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Sample records for katrin jgar jt

  1. Status of the neutrino mass experiment KATRIN

    SciTech Connect

    Bornschein, L.; Bornschein, B.; Sturm, M.; Roellig, M.; Priester, F.

    2015-03-15

    The most sensitive way to determine the neutrino mass scale without further assumptions is to measure the shape of a tritium beta spectrum near its kinematic end-point. Tritium is the nucleus of choice because of its low endpoint energy, superallowed decay and simple atomic structure. Within an international collaboration the Karlsruhe Tritium Neutrino experiment (KATRIN) is currently being built up at KIT. KATRIN will allow a model-independent measurement of the neutrino mass scale with an expected sensitivity of 0.2 eV/c{sup 2} (90% CL). KATRIN will use a source of ultrapure molecular tritium. This contribution presents the status of the KATRIN experiment, thereby focusing on its Calibration and Monitoring System (CMS), which is the last component being subject to research/development. After a brief overview of the KATRIN experiment in Section II the CMS is introduced in Section III. In Section IV the Beta Induced X-Ray Spectroscopy (BIXS) as method of choice to monitor the tritium activity of the KATRIN source is described and first results are presented.

  2. Tritium processing loop for KATRIN experiment

    SciTech Connect

    Kazachenko, O.; Bornschein, B.; Kernert, N.; Doerr, L.; Glugla, M.; Weber, V.; Stern, D.

    2008-07-15

    The design of tritium processing loop for KATRIN tritium source supported by high purity of tritium has been demonstrated. The demonstration has showed tritium beta spectrum using a high energy resolution electrostatic spectrometer with adiabatic magnetic collimation. The demonstration proved that the systematic uncertainties in KATRIN can cause the use of a windowless gaseous tritium source (WGTS) as the main beta source. The tritium processing system (TPS) involves an inner loop providing the circulation of tritium through WGTS and control of isotope composition of the circulating gas. The demonstration compress and purify the pumped tritium by TPS and returned back to the source. The processing capability of the system in the demonstration kept on the level of 40 gram of tritium per day. The demonstration proved that the system can fulfil the requirements of KATRIN project with stable circulation of pure tritium. (authors)

  3. Status of the KATRIN Neutrino Mass Experiment

    NASA Astrophysics Data System (ADS)

    Parno, Diana; Katrin Collaboration

    2015-04-01

    The Karlsruhe Tritium Neutrino experiment (KATRIN), presently under construction in Germany, will probe the absolute mass scale of the neutrino through the kinematics of tritium beta decay, a nearly model-independent approach. To achieve the projected sensitivity of 0.2 eV at the 90% confidence level, KATRIN will use a windowless, gaseous tritium source and a large magnetic adiabatic collimation-electrostatic filter. The collaboration has now completed a second commissioning phase of the spectrometer and detector section, and construction of the tritium sections is proceeding well. We will report on the current status of the experiment and the outlook for data-taking with tritium. US participation in KATRIN is supported by the U.S. Department of Energy Office of Science, Office of Nuclear Physics under Award Number DE-FG02-97ER41020.

  4. The KATRIN neutrino mass experiment

    NASA Astrophysics Data System (ADS)

    Wolf, Joachim; Katrin Collaboration

    2010-11-01

    The Karlsruhe Tritium Neutrino experiment (KATRIN) aims to determine the electron neutrino mass from tritium decay in a model-independent way, by a kinematic measurement of the energy of ?-electrons. The unprecedented sensitivity of 0.2 eV/ c2 will improve present limits by one order of magnitude. The decay electrons will originate from a 10 m long windowless gaseous tritium source. Super-conducting magnets will guide the electrons through a differential and cryogenic pumping section to the electro-static tandem spectrometer (MAG-E-filter), where the kinetic energy will be measured. The experiment is presently being built at the Forschungszentrum Karlsruhe by an international collaboration of more than 120 scientists. The largest component, the 1240 m 3 main spectrometer, was delivered end of 2006 and first commissioning tests have been performed. This paper gives an overview of the goals and technological challenges of the experiment and reports on the progress in commissioning first major components. The start of first measurements is expected in 2012.

  5. Measurements with the KATRIN pre-spectrometer

    NASA Astrophysics Data System (ADS)

    Bornschein, L.; The Katrin Collaboration

    2006-07-01

    The objective of the KArlsruhe TRItium Neutrino experiment (KATRIN) is a direct measurement of the absolute mass of the electron (anti)neutrino by means of precise spectroscopy of the tritium ?-spectrum near its endpoint. The pre-spectrometer is part of the KATRIN reference set-up where it will work as a pre-filter for low energy ?-decay electrons that are inessential for the determination of the ?-mass. Since its delivery in autumn 2003 the pre-spectrometer has been the first major hardware component of KATRIN in operation at Forschungszentrum Karlsruhe (FZK). The vacuum measurements were successfully completed in early 2005. The main results are an outgassing rate for the stainless steel surface of the pre-spectrometer of 10 -12 mbar l/s cm 2 at room temperature and a final pressure below 10 -11 mbar. This corresponds to the specification of the main spectrometer. The amount of Non-Evaporable-Getter (NEG) strips needed can be restricted to about 3000 m and the additional cooling of the main spectrometer is optional, if a combined pumping system of NEG and turbo-molecular pumps (TMPs) is installed, that will provide a sufficient pumping speed. The modification of the pre-spectrometer set-up for the electromagnetic measurements is nearly completed, and the measurements will start in spring 2006.

  6. Measurements with the KATRIN pre-spectrometer

    NASA Astrophysics Data System (ADS)

    Habermehl, F.; KATRIN Collaboration

    2008-07-01

    The KArlsruhe TRItium Neutrino (KATRIN) experiment aims at directly measuring the anti-electron neutrino mass by investigating the kinematics of the tritium-? decay with a sensitivity of 0.2 eV/c2. The measurement set-up will comprise a windowless gaseous molecular tritium source, a differential and cryogenic pumped electron transport section, a tandem spectrometer system for the energy analysis, followed by a detector-system for counting transmitted ?-decay electrons [1][2]. The pre-spectrometer, being the first major component in operation, is used as a prototype for further investigation and validation of the vacuum concept as well as the novel electromagnetic design of the MAC-E filter. The test measurements presented here verify both vacuum concept and the electro-magnetic design.

  7. A mobile magnetic sensor unit for the KATRIN main spectrometer

    NASA Astrophysics Data System (ADS)

    Osipowicz, A.; Seller, W.; Letnev, J.; Marte, P.; Mller, A.; Spengler, A.; Unru, A.

    2012-06-01

    The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the electron neutrino mass with an unprecedented sensitivity of 0.2 eV/c2, using ? decay electrons from tritium decay. For the control of magnetic field in the main spectrometer area of the KATRIN experiment a mobile magnetic sensor unit is constructed and tested at the KATRIN main spectrometer site. The unit moves on inner rails of the support structures of the low field shaping coils which are arranged along the the main spectrometer. The unit propagates on a caterpillar drive and contains an electro motor, battery pack, board electronics, 2 triaxial flux gate sensors and 2 inclination senors. During operation all relevant data are stored on board and transmitted to the master station after the docking station is reached.

  8. Focal-plane detector system for the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Amsbaugh, J. F.; Barrett, J.; Beglarian, A.; Bergmann, T.; Bichsel, H.; Bodine, L. I.; Bonn, J.; Boyd, N. M.; Burritt, T. H.; Chaoui, Z.; Chilingaryan, S.; Corona, T. J.; Doe, P. J.; Dunmore, J. A.; Enomoto, S.; Formaggio, J. A.; Frnkle, F. M.; Furse, D.; Gemmeke, H.; Glck, F.; Harms, F.; Harper, G. C.; Hartmann, J.; Howe, M. A.; Kaboth, A.; Kelsey, J.; Knauer, M.; Kopmann, A.; Leber, M. L.; Martin, E. L.; Middleman, K. J.; Myers, A. W.; Oblath, N. S.; Parno, D. S.; Peterson, D. A.; Petzold, L.; Phillips, D. G.; Renschler, P.; Robertson, R. G. H.; Schwarz, J.; Steidl, M.; Tcherniakhovski, D.; Thmmler, T.; Van Wechel, T. D.; VanDevender, B. A.; Vcking, S.; Wall, B. L.; Wierman, K. L.; Wilkerson, J. F.; Wstling, S.

    2015-04-01

    The focal-plane detector system for the KArlsruhe TRItium Neutrino (KATRIN) experiment consists of a multi-pixel silicon p-i-n-diode array, custom readout electronics, two superconducting solenoid magnets, an ultra high-vacuum system, a high-vacuum system, calibration and monitoring devices, a scintillating veto, and a custom data-acquisition system. It is designed to detect the low-energy electrons selected by the KATRIN main spectrometer. We describe the system and summarize its performance after its final installation.

  9. Cryogenic Design of the Katrin Source Cryostat

    NASA Astrophysics Data System (ADS)

    Grohmann, S.; Bonn, J.; Bornschein, B.; Gehring, R.; Gil, W.; Kazachenko, O.; Neumann, H.; Noe, M.; Weiss, C.

    2008-03-01

    The KATRIN experiment will measure the mass of electron antineutrinos with a sensitivity of 0.2 eV/c2 by the precise measurement of the tritium ? spectrum. A key component is the Windowless Gaseous Tritium Source (WGTS), which will deliver 1011 ? decay electrons per second. The WGTS consists in its centre of a 10 m long beam tube operated at 30 K, which is surrounded by a series of superconducting solenoids. Molecular tritium is injected through a central injection chamber and pumped at either beam tube end. The tritium density profile must have a stability of 10-3 to limit systematic errors, yielding stringent requirements on the beam tube temperature homogeneity (30 mK) and stability (30 mK/h). This shall be achieved with a design, where the thermal radiation heat from the vacuum pumps is almost entirely absorbed by LN2 and He coolers on the pump ports, while the beam tube temperature is stabilized with saturated Ne in a thermosiphon. Starting from a functional description, we explain the cryogenic design of the magnet cryostat featuring 13 separate fluid circuits with 6 cryogenic fluids. Besides magnet cooling, we focus on the beam tube cooling and present the preparations for a full-scale demonstrator test.

  10. Small refrigerated J-T plants

    SciTech Connect

    Haws, R.

    1981-01-01

    The economic justification for building smaller natural gas liquids recovery plants has become a reality with the deregulated and decontrolled prices of gas liquids. Use of a Joule-Thomson (J-T) expansion valve to expand and cool compressed gas is discussed. Aspects of the process design, major equipment, instrumentation and electrification, field work, and approximate cost of J-T units are covered. The conclusion is that smaller modular designed cryogenic plants for natural gas liquids recovery are justified by use of a J-T expansion valve in lieu of a conventional expander unit.

  11. First tritium results of the KATRIN test experiment TRAP

    SciTech Connect

    Eichelhardt, F.; Bornschein, B.; Bornschein, L.; Kazachenko, O.; Kernert, N.; Sturm, M.

    2008-07-15

    The TRAP experiment (Tritium Argon frost Pump) has been built at the Tritium Laboratory Karlsruhe (TLK) as a test rig for the Cryogenic Pumping Section (CPS) of the Karlsruhe Tritium Neutrino Experiment (KATRIN). TRAP employs a heterogeneous layer of pre-condensed argon to adsorb hydrogen isotopes at {approx} 4.2 K This paper presents results obtained in the first three tritium experiments with TRAP. (authors)

  12. Radon induced background processes in the KATRIN pre-spectrometer

    NASA Astrophysics Data System (ADS)

    Frnkle, F. M.; Bornschein, L.; Drexlin, G.; Glck, F.; Grhardt, S.; Kfer, W.; Mertens, S.; Wandkowsky, N.; Wolf, J.

    2011-10-01

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale tritium ?-decay experiment to determine the effective electron anti-neutrino mass by investigating the kinematics of tritium ?-decay with a sensitivity of 200 meV/c 2 using the MAC-E filter technique. In order to reach this sensitivity, a low background level of 10 -2 counts per second (cps) is required. This paper describes how the decay of radon in a MAC-E filter generates background events, based on measurements performed at the KATRIN pre-spectrometer test setup. Radon (Rn) atoms, which emanate from materials inside the vacuum region of the KATRIN spectrometers, are able to penetrate deep into the magnetic flux tube so that the ?-decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn ?-decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. While low-energy electrons (<100 eV) directly contribute to the background in the signal region, higher energy electrons can be stored magnetically inside the volume of the spectrometer. Depending on their initial energy, they are able to create thousands of secondary electrons via subsequent ionization processes with residual gas molecules and, since the detector is not able to distinguish these secondary electrons from the signal electrons, an increased background rate over an extended period of time is generated.

  13. Development of the JT-60SA Neutral Beam Injectors

    SciTech Connect

    Hanada, M.; Kojima, A.; Inoue, T.; Watanabe, K.; Taniguchi, M.; Kashiwagi, M.; Tobari, H.; Umeda, N.; Akino, N.; Kazawa, M.; Oasa, K.; Komata, M.; Usui, K.; Mogaki, K.; Sasaki, S.; Kikuchi, K.; Nemoto, S.; Ohshima, K.; Endo, Y.; Simizu, T.

    2011-09-26

    This paper describes the development of the neutral beam (NB) systems on JT-60SA, where 30-34 MW D{sup 0} beams are required to be injected for 100 s. A 30 s operation of the NB injectors suggests that existing beamline components and positive ion sources on JT-60U can be reused without the modifications on JT-60 SA. The JT-60 negative ion source was modified to improve the voltage holding capability, which leads to a successful acceleration of 2.8 A H{sup -} ion beam up to 500 keV of the rated acceleration energy for JT-60SA.

  14. 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.

  15. Absolute neutrino mass scale determination with the KATRIN experiment

    SciTech Connect

    Glueck, F. |

    2007-10-12

    The aim of the KArlsruhe TRItium Neutrino experiment KATRIN is the direct and model independent determination of the absolute neutrino mass scale down to 0.2 eV. For this purpose, the integral electron energy spectrum will be measured close to the endpoint of molecular tritium beta decay. The electrostatic retardation method with magnetic adiabatic collimation (MAC-E filter) combines high energy resolution with high statistics and small background. The various components of the experiment (gaseous tritium source, pumping-transport system, pre- and main spectrometer, detector and rear system) are reviewed.

  16. 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.

  17. Gas and Pellet Injection Systems for JT-60 and JT-60U

    SciTech Connect

    Kizu, K.; Hiratsuka, H.; Miyo, Y.; Ichige, H.; Sasajima, T.; Nishiyama, T.; Masaki, K.; Honda, M.; Miya, N.; Hosogane, N.

    2002-09-15

    Designs and operations of the gas system and pellet injection systems for JT-60 and JT-60U are described. A gas injection valve that is a key component of the gas injection system was developed using a multilayer piezoelectric element. The maximum flow rate of this system is 43.3 Pa.m{sup 3}/s. The valve has mechanism for adjustment at atmospheric side meaning that a repair and an adjustment can be conducted without ventilation inside a vacuum vessel. It was confirmed that the effect of magnetic field and temperature change on the valves in the JT-60U environment was negligible.In JT-60U, two systems of pellet injector - a pneumatic drive and a centrifugal one - were developed. The pneumatic type attained a pellet velocity of 2.3 km/s, which was the world record at the time in 1988. On the other hand, the centrifugal one was developed in 1998. This injector can eject trains of up to 40 cubic (2.1 mm{sup 3}) pellets at frequencies of 1 to 10 Hz and speed of 0.1 to 1.0 km/s. A guide tube for a magnetic high field side injection (HFS) (top) was also developed in 1999. The pellet injection experiment with the HFS system started in 2000. In addition, another guide tube for HFS(mid) injection was newly developed and installed in March 2001. These systems are working well.

  18. Recent RF activities on JT-60U

    SciTech Connect

    Ikeda, Y.; Fujita, T.; Hamamatus, K.; Ide, S.; Imai, T.; Isayama, A.; Iwase, M.; Kasugai, A.; Kondoh, T.; Kusama, Y.; Moriyama, S.; Naito, O.; Nemoto, M.; Oikawa, T.; Sakamoto, K.; Seki, M.; Shinozaki, S.; Simono, M.; Takahashi, T.; Terakado, M.

    1999-09-20

    Recently, the JT-60U has employed ECRF system in addition to LHCD and ICRF systems. Three types of RF experiments on JT-60U have been performed. A reversed magnetic shear (R/S) configuration with internal transport barrier (ITB) was successfully maintained for 4.7 s in a quasi-steady state by LHCD in addition to the bootstrap current, where all profiles of temperature and plasma current were almost stationary. On the normal operation without heating during plasma current ramp-up, high electron temperature (T{sub e0}{approx}10 keV) with a strongly peaked profile was produced by LHCD alone at the density of {approx}0.5x10{sup 19} m{sup -3}. This peaked temperature profile was featured by a reduction in core density. The central electron temperature and density slowly changed in several seconds. The performances of ICRF (2{omega}{sub CH}) on the R/S configuration were also studied. Degradation of confinement of energetic particles was observed probably due to the large banana orbit loss. An 110 GHz ECRF system has been operated on JT-60U. Its gyrotron has successfully generated power at the level of up to 830 kW for 300 ms and is under conditioning. On the initial operation, the power of 620 kW was injected into plasmas. The central electron temperature increased from 3 keV to 5.5 keV at n{sub e}{approx}0.6x10{sup 19} m{sup -3}. A controllability of local heating was also demonstrated by the poloidally steerable mirror.

  19. 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.

  20. 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.

  1. Operation and Development on the Positive-Ion Based Neutral Beam Injection System for JT-60 and JT-60U

    SciTech Connect

    Kuriyama, M.; Akino, N.; Ebisawa, N.; Honda, A.; Itoh, T.; Kawai, M.; Mogaki, K.; Ohga, T.; Oohara, H.; Umeda, N.; Usui, K.; Yamamoto, M.; Yamamoto, T.; Matsuoka, M.

    2002-09-15

    The positive-ion based neutral beam injection (NBI) system for JT-60, which consists of 14 beamline units and has a beam energy of 70 to 100 keV, started operation in 1986 with hydrogen beams and injected a neutral beam power of 27 MW at 75 keV into the JT-60 plasma. In 1991, the NBI system was modified to be able to handle deuterium beams as part of the JT-60 upgrade modification. After executing some research and developments, deuterium beams of 40 MW at 95 keV were injected in 1996. As a result, NBI has contributed to the achievement of the highest performance plasmas, a DT-equivalent fusion power gain of 1.25 and a fusion triple product of 1.55 x 10{sup 21} keVs/m{sup 3}, in the world on JT-60U.

  2. The Cryogenic Pumping Section of KATRIN and the Test Experiment TRAP

    NASA Astrophysics Data System (ADS)

    Eichelhardt, F.; Katrin Collaboration

    2011-12-01

    The Karlsruhe Tritium Neutrino experiment (KATRIN) employs a Cryogenic Pumping Section (CPS) at ? 4.5 K to suppress the tritium penetration into the spectrometers. A test experiment (TRAP - Tritium Argon frost Pump) has been set up to investigate the tritium pumping performance of the CPS.

  3. Measurement and reduction of low-level radon background in the KATRIN experiment

    SciTech Connect

    Fränkle, F. M.

    2013-08-08

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale experiment to determine the mass of the electron anti-neutrino by investigating the kinematics of tritium beta decay with a sensitivity of 200 meV/c{sup 2}. The measurement setup consists of a high luminosity windowless gaseous molecular tritium source (WGTS), a differential and cryogenic pumped electron transport and tritium retention section, a tandem spectrometer section (pre-spectrometer and main spectrometer) for energy analysis, followed by a detector system for counting transmitted beta decay electrons. Measurements performed at the KATRIN pre-spectrometer test setup showed that the decay of radon (Rn) atoms in the volume of the KATRIN spectrometers is a major background source. Rn atoms from low-level radon emanation of materials inside the vacuum region of the KATRIN spectrometers are able to penetrate deep into the magnetic flux tube so that the alpha decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn alpha decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. Lowenergy electrons (< 100 eV) directly contribute to the background in the signal region. High-energy electrons can be stored magnetically inside the volume of the spectrometer and are able to create thousands of secondary electrons via subsequent ionization processes with residual gas molecules. In order to reduce the Rn induced background different active and passive counter measures were developed and tested. This proceeding will give an overview on Rn sources within the KATRIN spectrometer, describes how Rn decays inside the spectrometer produce background events at the detector and presents different counter measures to reduce the Rn induced background.

  4. Measurement and reduction of low-level radon background in the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Frnkle, F. M.

    2013-08-01

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale experiment to determine the mass of the electron anti-neutrino by investigating the kinematics of tritium beta decay with a sensitivity of 200 meV/c2. The measurement setup consists of a high luminosity windowless gaseous molecular tritium source (WGTS), a differential and cryogenic pumped electron transport and tritium retention section, a tandem spectrometer section (pre-spectrometer and main spectrometer) for energy analysis, followed by a detector system for counting transmitted beta decay electrons. Measurements performed at the KATRIN pre-spectrometer test setup showed that the decay of radon (Rn) atoms in the volume of the KATRIN spectrometers is a major background source. Rn atoms from low-level radon emanation of materials inside the vacuum region of the KATRIN spectrometers are able to penetrate deep into the magnetic flux tube so that the alpha decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn alpha decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. Lowenergy electrons (< 100 eV) directly contribute to the background in the signal region. High-energy electrons can be stored magnetically inside the volume of the spectrometer and are able to create thousands of secondary electrons via subsequent ionization processes with residual gas molecules. In order to reduce the Rn induced background different active and passive counter measures were developed and tested. This proceeding will give an overview on Rn sources within the KATRIN spectrometer, describes how Rn decays inside the spectrometer produce background events at the detector and presents different counter measures to reduce the Rn induced background.

  5. 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.

  6. A fast cool-down J-T minicryocooler

    NASA Astrophysics Data System (ADS)

    Xie, J. K.

