatible engine airflow match is achievable for the selected configurations. Tapering of the lips results in loss of performance and only minimal flow directivity. Door pressure surveys were conducted on a selected number of lip and fence configurations to obtain data to support the design of the thrust reverser system.

  18. JT8D revised high-pressure turbine cooling and other outer air seal program

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1979-01-01

    The JT8D high pressure turbine was revised to reduce leakage between the blade tip shrouds and the outer air seal, and engine testing was performed to determine the effect on performance. The addition of a second knife-edge on the blade tip shroud, the extension of the honeycomb seal land to cover the added knife-edge and an existing spoiler on the shroud, and a material substitution in the seal support ring to improve thermal growth characteristics are included. A relocation of the blade cooling air discharge to insure adequate cooling flow is required. Significant specific fuel consumption and exhaust gas temperature improvements were demonstrated with the revised turbine in sea level and simulated altitude engine tests. Inspection of the revised seal hardware after these tests showed no unusual wear or degradation.

  19. Fast neutron-gamma discrimination on neutron emission profile measurement on JT-60U

    SciTech Connect

    Ishii, K.; Okamoto, A.; Kitajima, S.; Sasao, M.; Shinohara, K.; Ishikawa, M.; Baba, M.; Isobe, M.

    2010-10-15

    A digital signal processing (DSP) system is applied to stilbene scintillation detectors of the multichannel neutron emission profile monitor in JT-60U. Automatic analysis of the neutron-{gamma} pulse shape discrimination is a key issue to diminish the processing time in the DSP system, and it has been applied using the two-dimensional (2D) map. Linear discriminant function is used to determine the dividing line between neutron events and {gamma}-ray events on a 2D map. In order to verify the validity of the dividing line determination, the pulse shape discrimination quality is evaluated. As a result, the {gamma}-ray contamination in most of the beam heating phase was negligible compared with the statistical error with 10 ms time resolution.

  20. High performance reversed shear plasmas with a large radius transport barrier in JT-60U

    NASA Astrophysics Data System (ADS)

    Fujita, T.; Hatae, T.; Oikawa, T.; Takeji, S.; Shirai, H.; Koide, Y.; Ishida, S.; Ide, S.; Ishii, Y.; Ozeki, T.; Higashijima, S.; Yoshino, R.; Kamada, Y.; Neyatani, Y.

    1998-02-01

    The operation of reversed shear plasmas in JT-60U has been extended to the low-q, high-Ip region keeping a large radius transport barrier, and a high fusion performance has been achieved. Record values of deuterium-tritium (DT)-equivalent power gain in JT-60U have been obtained: QDTeq = 1.05, τE = 0.97 s, nD(0) = 4.9 × 1019 m-3 and Ti(0) = 16.5 keV. A large improvement in confinement resulted from the formation of an internal transport barrier (ITB) with a large radius, which was characterized by steep gradients in electron density, electron temperature and ion temperature just inside the position of qmin. Large negative shear regions, up to 80% of the plasma minor radius in the low-qmin regime (qmin~2), were obtained by plasma current ramp-up after the formation of the ITB with the pressure and current profiles being controlled by adjustment of plasma volume and beam power. The ITB was established by on-axis beam heating into a low density target plasma with reversed shear that was formed by current ramp-up without beam heating. The confinement time increased with the radius of the ITB and the decrease of qmin at a fixed toroidal field. High H factors, up to 3.3, were achieved with an L mode edge. The effective one fluid thermal diffusivity χeff had its minimum in the ITB. The values of H/q95 and βt increased with the decrease of q95, and the highest performance was achieved at q95 ~3.1 (2.8 MA). The performance was limited by disruptive beta collapses with βN~2 at qmin~2.

  1. Simulation of plasma current ramp-up with reduced magnetic flux consumption in JT-60SA

    NASA Astrophysics Data System (ADS)

    Wakatsuki, T.; Suzuki, T.; Hayashi, N.; Shiraishi, J.; Ide, S.; Takase, Y.

    2015-06-01

    Current ramp-up with reduced central solenoid (CS) flux consumption in JT-60SA has been investigated using an integrated modeling code suite (TOPICS) with a turbulent model (CDBM). The plasma current can be ramped-up from 0.6 MA to 2.1 MA with no additional CS flux consumption if the plasma current is overdriven by neutral-beam-driven and bootstrap current. A time duration required for the current ramp-up without CS flux consumption becomes as long as 150 s in the scenario we have examined. In order to achieve a current overdrive condition from 0.6 MA, the current drive by a lower energy neutral beam (85 keV) is effective. A higher energy neutral beam (500 keV) cannot be used in this early phase with a low central electron density (~2 × 1019 m-3) due to large shine through loss, while it can be effectively used in the later phase. Therefore, the main current driver should be switched from the lower energy neutral beam to the higher energy neutral beam during the current ramp-up phase. As a result of an intensive auxiliary heating, plasma beta (the ratio of the plasma pressure to the magnetic pressure) becomes high. Ideal MHD instabilities of such high beta plasmas have been investigated using a linear ideal MHD stability analysis code (MARG2D). External kink modes which might affect the core plasma can be stabilized during the current ramp-up if there is a perfectly conducting wall at the location of the stabilizing plate and the vacuum vessel of JT-60SA and the plasma has a broader pressure profile with the H-mode pedestal and the internal transport barrier.

  2. Design optimization for plasma performance and assessment of operation regimes in JT-60SA

    NASA Astrophysics Data System (ADS)

    Fujita, T.; Tamai, H.; Matsukawa, M.; Kurita, G.; Bialek, J.; Aiba, N.; Tsuchiya, K.; Sakurai, S.; Suzuki, Y.; Hamamatsu, K.; Hayashi, N.; Oyama, N.; Suzuki, T.; Navratil, G. A.; Kamada, Y.; Miura, Y.; Takase, Y.; Campbell, D.; Pamela, J.; Romanelli, F.; Kikuchi, M.

    2007-11-01

    The design of the modification of JT-60U, JT-60SA has been optimized from the viewpoint of plasma performance, and operation regimes have been evaluated with the latest design. Upper and lower divertors with different geometries will be prepared for flexibility of the plasma shape, which will enable both low aspect ratio (A ~ 2.65) and ITER shape (A = 3.1) configurations. The beam lines of negative-ion neutral beam injection will be shifted downwards by ~0.6 m for the off-axis current drive (CD), in order to obtain a weak/reversed shear plasma, as well as having the capability of heating the central region. The feedback control coils along the openings in the stabilizing plate are found effective in suppressing the resistive wall mode and sustaining high βN close to the ideal wall limit. Sustainment of plasma current of 3-3.5 MA for 100 s will be possible in ELMy H-mode plasmas with moderate heating power, βN, and density within an available flux swing. It is also expected that higher βN, high-density ELMy H-mode plasmas will be maintained for 100 s with higher heating power. The expected regime of full CD operation has been extended with upgraded heating and CD power. Full CD operation for 100 s with reactor-relevant high values of normalized beta and bootstrap current fraction (Ip = 2.4 MA, βN = 4.3, fBS = 0.69, \\bar{n}_{\\rme}/n_GW = 0.86 , HH98y2 = 1.3) is expected in a highly-shaped low-aspect-ratio configuration (A = 2.65).

  3. Comparison of several inflow control devices for flight simulation of fan tone noise using a JT15D-1 engine

    NASA Technical Reports Server (NTRS)

    Mcardie, J. G.; Jones, W. L.; Heidelberg, L. J.; Homyak, L.

    1980-01-01

    The paper describes the tests of four devices intended to reduce inflow disturbances and turbulences using a JT15D-1 turbofan engine. The tests were made to simulate the in-flight fan tone noise; the inflow control devices (ICD's) consisted of honeycomb/screen structures mounted over the engine inlet. The ICD's ranged from 1.6 to 4 fan diameters in size, and were made with several fabrication methods. All the ICD's significantly reduced the BPF tone in the far-field directivity patterns, but the smallest ICD's introduced propagating modes which could be recognized by additional lobes in the patterns. The JT15D-1 engine had a tone source which generated a strong propagating mode at fan speeds corresponding to 'approach' power and higher. Data from a typical transducer showed that the unsteady inflow distortion modes were eliminated or reduced when either of the ICD's was installed.

  4. Finite element-integral simulation of static and flight fan noise radiation from the JT15D turbofan engine

    NASA Astrophysics Data System (ADS)

    Baumeister, K. J.; Horowitz, S. J.

    An iterative finite element integral technique is used to predict the sound field radiated from the JT15D turbofan inlet. The sound field is divided into two regions: the sound field within and near the inlet which is computed using the finite element method and the radiation field beyond the inlet which is calculated using an integral solution technique. The velocity potential formulation of the acoustic wave equation was employed in the program. For some single mode JT15D data, the theory and experiment are in good agreement for the far field radiation pattern as well as suppressor attenuation. Also, the computer program is used to simulate flight effects that cannot be performed on a ground static test stand.

  5. Improvement of voltage holding capability in the 500 keV negative ion source for JT-60SA.

    PubMed

    Tanaka, Y; Hanada, M; Kojima, A; Akino, N; Shimizu, T; Ohshima, K; Inoue, T; Watanabe, K; Taniguchi, M; Kashiwagi, M; Umeda, N; Tobari, H; Grisham, L R

    2010-02-01

    Voltage holding capability of JT-60 negative ion source that has a large electrostatic negative ion accelerator with 45 cm x 1.1 m acceleration grids was experimentally examined and improved to realize 500 keV, 22 A, and 100 s D- ion beams for JT-60 Super Advanced. The gap lengths in the acceleration stages were extended to reduce electric fields in a gap between the large grids and at the corner of the support flanges from the original 4-5 to 3-4 kV/mm. As a result, the voltage holding capability without beam acceleration has been successfully improved from 400 to 500 kV. The pulse duration to hold 500 kV reached 40 s of the power supply limitation.

  6. Development of the negative ion beams relevant to ITER and JT-60SA at Japan Atomic Energy Agency.

    PubMed

    Hanada, M; Kojima, A; Tobari, H; Nishikiori, R; Hiratsuka, J; Kashiwagi, M; Umeda, N; Yoshida, M; Ichikawa, M; Watanabe, K; Yamano, Y; Grisham, L R

    2016-02-01

    In order to realize negative ion sources and accelerators to be applicable to International Thermonuclear Experimental Reactor and JT-60 Super Advanced, a large cesium (Cs)-seeded negative ion source and a multi-aperture and multi-stage electric acceleration have been developed at Japan Atomic Energy Agency (JAEA). Long pulse production and acceleration of the negative ion beams have been independently carried out. The long pulse production of the high current beams has achieved 100 s at the beam current of 15 A by modifying the JT-60 negative ion source. The pulse duration time is increased three times longer than that before the modification. As for the acceleration, a pulse duration time has been also extended two orders of magnitudes from 0.4 s to 60 s. The developments of the negative ion source and acceleration at JAEA are well in progress towards the realization of the negative ion sources and accelerators for fusion applications. PMID:26932050

  7. Development of the negative ion beams relevant to ITER and JT-60SA at Japan Atomic Energy Agency.

    PubMed

    Hanada, M; Kojima, A; Tobari, H; Nishikiori, R; Hiratsuka, J; Kashiwagi, M; Umeda, N; Yoshida, M; Ichikawa, M; Watanabe, K; Yamano, Y; Grisham, L R

    2016-02-01

    In order to realize negative ion sources and accelerators to be applicable to International Thermonuclear Experimental Reactor and JT-60 Super Advanced, a large cesium (Cs)-seeded negative ion source and a multi-aperture and multi-stage electric acceleration have been developed at Japan Atomic Energy Agency (JAEA). Long pulse production and acceleration of the negative ion beams have been independently carried out. The long pulse production of the high current beams has achieved 100 s at the beam current of 15 A by modifying the JT-60 negative ion source. The pulse duration time is increased three times longer than that before the modification. As for the acceleration, a pulse duration time has been also extended two orders of magnitudes from 0.4 s to 60 s. The developments of the negative ion source and acceleration at JAEA are well in progress towards the realization of the negative ion sources and accelerators for fusion applications.

  8. Assessment of the accuracy of plasma shape reconstruction by the Cauchy condition surface method in JT-60SA

    SciTech Connect

    Miyata, Y.; Suzuki, T.; Takechi, M.; Urano, H.; Ide, S.

    2015-07-15

    For the purpose of stable plasma equilibrium control and detailed analysis, it is essential to reconstruct an accurate plasma boundary on the poloidal cross section in tokamak devices. The Cauchy condition surface (CCS) method is a numerical approach for calculating the spatial distribution of the magnetic flux outside a hypothetical surface and reconstructing the plasma boundary from the magnetic measurements located outside the plasma. The accuracy of the plasma shape reconstruction has been assessed by comparing the CCS method and an equilibrium calculation in JT-60SA with a high elongation and triangularity of plasma shape. The CCS, on which both Dirichlet and Neumann conditions are unknown, is defined as a hypothetical surface located inside the real plasma region. The accuracy of the plasma shape reconstruction is sensitive to the CCS free parameters such as the number of unknown parameters and the shape in JT-60SA. It is found that the optimum number of unknown parameters and the size of the CCS that minimizes errors in the reconstructed plasma shape are in proportion to the plasma size. Furthermore, it is shown that the accuracy of the plasma shape reconstruction is greatly improved using the optimum number of unknown parameters and shape of the CCS, and the reachable reconstruction errors in plasma shape and locations of strike points are within the target ranges in JT-60SA.

  9. A 727 airplane center duct inlet low speed performance confirmation model test for refanned JT8D engines, phase 2

    NASA Technical Reports Server (NTRS)

    Kaldschmidt, G.; Syltebo, B. E.; Ting, C. T.

    1973-01-01

    The results from testing of a 0.3 scale model center duct inlet (S duct) for the Pratt and Whitney Aircraft JT8D-100 engines are presented. The objective of this test was to demonstrate that the required airflow of the JT8D-100 engine (480 lb/sec as compared to 334 lb/sec for JT8D-15) can be achieved with minimum modifications to the existing 727 airplane structure at acceptable levels of total pressure recovery and distortion. Steady-state pressure recovery, steady-state pressure distortion, and dynamic pressure measurements were taken at the engine face station. Surface static pressure measurements were taken along the duct. Test results indicated that the required airflow was achieved with acceptable pressure recovery (comparable to the current 727-200 S duct). Inlet inflow angle variation within the 727 airplane operating regime (minus 5 to 5 degrees) had no effect on the inlet performance. Pressure distortion at static and forward speed at takeoff airflow conditions are within P and WA limits for the Phase II duct when equipped with vortex generators. Static crosswind operation between 10 knots and 25 knots appears feasible at full takeoff power.

  10. Development of Fast Measurement System of Neutron Emission Profile Using a Digital Signal Processing Technique in JT-60U

    SciTech Connect

    Ishikawa, M.; Shinohara, K.; Itoga, T.; Okuji, T.; Nakhostin, M.; Baba, M.; Nishitani, T.

    2008-03-12

    Neutron emission profiles are routinely measured in JT-60U Tokamak. Stinbene neuron detectors (SNDs), which combine a Stilbene organic crystal scintillation detector (Stilbene detector) with an analog neutron-gamma pulse shape discrimination (PSD) circuit, have been used to measure neutron flux efficiently. Although the SND has many advantages as a neutron detector, the maximum count rate is limited up to {approx}1x 10{sup 5} counts/s due to the dead time of the analog PSD circuit. To overcome this issue, a digital signal processing (DSP) system using a Flash-ADC has been developed. In this system, anode signals from the photomultiplier of the Stilbene detector are fed to the Flash ADC and digitized. Then, the PSD between neutrons and gamma-rays are performed using software. The photomultiplier tube is also modified to suppress and correct gain fluctuation of the photomultiplier. The DSP system has been installed in the center channel of the vertical neutron collimator system in JT-60U and applied to measurements of neutron flux in JT-60U experiments. Neutron flux are successfully measured with count rate up to {approx}1x 10{sup 6} counts/s without the effect of pile up of detected pulses. The performance of the DSP system as a neutron detector is demonstrated.

  11. Introduction of a Saturated Bath in Vincenta Models: Application to the Cryogenic System for JT-60SA Tokamak

    NASA Astrophysics Data System (ADS)

    Rousset, B.; Roussel, P.; Michel, F.; Hitz, D.

    2010-04-01

    The CEA is involved in large helium refrigeration applied to the future experimental fusion reactors (e.g. ITER or JT-60SA). Pulsed operation of such machines results in heat load variations which the refrigerators have to cope with. One solution to smooth pulsed loads is to use a large thermal buffer, and in the case of JT-60SA cryogenic system, a saturated thermal bath is one of the investigated solutions. A 1D thermo hydraulic model describing the cooling loop associated with TF (Toroidal Field) coils and TF casing has been developed using Vincenta code to calculate the heat load arriving to the buffer (saturated bath). However, the liquid helium buffer itself and its coupling with the primary loop was not modelized. This paper shows results obtained using the existing functionalities in Vincenta code to model a saturated bath. For very large bath volumes, bath temperature remains almost steady and the power removed is equal to those previously calculated. On the other side, for smaller buffer volumes (e.g. JT-60SA scheme), it has been found that the increase of temperature fluctuations does not vary proportionally with the decrease of the buffer volume.

  12. Performance deterioration due to acceptance testing and flight loads; JT90 jet engine diagnostic program

    NASA Technical Reports Server (NTRS)

    Olsson, W. J.

    1982-01-01

    The results of a flight loads test of the JT9D-7 engine are presented. The goals of this test program were to: measure aerodynamic and inertia loads on the engine during flight, explore the effects of airplane gross weight and typical maneuvers on these flight loads, simultaneously measure the changes in engine running clearances and performance resulting from the maneuvers, make refinements of engine performance deterioration prediction models based on analytical results of the tests, and make recommendations to improve propulsion system performance retention. The test program included a typical production airplane acceptance test plus additional flights and maneuvers to encompass the range of flight loads in revenue service. The test results indicated that aerodynamic loads, primarily at take-off, were the major cause of rub-indicated that aerodynamic loads, primarily at take-off, were the major cause of rub-induced deterioration in the cold sectin of the engine. Differential thermal expansion between rotating and static parts plus aerodynamic loads combined to cause blade-to-seal rubs in the turbine.

  13. Sensitivity study for N-NB-driven modes in JT-60U: boundary, diffusion, gyroaverage, compressibility

    NASA Astrophysics Data System (ADS)

    Bierwage, A.; Todo, Y.; Aiba, N.; Shinohara, K.

    2016-10-01

    The sensitivity of the growth and nonlinear evolution of fast-ion-driven modes is examined with respect to the choice of particle boundary conditions, diffusion coefficients, fast ion gyroradii and bulk compressibility. The primary purpose of this work is to justify the choice of parameters to be used in the self-consistent long-time simulations of fast ion dynamics using global MHD-kinetic hybrid codes that include fast ion sources and collisions. The present study is conducted for a scenario based on the N-NB-driven JT-60U shot E039672, which is subject to abrupt large events (ALE). We use realistic geometry, a realistic fast ion distribution, and focus on experimentally observed harmonics with low toroidal mode numbers n  =  1, 2, 3. The use of realistic boundary conditions and finite Larmor radii for the fast ions is shown to be essential. The usual values {μ0}η =ν =χ ∼ {{10}-6}{{v}\\text{A0}}{{R}0} used for resistivity, viscosity and thermal diffusivity, and Γ=5/3 used for the specific heat ratio (controlling the effect of compressibility) are shown to be reasonable choices. Our method for performing the parameter scans around the threshold for the onset of convective amplification is proposed as a strategy for nonlinear benchmark studies.

  14. JT150 1/2-scale nozzle jet noise experiment and comparison with prediction

    NASA Astrophysics Data System (ADS)

    Groesbeck, D. E.; Wasserbauer, C. A.

    1983-05-01

    As part of a program to study flight effects on the exhaust noise of a full scale JT15D engine, static half scale model jet noise experiments were conducted. Acoustic data were recorded for microphone angles of 45 deg to 155 deg with jet conditions for the model scale nozzle corresponding closely to those at 55, 73 and 97 percent of corrected rated speed for the full scale engine. These data are useful for determining the relative importance of jet and core noise in the static full scale engine test data and will in turn allow for a proper evaluation of flight effects on the exhaust noise results. The model scale data are also compared with the coaxial jet noise prediction. Above 1000 Hz, the prediction is nominally 0 to 3 dB higher than the data. The arithmetic mean of the differences between the experimental OASPL and the predicted OASPL for all angles for each run ranged from 0 to -3.2 dB. The standard deviation of all the OASPL differences is 2.2 dB. The discrepancies are greatest at low primary jet velocities and appear to be due to inadequacy in the variable jet density exponent incorporated in the prediction procedure.

  15. Pressure transfer function of a JT15D nozzle due to acoustic and convected entropy fluctuations

    NASA Astrophysics Data System (ADS)

    Miles, J. H.

    An acoustic transmission matrix analysis of sound propagation in a variable area duct with and without flow is extended to include convected entropy fluctuations. The boundary conditions used in the analysis are a transfer function relating entropy and pressure at the nozzle inlet and the nozzle exit impedance. The nozzle pressure transfer function calculated is compared with JT15D turbofan engine nozzle data. The one dimensional theory for sound propagation in a variable area nozzle with flow but without convected entropy is good at the low engine speeds where the nozzle exit Mach number is low (M=0.2) and the duct exit impedance model is good. The effect of convected entropy appears to be so negligible that it is obscured by the inaccuracy of the nozzle exit impedance model, the lack of information on the magnitude of the convected entropy and its phase relationship with the pressure, and the scatter in the data. An improved duct exit impedance model is required at the higher engine speeds where the nozzle exit Mach number is high (M=0.56) and at low frequencies (below 120 Hz).

  16. Pressure transfer function of a JT15D nozzle due to acoustic and convected entropy fluctuations

    NASA Technical Reports Server (NTRS)

    Miles, J. H.

    1982-01-01

    An acoustic transmission matrix analysis of sound propagation in a variable area duct with and without flow is extended to include convected entropy fluctuations. The boundary conditions used in the analysis are a transfer function relating entropy and pressure at the nozzle inlet and the nozzle exit impedance. The nozzle pressure transfer function calculated is compared with JT15D turbofan engine nozzle data. The one dimensional theory for sound propagation in a variable area nozzle with flow but without convected entropy is good at the low engine speeds where the nozzle exit Mach number is low (M=0.2) and the duct exit impedance model is good. The effect of convected entropy appears to be so negligible that it is obscured by the inaccuracy of the nozzle exit impedance model, the lack of information on the magnitude of the convected entropy and its phase relationship with the pressure, and the scatter in the data. An improved duct exit impedance model is required at the higher engine speeds where the nozzle exit Mach number is high (M=0.56) and at low frequencies (below 120 Hz).

  17. Performance deterioration based on in-service engine data: JT9D jet engine diagnostics program

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.

    1979-01-01

    Results of analyses of engine performance deterioration trends and levels with respect to service usage are presented. Thirty-two JT9D-7A engines were selected for this purpose. The selection of this engine fleet provided the opportunity of obtaining engine performance data starting before the first flight through initial service such that the trend and levels of engine deterioration related to both short and long term deterioration could be more carefully defined. The performance data collected and analyzed included in-flight, on wing (ground), and test stand prerepair and postrepair performance calibrations with expanded instrumentation where feasible. The results of the analyses of these data were used to: (1) close gaps in previously obtained historical data as well as augment the historical data with more carefully obtained data; (2) refine preliminary models of performance deterioration with respect to usage; (3) establish an understanding of the relationships between ground and altitude performance deterioration trends; (4) refine preliminary recommendations concerning means to reduce and control deterioration; and (5) identify areas where additional effort is required to develop an understanding of complex deterioration issues.

  18. Gaseous exhaust emissions from a JT8D-109 turbofan engine at simulated cruise flight conditions

    NASA Technical Reports Server (NTRS)

    Diehl, L. A.; Holdeman, J. D.

    1975-01-01

    Gaseous emissions from a JT8D-109 turbofan engine were measured in an altitude facility at four simulated cruise flight conditions: Mach 0.8 at altitudes of 9.1, 10, 7, and 12.2 km and Mach 0.9 at 10.7 km. Engine inlet air temperature was held constant at 283 K for all tests. Emissions measurements were made at nominally 6 cm intervals across the horizontal diameter of the engine exhaust nozzle with a single-point traversing gas sample probe. Measured emissions of decreased with increasing altitude from an emission index of 10.4 to one of 8.3, while carbon monoxide increased with increasing altitude from an emission index of 1.6 to one of 4.4. Unburned hydrocarbon emissions were essentially negligible for all flight conditions. Since the engine inlet air temperatures were not correctly simulated, the NOx emission indices were corrected to true altitude conditions by using correlating parameters for changes in combustor inlet temperature, pressure, and temperature rise. The correction was small at the lowest altitude. At the 10.7 and 12.2 km, Mach 0.8 test conditions the correction decreased the measured values by 1 emission index.

  19. Behaviour of tritium in the vacuum vessel of JT-60U

    SciTech Connect

    Kobayashi, K.; Miya, N.; Ikeda, Y.; Torikai, Y.; Saito, M.; Alimov, V.

    2015-03-15

    The disassembly of the JT-60U torus started in 2010 after 18 years of deuterium plasma operations. The vessel is made of Inconel 625. Therefore, it was very important to study the hydrogen isotope (particularly tritium) behavior in Inconel 625 from the viewpoint of the clearance procedure. Inconel 625 specimen was exposed to the D{sub 2} (92.8 %) - T{sub 2} (7.2 %) gas mixture at 573 K for 5 hours. The tritium release from the specimen at 298 K was controlled for about 1 year. After that a part of tritium remaining in the specimen was released by heating up to 1073 K. Other part of tritium trapped in the specimen was measured by chemical etching method. Most of the chemical form of the released tritium was HTO. The contaminated specimen by tritium was released continuously the diffusible tritium under the ambient condition. In the tritium release experiment, the amount of desorbed tritium was about 99% during 1 year. It was considered that the tritium in Inconel 625 was released easily.

  20. Investigation of carbon dust accumulation in the JT-60U tokamak vacuum vessel

    NASA Astrophysics Data System (ADS)

    Asakura, N.; Hayashi, T.; Ashikawa, N.; Fukumoto, M.

    2013-07-01

    Dust generated by plasma-wall interaction is a potential source of tritium retention in a fusion reactor. Evaluation of the dust accumulation in the entire vacuum vessel is required to estimate the total amount of tritium retention, but it was particularly difficult to measure for plasma-unexposed areas behind the PFC structures, i.e. "shadow areas". Dust samples were collected at 3, 5 and 2-4 different toroidal locations on the first wall, divertor surface and the exhaust route under the divertor in JT-60U, respectively. On the tile surface, large mass area density was found at the inner divertor and baffle, in particular, upper tiles compared to the lower target tile where the thick deposition layers were produced. Mass area density was significantly increased at the shadow areas, i.e. under the divertor structure such as the divertor and baffle tiles and the divertor dome. It was found that the poloidal distribution is relatively symmetrical in the toroidal direction within a factor of three. In comparison with the previous collection just before major change of the plasma operations, dust accumulation was increased both at the exposed and shadow areas due to change in the operating conditions.

  1. Performance deterioration based on existing (historical) data; JT9D jet engine diagnostics program

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.

    1978-01-01

    The results of the collection and analysis of historical data pertaining to the deterioration of JT9D engine performance are presented. The results of analyses of prerepair and postrepair engine test stand performance data from a number of airlines to establish the individual as well as average losses in engine performance with respect to service use are included. Analysis of the changes in mechanical condition of parts, obtained by inspection of used gas-path parts of varying age, allowed preliminary assessments of component performance deterioration levels and identification of the causitive factors. These component performance estimates, refined by data from special engine back-to-back testing related to module performance restoration, permitted the development of preliminary models of engine component/module performance deterioration with respect to usage. The preliminary assessment of the causes of module performance deterioration and the trends with usage are explained, along with the role each module plays in overall engine performance deterioration. Preliminary recommendations with respect to operating and maintenance practices which could be adopted to control the level of performance deterioration are presented. The needs for additional component sensitivity testing as well as outstanding issues are discussed.

  2. Recovery of Retained Tritium from Graphite Tile of JT-60U

    SciTech Connect

    Takeishi, Toshiharu; Katayama, Kazunari; Nishikawa, Masabumi; Miya, Naoyuki; Masaki, Kei

    2005-07-15

    Tritium thermal release and full combustion with oxygen were performed on isotropic graphite tiles used for plasma facing material of JT-60U. Approximately 50-80 % of tritium was released by dry argon gas purge and 20-50 % of tritium was released by humid argon gas purge up to 800-1200 deg. C within one day, respectively. Further several percent of tritium was released by full combustion with oxygen. It was experimentally confirmed that all retained tritium is not released by thermal dry gas purge and by use of isotope exchange reaction at high temperature in such a short period. In the full combustion operation, isotropic graphite begins to combust at higher temperature than 650 deg. C, but effective combustion temperature was higher than 700 deg. C. Since it is very difficult to heat the graphite tile attached on the wall of vacuum vessel at higher than 700 deg. C, it is considered to be not easy to recover all the tritium retained in the graphite while in the vacuum vessel.

  3. EleFantastic Bingo.

    ERIC Educational Resources Information Center

    Rule, Audrey C.

    This game allows students to learn new science vocabulary and relevant facts about elephants. This bingo game is a valuable curriculum resource for any teacher who is teaching about elephants or other endangered animals. Directions for play, calling cards (six to a page), and play cards (four to a page), are included. (ASK)

  4. Characterization of sorption compressor for mixed refrigerant J-T cryocooler

    NASA Astrophysics Data System (ADS)

    Mehta, Rohitkumar; Bapat, Shridhar; Atrey, Milind

    2012-06-01

    The requirement of a cryocooler with minimum vibrations for space borne system and highly sophisticated electronic devices for ground application, has led to the development of sorption compressor type J-T cryocooler. The adsorption capacity of any adsorbent material increases with an increase in pressure and decreases with an increase in temperature. In a Sorption compressor, adsorbed gases are desorbed in a confined volume by raising temperature of the sorption bed which results in increase in pressure of gas. A uniform temperature across the sorption bed ensures maximum discharge from the compressor amounting to higher flow rates and longer cycle time on account of reduced residual loading. In addition, it is also very important to determine the adsorption capacity of any material with respect to the gas or gases to be adsorbed as this varies with source of the adsorbent. The present work reports the characterization of a fully operational two-cell sorption compressor developed. The sorption compressor is characterized for discharge pressure variation with cycle time; this is essentially a function of a) the amount of adsorbent, b) the adsorption capacity for respective gas or gases, c) desorption temperature and its uniformity, and d) system dead volume. The present paper analyses these aspects theoretically and the results are compared with the experimental data obtained for individual gases as well as for gas mixtures. The effect of gas distribution on temperature uniformity across the bed and of heater power on high pressure generated is also studied. The paper also discusses the pressure profile obtained for a given amount of adsorbent for different gas or gas mixture. The work, based on the results obtained so far is being further extended for a four cell sorption compressor.

  5. Removal of the deposition on JT-60 tile by nano-sec pulsed-laser irradiation

    NASA Astrophysics Data System (ADS)

    Sugiyama, K.; Sakawa, Y.; Tanabe, T.; Watanabe, D.; Shibahara, T.; Masaki, K.

    2010-10-01

    To clarify the property of tritium removal from carbon codeposition by using pulsed-laser induced desorption, hydrogen removal from co-deposits on JT-60 divertor tile using a fourth-harmonic emission (266 nm) of a nano-sec Nd:YAG laser was demonstrated. The threshold laser fluence for ablation was ˜0.3 J/cm 2, which was slightly higher compared to that of the pico-sec laser irradiation. The energy absorption coefficient for the nano-sec laser, which was obtained by fitting the removal rate by so-called Beer's law, was larger than the pico-sec laser. Since the time constant of thermal wave propagation into the target is of the order of nano-sec, such differences between nano- and pico-sec lasers could be attributed to thermal effects. The ablation threshold of the deposited layer was lower than that of a pure graphite, which could be attributed to the difference of thermal conductivity between deposited layer and pure graphite. The removal rate of the nano-sec laser was higher than that of pico-sec laser in the fluence range of >˜0.5 J/cm 2. On the other hand, the production ratio [hydrocarbon species]/[H 2] continuously increased with the laser fluence, and no significant ionization of carbon was observed in this fluence range. This indicated that the fluence range in this study was "weak"-ablation range, which was still not sufficient to minimize the hydrocarbon production.

  6. Effect of ceramic coating of JT8D combustor liner on maximum liner temperatures and other combustor performance parameters

    NASA Technical Reports Server (NTRS)

    Butze, H. F.; Liebert, C. H.

    1976-01-01

    The effect of ceramic coating of a JT8D combustor liner was investigated at simulated cruise and takeoff conditions with two fuels of widely different aromatic contents. Substantial decreases in maximum liner temperatures and flame radiation values were obtained with the ceramic-coated liner. Small reductions in exhaust gas smoke concentrations were observed with the ceramic-coated liner. Other performance parameters such as combustion efficiency and emissions of unburned hydrocarbons, CO, and NOx were not affected significantly. No deterioration of the ceramic coating was observed after about 6 hours of cyclic operation including several startups and shutdowns.

  7. Preliminary core-engine noise abatement experimental results of a fluid injection nozzle on a JT-15D turbofan engine

    NASA Technical Reports Server (NTRS)

    Cheng, D. Y.; Wang, P.

    1975-01-01

    Jet noise, as induced by shear stress, in an jet exhaust is investigated. Experiments were performed on a JT-15D fan jet to verify the inward momentum stress reduction concept. The experiments involved making fan air flow convergently around the high velocity core jet with a small angle. Ring airfoils were used as flow separators for the minimization of the thrust loss. Jet exhaust noise reduction of ll db at 30 deg from the jet axis was recorded and 8 db integrated overall noise reduction over a hemisphere was measured with only 4.6% thrust loss, or 152 db/percent thrust loss.

  8. Module-type flat-field grazing-incidence spectrographs for large Tokamak (JT-60) plasma diagnosis

    NASA Astrophysics Data System (ADS)

    Nagata, Hiroshi; Kihara, Naoto; Yamashita, Takaji; Sugie, Tatsuo; Kubo, Hirotaka; Shiho, Makoto

    1990-09-01

    Module-type flat-field grazing-incidence spectrographs with holographic gratings and multichannel detectors for large TOKAMAK (JT-60) plasma diagnosis are developed. The spectrographs cover the different wavelength regions from 0.5-122 nm, and are set to measure impurity lines in the plasma every 20 ms with space resolution of 7 cm. The flat-field imaging properties with designed wavelength resolution were confirmed, and results of tokamak plasma measurements proved the value of these spectrographs for plasma diagnosis.

  9. Compact antenna for two-dimensional beam scan in the JT-60U electron cyclotron heating/current drive system

    SciTech Connect

    Moriyama, S.; Kajiwara, K.; Takahashi, K.; Kasugai, A.; Seki, M.; Ikeda, Y.; Fujii, T.

    2005-11-15

    A compact antenna system was designed and fabricated to enable millimeter-wave beam scanning in the toroidal and poloidal directions of the JT-60U tokamak for electron cyclotron heating (ECH) and electron cyclotron current drive (ECCD) experiments. The antenna consists of a fast movable flat mirror mounted on the tokamak vacuum vessel and a rotary focusing mirror attached at the end of the waveguide that is supported from outside the vacuum vessel. This separate support concept enables a compact structure inside a shallow port (0.68x0.54x0.2 m) that is shared with a subport for an independent diagnostic system. During a plasma shot, the flat mirror is driven by a servomotor with a 3-m-long drive shaft to reduce the influence of the high magnetic field on the motor. The focusing mirror is rotated by a simple mechanism utilizing a push rod and an air cylinder. The antenna has been operated reliably for 3 years after a small improvement to the rotary drive mechanism. It has made significant contributions to ECH and ECCD experiments, especially the current profile control in JT-60U.

  10. Expanded study of feasibility of measuring in-flight 747/JT9D loads, performance, clearance, and thermal data

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.; Martin, R. L.

    1980-01-01

    The JT9D jet engine exhibits a TSFC loss of about 1 percent in the initial 50 flight cycles of a new engine. These early losses are caused by seal-wear induced opening of running clearances in the engine gas path. The causes of this seal wear have been identified as flight induced loads which deflect the engine cases and rotors, causing the rotating blades to rub against the seal surfaces, producing permanent clearance changes. The real level of flight loads encountered during airplane acceptance testing and revenue service and the engine's response in the dynamic flight environment were investigated. The feasibility of direct measurement of these flight loads and their effects by concurrent measurement of 747/JT9D propulsion system aerodynamic and inertia loads and the critical engine clearance and performance changes during 747 flight and ground operations was evaluated. A number of technical options were examined in relation to the total estimated program cost to facilitate selection of the most cost effective option. It is concluded that a flight test program meeting the overall objective of determining the levels of aerodynamic and inertia load levels to which the engine is exposed during the initial flight acceptance test and normal flight maneuvers is feasible and desirable. A specific recommended flight test program, based on the evaluation of cost effectiveness, is defined.

  11. Development of a closed-loop J-T cryoablation device with a long cooling area and multiple expansion parts.

    PubMed

    Lee, Cheonkyu; Baek, Seungwhan; Lee, Jisung; Hwang, Gyuwan; Jeong, Sangkwon; Park, Sang Woo

    2014-11-01

    Cryoablation is a surgical procedure used to freeze defective cells by inserting a low temperature probe into a human body to destroy malignant tissues. Miniaturized Joule-Thomson (J-T) refrigerators are often used to minimize the volume of the cooling device and reduce the destruction zone of normal tissue. The cooling effects of the existing probes are not uniformly generated along the longitudinal direction of the probe, which makes their applications less effective in surgeries of incompetent great saphenous veins (GSVs), where the target cells are distributed over a broad range. Long uniform refrigeration is required across the entire area of the probe to apply the same cooling effects. In this paper, a closed-loop J-T cryoablation probe was designed and fabricated to provide uniform refrigeration over a large area, with multiple expansion parts. Using flow boiling heat transfer, uniform cooling of a 200 mm-long and 0.3 mm thickness piece of target tissue was possible and simulated in a gelatin solution. The developed probe produced a greater than 53 K min(-1) cooling rate and the cooling temperature was below 253 K to satisfy the required cell death conditions.

  12. The 727 airplane side inlet low-speed performance confirmation model test for refanned JT8D engines

    NASA Technical Reports Server (NTRS)

    Schuehle, A. L.

    1974-01-01

    The results of a low-speed wind tunnel test of a 0.3 scale model 727 airplane side inlet for JT8D-100 engines are presented. The objectives of the test were to develop lines for a full-scale flightworthy inlet, to evaluate inlet total pressure recovery and steady-state total pressure distortion, and to obtain model-scale distortion data which can be used in the assessment of the compatibility of the inlet with the JT8D-100 series engines. A secondary objective was to obtain internal/external cowl static pressures for the determination of nacelle loads. Two basic inlet models were tested at static, forward speed, angle-of-attack (inflow angle), and cross-wind conditions. One model was with and one without an acoustic ring. Two modifications to the models were also tested, one with the ring closer to the inlet throat and one with a larger lip. Test measurements consisted of inlet surface static pressure, engine face total pressure, inlet airflow, tunnel total pressure, tunnel total temperature and tunnel velocity. Total pressure traverses were taken directly behind the ring and strut. No dynamic measurements were taken.

  13. Active Control of Inlet Noise on the JT15D Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Smith, Jerome P.; Hutcheson, Florence V.; Burdisso, Ricardo A.; Fuller, Chris R.

    1999-01-01

    This report presents the key results obtained by the Vibration and Acoustics Laboratories at Virginia Tech over the year from November 1997 to December 1998 on the Active Noise Control of Turbofan Engines research project funded by NASA Langley Research Center. The concept of implementing active noise control techniques with fuselage-mounted error sensors is investigated both analytically and experimentally. The analytical part of the project involves the continued development of an advanced modeling technique to provide prediction and design guidelines for application of active noise control techniques to large, realistic high bypass engines of the type on which active control methods are expected to be applied. Results from the advanced analytical model are presented that show the effectiveness of the control strategies, and the analytical results presented for fuselage error sensors show good agreement with the experimentally observed results and provide additional insight into the control phenomena. Additional analytical results are presented for active noise control used in conjunction with a wavenumber sensing technique. The experimental work is carried out on a running JT15D turbofan jet engine in a test stand at Virginia Tech. The control strategy used in these tests was the feedforward Filtered-X LMS algorithm. The control inputs were supplied by single and multiple circumferential arrays of acoustic sources equipped with neodymium iron cobalt magnets mounted upstream of the fan. The reference signal was obtained from an inlet mounted eddy current probe. The error signals were obtained from a number of pressure transducers flush-mounted in a simulated fuselage section mounted in the engine test cell. The active control methods are investigated when implemented with the control sources embedded within the acoustically absorptive material on a passively-lined inlet. The experimental results show that the combination of active control techniques with fuselage

  14. Comparison of several inflow control devices for flight simulation of fan tone noise using a JT15D-1 engine

    NASA Technical Reports Server (NTRS)

    Mcardle, J. G.; Jones, W. L.; Heidelberg, L. J.; Homyak, L.

    1980-01-01

    To enable accurate simulation of in-flight fan tone noise during ground static tests, four devices intended to reduce inflow disturbances and turbulence were tested with a JT15D-1 turbofan engine. These inflow control devices (ICD's) consisted of honeycomb/screen structures mounted over the engine inlet. The ICD's ranged from 1.6 to 4 fan diameters in size, and differed in shape and fabrication method. All the ICD's significantly reduced the BPF tone in the far-field directivity patterns, but the smallest ICD's apparently introduced propagating modes which could be recognized by additional lobes in the speeds; at supersonic fan tip speed the smallest ICD's had some measurable loss, but the largest had no loss. Data from a typical transducer show that the unsteady inflow distortion modes (turbulence) were eliminated or significantly reduced when either of the ICD's was installed. However, some steady inflow distortion modes remained.

  15. JT9D-70/59 Improved High Pressure Turbine Active Clearance Control System. [for specific fuel consumption improvement

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1979-01-01

    The JT9D-70/59 high pressure turbine active clearance control system was modified to provide reduction of blade tip clearance when the system is activated during cruise operation. The modification increased the flow capacity and air impingement effectiveness of the cooling air manifold to augment turbine case shrinkage capability, and increased responsiveness of the airseal clearance to case shrinkage. The simulated altitude engine testing indicated a significant improvement in specific fuel consumption with the modified system. A 1000 cycle engine endurance test showed no unusual wear or performance deterioration effects on the engine or the clearance control system. Rig tests indicated that the air impingement and seal support configurations used in the engine tests are near optimum.

  16. Conductor and joint test results of JT-60SA CS and EF coils using the NIFS test facility

    NASA Astrophysics Data System (ADS)

    Obana, Tetsuhiro; Takahata, Kazuya; Hamaguchi, Shinji; Kizu, Kaname; Murakami, Haruyuki; Chikaraishi, Hirotaka; Noguchi, Hiroki; Kobuchi, Takashi; Moriuchi, Sadatomo; Imagawa, Shinsaku; Mito, Toshiyuki; Tsuchiya, Katsuhiko; Natsume, Kyohei; Yoshida, Kiyoshi; Nomoto, Kazuhiro; Kim, Tae-hyun

    2016-01-01

    In 2007, JAEA and NIFS launched the test project to evaluate the performance of cable-in-conduit (CIC) conductors and conductor joints for the JT-60SA CS and EF coils. In this project, conductor tests for four types of coil conductor and joint tests for seven types of conductor joint have been conducted for the past eight years using the NIFS test facility. As a result, the test project indicated that the CIC conductors and conductor joints fulfill the design requirement for the CS and EF coils. In addition, the NIFS test facility is expected to be utilized as the test facility for the development of a conductor and conductor joint for the purpose of the DEMO nuclear fusion power plant, provided that the required magnetic field strength is within 9 T.

  17. Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1

    SciTech Connect

    Gupta, Prabhat Kumar; Rabehl, Roger

    2014-07-01

    Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.

  18. Investigation of performance deterioration of the CF6/JT9D, high-bypass ratio turbofan engines

    NASA Technical Reports Server (NTRS)

    Ziemianski, J. A.; Mehalic, C. M.

    1980-01-01

    The aircraft energy efficiency program within NASA is developing technology required to improve the fuel efficiency of commercial subsonic transport aricraft. One segment of this program includes engine diagnostics which is directed toward determining the sources and causes of performance deterioration in the Pratt and Whitney Aircraft JT9D and General Electric CF6 high-bypass ratio turbofan engines and developing technology for minimizing the performance losses. Results of engine performance deterioration investigations based on historical data, special engine tests, and specific tests to define the influence of flight loads and component clearances on performance are presented. The results of analysis of several damage mechanisms that contribute to performance deterioration such as blade tip rubs, airfoil surface roughness and erosion, and thermal distortion are also included. The significance of these damage mechanisms on component and overall engine performance is discussed.