    Design criteria for miniature open cycle Joule-Thomson (J-T) refrigerators were discussed by Geist and Lashmet (1960). Advantages of J-T minicryocoolers are related to compactness, low cost, and the ability to provide low temperatures very rapidly. Disadvantages include low efficiency and the requirement of a high-pressure gas source. The present investigation is concerned with a J-T minicryocooler which makes it possible to reach low temperatures very rapidly. The considered device has special design features, including a two-phase valve, a directly-wound fin tube, and a special combination of three heat exchangers. Attention is given to the thermodynamic cycle, a new heat exchanger for improving the capacity of minicryocoolers, and test data.

  7. Dynamic design of gas sorption J-T refrigerator

    NASA Astrophysics Data System (ADS)

    Chan, C. K.

    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.

  8. Performance verification tests of JT-60SA CS model coil

    NASA Astrophysics Data System (ADS)

    Obana, Tetsuhiro; Murakami, Haruyuki; Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku; Kizu, Kaname; Natsume, Kyohei; Yoshida, Kiyoshi

    2015-11-01

    As a final check of the coil manufacturing method of the JT-60 Super Advanced (JT-60SA) central solenoid (CS), we verified the performance of a CS model coil. The model coil comprised a quad-pancake wound with a Nb3Sn cable-in-conduit conductor. Measurements of the critical current, joint resistance, pressure drop, and magnetic field were conducted in the verification tests. In the critical-current measurement, the critical current of the model coil coincided with the estimation derived from a strain of -0.62% for the Nb3Sn strands. As a result, critical-current degradation caused by the coil manufacturing process was not observed. The results of the performance verification tests indicate that the model coil met the design requirements. Consequently, the manufacturing process of the JT-60SA CS was established.

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

    PubMed

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

    2015-08-01

    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. PMID:26329196

  10. 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.

  11. Neutrinos secretly converting to lighter particles to please both KATRIN and the cosmos

    NASA Astrophysics Data System (ADS)

    Farzan, Yasaman; Hannestad, Steen

    2016-02-01

    Within the framework of the Standard Model of particle physics and standard cosmology, observations of the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO) set stringent bounds on the sum of the masses of neutrinos. If these bounds are satisfied, the upcoming KATRIN experiment which is designed to probe neutrino mass down to ~ 0.2 eV will observe only a null signal. We show that the bounds can be relaxed by introducing new interactions for the massive active neutrinos, making neutrino masses in the range observable by KATRIN compatible with cosmological bounds. Within this scenario, neutrinos convert to new stable light particles by resonant production of intermediate states around a temperature of T~ keV in the early Universe, leading to a much less pronounced suppression of density fluctuations compared to the standard model.

  12. Tests of by-pass diodes at cryogenic temperatures for the KATRIN magnets

    SciTech Connect

    Gil, W.; Bolz, H.; Jansen, A.; Müller, K.; Steidl, M.; Hagedorn, D.

    2014-01-27

    The Karlsruhe Tritium Neutrino experiment (KATRIN) requires a series of superconducting solenoid magnets for guiding beta-electrons from the source to the detector. By-pass diodes will operate at liquid helium temperatures to protect the superconducting magnets and bus bars in case of quenches. The operation conditions of the by-pass diodes depend on the different magnet systems of KATRIN. Therefore, different diode stacks are designed with adequate copper heat sinks assuming adiabatic conditions. The by-pass diode stacks have been submitted to cold tests both at liquid nitrogen and liquid helium temperatures for checking operation conditions. This report presents the test set up and first results of the diode characteristics at 300 K and 77 K, as well as of endurance tests of the diode stacks at constant current load at 77 K and 4.2 K.

  13. 1450 m^3 at 10^-9 Pa: One of the KATRIN Challenges

    SciTech Connect

    Christian Day; R. Gumbsheimer; W. Herz; J. Wolf; J. Bonn; R. Reid; G.R. Myneni

    2006-11-12

    The KATRIN project is a challenging experiment to measure the mass of the electron neutrino directly with a sensitivity of 0.2 eV. It is a next generation tritium beta-decay experiment scaling up the size and precision of previous experiments by an order of magnitude as well as the intensity of the tritium beta source. Ultrafine spectrometric analysis of the energy distribution of the decay electrons at their very endpoint of 18.57 keV is the key to derive the neutrino mass. This is provided by a high-resolution spectrometer of unique size (10 m in diameter, 22 m in length). To avoid any negative influence from residual gas, the spectrometer vessel is designed to UHV/XHV conditions (an ultimate total pressure of below 10{sup -9} Pa and a wall outgassing rate below 10{sup -13} Pam{sup 3}/scm{sup 2}). The paper shortly describes the experimental idea behind KATRIN. The emphasis will then be given to the pumping concept for how to achieve the target parameters and to the manufacturing of the spectrometer tank. Critical issues will also be discussed (surface treatment, welding, transportation). Finally, a description of the current status and an outlook on the overall KATRIN schedule completes the paper.

  14. Advances in JT-60U facilities and its operation

    SciTech Connect

    Kimura, T.

    1995-12-31

    Recent advances in the JT-60 upgrade (JT-60U) facilities are described which have been made for supporting various physics programs aiming at obtaining reactor-grade plasmas with higher performance in quasi-steady state. It has been proved that B{sub 4}C-converted carbon fiber composite (CFC) graphite divertor tiles and decaborane-based boronization using a mixture of deuterium and helium as working gas of glow discharge are effective for wall conditioning. For improving the confinement and edge plasma characteristics, the operation of divertor plasmas with a shape of high triangularity in excess of 0.4 has been started. Feedback control of neutron production by NBI injection has been demonstrated for establishment of advanced plasma control in the steady state operation. With regard to the heating systems, the increase in the NBI beam power up to 36 MW has accelerated the progress in the JT-60U plasma performance and the increase in the ICRF power up to 6.4 MW has progressed the studies on fast ion behavior, especially the TAE mode since 1994. Although ten years passed since the first plasma of the JT-60, the integrity of its main facilities has been kept by right maintenance activities. Two important developments of a negative-ion-based NBI system with beam energy of 500 keV and injection power of 10 MW and an advanced closed pumped divertor are now in progress towards the steady-state operation with high performance.

  15. Development of JT-60SA superconducting magnet system

    NASA Astrophysics Data System (ADS)

    Yoshida, K.; Tsuchiya, K.; Kizu, K.; Murakami, H.; Kamiya, K.; Obana, T.; Takahata, K.; Peyrot, M.; Barabaschi, P.

    2010-11-01

    The upgrade of JT-60U magnet system to superconducting coils (JT-60SA) is progressing by both parties of Japanese government and European commission in the framework of the Broader Approach agreement. The magnet system for JT-60SA consists of 18 Toroidal Field (TF) coils, a Central Solenoid (CS) with four modules, six Equilibrium Field (EF) coils. The TF coil case encloses the winding pack and is the main structural component of the magnet system. The CS consists of four independent winding pack modules, which is support from the bottom of the TF coils. The six EF coils are attached to the TF coil cases through supports with flexible plates allowing radial displacements. The construction of CS and EF coils was started in 2008 by Japan Atomic Energy Agency (JAEA). The construction of TF coils will be started in 2009 by Fusion for Energy and European voluntary contributors. This paper introduces the design of the JT-60SA superconducting magnet system and activities for development of magnet components in Japan.

  16. JT-60U high performance regimes

    NASA Astrophysics Data System (ADS)

    Ishida, S.; JT-60 Team

    1999-09-01

    High performance regimes of JT-60U plasmas are presented with an emphasis upon the results from the use of a semiclosed pumped divertor with a W shaped geometry. Plasma performance in transient and quasi-steady states has been significantly improved in reversed shear and high ?p regimes. The reversed shear regime elevated an equivalent QeqDT transiently up to 1.25 (nD(0) ?ETi(0) = 8.6 1020m-3skeV) in a reactor relevant thermonuclear dominant regime. Long sustainment of enhanced confinement with internal transport barriers (ITBs) with fully non-inductive current drive in a reversed shear discharge was successfully demonstrated with LH wave injection. Performance sustainment has been extended in the high ?p regime with high triangularity, achieving a long sustainment of plasma conditions equivalent to QeqDT approx 0.16 (nD(0) ?ETi(0) approx 1.4 1020 m-3skeV) for ~4.5 s with a large non-inductive current drive fraction of 60-70% of the plasma current. Thermal and particle transport analyses show significant reduction of thermal and particle diffusivities around the ITB, resulting in a strong Er shear in the ITB region. The W shaped divertor is effective for helium ash exhaust, demonstrating a steady exhaust capability of ?*He/?E approx 3-10, which is favourable for ITER. Suppression of neutral backflow and chemical sputtering effects has been observed, while MARFE onset density is rather decreased. Negative ion based neutral beam injection (N-NBI) experiments have created a clear H mode transition. An enhanced ionization cross-section due to multistep ionization processes was confirmed as theoretically predicted. A current density profile driven by N-NBI is measured in good agreement with the theoretical prediction. N-NBI induced TAEs characterized as persistent and bursting oscillations have been observed from a low hot ? of langle?hrangle approx 0.1-0.2% without a significant loss of fast ions.

  17. Application of J-T plants for LP-gas recovery

    SciTech Connect

    Crum, F.S.

    1981-01-01

    The paper describes the J-T (Joule-Thomson) process that consists of the adiabatic expansion of a gas through a choke or valve from a high pressure to a low pressure. Various applications of the J-T process in oil and gas production are discussed with emphasis on LPG recovery. It is shown that J-T plants offer an attractive alternative to the turboexpander and refrigeration processes for certain applications.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Conceptual design of the JT-60SA cryogenic system

    NASA Astrophysics Data System (ADS)

    Lamaison, V.; Beauvisage, J.; Fejoz, P.; Girard, S.; Gonvalves, R.; Gond, R.; Heloin, V.; Michel, F.; Hoa, C.; Kamiya, K.; Roussel, P.; Vallet, J.-C.; Wanner, M.; Yoshida, K.

    2014-01-01

    The superconducting tokamak JT-60 Super Advanced (JT-60SA) is part of the Broader Approach Programme agreed between Europe and Japan. Among other in kind contributions, CEA is in charge of supplying the Cryogenic System which includes a Warm Compression Station, the Refrigerator Cold Box, the Auxiliary Cold Box, a compressed air station and the vacuum systems. The cryogenic system requires a refrigeration capacity of about 8 kW equivalent at 4.5 K. It will 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 between 80 K and 100 K. The contract for design, manufacture, installation and commissioning was signed between CEA and Air Liquide Advanced Technologies (AL-AT) in November 2012. The Cryogenic System shall be operational in 2016. The paper presents the main technical requirements and the limit of supply, the description of the process proposed by AL-AT, the main components, the preliminary layout and the interfaces at the JT-60SA Naka site.

  3. 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.

  4. Simulation of background from low-level tritium and radon emanation in the KATRIN spectrometers

    SciTech Connect

    Leiber, B.; Collaboration: KATRIN Collaboration

    2013-08-08

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a large-scale experiment for the model independent determination of the mass of electron anti-neutrinos with a sensitivity of 200 meV/c{sup 2}. It investigates the kinematics of electrons from tritium beta decay close to the endpoint of the energy spectrum at 18.6 keV. To achieve a good signal to background ratio at the endpoint, a low background rate below 10{sup −2} counts per second is required. The KATRIN setup thus consists of a high luminosity windowless gaseous tritium source (WGTS), a magnetic electron transport system with differential and cryogenic pumping for tritium retention, and electro-static retarding spectrometers (pre-spectrometer and main spectrometer) for energy analysis, followed by a segmented detector system for counting transmitted beta-electrons. A major source of background comes from magnetically trapped electrons in the main spectrometer (vacuum vessel: 1240 m{sup 3}, 10{sup −11} mbar) produced by nuclear decays in the magnetic flux tube of the spectrometer. Major contributions are expected from short-lived radon isotopes and tritium. Primary electrons, originating from these decays, can be trapped for hours, until having lost almost all their energy through inelastic scattering on residual gas particles. Depending on the initial energy of the primary electron, up to hundreds of low energetic secondary electrons can be produced. Leaving the spectrometer, these electrons will contribute to the background rate. This contribution describes results from simulations for the various background sources. Decays of {sup 219}Rn, emanating from the main vacuum pump, and tritium from the WGTS that reaches the spectrometers are expected to account for most of the background. As a result of the radon alpha decay, electrons are emitted through various processes, such as shake-off, internal conversion and the Auger deexcitations. The corresponding simulations were done using the KASSIOPEIA framework, which has been developed for the KATRIN experiment for low-energy electron tracking, field calculation and detector simulation. The results of the simulations have been used to optimize the design parameters of the vacuum system with regard to radon emanation and tritium pumping, in order to reach the stringent requirements of the neutrino mass measurement.

  5. Simulation of background from low-level tritium and radon emanation in the KATRIN spectrometers

    NASA Astrophysics Data System (ADS)

    Leiber, B.; Katrin Collaboration

    2013-08-01

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a large-scale experiment for the model independent determination of the mass of electron anti-neutrinos with a sensitivity of 200 meV/c2. It investigates the kinematics of electrons from tritium beta decay close to the endpoint of the energy spectrum at 18.6 keV. To achieve a good signal to background ratio at the endpoint, a low background rate below 10-2 counts per second is required. The KATRIN setup thus consists of a high luminosity windowless gaseous tritium source (WGTS), a magnetic electron transport system with differential and cryogenic pumping for tritium retention, and electro-static retarding spectrometers (pre-spectrometer and main spectrometer) for energy analysis, followed by a segmented detector system for counting transmitted beta-electrons. A major source of background comes from magnetically trapped electrons in the main spectrometer (vacuum vessel: 1240 m3, 10-11 mbar) produced by nuclear decays in the magnetic flux tube of the spectrometer. Major contributions are expected from short-lived radon isotopes and tritium. Primary electrons, originating from these decays, can be trapped for hours, until having lost almost all their energy through inelastic scattering on residual gas particles. Depending on the initial energy of the primary electron, up to hundreds of low energetic secondary electrons can be produced. Leaving the spectrometer, these electrons will contribute to the background rate. This contribution describes results from simulations for the various background sources. Decays of 219Rn, emanating from the main vacuum pump, and tritium from the WGTS that reaches the spectrometers are expected to account for most of the background. As a result of the radon alpha decay, electrons are emitted through various processes, such as shake-off, internal conversion and the Auger deexcitations. The corresponding simulations were done using the KASSIOPEIA framework, which has been developed for the KATRIN experiment for low-energy electron tracking, field calculation and detector simulation. The results of the simulations have been used to optimize the design parameters of the vacuum system with regard to radon emanation and tritium pumping, in order to reach the stringent requirements of the neutrino mass measurement.

  6. Nonlocal energetic particle mode in a JT-60U plasma

    NASA Astrophysics Data System (ADS)

    Todo, Y.; Shinohara, K.; Takechi, M.; Ishikawa, M.

    2005-01-01

    Energetic-ion driven instability in a Japan Atomic Energy Research Institute Tokamak-60 Upgrade (JT-60U) [S. Ishida et al., Phys. Plasmas 11, 2532 (2004)] plasma was investigated using a simulation code for magnetohydrodynamics and energetic particles. The spatial profile of the unstable mode peaks near the plasma center where the safety factor profile is flat. The unstable mode is not a toroidal Alfvn eigenmode (TAE) because the spatial profile deviates from the expected location of TAE and the spatial profile consists of a single primary harmonic m /n=2/1 where m and n are poloidal and toroidal mode numbers. The real frequency of the unstable mode is close to the experimental starting frequency of the fast frequency sweeping mode. Simulation results demonstrate that energetic-ion orbit width and energetic-ion pressure significantly broaden radial profile of the unstable mode. For the smallest value among the investigated energetic-ion orbit width, the unstable mode is localized within 20% of the minor radius. This gives an upper limit of the spatial profile width of the unstable mode which the magnetohydrodynamic effects alone can induce. For the experimental condition of the JT-60U plasma, energetic ions broaden the radial width of the unstable mode spatial profile by a factor of 3. The unstable mode is primarily induced by the energetic particles.

  7. High-voltage monitoring with a solenoid retarding spectrometer at the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Erhard, M.; Bauer, S.; Beglarian, A.; Bergmann, T.; Bonn, J.; Drexlin, G.; Goullon, J.; Groh, S.; Glck, F.; Kleesiek, M.; Haumann, N.; Hhn, T.; Johnston, K.; Kraus, M.; Reich, J.; Rest, O.; Schlsser, K.; Schupp, M.; Slezk, M.; Thmmler, T.; Vnos, D.; Weinheimer, C.; Wstling, S.; Zbo?il, M.

    2014-06-01

    The KATRIN experiment will measure the absolute mass scale of neutrinos with a sensitivity of m? = 200meV/c2 by means of an electrostatic spectrometer set close to the tritium ?-decay endpoint at 18.6keV. Fluctuations of the energy scale must be under control within 60mV (3ppm). Since a precise voltage measurement in the range of tens of kV is on the edge of current technology, a nuclear standard will be deployed additionally. Parallel to the main spectrometer the same retarding potential will be applied to the monitor spectrometer to measure 17.8-keV K-conversion electrons of 83mKr. This article describes the setup of the monitor spectrometer and presents its first measurement results.

  8. Status of the KATRIN Experiment and Prospects to Search for keV-mass Sterile Neutrinos in Tritium ?-decay

    NASA Astrophysics Data System (ADS)

    Mertens, Susanne

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single ?-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer's basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high source luminosity, a statistical sensitivity down to active-sterile mixing angles of sin2? < 1 . 10-7 (90% CL) could be reached.

  9. 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.

  10. Two-phase coexistence analysis of the bellows control mechanism for a J-T cryocooler

    NASA Astrophysics Data System (ADS)

    Chien, S. B.; Chen, L. T.

    1999-07-01

    The bellows control mechanism is one of the most critical control elements in the Joule-Thomson cryocooler. In the cool-down process, the interior gas of the bellows may reach liquefaction temperature, cause vapour-liquid two phase coexistence phenomena, and achieve the quick open/close control function of a J-T valve. This paper establishes a transient model of a simplified bellows mechanism, investigates the variation of the state properties of nitrogen inside the bellows, and its effects on the performance with different bellows stiffness in the cool-down process. According to the real shape and dimension, the two-phase model is put into a J-T cryocooler integrated model to accomplish the J-T cryocooler system simulation. To adopt the benefit of two-phase coexistence behavior effectively, a revised initial J-T valve design is also proposed in this work.

  11. Combined Brayton-JT cycles with refrigerants for natural gas liquefaction

    NASA Astrophysics Data System (ADS)

    Chang, Ho-Myung; Park, Jae Hoon; Lee, Sanggyu; Choe, Kun Hyung

    2012-06-01

    Thermodynamic cycles for natural gas liquefaction with single-component refrigerants are investigated under a governmental project in Korea, aiming at new processes to meet the requirements on high efficiency, large capacity, and simple equipment. Based upon the optimization theory recently published by the present authors, it is proposed to replace the methane-JT cycle in conventional cascade process with a nitrogen-Brayton cycle. A variety of systems to combine nitrogen-Brayton, ethane-JT and propane-JT cycles are simulated with Aspen HYSYS and quantitatively compared in terms of thermodynamic efficiency, flow rate of refrigerants, and estimated size of heat exchangers. A specific Brayton-JT cycle is suggested with detailed thermodynamic data for further process development. The suggested cycle is expected to be more efficient and simpler than the existing cascade process, while still taking advantage of easy and robust operation with single-component refrigerants.

  12. Initial Boronization of JT-60U Tokamak Using Decaborane

    NASA Astrophysics Data System (ADS)

    Saidoh, Masahiro; Ogiwara, Norio; Shimada, Michiya; Arai, Takashi; Hiratsuka, Hajime; Koike, Tsuneyuki; Shimizu, Masatsugu; Ninomiya, Hiromasa; Nakamura, Hiroo; Jimbou, Ryutarou; Yagyu, Jyunichi; Sugie, Tatsuo; Sakasai, Akira; Asakura, Nobuyuki; Yamage, Masashi; Sugai, Hideo; Jackson, Gary L.

    1993-07-01

    A decaborane-based boronization system has been installed in the JT-60U tokamak in order to reduce the influx of impurities during plasma discharges. Boronization has been performed under a glow discharge using a helium-decaborane gas mixture. The properties of the boron films deposited through boronization and the effects of boronization on the tokamak discharges were investigated. It was found that the deposition of a boron layer with high purity was achieved with few impurities other than hydrogen through boronization, and that the present boronization deposited toroidally nonuniform boron film. It was also found that the decaborane-based boronization resulted in good plasma performance similar to that of conventional boronization.

  13. Initial boronization of JT-60U tokamak using decaborane

    NASA Astrophysics Data System (ADS)

    Saidoh, Masahiro; Ogiwara, Norio; Shimada, Michiya; Arai, Takashi; Hiratsuka, Hajime; Koike, Tsuneyuki; Shimizu, Masatsugu; Ninomiya, Hiromasa; Nakamura, Hiroo; Jimbou, Ryutarou

    1993-07-01

    A decaborane-based boronization system has been installed in the JT-60U tokamak in order to reduce the influx of impurities during plasma discharges. Boronization has been performed under a glow discharge using a helium-decaborane gas mixture. The properties of the boron films deposited through boronization and the effects of boronization on the tokamak discharges were investigated. It was found that the deposition of a boron layer with high purity was achieved with few impurities other than hydrogen through boronization and that the present boronization deposited toroidally nonuniform boron film. It was also found that the decaborane-based boronization resulted in good plasma performance similar to that of conventional boronization.

  14. 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.

  15. Miniature Joule Thomson (JT) CryoCoolers for Propellant Management

    NASA Technical Reports Server (NTRS)

    Kapat, Jay; Chow, Louis

    2002-01-01

    A proof-of-concept project is proposed here that would attempt to demonstrate how miniature cryocoolers can be used to chill the vacuum jacket line of a propellant transfer line and thus to achieve transfer line pre-chill, zero boil off and possible propellant densification. The project would be performed both at UCF and KSC, with all of the cryogenic testing taking place in the KSC cryogenic test bed. A LN2 line available in that KSC test facility would serve to simulate a LOX transfer line. Under this project, miniature and highly efficient cold heads would be designed. Two identical cold heads will be fabricated and then integrated with a JT-type cryogenic system (consisting of a common compressor and a common external heat exchanger). The two cold heads will be integrated into the vacuum jacket of a LN2 line in the KSC cryo lab, where the testing will take place.

  16. Advanced tokamak research with integrated modeling in JT-60 Upgradea)

    NASA Astrophysics Data System (ADS)

    Hayashi, N.; JT-60 Team

    2010-05-01

    Researches on advanced tokamak (AT) have progressed with integrated modeling in JT-60 Upgrade [N. Oyama et al., Nucl. Fusion 49, 104007 (2009)]. Based on JT-60U experimental analyses and first principle simulations, new models were developed and integrated into core, rotation, edge/pedestal, and scrape-off-layer (SOL)/divertor codes. The integrated models clarified complex and autonomous features in AT. An integrated core model was implemented to take account of an anomalous radial transport of alpha particles caused by Alfven eigenmodes. It showed the reduction in the fusion gain by the anomalous radial transport and further escape of alpha particles. Integrated rotation model showed mechanisms of rotation driven by the magnetic-field-ripple loss of fast ions and the charge separation due to fast-ion drift. An inward pinch model of high-Z impurity due to the atomic process was developed and indicated that the pinch velocity increases with the toroidal rotation. Integrated edge/pedestal model clarified causes of collisionality dependence of energy loss due to the edge localized mode and the enhancement of energy loss by steepening a core pressure gradient just inside the pedestal top. An ideal magnetohydrodynamics stability code was developed to take account of toroidal rotation and clarified a destabilizing effect of rotation on the pedestal. Integrated SOL/divertor model clarified a mechanism of X-point multifaceted asymmetric radiation from edge. A model of the SOL flow driven by core particle orbits which partially enter the SOL was developed by introducing the ion-orbit-induced flow to fluid equations.

  17. 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.

  18. Control of Current Profile and Instability by Radiofrequency Wave Injection in JT-60U and Its Applicability in JT-60SA

    NASA Astrophysics Data System (ADS)

    Isayama, A.; Suzuki, T.; Hayashi, N.; Ide, S.; Hamamatsu, K.; Fujita, T.; Hosoyama, H.; Kamada, Y.; Nagasaki, K.; Oyama, N.; Ozeki, T.; Sakata, S.; Seki, M.; Sueoka, M.; Takechi, M.; Urano, H.

    2007-09-01

    Recent results of control of current profile and instability using radiofrequency wave in JT-60U and prediction analysis in JT-60SA are descried. In JT-60U, control of current profile in high-beta regime was demonstrated by using a real-time system, where the motional Stark effect diagnostic and lower hybrid wave were used as a detector and actuator, respectively. The minimum value of the safety factor was raised from 1.3 to 1.7 so as to follow the commanded value. Complete stabilization of a neoclassical tearing mode (NTM) with the poloidal mode number m = 2 and the toroidal mode number n = 1 was demonstrated using electron cyclotron (EC) current drive. By scanning the location of EC current drive in detail, strong stabilization effect was found for misalignment less than about half of the full island width. In addition, destabilization of the 2/1 NTM was observed for misalignment comparable to the full island width. Simulation of NTM stabilization in JT-60SA was performed by using the TOPICS code combined with the modified Rutherford equation. The TOPICS simulation showed that complete stabilization can be achieved more effectively by optimizing the EC wave injection angle and modulating the EC wave.

  19. 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.

  20. Control of Current Profile and Instability by Radiofrequency Wave Injection in JT-60U and Its Applicability in JT-60SA

    SciTech Connect

    Isayama, A.; Suzuki, T.; Hayashi, N.; Ide, S.; Hamamatsu, K.; Fujita, T.; Hosoyama, H.; Kamada, Y.; Oyama, N.; Ozeki, T.; Sakata, S.; Seki, M.; Sueoka, M.; Takechi, M.; Urano, H.; Nagasaki, K.

    2007-09-28

    Recent results of control of current profile and instability using radiofrequency wave in JT-60U and prediction analysis in JT-60SA are descried. In JT-60U, control of current profile in high-beta regime was demonstrated by using a real-time system, where the motional Stark effect diagnostic and lower hybrid wave were used as a detector and actuator, respectively. The minimum value of the safety factor was raised from 1.3 to 1.7 so as to follow the commanded value. Complete stabilization of a neoclassical tearing mode (NTM) with the poloidal mode number m = 2 and the toroidal mode number n = 1 was demonstrated using electron cyclotron (EC) current drive. By scanning the location of EC current drive in detail, strong stabilization effect was found for misalignment less than about half of the full island width. In addition, destabilization of the 2/1 NTM was observed for misalignment comparable to the full island width. Simulation of NTM stabilization in JT-60SA was performed by using the TOPICS code combined with the modified Rutherford equation. The TOPICS simulation showed that complete stabilization can be achieved more effectively by optimizing the EC wave injection angle and modulating the EC wave.

  1. 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.

  2. Antimisting kerosene JT3 engine fuel system integration study

    NASA Technical Reports Server (NTRS)

    Fiorentino, A.

    1987-01-01

    An analytical study and laboratory tests were conducted to assist NASA in determining the safety and mission suitability of the modified fuel system and flight tests for the Full-Scale Transport Controlled Impact Demonstration (CID) program. This twelve-month study reviewed and analyzed both the use of antimisting kerosene (AMK) fuel and the incorporation of a fuel degrader on the operational and performance characteristics of the engines tested. Potential deficiencies and/or failures were identified and approaches to accommodate these deficiencies were recommended to NASA Ames -Dryden Flight Research Facility. The result of flow characterization tests on degraded AMK fuel samples indicated levels of degradation satisfactory for the planned missions of the B-720 aircraft. The operability and performance with the AMK in a ground test engine and in the aircraft engines during the test flights were comparable to those with unmodified Jet A. For the final CID test, the JT-3C-7 engines performed satisfactorily while operating on AMK right up to impact.

  3. 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.

  4. 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.

  5. Preliminary Studies of the JT-60SA Cryogenic System

    NASA Astrophysics Data System (ADS)

    Lamaison, V.; Balaguer, D.; Gros, G.; Hoa, C.; Marchal, J. L.; Michel, F.; Reynaud, P.; Roussel, P.; Wanner, M.

    2010-04-01

    For the superconducting tokamak JT-60SA, one of the major projects within the Broader Approach Agreement between Europe and Japan, CEA is in charge of the cryoplant system. Preliminary studies were performed in order to prepare the specifications. The presentation focuses on the modelling of two operating modes, the baking and the cool down, and on a study of the economics of the electrical power distribution of the warm compression station. Baking mode consists in heating the vacuum vessel to 473 K during several days to "clean" surfaces. Because of the increased radiation heat loads from the vacuum vessel on the thermal shields, the helium mass flow at 80 K has to be increased by 50%. To avoid designing the cryogenic plant for this occasional overload, different scenarios were studied. During cool down mode, the mass flows have been calculated to ensure the required cool down speed. The limiting factors are the pressure drop in the coil windings and the magnet cool down speed. The warm compressor station represents a large part of the investment cost and is the main consumer of electrical power of the cryogenic system. Different compressors and motors have been analysed to optimise power consumption vs. investment costs.

  6. 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.

  7. Development of the Hybrid Jt-Expander Cycle for NG Liquefaction Cycle

    NASA Astrophysics Data System (ADS)

    Baek, S.; Hwang, G.; Jeong, S.

    2010-04-01

    Two liquefaction cycles for LNG (liquefied natural gas) production are compared in this paper. One is a well known MR (mixed refrigerant) JT cycle with two phase separators and four heat exchangers. Another one is the novel concept of hybrid cycle, which is to replace the last stage JT expansion with a turbine expander. The inlet flow to the turbine expander is deliberately warmed up by NG (natural gas) stream to guarantee superheated vapor phase and increase useful work. The turbine expander is to extract pressure exergy and reduce entropy generation by producing work and alleviating work requirement in the compressor. This paper describes the detailed processes of hybrid JT-expander cycle and the quantitative comparison results by HYSYS simulation under some realistic physical constraints.

  8. An efficient multi-stage Brayton-JT cycle for liquefaction of natural gas

    NASA Astrophysics Data System (ADS)

    Chang, Ho-Myung; Chung, Myung Jin; Lee, Sanggyu; Choe, Kun Hyung

    2011-06-01

    Combined multi-stage Brayton-JT refrigeration cycles are investigated as a governmental effort in Korea to develop an original liquefaction process of natural gas in accordance with recent demand of higher efficiency and larger capacity. Based upon thermodynamic optimization theory, a combined refrigeration system is proposed with nitrogen (N2) Brayton cycle, ethylene (C2) JT cycle, and propane (C3) JT cycles, which are used for cooling the feed gas in a series of heat exchangers. Since no mixed refrigerants are used, this system is simple in operation and robust in reliability. A complete cycle design is presented to confirm its feasibility and estimate the liquefaction performance. It is expected that the proposed N2-C2-C3 cycle could have a reasonably high efficiency and the potential of great liquefaction capacity. Next steps are underway for patent application and practical process development.

  9. 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.

  10. Pratt and Whitney Aircraft JT8D turbofan engine. performance improvement to offset rising fuel costs

    SciTech Connect

    Fahle, R.K.

    1980-01-01

    A Pratt and Whitney Aircraft Group program begun in 1978 has led to the development of retrofit kit packages and major engine modifications that will provide thrust-specific fuel consumption (TSFC) reductions of 2.1% for the JT8D-1 and -7 engines, 3.0% for the JT8D-9 engine, and 5.5% for the JT8D-15, -17, and -17R engines under cruise conditions, and comparable fuel savings under other conditions. The modifications being made will affect the fan, compressor, and turbine sections of the engines to improve component efficiency. The retrofit kits will be used on existing in-service engines; other modifications will be introduced in service during 1981 and 1982. Fuel savings per engine per year could range from 27,000 to 91,000 gal, and fleet savings could amount to several hundred million gallons per year.

  11. 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.

  12. Development of a cryogenic mixed fluid J-T cooling computer code, 'JTMIX'

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1991-01-01

    An initial study was performed for analyzing and predicting the temperatures and cooling capacities when mixtures of fluids are used in Joule-Thomson coolers and in heat pipes. A computer code, JTMIX, was developed for mixed gas J-T analysis for any fluid combination of neon, nitrogen, various hydrocarbons, argon, oxygen, carbon monoxide, carbon dioxide, and hydrogen sulfide. When used in conjunction with the NIST computer code, DDMIX, it has accurately predicted order-of-magnitude increases in J-T cooling capacities when various hydrocarbons are added to nitrogen, and it predicts nitrogen normal boiling point depressions to as low as 60 K when neon is added.

  13. Electron {sup 83}Rb/{sup 83m}Kr Source for the Energy Scale Monitoring in the KATRIN Experiment

    SciTech Connect

    Zboril, Miroslav; Collaboration: KATRIN Collaboration

    2011-12-16

    The KATRIN (KArlsruhe TRItium Neutrino) experiment investigates the endpoint region of the tritium {beta}-spectrum aiming for the sensitivity on the neutrino mass of 0.2 eV (90% C.L.). A spectrometer of the MAC-E filter (Magnetic Adiabatic Collimation with an Electrostatic filter) type will be used for a total time of at least 5 years. An unrecognized shift of the filtering potential would directly influence the resulting neutrino mass. To continuously monitor the filtering potential the high voltage (HV) will be simultaneously applied to an additional MAC-E filter spectrometer. In this monitor spectrometer suitable electron sources based on atomic/nuclear standards will be utilized. As one of such monitoring tools the solid {sup 83}Rb/{sup 83m}Kr source is intended. It provides conversion electrons from {sup 83m}Kr(t{sub 1/2} = 1.83 h) which is continuously generated by {sup 83}Rb(t{sub 1/2}{approx_equal}86 d). The Calibration and Monitoring task of the KATRIN project demands the long-term energy stability {Delta}E/E of the K-32 conversion electron line (E = 17.8 keV, {Gamma} = 2.7 eV) of {+-}1.6 ppm/month.

  14. Stability of the toroidicity-induced Alfven eigenmodes in JT-60U ICRF experiments

    SciTech Connect

    Fu, G.Y.; Cheng, C.Z.; Kimura, H.; Ozeki, T.; Saigusa, M.

    1996-04-01

    It is shown that the stability of toroidicity-induced Alfven eigenmodes (TIE) in JT-60U ICRF experiments is strongly dependent on mode location. This dependence results in sequential excitation of high-n TIE modes as the central safety factor, q, drops in time.

  15. Collective Thomson scattering using a pulsed CO2 laser in JT-60U

    NASA Astrophysics Data System (ADS)

    Kondoh, T.; Lee, S.; Hutchinson, D. P.; Richards, R. K.

    2001-01-01

    A collective Thomson scattering (CTS) diagnostic system using a carbon dioxide (CO2) laser has been developed for the purpose of establishing measurement technique of ion temperature and fast alpha particle in a fusion reaction plasma. A pulsed CO2 laser (15 J, 1 ?s at 10.6 ?m) and a heterodyne receiver with a stray light notch filter has been successfully installed. The noise equivalent power of the heterodyne receiver is below 910-19 W/Hz up to a frequency of 8 GHz. A six-channel filter bank analyzes the spectrum of the scattered light in the frequency range from 0.4 to 4.5 GHz to measure ion temperature and to detect fast ions generated by negative-ion source neutral beam injection of the JT-60U (Japan Atomic Energy Research Institute Tokamak 60-Upgrade) plasmas [S. Ishida, JT-60U Team, Nucl. Fusion 39, 1211 (1999)]. Test of the CTS system by injecting the CO2 laser into the vacuum vessel of JT-60U has started. Stray light signal around the JT-60U vacuum vessel was detected and optimization of the optical alignment has proceeded.

  16. 76 FR 72130 - Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ...We propose to supersede an existing airworthiness directive (AD) that applies to all Pratt & Whitney (PW) JT9D series turbofan engines. The existing AD currently requires revisions to the Airworthiness Limitations Section (ALS) of the manufacturer's Instructions for Continued Airworthiness (ICA) to include required enhanced inspection of selected critical life-limited parts at each piece-part......

  17. Development and Operational Experiences of the JT-60U Tokamak and Power Supplies

    SciTech Connect

    Hosogane, N.; Ninomiya, H.; Matsukawa, M.; Ando, T.; Neyatani, Y.; Horiike, H.; Sakurai, S.; Masaki, K.; Yamamoto, M.; Kodama, K.; Sasajima, T.; Terakado, T.; Ohmori, S.; Ohmori, Y.; Okano, J.

    2002-09-15

    The design of the JT-60U tokamak, the configuration of the coil power supplies, and the operational experiences gained to date are reviewed. JT-60U is a large tokamak upgraded from the original JT-60 in order to obtain high plasma current, large plasma volume, and highly elongated divertor configurations. All components inside the toroidal magnetic field coils, such as vacuum vessel, poloidal magnetic field coils, divertor, etc., were modified. Various technologies and ideas were introduced to develop these components; for example, a multi-arc double skin wall structure for the vacuum vessel and a functional poloidal magnetic field coil system with taps for obtaining various plasma configurations. Furthermore, boron-carbide coated carbon fiber composite (CFC) tiles were used as divertor tiles to reduce erosion of carbon-base tiles. Later, a semiclosed divertor with pumps, for which cryo-panels originally used for NBI units were converted, was installed in the replacement of the open divertor. These development and operational results provide data for future tokamaks. Major failures experienced in the long operational period of JT-60U, such as water leakage from the toroidal magnetic field coil, fracture of carbon tiles, and breakdown of a filter capacitor, are described. As a maintenance issue for tokamaks using deuterium fueling gas, a method for reducing radiation exposure of in-vessel workers is described.

  18. 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.

  19. 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).

  20. Mixed-refrigerant Joule-Thomson (MR JT) mini-cryocoolers

    NASA Astrophysics Data System (ADS)

    Tzabar, Nir

    2014-01-01

    This paper presents the progress in our ongoing research on Mixed-Refrigerant (MR) Joule-Thomson (JT) cryocoolers. The research begun by exploring different MRs and testing various compressors: oil-lubricated and oil-free, reciprocating and linear, custom-made and commercial. Closed-cycle JT cryocoolers benefit from the fact that the compressor might be located far from the cold-end and thus there are no moving parts, no vibrations, and no heat emission near the cold-end. As a consequence, the compressor may be located where there are no severe size limitations, its heat can be conveniently removed, and it can be easily maintained. However, in some applications there is still a demand for a small compressor to drive a JT cryocooler although it is located far from the cooled device. Recently, we have developed a miniature oil-free compressor for MR JT cryocoolers that weighs about 700 g and its volume equals about 300 cc. The cryocooler operates with a MR that contains Ne, N2, and Hydrocarbons. This MR has been widely investigated with different compressors and varying operating conditions and proved to be stable. The current research investigates the performances of MR JT mini-cryocooler operating with the MR mentioned above, driven with our miniature compressor, and a cold-finger prototype. A Dewar with heat load of about 230 mW is cooled to about 80 K at ambient temperatures between 0C and 40C. The experimental results obtained are stable and demonstrate the ability to control the cooling temperature by changing the rotation speed of the compressor.

  1. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    DOE PAGESBeta

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high sourcemore » luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.« less

  2. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    SciTech Connect

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high source luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.

  3. Severe Septic Patients with Mitochondrial DNA Haplogroup JT Show Higher Survival Rates: A Prospective, Multicenter, Observational Study

    PubMed Central

    Martn, Mara M.; Lpez-Gallardo, Esther; Sol-Violn, Jordi; Blanquer, Jos; Labarta, Lorenzo; Daz, Csar; Borreguero-Len, Juan Mara; Jimnez, Alejandro; Montoya, Julio; Ruiz-Pesini, Eduardo

    2013-01-01

    Objective In a previous cohort study (n=96), we found an association between mitochondrial (mt) DNA haplogroup JT and increased survival of severe septic patients, after controlling for age and serum lactic acid levels. The aim of this research was to increase the predictive accuracy and to control for more confounder variables in a larger cohort (n=196) of severe septic patients, to confirm whether mtDNA haplogroup JT influences short and medium-term survival in these patients. Methods We conducted a prospective, multicenter, observational study in six Spanish Intensive Care Units. We determined 30-day and 6-month survival and mtDNA haplogroup in this second cohort of 196 patients and in the global cohort (first and second cohorts combined) with 292 severe septic patients. Multiple logistic regression and Cox regression analyses were used to test for the association of mtDNA haplogroups JT with survival at 30-days and 6-months, controlling for age, sex, serum interleukin-6 levels and SOFA score. Results Logistic and Cox regression analyses showed no differences in 30-day and 6-month survival between patients with mtDNA haplogroup JT and other haplogroups in the first cohort (n=96). In the second cohort (n=196), these analyses showed a trend to higher 30-day and 6-month survival in those with haplogroup JT. In the global cohort (n=292), logistic and Cox regression analyses showed higher 30-day and 6-month survival for haplogroup JT. There were no significant differences between J and T sub-haplogroups in 30-day and 6-month survival. Conclusions The global cohort study (first and second cohorts combined), the largest to date reporting on mtDNA haplogroups in septic patients, confirmed that haplogroup JT patients showed increased 30-day and 6-month survival. This finding may be due to single nucleotide polymorphism defining the whole haplogroup JT and not separately for J or T sub-haplogroups. PMID:24069186

  4. Tritium Recovery at Fusion Facility 4.Tritium Experience in JT-60 Operation

    NASA Astrophysics Data System (ADS)

    Oikawa, Akira; Miya, Naoyuki

    The tritium effluent of JT-60 vacuum exhaust through the stack and into the environment always remains below the detectable level. Tritium concentration in the drain water is below a limit of regulation by the local agreement and the law, though small tritium contamination in facility drains and in rain drains of the stack has occasionally been detected. Following an annual deuterium plasma discharge campaign, a 4-week hydrogen or helium plasma discharge campaign and subsequent ventilation of room air reduced the tritium concentration on the surface of in-vessel components back to ground level and then the in-vessel was ready for the maintenance. A cooperative endeavor is underway to complete an analysis of tritium behaviors in JT-60.

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  6. Comparison of tritium retention and carbon deposition in JET and JT-60U

    NASA Astrophysics Data System (ADS)

    Tanabe, T.; Sugiyama, K.; Coad, P.; Bekris, N.; Glugla, M.; Miya, N.

    2005-10-01

    Profiles of T retention in the Mark IIA divertor of JET and H/D and T retention in the W-shaped divertor of JT-60U are compared. Hydrogen (H, D and T) is retained in carbon deposited layers with nearly constant concentration throughout the layers, except high energy triton directly impinging into more than 1 ?m in depth. However, carbon deposition profiles and hydrogen retention are strongly influenced by geometrical structure of the divertor and tile alignment as well as by magnetic field lines. Carbon deposition on the divertor base tile in JET shows stripes parallel to magnetic filed lines, suggesting a direct plasma deposition process. In JT-60U, the temperature of the co-deposited layers during operation plays critically important role on the hydrogen retention. It seems possible to reduce tritium inventory significantly by increasing the surface temperature of the plasma facing components.

  7. 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.

  8. Observation of a Complex Multistage Transition in the JT-60U H-mode Edge

    SciTech Connect

    Kamiya, K.; Sakamoto, Y.; Matsunaga, G.; Kojima, A.; Urano, H.; Oyama, N.; Koide, Y.; Kamada, Y.; Ida, K.

    2010-07-23

    A complex multistage transition of the edge radial electric field is observed in JT-60U H-mode phase without edge localized mode. An interesting feature is that the poloidal rotation velocity of the carbon impurity ions changes in the later H-phase without a comparable change in the main ion pressure gradient, indicating a change in the parallel momentum (and particle) balance channel.

  9. Plasma Current Start-up by Outboard PF Coils in JT-60U and TST-2

    SciTech Connect

    Takase, Y.; Ejiri, A.; Ushigome, M.; Hanada, K.; Ide, S.; Mitarai, O.; Shiraiwa, S.