  19. Results of tests of the X2274 high power tetrode in a JT-60 110 to 130 MHz ICRH amplifier

    SciTech Connect

    Remsen, D.B. ); Loring, C.M.; McNees, S.G. . EIMAC Div.); Moriyama, S.; Ogawa, Y.; Anno, K.; Fujii, T.; Terakado, M.; Kogure, S.; Nagashima, T.; Ohta, M. . Naka Fusion Research Establishment)

    1990-09-01

    This paper reports the results of tests of the newly developed Varian EIMAC X2274 in the JAERI JT-60 ICRH system at pulse lengths up to 6 seconds at 131 MHz. It is our belief that these tests achieved the highest long pulse, or CW, power that has ever been delivered by a single power grid tube at frequencies above 100 MHz. Varian's EIMAC X2274, developed in conjunction with General Atomics and the US Department of Energy, uses an improved pyrolytic graphite grid configuration which provides significantly better vhf performance than the grids of the X2242 tetrode which was tested in this system in 1989. The EIMAC X2274 combines the improved grids with a new anode design which reduces the required water flow approximately 50% and increases the maximum anode dissipation 80%. All tests were performed at 131 MHz, the system's highest operating frequency. Tests of both prototype EIMAC X2274s produced essentially identical results. The basic objectives of these tests were: to demonstrate that the system with the EIMAC X2274 can reliably produce 1.5 MW at 130 MHz at 5 second pulse lengths for the JT-60U tokamak and to collect data for use in the design of future high power ICRH systems. In these tests the tube and system produced up to 1.7 MW at pulse lengths up to 5.4 seconds: i.e, the EIMAC X2274 in this system can easily meet Objective 1. The remainder of this paper shows that Objective 2 has been fulfilled. In addition to the high power tests, operational range tests were performed under variable VSWR conditions. Unlike the EIMAC X2242 tests were rf current heating of the screen grid limited output power, system parameters, rather than tube parameters, limited the output power in the high power tests. Operational range tests were conducted at output power levels chosen to be well within the system's anode cooling capability.

  20. Design and testing of new center inlet and S-duct for B-727 airplane with refanned JT8D engines

    NASA Technical Reports Server (NTRS)

    Ting, C. T.; Kaldschmidt, G.; Syltebo, B. E.

    1975-01-01

    The work described in this paper was part of the NASA refan program. The airflow requirement of the refanned JT8D (-100 series) engine increased about 50% above that of the basic JT8D. This required a redesign of the center inlet and S-duct of the Boeing 727 airplane. The paper describes the design constraints for the S-duct and the analytic method used to define the lines of the new duct. Model tests that were conducted at static, angle-of-attack, and crosswind conditions are described with a variety of flow control devices. Test results showed that the new inlet and S-duct have a pressure recovery comparable to that of the existing inlet. By employing corotating vortex generators, less flow distortion was obtained for the core region than the existing duct has with its counter rotating vortex generators.

  1. Some comparisons of the flyover noise characteristics of DC-9 aircraft having refanned and hardwalled JT8D engines, with special reference to measurement and analysis procedures

    NASA Technical Reports Server (NTRS)

    Hosier, R. N.

    1976-01-01

    Flyover noise measurements were made (using Federal Aviation Regulations, part 36 procedures) of two DC-9 aircraft, one equipped with refanned JT8D-109 engines and the other equipped with hardwalled JT8D-9 engines. NASA analyses show a refan centerline noise reduction of about 9.1 EPNdB and 10.0 EPNdB for takeoff with cutback and 50 deg. flap landing approach, respectively. A comparison of refan and hardwall PNLTM spectra shows that the refan noise reduction may be attributed to lower jet noise levels on takeoff and reduced high-frequency tonal content on landing approach. A general description of the test procedures and results are included along with detailed descriptions of the measurement and analysis systems.

  2. Beamlet deflection due to beamlet-beamlet interaction in a large-area multiaperture negative ion source for JT-60U

    SciTech Connect

    Kamada, M.; Hanada, M.; Ikeda, Y.; Grisham, L. R.; Jiang, W.

    2008-02-15

    The JT-60U negative ion source has been designed to produce high current beams of 22 A through grids of 1080 apertures (five segments with nine rows of 24 apertures). One of the key issues is to steer such a high current beam through the multiaperture grids in order to focus the overall beam envelope because the beamlet-beamlet interaction may deflect the outer beamlets outward due to unbalanced space charge repulsion. To clarify the beam deflection in the JT-60U negative ion source, the beamlet trajectory in a multiaperture ion source was calculated by a three-dimensional simulation code. The measured angles of the outmost beamlets were in agreement with the calculated results where space charge of the beamlets was taken into account. It is noticed that the deflection of the outermost beamlet due to the beamlet-beamlet interaction is saturated at 5.2 mrad outward for beamlets more than ten.

  3. Phlogopite compositions as an indicator of both the geodynamic context of granitoids and the metallogeny aspect in Memve'ele Archean area, northwestern Congo craton

    NASA Astrophysics Data System (ADS)

    Ntomba, Sylvestre M.; Bidzang, François Ndong; Ottou, José Eric Messi; Goussi Ngalamo, François Jeannot; Bisso, Dieudonné; Magnekou Takamte, Christelle Rufine; Ondoa, Joseph Mvondo

    2016-06-01

    A barium bearing phlogopite (celsian) has been found for the first time within the charnockitic and tonalitic suites that compose Archean mineral belt in Cameroon. Electron microprobe analyses of these phlogopites are reported and contain moderate contents of BaO (0.42-1.26 wt. %) and up to 5.95 wt. % TiO2. Micas are Mg-rich and their compositions indicate phlogopites rich-meroxenes. Phlogopites from Memve'ele are characterized by a nearly horizontal trend of increasing total aluminium (2.494-2.931 a.p.f.u.) and relatively constant Fe/(Fe + Mg) suggesting contributions of aluminous supracrustal material to the magmas by anatexis or assimilation. Compositions of the barium titanium bearing phlogopite vary systematically according to rock types. It seems that the substitution scheme include Ba + Al + VI (Mg, Fe)2+ + 2 IVSi = K + Si + VITi + 2IVAl was dominant in the Memve'ele area thus, this scheme has made easy incorporation of Ba into phlogopite structure. The binary diagram of aluminium vs. titanium shows that phlogopites from the Memve'ele area have been formed by the same metasomatic mechanism as phlogopites from Canary Island xenoliths and Mezitler andesites but Ba enrichment of phlogopites from the Memve'ele area implies an early Ba-metasomatism contrary to those from Mezitler. The estimated temperature of the studied phlogopites indicated mainly two groups: (1) temperature range from 662 to 688 °C (average 676 °C) for phlogopite grains with High Mg# in the trondhjemite sample and (2) temperatures with interval limits from 757 to 800 °C (average 777.07 °C) for remnant phlogopites; reflecting primary and late crystallization respectively from slightly to highly oxidized magma (-17.30 to -13.87 Kbars). The geothermal gradient with average temperatures are 35.57-53.360 °C/Km and 30.95-46.42 °C/Km corresponding to 14.56-21.84 Km and 14.56-30.58 Km depth of below crust respectively. The crystallizing melt is enriched in Ba emanated from sea water at medium

  4. Aerodynamic performance of 0.4066-scale model of JT8D refan stage with S-duct inlet

    NASA Technical Reports Server (NTRS)

    Moore, R. D.; Kovich, G.; Lewis, G. W., Jr.

    1977-01-01

    A scale model of the JT8D refan stage was tested with a scale model of the S-duct inlet design for the refanned Boeing 727 center engine. Detailed survey data of pressures, temperatures, and flow angles were obtained over a range of flows at speeds from 70 to 97 percent of design speed. Two S-duct configurations were tested; one with a bellmouth inlet and the other with a flight lip inlet. The results indicated that the overall performance was essentially unaffected by the distortion generated by the S-duct inlet. The stall weight flow increased by less than 0.5 kg/sec (approximately 1.5% of design flow) with the S-duct inlet compared with that obtained with uniform flow. The detailed measurements indicated that the inlet guide vane (IGV) significantly reduced circumferential variations. For example, the flow angles ahead of the IGV were positive in the right half of the inlet and negative in the left half. Behind the IGV, the flow angles tended to be more uniform circumferentially.

  5. Titanium honeycomb acoustic lining structural and thermal test report. [for acoustic tailpipe for JT8D engine

    NASA Technical Reports Server (NTRS)

    Joynes, D.; Balut, J. P.

    1974-01-01

    The results are presented of static, fatigue and thermal testing of titanium honeycomb acoustic panels representing the acoustic tailpipe for the Pratt and Whitney Aircraft JT8D Refan engine which is being studied for use on the Boeing 727-200 airplane. Test specimens represented the engine and tailpipe flange joints, the rail to which the thrust reverser is attached and shear specimens of the tailpipe honeycomb. Specimens were made in four different batches with variations in configuration, materials and processes in each. Static strength of all test specimens exceeded the design ultimate load requirements. Fatigue test results confirmed that aluminum brazed titanium, as used in the Refan tailpipe design, meets the fatigue durability objectives. Quality of welding was found to be critical to life, with substandard welding failing prematurely, whereas welding within the process specification exceeded the panel skin life. Initial fatigue testing used short grip length bolts which failed prematurely. These were replaced with longer bolts and subsequent testing demonstrated the required life. Thermal tests indicate that perforated skin acoustic honeycomb has approximately twice the heat transfer of solid skin honeycomb.

  6. Validation studies of gyrokinetic ITG and TEM turbulence simulations in a JT-60U tokamak using multiple flux matching

    NASA Astrophysics Data System (ADS)

    Nakata, Motoki; Honda, Mitsuru; Yoshida, Maiko; Urano, Hajime; Nunami, Masanori; Maeyama, Shinya; Watanabe, Tomo-Hiko; Sugama, Hideo

    2016-08-01

    Quantitative validation studies of flux-tube gyrokinetic Vlasov simulations on ion and electron heat transport are carried out for the JT-60U tokamak experiment. The ion temperature gradient (ITG) and/or trapped electron modes (TEM) driven turbulent transport and zonal flow generations are investigated for an L-mode plasma in the local turbulence limit with a sufficiently small normalized ion thermal gyroradius and weak mean radial electric fields. Nonlinear turbulence simulations by the GKV code successfully reproduce radial profiles of the ion and electron energy fluxes in the core region. The numerical results show that the TEM-driven zonal flow generation in the outer region is more significant than that in the core region with ITG- and ITG–TEM-dominated turbulence, leading to moderate transport shortfall of the ion energy flux. Error levels in the prediction of the ion and electron temperature gradient profiles in the core region are estimated as less than +/- 30% , based on a multiple flux matching technique, where the simulated ion and electron energy fluxes are simultaneously matched to the experimental values.

  7. Validation studies of gyrokinetic ITG and TEM turbulence simulations in a JT-60U tokamak using multiple flux matching

    NASA Astrophysics Data System (ADS)

    Nakata, Motoki; Honda, Mitsuru; Yoshida, Maiko; Urano, Hajime; Nunami, Masanori; Maeyama, Shinya; Watanabe, Tomo-Hiko; Sugama, Hideo

    2016-08-01

    Quantitative validation studies of flux-tube gyrokinetic Vlasov simulations on ion and electron heat transport are carried out for the JT-60U tokamak experiment. The ion temperature gradient (ITG) and/or trapped electron modes (TEM) driven turbulent transport and zonal flow generations are investigated for an L-mode plasma in the local turbulence limit with a sufficiently small normalized ion thermal gyroradius and weak mean radial electric fields. Nonlinear turbulence simulations by the GKV code successfully reproduce radial profiles of the ion and electron energy fluxes in the core region. The numerical results show that the TEM-driven zonal flow generation in the outer region is more significant than that in the core region with ITG- and ITG-TEM-dominated turbulence, leading to moderate transport shortfall of the ion energy flux. Error levels in the prediction of the ion and electron temperature gradient profiles in the core region are estimated as less than +/- 30% , based on a multiple flux matching technique, where the simulated ion and electron energy fluxes are simultaneously matched to the experimental values.

  8. Surface discharge related properties of fiberglass reinforced plastic insulator for use in neutral beam injector of JT-60U

    SciTech Connect

    Yamano, Y.; Takahashi, M.; Kobayashi, S.; Hanada, M.; Ikeda, Y.

    2008-02-15

    Neutral beam injection (NBI) used for JT-60U is required to generate negative ions of 500 keV energies. To produce such high-energy ions, three-stage electrostatic accelerators consisting of three insulator rings made of fiberglass reinforced plastic (FRP) are applied. The surface discharges along FRP insulators are one of the most serious problems in the development of NBI. To increase the hold-off voltage against surface flashover events, it is necessary to investigate the FRP insulator properties related to surface discharges in vacuum. This paper describes surface flashover characteristics for FRP and alumina samples under vacuum condition. The results show that the fold-off voltages for FRP samples are inferior to those of alumina ceramics. In addition, measurement results of surface resistivity and volume resistivity under vacuum and atmospheric conditions, secondary electron emission characteristics, and cathodoluminescence under some keV electron beam irradiation are also reported. These are important parameters to analyze surface discharge of insulators in vacuum.

  9. Surface discharge related properties of fiberglass reinforced plastic insulator for use in neutral beam injector of JT-60U.

    PubMed

    Yamano, Y; Takahashi, M; Kobayashi, S; Hanada, M; Ikeda, Y

    2008-02-01

    Neutral beam injection (NBI) used for JT-60U is required to generate negative ions of 500 keV energies. To produce such high-energy ions, three-stage electrostatic accelerators consisting of three insulator rings made of fiberglass reinforced plastic (FRP) are applied. The surface discharges along FRP insulators are one of the most serious problems in the development of NBI. To increase the hold-off voltage against surface flashover events, it is necessary to investigate the FRP insulator properties related to surface discharges in vacuum. This paper describes surface flashover characteristics for FRP and alumina samples under vacuum condition. The results show that the fold-off voltages for FRP samples are inferior to those of alumina ceramics. In addition, measurement results of surface resistivity and volume resistivity under vacuum and atmospheric conditions, secondary electron emission characteristics, and cathodoluminescence under some keV electron beam irradiation are also reported. These are important parameters to analyze surface discharge of insulators in vacuum.

  10. Long-pulse production of high current negative ion beam by using actively temperature controlled plasma grid for JT-60SA negative ion source

    SciTech Connect

    Kojima, A.; Hanada, M.; Yoshida, M.; Umeda, N.; Hiratsuka, J.; Kashiwagi, M.; Tobari, H.; Watanabe, K.; Grisham, L. R.

    2015-04-08

    The temperature control system of the large-size plasma grid has been developed to realize the long pulse production of high-current negative ions for JT-60SA. By using this prototype system for the JT-60SA ion source, 15 A negative ions has been sustained for 100 s for the first time, which is three times longer than that obtained in JT-60U. In this system, a high-temperature fluorinated fluid with a high boiling point of 270 degree Celsius is circulated in the cooling channels of the plasma grids (PG) where a cesium (Cs) coverage is formed to enhance the negative ion production. Because the PG temperature control had been applied to only 10% of the extraction area previously, the prototype PG with the full extraction area (110 cm × 45 cm) was developed to increase the negative ion current in this time. In the preliminary results of long pulse productions of high-current negative ions at a Cs conditioning phase, the negative ion production was gradually degraded in the last half of 100 s pulse where the temperature of an arc chamber wall was not saturated. From the spectroscopic measurements, it was found that the Cs flux released from the wall might affect to the negative ion production, which implied the wall temperature should be kept low to control the Cs flux to the PG for the long-pulse high-current production. The obtained results of long-pulse production and the PG temperature control method contributes the design of the ITER ion source.

  11. Phase 2 program on ground test of refanned JT8D turbofan engines and nacelles for the 727 airplane. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The propulsion performance, acoustic, structural, and systems changes to a 727-200 airplane retrofitted with a refan modification of the JT8D turbofan engine are evaluated. Model tests, design of certifiable airplane retrofit kit hardware, manufacture of test hardware, ground test of a current production JT8D engine, followed by test of the same engine modified to the refan configuration, detailed analyses of the retrofit impact on airplane airworthiness, performance, and noise, and a preliminary analysis of retrofit costs are included. Results indicate that the refan retrofit of the 727-200 would be certifiable and would result in a 6-to 8 EPNdb reduction in effective perceived noise level (EPNL) at the FAR 36 measuring points and an annoyance-weighted footprint area reduction of 68% to 83%. The installed refan engine is estimated to provide 14% greater takeoff thrust at zero velocity and 10% greater thrust at 100 kn (51.4 m/s). There would be an approximate 0.6% increase in cruise specific fuel consumption (SFC). The refan engine performance in conjunction with the increase in stalled weight results in a range reduction of approximately 15% over the unmodified airplane at the same brake release gross weight (BRGW), with a block fuel increase of 1.5% to 3%. With the particular model 727 that was studied, however, it is possible to operate the airplane (with minor structural modifications) at a higher BRGW and increase the range up to approximately 15% relative to the nonrefanned airplane (with equal or slightly increased noise levels). The JT8D refan engine also improves the limited-field range of the airplane.

  12. Optical designs of reflection and refraction collection optics for a JT-60SA core Thomson scattering system

    SciTech Connect

    Tojo, H.; Hatae, T.; Hamano, T.; Sakuma, T.; Itami, K.

    2013-09-15

    Collection optics for core measurements in a JT-60SA Thomson scattering system were designed. The collection optics will be installed in a limited space and have a wide field of view and wide wavelength range. Two types of the optics are therefore suggested: refraction and reflection types. The reflection system, with a large primary mirror, avoids large chromatic aberrations. Because the size limit of the primary mirror and vignetting due to the secondary mirror affect the total collection throughput, conditions that provide the high throughput are found through an optimization. A refraction system with four lenses forming an Ernostar system is also employed. The use of high-refractive-index glass materials enhances the freedom of the lens curvatures, resulting in suppression of the spherical and coma aberration. Moreover, sufficient throughput can be achieved, even with smaller lenses than that of a previous design given in [H. Tojo, T. Hatae, T. Sakuma, T. Hamano, K. Itami, Y. Aida, S. Suitoh, and D. Fujie, Rev. Sci. Instrum. 81, 10D539 (2010)]. The optical resolutions of the reflection and refraction systems are both sufficient for understanding the spatial structures in plasma. In particular, the spot sizes at the image of the optics are evaluated as ∼0.3 mm and ∼0.4 mm, respectively. The throughput for the two systems, including the pupil size and transmissivity, are also compared. The results show that good measurement accuracy (<10%) even at high electron temperatures (<30 keV) can be expected in the refraction system.

  13. Cruise Drag Results from High Speed Wind Tunnel Tests of NASA Refan JT8D Engine Nacelles on the Boeing 727-200

    NASA Technical Reports Server (NTRS)

    Easterbrook, W. G.; Carlson, R. B.

    1973-01-01

    High speed wind tunnel test results are presented showing the cruise drag effect of installing JT8D-109 Refan engines on a Boeing 727-200. Incremental drags of a refan center inlet and side nacelles are presented for several configuration variations. Static pressure distributions were obtained on the side nacelle strut and on the fuselage (above and below the strut). Oil flow photographs of selected configurations are also presented. In general the drag level of the refan installation is slightly better than predicted prior to the test and the drag rise is favorable.

  14. Design and development of a four-cell sorption compressor based J-T cooler using R134a as working fluid

    NASA Astrophysics Data System (ADS)

    Mehta, R. N.; Bapat, S. L.; Atrey, M. D.

    2014-01-01

    The need of a cooler with no electromagnetic interference and practically zero vibration has led to sorption compressor based Joule-Thomson (J-T) coolers. These are useful for sophisticated electronic, ground based and space borne systems. In a Sorption compressor, adsorbed gases are desorbed into a confined volume by raising temperature of the sorption bed resulting in an increase in pressure of the liberated gas. In order to have the system (compressor) functioning on a continuous basis, with almost a constant gas flow rate, multiple cells are used with the adaptation of Temperature Swing Adsorption (TSA) process. As the mass of the desorbed gas dictates the compressor throughput, a combination of sorbent material with high adsorption capacity for a chosen gas or gas mixture has to be selected for efficient operation of the compressor. Commercially available (coconut-shell base) activated carbon has been selected for the present application. The characterization study for variation of discharge pressure is used to design the Four-cell sorption compressor based cryocooler with a desired output. Apart from compressor, the system includes a) After cooler b) Return gas heat exchanger c) capillary tube as the J-T expansion device and d) Evaporator.

  15. Design and development of a four-cell sorption compressor based J-T cooler using R134a as working fluid

    SciTech Connect

    Mehta, R. N.; Bapat, S. L.; Atrey, M. D.

    2014-01-29

    The need of a cooler with no electromagnetic interference and practically zero vibration has led to sorption compressor based Joule-Thomson (J-T) coolers. These are useful for sophisticated electronic, ground based and space borne systems. In a Sorption compressor, adsorbed gases are desorbed into a confined volume by raising temperature of the sorption bed resulting in an increase in pressure of the liberated gas. In order to have the system (compressor) functioning on a continuous basis, with almost a constant gas flow rate, multiple cells are used with the adaptation of Temperature Swing Adsorption (TSA) process. As the mass of the desorbed gas dictates the compressor throughput, a combination of sorbent material with high adsorption capacity for a chosen gas or gas mixture has to be selected for efficient operation of the compressor. Commercially available (coconut-shell base) activated carbon has been selected for the present application. The characterization study for variation of discharge pressure is used to design the Four-cell sorption compressor based cryocooler with a desired output. Apart from compressor, the system includes a) After cooler b) Return gas heat exchanger c) capillary tube as the J-T expansion device and d) Evaporator.

  16. Dynamics of energetic particle driven modes and MHD modes in wall-stabilized high-β plasmas on JT-60U and DIII-D

    NASA Astrophysics Data System (ADS)

    Matsunaga, G.; Okabayashi, M.; Aiba, N.; Boedo, J. A.; Ferron, J. R.; Hanson, J. M.; Hao, G. Z.; Heidbrink, W. W.; Holcomb, C. T.; In, Y.; Jackson, G. L.; Liu, Y. Q.; Luce, T. C.; McKee, G. R.; Osborne, T. H.; Pace, D. C.; Shinohara, K.; Snyder, P. B.; Solomon, W. M.; Strait, E. J.; Turnbull, A. D.; Van Zeeland, M. A.; Watkins, J. G.; Zeng, L.; the DIII-D Team; the JT-60 Team

    2013-12-01

    In the wall-stabilized high-β plasmas in JT-60U and DIII-D, interactions between energetic particle (EP) driven modes (EPdMs) and edge localized modes (ELMs) have been observed. The interaction between the EPdM and ELM are reproducibly observed. Many EP diagnostics indicate a strong correlation between the distorted waveform of the EPdM and the EP transport to the edge. The waveform distortion is composed of higher harmonics (n ⩾ 2) and looks like a density snake near the plasma edge. According to statistical analyses, ELM triggering by the EPdMs requires a finite level of waveform distortion and pedestal recovery. ELM pacing by the EPdMs occurs when the repetition frequency of the EPdMs is higher than the natural ELM frequency. EPs transported by EPdMs are thought to contribute to change the edge stability.

  17. Improvement of uniformity of the negative ion beams by tent-shaped magnetic field in the JT-60 negative ion source

    SciTech Connect

    Yoshida, Masafumi Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; Ohzeki, Masahiro; Seki, Norikazu; Sasaki, Shunichi; Shimizu, Tatsuo; Terunuma, Yuto; Grisham, Larry R.

    2014-02-15

    Non-uniformity of the negative ion beams in the JT-60 negative ion source with the world-largest ion extraction area was improved by modifying the magnetic filter in the source from the plasma grid (PG) filter to a tent-shaped filter. The magnetic design via electron trajectory calculation showed that the tent-shaped filter was expected to suppress the localization of the primary electrons emitted from the filaments and created uniform plasma with positive ions and atoms of the parent particles for the negative ions. By modifying the magnetic filter to the tent-shaped filter, the uniformity defined as the deviation from the averaged beam intensity was reduced from 14% of the PG filter to ∼10% without a reduction of the negative ion production.

  18. Effect of resistivity profile on current decay time of initial phase of current quench in neon-gas-puff inducing disruptions of JT-60U

    SciTech Connect

    Kawakami, S.; Ohno, N.; Shibata, Y.; Isayama, A.; Kawano, Y.; Watanabe, K. Y.; Takizuka, T.; Okamoto, M.

    2013-11-15

    According to an early work [Y. Shibata et al., Nucl. Fusion 50, 025015 (2010)] on the behavior of the plasma current decay in the JT-60U disruptive discharges caused by the radiative collapse with a massive neon-gas-puff, the increase of the internal inductance mainly determined the current decay time of plasma current during the initial phase of current quench. To investigate what determines the increase of the internal inductance, we focus attention on the relationship between the electron temperature (or the resistivity) profile and the time evolution of the current density profile and carry out numerical calculations. As a result, we find the reason of the increase of the internal inductance: The current density profile at the start of the current quench is broader than an expected current density profile in the steady state, which is determined by the temperature (or resistivity) profile. The current density profile evolves into peaked one and the internal inductance is increasing.

  19. DC-9/JT8D refan, Phase 1. [technical and economic feasibility of retrofitting DC-9 aircraft with refan engine to achieve desired acoustic levels

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Analyses and design studies were conducted on the technical and economic feasibility of installing the JT8D-109 refan engine on the DC-9 aircraft. Design criteria included minimum change to the airframe to achieve desired acoustic levels. Several acoustic configurations were studied with two selected for detailed investigations. The minimum selected acoustic treatment configuration results in an estimated aircraft weight increase of 608 kg (1,342 lb) and the maximum selected acoustic treatment configuration results in an estimated aircraft weight increase of 809 kg (1,784 lb). The range loss for the minimum and maximum selected acoustic treatment configurations based on long range cruise at 10 668 m (35,000 ft) altitude with a typical payload of 6 804 kg (15,000 lb) amounts to 54 km (86 n. mi.) respectively. Estimated reduction in EPNL's for minimum selected treatment show 8 EPNdB at approach, 12 EPNdB for takeoff with power cutback, 15 EPNdB for takeoff without power cutback and 12 EPNdB for sideline using FAR Part 36. Little difference was estimated in EPNL between minimum and maximum treatments due to reduced performance of maximum treatment. No major technical problems were encountered in the study. The refan concept for the DC-9 appears technically feasible and economically viable at approximately $1,000,000 per airplane. An additional study of the installation of JT3D-9 refan engine on the DC-8-50/61 and DC-8-62/63 aircraft is included. Three levels of acoustic treatment were suggested for DC-8-50/61 and two levels for DC-8-62/63. Results indicate the DC-8 technically can be retrofitted with refan engines for approximately $2,500,000 per airplane.

  20. Off-axis fishbone-like instability and excitation of resistive wall modes in JT-60U and DIII-D

    SciTech Connect

    Okabayashi, M.; Solomon, W. M.; Budny, R. V.; Manickam, J.; Matsunaga, G.; Takechi, M.; Asakura, N.; Shinohara, K.; Grassie, J. S. de; Strait, E. J.; Jackson, G. L.; La Haye, R. J.; Heidbrink, W. W.; Zhu, Y. B.; In, Y.; Liu, Y. Q.

    2011-05-15

    An energetic-particle (EP)-driven ''off-axis-fishbone-like mode (OFM)'' often triggers a resistive wall mode (RWM) in JT-60U and DIII-D devices, preventing long-duration high-{beta}{sub N} discharges. In these experiments, the EPs are energetic ions (70-85 keV) injected by neutral beams to produce high-pressure plasmas. EP-driven bursting events reduce the EP density and the plasma rotation simultaneously. These changes are significant in high-{beta}{sub N} low-rotation plasmas, where the RWM stability is predicted to be strongly influenced by the EP precession drift resonance and by the plasma rotation near the q=2 surface (kinetic effects). Analysis of these effects on stability with a self-consistent perturbation to the mode structure using the MARS-K code showed that the impact of EP losses and rotation drop is sufficient to destabilize the RWM in low-rotation plasmas, when the plasma rotation normalized by Alfven frequency is only a few tenths of a percent near the q=2 surface. The OFM characteristics are very similar in JT-60U and DIII-D, including nonlinear mode evolution. The modes grow initially like a classical fishbone, and then the mode structure becomes strongly distorted. The dynamic response of the OFM to an applied n=1 external field indicates that the mode retains its external kink character. These comparative studies suggest that an energetic particle-driven 'off-axis-fishbone-like mode' is a new EP-driven branch of the external kink mode in wall-stabilized plasmas, analogous to the relationship of the classical fishbone branch to the internal kink mode.

  1. Development of a high-brightness and low-divergence lithium neutral beam for a Zeeman polarimetry on JT-60U.

    PubMed

    Kojima, Atshushi; Kamiya, Kensaku; Iguchi, Harukazu; Fujita, Takaaki; Kakiuchi, Hideto; Kamada, Yutaka

    2008-09-01

    A high-brightness and low-divergence neutral beam is obtained for a Zeeman polarimetry of edge plasmas on JT-60U. The electron density and the pitch angle of the magnetic field line, thus the plasma current density distribution, can be measured by the Zeeman polarimetry using the lithium beam. A thermionic ion source heated by an electron beam is developed in order to obtain the ion beam current extraction over 10 mA. The beam optics is designed after detailed numerical simulation taking the space charge effects into account because a low-divergence angle of the neutral lithium beam leads to a narrow spectrum of the beam emission. It is also necessary to keep the beam radius small for good spatial resolution due to a long beam line of 6.5 m. The newly developed ion gun is operated on a test stand which simulates the diagnostic arrangement on JT-60U. The ion beam current of 10 mA at a beam energy of 10 keV is successfully extracted from the ion source operated at the temperature over 1300 degrees C and focused by Einzel lens. The full width at half maximum radius of the ion beam at the neutralizer is about 9 mm. A sodium vapor neutralizer neutralizes the collimated ion beam fully at the temperature of 300 degrees C. The neutral beam profiles are measured at two locations of the beam line at Z=2.3 m (beam monitor position) and Z=6.5 m (plasma region). The half-width at half maximum radius of the neutral beam of 26 mm and the equivalent beam current of 3 mA with the beam divergence angle of 0.2 deg which is the half-angle divergence are obtained. Those parameters satisfy the requirements of the Zeeman polarimetry. Furthermore, a long pulse extraction with a current of 10 mA and duration of 50 s is attained.

  2. Flight effects on noise generated by the JT8D-17 engine in a quiet nacelle and a conventional nacelle as measured in the NASA-Ames 40- by 80-foot wind tunnel

    NASA Technical Reports Server (NTRS)

    Strout, F. G.

    1976-01-01

    A JT8D-17 turbofan engine was tested in the NASA-Ames 40- by 80-foot wind tunnel to determine flight effects on jet and fan noise. Baseline, quiet nacelle with 20-lobe ejector/suppressor, and internal mixer configurations were tested over a range of engine power settings and tunnel velocities. Flight effects derived from the 40- by 80-foot wind tunnel test are compared with 727/JT8D flight test data and with model data obtained in a smaller wind tunnel. Procedures are defined for measuring noise data in a wind tunnel relatively near the sources and analyzing the results to obtain far-field flight effects. Wind tunnel and 727 flight test noise results compare favorably for both the baseline and quiet nacelle configurations. Two reports are provided, including a comprehensive version with extensive test results and analysis and the subject summary version that emphasizes data analysis and program finding.

  3. Flight effects on noise by the JT8D engine with inverted primary/fan flow as measured in the NASA-Ames 40 by 80 foot wind tunnel

    NASA Technical Reports Server (NTRS)

    Strout, F. G.

    1978-01-01

    A JT8D-17R engine with inverted primary and fan flows was tested under static conditions as well as in the NASA Ames 40 by 80 Foot Wind Tunnel to determine static and flight noise characteristics, and flow profile of a large scale engine. Test and analysis techniques developed by a previous model and JT8D engine test program were used to determine the in-flight noise. The engine with inverted flow was tested with a conical nozzle and with a plug nozzle, 20 lobe nozzle, and an acoustic shield. Wind tunnel results show that forward velocity causes significant reduction in peak PNL suppression relative to uninverted flow. The loss of EPNL suppression is relatively modest. The in-flight peak PNL suppression of the inverter with conical nozzle was 2.5 PNdb relative to a static value of 5.5 PNdb. The corresponding EPNL suppression was 4.0 EPNdb for flight and 5.0 EPNdb for static operation. The highest in-flight EPNL suppression was 7.5 EPNdb obtained by the inverter with 20 lobe nozzle and acoustic shield. When compared with the JT8D engine with internal mixer, the inverted flow configuration provides more EPNL suppression under both static and flight conditions.

  4. Thermal-hydraulic analysis of transients in the HELIOS loop including a CICC section representative of the JT-60SA Central Solenoid

    NASA Astrophysics Data System (ADS)

    Carli, S.; Bonifetto, R.; Hoa, C.; Savoldi, L.; Zanino, R.

    2015-12-01

    The HELIOS facility at CEA Grenoble is a supercritical helium (SHe) loop which is being used to investigate the effects on the cryogenic cooling system of the pulsed heat loads which are typical of superconducting tokamak operation. In the standard configuration, the magnet heat load is simulated by electrical heaters wrapped around a section of cryoline. In the present work, the resistively heated section is substituted in the HELIOS model of the 4C code, already validated for the standard configuration of HELIOS, by a sub-size winding structure made of JT-60SA Cable-In-Conduit Conductors (CICCs). The new model is then used to highlight the differences in the circuit behaviour when the heated pipe is substituted by an actual magnet wound with CICCs, checking the representativeness of the control strategies developed for the present HELIOS configuration. The use of CICCs will be shown to produce an intrinsic smoothing of the temperature profiles which is not affecting the capability of the control strategies to smooth the heat loads to the cryoplant.

  5. Phase 2 program on ground test of refanned JT8D turbofan engines and nacelles for the 727 airplane. Volume 4: Airplane evaluation and analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The retrofit of JT8D-109 (refan) engines are evaluated on a 727-200 airplane in terms of airworthiness, performance, and noise. Design of certifiable hardware, manufacture, and ground testing of the essential nacelle components is included along with analysis of the certifiable airplane design to ensure airworthiness compliance and to predict the in-flight performance and noise characteristics of the modified airplane. The analyses confirm that the 727 refan airplane is certifiable. The refan airplane range would be 15% less that of the baseline airplane and block fuel would be increased by 1.5% to 3%. However, with this particular 727-200 model, with a brake release gross weight of 172,500 lb (78,245 kg), it is possible to operate the airplane (with minor structural modifications) at higher gross weights and increase the range up to 15% over the 727-200 (baseline) airplane. The refan airplane FAR Part 36 noise levels would be 6 to 8 EPNdB (effective perceived noise in decibels) below the baseline. Noise footprint studies showed that approach noise contour areas are small compared to takeoff areas. The 727 refan realizes a 68% to 83% reduction in annoyance-weighted area when compared to the 727-200 over a range of gross weights and operational procedures.

  6. Flight effects on JT8D engine jet noise as measured in the NASA Ames 40-by 80-foot wind tunnel

    NASA Technical Reports Server (NTRS)

    Strout, F. G.; Atencio, A., Jr.

    1976-01-01

    A JT8D-17 turbofan engine was tested in a 40 x 80 ft wind tunnel to determine flight effects on jet noise. The engine was configured as a baseline with conical nozzle, a quiet nacelle 20-lobe ejector/suppressor, and an internal mixer with conical nozzle. Tunnel-off and tunnel-on noise tests were conducted over a range of nozzle pressure ratios (1.2 to 2.1), primary jet velocities (275 to 550 m/s), and tunnel velocities up to 100 m/s. Aft quadrant noise data were measured by a pair of traversing microphones located on a 3-m sideline relative to the engine centerline. Unique correlations and analysis procedures were developed in order to define far-field flight effects from the relatively near-field noise measurements. The ejector/suppressor experienced a significant loss of suppression relative to static measurements during flight while the internal mixer indicated a slight gain in suppression. It is concluded that the wind tunnel is a viable method for studying flight effects on engine jet noise.

  7. Recent RF Experiments and Application of RF Waves to Real-Time Control of Safety Factor Profile in JT-60U

    SciTech Connect

    Suzuki, T.; Isayama, A.; Ide, S.; Fujita, T.; Oikawa, T.; Sakata, S.; Sueoka, M.; Hosoyama, H.; Seki, M.

    2005-09-26

    Two topics of applications of RF waves to current profile control in JT-60U are presented; application of lower-hybrid (LH) waves to safety factor profile control and electron cyclotron (EC) waves to neo-classical tearing mode (NTM) control. A real-time control system of safety factor (q) profile was developed. This system, for the first time, enables 1) real time evaluation of q profile using local magnetic pitch angle measurement by motional Stark effect (MSE) diagnostic and 2) control of current drive (CD) location ({rho}CD) by controlling the parallel refractive index N parallel of LH waves through control of phase difference ({delta}{phi}) of LH waves between multi-junction launcher modules. The method for real-time q profile evaluation was newly developed, without time-consuming reconstruction of equilibrium, so that the method requires less computational time. Safety factor profile by the real-time calculation agrees well with that by equilibrium reconstruction with MSE. The control system controls {rho}CD through {delta}{phi} in such a way to decrease the largest residual between the real-time evaluated q profile q(r) and its reference profile qref(r). The real-time control system was applied to a positive shear plasma (q(0){approx}1). The reference q profile was set to monotonic positive shear profile having qref(0)=1.3. The real-time q profile approached to the qref(r) during application of real-time control, and was sustained for 3s, which was limited by the duration of the injected LH power. Temporal evolution of current profile was consistent with relaxation of inductive electric field induced by theoretical LH driven current. An m/n=3/2 NTM that appeared at {beta}N{approx}3 was completely stabilized by ECCD applied to a fully-developed NTM. Precise ECCD at NTM island was essential for the stabilization. ECCD that was applied to resonant rational surface (q=3/2) before an NTM onset suppressed appearance of NTM. In order to keep NTM intensity below a

  8. The results of a high-speed wind tunnel test to investigate the effects of the NASA refan JT8D engine nacelles on the stability and control characteristics of the Boeing 727 airplane

    NASA Technical Reports Server (NTRS)

    Kupcis, E. A.

    1973-01-01

    A high speed wind tunnel test was conducted to investigate the effects of the NASA Refan JT8D engine nacelles on the stability and control characteristics of the Boeing 727 airplane. The test was performed at the Calspan Corporation 8x8 ft. (2.44x2.44 m.) transonic wind tunnel. Both the 727-200 and -100 models were tested. A small nose-down pitching moment increment and a slight increase in longitudinal stability were noted due to the Refan nacelles. The directional stability of the 727-200 airplane increased up to 10 percent. A smaller improvement was observed on the 727-100 model. In general, the high speed stability and control characteristics of the basic airplane are not significantly altered by the Refan nacelle installation.

  9. The results of a low-speed wind tunnel test to investigate the effects of the Refan JT8D engine target thrust reverser on the stability and control characteristics of the Boeing 727-200 airplane

    NASA Technical Reports Server (NTRS)

    Kupcis, E. A.

    1974-01-01

    The effects of the Refan JT8D side engine target thrust reverser on the stability and control characteristics of the Boeing 727-200 airplane were investigated using the Boeing-Vertol 20 x 20 ft Low-Speed Wind Tunnel. A powered model of the 727-200 was tested in groud effect in the landing configuration. The Refan target reverser configuration was evaluated relative to the basic production 727 airplane with its clamshell-deflector door thrust reverser design. The Refan configuration had slightly improved directional control characteristics relative to the basic airplane. Clocking the Refan thrust reversers 20 degrees outboard to direct the reverser flow away from the vertical tail, had little effect on directional control. However, clocking them 20 degrees inboard resulted in a complete loss of rudder effectiveness for speeds greater than 90 knots. Variations in Refan reverser lip/fence geometry had a minor effect on directional control.

  10. The emission rates of CH, CD and C2 spectral bands and a re-evaluation of the chemical sputtering yield of the JT-60U carbon divertor plates

    NASA Astrophysics Data System (ADS)

    Nakano, T.; Higashijima, S.; Kubo, H.; Asakura, N.; Fukumoto, M.

    2014-04-01

    The CH photon emission rate, defined as the number of photons over a dissociation and/or ionization event of CH4, has been determined from the ratio of the measured emission intensity of the CH spectral band over the CH4 injection rate into the divertor plasma of JT-60U. Similar photon emission rates of CD for CD4, and CH and C2 for C2H4 and C2H6, have also been determined. Interestingly, the C2 spectral band intensity is found to increase during the CH4 and CD4 injection, suggesting that the injected CH4 reacts with the carbon divertor plates to form heavier hydrocarbons. Previously published chemical sputtering yields (Nakano et al 2002 Nucl. Fusion 42 689) evaluated with the photon efficiencies determined in PISCES-A (Pospieszczyk et al 1989 UCLA Report UCLA-PPG-1251) have been re-evaluated using the measured emission rates. By applying the photon emission data found here and taking into account the C2 emission process originating from CH4, the re-evaluated total chemical sputtering yield becomes lower (˜7%) compared to the original in (Nakano et al 2002 Nucl. Fusion 42 689) (˜8%), and the dependence on the incident ion flux and energy becomes weaker.

  11. Triton burnup study in JT-60U

    SciTech Connect

    Nishitani, T.; Hoek, M.; Isobe, M.; Tobita, K.; Kusama, Y.; Harano, H.; Wurden, G.A.; Chrien, R.E.

    1995-10-01

    The behavior of 1 MeV tritons produced in the d(d,p)t reaction is important to predict the properties of D-T produced 3.5 MeV alphas because 1 MeV tritons and 3.5 MeV alphas have similar kinematic properties, such as Larmor radius and precession frequency. The confinement and slowing down of the fast tritons were investigated by measuring the 14 MeV and the 2.5 MeV neutron production rates. Here the time resolved triton burnup measurements have been performed using a new type 14 MeV neutron detector based on scintillating fibers, as part of a US-Japan tokamak collaboration. Loss of alpha particles due to toroidal ripple is one of the most important issues to be solved for a fusion reactor such as ITER. The authors investigated the toroidal ripple effect on the fast triton by analyzing the time history of the 14 MeV emission after NB turn-off.

  12. JT90 thermal barrier coated vanes

    NASA Technical Reports Server (NTRS)

    Sheffler, K. D.; Graziani, R. A.; Sinko, G. C.

    1982-01-01

    The technology of plasma sprayed thermal barrier coatings applied to turbine vane platforms in modern high temperature commercial engines was advanced to the point of demonstrated feasibility for application to commercial aircraft engines. The three thermal barrier coatings refined under this program are zirconia stabilized with twenty-one percent magnesia (21% MSZ), six percent yttria (6% YSZ), and twenty percent yttria (20% YSZ). Improvement in thermal cyclic endurance by a factor of 40 times was demonstrated in rig tests. A cooling system evolved during the program which featured air impingement cooling for the vane platforms rather than film cooling. The impingement cooling system, in combination with the thermal barrier coatings, reduced platform cooling air requirements by 44% relative to the current film cooling system. Improved durability and reduced cooling air requirements were demonstrated in rig and engine endurance tests. Two engine tests were conducted, one of 1000 cycles and the other of 1500 cycles. All three coatings applied to vanes fabricated with the final cooling system configuration completed the final 1500 cycle engine endurance test. Results of this test clearly demonstrated the durability of the 6% YSZ coating which was in very good condition after the test. The 21% MSZ and 20% YSZ coatings had numerous occurrences of significant spalling in the test.

  13. Biotic Communities. [Project ECOLogy ELE Pak, Amoe-Thorson Pak].

    ERIC Educational Resources Information Center

    Amoe, Ruth; Thorson, Michael

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit provides a number of activities to introduce students to ways of studying biotic communities, help them become good observers, and provide them with opportunities to use their skills. The materials include suggested activities, and…

  14. Your Nose Knows. [Project ECOLogy ELE Pak, Meaney Pak].

    ERIC Educational Resources Information Center

    Meaney, Marie

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed for kindergarten pupils, but could be used effectively with primary pupils. The six lessons use the sense of smell to investigate various aspects of the earth, seasons, animals, and commercial use of fragrances. Each lesson…

  15. Exponential Explosions! Today.... Tomorrow.... ? [Project ECOLogy ELE Pak, Jensen Pak].

    ERIC Educational Resources Information Center

    Jensen, Melanie

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for junior high school mathematics classes and emphasizes applications of exponents to problems of population growth and pollution. The nine lessons are designed for about eleven school days. Each lesson includes the concept…

  16. And Then - Recycling. [Project ECOLogy ELE Pak, Lewis Pak].

    ERIC Educational Resources Information Center

    Lewis, Dave

    This is one of a series of units for environmental education developed by the Highline Public Schools. There are seven concepts in this unit on recycling which is designed for grade five and six students. Each concept has one lesson that is comprised of several activities. Several suggested extra activities have been added to further the students'…

  17. From Rocks to Pots. [Project ECOLogy ELE Pak, Grim Pak].

    ERIC Educational Resources Information Center

    Grim, Dale

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for use by art classes at the secondary school level; it illustrates the availability of natural clay and provides the student with experiences such as digging the clay, locating desirable clays, preparing it for production,…

  18. Natural or Organic Foods? [Project ECOLogy ELE Pak, Schmidt Pak].

    ERIC Educational Resources Information Center

    Schmidt, Linda

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for secondary students in home economics classes. The content of the units focuses on natural and organic foods, characteristics of the foods, and uses of the foods. The seven lessons in this unit are designed to last over a…

  19. Archaeology/Ecology. [Project ECOLogy ELE Pak, Muccilli Pak].

    ERIC Educational Resources Information Center

    Muccilli, Kathie

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit was written for seventh-grade students in anthropology. The six lessons and suggested activities will take from 15 to 30 days to complete. Each lesson includes the concept of the lesson, materials needed, notes to the teacher,…

  20. Energy Futures... [Project ECOLogy ELE Pak, Parr Pak].

    ERIC Educational Resources Information Center

    Parr, Donald

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit on energy is designed for junior high school science students. The 11 concepts of the unit have been developed into 11 lessons that should take from two to three weeks to complete. Each lesson includes the concept of the lesson,…

  1. Sorption J-T refrigeration utilizing manganese nitride chemisorption

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Lund, Alan

    1990-01-01

    The equilibrium pressures and compositions have been measured for a system of finely powdered manganese nitride and nitrogen gas at 650, 700, 800, and 850 C for various nitrogen loadings. Pressures ranged from less than 0.02 MPa at 650 C to 6.38 MPa at 850 C. Analysis of the test results has shown that under certain conditions Mn(x)N(y) could potentially be used in a triple regenerative sorption compressor refrigeration system, but the potential power savings are small compared to the increased complexity and reliability problems associated with very high temperature (above 950 C) pressurized systems.