    2005-09-26

    Plasma current (Ip) initiation and ramp-up utilizing induction by poloidal field (PF) coils located on the outboard side of the torus were demonstrated in both conventional aspect ratio tokamak (100 kA in JT-60U) and spherical tokamak (10 kA in TST-2). In the presence of sufficient source of plasma by RF ionization (1 MW in JT-60U, 100 kW in TST-2), Ip formation is possible without the existence of a PF null, with the initial vertical field (Bv) in the direction opposite to that required for equilibrium. Utilization of the extra flux swing provided by the PF coils before Bv switches sign is important in arriving at a high enough Ip that matches Bv at the end of PF coil current ramp. In JT-60U, recharging of the OH coil was observed with only perpendicular and counter NB injection, suggesting overdrive by bootstrap current. In TST-2, a quasi-steady-state Ip of 4 kA was formed and sustained by RF power (PRF) alone, without the use of induction. The plasma current centroid of this type of plasma is located on the outboard side. The dependences of Ip on PRF and Bv were found to be weak. The results presented here offer encouragement to CS-less operation of a tokamak fusion reactor, which should have a large impact on the economic competitiveness.

  10. Impurity and particle recycling reduction by boronization in JT-60U

    NASA Astrophysics Data System (ADS)

    Higashijima, S.; Sugie, T.; Kubo, H.; Tsuji, S.; Shimada, M.; Asakura, N.; Hosogane, N.; Kawano, Y.; Nakamura, H.; Itami, K.; Sakasai, A.; Shimizu, K.; Ando, T.; Saidoh, M.

    1995-04-01

    In JT-60U boronization using decaborane was carried out. Boronization reduced the oxygen impurity in OH discharges and shortened the wall conditioning after the vacuum vessel vent and consequently enabled JT-60U to produce clean plasmas easily except for NB heated plasmas. After boronization, particle recycling was reduced drastically in OH and NB discharges. High confinement plasmas were obtained including high ?p mode and H-mode discharges. In the latest boronization part of divertor plates were replaced with B 4C coated tiles with a B 4C thickness 300 ?m. After introducing B 4C divertor tiles, an explosive generation of boron particles from the tiles was observed. By the combined effects of boronization with decaborane and boron generation from B 4C tiles, oxygen impurity was so low that oxygen line signals were reduced to noise levels after the latest boronization. On the other hand, boron burst from the B 4C tiles restricted the operation of JT-60U.

  11. 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.

  12. Risk of Mortality Associated With QT and JT Intervals at Different Levels of QRS Duration (from the Third National Health and Nutrition Examination Survey).

    PubMed

    Zulqarnain, Muhammad A; Qureshi, Waqas T; O'Neal, Wesley T; Shah, Amit J; Soliman, Elsayed Z

    2015-07-01

    QT prolongation in the setting of QRS >120 ms is believed to be triggered by prolonged depolarization rather than repolarization. Hence, JT interval is suggested as an alternative to QT interval when QRS duration is prolonged. It is unclear, however, if JT and QT intervals portend similar risk of mortality for different durations of QRS. We examined the association between QT and JT, separately, with all-cause mortality across different levels of QRS duration in 8,025 participants (60 13 years, 41% white and 54% women) from the Third National Health and Nutrition Examination Survey. At baseline (1986 to 1994), 486 participants (6%) had QRS duration ?120 ms. During a follow-up of up to 18 years, 3,045 deaths (38%) occurred. There were significant nonlinear relations of QT and JT intervals with mortality (p <0.001). Hence, QT and JT were categorized as prolonged (>95th percentile), shortened (<5th percentile), and normal (reference group). In multivariate-adjusted Cox regression models, prolonged JT (hazard ratio [HR] 4.75, 95% confidence interval [CI] 1.86 to 12.11) was associated with increased risk of mortality more than prolonged QT (HR 1.50, 95% CI 1.03 to 2.17) in participants with QRS ?120 ms (interaction p = 0.02). In participants with QRS duration <120 ms, prolonged QT and JT were equally predictive of all-cause mortality (HR 1.27, 95% CI 1.06 to 1.54, and HR 1.31, 95% CI 1.10 to 1.55, respectively). Similar patterns were observed with shortened QT and JT intervals. In conclusion, although both QT and JT intervals are predictive of mortality, JT is more predictive in the setting of QRS duration >120 ms supporting the use of JT interval in patients with prolonged QRS. PMID:25929581

  13. Understanding of the fundamental differences in JET and JT-60U AT discharges

    NASA Astrophysics Data System (ADS)

    Sirén, P.; Tala, T.; Corrigan, G.; Garcia, J.; Koskela, T.; Köchl, F.; Litaudon, X.; Salmi, A.; EFDA contributors, JET; the EU-ITM ITER Scenario Modelling Group

    2015-07-01

    Plasma current density simulations of JET and JT-60U shots in reverse-q advanced scenarios based on the previous data analysis of the identity plasma experiments have been performed. The effects of the main differences between the shots (neutral beam current density (jnbi), electron density and geometry) have been studied. The reversed q-profile (which was the target in this identity experiment and is observed at the beginning of each shot) was sustained in JT-60U while it became flat in JET towards the end of the shot. In JET, jnbi is peaked on-axis whereas in JT-60U it is peaked off-axis (at ρ = 0.5) while the NBI fraction of the selected shots is the same (22-24%). A strong density ITB appeared (at ρ = 0.5) in JT-60U but not in JET. The plasma geometry was mainly set to match but it was not identical. In addition, the extrapolation to JET steady-state operation has been done by testing the sensitivity of q to different externally driven currents, electron density and geometry in predictive current diffusion simulations. Moreover, critical bootstrap current density has been analysed. The reasons for the different time evolution of q-profile have been studied with predictive current simulations with the 1.5D transport code JETTO. The current diffusion model was validated against reverse-q shots, and simulations were performed with experimental data profiles, jNBI given by ASCOT and neoclassical resistivity and bootstrap current calculated by NCLASS. Bootstrap current density was the most efficient way to sustain the beneficial reverse shape of q-profile. Replacing the JET ne profile with one from JT-60U leads to an increase of 0.2-0.3 MA in the bootstrap current (f bs increases from 15% to 30%). However, sustaining the stationary reverse q is not achieved in JET with bootstrap current induced by the density gradient of JT-60U. Even 10 times larger gradient than in JT-60U helps to sustain the shape of the q-profile longer than the experimentally observed density profile in JET but the minimum value of q moves closer to central plasma and the shape of q is not stationary in a 10 s simulation. The effect of different shape of NBI current density profile is negligible due to quite small fraction. Sustaining the reverse q requires 45% or larger added off-axis fraction. However, increasing the inverse aspect ratio increases bootstrap current and decreases the critical bootstrap current more effectively than increasing the density gradient: two times larger inverse aspect ratio produces almost three times larger bootstrap fraction but ten times larger density gradient only two times larger bootstrap fraction. The conclusions based on these simulations indicate that the need for bootstrap current is larger in JET and the same conditions cause smaller bootstrap fraction, which suggests that achieving steady-state operation in JET under these conditions is unlikely.

  14. Progress in long-pulse production of powerful negative ion beams for JT-60SA and ITER

    NASA Astrophysics Data System (ADS)

    Kojima, A.; Umeda, N.; Hanada, M.; Yoshida, M.; Kashiwagi, M.; Tobari, H.; Watanabe, K.; Akino, N.; Komata, M.; Mogaki, K.; Sasaki, S.; Seki, N.; Nemoto, S.; Shimizu, T.; Endo, Y.; Ohasa, K.; Dairaku, M.; Yamanaka, H.; Grisham, L. R.

    2015-06-01

    Significant progress in the extension of pulse durations of powerful negative ion beams has been made to realize the neutral beam injectors for JT-60SA and ITER. In order to overcome common issues of the long-pulse production/acceleration of negative ion beams in JT-60SA and ITER, new technologies have been developed in the JT-60SA ion source and the MeV accelerator in Japan Atomic Energy Agency. As for the long-pulse production of high-current negative ions for the JT-60SA ion source, the pulse durations have been successfully increased from 30 s at 13 A on JT-60U to 100 s at 15 A by modifying the JT-60SA ion source, which satisfies the required pulse duration of 100 s and 70% of the rated beam current for JT-60SA. This progress was based on the R&D efforts for the temperature control of the plasma grid and uniform negative ion productions with the modified tent-shaped filter field configuration. Moreover, each parameter of the required beam energy, current and pulse has been achieved individually by these R&D efforts. The developed techniques are useful to design the ITER ion source because the sustainment of the caesium coverage in the large extraction area is one of the common issues between JT-60SA and ITER. As for the long-pulse acceleration of high power density beams in the MeV accelerator for ITER, the pulse duration of MeV-class negative ion beams has been extended by more than 2 orders of magnitude by modifying the extraction grid with a high cooling capability and a high transmission of negative ions. A long-pulse acceleration of 60 s has been achieved at 70 MW m-2 (683 keV, 100 A m-2) which has reached the power density of JT-60SA level of 65 MW m-2. No degradations of the voltage holding capability of the acceleration voltage and the beam optics due to the distortion of the acceleration grids have been observed in this power density level. These results are the longest pulse durations of high-current and high-power-density negative ion beams in the world.

  15. 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.

  16. 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...

  17. An online FT-ICR Penning-trap mass spectrometer for the DPS2-F section of the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Heck, M.; Ascher, P.; Cakirli, R. B.; Golzke, H.; Rodrguez, D.; Stahl, S.; Ubieto-Daz, M.; Blaum, K.

    2014-09-01

    Two Fourier-transform ion-cyclotron resonance (FT-ICR) Penning-trap mass spectrometers will be installed in the pumping section of the KArlsruhe TRItium Neutrino (KATRIN) experiment. This experiment aims at determining the electron anti-neutrino mass m(?ebar) with a sensitivity of 0.2 eV (90% C.L.) by high-resolution tritium ?-spectroscopy. The tritium source creates various types of ions, which have to be reduced in order to reach the required low background level. The purpose of the FT-ICR mass spectrometers is the identification of the ion flux components as well as their abundance. Furthermore, the pumping efficiency of the differential pumping section DPS2-F can be determined since these Penning traps will be installed one at the entrance and one at the exit. In this paper the operation of the FT-ICR system is described. Experimental results are presented concerning the cryogenic broad-band amplifier system for the FT-ICR detection as well as the characterisation of the mass spectrometer with respect to, e.g., noise density and detection limit.

  18. 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

  19. Progress of high-power and long-pulse ECRF system development in JT-60

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Isayama, A.; Yokokura, K.; Shimono, M.; Hasegawa, K.; Sawahata, M.; Suzuki, S.; Terakado, M.; Hiranai, S.; Sato, F.; Wada, K.; Hinata, J.; Sato, Y.; Ohzeki, M.; Takahashi, K.; Kajiwara, K.; Oda, Y.; Kasugai, A.; Sakamoto, K.; Hoshino, K.; Moriyama, S.

    2011-10-01

    A new gyrotron operation technique to increase oscillation efficiency was developed using the JT-60 electron cyclotron range of frequency (ECRF) system. In order to increase the efficiency without a significant increase in the anode leakage current by trapped electrons that limits the efficiency of gyrotrons with a collector potential depression technology, we actively optimized the electron pitch factor by controlling only the anode voltage within ~0.1 s after the start of the gyrotron operation, and a high-efficiency oscillation in the so-called hard-self-excitation region was achieved from the start of the oscillation. As an application of this technique in the JT-60 ECRF system, the gyrotron output power of 1.5 MW for 4 s, which is the longest pulse length in the world at an output power of 1.5 MW, was recorded with a successful reduction in the collector heat load by 20% as compared with the conventional operation. The reduced collector heat load at the 1.5 MW operation was acceptable for a steady-state operation. Further progress was made with respect to the expansion of the long-pulse capability of the ECRF system. A new gyrotron with an improved mode converter was developed in order to demonstrate a reduction in the stray radiation in the gyrotron; such radiation has thus far hindered long-pulse operations by causing an unacceptable heat load. We confirmed that the stray radiation was reduced to 1/3 of that of the original gyrotron; this reduced heat load is acceptable for steady-state operation. A conditioning operation of the improved gyrotron proceeds up to 31 s at 1 MW. This progress significantly contributes to an enhancement in the high-power and long-pulse capability of the ECRF system used in JT-60SA, where a total output power of 9 MW for 100 s is planned.

  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. JT-60U Plasma Current Measurement by an Optical Current Transformer

    SciTech Connect

    Arai, Takashi; Nishiyama, Tomokazu; Yagyu, Junichi; Kasai, Satoshi; Sone, Isamu; Abe, Mitsushi; Miya, Naoyuki

    2004-01-15

    In a nuclear fusion experiment device, a plasma discharge is to be sustained for a long time in steady state operation. In such a device an electromagnetic sensor that has a signal integrator to measure direct currents will cause a technical problem of zero point drift on signals. Therefore, the detection device using new technology for direct current measurement, optical current transformer (optical CT), was developed. The device has an optical fiber specified for 850 and 1550nm (wavelength) were manufactured, and was applied to current measurement in JT-60U experiments. A gamma ray irradiation examination was also done to the optical CT.

  2. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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.

  4. Design of collection optics and polychromators for a JT-60SA Thomson scattering system

    SciTech Connect

    Tojo, H.; Hatae, T.; Sakuma, T.; Hamano, T.; Itami, K.; Aida, Y.; Suitoh, S.; Fujie, D.

    2010-10-15

    This paper presents designs of collection optics for a JT-60SA Thomson scattering system. By using tangential (to the toroidal direction) YAG laser injection, three collection optics without strong chromatic aberration generated by the wide viewing angle and small design volume were found to measure almost all the radial space. For edge plasma measurements, the authors optimized the channel number and wavelength ranges of band-pass filters in a polychromator to reduce the relative error in T{sub e} by considering all spatial channels and a double-pass laser system with different geometric parameters.

  5. 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.

  6. 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.

  7. 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.

  8. Development of High Power Gyrotron and Power Modulation Technique using the JT-60U ECRF System

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takayuki; Terakado, Masayuki; Sato, Fumiaki; Yokokura, Kenji; Shimono, Mitsugu; Hasegawa, Koichi; Sawahata, Masayuki; Suzuki, Sadaaki; Hiranai, Shinichi; Igarashi, Koichi; Wada, Kenji; Suzuki, Takashi; Kajiwara, Ken; Kasugai, Atsushi; Sakamoto, Keishi; Isayama, Akihiko; Matsunaga, Go; Moriyama, Shinichi

    Electron cyclotron range of frequency system of the JT-60U finished operation at the end of August 2008, and improvements toward JT-60SA have been started. In the last two years stable gyrotron oscillation at an output power of 1.5 MW for 1 s was demonstrated, for the first time, using the 110 GHz gyrotron. It was verified that the heat load on the cavity was at an acceptable level with continuous oscillations at 1.5 MW. The absorption power of the collector was also at an acceptable level for the longer pulse oscillation of 5 s. A power modulation technique based on anode voltage modulation was also developed in order to study the effects of modulated Electron Cyclotron Current Drive (ECCD) on Neoclassical Tearing Mode (NTM) stabilization. Modulation frequencies of up to 7 kHz were achieved at output power of 0.8 MW exceeding the previous limit of 3 kHz. Modulated ECCD experiments in synchronization with the NTM were successfully performed with a modulation frequency of around 5 kHz. Development of an accurate synchronization system played an essential role in the experiments that needed a maintained phase between the magnetic probe signal and modulated ECCD in real time. The results provide significant information for further developments that will enhance the overall performance of ECRF systems in the near future.

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    This paper presents the results of testing to identify the effects of simulated aerodynamic flight loads on JT9D engine performance. 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 and 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.

  10. Power flow in the negative-ion based neutral beam injection for JT-60

    NASA Astrophysics Data System (ADS)

    Kuriyama, M.; Akino, N.; Ebisawa, N.; Grisham, L.; Hikita, S.; Honda, A.; Itoh, T.; Kawai, M.; Kazawa, M.; Kusaka, M.; Mogaki, K.; Ohga, T.; Okumura, Y.; Oohara, H.; Satoh, F.; Seki, H.; Tanai, Y.; Toyokawa, Y.; Umeda, N.; Usui, K.; Watanabe, K.; Yamaguchi, M.; Yamazaki, H.

    2000-02-01

    The negative ion based neutral beam injection system for JT-60 has operated since 1996 injecting neutral beam into JT-60 plasmas. A power flow measurement in the beam line and ion source with a water calorimeter had shown that 40%-50% of accelerated beam particles were intercepted on the two accelerator grids and the grounded grid at an ion source gas pressure of 0.2-0.3 Pa. Much of the beam loss was not caused by stripping loss of the negative ions, but rather by direct impingement of the negative ions onto the grids. After reducing the acceleration area by masking the edge area (about 13% of the extraction area) of the accelerator grid so as to minimize the edge effect of magnetic field in the arc chamber, the loss in the accelerator decreased by roughly 25%. In comparing a deuterium beam with a hydrogen beam, the neutral beam power with deuterium is lower by 30% than that of hydrogen at the same arc power, although the heat load onto the grounded grid does not change so much. The power deposition ratios along the beamline were as follows: the beam scraper in the ion source tank and the neutralizer cell received about 3% and about 7%, respectively, of the accelerated beam power, while the ion dumps for both D- and D+ received 20%-30% in total, and 30%-34% reached the neutral beam calorimeter.

  11. Development and operation of first wall in JT-60U high-power heated discharges

    SciTech Connect

    Masaki, K.; Kodama, K.; Arai, T.; Hiratsuka, H.; Yagyu, J.; Saidoh, M.; Ogiwara, N.; Higashijima, S.

    1995-12-31

    In JT-60U, the highest fusion product of 1.2 {times} 10{sup 21} keV sm{sup {minus}3} was recorded in July 1994, and the confinement performance has been also improved in the quasi-steady states (duration time {approximately}1.5s). The JT-60U has various wall conditioning methods. In particular, boronization system using decaborane and B{sub 4}C-converted CFC divertor tiles were effective for reduction of the oxygen impurity and particle recycling. In the latest boronization session, gas mixture of deuterium and helium was used in glow discharge instead of helium only to reduce the hydrogen content in the boron film. On the other hand, the B{sub 4}C-converted CFC tiles caused, so called, the real-time solid target boronization (STB) by plasma impact, and then low concentration level of impurities was achieved. Water cooling of the divertor tiles, which was carried out in October 1994, was also effective for the reduction of impurity production. The amount of neutron and tritium generated by D-D reaction have also increased with the improved plasma performance. From the measurement of the tritium in the first wall tiles, it is expected that tritium of 1.6 {times} 10{sup 10} Bq, which corresponds to approximately 50% of tritium generated until 1993, still remained in the first wall.

  12. Properties of thin boron coatings formed during deuterated-boronization in JT-60

    NASA Astrophysics Data System (ADS)

    Yagyu, J.; Ogiwara, N.; Saidoh, M.; von Seggern, J.; Okabe, T.; Miyo, Y.; Hiratsuka, H.; Yamamoto, S.; Goppelt-Langer, P.; Aoki, Y.; Takeshita, H.; Naramoto, H.

    1997-02-01

    Since 1992, the boronization using B10H14 (decaborane-based boronization) has been utilized in JT-60 once or twice a year. It is very effective in reducing both the impurities, like oxygen and carbon, in the plasma and in recycling fuel particles. However, we needed 500 discharges to exchange hydrogen in the boron film for deuterium, after the boronization using only He for a dilution gas. Using a mixed-dilution gas of He and deuterium, we made the boronized film on JT-60 first wall (deuterated-boronization). A typical composition of working gas was 2% B 10H 14, 38% D 2 and 60% He, which was used in a flow through situation. The amounts of hydrogen and deuterium in the boronized film were evaluated to be 5 and 30 at%, respectively. In addition, the deuteration factor of {D}/{(H + D)} in the first plasma after the boronization increased from less than 0.2 to 0.8. Thus, we can drastically reduce the number of the conditioning discharges from 500 to 50 for the isotope-exchange before D plasma experiments.

  13. 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.

  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. Transient Heat Transport in Subcooled He II Associated with JT Effect

    SciTech Connect

    Maekawa, R.; Iwamoto, A.; Hamaguchi, S.

    2004-06-23

    Transient heat transport in subcooled He II has been investigated in a 1 m long rectangular channel with distributed contractions: one-closed end has a heater, while the other end is open to the He II bath. Experiments were conducted applying heat pulses and recording the temperature profile with seven Allan Bradley resistors placed along the channel. Cernox sensor was indium soldered on the heater surface to monitor the onset of film boiling. As the onset of heat pulse, the pressure at the heater surface increased because of phase change from subcooled He II to He I. Further increasing of heat pulse leads to coexistence of triple-phase, He I vapor layer, He I and subcooled He II, at the vicinity of heater surface. These effects induced instantaneous He II temperature drop along the channel, which is caused by Joule-Thomson (JT) effect. A simple model gives an approximate mechanism of pressure increase in the channel. The paper describes transient heat transport mechanism in the channel and discusses JT effect within the channel.

  16. Overview of JT-60U results towards the resolution of key physics and engineering issues in ITER and JT-60SA

    NASA Astrophysics Data System (ADS)

    Isayama, A.; JT-60 Team

    2011-09-01

    This paper presents an overview of recent results from JT-60U. Topics we particularly focus on are (1) the mechanism determining the rotation profile and the effect of rotation on/from transport and stability, (2) the edge localized mode (ELM) physics and active ELM control and (3) plasma-wall interactions. An analysis of the momentum transport showed that rotation with a high pressure gradient can be reproduced by introducing a residual stress term proportional to the momentum diffusivity and the pressure gradient. Also, the momentum diffusivity in an internal transport barrier (ITB) region was reduced to an order similar to that of the ion thermal diffusivity. A comparison of the edge pedestal characteristics between JT-60U and JET with matched shape and operational parameters showed that the edge pressure did not change with increasing toroidal field (TF) ripple up to 1%, whereas a linear shift of the rotation velocity to the counter-direction was observed with increasing TF ripple. The absolute evaluation of tungsten accumulation in the core plasma by a spectroscopic method clarified that tungsten accumulation increased with increasing toroidal rotation in the counter-direction while an H-mode was sustained even at a tungsten density of 10-3 times the electron density. Active control of neoclassical tearing mode (NTM) islands by the electron cyclotron current drive showed that the growth of NTM islands decelerated the plasma rotation. A transition to a low-rotation frequency state occurred for larger NTM islands. A statistical analysis of the precursor of type I ELM showed a small growth rate of γ/ωA ~ 10-3 (where γ and ωA are the growth rate and Alfvén angular frequency, respectively). The measurement of the precursor at different toroidal locations showed that the toroidal mode number was 8-10 or 14-16. Energetic-particle-driven wall modes (EWMs) were found to trigger ELMs and decrease the ELM amplitude to half of that without EWMs. Enhancement of the ELM frequency by electron cyclotron heating in the edge region of the high-field side was observed, and the frequency increase was four times than that of neutral beam injection cases having the same absorption power. Laser scattering measurement of carbon dust generation showed that the dust distribution had a peak in the far scrape-off layer and penetration into the core plasma was not significant. Depth profile measurements of deuterium and carbon in tungsten-coated tiles (tungsten thickness: 50 µm) determined that the ratio of deuterium to carbon was 0.06 ± 0.02 over a 20 µm depth, suggesting deuterium trapping by carbon in the tungsten layer. Furthermore, new records for both the beam energy of negative-ion-based neutral beams (507 keV) and the output power of 110 GHz electron cyclotron waves (1.5 MW for 4 s from one gyrotron) were achieved, which confirmed and extended the heating and current drive capabilities of ITER and JT-60SA.

  17. Dependence of pedestal structure on collisionality at fixed beta in JT-60U

    NASA Astrophysics Data System (ADS)

    Urano, H.; Aiba, N.; Kamiya, K.; Kamada, Y.; the JT-60 Team

    2016-01-01

    The dependence of pedestal structure on collisionality at fixed beta has been investigated in JT-60U. In the ITER-relevant low collisionality regime, the pedestal width does not change with edge collisionality. In the high collisionality regime, the pedestal width broadens with increased edge collisionality. The pedestal pressure gradient and width are not significantly changed when the pedestal is close to an intermediate n peeling-ballooning mode boundary at low collisionality. The experimental result indicates that conventional pedestal models where the pedestal width is independent of collisionality and is determined by {?\\text{p}} at the pedestal is not a bad assumption in the ITER-relevant low collisionality regime. On the other hand, the pressure gradient decreases and the pedestal width increases at high collisionality. The pedestal broadening becomes significant when the pedestal is marginal to be unstable at the high n ballooning mode in the high collisionality regime.

  18. 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.

  19. Boronization effects using deuterated-decaborane (B 10D 14) in JT-60U

    NASA Astrophysics Data System (ADS)

    Nakano, T.; Higashijima, S.; Kubo, H.; Yagyu, J.; Arai, T.; Asakura, N.; Itami, K.

    2003-03-01

    Boronization effects have been systematically investigated using discharges with identical conditions in JT-60U. In 50 shots after boronization using 70 g of B 10D 14, the carbon content decreased due to suppression of the chemical sputtering of carbon tiles while the boron content increased. In contrast to the boron and carbon contents, the oxygen content gradually increased from 0.7% to 1.3% in 500 shots. Continual boronization using 10-20 g of B 10D 14 every 200 shots successfully kept the oxygen content less than 1.0%. However, the durability of boronization using 20 g of B 10D 14 is much shorter than that of boronization using 70 g after vacuum vessel ventilation. Due to the reduction of the carbon and oxygen contents, Zeff in 50 shots after boronization lies in the lowest range of the database.

  20. Development of a Real-time Modulation Control System on the JT-60U ECRF System

    SciTech Connect

    Kobayashi, T.; Isayama, A.; Terakado, M.; Sato, F.; Suzuki, S.; Hiranai, S.; Shibayama, M.; Moriyama, S.

    2009-11-26

    A real-time modulation control system was developed for studying the effectiveness of modulated Electron Cyclotron Current Drive (ECCD) on the stabilization of Neoclassical Tearing Modes (NTMs). The phase and duty cycle tracking was enabled with high accuracy even if the NTM frequency varied during ECCD. A characteristic of an anode voltage modulation for modulating the gyrotron oscillation that caused the time variation of the phase and duty cycle was also taking into account. It was shown that the phase and duty cycle could be kept the target values within 50 ms even if the frequency varied by 1 kHz/s or higher at a frequency of around 5 kHz. Then, NTM stabilization experiments with modulated ECCD for m/n = 2/1 NTM was successfully performed in JT-60U.

  1. 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.

  2. Loss of fast tritons in JT-6OU reversed magnetic shear discharges

    NASA Astrophysics Data System (ADS)

    Tobita, K.; Harano, H.; Nishitani, T.; Fujita, T.; Tani, K.; Oikawa, T.; Shirai, H.; Kusama, Y.

    1997-11-01

    In reversed magnetic sheaf-plasmas, fast ion confinement is anticipated to deteriorate because of a weak poloidal magnetic field in the core. In fact, in experiments at JT-6OU considerable depletion of triton burnup in reversed magnetic shear has been observed, compared with normal (positive) magnetic shear. The experimental triton burnup in the reversed shear was 11 to 39% of that expected, while that in the normal shear was 64 to 87%. Here, the expected burnup is based on one dimensional (1-D) calculations that assume classical slowing down and no diffusion of fast tritons. Orbit following Monte Carlo simulations, which treat finite orbit effects and ripple transport processes properly, match the experimental depletion and indicate that ripple loss is responsible for the enhanced triton loss in reversed shear operations. The results raise concerns about serious megaelectronvolt ion loss in reversed shear operations in steady state tokamak reactors

  3. Simulation Study on the ITB Formation during LHCD in JT-60U

    NASA Astrophysics Data System (ADS)

    Cui, Zheng-ying; Osamu, Naito; Takeshi, Fukudai; Hiroshi, Shirai; Yoshitaka, Ikeda; Kenkichi, Ushigusa

    2002-04-01

    A transport simulation has been done by using a 1.5D time dependent transport code to reproduce a formation of the ITB on electron temperature profile during the long pulse LHCD in JT-60U tokamak. The transport coefficients were assumed to reduce with a reversed magnetic shear and the LH driven current profile was evaluated by fitting dynamic change in the measured current profile. The gradual increase in the central electron temperature could be explained by the change in the current profile during LHCD in the present simulation model. The estimated LH-driven current profile by the transport code analysis shows a finite current density at the plasma center. Analysis of transport simulation suggests some mechanisms for broadening the LH-driven current profile at the central region of the plasma.

  4. 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.

  5. Launcher heat load on high power LHCD experiments in JT-60U

    NASA Astrophysics Data System (ADS)

    Naito, O.; Ikeda, Y.; Seki, M.; Ide, S.; Kondoh, T.; Ushigusa, K.

    1995-04-01

    Heat loads on a lower hybrid wave launcher as well as on the first wall during high power auxiliary heating and their origin are investigated. It is found that the heat load on the launcher is moderate during injection of lower hybrid wave into a ohmic plasma. However, it is significantly enhanced by the existence of high energy banana-trapped particles and localized near the equatorial plane. In JT-60U, lower hybrid wave can be coupled to the plasma at a launcher-plasma distance of ˜ 20 cm without any significant heat load on the launcher grill. Nevertheless, the heat load due to banana-orbit particles may impose a constraint on the position of a launcher.

  6. Numerical analyses of JT-60SA scenarios with the COREDIV code

    NASA Astrophysics Data System (ADS)

    Zagórski, R.; Giruzzi, G.; Gała¸zka, K.; Ivanova-Stanik, I.; Romanelli, M.; Stȩpniewski, W.

    2016-01-01

    JT-60SA design scenarios have been analyzed with the help of the self-consistent core-edge COREDIV code, with the aim to assess the influence of impurities on the plasma parameters and tokamak performance. In particular, the reduction of divertor target power load due to radiation of sputtered and externally seeded impurities has been investigated. For all scenarios considered, the gradual replacement of carbon by low Z seeding impurity (N, Ne) is observed as the gas influx increases. For high auxiliary power and low density scenarios, the carbon and seeding impurity radiation does not effectively reduce power to plate. Consequently, results with very high {{Z}\\text{eff}} (about 6–8) and impurity concentrations (>9%) are observed. For these scenarios, seeding of the high Z impurity like krypton seems to be more appropriate, in particular when the plasma density is increased.

  7. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. The H-mode pedestal, ELMs and TF ripple effects in JT-60U/JET dimensionless identity experiments

    NASA Astrophysics Data System (ADS)

    Saibene, G.; Oyama, N.; Lnnroth, J.; Andrew, Y.; de la Luna, E.; Giroud, C.; Huysmans, G. T. A.; Kamada, Y.; Kempenaars, M. A. H.; Loarte, A.; McDonald, D.; Nave, M. M. F.; Meiggs, A.; Parail, V.; Sartori, R.; Sharapov, S.; Stober, J.; Suzuki, T.; Takechi, M.; Toi, K.; Urano, H.

    2007-08-01

    This paper summarizes results of dimensionless identity experiments in JT-60U and JET, aimed at the comparison of the H-mode pedestal and ELM behaviour in the two devices. Given their similar size, dimensionless matched plasmas are also similar in their dimensional parameters (in particular, the plasma minor radius a is the same in JET and JT-60U). Power and density scans were carried out at two values of Ip, providing a q scan (q95 = 3.1 and 5.1) with fixed (and matched) toroidal field. Contrary to initial expectations, a dimensionless match between the two devices was quite difficult to achieve. In general, pped in JT-60U is lower than in JET and, at low q, the pedestal pressure of JT-60U with a Type I ELMy edge is matched in JET only in the Type III ELM regime. At q95 = 5.1, a dimensionless match in ?*, ?* and ?p,ped is obtained with Type I ELMs, but only with low power JET H-modes. These results motivated a closer investigation of experimental conditions in the two devices, to identify possible 'hidden' physics that prevents obtaining a good match of pedestal values over a large range of plasmas parameters. Ripple-induced ion losses of the medium bore plasma used in JT-60U for the similarity experiments are identified as the main difference with JET. The magnitude of the JT-60U ripple losses is sufficient to induce counter-toroidal rotation in co-injected plasma. The influence of ripple losses was demonstrated at q95 = 5.1: reducing ripple losses by ap2 (from 4.3 to 1.9 MW) by replacing positive with negative neutral beam injection at approximately constant Pin resulted in an increased pped in JT-60U, providing a good match to full power JET H-modes. At the same time, the counter-toroidal rotation decreased. Physics mechanisms relating ripple losses to pedestal performance are not yet identified, and the possible role of velocity shear in the pedestal stability, as well as the possible influence of ripple on thermal ion transport are briefly discussed. Toroidal rotation of the ITER reference inductive Q = 10 H-mode is predicted to be rather low, of the order of ~1/10 of the frequency of typical JET H-modes. Nonetheless, fast ion ripple losses in that scenario are also predicted to be negligible (<~1%), and therefore plasma toroidal rotation slow-down or ripple-induced counter-rotation should not affect pedestal parameters and stability in ITER. Finally, the possible effect of ripple on thermal transport may deserve more attention in future experiments and modelling, since the ripple magnitude of ITER is intermediate between that of JET and JT-60U.

  11. 76 FR 77107 - Airworthiness Directives; Pratt & Whitney Corp. (PW) JT9D-7R4H1 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ...We are adopting a new airworthiness directive (AD) for all PW JT9D-7R4H1 turbofan engines. This AD was prompted by reports of cracks in five high-pressure compressor (HPC) shafts. This AD requires removing certain HPC shafts before their certified life limits and establishes a new, lower life-limit for these parts. We are issuing this AD to correct the unsafe condition on these...

  12. 76 FR 41144 - Airworthiness Directives; Pratt & Whitney Corp. (PW) JT9D-7R4H1 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ...We propose to adopt a new airworthiness directive (AD) for all PW JT9D-7R4H1 turbofan engines. This proposed AD would require removing certain high-pressure compressor (HPC) shafts before their certified life limits, and establishes a new, lower life-limit for these parts. This proposed AD was prompted by reports of cracks in five HPC shafts. We are proposing this AD to correct the unsafe......

  13. 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.

  14. Impact of arcing on carbon and tungsten: from the observations in JT-60U, LHD and NAGDIS-II

    NASA Astrophysics Data System (ADS)

    Kajita, Shin; Fukumoto, Masakatsu; Tokitani, Masayuki; Nakano, Tomohide; Noiri, Yasuyuki; Ohno, Noriyasu; Masuzaki, Suguru; Takamura, Shuichi; Yoshida, Naoaki; Ueda, Yoshio

    2013-05-01

    Arcing is a long-standing plasma-surface interaction issue, and the issue is currently being revived. This paper assesses the impact of arcing in fusion devices based on the observations in JT-60U, the Large Helical Device (LHD) and the linear divertor simulator NAGDIS-II. To investigate the first initiation process of arcing, field emission currents from several tungsten samples are measured. It is shown that the field emission current increases significantly after tungsten is exposed to helium plasmas. A postmortem analysis of JT-60U tiles reveals that arcing phenomena occurred on carbon baffle plates inside the vacuum vessel in JT-60U. From the observation of the arc trails recorded on the baffle plate, the amount of eroded materials is discussed. The arcing seems to occur frequently on the inner baffles rather than the outer baffles. From LHD, it is shown that the arcing can be initiated on nanostructured tungsten even without transient events. The erosion of tungsten by arcing will become an important issue in a fusion reactor, where helium fluence is significantly increased. From the experiments in NAGDIS-II, it is shown that arcing can be initiated even without transient heat load when the target voltage is low enough, e.g. -500 V. Frequent initiation of arcing annihilates the nanostructure growth due to helium plasma irradiation on the surface.

  15. Overview of JT-60U progress towards steady-state advanced tokamak

    NASA Astrophysics Data System (ADS)

    Ide, S.; JT-60 Team

    2005-10-01

    Recent experimental results from steady-state advanced tokamak (AT) research on JT-60U are presented with emphasis on time scales longer in comparison with the characteristic time scales in plasmas. To achieve this, modification of the controls for the operation, heating and diagnostics systems have been carried out. As a result, ~60 s current flat top and a ~30 s H-mode are obtained. The long pulse modification has opened a door into a new domain for JT-60U. High normalized beta (βN) of 2.3 is maintained for 22.3 s and 2.5 for 16.5 s in a high-βp H-mode plasma. A standard ELMy H-mode plasma has also been extended and changes in the wall recycling on the longer time scale have been unveiled. The development and investigation of plasmas relevant to AT operation have been continued in long discharges as well as in discharges where higher NB power is available (<=10 s). Higher βN (~3) is maintained for 6.2 s in a high-βp H-mode plasma. High bootstrap current fraction (fBS) of ~75% is sustained for 7.4 s in a reversed shear plasma. Neo-classical tearing mode (NTM) suppression by localized ECCD is found to be more effective with ECRF injection preceding the mode saturation. The mode is suppressed with less power compared to the injection after the mode saturates. The domain of the NTM suppression experiments is extended to the high-βN regime, and the effectiveness of m/n = 3/2 mode suppression by ECCD is demonstrated at βN ~ 2.5-3. Genuine tokamak plasma start up without a central solenoid is demonstrated. In a current hole region, it is shown that no scheme drives current in any direction. Detailed measurement of energetic ions in both space and energy showed dynamic change in the energetic ion profile due to collective instabilities. The impact of toroidal plasma rotation on ELM behaviour is clarified in the grassy ELM and QH domains. Retention of hydrogen isotopes in the divertor tiles is analysed.

  16. Long term hydrogen retention in the plasma facing carbon tiles of JT-60U

    NASA Astrophysics Data System (ADS)

    Yoshida, Masafumi; Tanabe, Tetsuo; Sugiyama, Kazuyoshi; Hayashi, Takao; Nakano, Tomohide; Yagyu, Junnichi; Miyo, Yasuhiko; Masaki, Kei; Itami, Kiyoshi

    2011-10-01

    In order to investigate how fuel (H + D) retention increases with discharge time, we have measured long term H + D retention of the carbon tiles exposed to plasmas in JT-60U by TDS and SEM. The H + D retention in the re-deposited carbon layers on divertor tiles linearly increases with the thickness of the re-deposited layers with a constant hydrogen concentration of (H + D)/C 0.013. The C-deposition and H + D retention rates are in the order of 1 10 20 C/m 2/s and 3.8 10 18 H + D atoms/m 2/s, respectively. The H + D retentions in the near surface regions of eroded tiles both at outer divertor and outer first wall did not go over 5 10 22 H + D atoms/m 2, suggesting hydrogen saturation at the near surface regions. However, in a little deeper region of the outer first wall tiles, direct implantation of energetic D originated from Neutral Beam Injection (NBI) caused gradual increase of the retention until saturation in the implanted depth.

  17. 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.

  18. Roles of argon seeding in energy confinement and pedestal structure in JT-60U

    NASA Astrophysics Data System (ADS)

    Urano, H.; Nakata, M.; Aiba, N.; Kubo, H.; Honda, M.; Hayashi, N.; Yoshida, M.; Kamada, Y.; the JT-60 Team

    2015-03-01

    The mechanism of improving energy confinement with argon seeding at high density has been investigated in JT-60U. Better confinement is sustained at high density by argon seeding accompanied by higher core and pedestal temperatures. The electron density profiles become flatter with increasing density in conventional H-mode plasmas, whereas peaked density profiles are maintained with argon seeding. Density peaking and dilution effects lower the pedestal density at a given averaged density. The pedestal density in the argon seeded plasmas, which is lower than that in plasmas with deuterium puff, enables the pedestal temperature to be higher, whereas the increase in the pedestal pressure with argon seeding is small. High pedestal temperature is a boundary condition for high core temperature through profile stiffness, which leads to better confinement with argon seeding. The density peaking is a key factor of sustaining better confinement in argon seeded H-mode plasmas. The radiative loss power density is predominantly enhanced in the edge region by argon puff. The role of argon seeding in the pedestal characteristics has also been examined. The pedestal width becomes larger continuously with edge collisionality, but is nearly independent of the presence of argon seeding.

  19. 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).

  20. Pulsed-laser ablation of co-deposits on JT-60 graphite tile

    NASA Astrophysics Data System (ADS)

    Sakawa, Youichi; Watanabe, Daisuke; Shibahara, Takahiro; Sugiyama, Kazuyoshi; Tanabe, Tetsuo

    2007-08-01

    Pulsed laser ablation of the co-deposits on a JT-60 open-divertor tile using the fourth harmonic of a 20 ps-Nd: YAG laser has been investigated. With increasing the laser intensity, three regions, non-ablation region (NAR), weak-ablation region (WAR), and strong-ablation region (SAR) were distinguished. Transition from NAR to WAR and WAR to SAR occurred at the threshold laser intensity for laser ablation and that for strong ionization of carbon atoms, respectively. The ablation accompanied desorption of H 2 and C 2H 2, with minor contribution of other hydrocarbons, while production of H 2O was small. In NAR and WAR the number of the hydrogen desorbed by the laser irradiation was less than that of hydrogen retained in the ablated volume, while in SAR it was much larger, owing to thermal desorption of hydrogen gas from the region surrounding the ablated volume. For the ablative removal of hydrogen isotopes, SAR is more desirable because of higher removal efficiency and less production of hydrocarbons.

  1. Impurity control by boronization and optimization of the wall temperature in JT-60U

    NASA Astrophysics Data System (ADS)

    Nakano, T.; Higashijima, S.; Kubo, H.; Sugie, T.; Asakura, N.; Takenaga, H.; Itami, K.

    2001-10-01

    In JT-60U, boronization using deuterated decaborane has been applied to suppress oxygen production. Boronization decreased the oxygen content in the core plasma from ~ 3% to ~ 0.5%. The oxygen content of ~ 0.5% was kept by additional boronization about every 100 shots. By lowering the vessel temperature from 540 K to 420 K, chemical sputtering yield decreased by ~ 40% at the carbon divertor plates. For hydrogen plasmas, the carbon content reduced from 3.1% to 1.8% in L-mode discharges with NB heating power of 13 MW ,and from 2.4% to 1.7% in reversed shear discharges. For deuterium plasmas, however, the carbon content did not depend on the vessel temperature. The different dependence of the carbon content on the vessel temperature is considered to be due to isotopic difference between chemical and physical sputtering yield. The effects of boronization and the vessel temperature will be discussed based on correlation between impurity content and impurity influx from the divertor plates and the first walls.

  2. Investigation of performance deterioration of the CF6/JT9D high bypass ratio turbofan engines

    NASA Technical Reports Server (NTRS)

    Ziemianski, J. A.

    1981-01-01

    The extent and magnitude of performance deterioration of the Pratt and Whitney JT9D, and the General Electric CF6 engine models is presented. Overall engine and contributing module performance deterioration with respect to flight cycles and/or time are analyzed. The overall engine performance deterioration analyses are based on data obtained from historical records, special engine tests, and tests for specific effects. Hardware inspection data from overhaul shops and special module tests are the basis for the modular performance deterioration data used in the analyses. Various damage mechanisms such as seal rubs, erosion, surface roughness and thermal distortion, and how they contribute to performance deterioration are included in the modular analyses. Results indicate that early performance deterioration occurring within the first few flights of these engines is less than 1 percent in cruise specific fuel consumption (SFC), that it is event oriented, and that it is the result of increased blade tip clearances. This performance deterioration gradually increases to about 2.5 to 3.0 percent (including the initial short term deterioration) after 2500 to 3000 flights where increased blade tip clearances, airfoil quality degradation, and thermal distortion are the contributing causes.

  3. 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.

  4. 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.

  5. Edge-core relationship of ELMy H-mode plasmas in JT-60U

    NASA Astrophysics Data System (ADS)

    Urano, H.; Kamada, Y.; Shirai, H.; Takizuka, T.; Kubo, H.; Takenaga, H.; Miura, Y.; Hatae, T.; Fukuda, T.