  2. Recent results on radio frequency experiments in JT-60U

    SciTech Connect

    Kimura, H.; Naito, O.; Saigusa, M.; lde, S.; Nemoto, M.; Ikeda, Y.; Moriyama, S.; Kondoh, T.; Fujii, T.; Seki, M.; Kusama, Y.; Afanassiev, V.I.; Tuccillo, A.A.; Podda, S.; Fang, Y.; Ushigusa, K.; Kamada, Y.; Ishida, S.; Neyatani, Y.; Hamamatsu, K.; Tobita, K.

    1996-02-01

    Sawtooth relaxation is suppressed during ELM-free period by second harmonic minority ICRF heating in 4MA H-mode experiments with high power NBI heating. TAE modes in high plasma current regime (up to 4MA) are investigated with ICRF heating, where high-n TAE modes (n more than 10) appear. TAE amplitude increases with increasing toroidal mode number. The ion energy spectrum is measured up to 1 MeV during higher harmonic beam ion acceleration (from 2nd to 5th harmonics). The tail ion temperature increases with increasing harmonic number up to 4th harmonics. The lower hybrid (LH) wave deposition profile (therefore the driven current profile) can be controlled by changing launched wave spectra (phase velocity, spectral width, compound spectra) or changing geometry (launching position, safety factor). It is also demonstrated to drive noninductive current in the opposite direction to the ohmic current by LH waves for enhancement of the current profile controllability. Antenna coupling with a large separatrix-antenna gap is demonstrated for both fast waves and LH waves and some related issues are discussed. {copyright} {ital 1996 American Institute of Physics.}

  3. Eco-Kids: Experiment with Air on Spaceship Earth. [Project ECOLogy ELE Pak, Bell Pak].

    ERIC Educational Resources Information Center

    Bell, Loretta

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit, designed for intermediate grades in the elementary schools, is concerned with the study of air, air pollution, effects of air pollution, and ways of improving the quality of the air. Six lessons are included in the unit; most of the…

  4. The Sky Is Falling: A Study Of Particulates... . [Project ECOLogy ELE Pak, Thompson Pak].

    ERIC Educational Resources Information Center

    Thompson, Dennis W.

    This is one of a series of units for environmental education developed by the Highline Public Schools. Designed for secondary school science classes, the unit is concerned with particulate matter of air pollution. Five lessons are included. The lessons include construction of equipment and collecting data. (RH)

  5. Exploration with Garbage. [Project ECOLogy ELE Pak, Lund and Wolff Pak].

    ERIC Educational Resources Information Center

    Lund, Cherie; Wolff, Chanelle

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is concerned with the topic of garbage. The eleven lessons explore what garbage is, problems of littering, ways to reduce garbage, and ways to use garbage. The materials were designed to be used with kindergarten pupils, but could be…

  6. Food: The Challenge to Manage. [Project ECOLogy ELE Pak, Roush Pak].

    ERIC Educational Resources Information Center

    Roush, Judy

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for students at the senior high level who have a basic knowledge of nutrition, some experience in menu planning, and who are ready to put this knowledge of nutrition to work in selecting foods to attain maximum nutrition with…

  7. Eco-Kids Fly Off to the Forests. [Project ECOLogy ELE Pak, Bell Pak].

    ERIC Educational Resources Information Center

    Bell, Loretta

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit was designed for use with fourth-grade students; it focuses on three forest biomes. Each of the biomes has characteristics of its own. The unit includes eight lessons, as well as additional activities. The unit, which incorporates…

  8. Ever Stop to Think Man's Survival Is Dependent on His Use of Food Resources? [Project ECOLogy ELE Pak, Nelson Pak].

    ERIC Educational Resources Information Center

    Nelson, Judy

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed for senior high school students who have a basic knowledge of nutrition and some experience in menu planning. The five lessons provide experiences in selecting, preparing, and storing foods to attain maximum nutrition with a…

  9. Accumulations of heavy metals in roadside soils close to zhaling, eling and nam co lakes in the tibetan plateau.

    PubMed

    Yan, Xuedong; Zhang, Fan; Gao, Dan; Zeng, Chen; Xiang, Wang; Zhang, Man

    2013-06-07

    Concentrations of four typical heavy metals (Cu; Zn; Cd and Pb) in roadside soils close to three lakes in the Tibetan Plateau were investigated in this study. The hierarchical tree-based regression method was applied to classify concentrations of the heavy metals and analyze their potential influencing factors. It was found that the Tibetan Plateau meadow soils with higher content of sand lead to higher concentrations of Cu; Zn and Pb. The concentrations of Cd and Pb increase with road traffic volume; and for the road segments with higher traffic volume; the Cd and Pb concentrations significantly decrease with the roadside distance. Additionally; the concentrations of Zn and Pb increase as the altitude of sampling site increases. Furthermore; the Hakanson potential ecological risk index method was used to assess the contamination degree of the heavy metals for the study regions. The results show that accumulations of Cu; Zn and Pb in roadside soils remain an unpolluted level at all sites. However; the Cd indices in the regions with higher traffic volume have reached a strong potential ecological risk level; and some spots with peak concentrations have even been severely polluted due to traffic activities.

  10. Accumulations of Heavy Metals in Roadside Soils Close to Zhaling, Eling and Nam Co Lakes in the Tibetan Plateau

    PubMed Central

    Yan, Xuedong; Zhang, Fan; Gao, Dan; Zeng, Chen; Xiang, Wang; Zhang, Man

    2013-01-01

    Concentrations of four typical heavy metals (Cu; Zn; Cd and Pb) in roadside soils close to three lakes in the Tibetan Plateau were investigated in this study. The hierarchical tree-based regression method was applied to classify concentrations of the heavy metals and analyze their potential influencing factors. It was found that the Tibetan Plateau meadow soils with higher content of sand lead to higher concentrations of Cu; Zn and Pb. The concentrations of Cd and Pb increase with road traffic volume; and for the road segments with higher traffic volume; the Cd and Pb concentrations significantly decrease with the roadside distance. Additionally; the concentrations of Zn and Pb increase as the altitude of sampling site increases. Furthermore; the Hakanson potential ecological risk index method was used to assess the contamination degree of the heavy metals for the study regions. The results show that accumulations of Cu; Zn and Pb in roadside soils remain an unpolluted level at all sites. However; the Cd indices in the regions with higher traffic volume have reached a strong potential ecological risk level; and some spots with peak concentrations have even been severely polluted due to traffic activities. PMID:23749055

  11. Development of a low noise 10 K J-T refrigeration system

    NASA Astrophysics Data System (ADS)

    Little, William A.

    1987-06-01

    This report summarizes work done on the development of a low noise Joule-Thompson, microminiature refrigeration system designed for 10 K operation. Topics discussed include: calculation of phase diagram of mixtures of certain hydrocarbon gases with nitrogen using the Benedict-Webb-Rubin equation of state, the set up of a magnetron-enhanced sputtering system to allow us to sputter a layer of adhesive on the glass substrates with a much better defined thickness than can be laid down using the older screen printing method, Redesign of H2 Refrigerator Test Stage, Redesign of Mixed Gas Heat Exchanger, Refrigerator Fabrication, Gas Cleaner.

  12. DC-9 flight demonstration program with refanned JT8D engines. Volume 2: Design and construction

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The nacelle configuration selected for the DC-9 had a 1595.6 mm Refan length inlet and an 1811.8 mm exhaust duct. The inlet had 1234.4 mm of acoustic treatment and the tailpipe had 1305.5 mm of equivalent length acoustic treatment. The pylon was reduced in width from 425.5 mm to 204.5 mm. Fuselage frames and titanium skin panels in the area of the pylon were reinforced or replaced to support the higher loads and engine thrust. Experimental type tooling, fabrication and assembly were used on all hardware. The design is considered certifiable and representative of the hardware that would be built as retrofit kits.

  13. Short-term performance deterioration in JT9D-7A(SP) engine 695743

    NASA Technical Reports Server (NTRS)

    Bouchard, R. J.; Beyerly, W. R.; Sallee, G. P.

    1978-01-01

    The level of performance deterioration that occurred during early service was studied and also the contribution of each engine module to the overall level of engine performance deterioration. To assist in the distribution of the performance losses to the module level, testing with expanded experimental instrumentation was accomplished to permit direct measurement of module performance. An analytical teardown of the engine was accomplished to permit assignment of module performance losses to individual mechanical damage mechanisms including blade and seal wear, roughness, and thermal distortion of turbine parts. The results of the testing show that the engine deteriorated 1.5 percent in thrust specific fuel consumption from its performance when new. Initial testing, which included water washing, showed that 0.2 percent in performance deterioration was due to surface contamination (dirt) and 0.1 percent was due to drift of the engine vane control system, leaving 1.2 percent in basic TSFC deterioration. This 1.2 percent TSFC loss was distributed among the engine modules with 0.6 percent caused by clearance changes, 0.4 percent loss due to thermal distortion, and 0.2 percent loss due to increased roughness of the fan and low-pressure compressor airfoils.

  14. Effect of steady flight loads on JT9D-7 performance deterioration

    NASA Technical Reports Server (NTRS)

    Jay, A.; Todd, E. S.

    1978-01-01

    Short term engine deterioration occurs in less than 250 flights on a new engine and in the first flights following engine repair; while long term deterioration involves primarily hot section distress and compression system losses which occur at a somewhat slower rate. The causes for short-term deterioration are associated with clearance changes which occur in the flight environment. Analytical techniques utilized to examine the effects of flight loads and engine operating conditions on performance deterioration are presented. The role of gyroscopic, gravitational, and aerodynamic loads are discussed along with the effect of variations in engine build clearances. These analytical results are compared to engine test data along with the correlation between analytically predicted and measured clearances and rub patterns. Conclusions are drawn and important issues are discussed.

  15. Performance deterioration based on simulated aerodynamic loads test, JT9D jet engine diagnostics program

    NASA Technical Reports Server (NTRS)

    Stromberg, W. J.

    1981-01-01

    An engine was specially prepared with extensive instrumentation to monitor performance, case temperatures, and clearance changes. A special loading device was used to apply known loads on the engine by the use of cables placed around the flight inlet. These loads simulated the estimated aerodynamic pressure distributions that occur on the inlet in various segments of a typical airplane flight. Test results indicate that the engine lost 1.3 percent in take-off thrust specific fuel consumption (TSFC) during the course of the test effort. Permanent clearance changes due to the loads accounted for 1.1 percent; increase in low pressure compressor airfoil roughness and thermal distortion in the high pressure turbine accounted for 0.2 percent. Pretest predicted performance loss due to clearance changes was 0.9 percent in TSFC. Therefore, the agreement between measurement and prediction is considered to be excellent.

  16. Development of jt Coolers Operating at Cryogenic Temperatures with Nonflammable Mixed Refrigerants

    NASA Astrophysics Data System (ADS)

    Khatri, A.; Boiarski, M.

    2008-03-01

    Throttle cycle coolers, operating with mixed refrigerants have been already used at refrigeration temperatures down to 70 K. An industrial single-stage, oil lubricated compressor can be used to provide both, a relatively low cost and long operational time. Application of nonflammable mixed refrigerants is important for safety, transportation, service and maintenance. However, it is more difficult to provide a required refrigeration performance and long-term reliability due to properties of nonflammable components. The paper presents experimental and modeling data for single-stage coolers operating in a temperature range of 80 to 150 K. The nonflammable components were selected to develop mixed refrigerants for the desired temperature ranges. A gas refrigerant supply technology is used for a single-stage cooler design. The minimal achievable temperature is restricted by the freezing point of the mixture. Selected gas refrigerant technology restricts the maximal refrigeration capacity. However, it allows a compromise between stable, long-term reliable operation and simplicity of equipment design. Stability of operation of small-scale, highly reliable coolers has been proven by the data accumulated over more than one year of testing.

  17. DEVELOPMENT OF A LOW HEAT LEAK CFRP STAND FOR MIRI COOLER JT HEAT EXCHANGER STAGE

    SciTech Connect

    Makowski, K. P.; Hayashil, B.; Larson, M. E.; Loc, A. S.; Zhang, B. X.; Leland, R. S.

    2010-04-09

    A low heat leak stand is being developed for the Heat exchanger Stage Assembly (HSA) of the cryocooler subsystem for the Mid Infra-Red Instrument (MIRI) of the James Webb Space Telescope (JWST). The HSA stand is a hexapod structure supporting the 18 K HSA in a nominal 40 K background environment. Carbon fiber reinforced plastic (CFRP) has been selected for this application to meet the stringent design requirements of a low parasitic heat leak (less than 3.8 mW including both conductive and radiative heat loads for the thermal environment defined above) and a resonance frequency above 120 Hz. A directional lay-up of T300/polycyanate has been chosen for the construction of the hexapod struts. End fittings made of Invar 36 are bonded to the struts to provide structural interfaces. The development effort includes fabricating and testing (including cryogenic thermal cycling) six types of coupons for material characterization, determination of structural degradation due to thermal cycling, and selection of the joint bonding epoxy. Consequently, strut samples are used for final material characterization, performance assessment, and bond joint design evaluation. This paper describes the development process and addresses the challenges in meeting the design requirements. Results of finite element analysis (FEA) for the composite structure and experimental data collected through structural and thermal testing are also presented.

  18. Development of a Low Heat Leak CFRP Stand for Miri Cooler jt Heat Exchanger Stage

    NASA Astrophysics Data System (ADS)

    Makowski, K. P.; Larson, M. E.; Loc, A. S.; Zhang, B. X.; Leland, R. S.; Hayashi1, B.

    2010-04-01

    A low heat leak stand is being developed for the Heat exchanger Stage Assembly (HSA) of the cryocooler subsystem for the Mid Infra-Red Instrument (MIRI) of the James Webb Space Telescope (JWST). The HSA stand is a hexapod structure supporting the 18 K HSA in a nominal 40 K background environment. Carbon fiber reinforced plastic (CFRP) has been selected for this application to meet the stringent design requirements of a low parasitic heat leak (less than 3.8 mW including both conductive and radiative heat loads for the thermal environment defined above) and a resonance frequency above 120 Hz. A directional lay-up of T300/polycyanate has been chosen for the construction of the hexapod struts. End fittings made of Invar 36 are bonded to the struts to provide structural interfaces. The development effort includes fabricating and testing (including cryogenic thermal cycling) six types of coupons for material characterization, determination of structural degradation due to thermal cycling, and selection of the joint bonding epoxy. Consequently, strut samples are used for final material characterization, performance assessment, and bond joint design evaluation. This paper describes the development process and addresses the challenges in meeting the design requirements. Results of finite element analysis (FEA) for the composite structure and experimental data collected through structural and thermal testing are also presented.

  19. Performance characterization of a 6-K multiple JT helium adsorption cryocooler

    NASA Technical Reports Server (NTRS)

    Elliot, S.; Johnson, D. L.; Lindersmith, C. A.; Sirbi, A.

    2002-01-01

    We present the work done at the Jet Propulsion Laboratory for a Helium Adsorption Cooler to produce continuous cooling power at a temperature around 6 K. The goal of this development is to be able to propose for future space mission a long lifetime, vibration free cooler, which can cover the temperature range 18 K to 5 K.

  20. Program on ground test of modified quiet, clean, JT3D and JT8D turbofan engines in their respective nacelles. [modification of Boeing 707, 727, and 737 aircraft for aircraft noise reduction

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A program to reduce the community noise levels of commercial jet aircraft is summarized. The program objective is the development of three acoustically treated nacelle configurations for the 707, 727, and 737 series aircraft to provide maximum noise reduction with minimum performance loss, modification requirements, and economic impact. The preliminary design, model testing, data analyses, and economic studies of proposed nacelle configurations are discussed.

  1. Low speed wind tunnel flow field results for JT8D refan engines on the Boeing 727-200

    NASA Technical Reports Server (NTRS)

    Easterbrook, W. G.; Roberts, W. H.

    1974-01-01

    Low speed flow angularity results are presented showing flow direction at the nacelle locations on the Boeing 727-200. Flow angle probes (yawheads) were used for measurements at side and center inlet positions on the aft fuselage. A range of flap settings were tested with flap angles of 0 deg, 15 deg, and 40 deg selected for investigation.

  2. 76 FR 16526 - Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A, -217C, and -219 Series Turbofan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-24

    ...-209, -217, -217A, -217C, and -219 Series Turbofan Engines AGENCY: Federal Aviation Administration (FAA...-13948 (70 FR 3867, January 27, 2005). That AD applies to the specified products. The NPRM published in the Federal Register on July 1, 2010 (75 FR 38052). That NPRM proposed the same torque...

  3. Evaluation of two inflow control devices for flight simulation of fan noise using a JT15D engine

    NASA Technical Reports Server (NTRS)

    Jones, W. L.; Mcardle, J. G.; Homyak, L.

    1979-01-01

    The program was developed to accurately simulate flight fan noise on ground static test stands. The results generally indicated that both the induct and external ICD's were effective in reducing the inflow turbulence and the fan blade passing frequency tone generated by the turbulence. The external ICD was essentially transparent to the propagating fan tone but the induct ICD caused attenuation under most conditions.

  4. 76 FR 8620 - Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A, -217C, and -219 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ...-14242 (70 FR 71610, November 29, 2005). That AD applies to the specified products. The NPRM published in the Federal Register on August 18, 2010 (75 FR 50945). That NPRM proposed to modify the TLS of the... Executive Order 12866; (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44...

  5. 75 FR 50945 - Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A, -217C, and -219 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78...-02, Amendment 39-14242 (70 FR 52004, September 1, 2005), to require revisions to the TLS of the... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Would not have a...

  6. 75 FR 12968 - Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217C, and -219 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... (62 FR 4902). ADDRESSES: You can get the service information identified in this AD from Pratt... proposed AD in the Federal Register on December 21, 2009 (74 FR 67831). That action proposed to require...'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) Will not have...

  7. 76 FR 41144 - Airworthiness Directives; Pratt & Whitney Corp. (PW) JT9D-7R4H1 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ... proposed AD would require removing certain high-pressure compressor (HPC) shafts before their certified... operating metal ] temperatures impose a greater low-cycle fatigue life debit for each operating cycle... that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce...

  8. 76 FR 77107 - Airworthiness Directives; Pratt & Whitney Corp. (PW) JT9D-7R4H1 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ... reports of cracks in five high-pressure compressor (HPC) shafts. This AD requires removing certain HPC... FR 41144). That NPRM proposed to require: For HPC shafts that have more than 4,500 cycles-since-new..., and determined that air safety and the public interest require adopting the AD with the...

  9. 75 FR 38052 - Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A, -217C, and -219 Series Turbofan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ... April 11, 2000 (65 FR 19477-78). Examining the AD Docket You may examine the AD docket on the Internet... 39 by superseding AD 2005-02- 03, Amendment 39-13948 (70 FR 3867, January 27, 2005). That AD requires... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Would not have a...

  10. 75 FR 27972 - Airworthiness Directives; Pratt & Whitney JT8D-9, -9A, -11, -15, -17, and -17R Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-19

    .... This proposed AD would require overhauling fan blade leading edges at the first shop visit after 4,000 cycles-in-service (CIS) since the last total fan blade overhaul was performed. This proposed AD results from reports of failed fan blades. We are proposing this AD to prevent high-cycle fatigue cracking...

  11. Wind tunnel test of model target thrust reversers for the Pratt and Whitney aircraft JT8D-100 series engines installed on a 727-200 airplane

    NASA Technical Reports Server (NTRS)

    Hambly, D.

    1974-01-01

    The results of a low speed wind tunnel test of 0.046 scale model target thrust reversers installed on a 727-200 model airplane are presented. The full airplane model was mounted on a force balance, except for the nacelles and thrust reversers, which were independently mounted and isolated from it. The installation had the capability of simulating the inlet airflows and of supplying the correct proportions of primary and secondary air to the nozzles. The objectives of the test were to assess the compatibility of the thrust reversers target door design with the engine and airplane. The following measurements were made: hot gas ingestion at the nacelle inlets; model lift, drag, and pitching moment; hot gas impingement on the airplane structure; and qualitative assessment of the rudder effectiveness. The major parameters controlling hot gas ingestion were found to be thrust reverser orientation, engine power setting, and the lip height of the bottom thrust reverser doors on the side nacelles. The thrust reversers tended to increase the model lift, decrease the drag, and decrease the pitching moment.

  12. Experimental validation of non-uniformity effect of the radial electric field on the edge transport barrier formation in JT-60U H-mode plasmas.

    PubMed

    Kamiya, K; Itoh, K; Itoh, S-I

    2016-01-01

    The turbulent structure formation, where strongly-inhomogeneous turbulence and global electromagnetic fields are self-organized, is a fundamental mechanism that governs the evolution of high-temperature plasmas in the universe and laboratory (e.g., the generation of edge transport barrier (ETB) of the H-mode in the toroidal plasmas). The roles of inhomogeneities of radial electric field (Er) are known inevitable. In this mechanism, whether the first derivative of Er (shear) or the second derivative of Er (curvature) works most is decisive in determining the class of nontrivial solutions (which describe the barrier structure). Here we report the experimental identification of the essential role of the Er-curvature on the ETB formation, for the first time, based on the high-spatiotemporal resolution spectroscopic measurement. We found the decisive importance of Er-curvature on ETB formation during ELM-free phase, but there is only a low correlation with the Er-shear value at the peak of normalized ion temperature gradient. Furthermore, in the ELMing phase, the effect of curvature is also quantified in terms of the relationship between pedestal width and thickness of the layer of inhomogeneous Er. This is the fundamental basis to understand the structure of transport barriers in fusion plasmas. PMID:27480931

  13. 76 FR 5066 - Airworthiness Directives; Pratt & Whitney JT8D-7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ...-14398 (70 FR 73361, December 12, 2005). That AD applies to the specified products. The NPRM published in the Federal Register on August 18, 2010 (75 FR 50942). That NPRM proposed to modify the TLS of the... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will...

  14. 75 FR 50942 - Airworthiness Directives; Pratt & Whitney JT8D-7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ..., 2000 (65 FR 19477-78). Examining the AD Docket You may examine the AD docket on the Internet at http... AD 2005-25-05, Amendment 39- 14398 (70 FR 73361, December 12, 2005), to require revisions to the TLS.... Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034,...

  15. Experimental validation of non-uniformity effect of the radial electric field on the edge transport barrier formation in JT-60U H-mode plasmas

    NASA Astrophysics Data System (ADS)

    Kamiya, K.; Itoh, K.; Itoh, S.-I.

    2016-08-01

    The turbulent structure formation, where strongly-inhomogeneous turbulence and global electromagnetic fields are self-organized, is a fundamental mechanism that governs the evolution of high-temperature plasmas in the universe and laboratory (e.g., the generation of edge transport barrier (ETB) of the H-mode in the toroidal plasmas). The roles of inhomogeneities of radial electric field (Er) are known inevitable. In this mechanism, whether the first derivative of Er (shear) or the second derivative of Er (curvature) works most is decisive in determining the class of nontrivial solutions (which describe the barrier structure). Here we report the experimental identification of the essential role of the Er-curvature on the ETB formation, for the first time, based on the high-spatiotemporal resolution spectroscopic measurement. We found the decisive importance of Er-curvature on ETB formation during ELM-free phase, but there is only a low correlation with the Er-shear value at the peak of normalized ion temperature gradient. Furthermore, in the ELMing phase, the effect of curvature is also quantified in terms of the relationship between pedestal width and thickness of the layer of inhomogeneous Er. This is the fundamental basis to understand the structure of transport barriers in fusion plasmas.

  16. 75 FR 62319 - Airworthiness Directives; Pratt & Whitney JT8D-9, -9A, -11, -15, -17, and -17R Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-08

    ..., Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park... Federal Register on May 19, 2010 (75 FR 27972). That action proposed to require overhauling fan blade... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3)...

  17. Experimental validation of non-uniformity effect of the radial electric field on the edge transport barrier formation in JT-60U H-mode plasmas

    PubMed Central

    Kamiya, K.; Itoh, K.; Itoh, S.-I.

    2016-01-01

    The turbulent structure formation, where strongly-inhomogeneous turbulence and global electromagnetic fields are self-organized, is a fundamental mechanism that governs the evolution of high-temperature plasmas in the universe and laboratory (e.g., the generation of edge transport barrier (ETB) of the H-mode in the toroidal plasmas). The roles of inhomogeneities of radial electric field (Er) are known inevitable. In this mechanism, whether the first derivative of Er (shear) or the second derivative of Er (curvature) works most is decisive in determining the class of nontrivial solutions (which describe the barrier structure). Here we report the experimental identification of the essential role of the Er-curvature on the ETB formation, for the first time, based on the high-spatiotemporal resolution spectroscopic measurement. We found the decisive importance of Er-curvature on ETB formation during ELM-free phase, but there is only a low correlation with the Er-shear value at the peak of normalized ion temperature gradient. Furthermore, in the ELMing phase, the effect of curvature is also quantified in terms of the relationship between pedestal width and thickness of the layer of inhomogeneous Er. This is the fundamental basis to understand the structure of transport barriers in fusion plasmas. PMID:27480931

  18. Experimental validation of non-uniformity effect of the radial electric field on the edge transport barrier formation in JT-60U H-mode plasmas.

    PubMed

    Kamiya, K; Itoh, K; Itoh, S-I

    2016-08-02

    The turbulent structure formation, where strongly-inhomogeneous turbulence and global electromagnetic fields are self-organized, is a fundamental mechanism that governs the evolution of high-temperature plasmas in the universe and laboratory (e.g., the generation of edge transport barrier (ETB) of the H-mode in the toroidal plasmas). The roles of inhomogeneities of radial electric field (Er) are known inevitable. In this mechanism, whether the first derivative of Er (shear) or the second derivative of Er (curvature) works most is decisive in determining the class of nontrivial solutions (which describe the barrier structure). Here we report the experimental identification of the essential role of the Er-curvature on the ETB formation, for the first time, based on the high-spatiotemporal resolution spectroscopic measurement. We found the decisive importance of Er-curvature on ETB formation during ELM-free phase, but there is only a low correlation with the Er-shear value at the peak of normalized ion temperature gradient. Furthermore, in the ELMing phase, the effect of curvature is also quantified in terms of the relationship between pedestal width and thickness of the layer of inhomogeneous Er. This is the fundamental basis to understand the structure of transport barriers in fusion plasmas.

  19. Mitochondrial DNA (mtDNA) variants in the European haplogroups HV, JT, and U do not have a major role in schizophrenia.

    PubMed

    Torrell, Helena; Salas, Antonio; Abasolo, Nerea; Morén, Constanza; Garrabou, Glòria; Valero, Joaquín; Alonso, Yolanda; Vilella, Elisabet; Costas, Javier; Martorell, Lourdes

    2014-10-01

    It has been reported that certain genetic factors involved in schizophrenia could be located in the mitochondrial DNA (mtDNA). Therefore, we hypothesized that mtDNA mutations and/or variants would be present in schizophrenia patients and may be related to schizophrenia characteristics and mitochondrial function. This study was performed in three steps: (1) identification of pathogenic mutations and variants in 14 schizophrenia patients with an apparent maternal inheritance of the disease by sequencing the entire mtDNA; (2) case-control association study of 23 variants identified in step 1 (16 missense, 3 rRNA, and 4 tRNA variants) in 495 patients and 615 controls, and (3) analyses of the associated variants according to the clinical, psychopathological, and neuropsychological characteristics and according to the oxidative and enzymatic activities of the mitochondrial respiratory chain. We did not identify pathogenic mtDNA mutations in the 14 sequenced patients. Two known variants were nominally associated with schizophrenia and were further studied. The MT-RNR2 1811A > G variant likely does not play a major role in schizophrenia, as it was not associated with clinical, psychopathological, or neuropsychological variables, and the MT-ATP6 9110T > C p.Ile195Thr variant did not result in differences in the oxidative and enzymatic functions of the mitochondrial respiratory chain. The patients with apparent maternal inheritance of schizophrenia did not exhibit any mutations in their mtDNA. The variants nominally associated with schizophrenia in the present study were not related either to phenotypic characteristics or to mitochondrial function. We did not find evidence pointing to a role for mtDNA sequence variation in schizophrenia.

  20. Study of turbofan engines designed for low energy consumption

    NASA Technical Reports Server (NTRS)

    Gray, D. E.

    1976-01-01

    The near-term technology improvements which can reduce the fuel consumed in the JT9D, JT8D, and JT3D turbofans in commercial fleet operation through the 1980's are identified. Projected technology advances are identified and evaluated for new turbofans to be developed after 1985. Programs are recommended for developing the necessary technology.

  1. Analysis of a tobacco vector and its actions in china: the activities of japan tobacco

    PubMed Central

    2010-01-01

    Japan Tobacco (JT) is the third largest tobacco company in the world, and China, the world's largest tobacco consumer, is one of the most important targets for JT. To provide information for tobacco control, we reviewed and analyzed JT and its tactics and strategies in the Chinese market mainly by systematic examination of documents which are made available in the University of California, San Francisco Legacy Tobacco Documents Library. As a result, JT has had a special interest to expand sales of its cigarettes in the Chinese market. PMID:20979655

  2. EEsoF MICAD and ACADEMY macro files for coplanar waveguide and finite ground plan coplanar waveguide

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.

    1995-01-01

    A collection of macro files is presented which when appended to either the EEsoF MICAD.ELE or EEsoF ACADEMY.ELE file permits the layout of coplanar waveguide and finite ground plane coplanar waveguide circuits.

  3. Percolation features of cooperative Jahn-Teller systems: Ising EFT framework

    NASA Astrophysics Data System (ADS)

    Moujaes, Elie A.; Abou Ghantous, Michel

    2014-08-01

    Elastic exchange between two nearest Jahn-Teller (JT) centers in two or three dimensional dense crystals, can give an ordered macroscopic distortion known as cooperative JT effect (CJTE). A very diluted JT crystal does not show this effect. In the dynamic JT effect (DJTE), tunneling between different equivalent distorted wells has a pronounced influence on the CJTE. We investigate this phenomenon using a progressive increase in the concentration of these centers in the JT crystals, based on a bond percolation vector spin analogy technique within the framework of effective field theory (EFT). Mean field theory (MFT) was extensively used in previous studies of CJTE; however it neither includes correlation between JT centers in the lattice due to the complexity of the distortion field in the crystal nor the effect of tunneling between wells. We resort to an alternative procedure, by describing a JT center as a pseudo-spin vector , induced to represent the degenerate JT-distorted states, where two nearest JT centers interact via an elastic exchange described by an Ising type spin interaction. The DJTE is considered to be similar to an elastic transverse field term in the Hamiltonian portraying the effect of tunneling between equivalent wells in the adiabatic potential energy surface (APES). We will be particularly discussing S = 1, S = 3/2 and S = 5/2 spin cases, where 2 S + 1 wells in the APES are present and what JT systems they actually represent, with a percolative mechanism applied to the interactions between different JT centers. The different lattices are distinguished by their coordination numbers. Strong tunneling effects can suppress the CJTE and lead to a new state of criticality. Generalizations to higher spin systems will be obtained using a scaling technique. For the relevant distortions, we determine single site correlations, the macroscopic average distortion describing a structural phase transition and the elastic isothermal susceptibility as a

  4. Managing Innovation in English Language Education

    ERIC Educational Resources Information Center

    Waters, Alan

    2009-01-01

    Innovation in English language education (ELE) has become a major "growth area" in recent years. At the same time, an ELE innovation management literature has also developed, based on insights from innovation theory and their application, both from outside and within ELE, and concerned with attempting to critically evaluate and inform ELE…

  5. Engine component improvement program: Performance improvement. [fuel consumption

    NASA Technical Reports Server (NTRS)

    Mcaulay, J. E.

    1979-01-01

    Fuel consumption of commercial aircraft is considered. Fuel saving and retention components for new production and retrofit of JT9D, JT8D, and CF6 engines are reviewed. The manner in which the performance improvement concepts were selected for development and a summary of the current status of each of the 16 selected concepts are discussed.

  6. Construction of new cloning, lacZ reporter and scarless-markerless suicide vectors for genetic studies in Aggregatibacter actinomycetemcomitans.

    PubMed

    Juárez-Rodríguez, María Dolores; Torres-Escobar, Ascención; Demuth, Donald R

    2013-05-01

    To elucidate the putative function of a gene, effective tools are required for genetic characterization that facilitate its inactivation, deletion or modification on the bacterial chromosome. In the present study, the nucleotide sequence of the Escherichia coli/Aggregatibacter actinomycetemcomitans shuttle vector pYGK was determined, allowing us to redesign and construct a new shuttle cloning vector, pJT4, and promoterless lacZ transcriptional/translational fusion plasmids, pJT3 and pJT5. Plasmids pJT4 and pJT5 contain the origin of replication necessary to maintain shuttle vector replication. In addition, a new suicide vector, pJT1, was constructed for the generation of scarless and markerless deletion mutations of genes in the oral pathogen A. actinomycetemcomitans. Plasmid pJT1 is a pUC-based suicide vector that is counter-selectable for sucrose sensitivity. This vector does not leave antibiotic markers or scars on the chromosome after gene deletion and thus provides the option to combine several mutations in the same genetic background. The effectiveness of pJT1 was demonstrated by the construction of A. actinomycetemcomitans isogenic qseB single deletion (ΔqseB) mutant and lsrRK double deletion mutants (ΔlsrRK). These new vectors may offer alternatives for genetic studies in A. actinomycetemcomitans and other members of the HACEK (Haemophilus spp., A. actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae) group of Gram-negative bacteria.

  7. Photoluminescence properties of Jahn-Teller transition-metal ions

    NASA Astrophysics Data System (ADS)

    Sanz-Ortiz, Marta N.; Rodríguez, Fernando

    2009-09-01

    This work investigates the influence of electron-phonon coupling associated with E ⊗e and T ⊗e Jahn-Teller (JT) effect in different transition-metal (TM) ions on de-excitation phenomena through nonradiative multiphonon relaxation, i.e., photoluminescence (PL) quenching. We developed a configurational curve model which is able to predict from the absorption spectrum whether a given JT-TM ion is PL or quenched. The prediction is made on the basis of an adapted Dexter-Klick-Russell parameter for JT systems, defined in terms of spectroscopic parameters through ΛJT=αΔeabs/Eabs, where Δeabs refers to the splitting of the parent octahedral Eg states by the JT distortion in E ⊗e (α =3/4) or T ⊗e (α =1/4), and Eabs is the energy of the first absorption band involving electronic transition between Eg and T2g. We show that PL in any JT-TM ion occurs whenever ΛJT<0.1 or is quenched if ΛJT>0.2. This result is noteworthy since it allows us to establish structural requirements for the JT-TM ion and the host crystal to be PL. Although PL properties of materials containing TM ions depend on a variety of structural factors such as the electronic configuration, the site symmetry, and the crystal field produced by neighboring atoms, the present model achieves this goal through a simple spectroscopic parameter: ΛJT. In this work we correlated the PL properties of different sixfold-coordinated JT systems such as Ti3+, Cu2+, Mn3+, Cr2+, Fe2+, Co3+, and Ni3+ in halides and oxides with ΛJT obtained from their respective absorption spectra. From this analysis we conclude that depending on the nature of the JT coupling and its strength, PL is either strongly favored or quenched in T ⊗e while it is mostly quenched in E ⊗e systems due to the larger JT distortion.

  8. Mixed refrigerant Joule-Thomson sorption cryocoolers

    NASA Astrophysics Data System (ADS)

    Tzabar, Nir; Grossman, Gershon

    2014-01-01

    Joule-Thomson (JT) sorption cryocooling is the most mature technology for cooling from a normal Room-Temperature (RT) down to temperatures below 100 K in the absence of moving parts. Therefore, high reliability and no vibrations are attainable, in comparison with other cryocoolers. Cooling to 80 - 100 K with JT cryocoolers is often implemented with pure nitrogen. Alternatively, mixed refrigerants have been suggested for reducing the operating pressures to enable closed cycle cryocooling. There is a variety of publications describing nitrogen sorption cryocoolers with different configurations of sorption compressors. In the present research we suggest a novel sorption JT cryocooler that operates with a mixed refrigerant. Merging of sorption cryocooling and a mixed refrigerant enables the use of a simple, single stage compressor for cooling to 80 - 100 K, lower operating temperatures of the sorption cycle, and thus - reduced power consumption. In previous studies we have analyzed sorption compressors for mixed gases and mixed refrigerants for JT cryocoolers, separately. In this paper the option of mixed refrigerant sorption JT cryocoolers is explored. The considerations for developing mixed refrigerants to be driven by sorption compressors and to be utilized with JT cryocoolers are provided. It appears that, unlike with pure nitrogen, mixed refrigerants can be suitable for JT cryocooling with a single stage sorption compressor.

  9. Clogging of Joule-Thomson Devices in Liquid Hydrogen-Lunar Lander Descent Stage Operating Regime

    NASA Astrophysics Data System (ADS)

    Jurns, J. M.

    2010-04-01

    Joule-Thomson (J-T) devices have been identified as critical components for future space exploration missions. The NASA Constellation Program lunar architecture considers LOX/LH2 propulsion for the lunar lander descent stage main engine an enabling technology, ensuring the cryogenic propellants are available at the correct conditions for engine operation. This cryogenic storage system may utilize a Thermodynamic Vent System (TVS) that includes J-T devices to maintain tank fluid pressure and temperature. Previous experimental investigations have indicated that J-T devices may become clogged when flowing LH2 while operating at a temperature range from 20.5 K to 24.4 K. It has been proposed that clogging is due to a trace amount of metastable, supercooled liquid neon in the regular LH2 supply. In time, flow blockage occurs from accretion of solid neon on the orifice. This clogging poses a realistic threat to spacecraft propulsion systems utilizing J-T devices in cryogenic pressure control systems. TVS failure due to J-T clogging would prevent removal of environmental heat from the propellant and potential loss of mission. This report describes J-T clogging tests performed with LH2. Tests were performed in the expected Lunar Lander operating regime, and several methods were evaluated to determine the optimum approach to mitigating the potential risk of J-T clogging.

  10. A four-way junction with triple-helical arms: design, characterization, and stability.

    PubMed

    Makube, N; Klump, H H

    2000-05-01

    The formation of the four-way junction containing four triple-helical arms has been demonstrated using chemical methods (polyacrylamide gel electrophoresis and chemical footprinting using OsO(4) as a probe) and physical methods (UV absorbance melting and DSC). The junction J(T1T3) was assembled from two 20-mer purine strands and two 44-mer pyrimidine strands. To determine the contribution of the different arms to the stability of the complete structure of J(T1T3), the junction was compared to two simplified substructures, J(T1) and J(T3), respectively. Common to these complexes is the underlying double-helical four-way junction Js. Addition of Na(+) had a profound effect on stabilizing and subsequently folding the junctions into the stacked X-structures. The following results support the structure present: (i) The native polyacrylamide electrophoresis exhibits only a single band(s) corresponding to one species present when all four single strands are mixed in equal amounts. (ii) OsO(4) modifications were investigated at pH 5.0 and in the presence of 10 mM Mg(2+) and 100 mM Na(+). There is no cleavage of thymine residues at the branch point and throughout the structure. (iii) The thermal unfolding of J(T1) and J(T3) illustrates that the triple-helical arms are more stable than the double-helical arms which are contained in these junctions and that J(T1T3) with four triple-helical arms is slightly more stable than J(T1) and J(T3). (iv) The calorimetric transition enthalpies determined for the arms of J(T1T3) are comparable to those associated with the unfolding of its corresponding arms in J(T1) and J(T3). The results also illustrate that the formation of the junctions is not restricted by the pH, [Na(+)], sequence composition of the arms, and/or the loop position.

  11. Genetics Home Reference: hereditary diffuse gastric cancer

    MedlinePlus

    ... JT, van Hillegersberg R, Dekker E, Oliveira C, Cats A, Hoogerbrugge N; Dutch Working Group on Hereditary ... JH, van Hillegersberg R, Ligtenberg M, Bleiker E, Cats A; Dutch Working Group on Hereditary Gastric Cancer. ...

  12. Discretionary Review by the Occupational Safety and Health Review Commission: Is It Necessary?

    ERIC Educational Resources Information Center

    Moran, Robert D.

    1974-01-01

    Deficiencies in the Occupational Safety and Health Review Commission (OSAHRC), a court system created to carry out adjudicatory functions under the Williams-Steiger Occupational Safety and Health Act of 1970, are exposed and alternative solutions offered. (JT)

  13. Freedom of Expression at Yale

    ERIC Educational Resources Information Center

    AAUP Bulletin, 1975

    1975-01-01

    A report of the Committee on Freedom of Expression at Yale appointed by the president to examine the condition of free expression, peaceful dissent, mutual respect and tolerance at Yale and to draft recommendations for maintenance of those principles. (JT)

  14. Flight effects of fan noise

    NASA Astrophysics Data System (ADS)

    Chestnutt, D.

    1982-09-01

    Simulation of inflight fan noise and flight effects was discussed. The status of the overall program on the flight effects of fan noise was reviewed, and flight to static noise comparisons with the JT15D engine were displayed.

  15. Teasing Hamsters in Electric Cages?

    ERIC Educational Resources Information Center

    Page, Colin Flood

    1975-01-01

    Reviews several studies that examine the climate of feeling surrounding training courses for college teachers and the general social atmosphere of the job into which the trainee is being initiated. (JT)

  16. Acid Reflux (Gastroesophageal Reflux Disease) in Adults (Beyond the Basics)

    MedlinePlus

    ... sphincter. The most common surgical treatment is the laparoscopic Nissen fundoplication. This procedure involves wrapping the upper ... Ovaska JT. Comparison of long-term outcome of laparoscopic and conventional nissen fundoplication: a prospective randomized study ...

  17. Flight effects of fan noise

    NASA Technical Reports Server (NTRS)

    Chestnutt, D. (Editor)

    1982-01-01

    Simulation of inflight fan noise and flight effects was discussed. The status of the overall program on the flight effects of fan noise was reviewed, and flight to static noise comparisons with the JT15D engine were displayed.

  18. Study on a Miniature Mixed-gases Joule-Thomson Cooler Driven by an Oil-lubricated Mini-compressor for 120 K Temperature Ranges

    NASA Astrophysics Data System (ADS)

    Gong, M. Q.; Wu, J. F.; Yan, B.; Zou, X.; Zhuang, X. R.; Hu, Q. G.

    In this paper, a miniature J-T cooler using multicomponent mixtures was developed and tested, in which an oil-lubricated mini-compressor was used. Experimental tests on the performance of the miniature J-T cooler were carried out with two kinds of recuperative heat exchangers. One is a shell-and-tube heat exchanger, and the other is a plate-fin type recuperative heat exchanger with whereas a micro-channel configuration fabricated by the wire-electrode cutting method. The former one gave a no-load minimum temperature of 140 K, while the later one showsbetter performance. No-load minimum temperature of 110 K and about 4 W cooling capacity at 118 K were achieved with the plate-fin micro J-T cooler. Such miniature J-T coolers driven by oil-lubricated mini-compressors show good prospects in many applications.

  19. ERIC/RCS: Implications of the Ann Arbor Decision: Black English and the Reading Teacher.

    ERIC Educational Resources Information Center

    Monteith, Mary K.

    1980-01-01

    Presents 13 points about the relationship between Black English and reading; reports on books about Black English and teaching reading to Blacks; and suggests inservice materials for increasing teachers' knowledge about dialects. (JT)

  20. SCHOOL BUS GARAGES, 1966 REVISION.

    ERIC Educational Resources Information Center

    JOHNSON, HERBERT F.

    STANDARDS AND RECOMMENDATIONS ARE GIVEN FOR THE DESIGN AND CONSTRUCTION OF SCHOOL BUS GARAGES INCLUDING BRIEF DISCUSSIONS OF--(1) SITE DEVELOPMENT, (2) DESIGN AND CONSTRUCTION, AND (3) MECHANICAL (HEATING, PLUMBING, AND VENTILATION) AND ELECTRICAL FACTORS. (JT)

  1. Achondrogenesis

    MedlinePlus

    ... factor secretion and action. In: Sperling MA, ed. Pediatric Endocrinology . 4th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 10. Horton WA, Hecht JT. Disorders involving ion transporters. ... Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 697.

  2. Brain surgery - discharge

    MedlinePlus

    Gasco J, Mohanty A, Hanbali F, Patterson JT. Neurosurgery. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery . 19th ed. Philadelphia, PA: Elsevier Saunders; 2012: ...

  3. Dialysis centers - what to expect

    MedlinePlus

    ... in a treatment center. This article focuses on hemodialysis at a treatment center. ... JT, Blake PG, Ing TS, eds. Handbook of Dialysis . 5th ed. ... TA. Hemodialysis. In: Skorecki K, Chertow GM, Marsden PA, Taal ...

  4. Hepatitis

    MedlinePlus

    ... Gastrointestinal and Liver Disease. 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 90. Pawlotsky J-M. Chronic ... eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 149. Sjogren MH, Bassett JT. ...

  5. Course in Art and the Law

    ERIC Educational Resources Information Center

    Merryman, John Henry

    1974-01-01

    Justifies and describes a course offered at Stanford Law School in 1972 listing course objectives and outlining content which included focus on art looting, government and the arts, artist's rights in the work of art, consumer protection, and taxation. (JT)

  6. Another Look at the Tower of Hanoi

    ERIC Educational Resources Information Center

    Shwarger, Michael

    1977-01-01

    Through the use of sequences, geometric progressions and permutations, the author investigates some interesting and unusual questions concerning the number of moves required by each disc in solving the Tower of Hanoi puzzle. (JT)

  7. Towards a Portable Marxist Criticism: A Critique and Suggestion.

    ERIC Educational Resources Information Center

    Pfeil, Fred

    1980-01-01

    Reviews the recent work of Terry Eagleton and Raymond Williams, two proponents of Marxist literary theory. Considers the strengths and weaknesses of each writer, outlining an approach to Marxist literary criticism that blends the two theories. (JT)

  8. Cool's Clams Casino

    ERIC Educational Resources Information Center

    Cobey, Paul; Williams, David E.

    1977-01-01

    A mathematical game that reinforces basic multiplication facts, strengthens concepts of factors and multiples, and also provides arithmetic drill is described. Four variations of the game are also provided. (JT)

  9. The Politics of Composition: A Reply to John Rouse.

    ERIC Educational Resources Information Center

    Graff, Gerald

    1980-01-01

    Responds to an essay on "the politics of composition" by John Rouse (see EJ 209 264), who interpreted Mina Shaughnessy's teaching strategies as being political conditioning and suppressing student freedoms. Defends Shaughnessy's methods while seeking to refute Rouse's argument. (JT)

  10. Writing Away from Fear: Mina Shaughnessy and the Uses of Authority.

    ERIC Educational Resources Information Center

    Allen, Michael

    1980-01-01

    Responds to John Rouse's attack on Mina Shaughnessy's teaching strategies for composition instruction (see EJ 209 264). Offers personal experiences to illustrate the role of the basic writing teacher and the uses of authority in the basic writing classroom. (JT)

  11. The Vo-Ag Spring Educational Trip

    ERIC Educational Resources Information Center

    Fanning, T. D.

    1977-01-01

    A vocational agriculture teacher discusses values, planning procedures, and logistics of an annual 6-day trip in which 40 Future Farmers of America (FFA) members visit farms, ranches, agribusiness units, and other points of interest to rural oriented youth. (JT)

  12. Consumer-Homemaking for Teenage Parents

    ERIC Educational Resources Information Center

    Webb, Jackie Roger; Edenfield, Myrtice

    1977-01-01

    Describes a successful Jefferson County, Georgia, pilot program for teenage parents. The program for male and female high school students includes a counseling component and curriculum focus on prenatal-postnatal care, child care and development, and health services. (JT)

  13. The Accounting Curriculum in College

    ERIC Educational Resources Information Center

    Gustafson, George Axel

    1975-01-01

    In discussing the need for combination of theory and practice in the college accounting curriculum, the author presents a conceptual framework for the body of knowledge which teaches the student principles and puts them into practice through illustrations. (JT)

  14. A Rock Encyclopedia That Includes Rock Samples.

    ERIC Educational Resources Information Center

    Laznicka, Peter

    1981-01-01

    Described is a rock encyclopedia combining rock sample sets and encyclopedic word and picture entries which can be used as a realistic information resource for independent study or as a part of a course. (JT)

  15. Exploration of Home Economics Related Occupations in Clothing

    ERIC Educational Resources Information Center

    Thomas, Virginia F.; Plumb, Sandra

    1976-01-01

    A five-unit lesson plan is presented titled "Introduction to Careers in the Fashion Industry" which involved three sections of a ninth grade home economics class in an assembly line sewing experience in a clothing production factory. (JT)

  16. Impact of the third-strand orientation on the thermodynamic stability of the four-way DNA junction.

    PubMed

    Makube, N; Klump, H H

    2001-09-01

    The physical properties of a triple-helical DNA four-way junction J(T2T4) have been characterized by means of UV spectroscopy, CD spectroscopy, and differential scanning calorimetry (DSC). J(T2T4) is another four-way junction that was designed in addition to J(T1T3) (N. Makube and H. H. Klump (2000) Arch. Biochem. Biophys. 377, 31-42) to study the effects of third strands on the stability of the four-way junction with triple-helical arms. The pH titration curves illustrate the sequential folding of single strands to double-helical four-way junctions and finally the binding of third strands to their respective W-C duplexes. CD measurements confirm triplex formation under appropriate pH and ionic strength conditions. The CD spectra also suggest different melting patterns for the triple-helical arms of J(T2T4). The melting temperature as a function of pH or ionic strength characterizes the effect of the third strands on the structural stability. Increased sodium concentration and low pH conditions enhances and stabilizes the overall structure of the junction. The results also indicate that all triplexes in J(T2T4) are formed in the absence of salt and at low pH; however, the junction may, under these conditions, assume a conformation different from the one assumed in the presence of salt. Through the deconvolution of DSC data, the calorimetric enthalpies associated with melting of arms of the junctions were determined. The loops are designed to have the same enthalpic effect on the different arms. The stabilizing effect of the loops is more pronounced when those loops are shifted from arms 1 and 3 in J(T1T3) to arms 2 and 4 in J(T2T4) without changing any of the sequences. Overall, J(T2T4) is slightly more stable than J(T1T3). The differences can be attributed to sequence effects rather than structural effects. All the results illustrate that binding of the third strand in either of the two orientations 5'5'3' (J(T2T4)) or 5'3'3' (J(T1T3)) stabilizes the underlying

  17. EVA Systems Flight Controller Talks With Students

    NASA Video Gallery

    From NASA's International Space Station Mission Control Center, EVA Systems Flight Controller Sandy Fletcher participates in a Digital Learning Network (DLN) event with students from Northtowne Ele...

  18. Advanced laser shearography inspection of turbo-fan engine composite fan cases

    NASA Astrophysics Data System (ADS)

    Lape, Dale; Newman, John W.; Craig, David

    1995-07-01

    Shearography inspection techniques have been developed and implemented for the inspection of aluminum honeycomb turbofan aircraft engine fan cases for the JT15D-5D. Shearography has yielded improved sensitivity to unbonds and throughput over ultrasonic techniques formerly used in the production inspection. This paper discusses vacuum stress shearography, test method verification on the JT15D-5D fan case and shearography data correlation with destructive evaluation of test parts.

  19. Local Structure of La1-xSrxCoO3 determined from EXAFS and neutron PDF studies

    SciTech Connect

    Sundaram, N.; Jiang, Y.; Anderson, I. E.; Belanger, D. P.; Booth, C. H.; Bridges, F.; Mitchell, J. F.; Proffen, Th.; Zheng, H.

    2009-01-26

    The combined local structure techniques, extended x-ray absorption fine structure (EXAFS) and neutron pair distribution function analysis, have been used for temperatures 4<= T<= 330 K to rule out a large Jahn-Teller (JT) distortion of the Co-O bond in La1?xSrxCoO3 for a significant fraction of Co sites (x<= 0.35), indicating few, if any, JT-active, singly occupied eg Co sites exist.

  20. Gate control of ferromagnetic insulating phase in lightly-doped La0.875Sr0.125MnO3-δ film

    NASA Astrophysics Data System (ADS)

    Kuang, H.; Wang, J.; Hu, F. X.; Zhao, Y. Y.; Liu, Y.; Wu, R. R.; Sun, J. R.; Shen, B. G.

    2016-02-01

    The electric field effect on the lightly doped La0.875Sr0.125MnO3-δ (LSMO) thin film in electric double-layer transistors was investigated by measuring transport properties of the film under various gate voltages. It was found that the positive gate bias leads to an increase of the charge-orbital ordering (COO) transition temperature and a decrease of the Curie temperature TC, indicating the suppression of ferromagnetic metal (FMM) phases and preference of COO/ferromagnetic insulator (FMI) with the hole depletion by gate bias. Such different electric field effects can be ascribed to the weakening of the ferromagnetic interaction and enhancement of Jahn-Teller (JT) distortion caused by the transformation of JT inactive Mn4+-ions to JT active Mn3+-ions. Moreover, a step-like increase in the high temperature region of the ρ-T curve, which is related to the transition of cooperative JT distortion, was found to develop with increasing the positive bias, indicating that the cooperative JT distorted phase is stabilized by the depletion of holes in LSMO film. These results demonstrate that the modulation of holes via electric field strongly affects the balance between energy gains of different interactions and thus produce different effects on the competing FMI, FMM, and cooperative JT distorted phases in LSMO film.

  1. Vibronic Analysis of the widetilde{A}^2 E^'' State of NO_3 Radical

    NASA Astrophysics Data System (ADS)

    Codd, Terrance J.; Roudjane, Mourad; Chen, Ming-Wei; Miller, Terry A.

    2013-06-01

    The nitrate radical is a key reactant in atmospheric chemistry leading to the formation of acid rain and is the primary oxidant in the night sky. The widetilde{A}^2 E^'' state of NO_3 is doubly degenerate and is therefore subject to Jahn-Teller (JT) coupling through the degenerate in-plane stretch and bend modes (ν_3 and ν_4 respectively). We have taken a moderate resolution CRDS spectrum of the widetilde{A}^2 E^''-widetilde{X}^2 A_2' transition of the NO_3 radical under jet-cooled conditions. We resolve ˜20 vibronic transitions and are able to assign many using an independent anharmonic oscillator model as was presented previously. In order to gain a deeper understanding of the nature of the JT effect in this electronic state we have performed a vibronic analysis including linear and quadratic JT coupling terms for ν_3 and ν_4 and possible bilinear coupling between the totally symmetric stretch, ν_1, and ν_4. We conclude that the JT coupling in ν_4 is quite weak. Satisfactory spectral fits can be obtained assuming weak JT coupling for ν_3 also, though there is some evidence of strong JT coupling for ν_3 and the strengths and weaknesses of each case are discussed. Codd, T. et al. 67^{th} Int. Symp. Molec. Spec. (2012)}

  2. Properties of Gas Mixtures and Their Use in Mixed-Refrigerant Joule-Thomson Refrigerators

    NASA Astrophysics Data System (ADS)

    Luo, E.; Gong, M.; Wu, J.; Zhou, Y.

    2004-06-01

    The Joule-Thomson (J-T) effect has been widely used for achieving low temperatures. In the past few years, much progress has been made in better understanding the working mechanism of the refrigeration method and in developing prototypes for different applications. In this talk, there are three aspects of our research work to be discussed. First, some special thermal properties of the mixtures for achieving liquid nitrogen temperature range will be presented. Secondly, some important conclusions from the optimization of various mixed-refrigerant J-T cycles such as a simple J-T cycle and an auto-cascade mixed-refrigerant J-T cycle will be presented. Moreover, an auto-cascade, mixed-refrigerant J-T refrigerator with a special mixture capable of achieving about 50K will be mentioned. Finally, various prototypes based on the mixed-refrigerant refrigeration technology will be described. These applications include miniature J-T cryocoolers for cooling infrared detectors and high-temperature superconducting devices, cryosurgical knife for medical treatment, low-temperature refrigerators for biological storage and so forth. The on-going research work and unanswered questions for this technology will be also discussed.

  3. SU-E-T-187: Feasibility Study of Stereotactic Liver Radiation Therapy Using Multiple Divided Partial Arcs in Volumetric Modulated Arc Therapy

    SciTech Connect

    Lin, Y; Ozawa, S; Tsegmed, U; Nakashima, T; Shintaro, T; Ochi, Y; Kawahara, D; Kimura, T; Nagata, Y

    2014-06-01

    Purpose: To verify volumetric modulated arc therapy (VMAT) using flattening filter free (FFF) mode with jaw tracking (JT) feature for single breath hold as long as 15 s per arc in liver stereotactic body radiation therapy (SBRT) against intensity modulated radiation therapy (IMRT) FFF-JT. Methods: Ten hepatocellular carcinoma (HCC) cases were planned with 10 MV FFF using Pinnacle3 treatment planning system which delivered by TrueBeam to administer 48 Gy/ 4 fractions. Eight non-coplanar beams were assigned to IMRT using step-and-shoot technique. For VMAT, two or three non-coplanar partial arcs (up to 180 degrees) were further divided into subarcs with gantry rotation less than 80 degrees to limit delivery time within 15 s. Dose distributions were verified using OCTAVIUS II system and pass rates were evaluated using gamma analysis with criteria of 3%/3 mm at threshold of 5% to the maximum dose. The actual irradiation time was measured. Results: The VMAT-FFF-JT of partial-arcs with sub-divided arcs was able to produce a highly conformal plan as well as IMRT-FFF-JT. Isodose lines and DVH showed slight improvement in dosimetry when JT was employed for both IMRT and VMAT. Consequently, VMAT-FFF-JT was superior in reducing the dose to liver minus gross tumor volume. VMAT-FFF-JT has shorter total treatment time compared with 3D conformal radiation therapy (3D-CRT) FFF because the gantry was rotated simultaneously with the beam delivery in VMAT. Moreover, due to the small and regular shape of HCC, VMAT-FFF-JT offered less multileaf collimator motion, thus the interplay effect is expected to be reduced. The patient specific QA of IMRT and VMAT acquired the pass rates higher than 90%. Conclusion: VMAT-FFF-JT could be a promising technique for liver SBRT as the sub-divided arcs method was able to accommodate a single breath hold irradiation time of less than 15 s without deterioration of the dose distribution compared with IMRT-FFF-JT.

  4. Search for WIMPs with NaI(Tl) detectors at Oto Cosmo Observatory

    NASA Astrophysics Data System (ADS)

    Yoshida, S.; Ejiri, H.; Fushimi, K.; Hayashi, K.; Kishimoto, T.; Kudomi, N.; Kume, K.; Kuramoto, H.; Matsuoka, K.; Ohsumi, H.; Takahisa, K.; Tsujimoto, Y.; Umehara, S.

    2003-06-01

    The cold dark matter search has been carried out at Oto Cosmo Observatory with the large volume NaI(Tl) scintillators of ELEGANT V(ELE-V). The new limits on WIMPs could be obtained by the analysis of the annual modulation. Recently, the performance of NaI(Tl) detector in ELE-V was successfully improved. these are also discussed.

  5. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Harvested Coral Reef Taxa: Family name Local name English common name Scientific name Acanthuridae.... Acanthuridae (Surgeonfishes) kala holo black tongue unicornfish Naso hexacanthus. Kala whitemargin unicornfish... Melichthys vidua. humuhumu `ele`ele black triggerfish Melichthys niger. humuhumu nukunuku apua`a...

  6. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Harvested Coral Reef Taxa: Family name Local name English common name Scientific name Acanthuridae.... Acanthuridae (Surgeonfishes) kala holo black tongue unicornfish Naso hexacanthus. Kala whitemargin unicornfish... Melichthys vidua. humuhumu `ele`ele black triggerfish Melichthys niger. humuhumu nukunuku apua`a...

  7. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Harvested Coral Reef Taxa: Family name Local name English common name Scientific name Acanthuridae.... Acanthuridae (Surgeonfishes) kala holo black tongue unicornfish Naso hexacanthus. Kala whitemargin unicornfish... Melichthys vidua. humuhumu `ele`ele black triggerfish Melichthys niger. humuhumu nukunuku apua`a...

  8. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Harvested Coral Reef Taxa: Family name Local name English common name Scientific name Acanthuridae.... Acanthuridae (Surgeonfishes) kala holo black tongue unicornfish Naso hexacanthus. Kala whitemargin unicornfish... Melichthys vidua. humuhumu `ele`ele black triggerfish Melichthys niger. humuhumu nukunuku apua`a...

  9. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Harvested Coral Reef Taxa: Family name Local name English common name Scientific name Acanthuridae.... Acanthuridae (Surgeonfishes) kala holo black tongue unicornfish Naso hexacanthus. Kala whitemargin unicornfish... Melichthys vidua. humuhumu `ele`ele black triggerfish Melichthys niger. humuhumu nukunuku apua`a...

  10. ICT Support for Collaborative Learning--A Tale of Two Cities

    ERIC Educational Resources Information Center

    Consiglio, Teresa; van der Veer, Gerrit C.

    2013-01-01

    Based on experiences in teaching service design in a blended learning context, we developed an electronic learning environment (ELE) including features that turned out to be suitable for learners from different cultures. We used this ELE in Italy and in China. Students were guided through collaborative learning and mutual teaching. Students were…

  11. Quantifying the Effects of Higher Order Jahn-Teller Coupling Terms on a Quadratic Jahn-Teller Hamiltonian in the Case of NO_3 and Li_3.

    NASA Astrophysics Data System (ADS)

    Tran, Henry; Stanton, John F.; Miller, Terry A.

    2016-06-01

    The Jahn-Teller (JT) effect represents an enormous complication in the understanding of many molecules. We have been able to assign ˜20 vibronic bands in the tilde{A}^2E'' ← tilde{X}^2A_2' transition of NO_3 and determine the linear and quadratic JT coupling terms for ν_3 and ν_4, indicating strong and weak JT coupling along these modes respectively. It was found that the experimental results quantitatively disagree with ones determined from a vibronic Hamiltonian based on high-level ab-initio theory. Typical analyses of experimental data use the quadratic JT Hamiltonian because limited measured levels tend to allow fitting only to coupling terms up to quadratic JT coupling. Hence, these analyses may neglect key contributions from cubic and quartic terms. To quantify this limitation, we have fit artificial spectra calculated with up to fourth order terms in the potential using a quadratic JT Hamiltonian and analyzed the results. The parameters chosen for this analysis are determined from ab-initio potentials for the tilde{A} state of NO_3 and tilde{X} state of Li_3 to gain further insight on these molecules. Our initial results concerning the limitations of the quadratic JT Hamiltonian will be presented. T. Codd, M.-W. Chen, M. Roudjane, J. F. Stanton, and T. A. Miller. Jet cooled cavity ringdown spectroscopy of the tilde{A}^2E'' ← tilde{X}^2A'_2 Transition of the NO_3 Radical. J. Chem. Phys., 142:184305, 2015

  12. Roseovarius nanhaiticus sp. nov., a member of the Roseobacter clade isolated from marine sediment.

    PubMed

    Wang, Baojiang; Sun, Fengqin; Lai, Qiliang; Du, Yaping; Liu, Xiupian; Li, Guangyu; Luo, Jie; Shao, Zongze

    2010-06-01

    An aerobic, Gram-staining-negative, rod or ovoid-shaped bacterial isolate, strain NH52J(T), was isolated from a sandy sediment sample from the South China Sea. Strain NH52J(T) exhibited tumbling motility, formed beige or faint pink colonies, gave a positive reaction in tests for catalase and oxidase and required NaCl for growth. Optimal growth was observed at pH 7.8-9.3, at 30 degrees C and in the presence of 2.0-4.0 % (w/v) NaCl. The novel strain did not synthesize bacteriochlorophyll a, and the DNA G+C content was 62 %. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(18 : 1)omega7c 11-methyl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH52J(T) was affiliated to the genus Roseovarius of the class Alphaproteobacteria. Roseovarius pacificus and Roseovarius aestuarii were the most closely related recognized species to strain NH52J(T) with 16S rRNA gene sequence similarity values of 95.0 and 95.7 %, respectively. Sequence similarity values between strain NH52J(T) and other phylogenetically related species were all below 95.0 %. Based on the phenotypic, chemotaxonomic and phylogenetic data presented, strain NH52J(T) is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius nanhaiticus sp. nov. is proposed. The type strain is NH52J(T) (=LMG 24840(T)=CCTCC AB 208317(T)=MCCC 1A03543(T)).

  13. Microwave Accelerated Green Synthesis of Stable Silver Nanoparticles with Eucalyptus globulus Leaf Extract and Their Antibacterial and Antibiofilm Activity on Clinical Isolates.

    PubMed

    Ali, Khursheed; Ahmed, Bilal; Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A; Musarrat, Javed

    2015-01-01

    A simple and rapid microwave assisted method of green synthesis of silver nanoparticles (AgNPs) was developed using aqueous leaf extract of Eucalyptus globulus(ELE), and their antibacterial and antibiofilm potential investigated. With this aim, the aqueous solutions of ELE and AgNO3(1 mM) were mixed (1:4 v/v), and microwave irradiated at 2450 Mhz, for 30 sec. The instant color change of the ELE-AgNO3 mixture from pale yellow to dark brown indicated ELE-AgNPs synthesis. The intensity of peak at 428 nm in UV-Vis spectra, due to the surface plasmon resonance of AgNPs, varied with the amount of ELE, AgNO3 concentration, pH and time of incubation. The biosynthesized ELE-AgNPs were characterized by UV-visible spectroscopy, XRD, TEM, SEM-EDX, FTIR and TGA analyses. The size of ELE-AgNPs was determined to be in range of 1.9-4.3 nm and 5-25 nm, with and without microwave treatment, respectively. SEM exhibited the capping of AgNPs with the ELE constituents, and validated by FTIR analysis. The FTIR data revealed the presence of plant organic constituents and metabolites bound to ELE-AgNPs, which contributes for their stability. The antimicrobial activity of ELE-AgNPs was assessed by growth and biofilm inhibition of extended spectrum β-lactamase (ESBL) producing Pseudomonas aeruginosa, Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) clinical bacterial isolates. The results demonstrated that S. aureus were more sensitive to ELE-AgNPs than E. coli and P. aeruginosa. MRSA exhibited higher sensitive than MSSA, whereas P. aeruginosa were more sensitive than E. coli to ELE-AgNPs treatment. Also, significant (83 ± 3% and 84 ± 5%) biofilm inhibition was observed in case of S. aureus and P. aeruginosa, respectively. The results elucidated environmentally friendly, economical and quick method for production of colloidal bio-functionalized ELE-AgNPs, for effectual clinical applications, as broad spectrum

  14. Microwave Accelerated Green Synthesis of Stable Silver Nanoparticles with Eucalyptus globulus Leaf Extract and Their Antibacterial and Antibiofilm Activity on Clinical Isolates.

    PubMed

    Ali, Khursheed; Ahmed, Bilal; Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A; Musarrat, Javed

    2015-01-01

    A simple and rapid microwave assisted method of green synthesis of silver nanoparticles (AgNPs) was developed using aqueous leaf extract of Eucalyptus globulus(ELE), and their antibacterial and antibiofilm potential investigated. With this aim, the aqueous solutions of ELE and AgNO3(1 mM) were mixed (1:4 v/v), and microwave irradiated at 2450 Mhz, for 30 sec. The instant color change of the ELE-AgNO3 mixture from pale yellow to dark brown indicated ELE-AgNPs synthesis. The intensity of peak at 428 nm in UV-Vis spectra, due to the surface plasmon resonance of AgNPs, varied with the amount of ELE, AgNO3 concentration, pH and time of incubation. The biosynthesized ELE-AgNPs were characterized by UV-visible spectroscopy, XRD, TEM, SEM-EDX, FTIR and TGA analyses. The size of ELE-AgNPs was determined to be in range of 1.9-4.3 nm and 5-25 nm, with and without microwave treatment, respectively. SEM exhibited the capping of AgNPs with the ELE constituents, and validated by FTIR analysis. The FTIR data revealed the presence of plant organic constituents and metabolites bound to ELE-AgNPs, which contributes for their stability. The antimicrobial activity of ELE-AgNPs was assessed by growth and biofilm inhibition of extended spectrum β-lactamase (ESBL) producing Pseudomonas aeruginosa, Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) clinical bacterial isolates. The results demonstrated that S. aureus were more sensitive to ELE-AgNPs than E. coli and P. aeruginosa. MRSA exhibited higher sensitive than MSSA, whereas P. aeruginosa were more sensitive than E. coli to ELE-AgNPs treatment. Also, significant (83 ± 3% and 84 ± 5%) biofilm inhibition was observed in case of S. aureus and P. aeruginosa, respectively. The results elucidated environmentally friendly, economical and quick method for production of colloidal bio-functionalized ELE-AgNPs, for effectual clinical applications, as broad spectrum

  15. Microwave Accelerated Green Synthesis of Stable Silver Nanoparticles with Eucalyptus globulus Leaf Extract and Their Antibacterial and Antibiofilm Activity on Clinical Isolates

    PubMed Central

    Ali, Khursheed; Ahmed, Bilal; Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A.; Musarrat, Javed

    2015-01-01

    A simple and rapid microwave assisted method of green synthesis of silver nanoparticles (AgNPs) was developed using aqueous leaf extract of Eucalyptus globulus(ELE), and their antibacterial and antibiofilm potential investigated. With this aim, the aqueous solutions of ELE and AgNO3(1 mM) were mixed (1:4 v/v), and microwave irradiated at 2450 Mhz, for 30 sec. The instant color change of the ELE-AgNO3 mixture from pale yellow to dark brown indicated ELE-AgNPs synthesis. The intensity of peak at 428 nm in UV-Vis spectra, due to the surface plasmon resonance of AgNPs, varied with the amount of ELE, AgNO3 concentration, pH and time of incubation. The biosynthesized ELE-AgNPs were characterized by UV-visible spectroscopy, XRD, TEM, SEM-EDX, FTIR and TGA analyses. The size of ELE-AgNPs was determined to be in range of 1.9–4.3 nm and 5-25 nm, with and without microwave treatment, respectively. SEM exhibited the capping of AgNPs with the ELE constituents, and validated by FTIR analysis. The FTIR data revealed the presence of plant organic constituents and metabolites bound to ELE-AgNPs, which contributes for their stability. The antimicrobial activity of ELE-AgNPs was assessed by growth and biofilm inhibition of extended spectrum β-lactamase (ESBL) producing Pseudomonas aeruginosa, Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) clinical bacterial isolates. The results demonstrated that S. aureus were more sensitive to ELE-AgNPs than E. coli and P. aeruginosa. MRSA exhibited higher sensitive than MSSA, whereas P. aeruginosa were more sensitive than E. coli to ELE-AgNPs treatment. Also, significant (83 ± 3% and 84 ± 5%) biofilm inhibition was observed in case of S. aureus and P. aeruginosa, respectively. The results elucidated environmentally friendly, economical and quick method for production of colloidal bio-functionalized ELE-AgNPs, for effectual clinical applications, as broad spectrum

  16. Pressure drop characteristics of cryogenic mixed refrigerant at macro and micro channel heat exchangers

    NASA Astrophysics Data System (ADS)

    Baek, Seungwhan; Jeong, Sangkwon; Hwang, Gyuwan

    2012-12-01

    Mixed Refrigerant-Joule Thomson (MR-JT) refrigerators are widely used in various kinds of cryogenic systems these days. The temperature glide effect is one of the major features of using mixed refrigerants since a recuperative heat exchanger in a MR-JT refrigerator is utilized for mostly two-phase flow. Although a pressure drop estimation for a multi-phase and multi-component fluid in the cryogenic temperature range is necessarily required in MR-JT refrigerator heat exchanger designs, it has been rarely discussed so far. In this paper, macro heat exchangers and micro heat exchangers are compared in order to investigate the pressure drop characteristics in the experimental MR-JT refrigerator operation. The tube in tube heat exchanger (TTHE) is a well-known macro-channel heat exchanger in MR-JT refrigeration. Printed Circuit Heat Exchangers (PCHEs) have been developed as a compact heat exchanger with micro size channels. Several two-phase pressure drop correlations are examined to discuss the experimental pressure measurement results. The result of this paper shows that cryogenic mixed refrigerant pressure drop can be estimated with conventional two-phase pressure drop correlations if an appropriate flow pattern is identified.

  17. β-Elemene Inhibits Cell Proliferation by Regulating the Expression and Activity of Topoisomerases I and IIα in Human Hepatocarcinoma HepG-2 Cells

    PubMed Central

    Gong, Min; Liu, Ying; Zhang, Jian; Gao, Ya-jie; Zhai, Ping-ping; Su, Xi; Li, Xiang; Li, Yan; Hou, Li; Cui, Xiao-nan

    2015-01-01

    Objective. To investigate the effects of β-Elemene (β-ELE) on the proliferation, apoptosis, and topoisomerase I (TOPO I) and topoisomerase IIα (TOPO IIα) expression and activity of human hepatocarcinoma HepG-2 cells. Methods. After treatment with β-ELE, morphological alterations of HepG-2 cells were observed under an inverted microscope. Cell proliferation was assessed using an MTT assay, cell cycles were analyzed using flow cytometry, and apoptosis was detected by Annexin V/PI staining. The expression of TOPO I and TOPO IIα was analyzed by Western blot techniques, and their activity was measured using the TOPO I-mediated, supercoiled pBR322 DNA relaxation and TOPO IIα-mediated Kinetoplast DNA (kDNA) decatenation assays, respectively. Supercoiled pBR322 and kDNA were also used to determine the direct effect of β-ELE on DNA breaks. Results. β-ELE significantly inhibited HepG-2 cell proliferation in a dose- and time-dependent manner. β-ELE also induced tumor cell arrest at S phase, induced cell apoptosis, and downregulated the protein expression of TOPO I and TOPO IIα in a dose-dependent manner. β-ELE also inhibited TOPO I- and TOPO IIα-mediated DNA relaxation but did not directly induce DNA breakage at any concentration. Conclusion. β-ELE could inhibit the proliferation of HepG-2 cells and interfere with the expression and activity of TOPO I and TOPO IIα. PMID:26221582

  18. Synchronization of networked Jahn-Teller systems in SQUIDs

    NASA Astrophysics Data System (ADS)

    Gül, Yusuf

    2016-06-01

    We consider the nonlinear effects in a Jahn-Teller (JT) system of two coupled resonators interacting simultaneously with a flux qubit using coupled SQUIDs. A two-frequency description of JT system that inherits the networked structure of both nonlinear Josephson junctions and harmonic oscillators is employed to describe the synchronous structures in a multifrequency scheme. Eigenvalue spectrum is used to show the switch between the effective single mode and two mode configuration in terms of frequency difference. The Rabi supersplitting is investigated by the spectral response of JT systems in different coupling regimes. Second-order coherence functions are employed to investigate antibunching effects in resonator mode. Synchronous structure between correlations of privileged mode and qubit is obtained in localization-delocalization and photon blockade regime controlled by the population imbalance.

  19. Potential improvements in turbofan engine fuel economy

    NASA Technical Reports Server (NTRS)

    Hines, R. W.; Gaffin, W. O.

    1976-01-01

    The method developed for initial evaluation of possible performance improvements in the NASA Aircraft Energy Efficiency Program, directed toward improving the fuel economy of turbofan engines, is outlined, and results of the evaluation of 100 candidate engine modifications are presented. The study indicates that fuel consumption improvements of as much as 5% may be possible in current JT3D, JT8D, and JT9D turbofan engines. Aerodynamic, thermodynamic, material, and structural advances are expected to yield fuel consumption improvements on the order of 10 to 15% in advanced turbofan engines, with the greatest improvement stemming from significantly higher cycle pressure ratios. Higher turbine temperature and fan bypass ratios are also expected to contribute to fuel conservation.

  20. Development of 1K-class Joule-Thomson cryocooler for next-generation astronomical mission

    NASA Astrophysics Data System (ADS)

    Sato, Yoichi; Sawada, Kenichiro; Shinozaki, Keisuke; Sugita, Hiroyuki; Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Nakagawa, Takao; Tsunematsu, Shoji; Ootsuka, Kiyomi; Narasaki, Katsuhiro

    2016-03-01

    This paper reports on the development of a 1K-class Joule-Thomson (JT) cryocooler in Japan for application to upcoming next-generation astronomy missions. In this development, engineering models (EMs) were designed and manufactured for verification tests. The survival of the models in the mechanical and thermal vacuum environment tests of the JT compressors was proven to be possible with stable compression performance. In addition, the electromagnetic noise and disturbance force associated with the JT compressors were evaluated. Gas analysis showed that the estimated total amount of CO2 gas contaminant was less than the getter capacity for the required lifetime. A nominal cooling power of 10 mW at 1.7 K was verified using the EM test units.

  1. Jahn-Teller and pseudo-Jahn-Teller effects in trifluoromethane radical cation

    NASA Astrophysics Data System (ADS)

    Ghanta, Susanta

    2016-08-01

    Jahn-Teller (JT) and pseudo-Jahn-Teller (PJT) effects in the ground, first and second excited electronic states of the trifluoromethane radical cation are theoretically examined here. Extensive ab initio computation of electronic potential energy surfaces and their coupling surfaces are performed. Full quantum dynamics are obtained by both time-independent and time-dependent quantum mechanical methods. This system belongs to (E+A)⊗e JT-PJT family. Our results compare well with the experimental data. JT interactions are fairly strong in the second excited B˜2 E electronic state and the PJT interaction between A˜2A2 - B˜2 E electronic states is stronger which cause an increase of the spectral line density of the vibronic spectrum.

  2. Preliminary experimental and numerical study of transient characteristics for a Joule-Thomson cryocooler

    NASA Astrophysics Data System (ADS)

    Chou, F.-C.; Pai, C.-F.; Chien, S. B.; Chen, J. S.

    To establish a tool for computer-aided design, a preliminary experimental and numerical study of transient characteristics for a Joule-Thomson (J-T) cryocooler is developed in the present work. A simplified transient one-dimensional model of momentum and energy transport is used to simulate the flow and heat transfer characteristics. The computational results for cool-down time agree with the experimental data. The transient temperature variations of high pressure gas, tube wall, low pressure gas, glass Dewar and mandrel at the grid point near the valve exit are shown. From the spatial temperature distributions of high and low pressure gases along the finned tube at the moment of cool-down, it is proposed that the J-T cooler currently used may be reduced in terms of both size and weight; factors which are very important in a miniature J-T cryocooler.

  3. Effect of dynamics on the elastic softening of vacancies in Si

    SciTech Connect

    Shirai, Koun; Ishisada, Jun

    2014-02-21

    Recently, elastic softening at temperatures below 20 K has been observed in nondoped floating zone silicon. From the experimental analysis, it has been suggested that this softening is caused by an intrinsic vacancy defect through the Jahn-Teller (JT) effect. We have theoretically studied the relations between softening and the vacancies. The ground state of the JT distortion is stiff. However, by considering atomistic dynamical and anharmonic effects, it is found that low-energy excitations exist in the E-mode distortion and that different polarizations of the E-distortion can be easily interchanged. The calculated energy barriers for the reorientation of JT distortions are consistent with other experiments and calculations. This low-lying mode can be the cause of softening in the elastic responses.

  4. Evidence for a Jahn-Teller distortion in the CMR layered manganite La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7}

    SciTech Connect

    Louca, D.; Kwei, G.H.; Mitchell, J.F.

    1998-12-31

    The changes with temperature in the crystallographic structure of the two-layered La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7}, are on average quite small but the atomic pair density function analysis of pulsed neutron diffraction data shows that the lattice is locally distorted in accordance with the change in the transport properties. In particular, while no Jahn-Teller (JT) distortion is expected in the layered compounds because the octahedral bilayers are almost cubic, lattice distortions attributed to a large JT effect are present and are of comparable magnitude as in the cubic perovskite system. This could in turn explain the similarity in their properties. The number of the JT distorted sites is reduced with temperature concomitantly with the decrease in resistivity of the ab-plane.

  5. Improved components for engine fuel savings

    NASA Technical Reports Server (NTRS)

    Antl, R. J.; Mcaulay, J. E.

    1980-01-01

    NASA programs for developing fuel saving technology include the Engine Component Improvement Project for short term improvements in existing air engines. The Performance Improvement section is to define component technologies for improving fuel efficiency for CF6, JT9D and JT8D turbofan engines. Sixteen concepts were developed and nine were tested while four are already in use by airlines. If all sixteen concepts are successfully introduced the gain will be fuel savings of more than 6 billion gallons over the lifetime of the engines. The improvements include modifications in fans, mounts, exhaust nozzles, turbine clearance and turbine blades.

  6. MATE program: Erosion resistant compressor airfoil coating, volume 2

    NASA Technical Reports Server (NTRS)

    Freling, Melvin

    1987-01-01

    The performance of candidate erosion resistant airfoil coatings installed in ground tested experimental JT8D and JT9D engines and subjected to cyclic endurance at idle, takeoff and intermediate power conditions has been evaluated. Engine tests were terminated prior to the scheduled 1000 cycles of endurance test due to high cycle fatigue fracture of the Gator-Gard plasma sprayed 88WC-12Co coating on titanium alloy airfoils. Coated steel (AMS5616) and nickel base alloy (Incoloy 901) performed well in both engine tests. Post test airfoil analyses consisted of binocular, scanning electron microscope and metallographic examinations.

  7. Fluctuating pressures on fan blades of a turbofan engine: Static and wind-tunnel investigations

    NASA Astrophysics Data System (ADS)

    Schoenster, J. A.

    1982-03-01

    To investigate the fan noise generated from turbofan engines, miniature pressure transducers were used to measure the fluctuating pressure on the fan blades of a JT15D engine. Tests were conducted with the engine operating on an outdoor test stand and in a wind tunnel. It was found that a potential flow interaction between the fan blades and six, large support struts in the bypass duct is a dominant noise source in the JT15D engine. Effects of varying fan speed and the forward speed on the blade pressure are also presented.

  8. Analysis of turbofan engine performance deterioration and proposed follow-on tests

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.; Kruckenberg, H. D.; Toomey, E. H.

    1975-01-01

    Data and engine parts on in-service JT3D and JT8D engines were analyzed and documented relative to engine deterioration. It is concluded that the fan-compressor system of these engines contributes to the long term engine deterioration. An engine test and instrumentation plan was formulated for a proposed follow-on program. The goal of this program is to verify the above conclusion and to attempt to identify more precisely which components of the fan-compressor system are at fault.

  9. NASA/Pratt and Whitney experimental clean combustor program: Engine test results

    NASA Technical Reports Server (NTRS)

    Roberts, R.; Fiorentino, A. J.; Greene, W.

    1977-01-01

    A two-stage vorbix (vortex burning and mixing) combustor and associated fuel system components were successfully tested in an experimental JT9D engine at steady-state and transient operating conditions, using ASTM Jet-A fuel. Full-scale JT9D experimental engine tests were conducted in a phase three aircraft experimental clean combustor program. The low-pollution combustor, fuel system, and fuel control concepts were derived from phase one and phase two programs in which several combustor concepts were evaluated, refined, and optimized in a component test rig. Significant pollution reductions were achieved with the combustor which meets the performance, operating, and installation requirements of the engine.

  10. Statistical mechanical lattice models of endohedral and exohedral xenon adsorption in carbon nanotubes and comparison with Monte-Carlo simulations

    NASA Astrophysics Data System (ADS)

    Dunne, Lawrence J.; Manos, George; Rekabi, Mahdi

    2009-01-01

    Adsorption of xenon in carbon nanotubes has been investigated by Kuznetsova et al. [A. Kuznetsova, J.T. Yates Jr., J. Liu, R.E. Smalley, J. Chem. Phys. 112 (2000) 9590] and Simonyan et al. [V. Simonyan, J.K. Johnson, A Kuznetsova, J.T. Yates Jr., J. Chem. Phys. 114 (2001) 4180] where endohedral adsorption isotherms show a step-like structure. A matrix method is used for calculation of the statistical mechanics of a lattice model of xenon endohedral adsorption which reproduces the isotherm structure while exohedral adsorption is treated by mean-field theory.

  11. Test-engine and inlet performance of an aircraft used for investigating flight effects on fan noise

    NASA Astrophysics Data System (ADS)

    Golub, R. A.; Preisser, J. S.

    1984-04-01

    As part of the NASA Flight Effects on Fan Noise Program, a Grumman OV-1B Mohawk aircraft was modified to carry a modified and instrumented Pratt & Whitney JT15D-1 turbofan engine. Onboard flight data, together with simultaneously measured farfield acoustic data, comprise a flight data base to which JT15D-1 static and wind-tunnel data are compared. The overall objective is to improve the ability to use ground-based facilities for the prediction of flight inlet radiated noise. This report describes the hardware and presents performance results for the research engine.

  12. Polar antiferromagnets produced with orbital order.

    PubMed

    Ogawa, Naoki; Ogimoto, Yasushi; Ida, Yoshiaki; Nomura, Yusuke; Arita, Ryotaro; Miyano, Kenjiro

    2012-04-13

    Polar states are realized in pseudocubic manganite films fabricated on high-index substrates, in which a Jahn-Teller (JT) distortion remains an active variable. Several types of orbital orders (OOs) were found to develop large optical second harmonics, signaling broken-inversion symmetry distinct from their bulk forms and films on (100) substrates. The observed symmetry lifting and first-principles calculation both indicate that the modified JT q2 mode drives Mn-site off centering, which can be controlled by a magnetic-field-induced phase transition via a coupling of OO and spin orders.

  13. MATE program: erosion resistant compressor airfoil coating, volume 2. Final report

    SciTech Connect

    Freling, M.

    1987-03-01

    The performance of candidate erosion resistant airfoil coatings installed in ground tested experimental JT8D and JT9D engines and subjected to cyclic endurance at idle, takeoff and intermediate power conditions has been evaluated. Engine tests were terminated prior to the scheduled 1000 cycles of endurance test due to high cycle fatigue fracture of the Gator-Gard plasma sprayed 88WC-12Co coating on titanium alloy airfoils. Coated steel (AMS5616) and nickel base alloy (Incoloy 901) performed well in both engine tests. Post test airfoil analyses consisted of binocular, scanning electron microscope and metallographic examinations.

  14. Test-engine and inlet performance of an aircraft used for investigating flight effects on fan noise

    NASA Technical Reports Server (NTRS)

    Golub, R. A.; Preisser, J. S.

    1984-01-01

    As part of the NASA Flight Effects on Fan Noise Program, a Grumman OV-1B Mohawk aircraft was modified to carry a modified and instrumented Pratt & Whitney JT15D-1 turbofan engine. Onboard flight data, together with simultaneously measured farfield acoustic data, comprise a flight data base to which JT15D-1 static and wind-tunnel data are compared. The overall objective is to improve the ability to use ground-based facilities for the prediction of flight inlet radiated noise. This report describes the hardware and presents performance results for the research engine.

  15. Local structure of La1-xSrxCoO3 determined from EXAFS and neutron PDF studies

    SciTech Connect

    Proffen, Thomas; Sundaram, Nalini; Jiang, Y; Anderson, Ingrid; Belanger, D P; Booth, C H; Bridges, F; Mitchell, J F; Zheng, H

    2008-01-01

    The combined local structure techniques, extended X-ray absorption fine struture (EXAFS) and neutron pair distribution function (PDF) analysis, have been used for temperatures 4 {<=} T {<=} 330 K to rule out a large Jahn-Teller (J-T) distortion of the Co-O bond in La{sub 1-x}Sr{sub x}CoO{sub 3} for a significant fraction of Co sites (x {<=} 0.35), indicating few, if any, J-T active, single-occupied e{sub g} Co sites exist.

  16. Nacelle Aerodynamic and Inertial Loads (NAIL) project. Appendix B

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The testing was conducted on the Boeing-owned 747 RA001 test bed airplane during the concurrent 767/JT9D-7R4 engine development program. Following a functional check flight conducted from Boeing Field International (BFI) on 3 October 1980, the airplane and test personnel were ferried to Valley Industrial Park (GSG) near Glasgow, Montana, on 7 October 1980. The combined NAL and 7670JT9D-7R4 test flights were conducted at the Glasgow remote test site, and the airplane was returned to Seattle on 26 October 1980.

  17. NASA's Fiscal Year 2012 Budget Request

    NASA Video Gallery

    NASA announced an $18.7 billion budget request for fiscal year 2012 that supports a reinvigorated path of innovation, technological development and scientific discovery. The budget supports all ele...

  18. Theoretical investigations into the electronic structures and electron transport properties of fluorine and carbonyl end-functionalized quarterthiophenes.

    PubMed

    Li, Qian; Duan, Yuai; Gao, Hong-Ze; Su, Zhong-Мin; Geng, Yun

    2015-06-01

    In this work, we concentrate on systematic investigation on the fluorination and carbonylation effect on electron transport properties of thiophene-based materials with the aim of seeking and designing electron transport materials. Some relative factors, namely, frontier molecular orbital (FMO), vertical electron affinity (VEA), electron reorganization energy (λele), electron transfer integral (tele), electron drift mobility (μele) and band structures have been calculated and discussed based on density functional theory. The results show that the introduction of fluorine atoms and carbonyl group especially for the latter could effectively increase EA and reduce λele, which is beneficial to the improvement of electron transport performance. Furthermore, these introductions could also affect the tele by changing molecular packing manner and distribution of FMO. Finally, according to our calculation, the 3d system is considered to be a promising electron transport material with small λele, high electron transport ability and good ambient stability.

  19. Theoretical investigations into the electronic structures and electron transport properties of fluorine and carbonyl end-functionalized quarterthiophenes.