    2002-05-01

    The effects of the conductive heat flow on the energy transport concerning the temperature profile similarity have been analysed for (\\ref{eq1}) high triangularity and (2) Ar seeded ELMy H-mode plasmas on JT-60U. The temperature profiles of the plasma core on the logarithmic plot are shape preserving and independent of the varying pedestal height. As the conductive heat flux increases, the effective heat conductivity, ?eff, adjusts itself to sustain a constant ?(ln Ti) in the plasma core. In high triangularity discharges, highly improved energy confinement quality accompanied by high core temperature is obtained when the boundary temperature rises with an increase in ?pol. On the other hand, the peaked density profiles in Ar seeded discharges allow the temperature at the pedestal shoulder to be higher relative to the cases without Ar gas injection, and the core temperature is also raised. As the conductive heat flux is reduced by increasing the radiation loss flux in Ar seeded H-mode plasmas, ?eff decreases with a similar ?(ln Ti) of the plasma core in the case without Ar gas injection. Improved particle confinement due to Ar gas puff raises the achievable density and contributes to the reduction in ?eff.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Enhanced performance and control issues in JT-60U long pulse discharges

    NASA Astrophysics Data System (ADS)

    Sakamoto, Y.; JT-60 Team

    2005-12-01

    Recent experimental results are reported on control issues involved in long timescales and enhanced performance in JT-60U. The control issues in neoclassical tearing mode (NTM) suppression in the weak shear plasma regime include background optimization through decreasing βp(Lq/Lp) at the rational surface and active stabilization of NTMs using ECCD. By optimizing βp(Lq/Lp), a condition of βN ~ 2.5 was sustained for 10 times the current profile relaxation time and one of βN ~ 2.4 with qmin ~ 1.5 was sustained for 2.8 times the current profile relaxation time, with nearly full non-inductive current drive. In addition, a condition of βN ~ 3 was sustained for 5.5 s through stabilization of NTMs using ECCD, and an EC driven current nearly equal to the bootstrap current was required for complete stabilization. In the reversed shear plasma regime, the issue is the existence of the steady state solution with a large fBS value. By controlling the pressure gradient at the internal transport barrier through toroidal rotation to avoid the disruption, a large fBS value of approximately 75% was sustained for 2.7 times the current profile relaxation time, with nearly full non-inductive current drive, and a steady-state solution with a large fBS value is confirmed. The control issues for the edge pedestal and edge localized modes (ELMs) are control of the pedestal pressure and the energy loss through ELMs. The pedestal pressure increases by >40% through the change in toroidal rotation. The type of ELM can be controlled by toroidal rotation from type-I to grassy.

  11. Stabilization of neoclassical tearing mode by ECCD and its evolution simulation on JT-60U tokamak

    NASA Astrophysics Data System (ADS)

    Nagasaki, K.; Isayama, A.; Hayashi, N.; Ozeki, T.; Takechi, M.; Oyama, N.; Ide, S.; Yamamoto, S.; JT-60 Team

    2005-12-01

    Stabilization of an m = 3/n = 2 neoclassical tearing mode (NTM) by a local electron cyclotron current drive (ECCD) has been studied in high βp ELMy H-mode plasmas in the JT-60U tokamak. In the stabilization experiment, the electron cyclotron (EC) injection timing is scanned from the 'before mode onset' phase (preemptive ECCD) to the mode saturation phase (late ECCD). It has been demonstrated that the ECCD is more effective when it is applied before the mode onset and the critical timing for effective ECCD is related to the mode excitation phase. The EC power to prevent the 3/2 NTM excitation by preemptive ECCD is lower by about 20% compared with complete stabilization by late ECCD. Even when the 3/2 NTM is excited, the stabilization effect is stronger than for late ECCD. For a high performance plasma of the normalized beta, βN = 3.0, the H-factor H89PL improves from 1.9 to 2.1 when the 3/2 NTM is suppressed. A numerical study has been made based on the modified Rutherford equation coupled with a 1.5D transport code and an EC code. The simulation reproduces well the time evolution of the magnetic island both at the growing and stabilizing phases. The simulation results show that it is important to adjust not only the EC current position but also its width to stabilize the NTM effectively. The reduction of EC power for NTM prevention in experiments for preemptive ECCD can be explained by the increase of the minimum seed island size for NTM excitation. This manuscript is based on the paper EX/7-4 presented at the 20th IAEA Fusion Energy Conference, Vilamoura, Portugal.

  12. Integrated plasma control extending the Advance Tokamak regime in JT-60U

    NASA Astrophysics Data System (ADS)

    Itami, Kiyoshi

    2008-11-01

    In order to realize the economical fusion reactor, high confinement (H98 factor), high normalized beta (?N), high bootstrap current fraction (fBS), i.e. the Advanced Tokamak (AT) plasma must be sustained. In the recent experimental campaigns from November in 2007 to August in 2008, the operational regime and pulse lengths of AT plasmas has been significantly extended and the various control techniques toward steady state both in the core plasmas and in the boundary plasmas were steadily improved in JT-60U. The optimization of the beam heating profile for sustaining ITB and the enhanced wall conditioning successfully extended the high ?N 2.6 for 28 seconds (25 seconds for H98 .3ex>=x 1) in the positive shear (PS) plasma without increase in particle recycling level in the divertor. Because of high G-factor (?N H98/ q95^2) of 0.25, this plasma is relevant for ITER hybrid operation scenario. While the reversed shear (RS) plasma with high fBS and high H98 factor accompanied with the strong ITB is attracting for the ITER advanced operation scenario and DEMO, the safety factor q95< 8 has not been accessible for fBS.3ex>=x 0.7 due to low beta limit in the previous campaigns. In this experimental campaign, the bN limit is significantly improved and ?N 2.7 and fBS 0.9 was achieved at q95 5.3, by utilizing large volume configuration close to the conductive wall for stabilization of RWM. The real-time control for the power exhaust to the divertor was intensely investigated. Total radiation fraction of Prad / Pheat = 0.8-0.9, was maintained continuously up to 13 seconds with H98 = 0.77-0.84 by utilizing radiation feedback for Ar gas seeding.

  13. Numerical Simulation of a High-Brightness Lithium Ion Gun for a Zeeman Polarimetry on JT-60U

    NASA Astrophysics Data System (ADS)

    Kojima, Atsushi; Kamiya, Kensaku; Iguchi, Harukazu; Fujita, Takaaki; Kamada, Yutaka

    A lithium ion gun is under construction for a lithium beam Zeeman polarimetry on JT-60U. The performance of the prototype ion gun has been estimated by the numerical simulation taking the space charge effects into account. The target values of the ion gun are the beam energy of 30 keV, the beam current of 10 mA and the beam divergence angle within 0.13 degrees. The low divergence of 0.13 degrees is required for the geometry of the Zeeman polarimetry on JT-60U where the observation area is 6.5 m away from the neutralizer. The numerical simulation needs to be carried out for the design study because the requirement of the divergence angle is severe for the development of the high-brightness ion gun. The simulation results show the beam loss of 50 % caused by the clash to the electrode such as the cathode and the neutralizer. Moreover, the beam transport efficiency from the neutralizer to the observation area is low due to the broadening of the divergence angle. The total beam efficiency is about 5 %. Extracted beam profile affects the beam focusing and the efficiency. The peaked profile achieves better efficiency than the hollow one. As a result, beam current of 1 mA is obtained at the observation area by the simulation for the prototype ion gun.

  14. 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. PMID:25164379

  15. Collective Thomson scattering based on CO2 laser for ion energy spectrum measurements in JT-60U

    NASA Astrophysics Data System (ADS)

    Kondoh, T.; Miura, Y.; Lee, S.; Richards, R. K.; Hutchinson, D. P.; Bennett, C. A.

    2003-03-01

    A collective Thomson scattering (CTS) diagnostic system based on a pulsed CO2 laser has been developed and brought into operation to establish a measurement technique for ion temperature and the energy spectrum of fast ions. The pulsed CO2 laser (wavelength 10.6 ?m, beam energy 15 J, pulse width 1 ?s) and a heterodyne receiver were installed on the JT-60U tokamak. Calculation of the scattered power spectrum from high temperature plasma in JT-60U shows that a good signal-to-noise value is expected for the bulk-ion temperature measurement. Calibration of the heterodyne receiver system has been carried out using a large area (1212 cm2) blackbody radiation source. Commissioning of the CTS system by injecting the CO2 laser into the plasmas has been accomplished. However, a scattered signal has not yet been detected due to electrical noise originating from the pulsed lasers discharge and stray signal coming from mode impurities in the pulsed laser. After the electrical and stray light reduction, ion temperature will be evaluated from the scattered spectrum using the CTS system.

  16. Acceleration of 500 keV Negative Ion Beams By Tuning Vacuum Insulation Distance On JT-60 Negative Ion Source

    SciTech Connect

    Kojima, A.; Hanada, M.; Tanaka, Y.; Taniguchi, M.; Kashiwagi, M.; Inoue, T.; Umeda, N.; Watanabe, K.; Tobari, H.; Kobayashi, S.; Yamano, Y.; Grisham, L. R.

    2011-09-26

    Acceleration of a 500 keV beam up to 2.8 A has been achieved on a JT-60U negative ion source with a three-stage accelerator by overcoming low voltage holding which is one of the critical issues for realization of the JT-60SA ion source. In order to improve the voltage holding, preliminary voltage holding tests with small-size grids with uniform and locally intense electric fields were carried out, and suggested that the voltage holding was degraded by both the size and local electric field effects. Therefore, the local electric field was reduced by tuning gap lengths between the large size grids and grid support structures of the accelerator. Moreover, a beam radiation shield which limited extension of the minimum gap length was also optimized so as to reduce the local electric field while maintaining the shielding effect. These modifications were based on the experiment results, and significantly increased the voltage holding from <150 kV/stage for the original configuration to 200 kV/stage. These techniques for improvement of voltage holding should also be applicable to other large ion sources accelerators such as those for ITER.

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2005-11-01

    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 (0.680.540.2m) 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.

  20. 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.

  1. 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-mounted error sensors and passive control techniques is an effective means of reducing radiated noise from turbofan engines. Strategic selection of the location of the error transducers is shown to be effective for reducing the radiation towards particular directions in the farfield. An analytical model is used to predict the behavior of the control system and to guide the experimental design configurations, and the analytical results presented show good agreement with the experimentally observed results.

  2. 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.

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

    NASA Astrophysics Data System (ADS)

    Gupta, Prabhat Kumar; Rabehl, Roger

    2014-07-01

    Fermilab Vertical Test Stand-1 (VTS-1) has been in operation since 2007 for testing superconducting radio frequency (SCRF) cavities at 2 K. This test stand includes a heat exchanger consisting of a single layer; helically wound finned tube, upstream of the J-T valve. A finite difference thermal model has been developed in Engineering Equation Solver (EES) to study the thermal performance of this heat exchanger during refilling of the test stand. The model can predict heat exchanger performance under various other operating conditions and is therefore useful as a design tool for similar heat exchangers in other facilities. The present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have been compared with experimental data gathered from the VTS-1 heat exchanger, and they are in good agreement with the present model.

  4. 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.

  5. 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.

  6. 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.

  7. Anisotropic electron temperature measurements without knowing the spectral transmissivity for a JT-60SA Thomson scattering diagnostic

    SciTech Connect

    Tojo, H.; Hatae, T.; Yatsuka, E.; Itami, K.

    2012-10-15

    This paper focuses on a method for measuring the electron temperature (T{sub e}) without knowing the transmissivity using Thomson scattering diagnostic with a double-pass scattering system. Application of this method for measuring the anisotropic T{sub e}, i.e., the T{sub e} in the directions parallel (T{sub e Double-Vertical-Line Double-Vertical-Line }) and perpendicular (T{sub e Up-Tack }) to the magnetic field, is proposed. Simulations based on the designed parameters for a JT-60SA indicate the feasibility of the measurements except in certain T{sub e} ranges, e.g., T{sub e Double-Vertical-Line Double-Vertical-Line }{approx} 3.5T{sub e Up-Tack} at 120 Degree-Sign of the scattering angle.

  8. Role of convective amplification of n = 1 energetic particle modes for N-NB ion dynamics in JT-60U

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    The hybrid code MEGA is used to simulate an abrupt large-amplitude event (ALE) in JT-60U shot E039672 that was strongly driven by a pair of negative-ion-based neutral beams (N-NBs). This configuration is known to be unstable to energetic particle modes (EPMs) with toroidal mode number n = 1. The purpose of this study is to look for a threshold with respect to the on-axis fast ion beta value, ?h0, beyond which the EPM undergoes convective amplification (CA) and causes significant fast ion transport. This is motivated by the hypothesis that such a threshold may work as a trigger mechanism for relaxation events, such as ALE. In order to facilitate quantitative comparisons with the experiment, a realistic geometry and bulk pressure is used. Furthermore, MEGA is initialized with a fast ion distribution computed for JT-60U by an orbit-following Monte-Carlo code, and a passive vacuum region allows particles to travel without encountering artificial loss boundaries. Consistently with the experiment, the simulation predicts a burst time of about 0.3 ms and peak magnetic fluctuation levels around ?B?/B < 10-3 at the plasma boundary. As ?h0 is increased, a gradual increase in the CA of the EPM and in the convective transport of both resonant and nonresonant particles is found. The absence of a sharp transition between low- and high-amplitude fluctuations leads to the conclusion that the onset of CA does not suffice as a trigger mechanism for ALE.

  9. 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.

  10. Engineering study of the neutral beam and rf heating systems for DIII-D, MFTF-B, JET, JT-60 and TFTR

    SciTech Connect

    Lindquist, W.B.; Staten, S.H.

    1987-01-01

    An engineering study was performed on the rf and neutral beam heating systems implemented for DIII-D, MFTF-B, JET, JT-60 and TFTR. Areas covered include: methodology used to implement the systems, technology, cost, schedule, performance, problems encountered and lessons learned. Systems are compared and contrasted in the areas studied. Summary statements were made on common problems and lessons learned. 3 refs., 6 tabs.

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

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

    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.

  12. Dynamics of low-n shear Alfvn modes driven by energetic N-NB ions in JT-60U

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    Dynamics of fast ions and shear Alfvn waves are simulated using MEGA, a global nonlinear hybrid code. The scenario considered is based on JT-60U shot E039672, driven by strong negative-ion-based neutral beams (N-NB), just before the onset of a so-called abrupt large event (ALE). It is found that modes with toroidal mode numbers n = 2, 3, 4 can be destabilized, besides the n = 1 mode studied previously. The properties of the modes with n > 1 are sensitive to the value of the plasma beta and the form of the fast ion distribution, so simulation conditions are set up as realistically as presently possible. When the fast ion drive exceeds a certain threshold, the n = 3 mode is enhanced through a convective amplification process while following fast ions were displaced either by the n = 3 mode itself or by the n = 1 mode. The fast ion transport in several cases, simulated with single- or multiple-n modes, is analysed and implications of the results for the explanation of ALEs are discussed.

  13. Surface discharge related properties of fiberglass reinforced plastic insulator for use in neutral beam injector of JT-60Ua)

    NASA Astrophysics Data System (ADS)

    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 500keV 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.

  14. Zeeman polarimetry measurement for edge current density determination using Li-beam probe on JT-60U.

    PubMed

    Kamiya, K; Fujita, T; Kojima, A; Kubo, H

    2010-03-01

    Zeeman polarimetry system using Li-beam probe has been developed for the edge current density measurement in the JT-60U tokamak, which measures the polarization angle alpha (related to the pitch angle of the magnetic field) by means of photoelastic modulators, etalons, and phase sensitive detection using digital lock-in amplifiers with the accuracy in the alpha of Delta alpha approximately 0.1 degrees. The diagnostic has 20-channel viewing chords covering the plasma peripheral region of normalized minor radius r/a approximately 0.8-1 with a spatial resolution of up to approximately 1 cm. Li-beam injection with beam current of up to approximately 5 mA has been achieved. A new tuning method of the wavelength for the etalon has been demonstrated, scanning the beam acceleration voltage and keeping a beam current constant during a single shot. The peak wavelength of the etalon is adjusted in the direction to both blue- and redshifts by changing the angle of incidence and increasing the temperature, respectively. Time evolution of the edge current density profile has been determined for the current ramp experiment in the Ohmically heated discharges. In addition, the edge current density profile with the local peak of j(ped) approximately 0.15-0.25 MA/m(2) at r/a approximately 0.9 has been identified in the H-mode plasma, which is correlated with large pressure gradient in the pedestal region. PMID:20370173

  15. Zeeman polarimetry measurement for edge current density determination using Li-beam probe on JT-60U

    SciTech Connect

    Kamiya, K.; Fujita, T.; Kojima, A.; Kubo, H.

    2010-03-15

    Zeeman polarimetry system using Li-beam probe has been developed for the edge current density measurement in the JT-60U tokamak, which measures the polarization angle {alpha} (related to the pitch angle of the magnetic field) by means of photoelastic modulators, etalons, and phase sensitive detection using digital lock-in amplifiers with the accuracy in the {alpha} of {Delta}{alpha}{approx}0.1 deg. The diagnostic has 20-channel viewing chords covering the plasma peripheral region of normalized minor radius r/a{approx}0.8-1 with a spatial resolution of up to {approx}1 cm. Li-beam injection with beam current of up to {approx}5 mA has been achieved. A new tuning method of the wavelength for the etalon has been demonstrated, scanning the beam acceleration voltage and keeping a beam current constant during a single shot. The peak wavelength of the etalon is adjusted in the direction to both blue- and redshifts by changing the angle of incidence and increasing the temperature, respectively. Time evolution of the edge current density profile has been determined for the current ramp experiment in the Ohmically heated discharges. In addition, the edge current density profile with the local peak of j{sub ped}{approx}0.15-0.25 MA/m{sup 2} at r/a{approx}0.9 has been identified in the H-mode plasma, which is correlated with large pressure gradient in the pedestal region.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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.

  1. 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.

  2. 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.

  3. 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.

  4. Integrated modelling of toroidal rotation with the 3D non-local drift-kinetic code and boundary models for JT-60U analyses and predictive simulations

    NASA Astrophysics Data System (ADS)

    Honda, M.; Satake, S.; Suzuki, Y.; Yoshida, M.; Hayashi, N.; Kamiya, K.; Matsuyama, A.; Shinohara, K.; Matsunaga, G.; Nakata, M.; Ide, S.; Urano, H.

    2015-07-01

    The integrated simulation framework for toroidal momentum transport is developed, which self-consistently calculates the neoclassical toroidal viscosity (NTV), the radial electric field {{E}r} and the resultant toroidal rotation {{V}?} together with the scrape-off-layer (SOL) physics-based boundary model. The coupling of three codes, the 1.5D transport code TOPICS, the three-dimensional (3D) equilibrium code VMEC and the 3D ? f drift-kinetic equation solver FORTEC-3D, makes it possible to calculate the NTV due to the non-axisymmetric perturbed magnetic field caused by toroidal field coils. Analyses reveal that the NTV significantly influences {{V}?} in JT-60U and {{E}r} holds the key to determine the NTV profile. The sensitivity of the {{V}?} profile to the boundary rotation necessitates a boundary condition modelling for toroidal momentum. Owing to the high-resolution measurement system in JT-60U, the {{E}r} gradient is found to be virtually zero at the separatrix regardless of toroidal rotation velocities. Focusing on {{E}r} , the boundary model of toroidal momentum is developed in conjunction with the SOL/divertor plasma code D5PM. This modelling realizes self-consistent predictive simulations for operation scenario development in ITER.

  5. Development of an extended thermo-hydraulic simulation tool for fusion magnet design study - Application to the initial versions of JT-60SA TF coils layout

    NASA Astrophysics Data System (ADS)

    Nicollet, S.; Lacroix, B.; Zani, L.; Hertout, P.; Portafaix, Ch.; Villari, R.

    2010-01-01

    In the framework of the EU participation to JT-60SA project [1], a dedicated simulation tool named after Thermo-hydraulic EXtended Tool (TEXTO) was developed at CEA between 2006 and 2007 in order to address in a reliable way the calculation of the magnet conductor temperature increase and temperature margins in different operating conditions. The simulation process is based on three different codes, addressing each specific aspects (MCNP for the 3D nuclear heat calculation, TRAPS for magnetic field, ANSYS for 2D transverse thermal contribution of coil casing), which finally stand as input for the well established code GANDALF (with transient helium properties). Both steady-state operating and disruption transient regimes can be studied with this process and a first application is performed on the basis of the design and operating conditions available at this time on JT-60SA TF magnets, i.e. the first version of the different design stages. The complete analysis is shown together with the associated proposals for the TF conductor layout that could be derived from these studies.

  6. 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.

  7. Temporal and spatial responses of temperature, density and rotation to electron cyclotron heating in JT-60U

    NASA Astrophysics Data System (ADS)

    Yoshida, M.; Ide, S.; Takenaga, H.; Honda, M.; Urano, H.; Kobayashi, T.; Nakata, M.; Miyato, N.; Kamada, Y.

    2013-08-01

    The temporal and spatial responses of electron channels (the electron density, ne, and the electron temperature, Te) and ion channels (the ion temperature, Ti, and the toroidal rotation velocity, V?) to central electron cyclotron heating (ECH) have been investigated in positive shear H-mode plasmas with a relatively peaked Ti profile and internal transport barrier (ITB) plasmas on JT-60U. Ion temperature decreases with ECH after the increase in the electron temperature in the core region. The time scale of the change in Ti is ?30-60 ms in H-mode plasmas and almost constant in radius. In ITB plasmas, the time scale is shorter around the ITB foot and becomes longer inside the ITB foot. The experimentally measured causality indicates that the decrease in Ti is consistent with the ion temperature gradient critical gradient reduction. This is also verified through a comparison with linear gyrokinetic stability analyses. The electron heat diffusivity increases with ECH in both H-mode and ITB plasmas, correlating to the increase in the ion heat diffusivity. Electron density with a relatively flat ne profile does not decrease with ECH. On the other hand, the electron density with a peaked ne profile decreases with ECH. The flattening of the ne profile is observed after the increase in the electron temperature in the core region. The time scale of the change in ne is about 200-350 ms. Linear gyrokinetic stability analyses imply that the growth rate of the trapped electron modes, which increase outward particle flux, becomes more pronounced during ECH. The counter intrinsic rotation with ECH is identified on H-mode plasmas with a small torque input (BAL-NBI). The counter intrinsic rotation is generated after the increase in the electron temperature and correlates to the change in the electron temperature with ECH around the EC deposition. The radial region where the counter intrinsic rotation is observed is wider than the radial region where the electron temperature varies with ECH. The time scale of the change in the toroidal rotation velocity is about 90-200 ms around the ECH deposition and longer than the time scale of the change in Te and Ti.

  8. 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.; National Institute for Fusion Science, Toki 509-5292 ; 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.

  9. Dynamics of energetic particle driven modes and MHD modes in wall-stabilized high-? 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-? 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.

  10. 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.

  11. Achievement of 500 keV negative ion beam acceleration on JT-60U negative-ion-based neutral beam injector

    NASA Astrophysics Data System (ADS)

    Kojima, A.; Hanada, M.; Tanaka, Y.; Kawai, M.; Akino, N.; Kazawa, M.; Komata, M.; Mogaki, K.; Usui, K.; Sasaki, S.; Kikuchi, K.; Seki, N.; Nemoto, S.; Oshima, K.; Simizu, T.; Kubo, N.; Oasa, K.; Inoue, T.; Watanabe, K.; Taniguchi, M.; Kashiwagi, M.; Tobari, H.; Umeda, N.; Kobayashi, S.; Yamano, Y.; Grisham, L. R.

    2011-08-01

    Hydrogen negative ion beams of 507 keV, 1 A and 486 keV, 2.8 A have been successfully produced in the JT-60U negative ion source with a three-stage accelerator by overcoming a poor voltage holding of the accelerator with large-size grids of ~2 m2. This is the first result of H- beam acceleration up to 500 keV at a high current of over 1 A. In order to improve the voltage holding capability, the breakdown voltages of the large-size grids and small-size electrodes with uniform and locally strong electric fields were examined by changing the gap length. It was found that the voltage holding of the large-size grids was below half of that of the small-size electrodes with a uniform electric field which was used in the design of the accelerator. This degradation was found to be caused by the local electric field concentrations in addition to the size. Based on the results of the voltage holding tests and beam optics calculations, the gap lengths of the large-size grids were tuned to have a capability to sustain 600 kV. As a result, the gap tuning realized stable voltage holding during beam accelerations without significant degradations of the beam optics and stripping loss. These results indicated that stable 500 keV beam accelerations required for JT-60SA are feasible and this gap tuning is also applicable for the design of ITER accelerator.

  12. 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.

  13. Off-axis Fishbone-like Instability and Excitation of the Resistive Wall Mode (RWM) in JT-60U and DIII-D Devices

    NASA Astrophysics Data System (ADS)

    Okabayashi, M.

    2010-11-01

    Advanced tokamak experiments in JT-60U [1] and DIII-D [2] have revealed that in high-beta q(0)>1 plasmas, where the resistive wall modes (RWMs) are predicted to be stable by kinetic effects of energetic particles, plasma rotation and a nearby conducting wall, off-axis fishbone-like instabilities often trigger RWMs. The rapid growth of these RWMs prevents high performance operation. The off-axis fishbone-like instability has some similarities to the classic m/n=1/1 internal fishbone instability in terms of its initial frequency near the energetic ion precession frequency, downward frequency-chirping, and a neutron rate drop of ˜20% during each burst. However, there are several unique non-ideal-MHD features in the off-axis fishbone-like instability. The waveform time behavior has strong non-sinusoidal distortion from the q˜2 area to the edge, synchronized with bursting energetic particle losses, while the plasma rotation is rapidly reduced within a few milliseconds. Based on experimental observations the following hypothesis emerges. In plasmas where rotation and kinetic effects are usually sufficient to stabilize the RWM, energetic particles can drive the fishbone instability of several kHz (larger than the inverse of the resistive wall time constant). The reduction of kinetic stabilization due to the resulting energetic particle loss and rapid decrease of plasma rotation makes the plasma more vulnerable to the near-zero frequency RWM. The impact on RWM stability by the off-axis fishbone with its radial and toroidal distortion of the mode structure is assessed by comparing the JT-60U/DIII-D results with theoretical predictions. 6pt [1] G. Matsunaga et al., Phys. Rev. Lett. 103, 045001. (2009). [2] M. Okabayashi et al., Nucl. Fusion 49 (2009) 125003.

  14. 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.

  15. 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.

  16. Operation and Development of the 500-keV Negative-Ion-Based Neutral Beam Injection System for JT-60U

    SciTech Connect

    Kuriyama, M.; Akino, N.; Ebisawa, N.; Grisham, L.; Honda, A.; Itoh, T.; Kawai, M.; Kazawa, M.; Mogaki, K.; Ohara, Y.; Ohga, T.; Okumura, Y.; Oohara, H.; Umeda, N.; Usui, K.; Watanabe, K.; Yamamoto, M.; Yamamoto, T.

    2002-09-15

    The 500-keV negative-ion based neutral beam injector for JT-60U started operation in 1996. The beam power has been increased gradually through optimizing operation parameters of the ion sources and conquering many troubles in the ion source and power supplies caused by a high voltage break-down in the accelerator. However, some issues remain to be solved concerning the ion source for increasing further the beam power and the beam energy. The most serious issue of them is non-uniformity of source plasma in the arc chamber. Various countermeasures have been implemented to improve the non-uniformity. Some of those countermeasures have been found to be partially effective in reducing the non-uniformity of the source plasma, and as the result the ion source, so far, has accelerated negative-ion beams of 17.4A at 403keV with deuterium and 20A at 360keV with hydrogen against the goal of 22A at 500keV. The neutral beam injection power into the plasma has reached 5.8MW at 400keV with deuterium. Further efforts to reach the target of 10MW at 500keV have been continued.

  17. 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.

  18. 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.

  19. Approach to a window coating problem by {ital in situ} transmission monitoring and laser blow-off cleaning developed in the JT-60U Thomson scattering system

    SciTech Connect

    Yoshida, H.; Naito, O.; Hatae, T.; Nagashima, A.

    1997-01-01

    For solving a window coating problem, an {ital in situ} window transmission monitoring by inferring it precisely from a known attenuation of the deposited film has been developed in the JT-60U Thomson scattering system. Also the practicability of an {ital in situ} window cleaning based on a laser blow-off technique has been investigated extensively. The coated film composition could be guessed to be a resin such as {ital polyacrylonitrile} with a small amount of metals. The existence of chromatic upper limit has been found in the recovered transmission after the blow-off cleaning, which gives systematic errors only of less than 3% to an apparent measurement of both electron density and temperature at 10 keV or less. The attenuation itself is unchanged before and after the laser blow-off cleaning. A complementary use of both methods will provide the Thomson scattering measurement of high T{sub e} plasmas with durable reliability and sufficient precision in the existing tokamaks and the International Thermonuclear Experimental Reactor. {copyright} {ital 1997 American Institute of Physics.}

  20. 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.

  1. Purification and characterization of a novel enzyme, alpha-neoagarooligosaccharide hydrolase (alpha-NAOS hydrolase), from a marine bacterium, Vibrio sp. strain JT0107.

    PubMed Central

    Sugano, Y; Kodama, H; Terada, I; Yamazaki, Y; Noma, M

    1994-01-01

    A novel enzyme, alpha-neoagarooligosaccharide hydrolase (EC 3.2.1.-), which hydrolyzes the alpha-1,3 linkage of neoagarooligosaccharides to yield agaropentaose (O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro-alpha-L-galactopyranosyl (1-->3)-D-galactose], agarotriose [O-beta-D-galactopyranosyl(1-->4)-O-3,6-anhydro- alpha-L-galactopyranosyl (1-->3)-D-galactose], agarobiose [O-beta-D-galactopyranosyl(1-->4)-3,6-anhydro-L-galactose], 3,6-anhydro-L-galactose, and D-galactose was isolated from the marine bacterium Vibrio sp. strain JT0107 and characterized. This enzyme was purified 383-fold from cultured cells by using a combination of ammonium sulfate precipitation, successive anion-exchange column chromatography, gel filtration, and hydroxyapatite chromatography, gel filtration, and hydroxyapatite chromatography. The purified protein gave a single band (M(r), 42,000) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Estimation of the M(r) by the gel filtration method gave a value of 84,000, indicating that the enzyme is dimeric. Amino acid sequence analysis revealed it to have a single N-terminal sequence that has no sequence homology to any other known agarases. The optimum temperature and pH were 30 degrees C and 7.7, respectively. The Km and maximum rate of metabolism for neoagarobiose were 5.37 mM and 92 U/mg of protein, respectively. Images PMID:7961439

  2. Investigations of impurity seeding and radiation control for long-pulse and high-density H-mode plasmas in JT-60U

    NASA Astrophysics Data System (ADS)

    Asakura, N.; Nakano, T.; Oyama, N.; Sakamoto, T.; Matsunaga, G.; Itami, K.

    2009-11-01

    Rseduction of heat loading appropriate for the plasma facing components such as the divertor is crucial for a fusion reactor. Power handling by large radiative power loss has been studied in long pulse ELMy H-mode discharges on JT-60U (?d = 30-35 s). Case 1 is argon (Ar) seeding into standard ELMy H-mode plasmas, where large radiation loss in the confined region of the main plasma caused a change in ELM characteristics from Type-I to Type-III. Case 2 is a combination of Ar and nitrogen (Ne) gas seeding into Type-I ELMy H-mode plasmas with an internal transport barrier (ITB). For case 1, large radiation loss both from the main plasma and from the divertor was produced, and operation of Type-III ELMs was preferable to a reduction in ELM energy loss fraction (WELM/Wdia) to 0.15%. Both transient and steady-state heat loadings were reduced. Relatively good energy confinement (HH98y2 = 0.87 - 0.75) with large frad (Prad/Pabs > 0.8) and divertor plasma detachment was sustained continuously for 13.5 s. For case 2, with reduced Ar seeding to the main plasma and increased divertor radiation with Ne seeding, the ELMy H-mode plasma with an ITB had better energy confinement (HH98y2 = 0.95 - 0.8), which was sustained continuously for 12 s. The radiated power was increased primarily in the divertor ( f_{rad}^{div} =0.46\\--0.72 ), which was produced both by seeded Ne ions and by carbon influx due to transient (ELM) and steady-state heat loadings in the attached divertor. Reduction in the heat loading was not enough, thus enhancement of the radiated power in the divertor will be necessary for the formation of the divertor detachment.

  3. The results of low-speed wind tunnel tests to investigate the effects of the NASA refan JT8D engine nacelles on the stability and control characteristics of the Boeing 727-200

    NASA Technical Reports Server (NTRS)

    Shirkey, M. D.

    1973-01-01

    The results from two low-speed wind tunnel tests of the Boeing 727-200 airplane as configured with the NASA refan JT8D-109 turbofan engines are presented. The objective of these tests was to determine the effects of the refan installation on the low-speed stability and control characteristics of the 727 airplane. Four side nacelle locations were tested to insure that aerodynamic interactions of the nacelles and empennage would be optimized. The optimum location was judged to be the same as that of the production JT8D-9 engines; the current production engine mounts can be used for this location. Some small changes in the basic airplane characteristics are attributable to the refan nacelles. The flaps up longitudinal and lateral-directional stability are both slightly increased for low angles of attack and sideslip respectively. The longitudinal stability at stall is improved for both the flaps up and landing flap configurations. The high attitude characteristics of the basic airplane are not significantly altered by the refan nacelle installation. Directional control capability is not affected by the refan nacelles.

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

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Isayama, A.; Ide, S.; Fujita, T.; Oikawa, T.; Sakata, S.; Sueoka, M.; Hosoyama, H.; JT-60 Team

    2005-09-01

    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 (ρCD) by controlling the parallel refractive index N∥ of LH waves through control of phase difference (Δφ) 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 ρCD through Δφ 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)˜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 βN˜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 level, ECCD before the mode onset was more effective than that after mode saturation.

  5. 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 level, ECCD before the mode onset was more effective than that after mode saturation.

  6. 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.

  7. Exhaust emissions characteristics and variability for Pratt and Whitney JT8D-7A gas turbine engines subjected to major overhaul and repair. Final report Nov 1978-Feb 1979

    SciTech Connect

    Becker, E.E.; Frings, G.; Cavage, W.C.

    1980-09-01

    Seven Pratt and Whitney Aircraft (PWA) JT8D-7A turbofan engines were tested at Kennedy International Airport, New York, to evaluate exhaust emissions characteristics and data variability after overhaul. The measured data show that the engines tested did not meet the Environmental Protection Agency (EPA) emission standards. A comparison of the measured data, obtained from the seven overhauled engines evaluated under this program, with new engine data obtained from PWA show that there is a great deal of similarity between the two sets of data. Differences shown in this report between new engine and overhauled engine data are due to the quantity of the engines sampled; the new engine data represent a larger sample size. Satisfactory data can be measured by using the test procedures, instrumentation, and equipment defined in this report.

  8. The results of a low speed wind tunnel test to investigate the effects of installing refan JT8D engines on the McDonnell Douglas DC-9-30

    NASA Technical Reports Server (NTRS)

    Chrisenberry, H. E.; Doss, P. G.; Kressly, A. E.; Prichard, R. D.; Thorndike, C. S.

    1973-01-01

    A low speed wind tunnel test was conducted to assess the effects of the larger JT8D refan nacelles on the stability and control characteristics of the DC-9-30, with emphasis on the deep stall regime. Deep stall pitching moment and elevator hinge moment data, and low angle of attack tail-on and tail-off pitching moment data are presented. The refan nacelle was tested in conjunction with various pylons of reduced span relative to the production DC-9-30 pylon. Also, a horizontal tail that was larger than the production tail was tested. The data show that the refan installation has a small detrimental effect on the DC-9-30 deep stall recovery capability, that recovery characteristics are essentially independent of pylon span, and that the larger horizontal tail significantly increases recovery margins. The deep stall characteristics with the refan installation, within the range of pylon spans tested, are acceptable with no additional design changes anticipated.

  9. 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.

  10. Boundary condition for toroidal plasma flow imposed at the separatrix in high confinement JT-60U plasmas with edge localized modes and the physics process in pedestal structure formation

    NASA Astrophysics Data System (ADS)

    Kamiya, K.; Honda, M.; Urano, H.; Yoshida, M.; Kamada, Y.; Itoh, K.

    2014-12-01

    Modulation charge eXchange recombination spectroscopy measurements with high spatial and temporal resolution have made the evaluation of the toroidal plasma flow of fully stripped carbon impurity ions ( V?C6 + ) in the JT-60U tokamak peripheral region (including, in particular, the separatrix) possible with a better signal-to-noise ratio. By comparing co- and counter-neutral beam injection discharges experimentally, we have identified the boundary condition of V?C6 + and radial electric field shear ( ?Er ) imposed at the separatrix in high confinement (H-mode) plasmas with edge localized modes (ELMs). The V?C6 + value at the separatrix is not fixed at zero but varies with the momentum input direction. On the other hand, the ?Er value is nearly zero (or very weakly positive) at the separatrix. Furthermore, the edge localized mode perturbation does not appear to affect both V?C6 + and ?Er values at the separatrix as strongly as that in the pedestal region. The above experimental findings based on the precise edge measurements have been used to validate a theoretical model and develop a new empirical model. A better understanding of the physical process in the edge transport barrier (ETB) formation due to the sheared Er formation is also discussed.

  11. Boundary condition for toroidal plasma flow imposed at the separatrix in high confinement JT-60U plasmas with edge localized modes and the physics process in pedestal structure formation

    SciTech Connect

    Kamiya, K.; Honda, M.; Urano, H.; Yoshida, M.; Kamada, Y.; Itoh, K.

    2014-12-15

    Modulation charge eXchange recombination spectroscopy measurements with high spatial and temporal resolution have made the evaluation of the toroidal plasma flow of fully stripped carbon impurity ions (V{sub ?}{sup C6+}) in the JT-60U tokamak peripheral region (including, in particular, the separatrix) possible with a better signal-to-noise ratio. By comparing co- and counter-neutral beam injection discharges experimentally, we have identified the boundary condition of V{sub ?}{sup C6+} and radial electric field shear (?E{sub r}) imposed at the separatrix in high confinement (H-mode) plasmas with edge localized modes (ELMs). The V{sub ?}{sup C6+} value at the separatrix is not fixed at zero but varies with the momentum input direction. On the other hand, the ?E{sub r} value is nearly zero (or very weakly positive) at the separatrix. Furthermore, the edge localized mode perturbation does not appear to affect both V{sub ?}{sup C6+} and ?E{sub r} values at the separatrix as strongly as that in the pedestal region. The above experimental findings based on the precise edge measurements have been used to validate a theoretical model and develop a new empirical model. A better understanding of the physical process in the edge transport barrier (ETB) formation due to the sheared E{sub r} formation is also discussed.

  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. JT/LJT connector insert material evaluation

    SciTech Connect

    Baca, J.R.F.

    1991-10-01

    Different insert (insulator) materials are undergoing evaluation to replace the Fiberite E-3938 BE96 material currently used. Also being evaluated is the reconfiguration of the insert and metal shell-edge geometries for the purpose of reducing the alleged interference principally responsible for insert damage.

  14. 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.

  15. Miniature J-T refrigators using adsorption compressors

    NASA Technical Reports Server (NTRS)

    Chan, C. K.; Tward, E.; Elleman, D. D.

    1982-01-01

    More sophisticated cooling systems for the employed detectors will be needed to satisfy the demand for higher resolution and sensitivity of various detectors used in space missions. The design of the cooling system must take into consideration the unique environment of space vehicles. It is pointed out that a deep space vehicle usually has an ample supply of waste heat from a radioisotope thermoelectric generator (RTG) and has a heat sink near zero Kelvin. Passive radiative coolers have been used for cooling temperatures above 90 K. Cooling below 90 K is currently handled by phase changes of solid or liquid cryogens or mechanical refrigeration. However, the weight of the cryogen may be a problem in a long duration space mission. Refrigerators of small cooling capacity are required in many spacecraft applications. For some future NASA missions, a multistage Joule-Thomson refrigerator using adsorption compressors appears particularly attractive. A study is discussed of four different refrigeration stages which use charcoal as the adsorbent. The adsorbed gases are nitrogen, helium, hydrogen, and neon.

  16. Development of a low noise 10K JT. Refrigeration system

    NASA Astrophysics Data System (ADS)

    1986-02-01

    This report summarizes the results of an engineering design program to develop a low noise, closed cycle, Joule-Thomson, microminiature refrigeration system for 10K operation. During this period the effort has been focused on the fabrication of the argon and hydrogen stages of the three stage cooler. A test facility was designed and built which allows one to mount each refrigerator on a separate removable base and to test each in turn. Key to the successful fabrication of the refrigerator is the determination of the proper firing profile for sealing the refrigerator components. Three batches of refrigerators have been built to date, and reasonable yields are now being obtained for the fabrication of these stages. The helium stage has been designed and laid out, and the photomasks prepared. Work has continued on the hydraulically actuated compressor.

  17. Predicting Mothers’ Reports of Children’s Mental Health Three Years after Hurricane Katrin

    PubMed Central

    Lowe, Sarah R.; Godoy, Leandra; Rhodes, Jean E.; Carter, Alice S.

    2012-01-01

    This study explored pathways through which hurricane-related stressors affected the psychological functioning of elementary school aged children who survived Hurricane Katrina. Participants included 184 mothers from the New Orleans area who completed assessments one year pre-disaster (Time 1), and one and three years post-disaster (Time 2 and Time 3, respectively). Mothers rated their children’s behavior problems at Time 3 only (n = 251 children; 53.0% male; Mean age: 10.19 years, SD = 1.68 years). A path analytic model indicated that hurricane-related stressors were associated with increased maternal psychological distress and school mobility in the first post-disaster year, which were associated with higher child internalizing and externalizing symptoms three years post-disaster. Mediation analysis indicated that hurricane-related stressors were associated with child symptoms indirectly, through their impact on maternal psychological distress. Findings underscore the importance of interventions that boost maternal and child mental health and support children through post-disaster school transitions. PMID:23471125

  18. Predicting Mothers' Reports of Children's Mental Health Three Years after Hurricane Katrin.

    PubMed

    Lowe, Sarah R; Godoy, Leandra; Rhodes, Jean E; Carter, Alice S

    2013-01-01

    This study explored pathways through which hurricane-related stressors affected the psychological functioning of elementary school aged children who survived Hurricane Katrina. Participants included 184 mothers from the New Orleans area who completed assessments one year pre-disaster (Time 1), and one and three years post-disaster (Time 2 and Time 3, respectively). Mothers rated their children's behavior problems at Time 3 only (n = 251 children; 53.0% male; Mean age: 10.19 years, SD = 1.68 years). A path analytic model indicated that hurricane-related stressors were associated with increased maternal psychological distress and school mobility in the first post-disaster year, which were associated with higher child internalizing and externalizing symptoms three years post-disaster. Mediation analysis indicated that hurricane-related stressors were associated with child symptoms indirectly, through their impact on maternal psychological distress. Findings underscore the importance of interventions that boost maternal and child mental health and support children through post-disaster school transitions. PMID:23471125

  19. 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.

  20. Control of Growth of Neoclassical Tearing Mode by Central Co-ECCD in JT-60U

    NASA Astrophysics Data System (ADS)

    Isayama, Akihiko; Oyama, Naoyuki; Urano, Hajime; Suzuki, Takahiro; Takechi, Manabu; Ide, Shunsuke; Kamada, Yutaka; Ozeki, Takahisa; Nagasaki, Kazunobu; JT-60 Team, Kazunobu

    Growth of a neoclassical tearing mode (NTM) with a poloidal mode number m = 3 and a toroidal mode number n = 2 has been controlled by electron cyclotron current drive (ECCD) in the same direction as the plasma current (co-ECCD) in the central region away from the NTM island. By using ECCD at a fraction of about 10% of the plasma current, the amplitude of the m/n = 3/2 NTM is limited to about 1/5 of that without ECCD. The frequency spectrum of magnetic perturbations shows that the frequency of the m/n = 3/2 NTM is modulated by a sawtooth crash. The beta value, which is the ratio of the plasma pressure to the magnetic pressure, is higher by 6% than that without ECCD at the same input power. This operational scenario is quite different from that for conventional NTM stabilization in which the ECCD location is accurately adjusted at the mode rational surface and is thus off-axis. This result shows the compatibility of sawtooth oscillations and a small-amplitude 3/2 NTM, and suggests the possibility of a new and easier operational scenario for NTM control.