    PubMed

    Li, Qian; Duan, Yuai; Gao, Hong-Ze; Su, Zhong-Мin; Geng, Yun

    2015-06-01

    In this work, we concentrate on systematic investigation on the fluorination and carbonylation effect on electron transport properties of thiophene-based materials with the aim of seeking and designing electron transport materials. Some relative factors, namely, frontier molecular orbital (FMO), vertical electron affinity (VEA), electron reorganization energy (λele), electron transfer integral (tele), electron drift mobility (μele) and band structures have been calculated and discussed based on density functional theory. The results show that the introduction of fluorine atoms and carbonyl group especially for the latter could effectively increase EA and reduce λele, which is beneficial to the improvement of electron transport performance. Furthermore, these introductions could also affect the tele by changing molecular packing manner and distribution of FMO. Finally, according to our calculation, the 3d system is considered to be a promising electron transport material with small λele, high electron transport ability and good ambient stability. PMID:25909689

  20. Distribution of macroalgae and sediment chlorophyll A along salinity and elevation gradients in Oregon tidal marshes

    EPA Science Inventory

    Algae contribute to trophic and biogeochemical processes in tidal wetlands. We investigated patterns of sediment pigment content and macroalgal abundance and diversity in marshes in four Oregon estuaries representing a variety of vegetation types, salinity regimes, and tidal ele...

  1. Effects of Eucommia leaf extracts on autonomic nerves, body temperature, lipolysis, food intake, and body weight.

    PubMed

    Horii, Yuko; Tanida, Mamoru; Shen, Jiao; Hirata, Tetsuya; Kawamura, Naomi; Wada, Atsunori; Nagai, Katsuya

    2010-08-01

    Eucommia ulmoides Oliver leaf extracts (ELE) have been shown to exert a hypolipidemic effect in hamsters. Therefore, it was hypothesized that ELE might affect lipid metabolism via changes in autonomic nerve activities and causes changes in thermogenesis and body weight. We examined this hypothesis, and found that intraduodenal (ID) injection of ELE elevated epididymal white adipose tissue sympathetic nerve activity (WAT-SNA) and interscapular brown adipose tissue sympathetic nerve activity (BAT-SNA) in urethane-anesthetized rats and elevated the plasma concentration of free fatty acids (FFA) (a marker of lipolysis) and body temperature (BT) (a marker of thermogenesis) in conscious rats. Furthermore, it was observed that ID administration of ELE decreased gastric vagal nerve activity (GVNA) in urethane-anesthetized rats, and that ELE given as food reduced food intake, body and abdominal adipose tissue weights and decreased plasma triglyceride level. These findings suggest that ELE stimulates lipolysis and thermogenesis through elevations in WAT-SNA and BAT-SNA, respectively, suppresses appetite by inhibiting the activities of the parasympathetic nerves innervating the gastrointestinal tract, including GVNA, and decreases the amount of abdominal fat and body weight via these changes.

  2. Inhibitory effects of eucalyptus and banaba leaf extracts on nonalcoholic steatohepatitis induced by a high-fructose/high-glucose diet in rats.

    PubMed

    Takahashi, Yoshihisa; Sugimoto, Keiichiro; Soejima, Yurie; Kumagai, Arisa; Koeda, Tatsuki; Shojo, Aiko; Nakagawa, Kazuya; Harada, Naoki; Yamaji, Ryoichi; Inui, Hiroshi; Yamanouchi, Toshikazu; Fukusato, Toshio

    2015-01-01

    Nonalcoholic steatohepatitis (NASH) is a liver disease associated with metabolic syndrome. The aim of this work was to examine whether eucalyptus (Eucalyptus globulus) leaf extract (ELE) and banaba (Lagerstroemia speciosa L.) leaf extract (BLE) inhibited NASH induced by excessive ingestion of fructose in rats. Wistar rats were divided into four groups according to four distinct diets: starch diet (ST), high-fructose/high-glucose diet (FG), FG diet supplemented with ELE, or FG diet supplemented with BLE. All rats were killed after 5 weeks of treatment. Serum alanine aminotransferase and total cholesterol levels were significantly lower in the BLE group than in the FG group. Liver histopathology, including steatosis, lipogranulomas, and perisinusoidal fibrosis, was significantly attenuated in the ELE and BLE groups compared with the FG group. Levels of 2-thiobarbituric acid reactive substances (TBARS), which reflect oxidative injury to the liver, were significantly suppressed by ELE and BLE. Western blotting analysis indicated that interleukin-6 expression levels were significantly lower in the ELE and BLE groups than in the FG group. These results suggest that ELE and BLE reduced lipogenesis, oxidative stress, and inflammatory cytokine expression and thus inhibited NASH induced by excessive ingestion of fructose in rats.

  3. The Role of the Federal Government in Financing Health and Medical Services

    ERIC Educational Resources Information Center

    Bloom, Bernard S.; Martin, Samuel

    1976-01-01

    This analysis of public and private sector spending for health services shows they have paralleled each other for four decades although total expenditures have grown dramatically. Since 1966 the federal government's major participation has been through the Medicare trust fund. Need for larger government role is predicted. (Editor/JT)

  4. Assessing Competence in Pediatric Cardiology

    ERIC Educational Resources Information Center

    Johnson, Apul E.; And Others

    1976-01-01

    In response to the need to assure physician competence, a rating scale was developed at the University of Minnesota Medical School for use in evaluating clinical competence in pediatric cardiology. It was tested on first- and second-year specialists. Development and testing procedures are described. (JT)

  5. Screening, Deschooling and Developing Countries

    ERIC Educational Resources Information Center

    Hinchliffe, Keith

    1975-01-01

    Examines the present debate surrounding deschooling (abolition or non-setting up of schools) particularly hypotheses regarding the use of schooling as a screening device for occupational selection. Analyzes its relevance for low-income, low-schooling countries in light of recent data from Northern Nigeria on education and labor productivity. (JT)

  6. National Education Trust Fund

    ERIC Educational Resources Information Center

    Shapp, Milton J.

    1975-01-01

    A proposal from the governor of Pennsylvania for financing all levels of education through a National Education Trust Fund (NETF) that would operate as the present Federal Highway Trust Fund does on a revolving, self-liquidating basis with the cost of an individual's education repaid through a progressive education tax on income. (JT)

  7. The Future of Diversity in a Time of Retrenchment

    ERIC Educational Resources Information Center

    Riesman, David

    1975-01-01

    Less obvious reasons for the decline of private educational institutions are discussed and suggestions made as to what type is most durable. The author supports the idea of an Educational Opportunity Bank to provide student loans and analyzes it with respect to maintenance of diversity, quality, and student choice. (Editor/JT)

  8. Educational Materials Reviewed for AVLINE

    ERIC Educational Resources Information Center

    Jones, Norbert A.; And Others

    1976-01-01

    Information gathered from faculty members about nontextbook educational materials is reviewed by the Association of American Medical Colleges before cataloging, indexing, and abstracting at the National Library of Medicine for listing in AVLINE, a computer information service available through the MEDLARS system. (JT)

  9. Scientific Research and Agricultural Innovation in Israel

    ERIC Educational Resources Information Center

    Ben-David, Joseph; Katz, Shaul

    1975-01-01

    Traces the development and interrelationships of agriculture and agricultural research in Israel since 1920, concluding that major contributing factors to successful relationship between research and production in agriculture are a rise in the educational level of the agricultural population and a thorough knowledge of the soil and climate. (JT)

  10. Is The Modern Lease a Contract or a Conveyance?--A Historical Inquiry

    ERIC Educational Resources Information Center

    Siegel, Stephen A.

    1975-01-01

    Argues that "contrary to conventional wisdom, current landlord-tenant law is modern, commercial, and already grounded in contract doctrine." Discusses the origins of the doctrines most frequently cited as illustrations of leasings property basis and redevelops the role of property law in adjudicating leasing disputes. (JT)

  11. The French Lesson: The Right to Culture

    ERIC Educational Resources Information Center

    Gagnon, Paul

    1975-01-01

    Noting that "career education is only the latest in the grand parade of American learning fads," the author points out that despite the proliferation of technology in France and the habit of accepting American fads, the French still consider education to have three aims--for work, for public life, for private life. (JT)

  12. Collective Bargaining Rejected: Two Case Histories

    ERIC Educational Resources Information Center

    Lozier, G. Gregory; Lussier, Virginia Lee

    1975-01-01

    The findings of two case studies of "no agent" victories in faculty representation elections are reported: Albion College, a small, private, co-educational, church-related college, and Michigan State University, a multi-missioned public university, first member of the Big Ten to have faculty representation elections. (JT)

  13. Extended region of nodulation genes in Rhizobium meliloti 1021. I. Phenotypes of Tn5 insertion mutants

    SciTech Connect

    Swanson, J.A.; Tu, J.K.; Ogawa, J.; Sanga, R.; Fisher, R.F.; Long, S.R.

    1987-10-01

    Rhizobium meliloti Nod/sup -/ mutant WL131, a derivative of wild-type strain 102F51, was complemented by a clone bank of wild-type R. meliloti 1021 DNA, and clone pRmJT5 was recovered. Transfer of pRmJT5 conferred alfalfa nodulation on other Rhizobium species, indicating a role in host range determination for pRmJT5. Mutagenesis of pRmJT5 revealed several segments in which transposon insertion causes delay in nodulation, and/or marked reduction of the number of nodules formed on host alfalfa plants. The set of mutants indicated five regions in which nod genes are located; one mutant, nod-216, is located in a region not previously reported to encode a nodulation gene. Other mutant phenotypes correlated with the positions of open reading frames for nodH, nodF and nodE, and with a 2.2-kb EcoRI fragment. A mutant in nodG had no altered phenotype in this strain. One nodulation mutant was shown to be a large deletion of the common nod gene region. The authors present a discussion comparing the various studies made on this extended nod gene region.

  14. A Seminar in Legal Aspects of Minority Economic Development

    ERIC Educational Resources Information Center

    Donegan, Charles Edward

    1975-01-01

    The 2-hour elective seminar described here was designed to prepare second- and third-year law students to perform the role of legal counselor to potential and existing minority businessmen in forming or expanding business enterprises. Seminar outline and notes on materials, reading, research assignments, and resource persons are included. (JT)

  15. An Instrument for the Identification of Core Curriculum in the Discipline of Gynaecology

    ERIC Educational Resources Information Center

    Taylor, P. J.

    1976-01-01

    Describes an instrument designed to identify with considerable agreement appropriate knowledge, skills, and attitudes for gynecology curriculum, relate it to other curriculum content, and determine where it should appear in the curriculum. Focus is on clinical problems to be solved and the underlying processes. (JT)

  16. Dental Topics for Medical Students

    ERIC Educational Resources Information Center

    Lorber, Mortimer

    1976-01-01

    As part of the required Introduction to Clinical Sciences course, second-year students at Georgetown University School of Medicine attend three one-hour lectures on dentistry: restorative dentistry, oral surgery, and various diseases. Contents of the lectures are summarized here. (JT)

  17. Teaching Geology on Weekends and at Shopping Centers.

    ERIC Educational Resources Information Center

    Mirsky, Arthur; East, James R.

    1981-01-01

    The success of an outreach education program held by Indiana University-Purdue University at Indianapolis is described. The college offers regular credit courses on Saturday and Sunday for people who could not take regularly scheduled courses. A Learn and Shop program held at shopping centers is also described. (JT)

  18. Understanding Alcoholism: A Test for Use in Medical Education

    ERIC Educational Resources Information Center

    Weinberg, Jon R.; Morse, Robert

    1975-01-01

    Describes a test, entitled Understanding Alcoholism, intended to serve as an educational or measurement instrument (or both) for use in the training of physicians. The test directly exposes many controversial aspects of alcoholism to the student at a time when his attitudes toward this disorder are being shaped. (Authors/JT)

  19. A Profile of Clinical Nutrition Knowledge Among Physicians and Medical Students

    ERIC Educational Resources Information Center

    Podell, Richard N.; And Others

    1975-01-01

    An assessment of the clinical nutritional knowledge of third- and fourth-year medical students and practicing physicians revealed that overall nutritional knowledge is modest and that knowledge is highest among topics which have received the most publicity in the popular press. Methodology and specific findings are included. (JT)

  20. Alexander v. Gardner-Denver: A Threat to Title VII Rights

    ERIC Educational Resources Information Center

    Richards, Richard F.

    1975-01-01

    An examination of the decision on the rights of an employee, who has unsuccessfully pursued a race or sex discrimination claim through arbitration, to "relitigate" the claim under Title VII, Civil Rights Act of 1964. Conclusion: the decision endangers Title VII rights by granting too much weight to prior arbitration awards. (JT)

  1. Current Developments in Federal Law Affecting Equal Employment Opportunity in Higher Education

    ERIC Educational Resources Information Center

    Frohnmayer, David B.

    1973-01-01

    Reviews issues and administrative regulations pertaining to affirmative action under Executive Orders 11246 and 11375, extension of Title VII of the Civil Rights Act of 1964 to academic and professional employment, and the Higher Education Ammendments of 1972 extending provisions of the Equal Pay Act of 1963. (JT)

  2. The Back Pay Remedy in Title VII Class Actions: Problems of Procedure

    ERIC Educational Resources Information Center

    Edwards, Charles A.

    1974-01-01

    The class action for back pay has developed as a significant factor in employment discrimination litigation under Title VII of the Civil Rights Act of 1964. Problems of demonstrating each class member's entitlement are examined and a bifurcated trial procedure is proposed as a method for handling such cases. (JT)

  3. The Inevitable Interplay of Title VII and the National Labor Relations Act: A New Role for the NLRB

    ERIC Educational Resources Information Center

    University of Pennsylvania Law Review, 1974

    1974-01-01

    The impact of Title VII of the Civil Rights Act of 1964 on seniority and the treatment of employment discrimination under the National Labor Relations Act of 1935 are examined. It is argued that in the area of seniority the National Labor Relations Board (NLRB) has a new role to play in avoiding conflicts between the two acts. (JT)

  4. Operational Management of Area Environment.

    ERIC Educational Resources Information Center

    Sprague, George W.

    Three phases leading to the automation of the mechanical building systems on the Harvard campus are described. The systems allow a single operator to monitor and control all the mechanical systems, plus fire, flood, and security alarms, for all buildings in a large area of the campus. (JT)

  5. Equal Employment + Equal Pay = Multiple Problems for Colleges and Universities

    ERIC Educational Resources Information Center

    Steinbach, Sheldon Elliot; Reback, Joyce E.

    1974-01-01

    Issues involved in government regulation of university employment practices are discussed: confidentiality of records, pregnancy as a disability, alleged discrimination in benefits, tests and other employment criteria, seniority and layoff, reverse discrimination, use of statistics for determination of discrimination, and the Equal Pay Act. (JT)

  6. Admissions and Preferences: Sequel to Defunis

    ERIC Educational Resources Information Center

    Wilson, James B.

    1973-01-01

    Three unresolved affirmative action admissions problems are examined: the role of students in admissions decisions, the validity of racial quotas, and to what extent applicants are entitled to due process protection of the fourteenth ammendment. Included is a synopsis of DeFunis v. Odegaard, which upheld a reverse discrimination claim. (JT)

  7. Beating the Bureaucrats

    ERIC Educational Resources Information Center

    Saunders, Charles B., Jr.

    1976-01-01

    In dealing with government red tape, the author suggests, five rules can help: Don't believe politicians' promises of "deregulation"; Don't accept any regulation as final; Do your homework; Give your expertise, even if nobody asks for it; and Maintain standards of professional conduct and competence. (Editor/JT)

  8. Integrating Content on Feminism and Racism into the Social Work Curriculum

    ERIC Educational Resources Information Center

    Loewenstein, Sophie F.

    1976-01-01

    It is suggested that power relationships among people have become a unifying concept of human behavior in modern society, replacing the Freudian libido, and that this concept can function as a unifying principle for integrating racism, sexism and other key relationship concerns into the human behavior curriculum sequence. (Editor/JT)

  9. Sequence-characterized amplified polymorphism markers for selecting rind stripe pattern in watermelon (Citrullus lanatus var. lanatus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inheritance of foreground stripe pattern in rind of watermelon fruits [Citrullus lanatus (Thunb.) Matsum. & Nakai] was evaluated and the molecular markers for selecting the JT stripe pattern were developed based on bulked segregant analysis (BSA). Divergence in rind pattern among F2 progeny deri...

  10. The Coagulation Method of Starting Lecture-Discussion Courses

    ERIC Educational Resources Information Center

    Nyberg, David

    1976-01-01

    Describes a method used in the first class periods of a foundations of education course of 20-35 students to introduce students to each other and develop the interpersonal climate necessary for an effective discussion course. Involves breaking up into groups of five strangers for personal introductions and later class presentations. (JT)

  11. Policy-Making in a Negotiating Society

    ERIC Educational Resources Information Center

    Carey, William D.

    1976-01-01

    A national disenchantment with knowledge, which sets up a contest between reason and mindlessness, and a strong tilt in the direction of conservative fiscal policy are cited as cause for those seeking support for science to take the initiative and negotiate a workable policy future. (JT)

  12. Applying Empirical and Computer Technique in Teaching Undergraduate Sociology

    ERIC Educational Resources Information Center

    O'Kane, James M.

    1976-01-01

    A 2-semester undergraduate sociology course in empirical techniques and computer analysis is described which permits the student maximum freedom in his choice of a research problem while encouraging him to use both a statistical design and a computer analysis to test his hypotheses. (JT)

  13. Unfair Labor Practices in the Academic Setting

    ERIC Educational Resources Information Center

    Holway, Loretta W.; O'Donnell, Thomas L. P.

    1974-01-01

    The scope of individual employee rights to engage in activities under the National Labor Relations Act and the concomitant restrictions on employer actions, as interpreted in decisions of the National Labor Relations Board and the courts, are examined on the premise that college administrators are well-advised to understand them. (JT)

  14. Cluster of Infections Caused by Methicillin-Resistant Staphylococcus pseudintermedius in Humans in a Tertiary Hospital

    PubMed Central

    Börjesson, Stefan; Grönlund-Andersson, Ulrika; Tellgren-Roth, Christian; Melhus, Åsa

    2014-01-01

    The dog-associated Staphylococcus pseudintermedius is a rare pathogen in humans. Here we describe a cluster of infections caused by the methicillin-resistant S. pseudintermedius clone ST71-J-t02-II–III. It involved four elderly patients at a tertiary hospital. Three patients had wound infections, and the strain had a tendency to cause bullous skin lesions. PMID:24871217

  15. Characteristics of a liquid-helium-free calibration apparatus for cryogenic thermometers

    SciTech Connect

    Shimazaki, T.

    2013-09-11

    Closed-cycle Joule-Thomson (JT) cryocoolers have been developed at National Metrology Institute of Japan (NMIJ)/National Institute of Advanced Industrial Science and Technology (AIST) with the aim of realizing a liquid-helium-free calibration apparatus for cryogenic thermometers between 0.65 K and 25 K. The latest JT cryocooler at NMIJ/AIST consists of a {sup 3}He JT cooling circuit and a pulse tube mechanical refrigerator. The characteristics of the apparatus including a residual gas analysis of the JT cooling circuit are presented in this paper. Currently the initial cool-down is performed using a heat-exchange gas. It normally takes about 30 h to reduce the temperature from room temperature to 5 K at the thermometer comparison block of the apparatus. The correct timing of the removal of the heatexchange gas is important for the efficient operation of the apparatus. Incomplete removal of the heat-exchange gas induces excess heat load on the apparatus and thermal disturbances. Some examples of abrupt temperature bursts are discussed in this paper. Mechanical refrigerators generate cyclic mechanical vibrations, and precision resistance thermometers are usually very sensitive to a mechanical vibration. The measured vibration level of the developed apparatus is reported. The damage to the apparatus due to the magnitude 9.0 earthquake on March 11, 2011, and possible countermeasures in the case of future earthquakes are also discussed.

  16. The Scientific Prototype, a Proposed Next Step for the American MFE Program

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2013-08-01

    The "Scientific Prototype" is a tokamak about the size and power of JET, TFTR or JT-60, but which runs steady state in DT and breeds its own tritium. This paper, more in the spirit of an editorial than a scientific research publication, argues that it is the only reasonable option for the American MFE program.

  17. Educational Opportunities in "Law and Medicine" in Law Schools

    ERIC Educational Resources Information Center

    Hirsh, Harold L.

    1975-01-01

    Noting the rapid expansion of forensic or legal medicine the author reports a survey conducted to determine the medical-legal education opportunities in American law schools. Findings showed that in 73 percent of the schools courses in law and medicine or forensic psychiatry are offered but many are limited in scope. (JT)

  18. Pseudorotation in fullerene anions

    NASA Astrophysics Data System (ADS)

    Dunn, Janette L.; Hands, Ian D.; Bates, Colin A.

    2007-07-01

    Jahn-Teller (JT) problems are often characterised by an adiabatic potential energy surface (APES) containing either a set of isoenergetic wells or a trough of equivalent-energy points, which may be warped by higher-order coupling terms or anisotropic effects. In all three cases, the JT effect will be dynamic. Either tunnelling between the wells or rotation (of a distortion) around the trough will restore the original symmetry of the system. This motion is referred to as pseudorotation. It should be possible to observe a JT system in a distorted geometry if measurements are made on a sufficiently short timescale. In various cubic systems, this timescale has been calculated to be the order of picoseconds. Such timescales are accessible using modern methods of ultrafast spectroscopy. Measurements of pseudorotation rates can lead to important information on the strength and nature of the JT coupling present. We will present analytical calculations that allow the rate of pseudorotation to be determined in terms of the vibronic coupling parameters. We will show how these results can be applied to E ⊗ e systems and then to the more complicated system applicable to C60- anions. This is of particular interest because of the high icosahedral symmetry of fullerene ions and also because of the many potential uses of materials containing these ions. We conclude by outlining experiments that should be capable of measuring pseudorotation in C 60 anions.

  19. Evaluation of Instructional Methods for Teaching Veterinary Students the Components of Inflammation

    ERIC Educational Resources Information Center

    Fletcher, O. J.; Welser, J. R.

    1975-01-01

    Seven multi-media instructional programs were evaluated on the basis of test scores, student attitudes, program preparation time, and cost of materials. Programs ranked best were videotape with 35mm slides, programmed instruction with 35mm slides, and Self-Evaluation Test only. (JT)

  20. Amending the Amendments

    ERIC Educational Resources Information Center

    McNamara, William

    1976-01-01

    Reviews activity in Congress, federal agencies, and higher education associations as legislation to extend and improve the 1972 Higher Education Amendments is being fashioned. Issues include a public vs. private debate regarding use of the Basic Opportunity Grant program (BOG) to foster access as opposed to choice among institutions. (JT)

  1. A Psychomotor Skills Course for Orthopaedic Residents

    ERIC Educational Resources Information Center

    Lippert, Frederick G.; And Others

    1975-01-01

    The course described and evaluated here was developed at the University of Washington School of Medicine to teach 20 orthopaedic residents operative techniques, instrument usage, and safety precautions outside of the operating room without hazard to the patient or regard to time constraints. (JT)

  2. Nyquist and Public Aid to Private Education

    ERIC Educational Resources Information Center

    Piekarski, Victor J.

    1975-01-01

    Noting that the latest Supreme Court decisions involving an application of the religion clauses of the first amendment to state statutes may serve to foreclose any further attempts by a state to aid parochial schools, the author suggests a new test that would satisfy both First Amendment and state aid proponent demands. (JT)

  3. A Couples Group of Medical Students

    ERIC Educational Resources Information Center

    Porter, Kenneth; And Others

    1976-01-01

    An experiment at the Albert Einstein College of Medicine with a short-term medical student couples' workshop designed to foster increased sensitivity between medical students and their partners resulted in recommendation that such workshops be offered to medical students. (JT)

  4. Academic Freedom in South Africa: The Open Universities in South Africa and Academic Freedom, 1957-1974

    ERIC Educational Resources Information Center

    Minerva, 1975

    1975-01-01

    When the South African government initiated a racial separation policy in universities in 1957 the Universities of Cape Town and Witwatersrand, Johannesburg, declared their opposition and continue after 17 years to pursue their efforts for racial equality. This report assesses the effects on university structure and academic freedom. (JT)

  5. Infrared Absorption Spectra of Jahn-Teller Systems: Application to the Transition-Metal Trifluorides MnF3 and NiF3.

    PubMed

    Mondal, Padmabati; Domcke, Wolfgang

    2014-05-14

    The theory for the calculation of vibronic absorption spectra within a Jahn-Teller (JT) active electronic state from first principles has been developed. The infrared absorption spectra of the (5)E' ground state, the low-lying (5)E″ excited state of MnF3, and the (4)E' state of NiF3 have been computed and analyzed. Dipole moment derivatives have been determined by a linear-plus-quadratic expansion of nuclear dipole moment functions in the JT-active coordinates. Electronic transition dipole moments have been taken into account in the Condon approximation in the diabatic representation. The initial and final vibronic states have been expanded in a product of diabatic electronic states and vibrational basis functions. The effect of spin-orbit coupling on the vibronic infrared spectra of these molecules in their JT-active electronic states has been investigated, by employing the Breit-Pauli spin-orbit operator. The effect of temperature on the vibronic infrared spectra has also been explored. These results represent the first theoretical study of vibronic infrared spectra of JT-active states in transition metal compounds.

  6. The Use of Test Results from ASA Workshops to Evaluate Workshop Effectiveness

    ERIC Educational Resources Information Center

    Donegan, Judith H.; And Others

    1976-01-01

    Results of test given to participants in six American Society of Anesthesiologists workshops were analyzed to determine whether attendance increased scores on sequential tests (before, immediately after, and three months later). Both workshop and control groups of anesthesiologists increased their scores with each successive test. (Editor/JT)

  7. Medical Anthropology in the Curriculum: A Revisit to the Subject

    ERIC Educational Resources Information Center

    Roush, Robert E.; And Others

    1976-01-01

    Although progress has been made in the last 15 years in the development of medical school departments with interests in the various behavioral science fields, including anthropology, based on this study only five percent of U.S. medical students had the opportunity to attend lectures in the field of medical anthropology. (Editor/JT)

  8. Instant Experience in Clinical Trials: A Computer-Aided Simulation Technique

    ERIC Educational Resources Information Center

    Simpson, Michael A.

    1976-01-01

    Describes "Instant Experience," a simulation and game method in which students are given information about a promising new drug and asked to design a protocol for a clinical trial of the drug. Evaluation of a trial workshop showed positive response to the method. Educational goals to be achieved through its use are noted. (JT)

  9. The Costs of "Openness"

    ERIC Educational Resources Information Center

    Cleveland, Harlan

    1975-01-01

    The author argues that very wide consultation tends to discourage innovation and favor stand-pattism and that the very great benefits of openness and wide participation are flawed by apathy and non-participation, by muscle-binding legalisms, by processes which polarize two adversary sides, and by the encouragement of mediocrity. (JT)

  10. Hoods for Science Laboratories.

    ERIC Educational Resources Information Center

    Horowitz, Harold; and others

    Detailed discussions are presented dealing with the selection and design of fume hoods for science laboratories. Areas covered include--(1) air flow design, (2) materials properties, (3) location in the laboratory, (4) testing and adjustment, (5) exhaust systems, and (6) hazards of fume discharges. (JT)

  11. Habits, Fears, and Desires of the Genus Graduate Student

    ERIC Educational Resources Information Center

    Taylor, Anne Robinson

    1976-01-01

    Based on interviews with graduate students in English, biochemistry, and psychology the author discusses common characteristics of graduate students (lifelong observers with faith in authority and strong emotional attachment to a minute field of inquiry) and notes implications for their teaching and their contributions to society. (JT)

  12. The Federal Role

    ERIC Educational Resources Information Center

    Davidson, Robert H.; Stark, Joan S.

    1976-01-01

    Traces emerging federal policy that constitutes a multidimensional attack on abuses of the educational consumer (involving Congress, the Office of Education, the Federal Trade Commission, Veterans Administration, Postal Service, and Bureau of Indian Affairs) aimed primarily at protecting federal investments. (Editor/JT)

  13. On the thermal gradient in the Earth's deep interior

    NASA Astrophysics Data System (ADS)

    Tirone, M.

    2016-02-01

    Temperature variations in large portions of the mantle are mainly controlled by the reversible and irreversible transformation of mechanical energy related to pressure and viscous forces into internal energy along with diffusion of heat and chemical reactions. The simplest approach to determine the temperature gradient is to assume that the dynamic process involved is adiabatic and reversible, which means that entropy remains constant in the system. However, heat conduction and viscous dissipation during dynamic processes effectively create entropy. The adiabatic and non-adiabatic temperature variation under the influence of a constant or varying gravitational field are discussed in this study from the perspective of the Joule-Thomson (JT) throttling system in relation to the transport equation for change of entropy. The JT model describes a dynamic irreversible process in which entropy in the system increases but enthalpy remains constant (at least in an equipotential gravitational field). A comparison is made between the thermal gradient from the JT model and the thermal gradient from two models, a mantle convection and a plume geodynamic model, coupled with thermodynamics including a complete description of the entropy variation. The results show that the difference is relatively small and suggests that thermal structure of the asthenospheric mantle can be well approximated by an isenthalpic model when the formulation includes the effect of the gravitational field. For non-dynamic or parameterized mantle dynamic studies, the JT formulation provides a better description of the thermal gradient than the classic isentropic formulation.

  14. Characteristics of a liquid-helium-free calibration apparatus for cryogenic thermometers

    NASA Astrophysics Data System (ADS)

    Shimazaki, T.

    2013-09-01

    Closed-cycle Joule-Thomson (JT) cryocoolers have been developed at National Metrology Institute of Japan (NMIJ)/National Institute of Advanced Industrial Science and Technology (AIST) with the aim of realizing a liquid-helium-free calibration apparatus for cryogenic thermometers between 0.65 K and 25 K. The latest JT cryocooler at NMIJ/AIST consists of a 3He JT cooling circuit and a pulse tube mechanical refrigerator. The characteristics of the apparatus including a residual gas analysis of the JT cooling circuit are presented in this paper. Currently the initial cool-down is performed using a heat-exchange gas. It normally takes about 30 h to reduce the temperature from room temperature to 5 K at the thermometer comparison block of the apparatus. The correct timing of the removal of the heatexchange gas is important for the efficient operation of the apparatus. Incomplete removal of the heat-exchange gas induces excess heat load on the apparatus and thermal disturbances. Some examples of abrupt temperature bursts are discussed in this paper. Mechanical refrigerators generate cyclic mechanical vibrations, and precision resistance thermometers are usually very sensitive to a mechanical vibration. The measured vibration level of the developed apparatus is reported. The damage to the apparatus due to the magnitude 9.0 earthquake on March 11, 2011, and possible countermeasures in the case of future earthquakes are also discussed.

  15. The Several Ages of Learning

    ERIC Educational Resources Information Center

    Bailey, Stephen

    1976-01-01

    Examines the various stages of human development (as outlined by Erik Erikson and others) with their psychological stresses of recurring crises of identity and expectation and explores some of the implications for education's best serving human needs. Focuses on early childhood, late adolescence, middle age, and old age. (JT)

  16. Preliminary design study of astronomical detector cooling system

    NASA Technical Reports Server (NTRS)

    Norman, R. H.

    1976-01-01

    The preliminary design of an astronomical detector cooling system for possible use in the NASA C-141 Airborne Infrared Observatory is presented. The system consists of the following elements: supercritical helium tank, Joule-Thomson supply gas conditioner, Joule-Thomson expander (JTX), optical cavity dewar, optical cavity temperature controller, adjustable J-T discharge gas pressure controller, and vacuum pump.

  17. The Terms and Tasks of "Open Admissions"

    ERIC Educational Resources Information Center

    Scott, Robert A.

    1976-01-01

    Noting the need to define the terms used for policies which are changing the role of admissions offices, the author defines "open admissions" as "universal opportunity for post-secondary schooling" and points out changes in the core tasks of recruiting, selecting, counseling, and management of student records and data. (JT)

  18. Bookstore in Trouble: The Proverbial Iceberg

    ERIC Educational Resources Information Center

    Sanderson, Ivan L.

    1975-01-01

    Examines the plight of two troubled bookstores, both state system stores with state charters as nonprofit corporations, probing some of their weaknesses, failures, and resultant difficulties and the positive action, including structural change and new management, involved in recovery and restoration of adequate operating funds. (JT)

  19. Ralf Dahrendorf's Vision for the London School of Economics

    ERIC Educational Resources Information Center

    Walker, David

    1976-01-01

    The goal of Ralf Dahrendorf, new director of the London School of Economics (LSE) is to restore the school's international reputation for the study of modern social science at both undergraduate and graduate levels with emphasis on the political role of social science knowledge. (JT)

  20. Columbia University Today: Why the Peanut Butter Revolution Didn't Spread

    ERIC Educational Resources Information Center

    Larned, Deborah

    1975-01-01

    A 1970 graduate of Columbia, who was involved in the 1968 student protests, returns to assess the mood of students and the Columbia Corporation (the University as a legal entity) and concludes that students are less militant, possibly because of admissions policies, but that the Columbia Corporation has not changed. (JT)

  1. Learning Under Siege on the West Bank

    ERIC Educational Resources Information Center

    Miller, Judith

    1975-01-01

    Birzeit College, the only secular institution of higher education in the Israeli-occupied territories, continues to operate with 500 Palestinians attending classes on the West Bank of the Jordan River Valley even though its president, expelled for alleged subversive activities, continues to run the college from Beirut. (JT)

  2. A "Careers in Medicine Seminar" for Secondary School Students

    ERIC Educational Resources Information Center

    Rodgers, Glen E.; And Others

    1976-01-01

    Describes a Thanksgiving weekend seminar for high school students sponsored for the last four years by Muskingum College. Information on careers and educational requirements were presented in lectures, panel and small group discussions, and direct informal contact with practicing professionals and medical educators. (JT)

  3. A Multidisciplinary Introduction to Community Medicine and Behavioral Science

    ERIC Educational Resources Information Center

    Turton, Frederick; Marine, William

    1975-01-01

    Emery School of Medicine's freshman behavioral science course, which includes units on medical care, psychiatry, and epidemiology, is directed toward attitude formation as well as intellectual development. Units and field experiences are described and evaluated and the course impact over a 4-year period found to be positive. (JT)

  4. Education for Becoming: Two Field Programs at Antioch

    ERIC Educational Resources Information Center

    Kelly, Michael; Prier, Linda

    1974-01-01

    Based on the premise that therapy is a way of learning, two Field Centers were developed: (1) a small group in New Mexico who studied geology, botany, wilderness survival skills and themselves, the latter using group dream study methods and (2) a group in Switzerland to study Jungian psychology including individual analysis. (JT)

  5. 1974-1975 Annual Survey of Labor Relations and Employment Discrimination Law

    ERIC Educational Resources Information Center

    Lombardi, Robert Philip; And Others

    1975-01-01

    Major headings in this review of 1974-75 labor relations and employment discrimination law include Unfair Labor Practices, Arbitration, Seniority, Sex Discrimination, Affirmative Action Under Title VII, Equal Employment Opportunity Commission Enforcement Powers under Section 706, and Federal Employment--Judicial Application of Section 717. (JT)

  6. Genetic defects associated with familial and sporadic hyperparathyroidism.

    PubMed

    Hendy, Geoffrey N; Cole, David E C

    2013-01-01

    Primary hyperparathyroidism (PHPT) occurs sporadically, but occasionally it may be a feature of a familial condition, such as multiple endocrine neoplasia type 1 (MEN1), MEN2A, or the HPT-jaw tumor syndrome (HPT-JT), and familial hypocalciuric hypercalcemia/neonatal severe hyperparathyroidism (FHH/NSHPT). PHPT may also occur as familial isolated hyperparathyroidism (FIHP), and has been observed as a consequence of mutations in the CDKN1B gene (MEN4). Tumorigenesis in these conditions may be the result of protooncogene activation (e.g. RET in MEN2) or two-hit losses of a tumor suppressor (e.g. MEN1, HPT-JT). In patients with MEN1, HPT-JT or FHH/NSHPT, the hyperparathyroidism manifests at a younger age and affects both sexes equally. In MEN1, mutations of the MEN1 gene also cause enteropancreatic and anterior pituitary tumors. In MEN2, activating mutations in the RET protooncogene also cause medullary thyroid carcinoma and pheochromocytoma. In HPT-JT, mutations of CDC73/HRPT2 are associated with parathyroid carcinoma, but tumors of the kidneys and uterus are additional features. In some FIHP families, a CASR mutation may be identified. In parathyroid carcinoma, even if sporadic, molecular diagnostics for CDC73/HRPT2 should be considered, as it should be for younger patients. Further exploration of these hereditary syndromes may shed light on the molecular mechanisms giving rise to nonhereditary PHPT. PMID:23652676

  7. The Management of Decline

    ERIC Educational Resources Information Center

    Boulding, Kenneth E.

    1975-01-01

    With the probability of declining enrollments education needs, according to the author, to develop administrators skilled in adjusting to decline. He notes what educators can learn from the decline of agriculture and railroads and points up the need to get out from under the grants economy. (JT)

  8. A Marketing Plan That Works

    ERIC Educational Resources Information Center

    Sparks, Jack D.

    1976-01-01

    Olivet College's marketing plan included survey of students, alumni, townspeople, and doners and analysis of the college's customer appeal, prices, and product mix. The author reports that the marketing objectives are being met and discusses the rationale and problems of applying business marketing principles to education. (JT)

  9. DeFunis v. Odegaard: The "Non-Decision" with a Message

    ERIC Educational Resources Information Center

    Lavinsky, Larry M.

    1975-01-01

    Based on the question of whether racial preference and quotas to advance the educational opportunities of certain racial and ethnic minorities are compatible with the equal protection clause of the Fourteenth Amendment, a case against reference to race is presented in light of the DeFunis v. Odegaard case. (JT)

  10. A Critical Review of the West African School Certificate Examination Syllabus in History as Taught in Western Nigeria Grammar Schools

    ERIC Educational Resources Information Center

    Adejunmobi, S. A.

    1974-01-01

    The author compares syllabus outlines for the 5-year grammar school course (Grades 8-12 equivalent) in West Africa, Nigeria, the United Kingdom, and the United States, and concludes that a national directive on history syllabus similar to that of Britain and the U.S. is needed including aims of history teaching in Nigeria. (JT)

  11. Microchannel heat exchanger for two-phase Mixed Refrigerant Joule Thomson process

    NASA Astrophysics Data System (ADS)

    Baek, Seungwhan; Lee, Jisung; Lee, Cheonkyu; Jeong, Sangkwon

    2014-01-01

    Mixed Refrigerant Joule Thomson (MR-JT) refrigerators are widely used in various kinds of cryogenic systems these days. Printed Circuit Heat Exchanger (PCHE) is one of the promising cryogenic compact recuperators for MR-JT refrigerators due to its compactness, high NTU and robustness. However, PCHE composed with microchannel bundles can cause flow mal-distribution, and it can cause the degradation of thermal performance of the system. To mitigate the flow mal-distribution problem, the cross link (or intra-layer bypass) can be adapted to parallel microchannels. Two heat exchangers are fabricated in this study; one has straight channels, and the other one has intra-layer bypass structure between channels to enhance the flow distribution. The MR-JT refrigerators are operated with these two heat exchanger and the no-load temperatures are compared. The lower no load temperature achieved with the intra-layer bypass structured heat exchanger. The results indicate that the flow mal-distribution in the microchannel heat exchanger can be mitigated with intra-layer bypass structure, and relaxation of flow mal-distribution in the heat exchanger guarantee the MR-JT refrigerator's performance.

  12. Primary Care, Ambulatory Care, and Family Medicine: Overlapping But Not Synonymous

    ERIC Educational Resources Information Center

    Reynolds, Robert E.

    1975-01-01

    Defines and depicts graphically the relationships between primary, secondary, and tertiary care functions (from least to most intensified phases of medical care); ambulatory care (care of sick or well people not confined to bed); and family medicine (an emerging medical discipline focusing on complete and longterm care of the family). (JT)

  13. Letter From the Barricades: What Price CUNY?

    ERIC Educational Resources Information Center

    Katz, Jeffrey M.

    1976-01-01

    A student at Lehman College describes student reaction to the threat of loss of free tuition and open admissions at New York City University. To money managers, he contends, they represent a "noble tradition," to students economic necessities. (Editor/JT)

  14. Visual investigation of solid-liquid phase equilibria for nonflammable mixed refrigerant

    NASA Astrophysics Data System (ADS)

    Lee, C.; Yoo, J.; Park, I.; Park, J.; Cha, J.; Jeong, S.

    2015-12-01

    Non-flammable mixed refrigerant (NF-MR) Joule Thomson (J-T) refrigerators have desirable characteristics and wide cooling temperature range compared to those of pure J-T refrigerators. However, the operating challenge due to freezing is a critical issue to construct this refrigerator. In this paper, the solid-liquid phase equilibria (i.e. freezing point) of the NF-MR which is composed of Argon, R14 (CF4), and R218 (C3F8), has been experimentally investigated by a visualized apparatus. Argon, R14 and R218 mixtures are selected to be effectively capable of reaching 100 K in the MR J-T refrigerator system. Freezing points of the mixtures have been measured with the molar compositions from 0.1 to 0.8 for each component. Each test result is simultaneously acquired by a camcorder for visual inspection and temperature measurement during a warming process. Experimental results show that the certain mole fraction of Argon, R14, and R218 mixture can achieve remarkably low freezing temperature even below 77 K. This unusual freezing point depression characteristic of the MR can be a useful information for designing a cryogenic MR J-T refrigerator to reach further down to 77 K.

  15. Time Management in Higher Education Administration: A Case Study

    ERIC Educational Resources Information Center

    Lewis, Darrell R.; Dahl, Tor

    1976-01-01

    Drawing on data from a staff development project for administrators in a college at a major American university, it was determined that there is considerable commonality across individuals and that it is possible to deal with such issues as time management, job stress, and enjoyment on an organizational level. (Editor/JT)

  16. The Importance of Comparative Law in Legal Education: United States Goals and Methods of Legal Comparison

    ERIC Educational Resources Information Center

    Ault, Hugh J.; Glendon, Mary Ann

    1976-01-01

    Discusses the rationale for teaching comparative law and describes techniques and results of experiments with two kinds of courses at Boston College Law School: (1) Comparative Legal Analysis, a perspective course, and (2) integration of comparative law as another dimension into courses in a particular subject matter area. (JT)

  17. Teachers and the First Amendment: Academic Freedom and Exhaustion of Administrative Remedies under 42 U.S.C. Section 1983

    ERIC Educational Resources Information Center

    Moskowitz, Ivor R.; Casagrande, Richard E.

    1975-01-01

    The difficulties of defining academic freedom are noted in an exploration of recent judicial attempts to define the scope of teachers' First Amendment rights in the area of intramural speech. The exhaustion of administrative remedies in cases brought under 42 U.S.C. section 1983 (a basic statute in such cases) is also discussed. (JT)

  18. 75 FR 6849 - Airworthiness Directives; Airbus Model A310-221, -222, -322, -324, and -325 Airplanes, and Model...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-12

    ... July 16, 2009 (74 FR 34516). That NPRM proposed to correct an unsafe condition for the specified... Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant economic impact, positive or... Airplanes, Equipped With Pratt & Whitney PW4000 or JT9D-7R4 Series Engines AGENCY: Federal...

  19. China's Succession Battle Stirs Higher Education Debate

    ERIC Educational Resources Information Center

    Cleverley, John

    1976-01-01

    Describes the current debate going on in Chinese political and educational circles regarding the quality of university education since the Cultural Revolution. Those being singled out for their bourgeois line are critical of such practices as nonacademic selection criteria and the weight given to practical experience in the shortened courses. (JT)

  20. An Alternative to Anesthetic Learning Climates

    ERIC Educational Resources Information Center

    Epperson, David C.

    1975-01-01

    On the premise that the college classroom should heighten, not cool, a zeal for learning, the author proposes that colleges extend the range of alternative paths to personal growth through a program of voluntary temporary learning communities using diverse modes of inquiry. (JT)

  1. Mandatory Housing Requirements: The Constitutionality of Parietal Rules

    ERIC Educational Resources Information Center

    Iowa Law Review, 1975

    1975-01-01

    Analyzes the validity of parietal rules under both the due process and equal protection clauses of the Fourteenth Amendment. Models of substantive due process and equal protection are developed and applied to the various types of parietal rules that have been implemented at universities throughout the nation. (Author/JT)

  2. The Impact of Geduldig v. Aiello on the EEOC Guidelines on Sex Discrimination

    ERIC Educational Resources Information Center

    Bunnell, Rhoda

    1975-01-01

    From an analysis of criteria applicable to sex discrimination under the Fourteenth Amendment and the Civil Rights Act of 1964, Title VII, the author concludes that although the Fourteenth Amendment may not require standards such as those in the Equal Employment Opportunity Commission guidelines, neither does it prohibit them. (JT)

  3. Equal Protection of the Laws: Sex is Not a Suspect Classification; Kahn v. Shevin, 94 S. Ct. 1734 (1974)

    ERIC Educational Resources Information Center

    Thomas, Gregg Darrow

    1974-01-01

    In Kahn v. Shevin the Supreme Court upheld a Florida Supreme Court ruling that a state tax exemption for widows was not in violation of the Fourteenth Amendment. The author discusses this and earlier sex discrimination cases, holding that a strict scrutiny test in such cases would promote equality of the sexes. (JT)

  4. Photocopy of original drawing showing Wing A (drawing located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawing showing Wing A (drawing located at NAWS China Lake, Division of Public Works). J.T. STAFFORD-J.H. DAVIES-H.L. GOGERTY: DISPENSARY, SICK CALL AND ADMINISTRATION, ROOF FRAMING PLAN AND DETAILS - Naval Ordnance Test Station Inyokern, Dispensary, Main Site, Lauritsen Road at McIntyre Street, Ridgecrest, Kern County, CA

  5. Photocopy of original drawing showing Building 3 layout (drawing located ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawing showing Building 3 layout (drawing located at NAWS China Lake, Division of Public Works). J.T. STAFFORD-J.H. DAVIES-H.L. GOGERTY: DISPENSARY, CONNECTING CORRIDORS, FLOOR PLAN, ELEVATIONS, AND DETAILS - Naval Ordnance Test Station Inyokern, Dispensary, Main Site, Lauritsen Road at McIntyre Street, Ridgecrest, Kern County, CA

  6. Photocopy of original drawing showing Wing B (drawing located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawing showing Wing B (drawing located at NAWS China Lake, Division of Public Works). J.T. STAFFORD-J.H. DAVIES-H.L. GOGERTY: DISPENSARY, SURGICAL AND OBSTETRICAL, FLOOR PLAN AND ELEVATIONS - Naval Ordnance Test Station Inyokern, Dispensary, Main Site, Lauritsen Road at McIntyre Street, Ridgecrest, Kern County, CA

  7. Photocopy of original drawing showing Wing E (drawing located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawing showing Wing E (drawing located at NAWS China Lake, Division of Public Works). J.T. STAFFORD-J.H. DAVIES-H.L. GOGERTY: SICK OFFICERS QUARTERS, FLOOR PLAN AND ELEVATIONS - Naval Ordnance Test Station Inyokern, Dispensary, Main Site, Lauritsen Road at McIntyre Street, Ridgecrest, Kern County, CA

  8. Photocopy of original drawing showing Wing A (drawing located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original drawing showing Wing A (drawing located at NAWS China Lake, Division of Public Works). J.T. STAFFORD-J.H. DAVIES- H.L. GOGERTY: DISPENSARY, SICK CALL AND ADMINISTRATION, FLOOR PLAN AND ELEVATIONS - Naval Ordnance Test Station Inyokern, Dispensary, Main Site, Lauritsen Road at McIntyre Street, Ridgecrest, Kern County, CA

  9. Sex Discrimination as to Maternity Benefits

    ERIC Educational Resources Information Center

    Larson, Arthur

    1975-01-01

    A general survey of the state of the law at all points where maternity produces a claim of sex discrimination in employment and discussion of whether, under Geduldig v. Aiello, all private fringe benefit systems must equate normal pregnancy with temporary sickness and disability. (JT)

  10. Two-stage, low noise advanced technology fan. 5: Acoustic final report

    NASA Technical Reports Server (NTRS)

    Sofrin, T. G.; Riloff, N., Jr.

    1975-01-01

    The NASA Q2S(quiet two-stage) fan is a 0.836m (32.9 in.) diameter model of the STF 433 engine fan, selected in a 1972 study for an Advanced Technology Transport (ATT) airplane. Noise-control features include: low tip speed, moderate stage pressure rise, large blade-vane spacings, no inlet guide vanes, and optimum blade and vane numbers. Tests were run on the baseline Q2S fan with standard inlet and discharge ducts. Further tests were made of a translating centerbody sonic inlet device and treated discharge ducts. Results were scaled to JT8D and JT3D engine fan size for comparison with current two-stage fans, and were also scaled to STF 433 fan size to compare calculated ATT flyover noise with FAR 36 limits. Baseline Q2S results scaled to JT8D and JT3D engine fan sizes showed substantial noise reductions. Calculated unsuppressed baseline ATT flyovers averaged about 2.5 EPNdB below FAR 36 limits. Using measured sonic inlet results, scaled baseline Q2S fan results, and calculated attenuations for a 1975 technology duct liner, projected flyover noise calculations for the ATT averaged about FAR 36 limits minus 10 EPNdB. Advances in suppression technology required to meet the 1985 goal of FAR 36 limits minus 20 EPNdB are discussed.

  11. Higher Education and Human Resources: Communication Channels and Mechanisms of Coordination

    ERIC Educational Resources Information Center

    Wood, Lynn; Wilson, Robert C.

    1975-01-01

    Two models of the relationship between higher education and work are examined (market model and manpower planning model) in light of available data on student perceptions of education and careers, how they make career decisions, kinds of market information available to them and higher education personnel and how they use it. (JT)

  12. Handbook, Marlboro College, Vermont.

    ERIC Educational Resources Information Center

    Marlboro Coll., VT.

    Contents of this faculty handbook are academic and non-academic campus regulations, statements regarding the Privacy Act of 1974, an organizational chart, Marlboro College Community Constitution and By-Laws, Articles of Association of the Corporation of Marlboro College, and Alumni Association By-Laws. (JT)

  13. Poor Reception for Broadcast Graduates

    ERIC Educational Resources Information Center

    Carlisle, Robert D. B.

    1976-01-01

    Noting reports of 17,251 college juniors and seniors majoring in radio-television broadcasting and only 141,500 employees now working in the field, the author discusses the causes and implications including the value of the radio-TV degree and the cost of broadcast education. (JT)

  14. University Reform and Changes in Teaching in Chile

    ERIC Educational Resources Information Center

    Avalos, Beatrice

    1975-01-01

    Reports and discusses evaluation of a teaching techniques workshop for structural engineering lecturers designed to implement goals of Chilean university reform. Student and teacher course evaluations showed clear gains in student participation but not in the linking of teaching to national problems. (JT)

  15. Labor Law: The Equal Employment Opportunity Commission Is Not Limited to 180 Days From the Filing of a Charge in Which to Bring Suit Against an Employer. (EEOC v. Cleveland Mills Co., 502 F.2d 153 (4th Cir. 1974)

    ERIC Educational Resources Information Center

    Wharton, Larry

    1975-01-01

    Discusses the legality of Equal Employment Opportunity Commission (EEOC) action against Cleveland Mills Co. over four years after charges were filed with the EEOC in 1968. Concludes that the circuit court was right in reversing the district court decision that the EEOC has a time limit on its right to sue. (JT)

  16. 76 FR 72160 - Regulations and Procedures Technical Advisory Committee; Notice of Open Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ..., first serve basis. To join the conference, submit inquiries to Ms. Yvette Springer at Yvette.Springer... the meeting to Ms. Springer via email. For more information, call Yvette Springer at (202) 482-2813. Dated: November 16, 2011 Yvette Springer, Committee Liaison Officer. BILLING CODE 3510-JT-P...

  17. A Preliminary Examination of the In-Training Evaluation Report

    ERIC Educational Resources Information Center

    Skakun, Ernest N.; And Others

    1975-01-01

    The In-Training Evaluation Report (ITER), in use by the Royal College of Physicians and Surgeons of Canada for examining the competencies of candidates eligible for the certifying examination, was tested for validity and reliability. This analysis suggests revisions but declares the ITEA a useful instrument to aid in candidate assessment. (JT)

  18. In Search of Wisdom

    ERIC Educational Resources Information Center

    Vaccaro, Louis C.

    1975-01-01

    Arguing that students' demand for relevance is for wisdom rather than for utilitarian knowledge, and that it is caused by poor teaching, particularly in the liberal arts, the author emphasizes the individual teacher's responsibility to communicate the proper view of education, to lead students in their search for wisdom. (JT)

  19. 78 FR 73884 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Joint Task-Force...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ...''), Joint Task-Force Networked Media (``JT-NM'') has filed written notifications simultaneously with the...; Harman International, Stamford, CT; Janet West (individual member), Reading, United Kingdom, Nicole... to file additional written notifications disclosing all changes in membership. On July 10, 2013,...

  20. Remainder Gifts Under the Tax Reform Act of 1969: A Post-Final Regulation Outline, With Forms

    ERIC Educational Resources Information Center

    Myers, John Holt

    1973-01-01

    Reviews the Tax Reform Act of 1969 with regard to income, estate, or gift tax deductions available for the gift or bequest of a remainder interest. Compares the various types of deductible charitable remainder gifts. Legal forms are included for pooled income fund trusts and for charitable remainder annuity trust gifts and unitrust gifts. (JT)

  1. SHELTER THROUGH ARCHITECTURAL DESIGN, THE SHIELDING REQUIREMENTS INFLUENCE ON FORM.

    ERIC Educational Resources Information Center

    Office of Civil Defense (DOD), Washington, DC.

    FALLOUT PROTECTION CAN BE PROVIDED BY CAREFUL ARRANGEMENT OF ARCHITECTURAL ELEMENTS WITHOUT SPECIFIC FACILITIES FOR THEIR PURPOSE AND WITHOUT INTERFERING WITH NORMAL SPACE USE. CHARACTERISTICS OF RADIATION ARE DISCUSSED AND ILLUSTRATED PRINCIPLES OF SHIELDING DESIGN WITH RESPECT TO DISTANCE, GEOMETRY, AND TIME ARE GIVEN. (JT)

  2. Simulated Game Playing in Law School; An Experiment

    ERIC Educational Resources Information Center

    King, Donald B.

    1974-01-01

    Describes the successful use of six simulated games in a commercial law class of 84 students and discusses teacher and student evaluation of their effectiveness. The six games, three with a legislative setting and three with a court setting, are included. (JT)

  3. The Radcliffe Institute: Is There Life After Birth?

    ERIC Educational Resources Information Center

    Stent, Angela

    1975-01-01

    Purposes and program of the Radcliffe Institute are described from its creation in 1960 as "one effort to change the social climate for women" by offering part-time fellowships so that talented women might again become "visible professionally" to its present increasingly professional orientation. (JT)

  4. Optical and magnetic characterisation of Co3+ and Ni3+ in LaAlO3: interplay between the spin state and Jahn-Teller effect

    NASA Astrophysics Data System (ADS)

    Sanz-Ortiz, Marta N.; Rodríguez, Fernando; Rodríguez, Jesús; Demazeau, Gérard

    2011-10-01

    The coordination, the electronic structures and the spin of the ground state of Ni3+ (3d7) and Co3+ (3d6) introduced as impurities in LaAlO3 are investigated through optical spectroscopy and magnetic measurements. The unusual trivalent valence state in both transition-metal ions was stabilised via a sol-gel process followed by high oxygen pressure treatments. We show that the crystal-field strength at the nearly Oh transition-metal site in LaAlO3 locates Ni3+ and Co3+ near the spin state crossover, yielding a low-spin ground state in both cases. We analyse how the interplay between the Jahn-Teller (JT) effect and the spin state affects the magnetic moment of the ion and its temperature dependence. The optical spectra reveal a JT effect associated with a low-spin ground state in Ni3+ and with a thermally populated high-spin low-lying first excited state in Co3+. The corresponding JT distortions are derived from structural correlations. We conclude that the JT effect is unable to stabilise the intermediate spin state in Co3+. A low-spin ground state in thermal equilibrium with a high-spin low-lying first excited state is detected in diluted Co3+-doped LaAlO3. These results are compared with those obtained in the parent pure compounds LaNiO3 and LaCoO3.

  5. Interstitial Jurisprudence Illustrated in Teaching Criminal Law

    ERIC Educational Resources Information Center

    Funk, David A.

    1975-01-01

    The incorporation of criminal law theory into the first-year criminal law course is discussed as an example of adding the jurisprudence of specific subject matters to standard courses. Jurisprudential issues appropriate for study are suggested along with guidelines for teaching techniques, selection of materials, and use of class time. (JT)

  6. Cross-Year Comparison of Test-Retest MCAT Performance

    ERIC Educational Resources Information Center

    Land, Marcia S.; Feitz, Robert H.

    1976-01-01

    Scores were examined for students who repeated the Medical School Admissions Test (MCAT) within the same calendar year for years 1970-74. Nearly all repeaters showed improvement, low ability groups more and high ability students less. No pattern of greater MCAT improvement over time was found. (JT)

  7. Models: Caveats, Reflections, and Suggestions

    ERIC Educational Resources Information Center

    Kirschling, Wayne R.

    1976-01-01

    Noting that mathematical modeling is a relatively new phenomenon in higher education and that much can be learned from the misdirections and mistakes that characterize modeling in general, the author describes major criticisms of modeling and suggests improvements, particularly in communication between modelers and potential model users. (JT)

  8. The Reverend Thomas Jefferson Bowen: An Introductory Background to His Linguistic Works, 1850-1856

    ERIC Educational Resources Information Center

    Awoniyi, Timothy A.

    1974-01-01

    A historical narrative background for the linguistic works of Thomas Jefferson Bowen, an American missionary who was the first non-Nigerian to publish a grammar of Yoruba (1858). The author points up a need for further scholarly review of Bowen's pioneering work and contribution to Yoruba studies. (JT)

  9. Production of Artificial Lightning in An Ordinary Clear Light Bulb.

    ERIC Educational Resources Information Center

    Zaffo, Peter Alfred

    1981-01-01

    Reported is a method of producing artificial lightning in an ordinary clear lightbulb. The appearance of sparks produced is that of a miniature stroke of forked lightning seen in natural thunderstorms. The sparks also show the intricate branching patterns often seen in natural lightning. (JT)

  10. Effect of Jahn-Teller interactions on the specific heat and magnetic properties of charge-ordered La1-xCaxMnO3 (0.55⩽x⩽0.87) compounds

    NASA Astrophysics Data System (ADS)

    Qian, T.; Zheng, R. K.; Zhang, T.; Zhou, T. F.; Wu, W. B.; Li, X. G.

    2005-07-01

    The effect of Jahn-Teller (JT) interactions on specific heat and magnetic properties was studied for the series of La1-xCaxMnO3 (0.55⩽x⩽0.87) compounds by measurements of specific heat, ultrasonic velocity, and magnetization. Upon increasing x from 0.55 to 0.75, the enhancement of the JT interactions suppresses the ferromagnetic fluctuation above the charge ordering (CO) transition temperature TCO , increases the change of entropy associated with the charge/orbital ordering transition, and therefore enhances the stability of the CO state. With further increasing x from 0.75 to 0.87, the ferromagnetic fluctuation gradually swells up and the change of entropy almost linearly decreases, due to the reduction of the JT interactions. The magnetic field dependence of TCO was estimated based on the Clausius-Clapeyron equation, which well coincides with that obtained from the transport measurements in high magnetic fields. These results imply that the JT effect is a key ingredient in understanding the essential physics of the CO state.

  11. Antifungal properties of native Trichoderma isolates against Sclerotium rolfsii and Pythium aphanidermatum infecting tobacco.

    PubMed

    Rao, K L N Mallikharjuna; Raju, K Siva; Ravisankar, H

    2015-11-01

    Isolates of Trichoderma native to tobacco rhizosphere, were evaluated for their antifungal properties against Sclerotium rolfsii and Pythium aphanidermatum, fungal pathogens causing collar rot and damping off diseases in tobacco. Isolate TvJt1 showed maximum HCN production (0.14 OD) followed by ThHt1 and minimum by isolates ThJnt and ThRt1 (0.08 and 0.09 OD). Indole acetic acid (IAA) production among the isolates varied from 6.48 to 14.82 pg ml(-1). Isolate ThJO1 produced maximum siderophore (13.48 m mol ml(-1), whereas isolate TvJt1 produced minimum content (6.24 m mol ml(-1)). Isolate ThJt1 showed maximum and significantly higher chitinase activity (62.12 p kat m;(-1)) as compared to other isolates, followed by isolate TvHt2. Isolate TvHt2 showed maximum and significantly higher β-1, 3-glucanase activity (9.94 n kat ml(-1)) when compared to all other isolates. Isolate ThJt1 showed second highest activity of β-1, 3-glucanase (6.75 n kat/ml). In dual culture, inhibition of mycelial growth of Pythium by isolate TvHt2 was maximum (72.45%) followed by ThJt1 whereas inhibition of mycelial growth of S. rolfsii by these two isolates was at a par (78.36% and 76.17%) and significantly higher than some isolates. Isolates TvHt2 and ThJt1 showed maximum and significantly higher inhibition of Pythium and Sclerotium growth (80.24% and 76%) by production of non-volatiles. Inhibition of Pythium and Sclerotium growth by production of volatile compounds by Trichoderma isolates ranged from 54.36 to 72.6% and 66.24 to 84.24% respectively. Hence, further investigation with potential isolates ThJt1 and TvHt2 in tobacco nursery may help to explore these bioagents for control of collar rot and damping off diseases in tobacco. PMID:26688972

  12. Cultural conditions on the production of extracellular enzymes by Trichoderma isolates from tobacco rhizosphere.

    PubMed

    Mallikharjuna Rao, K L N; Siva Raju, K; Ravisankar, H

    2016-01-01

    Twelve isolates of Trichoderma spp. isolated from tobacco rhizosphere were evaluated for their ability to produce chitinase and β-1,3-glucanase extracellular hydrolytic enzymes. Isolates ThJt1 and TvHt2, out of 12 isolates, produced maximum activities of chitinase and β-1,3-glucanase, respectively. In vitro production of chitinase and β-1,3-glucanase by isolates ThJt1 and TvHt2 was tested under different cultural conditions. The enzyme activities were significantly influenced by acidic pH and the optimum temperature was 30°C. The chitin and cell walls of Sclerotium rolfsii, as carbon sources, supported the maximum and significantly higher chitinase activity by both isolates. The chitinase activity of isolate ThJt1 was suppressed significantly by fructose (80.28%), followed by glucose (77.42%), whereas the β-1,3-glucanase activity of ThJt1 and both enzymes of isolate TvHt2 were significantly suppressed by fructose, followed by sucrose. Ammonium nitrate as nitrogen source supported the maximum activity of chitinase in both isolates, whereas urea was a poor nitrogen source. Production of both enzymes by the isolates was significantly influenced by the cultural conditions. Thus, the isolates ThJt1 and TvHt2 showed higher levels of chitinase and β-1,3-glucanase activities and were capable of hydrolyzing the mycelium of S. rolfsii infecting tobacco. These organisms can be used therefore for assessment of their synergism in biomass production and biocontrol efficacy and for their field biocontrol ability against S. rolfsii and Pythium aphanidermatum infecting tobacco.

  13. Cultural conditions on the production of extracellular enzymes by Trichoderma isolates from tobacco rhizosphere

    PubMed Central

    Mallikharjuna Rao, K.L.N.; Siva Raju, K.; Ravisankar, H.

    2016-01-01

    Twelve isolates of Trichoderma spp. isolated from tobacco rhizosphere were evaluated for their ability to produce chitinase and β-1,3-glucanase extracellular hydrolytic enzymes. Isolates ThJt1 and TvHt2, out of 12 isolates, produced maximum activities of chitinase and β-1,3-glucanase, respectively. In vitro production of chitinase and β-1,3-glucanase by isolates ThJt1 and TvHt2 was tested under different cultural conditions. The enzyme activities were significantly influenced by acidic pH and the optimum temperature was 30 °C. The chitin and cell walls of Sclerotium rolfsii, as carbon sources, supported the maximum and significantly higher chitinase activity by both isolates. The chitinase activity of isolate ThJt1 was suppressed significantly by fructose (80.28%), followed by glucose (77.42%), whereas the β-1,3-glucanase activity of ThJt1 and both enzymes of isolate TvHt2 were significantly suppressed by fructose, followed by sucrose. Ammonium nitrate as nitrogen source supported the maximum activity of chitinase in both isolates, whereas urea was a poor nitrogen source. Production of both enzymes by the isolates was significantly influenced by the cultural conditions. Thus, the isolates ThJt1 and TvHt2 showed higher levels of chitinase and β-1,3-glucanase activities and were capable of hydrolyzing the mycelium of S. rolfsii infecting tobacco. These organisms can be used therefore for assessment of their synergism in biomass production and biocontrol efficacy and for their field biocontrol ability against S. rolfsii and Pythium aphanidermatum infecting tobacco. PMID:26887223

  14. Anatomo-histological analysis of the juncturae and their relations to the extensor tendons to the dorsum of the hand.

    PubMed

    Pinar, Yelda; Bilge, Okan; Govsa, Figen; Celik, Servet; Aktug, Huseyin

    2009-02-01

    The juncturae tendinum (JT) may coordinate the extension of hand, force redistribution and the stabilization of the metacarpophalangeal joint. The JT were studied for their gross appearance, shape, thickness, location and histological examination with the dorsum of the hand in 54 cadavers. The JT were identified into three groups according to their anatomo-histological features. The type 1 was observed in 57.4% of the cases in the second IMC and in 16.7% of the cases in the third IMC. The type 2 was detected in 3.7% of the cases in the second IMC and in 59.3% of the cases in the third IMC space. The type of 3Y was accounted for 14.8% JT in the third IMC space and 53.7% JT in the fourth space. The type of 3r was found in 5.55% of the cases in the third IMC and in 37% of the cases in the fourth IMC space. In the histologic examination, the fibers of types 1 and 2 JTs were straight. Type 3 JTs were composed of regularly oriented parallel and crosswise bundles of tendineous tissue. This study is important in terms of giving accurate knowledge on the anatomo-histological analysis of the JTs and their relations to the extensor tendons to the dorsum of the hand. An understanding of the structures of the JTs and the interactions between the tendons of the fingers is of utmost importance in hand assessment, during the reconstructive procedures such as considering the tendons to be transferred.

  15. Electrical stimulation to optimize cardioprotective exosomes from cardiac stem cells.

    PubMed

    Campbell, C R; Berman, A E; Weintraub, N L; Tang, Y L

    2016-03-01

    Injured or ischemic cardiac tissue has limited intrinsic capacity for regeneration. While stem cell transplantation is a promising approach to stimulating cardiac repair, its success in humans has thus far been limited. Harnessing the therapeutic benefits of stem cells requires a better understanding of their mechanisms of action and methods to optimize their function. Cardiac stem cells (CSC) represent a particularly effective cellular source for cardiac repair, and pre-conditioning CSC with electrical stimulation (EleS) was demonstrated to further enhance their function, although the mechanisms are unknown. Recent studies suggest that transplanted stem cells primarily exert their effects through communicating with endogenous tissues via the release of exosomes containing cardioprotective molecules such as miRNAs, which upon uptake by recipient cells may stimulate survival, proliferation, and angiogenesis. Exosomes are also effective therapeutic agents in isolation and may provide a feasible alternative to stem cell transplantation. We hypothesize that EleS enhances CSC-mediated cardiac repair through its beneficial effects on production of cardioprotective exosomes. Moreover, we hypothesize that the beneficial effects of biventricular pacing in patients with heart failure may in part result from EleS-induced preconditioning of endogenous CSC to promote cardiac repair. With future research, our hypothesis may provide applications to optimize stem cell therapy and augment current pacing protocols, which may significantly advance the treatment of patients with heart disease. PMID:26880625

  16. Decorated Shastry-Sutherland lattice in the spin-(1)/(2) magnet CdCu2(BO3)2

    NASA Astrophysics Data System (ADS)

    Janson, O.; Rousochatzakis, I.; Tsirlin, A. A.; Richter, J.; Skourski, Yu.; Rosner, H.

    2012-02-01

    We report the microscopic magnetic model for the spin-1/2 Heisenberg system CdCu2(BO3)2, one of the few quantum magnets showing the 1/2-magnetization plateau. Recent neutron diffraction experiments on this compound [M. Hase , Phys. Rev. BPLRBAQ0556-280510.1103/PhysRevB.80.104405 80, 104405 (2009)] evidenced long-range magnetic order, inconsistent with the previously suggested phenomenological magnetic model of isolated dimers and spin chains. Based on extensive density functional theory band structure calculations, exact diagonalizations, quantum Monte Carlo simulations, third-order perturbation theory as well as high-field magnetization measurements, we find that the magnetic properties of CdCu2(BO3)2 are accounted for by a frustrated quasi-2D magnetic model featuring four inequivalent exchange couplings: the leading antiferromagnetic coupling Jd within the structural Cu2O6 dimers, two interdimer couplings Jt1 and Jt2, forming magnetic tetramers, and a ferromagnetic coupling Jit between the tetramers. Based on comparison to the experimental data, we evaluate the ratios of the leading couplings Jd : Jt1 : Jt2 : Jit = 1 : 0.20 : 0.45 : -0.30, with Jd of about 178 K. The inequivalence of Jt1 and Jt2 largely lifts the frustration and triggers long-range antiferromagnetic ordering. The proposed model accounts correctly for the different magnetic moments localized on structurally inequivalent Cu atoms in the ground-state magnetic configuration. We extensively analyze the magnetic properties of this model, including a detailed description of the magnetically ordered ground state and its evolution in magnetic field with particular emphasis on the 1/2-magnetization plateau. Our results establish remarkable analogies to the Shastry-Sutherland model of SrCu2(BO3)2, and characterize the closely related CdCu2(BO3)2 as a material realization for the spin-1/2 decorated anisotropic Shastry-Sutherland lattice.

  17. ``Learning to Research'' in a Virtual Learning Environment: A Case Study on the Effectiveness of a Socio-constructivist Learning Design

    NASA Astrophysics Data System (ADS)

    López-Alonso, C.; Fernández-Pampillón, A.; de-Miguel, E.; Pita, G.

    Learning is the basis for research and lifelong training. The implementation of virtual environments for developing this competency requires the use of effective learning models. In this study we present an experiment in positive learning from the virtual campus of the Complutense University of Madrid (UCM). In order to carry it out we have used E-Ling, an e-learning environment that has been developed with an innovative didactic design based on a socio-constructivist learning approach. E-Ling has been used since 2006 to train future teachers and researchers in “learning to research”. Some of the results of this experiment have been statistically analysed in order to compare them with other learning models. From the obtained results we have concluded that E-Ling is a more productive proposal for developing competences in learning to research.

  18. Nuclear Engine System Simulation (NESS) version 2.0

    NASA Technical Reports Server (NTRS)

    Pelaccio, Dennis G.; Scheil, Christine M.; Petrosky, Lyman J.

    1993-01-01

    The topics are presented in viewgraph form and include the following; nuclear thermal propulsion (NTP) engine system analysis program development; nuclear thermal propulsion engine analysis capability requirements; team resources used to support NESS development; expanded liquid engine simulations (ELES) computer model; ELES verification examples; NESS program development evolution; past NTP ELES analysis code modifications and verifications; general NTP engine system features modeled by NESS; representative NTP expander, gas generator, and bleed engine system cycles modeled by NESS; NESS program overview; NESS program flow logic; enabler (NERVA type) nuclear thermal rocket engine; prismatic fuel elements and supports; reactor fuel and support element parameters; reactor parameters as a function of thrust level; internal shield sizing; and reactor thermal model.

  19. Fat Necrosis After Partial-Breast Irradiation With Brachytherapy or Electron Irradiation Versus Standard Whole-Breast Radiotherapy-4-Year Results of a Randomized Trial

    SciTech Connect

    Loevey, Katalin Fodor, Janos; Major, Tibor; Szabo, Eva; Orosz, Zsolt; Sulyok, Zoltan; Janvary, Levente; Froehlich, Georgina; Kasler, Miklos; Polgar, Csaba

    2007-11-01

    Purpose: To examine the incidence and clinical relevance of fat necrosis after accelerated partial-breast irradiation (PBI) using interstitial high-dose-rate brachytherapy (HDR-BT) in comparison with partial-breast electron irradiation (ELE) and whole-breast irradiation (WBI). Methods and Materials: Between 1998 and 2004, 258 early-stage breast cancer patients were randomized to receive 50 Gy WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 x 5.2 Gy HDR-BT (n = 88) or 50 Gy ELE (n = 40). The incidence of fat necrosis, its impact on cosmetic outcome, accompanying radiologic features, and clinical symptoms were evaluated. Results: The 4-year actuarial rate of fat necrosis was 31.1% for all patients, and 31.9%, 36.5%, and 17.7% after WBI, HDR-BT and ELE, respectively (p{sub WBI/HDR-BT} = 0.26; p{sub WBI/ELE} = 0.11; p{sub ELE/HDR-BT} = 0.025). The respective rate of asymptomatic fat necrosis was 20.2%, 25.3%, and 10% of patients. The incidence of symptomatic fat necrosis was not significantly different after WBI (8.5%), HDR-BT (11.4%), and ELE (7.5%). Symptomatic fat necrosis was significantly associated with a worse cosmetic outcome, whereas asymptomatic fat necrosis was not. Fat necrosis was detectable with mammography and/or ultrasound in each case. Additional imaging examinations were required in 21% of cases and aspiration cytology in 42%. Conclusions: Asymptomatic fat necrosis is a common adverse event of breast-conserving therapy, having no significant clinical relevance in the majority of the cases. The incidence of both symptomatic and asymptomatic fat necrosis is similar after conventional WBI and accelerated partial-breast HDR-BT.

  20. Gifford-McMahon/Joule-Thomson Refrigerator Cools to 2.5 K

    NASA Technical Reports Server (NTRS)

    Britcliffe, Michael; Fernandez, Jose; Hanson, Theodore

    2005-01-01

    A compact refrigerator designed specifically for cooling a microwave maser low-noise amplifier is capable of removing heat at a continuous rate of 180 mW at a temperature of 2.5 K. This refrigerator is a combination of (1) a commercial Gifford-McMahon (GM) refrigerator nominally rated for cooling to 4 K and (2) a Joule-Thomson (J-T) circuit. The GM refrigerator pre-cools the J-T circuit, which provides the final stage of cooling. The refrigerator is compact and capable of operating in any orientation. Moreover, in comparison with a typical refrigerator heretofore used to cool a maser to 4.5 K, this refrigerator is simpler and can be built at less than half the cost.

  1. Jaw tumor in primary hyperparathyroidism is not always a brown tumor

    PubMed Central

    Ennazk, Laila; El Mghari, Ghizlane; El Ansari, Nawal

    2016-01-01

    Summary Primary hyperparthyrodism (PHPT) is a common endocrine disease. It results from an inappropriate parathyroid hormone (PTH) secretion relative to serum ionized calcium level. Clinical manifestation of severe PHPT include bone disease called osteitis fibrosa cystica which reflects an increase osteoclastic resorption and osteoblastic activity. This high bone turnover is responsible of the occurrence of osteoclastomas, also named “brown tumors” (1). Rarely, PHPT may occur in inherited forms with association to fibrous jaw tumor that are unrelated to hyperparathyroidism. In this uncommon disease: hyperparathyroidism-jaw tumor (HPT-JT) syndrome, parathyroid tumor is frequently malignant and usually associated with nonendocrine malignancies (2). We report a case of a HPT-JT syndrome to focus on the differential diagnosis with brown tumors. PMID:27252751

  2. Low pollution combustor designs for CTOL engines - Results of the Experimental Clean Combustor Program

    NASA Technical Reports Server (NTRS)

    Roberts, R.; Peduzzi, A.; Niedzwiecki, R. W.

    1976-01-01

    The NASA/Pratt & Whitney Aircraft Experimental Clean Combustor Program is a multi-year, major contract effort. Primary program objectives are the generation of combustor technology for development of advanced commercial CTOL engines with lower exhaust emissions than current aircraft and demonstration of this technology in a full-scale JT9D engine in 1976. This paper describes the pollution and performance goals, Phase I and II test results, and the Phase III combustor hardware, pollution sampling techniques, and test plans. Best results were obtained with the Vorbix concept which employs multiple burning zones and improved fuel preparation and distribution. Substantial reductions were achieved in all pollutant categories, meeting the 1979 EPA standards for NOx, THC, and smoke when extrapolated to JT9D cycle conditions. The Vorbix concept additionally demonstrated the capability for acceptable altitude relight and did not appear to have unsolvable durability or exit temperature distribution problems.

  3. The effect of external magnetic field on the Raman peaks in manganites

    SciTech Connect

    Sahu, A. K.; Rout, G. C.

    2014-04-24

    We report here a microscopic theoretical model study exhibiting the effect of external magnetic field on the Raman excitation peaks in the CMR manganite system. The Hamiltonian consists of Jahn-Teller (J-T) distortion in e{sub g} band, the double exchange interaction and the Heisenberg spin-spin interaction. Further the phonons are coupled to e{sub g} band electrons, J-T distorted e{sub g} band and the double exchange interaction. The Raman spectral intensity is calculated from the imaginary part of the phonon Green function. The spectra exhibits three peaks besides a very weak high energy peak. The magnetic field effect on these peaks are reported.

  4. Tone generation by rotor-downstream strut interaction

    NASA Technical Reports Server (NTRS)

    Woodward, R. P.; Balombin, J. R.

    1983-01-01

    A JT15D fan stage was acoustically tested in the NASA Lewis anechoic chamber as part of the joint Lewis-Langley Research Center investigation of flight simulation techniques and flight effects using the JT15D engine as a common test vehicle. Suspected rotor-downstream support strut interaction was confirmed through the use of simulated support struts which were tested at three axial rotor-strut spacings. Tests were also performed with the struts removed. Inlet boundary layer suction in conjuction with an inflow control device was also explored. The removal of the boundary layer reduced the fan fundamental tone levels suggesting that the mounting and mating of such a device to the nacelle requires careful attention. With the same inflow control device installed good acoustic agreement was shown between the engine on an outdoor test stand and the fan in the anechoic chamber.

  5. Tone generation by rotor-downstream strut interaction

    NASA Technical Reports Server (NTRS)

    Woodward, R. P.; Balombin, J. R.

    1983-01-01

    A JT15D fan stage was acoustically tested in the NASA Lewis anechoic chamber as part of the joint Lewis-Langley Research Center investigation of flight simulation techniques and flight effects using the JT15D engine as a common test vehicle. Suspected rotor-downstream support strut interaction was confirmed through the use of simulated support struts which were tested at three axial rotor-strut spacings. Tests were also performed with the struts removed. Inlet boundary layer suction in conjunction with an inflow control device was also explored. The removal of the boundary layer reduced the fan fundamental tone levels suggesting that the mounting and mating of such a device to the nacelle requires careful attention. With the same inflow control device installed good acoustic agreement was shown between the engine on an outdoor test stand and the fan in the anechoic chamber.

  6. Vacuum insulation of the high energy negative ion source for fusion applicationa)

    NASA Astrophysics Data System (ADS)

    Kojima, A.; Hanada, M.; Hilmi, A.; Inoue, T.; Watanabe, K.; Taniguchi, M.; Kashiwagi, M.; Umeda, N.; Tobari, H.; Kobayashi, S.; Yamano, Y.; Grisham, L. R.

    2012-02-01

    Vacuum insulation on a large size negative ion accelerator with multiple extraction apertures and acceleration grids for fusion application was experimentally examined and designed. In the experiment, vacuum insulation characteristics were investigated in the JT-60 negative ion source with >1000 apertures on the grid with the surface area of ˜2 m2. The sustainable voltages varied with a square root of the gap lengths between the grids, and decreased with number of the apertures and with the surface area of the grids. Based on the obtained results, the JT-60SA (super advanced) negative ion source is designed to produce 22 A, 500 keV D- ion beams for 100 s.

  7. High performance infrared fast cooled detectors for missile applications

    NASA Astrophysics Data System (ADS)

    Reibel, Yann; Espuno, Laurent; Taalat, Rachid; Sultan, Ahmad; Cassaigne, Pierre; Matallah, Noura

    2016-05-01

    SOFRADIR was selected in the late 90's for the production of 320×256 MW detectors for major European missile programs. This experience has established our company as a key player in the field of missile programs. SOFRADIR has since developed a vast portfolio of lightweight, compact and high performance JT-based solutions for missiles. ALTAN is a 384x288 Mid Wave infrared detector with 15μm pixel pitch, and is offered in a miniature ultra-fast Joule- Thomson cooled Dewar. Since Sofradir offers both Indium Antimonide (InSb) and Mercury Cadmium Telluride technologies (MCT), we are able to deliver the detectors best suited to customers' needs. In this paper we are discussing different figures of merit for very compact and innovative JT-cooled detectors and are highlighting the challenges for infrared detection technologies.

  8. Core noise measurements from a small, general aviation turbofan engine

    NASA Astrophysics Data System (ADS)

    Reshotko, M.; Karchmer, A.

    1980-11-01

    As part of a program to investigate combustor and other core noises, simultaneous measurements of internal fluctuating pressure and far field noise were made with a JT15D turbofan engine. Acoustic waveguide probes, located in the engine at the combustor, at the turbine exit and in the core nozzle wall, were used to measure internal fluctuating pressures. Low frequency acoustic power determined at the core nozzle exit corresponds in level to the far field acoustic power at engine speeds below 65% of maximum, the approach condition. At engine speeds above 65% of maximum, the jet noise dominates in the far field, greatly exceeding that of the core. From coherence measurements, it is shown that the combustor is the dominant source of the low frequency core noise. The results obtained from the JT15D engine were compared with those obtained previously from a YF102 engine, both engines having reverse flow annular combustors and being in the same size class.

  9. Dynamic PID loop control

    SciTech Connect

    Pei, L.; Klebaner, A.; Theilacker, J.; Soyars, W.; Martinez, A.; Bossert, R.; DeGraff, B.; Darve, C.; /Fermilab

    2011-06-01

    The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters oscillation.

  10. On metal-insulator transition in cubic fullerides

    NASA Astrophysics Data System (ADS)

    Iwahara, Naoya; Chibotaru, Liviu

    The interplay between degenerate orbital and electron correlation is a key to characterize the electronic phases in, for example, transition metal compounds and alkali-doped fullerides. Besides, the degenerate orbital couples to spin and lattice degrees of freedom ,giving rise to exotic phenomena. Here, we develop the self-consistent Gutzwiller approach for the simultaneous treatment of the Jahn-Teller effect and electron correlation, and apply the methodology to reveal the nature of the ground electronic state of fullerides. For small Coulomb repulsion on site U, the fulleride is quasi degenerate correlated metal. With increase of U, we found the quantum phase transition from the metallic phase to JT split phase. In the latter, the Mott transition (MT) mainly develops in the half-filled subband, whereas the empty and the completely filled subbands are almost uninvolved. Therefore, we can qualify the metal-insulator transition in fullerides as an orbital selective MT induced by JT effect.

  11. Optical image encryption using a jigsaw transform for silhouette removal in interference-based methods and decryption with a single spatial light modulator.

    PubMed

    Kumar, Pramod; Joseph, Joby; Singh, Kehar

    2011-05-01

    Interference-based optical encryption schemes have an inherent silhouette problem due to the equipollent nature of the phase-only masks (POMs) generated using an analytical method. One of the earlier methods suggested that removing the problem by use of exchanging process between two masks increases the computational load. This shortcoming is overcome with a noniterative method using the jigsaw transformation (JT) in a single step, with improved security because the inverse JT of these masks, along with correct permutation keys that are necessary to decrypt the original image. The stringent alignment requirement of the POMs in two different arms during the experiment is removed with an alternative method using a single spatial light modulator. Experimental results are provided to demonstrate the decryption process with the proposed method.

  12. Effect of forward motion on engine noise

    NASA Technical Reports Server (NTRS)

    Blankenship, G. L.; Low, J. K. C.; Watkins, J. A.; Merriman, J. E.

    1977-01-01

    Methods used to determine a procedure for correcting static engine data for the effects of forward motion are described. Data were analyzed from airplane flyover and static-engine tests with a JT8D-109 low-bypass-ratio turbofan engine installed on a DC-9-30, with a CF6-6D high-bypass-ratio turbofan engine installed on a DC-10-10, and with a JT9D-59A high-bypass-ratio turbofan engine installed on a DC-10-40. The observed differences between the static and the flyover data bases are discussed in terms of noise generation, convective amplification, atmospheric propagation, and engine installation. The results indicate that each noise source must be adjusted separately for forward-motion and installation effects and then projected to flight conditions as a function of source-path angle, directivity angle, and acoustic range relative to the microphones on the ground.

  13. The design and flight test of an engine inlet bulk acoustic liner

    NASA Technical Reports Server (NTRS)

    Lester, H. C.; Preisser, J. S.; Parrott, T. L.

    1983-01-01

    This paper summarizes the design, fabrication and flight evaluation of a Kevlar acoustic liner configuration for a JT15D turbofan engine. The liner was designed to suppress, by a measurable amount, a dominant (13,0) BPF tone. This tone or spinning mode was produced for research purposes by installing 41 circumferentially distributed small diameter rods upstream of the 28 fan blades. Duct liner attenuations calculated by a finite element procedure were compared to far field power (insertion) losses deduced from flight data. The finite element program modeled the variable geometry of the JT15D inlet and used a uniform flow with a boundary layer roll-off to model the inlet flow field. Calculated liner losses were generally conservative. That is, measured far field power losses were generally greater than attenuations calculated by the finite element computer program.

  14. Development of improved-durability plasma sprayed ceramic coatings for gas turbine engines

    NASA Technical Reports Server (NTRS)

    Sumner, I. E.; Ruckle, D. L.

    1980-01-01

    As part of a NASA program to reduce fuel consumption of current commercial aircraft engines, methods were investigated for improving the durability of plasma sprayed ceramic coatings for use on vane platforms in the JT9D turbofan engine. Increased durability concepts under evaluation include use of improved strain tolerant microstructures and control of the substrate temperature during coating application. Initial burner rig tests conducted at temperatures of 1010 C (1850 F) indicate that improvements in cyclic life greater than 20:1 over previous ceramic coating systems were achieved. Three plasma sprayed coating systems applied to first stage vane platforms in the high pressure turbine were subjected to a 100-cycle JT9D engine endurance test with only minor damage occurring to the coatings.

  15. A 0.63 micrometers polarization maintaining optical fiber cable

    NASA Astrophysics Data System (ADS)

    Yoshida, H.; Kikuchi, Y.; Tamaki, Y.

    1986-11-01

    Polarization maintaining single mode optical fiber cable was developed with negligible small loss increase and high crosstalk for optical interferometric measuring system of JT-60 (Japan Atomic Energy Research Institute TOKAMAK-60). Optical interferometric measuring system is required for high precise non-contact measurement of distance or vibration. Polarization maintaining optical fiber enabled to measure them in extremely high electromagnetic field of JT-60. Developed cable is flame-resistant non-metallic type complex 16 fiber cable for 0.6 micron use, that has 8 polarization maintaining optical fibers (stress applying, called PANDA fiber) and 8 single mode optical fibers. This paper shows the experimental result and the possibility of manufacturing polarization maintaining single mode optical fiber cable for 0.63 micron use.

  16. Design of a valved moving magnet type linear compressor for a Joule-Thomson cryocooler

    NASA Astrophysics Data System (ADS)

    Wang, W. W.; Wang, L. Y.; Gan, Z. H.

    2014-01-01

    For temperatures around 4-6 K, Joule-Thomson (J-T) cryocoolers can achieve a higher efficiency than Stirling or pulse tube cryocoolers thus have been widely used in space. It is crucial for a J-T compressor to obtain a relatively high pressure ratio. With this concept, a valved moving magnet type linear compressor has been designed. This paper describes the design method and component structure of the linear compressor in detail. The electromagnetic force of linear motor, stiffness and stress distribution of flexure springs were calculated based on finite element method (FEM). System resonance was specially considered to achieve a high efficiency, and system vibration and heat dissipation problems were discussed. The design goal of the linear compressor is to achieve an efficiency of 80% and a lifetime longer than 5 years.

  17. Worm Algorithm simulations of the hole dynamics in the t-J model

    NASA Astrophysics Data System (ADS)

    Prokof'ev, Nikolai; Ruebenacker, Oliver

    2001-03-01

    In the limit of small J << t, relevant for HTSC materials and Mott-Hubbard systems, computer simulations have to be performed for large systems and at low temperatures. Despite convincing evidence against spin-charge separation obtained by various methods for J > 0.4t there is an ongoing argument that at smaller J spin-charge separation is still possible. Worm algorithm Monte Carlo simulations of the hole Green function for 0.1 < J/t < 0.4 were performed on lattices with up to 32x32 sites, and at temperature J/T = 40 (for the largest size). Spectral analysis reveals a single, delta-function sharp quasiparticle peak at the lowest edge of the spectrum and two distinct peaks above it at all studied J. We rule out the possibility of spin-charge separation in this parameter range, and present, apparently, the hole spectral function in the thermodynamic limit.

  18. Peritoneal dialysis in microencephaly.

    PubMed

    Peters, April

    2008-01-01

    J.T. was able to remain home in her familiar environment and receive safe and adequate treatment for her renal disease. J.T. had no infectious episodes or hospitalizations while under this unit's care for 35 months. She was also able to participate in her regular activities of daily living, interact with her family members, and travel on occasion, thus maintaining a good quality of life. Therefore, unit goals for her care were met. J.T.'s experience demonstrates that with proper teaching, preparation, and support from the dialysis care team working with a dedicated family, peritoneal dialysis can be an ideal modality for the treatment of ESRD in people with mental disabilities. PMID:19260611

  19. Preparation, crystallography and spectroscopic properties of the polymeric {(1-( E)-2-pyridinylmethylidene)semicarbazone)(aqua)copper(II)} sulphate dihydrate complex: Evidence of dynamic Jahn-Teller effect

    NASA Astrophysics Data System (ADS)

    Garbelini, Ellery R.; Ribeiro, Ronny Rocha; Hörner, Manfredo; Locatelli, Aline; Nunes, Fábio S.

    2011-05-01

    Pyridine-2-carbaldehyde semicarbazone ligand (HL) reacts with copper(II) sulphate in water solution to yield the coordination polymer [{Cu II(HL)(H 2O)(SO 4)} n] (1). The crystals are triclinic with space group P(-1) and the metal ion is occupying a distorted octahedral geometry. EPR results show that a dynamic Jahn-Teller (J-T) effect is operative in water solutions and also support the stability of the polymeric chains as they continue to show a characteristic half-field Δ mS = ±2 transitions. UV-visible spectrum analysis allowed access to the J-T stabilization energy of 5995 cm -1 in water. Thermogravimetric/differential thermal analysis curves showed a step-by-step decomposition of complex 1 with loss of water, release of SO 3 and oxidation of the semicarbazone ligand in the 30-422 °C range.

  20. QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALOONING MODES

    SciTech Connect

    LAO,LL; SNYDER,PB; LEONARD,AW; OIKAWA,T; OSBORNE,TH; PETRIE,TW; FERRON,JR; GROEBNER,RJ; HORTON,LD; KAMADA,Y; MURAKAMI,M; SAARELMA,S; STJOHN,HE; TURNBULL,AD; WILSON,HR

    2003-03-01

    A271 QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALOONING MODES. Several testable features of the working model of edge localized modes (ELMs) as intermediate toroidal mode number peeling-ballooning modes are evaluated quantitatively using DIII-D and JT-60U experimental data and the ELITE MHD stability code. These include the hypothesis that ELM sizes are related to the radial widths of the unstable MHD modes, the unstable modes have a strong ballooning character localized in the outboard bad curvature region, and ELM size generally becomes smaller at high edge collisionality. ELMs are triggered when the growth rates of the unstable MHD modes become significantly large. These testable features are consistent with many ELM observations in DIII-D and JT-60U discharges.

  1. Jahn-Teller-induced crossover of the paramagnetic response in the singly valent eg system LaMn7O12

    NASA Astrophysics Data System (ADS)

    Cabassi, R.; Bolzoni, F.; Gilioli, E.; Bissoli, F.; Prodi, A.; Gauzzi, A.

    2010-06-01

    We investigate the high-temperature magnetic and transport properties of LaMn7O12 , which displays a similar perovskitelike structure and the same single-valent Mn3+ properties of LaMnO3 but a much simpler Jahn-Teller (JT) distortion at TJT=650K . We find that the magnetic response of LaMn7O12 is similar to that of LaMnO3 below TJT , but strikingly different in the undistorted phase above TJT , where the Curie-Weiss susceptibility is strongly suppressed. Electrical resistivity and thermopower measurements unveil a concomitant crossover from nonadiabatic to adiabatic small polaron regime. This suggests that the above suppression is due to low-spin electron-hole dimers formed by the eg charge transfer between Mn sites and stabilized by the slow JT dynamics above TJT .

  2. A density functional study of the spin state energetics of polypyrazolylborato complexes of first-row transition metals.

    PubMed

    Gruden-Pavlović, M; Stepanović, S; Perić, M; Güell, M; Swart, M

    2014-07-28

    Density Functional Theory (DFT) was used to analyse and explain spin state energetics of first-row transition metals (Mn(II), Fe(II), Co(II); Cr(III), Mn(III), Fe(III), Co(III); Mn(IV)) in polypyrazolylborato complexes. We explored the effects of substitutions at the 3 and 5 positions of the pyrazolyl rings, as well as the influence of Jahn-Teller (JT) distortions on spin-state switching. Although the stabilizations due to JT distortion are sometimes substantial, this does not lead to switching of the spin ground-state. On the other hand, electron withdrawing or donating substituents do lead to significant changes in the spin-crossover (SCO) properties of the investigated complexes. PMID:24647963

  3. Vacuum insulation of the high energy negative ion source for fusion application

    SciTech Connect

    Kojima, A.; Hanada, M.; Inoue, T.; Watanabe, K.; Taniguchi, M.; Kashiwagi, M.; Umeda, N.; Tobari, H.; Hilmi, A.; Kobayashi, S.; Yamano, Y.; Grisham, L. R.

    2012-02-15

    Vacuum insulation on a large size negative ion accelerator with multiple extraction apertures and acceleration grids for fusion application was experimentally examined and designed. In the experiment, vacuum insulation characteristics were investigated in the JT-60 negative ion source with >1000 apertures on the grid with the surface area of {approx}2 m{sup 2}. The sustainable voltages varied with a square root of the gap lengths between the grids, and decreased with number of the apertures and with the surface area of the grids. Based on the obtained results, the JT-60SA (super advanced) negative ion source is designed to produce 22 A, 500 keV D{sup -} ion beams for 100 s.

  4. The effect of band Jahn-Teller distortion on the magnetoresistivity of manganites: a model study.

    PubMed

    Rout, G C; Panda, Saswati; Behera, S N

    2011-10-01

    We present a model study of magnetoresistance through the interplay of magnetisation, structural distortion and external magnetic field for the manganite systems. The manganite system is described by the Hamiltonian which consists of the s-d type double exchange interaction, Heisenberg spin-spin interaction among the core electrons, and the static and dynamic band Jahn-Teller (JT) interaction in the e(g) band. The relaxation time of the e(g) electron is found from the imaginary part of the Green's function using the total Hamiltonian consisting of the interactions due to the electron and phonon. The calculated resistivity exhibits a peak in the pure JT distorted insulating phase separating the low temperature metallic ferromagnetic phase and the high temperature paramagnetic phase. The resistivity is suppressed with the increase of the external magnetic field. The e(g) electron band splitting and its effect on magnetoresistivity is reported here.

  5. Effects of Structure on Magnetic Properties in La1-xSrxMnO3

    NASA Astrophysics Data System (ADS)

    Louca, Despo; Egami, Takeshi

    1996-03-01

    Pair Distribution Function (PDF) analysis was carried out on pulsed neutron powder diffaction data of x=0 and x=0.15 Sr-doped La1-xSrxMnO3 to study the local structure as a function of temperature. In the undoped case, strong Jahn-Teller (JT) distortions are observed with an elongation of x or y-axes. This has been established crystallographically and confirmed by PDF. A split in the PDF peak of the nearest neighbor Mn-O pairs is observed at 2.0 and 2.2 A with the ratio of 2:1. In the doped case, x=0.15, two levels of JT distor- tions are observed. At low temperatures, JT distortions are reduced by do- ping in the crystallographic picture, but PDF shows that some sites are dis- torted and some are not. As a result, the 2.0 A peak remains but the 2.2 A peak gets weaker. Ar room temperature, another secondary JT effect is obser- ved. This is seen by the breaking of symmetry between two undistorted dire- ctions. Real space refinement suggested the displacement of the B cation, Mn. At this temperature, in addition to the low T effects, splitting of the 2.0 A peak is observed to 1.89 A and 2.06 A. This is the first observance of such a structural change. This structural change should have huge effects on the change of resistivity at the Curie temperature. Physical implications will be discussed. This work was supported by NSF DMR93-00728.

  6. Identification of errors in the electron density measurements of a tangential interferometer/polarimeter system during a tokamak discharge

    SciTech Connect

    Arakawa, H.; Kawano, Y.; Itami, K.

    2012-10-15

    A new method for the comparative verification of electron density measurements obtained with a tangential interferometer and a polarimeter during a discharge is proposed. The possible errors associated with the interferometer and polarimeter are classified by the time required for their identification. Based on the characteristics of the errors, the fringe shift error of the interferometer and the low-frequency noise of the polarimeter were identified and corrected for the JT-60U tangential interferometer/polarimeter system.

  7. The Scientific Prototype - a proposed next step for the American MFE effort

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2013-10-01

    The Scientific prototype is the only logical next step for the American magnetic fusion effort. This poster is divided into two parts. The first is a description of the scientific prototype, a tokamak about the size of TFTR, JET and JT-60, but which runs steady state in DT and breeds its own tritium. The second is an examination of other proposed approaches for American MFE and why none constitute a viable alternative. W. Manheimer, J. Fusion Energy, 32, 419-421, 2013.

  8. An in vivo microperfusion study of distal tubule bicarbonate reabsorption in normal and ammonium chloride rats.

    PubMed Central

    Levine, D Z

    1985-01-01

    For many years it has been thought that distal nephron hydrogen ion secretion can be importantly modulated by factors such as sodium delivery, sodium avidity, and potassium stores. Free flow micropuncture studies have also indicated that the rate of bicarbonate delivery may also alter the rate of bicarbonate reabsorption. The present studies were undertaken to examine possible luminal influences on total CO2 reabsorption in microperfused distal tubules in the rat in vivo. Tubules from normal and acidotic rats were perfused with five solutions in a manner that induced changes in bicarbonate load, sodium and potassium fluxes (JNa, JK), and luminal sulfate concentration. in each collected perfusate, simultaneous analyses were undertaken to determine water reabsorption, Na, and K concentrations using graphite furnace atomic absorption spectroscopy and total CO2 by microcalorimetry. Using factorial analysis of covariance to account for confounding effects on total CO2 flux (JtCO2) such as water reabsorption, distal tubules of acidotic rats reabsorbed CO2 in the range of 50-112 pmol X min-1 X mm-1 X These JtCO2 values were not significantly correlated with HCO3 load, JNa, or JK despite changes in the latter from net reabsorption to net secretion. Distal tubules of rats with normal acid-base status had JtCO2 values which were neither significantly different from zero nor correlated with changes in JK and JNa. Further, doubling the load from 250-500 pmol/min (by doubling the perfusion rate of 25-mM HCO3 solutions) did not stimulate JtCO2 in these normal animals. Accordingly, these acute in vivo microperfusion studies indicate for the first time that neither load nor potassium or sodium fluxes are important modulators of distal tubule bicarbonate reabsorption. PMID:2982915

  9. Utilizing numerical techniques in turbofan inlet acoustic suppressor design

    NASA Astrophysics Data System (ADS)

    Baumeister, K. J.

    Numerical theories in conjunction with previously published analytical results are used to augment current analytical theories in the acoustic design of a turbofan inlet nacelle. In particular, a finite element-integral theory is used to study the effect of the inlet lip radius on the far field radiation pattern and to determine the optimum impedance in an actual engine environment. For some single mode JT15D data, the numerical theory and experiment are found to be in a good agreement.

  10. Anisotropic orbital occupation and Jahn-Teller distortion of orthorhombic YMnO{sub 3} epitaxial films: A combined experimental and theoretical study on polarization-dependent x-ray absorption spectroscopy

    SciTech Connect

    Haw, Shu-Chih; Chen, Shin-Ann; Lee, Jenn-Min; Lu, Kueih-Tzu; Lee, Ming-Tao; Pi, Tun-Wen; Chen, Jin-Ming E-mail: Zhiwei.Hu@cpfs.mpg.de; Lin, Pao-An; Lee, Chih-Hao; Hu, Zhiwei E-mail: Zhiwei.Hu@cpfs.mpg.de

    2014-04-21

    The b-axis oriented orthorhombic YMnO{sub 3} (o-YMnO{sub 3}) epitaxial films on a YAlO{sub 3} (010) substrate were fabricated with pulsed-laser deposition. The anisotropic orbital occupation and Jahn-Teller (JT) distortion of an o-YMnO{sub 3} film were investigated with polarization-dependent x-ray absorption spectra and configuration-interaction multiplet-cluster calculations. A significant energy difference, ∼3.8 eV, for the main white line along E//b and E//a in polarization-dependent Mn K-edge spectra of o-YMnO{sub 3} indicates an extraordinary JT distortion and significant anisotropic Mn–O bonding within the ab plane in the o-YMnO{sub 3} film. Most importantly, although the orbital occupation of 3d electrons in o-YMnO{sub 3} films is almost the same as that in single crystalline o-DyMnO{sub 3}, the JT distortion of o-YMnO{sub 3} films is larger than that of single crystalline o-DyMnO{sub 3}, deduced from the multiplet calculations. We speculate that this JT distortion predominantly contributes to the origin of the cycloidal spin deformation in bulk o-YMnO{sub 3}, because of a suppressed nearest-neighbor superexchange interaction and an enhanced next-nearest-neighbor superexchange interaction. These complementary results provide insight into the origin of the E-type magnetic configuration of o-YMnO{sub 3}.

  11. A Layman's Guide to Thrust Engine Development for Super/Hyper Sonic Flight.

    ERIC Educational Resources Information Center

    Thiesse, James L.

    The intention of this paper is to discuss the advances in thrust engines from the initial development of the J58/SR-71 (JT11D-20) of the U.S. Air Force's SR-71 Blackbird to the development of the RAM and SCRAM engines necessary to propel the new generations of high-flying super-speed aircraft. Engineering complexities suggest that the engines and…

  12. Fluctuating pressures on fan blades of a turbofan engine, flight test investigation

    NASA Astrophysics Data System (ADS)

    Schoenster, J. A.

    1985-02-01

    Miniature pressure transducers were used to measure the fluctuating pressure on the fan blades of a JT15D engine in flight to aid in understanding fan-noise generation. Although the blade pressures can be considered very useful in determining far-field noise sources in the subsonic fan-blade tip speeds, other mechanisms, and as shock waves in the transonic and supersonic fan-blade tip speeds, limit their usefulness in these higher speed ranges.

  13. Papers from the Fifth Regional Meeting of the Chicago Linguistic Society, April 18-19, 1969.

    ERIC Educational Resources Information Center

    Binnick, Robert I., Ed.; And Others

    The topics covered in this volume range over the entire field of linguistics. The authors are: A.L. Becker and D.G. Arms, W.R. Cantrall, G. Cohen, D.J. Darden, A. Davison, D. Elliott and others, J.E. Emonds, B. Fraser, G.M. Green, J.T. Heringer, L.R. Horn, L. Kartunnen, G. Lakoff, R. Lakoff, J.M. Lindholm, V.B. Makkai, J.L. Morgan, Y.C. Morin and…

  14. Improving Control in a Joule-Thomson Refrigerator

    NASA Technical Reports Server (NTRS)

    Borders, James; Pearson, David; Prina, Mauro

    2005-01-01

    A report discusses a modified design of a Joule-Thomson (JT) refrigerator under development to be incorporated into scientific instrumentation aboard a spacecraft. In most other JT refrigerators (including common household refrigerators), the temperature of the evaporator (the cold stage) is kept within a desired narrow range by turning a compressor on and off as needed. This mode of control is inadequate for the present refrigerator because a JT-refrigerator compressor performs poorly when the flow from its evaporator varies substantially, and this refrigerator is required to maintain adequate cooling power. The proposed design modifications include changes in the arrangement of heat exchangers, addition of a clamp that would afford a controlled heat leak from a warmer to a cooler stage to smooth out temperature fluctuations in the cooler stage, and incorporation of a proportional + integral + derivative (PID) control system that would regulate the heat leak to maintain the temperature of the evaporator within a desired narrow range while keeping the amount of liquid in the evaporator within a very narrow range in order to optimize the performance of the compressor. Novelty lies in combining the temperature- and cooling-power-regulating controls into a single control system.

  15. Local Jahn-Teller distortions and orbital ordering in Ba3Cu1 +xSb2 -xO9 investigated by neutron scattering

    NASA Astrophysics Data System (ADS)

    Li, Bing; Louca, Despina; Feygenson, Mikhail; Brown, Craig M.; Copley, John R. D.; Iida, Kazuki

    2016-01-01

    A spin-orbital quantum liquid state is theoretically proposed in the honeycomb lattice of Ba3CuSb2O9 , enabled by dynamic short-range correlations between the spin and orbital degrees of freedom. Using neutron diffraction, the local atomic structure of Ba3Cu1 +xSb2 -xO9 at x =0 and 0.1 is obtained via the pair density function analysis. The results indicate that both compositions exhibit local Jahn-Teller (JT) distortions with the elongated CuO3 octahedral configuration. In Ba3Cu1.1Sb1.9O9 , JT ordering of the distorted CuO3 octahedra gives rise to the orthorhombic symmetry with ferro-orbital order. On the other hand, in Ba3CuSb2O9 , even though the CuO3 octahedra are JT distorted, there is no long-range ordering hence the symmetry is hexagonal. Furthermore, the local singlet excitation at 5.8 meV observed in Ba3CuSb2O9 below 50 K is absent in Ba3Cu1.1Sb1.9O9 . Instead, an excitation at 2.5 meV is observed in the latter, which is likely associated with short-range spin order.

  16. Magnetic Reconnection Driven by the Nernst Effect

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Fox, W.; Bhattacharjee, A.; Joglekar, A.; Thomas, A.

    2013-10-01

    Magnetic reconnection in high-energy-density plasmas has been the subject of recent observations and PIC simulations. In laser-plasma experiments, laser-driven hot spots on a target can give rise to strong magnetic fields due to the Biermann battery effect. The hot spots can also produce strong heat flux perpendicular to the magnetic field, bringing into play the Nernst effect. Recently, using the Vlasov-Fokker-Planck code IMPACTA, which relies on a perturbative expansion of the electron distribution function holding ions fixed, Joglekar and Thomas (JT) have shown that the Nernst effect can play a significant role in magnetic reconnection. Since the domain of applicability of the expansion constrains the realm of validity of JT's results, we have undertaken a 2D PIC study of the Nernst effect, including complete kinetic dynamics of electrons as well as ions. We analyze the results using a broad range of dimensionless parameters, including plasma beta, the mass ratio of electrons and ions, and the Lundquist and Nernst numbers. We have found that the Nernst term contributes dominantly to support the the out-of-plane electric field upstream of the reconnection layer, consistent with JT's results. Variations on these results as a function of plasma parameters will be discussed.

  17. High Resolution Cavity Ring Down Spectroscopy of the 3^{1}_{0} and 3^{1}_{0} 4^{1}_{0} Bands of the ˜{A}^2E^'' State of NO_3 Radical

    NASA Astrophysics Data System (ADS)

    Roudjane, Mourad; Codd, Terrance J.; Miller, Terry A.

    2013-06-01

    The NO_3 radical is expected to exhibit a Jahn-Teller (JT) effect in its degenerate ˜{A}^2E^'' electronic state. In the ˜{A} state there are two JT active modes, ν_3 and ν_4 (e^' stretch and in-plane bend respectively). Theoretical work has predicted that the JT effect in the ˜{A} state should be quite strong and approach the static case where the molecule is permanently distorted to a lower symmetry geometry. A more comprehensive understanding of its structure can be achieved using high resolution rotationally resolved absorption spectroscopy of its different vibronic bands. The high resolution absorption spectra of 3^{1}_{0} and 3^{1}_{0} 4^{1}_{0} vibronic bands of the ˜{A} ^2E^'' excited state of NO_3 have been successfully recorded for the first time using our jet cooled cavity ring down apparatus. These parallel bands are vibronically allowed transitions and shows the same contour. An oblate symmetric top model Hamiltonian including both centrifugal distortion and spin rotation terms is used to analyze the spectrum. The rotational analysis of this band, supported by combination differences, demonstrate the existence of doubled lines as were observed for 4^{n}_{0} (n=1,3) bands. E. Hirota, T. Ishiwata, K. Kawaguchi, M. Fujitake, N. Ohashi, and I. Tanaka, J. Chem. Phys., {107}, 2829, 1997. Roudjane, M. et al. 67{^{th}} OSU International Symposium on Molecular Spectroscopy, The Ohio State University, Columbus, Ohio, 2011, talk TI-03.

  18. A closed-cycle refrigerator for cooling maser amplifiers below 4 Kelvin

    NASA Technical Reports Server (NTRS)

    Britcliffe, M.

    1989-01-01

    A helium refrigerator utilizing the Gifford-McMahon/Joule-Thomson (GM/JT) cycle was designed and tested to demonstrate the feasibility of using small closed-cycle refrigerators as an alternative to batch-filled cryostats for operating temperatures below 4 K. The systems could be used to cool low-noise microwave maser amplifiers located in large parabolic antennas. These antennas tilt vertically, making conventional liquid-filled dewars difficult to use. The system could also be used for a non-tilting beam waveguide antenna to reduce the helium consumption of a liquid helium cryostat. The prototype system is adjustable to provide 700 mW of cooling at 2.5 K to 3 W at 4.3 K. Performance of the unit is not significantly affected by physical orientation. The volume occupied by the refrigerator is less than 0.1 cu m. Two JT expansion stages are used to maximize cooling capacity per unit mass flow. The heat exchangers were designed to produce minimum pressure drop in the return gas stream. Pressure drop for the entire JT return circuit is less than 5 kpa at a mass flow of 0.06 g/sec when operating at 2.5 K.

  19. Local Jahn-Teller distortions and orbital ordering in Ba3Cu1+xSb2-xO9 investigated by neutron scattering

    DOE PAGES

    Li, Bing; Feygenson, Mikhail; Brown, Craig M.; Copley, John R. D.; Iida, Kazuki

    2016-01-15

    In this study, a spin-orbital quantum liquid state is theoretically proposed in the honeycomb lattice of Ba3CuSb2O9, enabled by dynamic short-range correlations between the spin and orbital degrees of freedom. Using neutron diffraction, the local atomic structure of Ba3Cu1+xSb2-xO9 at x = 0 and 0.1 is obtained via the pair density function analysis. The results indicate that both compositions exhibit local Jahn-Teller (JT) distortions with the elongated CuO3 octahedral configuration. In Ba3Cu1.1Sb1.9O9, JT ordering of the distorted CuO3 octahedra gives rise to the orthorhombic symmetry with ferro-orbital order. On the other hand, in Ba3CuSb2O9, even though the CuO3 octahedra aremore » JT distorted, there is no long-range ordering hence the symmetry is hexagonal. Furthermore, the local singlet excitation at 5.8 meV observed in Ba3CuSb2O9 below 50 K is absent in Ba3Cu1.1Sb1.9O9. Instead, an excitation at 2.5 meV is observed in the latter, which is likely associated with short-range spin order.« less

  20. Joule-Thomson cryocooler with neon and nitrogen mixture using commercial air-conditioning compressors

    NASA Astrophysics Data System (ADS)

    Lee, Jisung; Oh, Haejin; Baek, Seungwhan; Lee, Cheonkyu; Jeong, Sangkwon

    2014-01-01

    A 2-stage mixed refrigerant (MR) Joule-Thomson (JT) cryocooler was designed for cooling high temperature superconducting cable below 70 K. The low temperature cycle was to operate with neon-nitrogen mixture, and the required compression ratio was approximately 24 when the suction pressure was 100 kPa. The high compression ratio of 24, the low pressure of 100 kPa at compressor suction, and the working fluid with high heat of compression were challenging issues to existing typical compression systems. We developed an innovative compression system with commercial oil-lubricated air-conditioning compressors. They were 2-stage rotary compressors originally designed for R410Aand connected in series. The compressors were modified to accommodate effective intercooling at every stage to alleviate compressor overheating problem. Additionally, fine-grade three-stage oil filters, an adsorber, and driers were installed at the discharge line to avoid a potential clogging problem from oil mist and moisture at low temperature sections. The present compression system was specifically demonstrated with a neon-nitrogen MR JT cryocooler. The operating pressure ratio was able to meet the designed specifications, and the recorded no-load mini mum temperature was 63.5 K . Commercial air-conditioning compressors were successfully applied to the high-c ompression ratio MR JT cryocooler with adequate modification using off-the-shelf components.

  1. Symmetry-adapted excited states for the T{sub 1u}(direct-product)h{sub g} Jahn-Teller system

    SciTech Connect

    Qiu, Q. C.; Dunn, J. L.; Bates, C. A.

    2001-08-15

    Jahn-Teller (JT) systems typically contain a set of equivalent-energy wells in the lowest adiabatic potential-energy surface (APES). Quantum-mechanical tunneling between these wells (the dynamic JT effect) must be allowed for by taking appropriate symmetrized combinations of oscillator-type states associated with the wells. It is important to be able to describe the excited states of such systems for a number of reasons. One particular reason is that they are required for the calculation of second-order vibronic reduction factors, which in turn are useful for modeling experimental data using effective Hamiltonians. In this paper, projection-operator techniques are used to obtain general expressions for the symmetry-adapted excited states of the icosahedral T{sub 1u}(direct-product)h{sub g} JT system for the case of D{sub 5d} minima in the APES. Analytical expressions for the states and their energies for one-phonon excitation are given explicitly. The energies of a selection of states with two-phonon excitations are also obtained and plotted. The results obtained in this paper are applicable to the C{sub 60}{sup -} molecule.

  2. Symmetry-adapted excited states for the T1u⊗hg Jahn-Teller system

    NASA Astrophysics Data System (ADS)

    Qiu, Q. C.; Dunn, J. L.; Bates, C. A.

    2001-08-01

    Jahn-Teller (JT) systems typically contain a set of equivalent-energy wells in the lowest adiabatic potential-energy surface (APES). Quantum-mechanical tunneling between these wells (the dynamic JT effect) must be allowed for by taking appropriate symmetrized combinations of oscillator-type states associated with the wells. It is important to be able to describe the excited states of such systems for a number of reasons. One particular reason is that they are required for the calculation of second-order vibronic reduction factors, which in turn are useful for modeling experimental data using effective Hamiltonians. In this paper, projection-operator techniques are used to obtain general expressions for the symmetry-adapted excited states of the icosahedral T1u⊗hg JT system for the case of D5d minima in the APES. Analytical expressions for the states and their energies for one-phonon excitation are given explicitly. The energies of a selection of states with two-phonon excitations are also obtained and plotted. The results obtained in this paper are applicable to the C-60 molecule.

  3. Optimization of a Two-Stage Adr for the Soft X-Ray Spectrometer (sxs) Instrument on the Astro-H Mission

    NASA Astrophysics Data System (ADS)

    Shirron, P. J.; Kimball, M. O.; Wegel, D. C.; Miller, F. K.

    2010-04-01

    NASA/Goddard Space Flight Center has begun developing the Soft X-ray Spectrometer (SXS) instrument that will be flown on the Japanese Astro-H mission. The SXS's 36-pixel detector array will be cooled to 50 mK using a two-stage adiabatic demagnetization refrigerator (ADR). A complicating factor for its design is that the ADR will be integrated into a superfluid helium dewar at 1.3 K that will be coupled to a 1.8 K Joule-Thomson (JT) stage through a heat switch. When liquid helium is present, the coupling will be weak, and the JT stage will act primarily as a shield to reduce parasitic heat loads. When the liquid is depleted, the heat switch will couple more strongly so that the ADR can continue to operate using the JT stage as its heat sink. A two-stage ADR is the most mass efficient option and it has the operational flexibility to work well with a stored cryogen and a cryocooler. The stages are operated independently, and this opens up a very large parameter space for optimizing the design. This paper discusses the optimization process and most relevant trades considered in the design of the SXS ADR, and its expected performance.

  4. The Astro-H Soft X-ray Spectrometer (SXS)

    NASA Astrophysics Data System (ADS)

    Porter, F. Scott; Fujimoto, Ryuichi; Kelley, Richard L.; Kilbourne, Caroline A.; Mitsuda, Kazuhiasa; Ohashi, Takaya; Astro-H/SXS Collaboration

    2009-12-01

    The Soft-X-ray Spectrometer (SXS) is a high spectral resolution, cryogenic x-ray spectrometer that will fly on the Japan/U.S. Astro-H observatory in 2014. The SXS is composed of a 36 pixel, imaging, x-ray calorimeter array that will operate at 0.05 K utilizing a 2-stage adiabatic demagnetization refrigerator and a redundant pre-cooler design using both a 40 liter liquid helium tank and a 1.7 K Joule-Thomson (JT) cryocooler. Additional redundant Stirling cycle coolers provide pre-cooling for the (JT) and cool the outer thermal shields for the JT and the helium tank. The detector system, while similar to that flown on Suzaku, is composed of larger 0.81×0.81mm pixels, but has significantly better performance, currently predicted to be better than 4 eV FWHM at 6 keV with 95% quantum efficiency. This instrument is the result of a close collaboration between many institutions in the U.S. and Japan over the last 25 years. Here we will present an overview of the SXS instrument, the SXS cooling system, and recent laboratory improvements to the detector system.

  5. Operating modes and cooling capabilities of the 3-stage ADR developed for the Soft-X-ray Spectrometer instrument on Astro-H

    NASA Astrophysics Data System (ADS)

    Shirron, Peter J.; Kimball, Mark O.; James, Bryan L.; Muench, Theodore; DiPirro, Michael J.; Letmate, Richard V.; Sampson, Michael A.; Bialas, Tom G.; Sneiderman, Gary A.; Porter, Frederick S.; Kelley, Richard L.

    2016-03-01

    A 3-stage adiabatic demagnetization refrigerator (ADR) (Shirron et al., 2012) is used on the Soft X-ray Spectrometer instrument (Mitsuda et al., 2010) on Astro-H (Takahashi et al., 2010) [3] to cool a 6 × 6 array of X-ray microcalorimeters to 50 mK. The ADR is supported by a cryogenic system (Fujimoto et al., 2010) consisting of a superfluid helium tank, a 4.5 K Joule-Thomson (JT) cryocooler, and additional 2-stage Stirling cryocoolers that pre-cool the JT cooler and cool radiation shields within the cryostat. The ADR is configured so that it can use either the liquid helium or the JT cryocooler as its heat sink, giving the instrument an unusual degree of tolerance for component failures or degradation in the cryogenic system. The flight detector assembly, ADR and dewar were integrated into the flight dewar in early 2014, and have since been extensively characterized and calibrated. This paper summarizes the operation and performance of the ADR in all of its operating modes.

  6. 100 s extraction of negative ion beams by using actively temperature-controlled plasma grid

    SciTech Connect

    Kojima, A. Hanada, M.; Yoshida, M.; Tobari, H.; Kashiwagi, M.; Umeda, N.; Watanabe, K.; Grisham, L. R.

    2014-02-15

    Long pulse beam extraction with a current density of 120 A/m{sup 2} for 100 s has been achieved with a newly developed plasma grid (PG) for the JT-60SA negative ion source which is designed to produce high power and long pulse beams with a negative ion current of 130 A/m{sup 2} (22 A) and a pulse length of 100 s. The PG temperature is regulated by fluorinated fluids in order to keep the high PG temperature for the cesium-seeded negative ion production. The time constant for temperature controllability of the PG was measured to be below 10 s, which was mainly determined by the heat transfer coefficient of the fluorinated fluid. The measured decay time of the negative ion current extracted from the actively temperature-controlled PG was 430 s which was sufficient for the JT-60SA requirement, and much longer than that by inertial-cooling PG of 60 s. Obtained results of the long pulse capability are utilized to design the full size PG for the JT-60SA negative ion source.

  7. Hot isostatically pressed manufacture of high strength MERL 76 disk and seal shapes

    NASA Technical Reports Server (NTRS)

    Eng, R. D.; Evans, D. J.

    1982-01-01

    The feasibility of using MERL 76, an advanced high strength direct hot isostatic pressed powder metallurgy superalloy, as a full scale component in a high technology, long life, commercial turbine engine were demonstrated. The component was a JT9D first stage turbine disk. The JT9D disk rim temperature capability was increased by at least 22 C and the weight of JT9D high pressure turbine rotating components was reduced by at least 35 pounds by replacement of forged Superwaspaloy components with hot isostatic pressed (HIP) MERL 76 components. The process control plan and acceptance criteria for manufacture of MERL 76 HIP consolidated components were generated. Disk components were manufactured for spin/burst rig test, experimental engine tests, and design data generation, which established lower design properties including tensile, stress-rupture, 0.2% creep and notched (Kt = 2.5) low cycle fatigue properties, Sonntag, fatigue crack propagation, and low cycle fatigue crack threshold data. Direct HIP MERL 76, when compared to conventionally forged Superwaspaloy, is demonstrated to be superior in mechanical properties, increased rim temperature capability, reduced component weight, and reduced material cost by at least 30% based on 1980 costs.

  8. Physics issues of high bootstrap current tokamaks

    NASA Astrophysics Data System (ADS)

    Ozeki, T.; Azumi, M.; Ishii, Y.; Kishimoto, Y.; Fu, G. Y.; Fujita, T.; Rewoldt, G.; Kikuchi, M.; Kamada, Y.; Kimura, H.; Kusama, Y.; Saigusa, M.; Ide, S.; Shirai, H.

    1997-05-01

    Physics issues of a tokamak plasma with a hollow current profile produced by a large bootstrap current are discussed based on experiments in JT-60U. An internal transport barrier for both ions and electrons was obtained just inside the radius of zero magnetic shear in JT-60U. Analysis of the toroidal ITG microinstability by toroidal particle simulation shows that weak and negative shear reduces the toroidal coupling and suppresses the ITG mode. A hard beta limit was observed in JT-60U negative shear experiments. Ideal MHD mode analysis shows that the n = 1 pressure-driven kink mode is a plausible candidate. One of the methods to improve the beta limit against the kink mode is to widen the negative shear region, which can induce a broader pressure profile resulting in a higher beta limit. The TAE mode for the hollow current profile is less unstable than that for the monotonic current profile. The reason is that the continuum gaps near the zero shear region are not aligned when the radius of qmin is close to the region of high $\</p>
      </li>

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      <p><a target=Photophysics of barrelene: The Jahn-Teller and pseudo-Jahn-Teller effects

    NASA Astrophysics Data System (ADS)

    Ghanta, Susanta

    2016-04-01

    The static and dynamic aspects of Jahn-Teller(JT) and pseudo-Jahn-Teller(PJT) interactions between ground (X˜2A2‧) and first three excited electronic states (A˜2E‧ , B˜2E″ and C˜2A‧1) of bicyclo- [2,2,2]-octa-2,5,7-triene (barrelene) radical cation (Bl+) are theoretically investigated here. This belongs to the (E + E) ⊗ e and (E + A) ⊗ e JT-PJT class of compounds as described by the symmetry of the electronic states and the molecular point group. The complex vibronic dynamics on the coupled electronic states of the cation is simulated by both time-independent and time-dependent wave packet propagation method using multi configuration time-dependent Hartree scheme. The JT effects in the A˜ and B˜ electronic states and the PJT coupling between the B˜ and C˜ electronic states of Bl+ are found very strong. The final theoretical results are compared with the experimental results.

  9. Visualization of the solid-liquid equilibria for non-flammable mixed refrigerants

    NASA Astrophysics Data System (ADS)

    Lee, Cheonkyu; Yoo, Junghyun; Lee, Jisung; Jeong, Sangkwon

    2016-04-01

    Non-flammable mixed refrigerant (NF-MR) Joule Thomson (J-T) refrigerators have desirable characteristics and wide cooling temperature range compared to those of pure J-T refrigerators. However, the operating challenge due to freezing is a critical issue to realize this type of refrigerator. In this paper, the solid-liquid phase equilibria (i.e. freezing point) of the NF-MR which is composed of Argon (Ar), R14 (CF4), and R218 (C3F8), has been experimentally investigated by a visualized apparatus. The accuracy of the apparatus is experimentally verified with pure refrigerants and selected binary mixed refrigerants. Freezing points of the ternary NF-MRs have been measured with the molar compositions from 0.1 to 0.8 for each component. Each test result is simultaneously acquired by a camcorder for visual inspection and temperature measurement during a warming process. Experimental results reveal that the specific MR, with R14 molar composition higher than 0.4, can achieve remarkably low freezing temperature even below 77 K. These unusual freezing point depression characteristics of the MR can be a useful information for designing a cryogenic MR J-T refrigerator to reach temperatures less than 77 K.

  10. The Liquefaction of Hydrogen and Helium Using Small Coolers

    SciTech Connect

    Green, Michael A.

    2006-02-12

    This report discusses the history of the liquefaction of hydrogen and helium using small coolers. This history dates form the 1960's when two stage GM coolers capable of reaching 7 K were used to liquefy helium and hydrogen by suing an added compressor and J-T circuit. Liquefaction using the added circuit failed to become mainstream because the J-T valve and heat exchanger clogged because of impurities in the gas being liquefied. Liquefaction using a GM cooler without an added J-T circuit proved to be difficult because the first stage was not used to pre-cool the gas coming to the second stage of the cooler. Once the gas being liquefied was pre-cooled using the cooler first stage, improvements in the liquefaction rates were noted. The advent of low temperature pulse tube cooler (down to 2.5 K) permitted one to achieve dramatic improvement is the liquefactions rates for helium. Similar but less dramatic improvements are expected for hydrogen as well. Using the PT-415 cooler, one can expect liquefaction rates of 15 to 20 liters per day for helium or hydrogen provided the heat leak into the cooler and the storage vessel is low. A hydrogen liquefier for MICE is presented at the end of this report.

  11. Proceedings of the 7th International Cryocooler Conference, part 2

    NASA Astrophysics Data System (ADS)

    1993-04-01

    Partial contents include: SDIO and Air Force Cryocooler Technology Developments at USAF Phillips Laboratory; JPL Cryocooler Development and Test Program Overview; Development and Demonstration of a Diaphragm Stirling 65 K Standard Spacecraft Cryocooler; Stirling Space Cooler; Thermal, Vibration, and Reliability Test Results for a Balanced 80 K Cryocooler; Spacecraft Cooler Characterization; Performance of a Long Life Reverse Brayton Cryocooler; SDI Cryocooler Producibility Program; Miniature Pulse Tube Cooler; Flow Patterns Intrinsic to the Pulse Tube Refrigerator; Experimental Investigation of the Regenerative Magnetic Refrigerator Operating Between 4.2 K and 1.8 K; A 4 K Gifford-McMahon Refrigerator for Radio Astronomy; A Stirling Cycle Cryocooler for 4 K Applications; Regenerator Performance and Refrigeration Mechanism for 4 K GM Refrigerator Using Rare Earth Compound Regenerator Materials; Superfluid Stirling Refrigerator with a Counterflow Regenerator; Graded and Nongraded Regenerator Performance; Evolution of the 10 K Periodic Sorption Refrigerator Concept; Development of a Periodic 10 K Sorption Cryocooler; Assessment of a Hydrogen Joule-Thomson Expander and Vanadium Hydride Sorption Beds for 20 K Cryocoolers; Design of a Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cryocooler; JT Cryostat with Liquid-Solid Cryogen Reservoir; Design of A Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cooler; Phase Equilibria in Cryogenic Mixtures.

  12. Proceedings of the 7th International Cryocooler Conference, part 3

    NASA Astrophysics Data System (ADS)

    1993-04-01

    Partial contents include: SDIO and Air Force Cryocooler Technology Developments at USAF Phillips Laboratory; JPL Cryocooler Development and Test Program Overview; Development and Demonstration of a Diaphragm Stirling 65 K Standard Spacecraft Cryocooler; Stirling Space Cooler; Thermal, Vibration, and Reliability Test Results for a Balanced 80 K Cryocooler; Spacecraft Cooler Characterization; Performance of a Long Life Reverse Brayton Cryocooler; SDI Cryocooler Producibility Program; Miniature Pulse Tube Cooler; Flow Patterns Intrinsic to the Pulse Tube Refrigerator; Experimental Investigation of the Regenerative Magnetic Refrigerator Operating Between 4.2 K and 1.8 K; A 4 K Gifford-McMahon Refrigerator for Radio Astronomy; A Stirling Cycle Cryocooler for 4 K Applications; Regenerator Performance and Refrigeration Mechanism for 4 K GM Refrigerator Using Rare Earth Compound Regenerator Materials; Superfluid Stirling Refrigerator with a Counterflow Regenerator; Graded and Nongraded Regenerator Performance; Evolution of the 10 K Periodic Sorption Refrigerator Concept; Development of a Periodic 10 K Sorption Cryocooler; Assessment of a Hydrogen Joule-Thomson Expander and Vanadium Hydride Sorption Beds for 20 K Cryocoolers; Design of a Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cryocooler; JT Cryostat with Liquid-Solid Cryogen Reservoir; Design of A Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cooler; Phase Equilibria in Cryogenic Mixtures.

  13. Proceedings of the 7th International Cryocooler Conference, part 1

    NASA Astrophysics Data System (ADS)

    1993-04-01

    Partial contents include: SDIO and Air Force Cryocooler Technology Developments at USAF Phillips Laboratory; JPL Cryocooler Development and Test Program Overview; Development and Demonstration of a Diaphragm Stirling 65 K Standard Spacecraft Cryocooler; Stirling Space Cooler; Thermal, Vibration, and Reliability Test Results for a Balanced 80 K Cryocooler; Spacecraft Cooler Characterization; Performance of a Long Life Reverse Brayton Cryocooler; SDI Cryocooler Producibility Program; Miniature Pulse Tube Cooler; Flow Patterns Intrinsic to the Pulse Tube Refrigerator; Experimental Investigation of the Regenerative Magnetic Refrigerator Operating Between 4.2 K and 1.8 K; A 4 K Gifford-McMahon Refrigerator for Radio Astronomy; A Stirling Cycle Cryocooler for 4 K Applications; Regenerator Performance and Refrigeration Mechanism for 4 K GM Refrigerator Using Rare Earth Compound Regenerator Materials; Superfluid Stirling Refrigerator with a Counterflow Regenerator; Graded and Nongraded Regenerator Performance; Evolution of the 10 K Periodic Sorption Refrigerator Concept; Development of a Periodic 10 K Sorption Cryocooler; Assessment of a Hydrogen Joule-Thomson Expander and Vanadium Hydride Sorption Beds for 20 K Cryocoolers; Design of a Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cryocooler; JT Cryostat with Liquid-Solid Cryogen Reservoir; Design of A Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cooler; Phase Equilibria in Cryogenic Mixtures.

  14. The 7th International Cryocooler Conference

    NASA Astrophysics Data System (ADS)

    1993-04-01

    The partial contents of this document include the following: SDIO and Air Force Cryocooler Technology Developments at USAF Phillips Laboratory; JPL Cryocooler Development and Test Program Overview; Development and Demonstration of a Diaphragm Stirling 65 K Standard Spacecraft Cryocooler; Stirling Space Cooler; Thermal, Vibration, and Reliability Test Results for a Balanced 80 K Cryocooler; Spacecraft Cooler Characterization; Performance of a Long Life Reverse Brayton Cryocooler; SDI Cryocooler Producibility Program; Miniature Pulse Tube Cooler; Flow Patterns Intrinsic to the Pulse Tube Refrigerator; Experimental Investigation of the Regenerative Magnetic Refrigerator Operating Between 4.2 K and 1.8 K; A 4 K Gifford-McMahon Refrigerator for Radio Astronomy; A Stirling Cycle Cryocooler for 4 K Applications; Regenerator Performance and Refrigeration Mechanism for 4 K GM Refrigerator Using Rare Earth Compound Regenerator Materials; Superfluid Stirling Refrigerator with a Counterflow Regenerator; Graded and Nongraded Regenerator Performance; Evolution of the 10 K Periodic Sorption Refrigerator Concept; Development of a Periodic 10 K Sorption Cryocooler; Assessment of a Hydrogen Joule-Thomson Expander and Vanadium Hydride Sorption Beds for 20 K Cryocoolers; Design of a Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cryocooler; JT Cryostat with Liquid-Solid Cryogen Reservoir; Design of A Metal Hydride Sorption Cryocooler System; Linear Compressor for JT Cooler; and Phase Equilibria in Cryogenic Mixtures.

  15. Operating Modes and Cooling Capabilities of the Flight ADR for the SXS Instrument on Astro-H

    NASA Technical Reports Server (NTRS)

    Shirron, Peter; Kimball, Mark; DiPirro, Michael

    2015-01-01

    The microcalorimeter array on the Soft X-ray Spectrometer instrument on Astro-H requires cooling to 50 mK, which will be accomplished by a 3-stage adiabatic demagnetization refrigerator (ADR). The ADR is surrounded by a cryogenic system consisting of a superfluid helium tank, a 4.5 K Joule-Thomson (JT) cryocooler, and additional 2-stage Stirling cryocoolers that pre-cool the JT cooler and radiation shields within the cryostat. The unique ADR design allows the instrument to meet all of its science requirements using either the stored cryogen or the JT cryocooler as its heat sink, giving the instrument an unusual degree of tolerance for component failures or degradation in the cryogenic system. The flight detector assembly, ADR and dewar were integrated in early 2014, and have since been extensively characterized and calibrated. At present, the four instruments are being integrated with the spacecraft in preparation for an early 2016 launch. This presentation summarizes the operation and performance of the ADR in all of its operating modes.

  16. Comparison of Fracture Methodologies for Flaw Stability Analysis of Storage Tanks

    SciTech Connect

    LAM, POH-SANG

    2004-04-05

    Fracture mechanics methodologies for flaw stability analysis of a storage tank were compared in terms of the maximum stable through-wall flaw sizes or ''instability lengths.'' The comparison was made at a full range of stress loading at a specific set of mechanical properties of A285 carbon steel and with the actual tank configuration. The two general methodologies, the J-integral-tearing modulus (J-T) and the failure assessment diagram (FAD), and their specific estimation schemes were evaluated. A finite element analysis of a flawed tank was also performed for validating the J estimation scheme with curvature correction and for constructing the finite element-based FAD. The calculated instability crack lengths show that the J-T methodology that uses an estimated scheme, and the material-specific FAD, most closely approximate the result calculated with finite element analysis for the stress range that bounds those expected at the highest fill levels in the storage tanks. The results from the other FAD methods show instability lengths less than the J-T results over this range.

  17. Temperature-dependent exchange interaction in molecular magnets Cu(hfac)2L(R) studied by EPR: methodology and interpretations.

    PubMed

    Veber, Sergey L; Fedin, Matvey V; Maryunina, Ksenia Yu; Potapov, Alexey; Goldfarb, Daniella; Reijerse, Edward; Lubitz, Wolfgang; Sagdeev, Renad Z; Ovcharenko, Victor I; Bagryanskaya, Elena G

    2011-10-17

    Exchange-coupled spin triads nitroxide-copper(II)-nitroxide are the key building blocks of molecular magnets Cu(hfac)(2)L(R). These compounds exhibit thermally induced structural rearrangements and spin transitions, where the exchange interaction between spins of copper(II) ion and nitroxide radicals changes typically by 1 order of magnitude. We have shown previously that electron paramagnetic resonance (EPR) spectroscopy is sensitive to the observed magnetic anomalies and provides information on both inter- and intracluster exchange interactions. The value of intracluster exchange interaction is temperature-dependent (J(T)), that can be accessed by monitoring the effective g-factor of the spin triad as a function of temperature (g(eff)(T)). This paper describes approaches for studying the g(eff)(T) and J(T) dependences and establishes correlations between them. The experimentally obtained g(eff)(T) dependences are interpreted using three different models for the mechanism of structural rearrangements on the molecular level leading to different meanings of the J(T) function. The contributions from these mechanisms and their manifestations in X-ray, magnetic susceptibility and EPR data are discussed.

  18. Study of turboprop systems reliability and maintenance costs

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The overall reliability and maintenance costs (R&MC's) of past and current turboprop systems were examined. Maintenance cost drivers were found to be scheduled overhaul (40%), lack of modularity particularly in the propeller and reduction gearbox, and lack of inherent durability (reliability) of some parts. Comparisons were made between the 501-D13/54H60 turboprop system and the widely used JT8D turbofan. It was found that the total maintenance cost per flight hour of the turboprop was 75% higher than that of the JT8D turbofan. Part of this difference was due to propeller and gearbox costs being higher than those of the fan and reverser, but most of the difference was in the engine core where the older technology turboprop core maintenance costs were nearly 70 percent higher than for the turbofan. The estimated maintenance cost of both the advanced turboprop and advanced turbofan were less than the JT8D. The conclusion was that an advanced turboprop and an advanced turbofan, using similar cores, will have very competitive maintenance costs per flight hour.

  19. Investigation of pressure drop in capillary tube for mixed refrigerant Joule-Thomson cryocooler

    SciTech Connect

    Ardhapurkar, P. M.; Sridharan, Arunkumar; Atrey, M. D.

    2014-01-29

    A capillary tube is commonly used in small capacity refrigeration and air-conditioning systems. It is also a preferred expansion device in mixed refrigerant Joule-Thomson (MR J-T) cryocoolers, since it is inexpensive and simple in configuration. However, the flow inside a capillary tube is complex, since flashing process that occurs in case of refrigeration and air-conditioning systems is metastable. A mixture of refrigerants such as nitrogen, methane, ethane, propane and iso-butane expands below its inversion temperature in the capillary tube of MR J-T cryocooler and reaches cryogenic temperature. The mass flow rate of refrigerant mixture circulating through capillary tube depends on the pressure difference across it. There are many empirical correlations which predict pressure drop across the capillary tube. However, they have not been tested for refrigerant mixtures and for operating conditions of the cryocooler. The present paper assesses the existing empirical correlations for predicting overall pressure drop across the capillary tube for the MR J-T cryocooler. The empirical correlations refer to homogeneous as well as separated flow models. Experiments are carried out to measure the overall pressure drop across the capillary tube for the cooler. Three different compositions of refrigerant mixture are used to study the pressure drop variations. The predicted overall pressure drop across the capillary tube is compared with the experimentally obtained value. The predictions obtained using homogeneous model show better match with the experimental results compared to separated flow models.

  1. Theoretical study of orbital ordering induced structural phase transition in iron pnictides

    NASA Astrophysics Data System (ADS)

    Jena, Sushree Sangita; Panda, S. K.; Rout, G. C.

    2016-05-01

    We attribute the structural phase transition (SPT) in the parent compounds of the iron pnictides to orbital ordering. Due to anisotropy of the dxz and dyz orbitals in the xy plane, orbital ordering makes the orthorhombic structure more favorable and thus inducing the SPT. We consider a one band model Hamiltonian consisting of first and second-nearest-neighbor hopping of the electrons. We introduce Jahn-Tellar (JT) distortion in the system arising due to the orbital ordering present in this system. We calculate the electron Green's function by using Zuvareb's Green's function technique and hence calculate an expression for the temperature dependent lattice strain which is computed numerically and self-consistently. The temperature dependent electron specific heat is calculated by minimizing the free energy of the system. The lattice strain is studied by varying the JT coupling and elastic constant of the system. The structural anomaly is studied through the electron occupation number and the specific heat by varying the physical parameters like JT coupling, lattice constant, chemical potential and hopping integrals of the system.

  2. Miniature Piezoelectric Compressor for Joule-Thomson Cryocoolers

    NASA Astrophysics Data System (ADS)

    Sobol, Sergey; Tzabar, Nir; Grossman, Gershon

    Joule-Thomson (JT) cryocoolers operate with a continuous flow of the working fluid that enters the cooler at a high pressure and leaves it at a lower pressure. Ideally, the temperature of the outgoing fluid equals the temperature of the entering fluid. JT cryocoolers that operate with pure refrigerants require high pressure of a few tens of MPa where the low pressure is usually around 0.1 MPa. Circulation of the working fluid in such cases requires high pressure ratio compressors that evidently have large dimensions. JT cryocoolers can operate with much lower pressure ratios by using mixed-refrigerants. Cooling from 300 K to about 80 K in a single stage cryocooler normally requires a pressure ratio of about 1:25. In the present research a miniature compressor driven by piezoelectric elements is developed in collaboration between Rafael and the Technion. This type of compressor has the advantage of improved long life compared to other mechanical compressors, very low vibrations, and silent operation. In the current case, the design goal of the intake and discharge pressures has been 0.1 and 2.5 MPa, respectively, with a flow rate of 0.06 g/s. The compressor has two compression stages; 1:5 and 5:25. Several configurations have been considered, fabricated, and tested. The performance of the last configuration approaches the desired specification and is presented in the current paper together with the design concept.

  3. Intermediate-coupling theory of the spin polaron in the t-J model

    NASA Astrophysics Data System (ADS)

    Barentzen, Heinz

    1996-03-01

    The spin polaron in the t-J model, i.e., a hole dressed by a cloud of virtual magnons of the antiferromagnetic spin background, is treated within the framework of intermediate-coupling theory. To this end the original t-J model is first reformulated in terms of spinless fermions and bosons by means of the generalized Dyson-Maleev representation (DMR). The latter may be regarded as the natural extension of the ordinary DMR of pure (undoped) spin systems to the case where holes are present, and is similar to the one originally proposed by Schmitt-Rink, Varma, and Ruckenstein. The reformulated t-J model, which is reminiscent of the Fröhlich Hamiltonian, is then subjected to a series of unitary transformations, analogous to those employed by Lee, Low, and Pines in their treatment of the Fröhlich polaron. Our approach yields an approximate quasiparticle energy E(k) as well as the corresponding eigenvector. To explore the range of validity of the theory presented here, the analytic expressions are then further analyzed for intermediate (J/t=0.4) and strong (J/t=0.08) coupling, where special attention is paid to the quasiparticle bandwidth W. The intermediate-coupling result for E(k) is in excellent agreement with the dispersion curve recently obtained by Dagotto and co-workers by means of a Green function Monte Carlo method. Surprisingly, even in the strong-coupling range the bandshape remains qualitatively correct. The bandwidth W is rather accurate for weak coupling (J/t>~3), as expected, and still reasonable in the intermediate range 0.4<~J/t<=3, where it deviates from the correct values by some 10-20 %. Our theory fails, however, to describe the proper behavior of W in the strong-coupling regime. This shows that the limitations of our approach manifest themselves in the bandwidths rather than in the shapes of the dispersion curves. Our conclusion is that intermediate-coupling theory is appropriate for J/t>~0.4, whereas a genuine strong-coupling theory is required

  4. Vibrational Jahn-Teller Effect in Non-Degenerate Electronic States

    NASA Astrophysics Data System (ADS)

    Dawadi, Mahesh B.; Thapaliya, Bishnu P.; Bhatta, Ram; Perry, David S.

    2015-06-01

    The Jahn-Teller theorem states that "All non-linear nuclear configurations are therefore unstable for an orbitally degenerate electronic state." In 1982, Kellman realized that the Jahn-Teller theorem also applies to nonlinear molecular species in non-degenerate electronic states when there are high-frequency vibrations that are degenerate at a symmetrical reference geometry. When those high frequencies can be considered as adiabatic functions of degenerate low-frequency coordinates, there is a spontaneous Jahn-Teller distortion that lifts the degeneracy of the high-frequency vibrations. Kellman applied the vibrational Jahn-Teller (vJT) concept to the Van der Waals dimer (SF6)2. In this talk, the vJT concept is applied to E ⊗ e systems that are small bound molecules in non-degenerate electronic states. The first case considered in systems for which the global minimum of the electronic potential has C3v symmetry.For such systems, including (C6H6)Cr(CO)3 and CH3CN, the vJT effect leads to a significant splitting of the degenerate high-frequency vibrations (CH or CO stretches), but the spontaneous vJT distortion is exceptionally small. The second case in systems for which the global minimum of the electronic potential is substantially distorted from the C3v reference geometry. For the second case systems, including CH3OH and CH3SH, the vJT splitting of the degenerate CH stretches is much larger, on the order of several 10Äôs of cm-1). For both cases, there is the symmetry-required vibrational conical intersection at the C3v reference geometry. For the second case systems, there are additional symmetry-allowed vibrational conical intersections far from the C3v geometry but energetically accessible to the molecule at thermal energies. For both cases, the vibrationally adiabatic surfaces, including the multiple conical intersections, are well described by modest extensions to a high-order Hamiltonian that was developed for the electronic Jahn-Teller problem. H

  5. Comparison of functional biochemical, and morphometric alterations in the lungs of four rat strains and hamsters following repeated intratracheal instillation of crocidolite asbestos

    EPA Science Inventory

    Four rat strains and hamsters were exposed to 0.7mg crocidolite asbestos/g lung once/wk for 3weeks by intratracheal instillation (IT). Pulmonary function, biochemistry, and morphometry were evaluated at 3 and 6-months after IT. Each rat strain, but not the hamster, exhibited ele...

  6. A TELL English Course to Meet the Needs of a Multilevel BA in ELT Group: What Was Wrong?

    ERIC Educational Resources Information Center

    Reyes Fierro, María del Carmen; Delgado Alvarado, Natanael

    2015-01-01

    A Technology Enhanced Language Learning (TELL) course was designed to meet the needs of a multilevel first-semester group of students of the BA in English Language Teaching (ELT) taught at the School of Languages of the Juarez University of the State of Durango (ELE-UJED), Mexico. Amongst the relevant needs, students were to reach a CEFR B1.1…

  7. Arsenic Removal from Drinking Water by Coagulation/Filtration, U.S. EPA Demonstration Project at the City of Okanogan, WA - Final Performance Evaluation Report

    EPA Science Inventory

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at the City of Okanogan, WA facility. The objectives of the project were to evaluate: (1) the effectiveness of Filtronics’ FH-13 Ele...

  8. Permeability barriers to embryo cryopreservation of Pectinophora gossypiella (Lepidoptera: Gelechiidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to develop a method to cryopreserve the embryos of the pink bollworm moth, Pectinophora gossypiella (Saunders). Previously developed dipteran cryopreservation protocols were not directly adaptable to use with the embryos of this lepidopteran species. Physiochemical and ele...

  9. EVALUATING THE EXTENT AND RELATIVE RISK OF AQUATIC STRESSORS IN WADEABLE STREAMS THROUGHOUT THE U.S.A.

    EPA Science Inventory

    Aquatic stressors such as toxic chemicals, excess sediment, and non-native species threaten the biointegrity of stream ecosystems. The relative importance of a stressor depends both on the number of streams in which it is elevated, and on the severity of its effect when it is ele...

  10. Use of Electrical Penetration Graph Technology to Examine Transmission of ‘Candidatus Liberibacter solanacearum’ to Potato by Three Haplotypes of Potato Psyllid (Bactericera cockerelli; Hemiptera: Triozidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), is a vector of the phloem-limited bacterium ‘Candidatus Liberibacter solanacearum’ (Lso), the putative causal agent of zebra chip disease of potato. Little is known about how potato psyllid transmits Lso to potato. We used ele...

  11. Thinking Allowed: Managing Innovation in English Language Education--A Research Agenda

    ERIC Educational Resources Information Center

    Waters, Alan

    2014-01-01

    In Waters (2009), the author attempted to capture the "state of the art" in theorising, practice, and research activity about the management of innovation in English language education (ELE). In this article, he reprises a number of areas in that review, to identify where the field would benefit from further enquiry about how to…

  12. The Great Outdoors and Beyond: Common Threads in Leadership Training on Land, in the Air, and in Space.

    ERIC Educational Resources Information Center

    Irwin, Cheryl; Phipps, Maurice

    For over 7 years, the Wilderness Education Association (WEA) and three universities have been using a systematic approach to leadership training in the outdoors: the experiential leadership education (ELE) method. The effectiveness of this approach was investigated by an aerospace expert interested in leadership training for isolated groups. A…

  13. Process for selecting NEAMS applications for access to Idaho National Laboratory high performance computing resources

    SciTech Connect

    Michael Pernice

    2010-09-01

    INL has agreed to provide participants in the Nuclear Energy Advanced Mod- eling and Simulation (NEAMS) program with access to its high performance computing (HPC) resources under sponsorship of the Enabling Computational Technologies (ECT) program element. This report documents the process used to select applications and the software stack in place at INL.

  14. Decontamination of fresh and fresh-cut fruits and vegetables with cold plasma technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of fresh and fresh-cut fruits and vegetables by foodborne pathogens has prompted research into novel interventions. Cold plasma is a nonthermal food processing technology which uses energetic, reactive gases to inactivate contaminating microbes. This flexible sanitizing method uses ele...

  15. Cold Plasma as a nonthermal food processing technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of fresh and fresh-cut fruits and vegetables by foodborne pathogens has prompted research into novel interventions. Cold plasma is a nonthermal food processing technology which uses energetic, reactive gases to inactivate contaminating microbes. This flexible sanitizing method uses ele...

  16. Open Source Procedure for Assessment of Loss using Global Earthquake Modelling software (OPAL)

    NASA Astrophysics Data System (ADS)

    Daniell, J. E.

    2011-07-01

    This paper provides a comparison between Earthquake Loss Estimation (ELE) software packages and their application using an "Open Source Procedure for Assessment of Loss using Global Earthquake Modelling software" (OPAL). The OPAL procedure was created to provide a framework for optimisation of a Global Earthquake Modelling process through: 1. overview of current and new components of earthquake loss assessment (vulnerability, hazard, exposure, specific cost, and technology); 2. preliminary research, acquisition, and familiarisation for available ELE software packages; 3. assessment of these software packages in order to identify the advantages and disadvantages of the ELE methods used; and 4. loss analysis for a deterministic earthquake (Mw = 7.2) for the Zeytinburnu district, Istanbul, Turkey, by applying 3 software packages (2 new and 1 existing): a modified displacement-based method based on DBELA (Displacement Based Earthquake Loss Assessment, Crowley et al., 2006), a capacity spectrum based method HAZUS (HAZards United States, FEMA, USA, 2003) and the Norwegian HAZUS-based SELENA (SEismic Loss EstimatioN using a logic tree Approach, Lindholm et al., 2007) software which was adapted for use in order to compare the different processes needed for the production of damage, economic, and social loss estimates. The modified DBELA procedure was found to be more computationally expensive, yet had less variability, indicating the need for multi-tier approaches to global earthquake loss estimation. Similar systems planning and ELE software produced through the OPAL procedure can be applied to worldwide applications, given exposure data.

  17. The OPAL Project: Open source Procedure for Assessment of Loss using Global Earthquake Modelling software

    NASA Astrophysics Data System (ADS)

    Daniell, James

    2010-05-01

    This paper provides a comparison between Earthquake Loss Estimation (ELE) software packages and their application using an "Open Source Procedure for Assessment of Loss using Global Earthquake Modelling software" (OPAL). The OPAL procedure has been developed to provide a framework for optimisation of a Global Earthquake Modelling process through: 1) Overview of current and new components of earthquake loss assessment (vulnerability, hazard, exposure, specific cost and technology); 2) Preliminary research, acquisition and familiarisation with all available ELE software packages; 3) Assessment of these 30+ software packages in order to identify the advantages and disadvantages of the ELE methods used; and 4) Loss analysis for a deterministic earthquake (Mw7.2) for the Zeytinburnu district, Istanbul, Turkey, by applying 3 software packages (2 new and 1 existing): a modified displacement-based method based on DBELA (Displacement Based Earthquake Loss Assessment), a capacity spectrum based method HAZUS (HAZards United States) and the Norwegian HAZUS-based SELENA (SEismic Loss EstimatioN using a logic tree Approach) software which was adapted for use in order to compare the different processes needed for the production of damage, economic and social loss estimates. The modified DBELA procedure was found to be more computationally expensive, yet had less variability, indicating the need for multi-tier approaches to global earthquake loss estimation. Similar systems planning and ELE software produced through the OPAL procedure can be applied to worldwide applications, given exposure data. Keywords: OPAL, displacement-based, DBELA, earthquake loss estimation, earthquake loss assessment, open source, HAZUS

  18. Hands-On Teaching and Entrepreneurship Development.

    ERIC Educational Resources Information Center

    da Silveira, Marcos Azevedo; da Silva, Mauro Schwanke; Kelber, Christian R.; de Freitas, Manuel R.

    This paper presents the experiment being conducted in the Electric Circuits II course (ELE1103) at PUC-Rio's Electrical Engineering Department since March 1997. This experiment was held in both the fall and the spring semesters of 1997. The basis for the experiment was concurrent teaching methodology, to which the principles of entrepreneurship…

  19. OIL FLY ASH AND VANADIUM DIMINISH NRAMP-2MRNA AND PROTEIN EXPRESSION IN HUMAN BRONCHIAL EPITHELIAL CELLS

    EPA Science Inventory

    The capacity of Nramp2 to transport iron and its ubiquitous expression make it a likely candidate for transferrin-independent uptake of iron in peripheral tissues. Airway epithelial cells increase both mRNA and expression of that isoform of Nramp-2 without an iron response ele...

  20. Integration of Environmental Education and Environmental Law Enforcement for Police Officers

    ERIC Educational Resources Information Center

    Bovornkijprasert, Sravoot; Rawang, Wee

    2016-01-01

    The purpose of this research was to establish an integrated model of environmental education (EE) and environmental law enforcement (ELE) to improve the efficiency of functional competency for police officers in Bangkok Metropolitan Police Division 9 (MBP Div. 9). The research design was mixed methods of quantitative and qualitative approaches…

  1. The Impact of Overseas Training on Curriculum Innovation and Change in English Language Education in Western China

    ERIC Educational Resources Information Center

    Li, Daguo; Edwards, Viv

    2013-01-01

    This article assesses the impact of a UK-based professional development programme on curriculum innovation and change in English Language Education (ELE) in Western China. Based on interviews, focus group discussions and observation of a total of 48 English teachers who had participated in an overseas professional development programme influenced…

  2. MARKAL SCENARIO ANALYSES OF TECHNOLOGY OPTIONS FOR THE ELECTRIC SECTOR: THE IMPACT ON AIR QUALITY

    EPA Science Inventory

    This report provides a general overview of EPA’s national MARKAL database and energy systems model and compares various scenarios to a business as usual baseline scenario. Under baseline assumptions, total electricity use increases 1.3% annually until 2030. Annual growth in ele...

  3. 77 FR 5253 - Agency Information Collection Request. 60-Day Public Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... methods compared to those of ELE. To answer key research questions, ASPE will draw on 5 primary data... children for health coverage, despite their different methods of assessing income or otherwise determining... costs that may have resulted. The evaluation also provides an opportunity to understand other methods...

  4. Evaluation of a mass flow sensor at a gin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of a system to optimize the cotton ginning process, a custom-built mass flow sensor was evaluated at USDA-ARS Cotton Ginning Research Unit at Stoneville, Mississippi. The mass flow sensor was fabricated based on the principle of the sensor patented by Thomasson and Sui. The optical and ele...

  5. Improving Electrical Engineering Education at the American University of Sharjah through Continuous Assessment

    ERIC Educational Resources Information Center

    Al-Nashash, Hasan; Khaliq, Abdul; Qaddoumi, Nasser; Al-Assaf, Yousef; Assaleh, Khaled; Dhaouadi, Rached; El-Tarhuni, Mohamed

    2009-01-01

    The electrical engineering (ELE) program at the American University of Sharjah (AUS) is designed to fulfill the ABET criteria. Several assessment tools are used to qualitatively and quantitatively measure the level of achievement of the program's educational objectives and outcomes. These tools include alumni, employer, and graduate advisor…

  6. Local structure study of disordered crystalline materials with the atomic pair distribution function method

    NASA Astrophysics Data System (ADS)

    Qiu, Xiangyun

    distortions. For example, in the updoped compound LaMnO3, the Jahn-Teller (JT) transition around 750 K is characterized as distorted (JT active) to undistorted MnO6 octahedra transition by the conventional crystallographic analysis. However, our PDF results show local MnO6 octahedral distortions persist above the JT transition, and it is their random orientations that make the existing local distortions invisible to average structure analysis. The nature of the JT transition around 750 K is orbital order to disorder. Our first local structure study of the high temperature rhombohedral phase (T ≥ 1010 K) additionally discovered the existence of locally JT distorted MnO6 octahedra. More significantly, the range of the orbital order in the high temperature dynamic-JT phases; estimated from the crossover from the local to the average structure, is around 16 A (˜four MnO6 octahedra), suggesting strong nearest neighbor JT anti-ferrodistortive coupling. In the bi-layered La0.92Sr 2.08Mn2O7, we found the shape of MnO6 octahedron changes from oblate (4 long, 2 short Mn-O bonds) to prolate (2 long, 4 short Mn-O bonds) as the material goes from type A anti-ferromagnetic to type CE charge ordered phase. This can be understood as the d x2-y2 to dx,y2-r2 orbital occupancy transition of the Mn3+ e g electrons. Evidences for nano-scale inhomogeneities in the Mn4+ rich region of La2-2xSr 1+2xMn2O7 (0.54 ≤ x ≤ 0.80) are also discussed.

  7. Tumor suppressor gene mutation in a patient with a history of hyperparathyroidism-jaw tumor syndrome and healed generalized osteitis fibrosa cystica: a case report and genetic pathophysiology review.

    PubMed

    Parfitt, Joshua; Harris, Malcolm; Wright, John M; Kalamchi, Sabah

    2015-01-01

    Hyperparathyroidism-jaw tumor (HPT-JT) was first observed by Jackson in 1958 in a family who exhibited hyperparathyroidism and recurrent pancreatitis. The author noticed the presence of jaw tumors in the affected family and reported them as fibrous dysplasia. However, it was not until 1990 that a familial variety of hyperparathyroidism with fibro-osseous jaw tumors was recognized as HPT-JT syndrome and reported as a clinically and genetically distinct syndrome. Hyperparathyroidism generally arises from glandular hyperplasia or parathyroid adenomas, with only about 1% of cases resulting from parathyroid carcinoma. However, parathyroid carcinoma develops in about 15% of HPT-JT patients. The true incidence of HPT-JT is unknown, although the prevalence of about 100 published cases suggests its rarity. Twenty percent of HPT-JT cases have renal hamartomas or tumors, and female patients with HPT-JT have been reported to have carcinoma of the uterus. This syndrome appears to arise from a variety of mutations that deactivate the tumor suppressor gene CDC73 (also known as HRPT2) and its production of the tumor suppressor protein parafibromin. Functional parafibromin has 531 amino acids, and mutations result in a short nonfunctional protein. CDC73 disorders exhibit dominant germline gene behavior, with varying degrees of penetration. In most cases an affected person has 1 parent with the condition, which raises the need for family investigation and genetic counseling. We report a case of HPT-JT syndrome in a male patient who presented to the local community hospital 6 years previously with a history of back pain. Investigations showed elevated serum parathyroid hormone and calcium levels, and a technetium 99m sestamibi parathyroid scan showed increased activity at the site of the lower left gland that proved to be a substernal parathyroid carcinoma. The patient's parathyroid hormone level dropped from 126 to 97 pg/mL at 5 minutes and was 65 pg/mL at 10 minutes after excision

  8. Effects of dynamic Jahn-Teller distortions by Raman spectroscopy in the layered CMR manganite La{sub 2{minus}2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7}, x = 0.36

    SciTech Connect

    Bordallo, H.N.; Argyriou, D.N.; Mitchell, J.F.; Strouse, G.F.

    1998-12-01

    The close interplay among charge, spin, and lattice degrees of freedom in the colossal magnetoresistive (CMR) manganite oxides is believed to play an important role in the transport mechanism in these itinerant ferromagnets. While the work on CMR materials has concentrated on the 3D perovskite manganites, the discovery of the layered compounds La{sub 2{minus}2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7} as another class of CMR oxides provides a rich opportunity to explore the relationship between structure and transport properties on varying length and time scales in reduced dimensions. The crystal structure of the layered CMR compounds La{sub 2{minus}2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7} is comprised of perovskite bilayers of corner-linked MnO{sub 6} octahedra forming infinite sheets. Doping of divalent cations such as Sr{sup 2+} gives rise to a mixed valent system were Jahn-Teller (JT) active Mn{sup 3+} and JT-inactive Mn{sup 4+} co-exist on the lattice. Among the current theoretical models of transport in the three-dimensional perovskite materials is the role of JT. This transport mechanism plays a fundamental role above the Curie temperature (T{sub c}). Indeed, localized lattice distortions have been observed experimentally above T{sub c} in the (La,Ca)MnO{sub 3} perovskite system. In this communication, the authors report resonant Raman spectroscopic measurements on a micro-crystalline sample of La{sub 1.28}Sr{sub 1.72}Mn{sub 2}O{sub 7} (x = 0.36). The measurements suggest discrete phonon modes for the Mn{sup 3+} and Mn{sup 4+} lattice sites, which may arise from either dynamic or static localization and the presence of Mn{sup 2+} defects in the lattice.

  9. Nonpercolative nature of the metal-insulator transition and persistence of local Jahn-Teller distortions in the rhombohedral regime of La1 -xCaxMnO3

    NASA Astrophysics Data System (ADS)

    Shatnawi, Mouath; Bozin, Emil S.; Mitchell, J. F.; Billinge, Simon J. L.

    2016-04-01

    Evolution of the average and local crystal structure of Ca-doped LaMnO3 has been studied across the metal to insulator (MI) and the orthorhombic to rhombohedral (OR) structural phase transitions over a broad temperature range for two Ca concentrations (x =0.18 ,0.22 ). Combined Rietveld and high real space resolution atomic pair distribution function (PDF) analysis of neutron total scattering data was carried out with aims of exploring the possibility of nanoscale phase separation (PS) in relation to MI transition, and charting the evolution of local Jahn-Teller (JT) distortion of MnO6 octahedra across the OR transition at TS˜720 K. The study utilized explicit two-phase PDF structural modeling, revealing that away from TMI there is no evidence for nanoscale phase coexistence. The local JT distortions disappear abruptly upon crossing into the metallic regime both with doping and temperature, with only a small temperature-independent signature of quenched disorder being observable at low temperature as compared to CaMnO3. The results hence do not support the percolative scenario for the MI transition in La1 -xCaxMnO3 based on PS, and question its ubiquity in the manganites. In contrast to LaMnO3 that exhibits long-range orbital correlations and sizable octahedral distortions at low temperature, the doped samples with compositions straddling the MI boundary exhibit correlations (in the insulating regime) limited to only ˜1 nm with observably smaller distortions. In the x =0.22 sample local JT distortions are found to persist across the OR transition and deep into the R phase (up to ˜1050 K), where they are crystallographically prohibited. Their magnitude and subnanometer spatial extent remain unchanged.

  10. Resonance Raman characterization of the radical anion and triplet states of zinc tetraphenylporphine

    SciTech Connect

    Reed, R.A.; Purrello, R.; Prendergast, K.; Spiro, T.G. )

    1991-11-28

    The photophysical properties of metalloporphyrins are important to a range of current research areas, ranging from solar energy conversion to photodynamic therapy. Resonance Raman (RR) spectra are reported for the anion radical and for the photoexcited triplet state of ZnTPP. RR spectra were obtained by excitation at 457.9 nm, at the anion absorption band maximum. Bands were assigned with the aid of pyrrole-d[sub 8] and phenyl-d[sub 20] isotopomers. The pattern of isotope shifts and polarizations was found to be quite similar to that of the neutral parent, ZnTPP. The frequency shift pattern is discussed in terms of the expectations for placing an electron in the e[sub g]* orbital, including the anticipated Jahn-Teller (J-T) effect. Although band overlaps make depolarization ratios difficult to quantitate, the [nu][sub 10] band is found to be essentially depolarized, indicating that the J-T effect is dynamic, rather than static in character, at least with respect to stretching of the C[sub a]C[sub m] bonds. The [nu][sub 2] and [nu][sub 10] downshifts are attributable to porphyrin core expansion upon reduction, but the [nu][sub 27] and [nu][sub 29] reductions are probably manifestations of the J-T effect. Triplet-state RR spectra were produced with 416-nm photolysis and 459-nm probe pulses (7 ns). The RR peaks were assigned via their polarizations and the d[sub 8] and d[sub 20] isotopomer shifts. The spectrum contains three strong bands of predominantly phenyl character. Their frequencies are unshifted relative to the ground state, implying negligible electronic involvement of the phenyl groups in the T[sub 1] state, but their enhancements indicate substantial involvement in the resonant T[sub n] state. This state is suggested to be produced by charge transfer from the porphyrin e[sub g]* to the phenyl [pi]* orbitals.

  11. Rotational stabilization of the resistive wall modes in tokamaks with a ferritic wall

    SciTech Connect

    Pustovitov, V. D.; Yanovskiy, V. V.

    2015-03-15

    The dynamics of the rotating resistive wall modes (RWMs) is analyzed in the presence of a uniform ferromagnetic resistive wall with μ{sup ^}≡μ/μ{sub 0}≤4 (μ is the wall magnetic permeability, and μ{sub 0} is the vacuum one). This mimics a possible arrangement in ITER with ferromagnetic steel in test blanket modules or in future experiments in JT-60SA tokamak [Y. Kamada, P. Barabaschi, S. Ishida, the JT-60SA Team, and JT-60SA Research Plan Contributors, Nucl. Fusion 53, 104010 (2013)]. The earlier studies predict that such a wall must provide a destabilizing influence on the plasma by reducing the beta limit and increasing the growth rates, compared to the reference case with μ{sup ^}=1. This is true for the locked modes, but the presented results show that the mode rotation changes the tendency to the opposite. At μ{sup ^}>1, the rotational stabilization related to the energy sink in the wall becomes even stronger than at μ{sup ^}=1, and this “external” effect develops at lower rotation frequency, estimated as several kHz at realistic conditions. The study is based on the cylindrical dispersion relation valid for arbitrary growth rates and frequencies. This relation is solved numerically, and the solutions are compared with analytical dependences obtained for slow (s/d{sub w}≫1) and fast (s/d{sub w}≪1) “ferromagnetic” rotating RWMs, where s is the skin depth and d{sub w} is the wall thickness. It is found that the standard thin-wall modeling becomes progressively less reliable at larger μ{sup ^}, and the wall should be treated as magnetically thick. The analysis is performed assuming only a linear plasma response to external perturbations without constraints on the plasma current and pressure profiles.

  12. A Kinematical Approach to Dark Energy Studies

    SciTech Connect

    Rapetti, David; Allen, Steven W.; Amin, Mustafa A.; Blandford, Roger D.; /KIPAC, Menlo Park

    2006-06-06

    We present and employ a new kinematical approach to cosmological ''dark energy'' studies. We construct models in terms of the dimensionless second and third derivatives of the scale factor a(t) with respect to cosmic time t, namely the present-day value of the deceleration parameter q{sub 0} and the cosmic jerk parameter, j(t). An elegant feature of this parameterization is that all {Lambda}CDM models have j(t) = 1 (constant), which facilitates simple tests for departures from the {Lambda}CDM paradigm. Applying our model to the three best available sets of redshift-independent distance measurements, from type Ia supernovae and X-ray cluster gas mass fraction measurements, we obtain clear statistical evidence for a late time transition from a decelerating to an accelerating phase. For a flat model with constant jerk, j(t) = j, we measure q{sub 0} = -0.81 {+-} 0.14 and j = 2.16{sub -0.75}{sup +0.81}, results that are consistent with {Lambda}CDM at about the 1{sigma} confidence level. A standard ''dynamical'' analysis of the same data, employing the Friedmann equations and modeling the dark energy as a fluid with an equation of state parameter, w (constant), gives {Omega}{sub m} = 0.306{sub -0.040}{sup +0.042} and w = -1.15{sub -0.18}{sup +0.14}, also consistent with {Lambda}CDM at about the 1{sigma} level. In comparison to dynamical analyses, the kinematical approach uses a different model set and employs a minimum of prior information, being independent of any particular gravity theory. The results obtained with this new approach therefore provide important additional information and we argue that both kinematical and dynamical techniques should be employed in future dark energy studies, where possible. Our results provide further interesting support for the concordance {Lambda}CDM paradigm.

  13. Zero Gravity Cryogenic Vent System Concepts for Upper Stages

    NASA Technical Reports Server (NTRS)

    Flachbart, Robin H.; Holt, James B.; Hastings, Leon J.

    2001-01-01

    The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space, and would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray-bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray-bar system consists of a recirculation pump, a parallel flow concentric tube heat exchanger, and a spray-bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses.

  14. Cutting efficiency of apical preparation using ultrasonic tips with microprojections: confocal laser scanning microscopy study

    PubMed Central

    Kwak, Sang-Won; Moon, Young-Mi; Yoo, Yeon-Jee; Baek, Seung-Ho; Lee, WooCheol

    2014-01-01

    Objectives The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. Materials and Methods The apical 3-mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. Results There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Conclusions Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency. PMID:25383346

  15. Development status of the mechanical cryocoolers for the Soft X-ray Spectrometer on board Astro-H

    NASA Astrophysics Data System (ADS)

    Sato, Yoichi; Sawada, Kenichiro; Shinozaki, Keisuke; Sugita, Hiroyuki; Nishibori, Toshiyuki; Sato, Ryota; Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Takei, Yoh; Goto, Ken; Nakagawa, Takao; Fujimoto, Ryuichi; Kikuchi, Kenichi; Murakami, Masahide; Tsunematsu, Shoji; Ootsuka, Kiyomi; Kanao, Kenichi; Narasaki, Katsuhiro

    2014-11-01

    Astro-H is the Japanese X-ray astronomy satellite to be launched in 2015. The Soft X-ray Spectrometer (SXS) on board Astro-H is a high energy resolution spectrometer utilizing an X-ray micro-calorimeter array, which is operated at 50 mK by the ADR with the 30 liter superfluid liquid helium. The mechanical cryocoolers, 4 K-class Joule Thomson (JT) cooler and 20 K-class double-staged Stirling (2ST) cooler, are key components of the SXS cooling system to extend the lifetime of LHe cryogen beyond 3 years as required. Higher reliability was therefore investigated with higher cooling capability based on the heritage of existing cryocoolers. As the task of assessing further reliability dealt with the pipe-choking phenomena by contaminant solidification of the on-orbit SMILES JT cryocooler, outgassing from materials and component parts used in the cryocoolers was measured quantitatively to verify the suppression of carbon dioxide gas by their storage process and predict the total accumulated carbon dioxide for long-term operation. A continuous running test to verify lifetime using the engineering model (EM) of the 4 K-JT cooler is underway, having operated for a total of 720 days as of June 2013 and showing no remarkable change in cooling performance. During the current development phase, prototype models (PM) of the cryocoolers were installed to the test SXS dewar (EM) to verify the overall cooling performance from room temperature to 50 mK. During the EM dewar test, the requirement to reduce the transmitted vibration from the 2ST cooler compressor was recognized as mitigating the thermal instability of the SXS microcalorimeter at 50 mK.

  16. Development of a sorption-based Joule-Thomson cooler for the METIS instrument on E-ELT

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Vermeer, C. H.; Holland, H. J.; Benthem, B.; ter Brake, H. J. M.

    2015-12-01

    METIS, the Mid-infrared E-ELT Imager and Spectrograph, is one of the proposed instruments for the European Extremely Large Telescope (E-ELT) that will cover the thermal/mid-infrared wavelength range from 3-14 m. Its detectors and optics require cryogenic cooling at four temperature levels, 8 K for the N-band detectors, 25 K for the N-band imager, 40 K for the L/M-band detectors and 70 K for the optics. To provide cooling below 70 K, a vibration-free cooling technology based on sorption coolers is developed at the University of Twente in collaboration with Airbus Defence and Space Netherlands B.V. (former Dutch Space B.V.). We propose a sorption-based cooler with three cascaded Joule-Thomson (JT) coolers of which the sorption compressors are all heat sunk at the 70 K platform. A helium-operated cooler is used to obtain the 8 K level with a cooling power of 0.4 W. Here, three pre-cooling stages are used at 40 K, 25 K and 15 K. The latter two levels are provided by a hydrogen-based cooler, whereas the 40 K level is realized by a neon-based sorption cooler. To validate the designs, three demonstrators were built and tested: 1. Full-scale 8 K helium JT cold stage; 2. Scaled helium sorption compressor; 3. Scaled 40 K neon sorption JT cooler. In this paper, we present the design of these demos. We discuss the experiment results obtained so far, the lessons that were learned from these demos and the future development towards a real METIS cooler.

  17. High Resolution Jet Cooled Cavity Ringdown Spectroscopy of the tilde{A} State 31_0 Band of the NO_3 Radical

    NASA Astrophysics Data System (ADS)

    Codd, Terrance J.; Roudjane, Mourad; Miller, Terry A.

    2012-06-01

    The 2E''tilde{A} state of NO_3 is doubly degenerate and is therefore subject to Jahn-Teller (JT) distortion. In the tilde{A} state there are two JT active modes, ν_3 and ν_4 (e' stretch and in plane bend respectively). Theoretical work has predicted that the JT effect in the tilde{A} state should be quite strong and approach the static case (D≥1) where the molecule is permanently distorted to a lower symmetry geometry. A moderate resolution spectrum of the tilde{A} state showed a feature that we tentatively assigned as the 31_0 band based on position and band contour. Using high resolution cavity ringdown spectroscopy we have now obtained a rotationally resolved spectrum of this band. The analysis of this band has been commenced using an oblate symmetric top Hamiltonian with spin-rotation terms. This analysis supports the assignment of this band to the a_1'' vibronic component of the 31_0 band. So far, the spectrum shows no evidence of a large geometric distortion of the molecule. Some lines appear to be split, as was previously observed in the 41_0 and 42_0 bands, and the possible sources of this splitting are being investigated. J.F. Stanton, 66th OSU International Symposium on Molecular Spectroscopy, The Ohio State University, Columbus Ohio, 2011, TJ-03 W. Eisfeld, K. Morokuma, J. Chem. Phys. 114, 9430 (2001) S. Faraji, H. Köppel, W. Eisfeld, S. Mahapatra, J. Chem. Phys. 347, 110 (2008) T.J. Codd, M.W. Chen, T.A. Miller, 66th OSU International Symposium on Molecular Spectroscopy, The Ohio State University, Columbus Ohio, 2011, TD-06 M.W. Chen, T.J. Codd, G. Just, T.A. Miller, OSU International Symposium on Molecular Spectroscopy, The Ohio State University, Columbus Ohio, 2011, TD-07

  18. Association between mitochondrial DNA haplogroup and myelodysplastic syndromes.

    PubMed

    Poynter, Jenny N; Richardson, Michaela; Langer, Erica; Hooten, Anthony J; Roesler, Michelle; Hirsch, Betsy; Nguyen, Phuong L; Cioc, Adina; Warlick, Erica; Ross, Julie A

    2016-09-01

    Polymorphisms in mitochondrial DNA (mtDNA) are used to group individuals into haplogroups reflecting human global migration and are associated with multiple diseases, including cancer. Here, we evaluate the association between mtDNA haplogroup and risk of myelodysplastic syndromes (MDS). Cases were identified by the Minnesota Cancer Surveillance System. Controls were identified through the Minnesota State driver's license/identification card list. Because haplogroup frequencies vary by race and ethnicity, we restricted analyses to non-Hispanic whites. We genotyped 15 mtSNPs that capture common European mitochondrial haplogroup variation. We used SAS v.9.3 (SAS Institute, Cary, NC) to calculate odds ratios (OR) and 95% confidence intervals (CI) overall and stratified by MDS subtype and IPSS-R risk category. We were able to classify 215 cases with confirmed MDS and 522 controls into one of the 11 common European haplogroups. Due to small sample sizes in some subgroups, we combined mt haplogroups into larger bins based on the haplogroup evolutionary tree, including HV (H + V), JT (J + T), IWX (I + W + X), UK (U + K), and Z for comparisons of cases and controls. Using haplogroup HV as the reference group, we found a statistically significant association between haplogroup JT and MDS (OR = 0.58, 95% CI 0.36, 0.92, P = 0.02). No statistically significant heterogeneity was observed in subgroup analyses. In this population-based study of MDS, we observed an association between mtDNA haplogroup JT and risk of MDS. While previously published studies provide biological plausibility for the observed association, further studies of the relationship between mtDNA variation and MDS are warranted in larger sample sizes. © 2016 Wiley Periodicals, Inc. PMID:27121678

  19. EPR, ENDOR, and Electronic Structure Studies of the Jahn–Teller Distortion in an FeV Nitride

    PubMed Central

    2015-01-01

    The recently synthesized and isolated low-coordinate FeV nitride complex has numerous implications as a model for high-oxidation states in biological and industrial systems. The trigonal [PhB(tBuIm)3FeV≡N]+ (where (PhB(tBuIm)3– = phenyltris(3-tert-butylimidazol-2-ylidene)), (1) low-spin d3 (S = 1/2) coordination compound is subject to a Jahn–Teller (JT) distortion of its doubly degenerate 2E ground state. The electronic structure of this complex is analyzed by a combination of extended versions of the formal two-orbital pseudo Jahn–Teller (PJT) treatment and of quantum chemical computations of the PJT effect. The formal treatment is extended to incorporate mixing of the two e orbital doublets (30%) that results from a lowering of the idealized molecular symmetry from D3h to C3v through strong “doming” of the Fe–C3 core. Correspondingly we introduce novel DFT/CASSCF computational methods in the computation of electronic structure, which reveal a quadratic JT distortion and significant e–e mixing, thus reaching a new level of synergism between computational and formal treatments. Hyperfine and quadrupole tensors are obtained by pulsed 35 GHz ENDOR measurements for the 14/15N-nitride and the 11B axial ligands, and spectra are obtained from the imidazole-2-ylidene 13C atoms that are not bound to Fe. Analysis of the nitride ENDOR tensors surprisingly reveals an essentially spherical nitride trianion bound to Fe, with negative spin density and minimal charge density anisotropy. The four-coordinate 11B, as expected, exhibits negligible bonding to Fe. A detailed analysis of the frontier orbitals provided by the electronic structure calculations provides insight into the reactivity of 1: JT-induced symmetry lowering provides an orbital selection mechanism for proton or H atom transfer reactivity. PMID:25137531

  20. QT Interval Derived Measurements in Patients with Cardiac Syndrome X Compared to Coronary Artery Disease

    PubMed Central

    Lutfi, Mohamed F.

    2016-01-01

    Previous studies assessing effect of ischemia on ventricular repolarization are mostly directed toward patients with coronary artery disease (CAD); however, similar reports on cardiac syndrome X (CSX) are scarce. Whether microvascular dysfunction of CSX and ischemia induced by CAD produce comparable effect on ventricular repolarization is unclear and deserve further studies. In the present study, ECG measures of ventricular repolarization were compared between CAD and CSX patients (40 subjects in each group). Following evaluation of sociodemographic characteristics, medical and past medical history, a resting ECG was used to assess measurements of ventricular repolarization in each patient, namely, QT interval (QT), corrected QT interval (QTc), QT dispersion (QTd), corrected QT dispersion (QTcd), adjacent QT dispersion (AdQTd), QT dispersion ratio (QTdR), JT dispersion (JTd), and Corrected JT dispersion (JTcd). Results showed comparable QT intervals and QTd in CAD and CSX patients even after adjustment for the possible variations in gender, age and body mass index of the studied groups. Although JTd was increased in CSX subjects (26.6 ± 7.2 ms) compared with CAD patients (22.7 ± 6.5 ms, p = 0.019), statistical significance disappeared after correcting JT for variations in heart rate. QT and QTc were significantly below 440 ms in CAD as well as CSX patients (p < 0.001). In contrast, maximum QTd, maximum QTcd and AdQTd of CAD and CSX patients were significantly above 440 ms (p < 0.001). The means of JTd and JTcd were significantly above 22 ms and 24 ms respectively (p < 0.001, p = 0.001) in CSX but not CAD patients (p = 0.529, p = 0.281). The present findings clearly demonstrate comparable measures of ventricular repolarization in CAD and CSX patients and consequently an equal risk of cardiac events in both groups. PMID:27708590