  1. 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.

  2. 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.

  3. Development of a low-noise 10 K J-T refrigeration system. Technical progress report

    SciTech Connect

    Paugh, R.L.

    1989-09-15

    The purpose of this contract extension is the continuation of the development of a compact, microminiature, low-noise, closed-cycle, Joule-Thomson refrigeration system for 10K operation for use in infrared sensing, low noise microwave signal detection and high speed superconducting electronic data processing. Work is continuing in the following areas: (a) Ongoing refrigerator design and development; (b) Compressor assembly and test, (c) Implementation of gas cleansing techniques, and (d) System integration.

  4. Development of a low-noise 10K J-T refrigeration system. Technical progress report

    SciTech Connect

    Little, W.A.; Edman, H.; Stewart, M.; DuBois, M.; Nasg, A.

    1986-08-15

    This report summarizes the work done to date, in the first 30 days on the development of a low-noise, Joule-Thomson, microminiature refrigeration system designed for 10K operation. The plan of attack for the present contract has three major parts to it: first, the development of the three-stage refrigerator; second, the development of a suitable compressor to provide the gases, and thirdly, the development of an effective gas-cleansing system.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Development of a hermetically sealed brushless DC motor for a J-T cryocooler

    NASA Technical Reports Server (NTRS)

    Joscelyn, Edwin; Hochler, Irwin; Ferri, Andrew; Rott, Heinz; Soukaris, Ted

    1996-01-01

    This development was sponsored by Ball Aerospace for the Cryogenic On-Orbit LongLife Active Refrigerator (COOLLAR) program. The cryocooler is designed to cool objects to 65 K and operate in space for at least 7 years. The system also imports minimal impact to the spacecraft in terms of vibration and heat. The basic Joule-Thompson cycle involves compressing a working fluid, nitrogen in this case, at near-constant temperature from 17.2 KPa to 6.89 MPa. The nitrogen is then expanded through a Joule-Thompson valve. The pure nitrogen gas must be kept clean; therefore, any contamination from motor organic materials must be eliminated. This requirement drove the design towards sealing of the motor within a titanium housing without sacrificing motor performance. It is estimated that an unsealed motor would have contributed 1.65 g of contaminants, due to the organic insulation and potting materials, over the 7-year life. This paper describes the motor electrical and mechanical design, as well as the sealing difficulties encountered, along with their solutions.

  10. Infrared TV measurement of fast ion loss on JT-60U

    NASA Astrophysics Data System (ADS)

    Tobita, K.; Neyatani, Y.; Kusama, Y.; Takeuchi, H.

    1995-01-01

    Toroidal field (TF) ripple transport, wave-particle interaction, and large magnetohydrodynamic modes can enhance fast ion losses and result in localized heat deposition on the first wall. Two-dimensional (2D) thermal measurement on the first wall provides useful information concerning these fast ion behaviors. In this article, we focus on the application of the 2D measurement with an infrared TV camera to TF ripple loss study. The content is (1) the 2D heat flux profile on the wall due to ripple loss, (2) the effects of the radial electric field, and (3) the ICRF effect on TF ripple loss. These experimental data demonstrate a great potential of infrared thermography in fast ion behavior study.

  11. Performance evaluation of heat exchanger for mixed refrigerant J-T cryocooler

    NASA Astrophysics Data System (ADS)

    Ardhapurkar, P. M.; Sridharan, Arunkumar; Atrey, M. D.

    2014-09-01

    In mixed refrigerant Joule-Thomson cryocooler, a multi-component mixture of nitrogen-hydrocarbons undergoes evaporation and condensation process in a helical coiled heat exchanger simultaneously at different pressures. Experimental data and empirical correlations for predicting heat transfer coefficients of evaporating and condensing streams of multi-component mixtures at cryogenic temperatures are unavailable. As a result, design of these heat exchangers is a challenging task. The present work aims to address this challenge. It assesses the existing condensation correlations against the calculated data obtained during experimentation. Experiments are conducted to determine overall heat transfer coefficients along the length of the heat exchanger for various mixtures. The paper studies the applicability of these correlations to the multi-component mixtures at cryogenic temperatures.

  12. Validation of 3D Code KATRIN For Fast Neutron Fluence Calculation of VVER-1000 Reactor Pressure Vessel by Ex-Vessel Measurements and Surveillance Specimens Results

    NASA Astrophysics Data System (ADS)

    Dzhalandinov, A.; Tsofin, V.; Kochkin, V.; Panferov, P.; Timofeev, A.; Reshetnikov, A.; Makhotin, D.; Erak, D.; Voloschenko, A.

    2016-02-01

    Usually the synthesis of two-dimensional and one-dimensional discrete ordinate calculations is used to evaluate neutron fluence on VVER-1000 reactor pressure vessel (RPV) for prognosis of radiation embrittlement. But there are some cases when this approach is not applicable. For example the latest projects of VVER-1000 have upgraded surveillance program. Containers with surveillance specimens are located on the inner surface of RPV with fast neutron flux maximum. Therefore, the synthesis approach is not suitable enough for calculation of local disturbance of neutron field in RPV inner surface behind the surveillance specimens because of their complicated and heterogeneous structure. In some cases the VVER-1000 core loading consists of fuel assemblies with different fuel height and the applicability of synthesis approach is also ambiguous for these fuel cycles. Also, the synthesis approach is not enough correct for the neutron fluence estimation at the RPV area above core top. Because of these reasons only the 3D neutron transport codes seem to be satisfactory for calculation of neutron fluence on the VVER-1000 RPV. The direct 3D calculations are also recommended by modern regulations.

  13. 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.

  14. Off-axis current drive and real-time control of current profile in JT-60U

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Ide, S.; Oikawa, T.; Fujita, T.; Ishikawa, M.; Seki, M.; Matsunaga, G.; Hatae, T.; Naito, O.; Hamamatsu, K.; Sueoka, M.; Hosoyama, H.; Nakazato, M.; JT-60 Team

    2008-04-01

    Aiming at optimization of current profile in high-β plasmas for higher confinement and stability, a real-time control system of the minimum of the safety factor (qmin) using the off-axis current drive has been developed. The off-axis current drive can raise the safety factor in the centre and help to avoid instability that limits the performance of the plasma. The system controls the injection power of lower-hybrid waves, and hence its off-axis driven current in order to control qmin. The real-time control of qmin is demonstrated in a high-β plasma, where qmin follows the temporally changing reference qmin,ref from 1.3 to 1.7. Applying the control to another high-β discharge (βN = 1.7, βp = 1.5) with m/n = 2/1 neo-classical tearing mode (NTM), qmin was raised above 2 and the NTM was suppressed. The stored energy increased by 16% with the NTM suppressed, since the resonant rational surface was eliminated. For the future use for current profile control, current density profile for off-axis neutral beam current drive (NBCD) is for the first time measured, using the motional Stark effect diagnostic. Spatially localized NBCD profile was clearly observed at the normalized minor radius ρ of about 0.6-0.8. The location was also confirmed by multi-chordal neutron emission profile measurement. The total amount of the measured beam driven current was consistent with the theoretical calculation using the ACCOME code. The CD location in the calculation was inward shifted than the measurement.

  15. 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.

  16. 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...

  17. 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...

  18. Relation between the Oxygen Contents in the Neutral Beam and in the Core Plasma in JT-60U

    NASA Astrophysics Data System (ADS)

    Nakano, Tomohide; Koide, Yoshihiko; Honda, Atsushi; Umeda, Naotaka; Akino, Noboru; Higashijima, Satoru; Takenaga, Hidenobu; Kubo, Hirotaka

    The D? spectral lines emitted from the neutral beam colliding with residual D2 in a beam chamber were observed. The Doppler shifts of these D? spectral lines indicate that the neutral beam includes deuterium atoms with energies of E, E/2, E/3 and E/9 E/11 (E : beamaccelerationenergy), which originate from D+, D+2, D+3 and DiO+ (i=1,2,3), respectively. From the intensity ratio of the D? spectral lines, the fraction of oxygen atoms to deuterium atoms was determined by the analysis on atomic and molecular processes in the neutralizer for the neutral beam. The neutral beam has been found to contain more than 8% of oxygen atoms over deuterium when the neutral beam injection starts. About 50% of the oxygen ions in the core plasma originate from the neutral beam. The oxygen content in the neutral beam decreases gradulally with its injection, and it reaches 1% around 850 injections. At this time, the fraction of the oxygen ions in the core plasma originating from the neutral beam is less than 20%. In L-mode plasmas, the confinement time of the oxygen ions originating from the neutral beam is estimated to be 0.5 s, and is longer than that of the deuterium ions ( 0.3 s ).

  19. 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...

  20. 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

    ...-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 inspection... published in the OEM's engine manual. We agree and changed paragraph (t) to state: ``For the purpose of...

  1. 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...

  2. 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

    ... manufacturer's time limits section (TLS) to include enhanced inspection of selected critical life- limited parts at each piece-part opportunity. This AD modifies the TLS of the manufacturer's engine manual and an air carrier's approved continuous airworthiness maintenance program to incorporate...

  3. 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

    .... That AD currently requires revisions to the engine manufacturer's time limits section (TLS) to include... AD would modify the TLS of the manufacturer's engine manual and an air carrier's approved continuous airworthiness maintenance program to incorporate additional inspection requirements and reduce the...

  4. Effects of toroidal rotation shear and magnetic shear on thermal and particle transport in plasmas with electron cyclotron heating on JT-60U

    NASA Astrophysics Data System (ADS)

    Yoshida, M.; Honda, M.; Narita, E.; Hayashi, N.; Urano, H.; Nakata, M.; Miyato, N.; Takenaga, H.; Ide, S.; Kamada, Y.

    2015-07-01

    Increases in thermal and particle transport with electron cyclotron heating (ECH) that are observed in many tokamaks can be a critical issue in establishing ITER operational scenarios with electron heating. To address the issues, conditions with no increase in the thermal and particle transport with ECH have been experimentally investigated in positive magnetic shear, weak magnetic shear (WS) and reversed magnetic shear plasmas with internal transport barrier in the ion channel. The ion heat diffusivity (?i) around the internal transport barrier in the ion temperature remains constant with ECH when a large negative toroidal rotation shear (|dV?/dr| > 4 105 s-1) is formed before the ECH. On the other hand, ?i increases on the condition that the toroidal rotation shear is small or positive. The characteristics do not depend on magnetic shear, the electron to ion temperature ratio (Te/Ti) and ECH power. The electron heat diffusivity stays constant with ECH when the magnetic shear is negative. Effective particle transport remains constant or reduces during ECH under the condition of negative magnetic shear. An observation indicates that there is no threshold of the negative magnetic shear or a very small one for the electron channel sustainment; the electron thermal and particle confinement is maintained during ECH with a small negative magnetic shear in the WS operation.

  5. 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

    ... Register published on April 11, 2000 (65 FR 19477-78). Examining the AD Docket You may examine the AD... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3.... This proposed AD would require overhauling fan blade leading edges at the first shop visit after...

  6. 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; Morn, Constanza; Garrabou, Glria; Valero, Joaqun; 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. PMID:25132006

  7. 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

    ... 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) Will... gearbox removal or gearbox change would fit into the shop visit definition. Also, that we clarify that...

  8. 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.

  9. Incessant Palpitations and Narrow Complex Tachycardia.

    PubMed

    Han, Frederick T

    2016-03-01

    Junctional tachycardia (JT) is rare cause of supraventricular tachycardia. The intracardiac activation sequence is similar to atrioventricular nodal reentrant tachycardia (AVNRT). Premature atrial contractions inserted during tachycardia can help distinguish JT from AVNRT. As noted in this case, slow pathway ablation for JT may not always be effective for termination of JT. Activation mapping during JT identified a low-amplitude potential in the region of the coronary sinus ostium and the inferior margin of the triangle of Koch that marked the successful ablation site for JT. PMID:26920171

  10. Validation of a model for radon-induced background processes in electrostatic spectrometers

    NASA Astrophysics Data System (ADS)

    Wandkowsky, N.; Drexlin, G.; Frnkle, F. M.; Glck, F.; Groh, S.; Mertens, S.

    2013-08-01

    The Karlsruhe Tritium Neutrino (KATRIN) experiment investigating tritium ?-decay close to the endpoint with unprecedented precision has stringent requirements on the background level of less than 10-2 counts per second. Electron emission during the ?-decay of 219, 220Rn atoms in the electrostatic spectrometers of KATRIN is a serious source of background exceeding this limit. In this paper we compare extensive simulations of Rn-induced background to specific measurements with the KATRIN pre-spectrometer to fully characterize the observed Rn-background rates and signatures and determine generic Rn emanation rates from the pre-spectrometer bulk material and its vacuum components.

  11. Le sacrum de Sterkfontein Sts 14 Q ( Australopithecus africanus): nouvelles donnes sur la croissance et sur l'ge osseux du spcimen (hommage R. Broom et J.T. Robinson) . The sacrum of Sterkfontein Sts 14 Q (Australopithecus africanus): new data on the growth and on the osseus age of the specimen (homage to R. Broom and J.T. Robinson)

    NASA Astrophysics Data System (ADS)

    Berge, Christine; Gommery, Dominique

    1999-08-01

    The fossil sacrum of Sterkfontein Sts 14Q ( Australopithecus africanus) was compared with 96 human sacrums of known age so as to reveal its growth stage. Robinson (1972) noticed the presence of an immature trait (unfused intervertebral disc between S1 and S2) in this individual which in other respects is supposed to be a fully matured adult. Our study brings us to define a "sub-adult" category corresponding to a class between the ages of 16 to 25 years in modern humans. Sts 14Q had the same state of maturation, which corresponds to a post-pubertal individual which had not finished its growth concerning the sacral breadth, and probably the pelvic breadth.

  12. 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.

  13. TRITIUM-?-DECAY Experiments - the Direct way to the Absolute Neutrino Mass

    NASA Astrophysics Data System (ADS)

    Bornschein, Lutz

    2013-11-01

    Tritium-?-decay experiments provide the most sensitive approach to measure the absolute neutrino mass in a model independent way. The Karlsruhe Tritium Neutrino experiment KATRIN will measure the neutrino mass scale with an expected sensitivity of 0.2 eV/c2 (90% C.L.) and so will help to clarify the roles of neutrinos in the early universe. KATRIN investigates spectroscopically the electron spectrum from tritium ?-decay 3 H -> 3 {He} + {e}^ - + bar ? e close to the kinematic endpoint of 18.6 keV. It will use a windowless gaseous tritium source in combination with an electrostatic filter for energy analysis. KATRIN is currently under construction at the Karlsruhe Institute of Technology (KIT) Campus North. This proceeding will give an overview of the status of the main components of the KATRIN experiment.

  14. Characterization of multielectron dynamics in molecules: A multiconfiguration time-dependent Hartree-Fock picture

    SciTech Connect

    Ohmura, Shu; Kono, Hirohiko; Oyamada, Takayuki; Kato, Tsuyoshi; Nakai, Katsunori; Koseki, Shiro

    2014-09-21

    Using the framework of multiconfiguration theory, where the wavefunction ?(t) of a many-electron system at time t is expanded as ?(t)=?{sub I}C{sub I}(t)?{sub I}(t) in terms of electron configurations (?{sub I}(t)), we divided the total electronic energy E(t) as E(t)=?{sub I}|C{sub I}(t)|{sup 2}E{sub I}(t) . Here E{sub I}(t) is the instantaneous phase changes of C{sub I}(t) regarded as a configurational energy associated with ?{sub I}(t). We then newly defined two types of time-dependent states: (i) a state at which the rates of population transfer among configurations are all zero; (ii) a state at which (E{sub I}(t)) associated with the quantum phases of C{sub I}(t) are all the same. We call the former time-dependent state a classical stationary state by analogy with the stationary (steady) states of classical reaction rate equations and the latter one a quantum stationary state. The conditions (i) and (ii) are satisfied simultaneously for the conventional stationary state in quantum mechanics. We numerically found for a LiH molecule interacting with a near-infrared (IR) field ?(t) that the condition (i) is satisfied whenever the average velocity of electrons is zero and the condition (ii) is satisfied whenever the average acceleration is zero. We also derived the chemical potentials ?{sub j}(t) for time-dependent natural orbitals ?{sub j}(t) of a many-electron system. The analysis of the electron dynamics of LiH indicated that the temporal change in ??{sub j}(t) ? ?{sub j}(t) + ?(t) d{sub j}(t) ? ?{sub j}(0) correlates with the motion of the dipole moment of ?{sub j}(t), d{sub j}(t). The values ??{sub j}(t) are much larger than the energy ?{sub j}(t) directly supplied to ?{sub j}(t) by the field, suggesting that valence electrons exchange energy with inner shell electrons. For H{sub 2} in an intense near-IR field, the ionization efficiency of ?{sub j}(t) is correlated with ??{sub j}(t). Comparing ??{sub j}(t) to ?{sub j}(t), we found that energy accepting orbitals of ??{sub j}(t) > ?{sub j}(t) indicate high ionization efficiency. The difference between ??{sub j}(t) and ?{sub j}(t) is significantly affected by electron-electron interactions in real time.

  15. 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

  16. Re-reading "The Secret Garden."

    ERIC Educational Resources Information Center

    Gohlke, Madelon S.

    1980-01-01

    Reconstructs the childhood experience of reading "The Secret Garden." Relates the circumstances of that experience to thoughts about transactional criticism, human intellectual development, bibliotherapy, and psychotherapy. (JT)

  17. 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 function of temperature. The critical bond percolation threshold and the critical tunneling parameter are also obtained.

  18. 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.

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

    PubMed

    Jurez-Rodrguez, Mara Dolores; Torres-Escobar, Ascencin; 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 (?qseB) mutant and lsrRK double deletion mutants (?lsrRK). 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. PMID:23353051

  20. 40 CFR 87.1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... which is installed in or which is manufactured for installation in an aircraft. Aircraft gas turbine... T3, T8, and TSS. Class T3 means all aircraft gas turbine engines of the JT3D model family. Class T8 means all aircraft gas turbine engines of the JT8D model family. Class TSS means all aircraft...

  1. 40 CFR 87.1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... which is installed in or which is manufactured for installation in an aircraft. Aircraft gas turbine... T3, T8, and TSS. Class T3 means all aircraft gas turbine engines of the JT3D model family. Class T8 means all aircraft gas turbine engines of the JT8D model family. Class TSS means all aircraft...

  2. 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.

  3. Analysis of two-stage Joule-Thomson expansion

    NASA Astrophysics Data System (ADS)

    Narasaki, Katsuhiro

    2016-03-01

    To cool far infrared detectors for infrared observation or superconductor-insulator-superconductor (SIS) mixers for atmospheric observation, 1 K-class and 4 K-class coolers have been developed. These coolers consist of a two-stage Stirling cooler for pre-cooling and a Joule-Thomson (JT) cooler with a single JT valve. This paper presents descriptions of theoretical analyses based on enthalpy balance to elucidate the benefits of a two-stage JT valve type compared with those of a single JT valve type in a JT cooler. First, relational expressions for heat balance analysis of enthalpy for single-stage JT expansion are introduced. Then similar relational expressions for two-stage JT expansion are introduced under some assumptions. Results of heat balance analyses using several parameters demonstrated that, using two-stage JT expansion, the cooling capacity for a 1 K-class cooler is improved by 100%; that of a 4 K-class cooler is improved by about 30%.

  4. 14 CFR 36.1 - Applicability and definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... certification procedure. Editorial Note: For Federal Register citations affecting § 36.1, see the List of CFR..., except for airplanes that are powered by Pratt & Whitney Turbo Wasp JT3D series engines; (ii) December 31... & Whitney Turbo Wasp JT3D series engines; and (iii) December 31, 1974, for airplanes with maximum weights...

  5. 14 CFR 36.1 - Applicability and definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... certification procedure. Editorial Note: For Federal Register citations affecting § 36.1, see the List of CFR..., except for airplanes that are powered by Pratt & Whitney Turbo Wasp JT3D series engines; (ii) December 31... & Whitney Turbo Wasp JT3D series engines; and (iii) December 31, 1974, for airplanes with maximum weights...

  6. 14 CFR 36.1 - Applicability and definitions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... certification procedure. Editorial Note: For Federal Register citations affecting § 36.1, see the List of CFR..., except for airplanes that are powered by Pratt & Whitney Turbo Wasp JT3D series engines; (ii) December 31... & Whitney Turbo Wasp JT3D series engines; and (iii) December 31, 1974, for airplanes with maximum weights...

  7. 14 CFR 36.1 - Applicability and definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... certification procedure. Editorial Note: For Federal Register citations affecting § 36.1, see the List of CFR..., except for airplanes that are powered by Pratt & Whitney Turbo Wasp JT3D series engines; (ii) December 31... & Whitney Turbo Wasp JT3D series engines; and (iii) December 31, 1974, for airplanes with maximum weights...

  8. A GLIMPSE INTO THE EYE OF THE EMERGENCY RESPONSE AT EPA KATRINA AND RITA

    EPA Science Inventory

    This presentation was given at the Texas Environmental Health Association Annual Meeting in Round Rock, TX on October 12, 2005. The keynote address was focused on the conditions after Katrins, organizing response, field response, EPA's role in emergency response, what is EPA doi...

  9. Environmental contaminants in oil field produced waters discharged into wetlands

    SciTech Connect

    Ramirez, P. Jr.

    1994-12-31

    The 866-acre Loch Katrine wetland complex in Park County, Wyoming provides habitat for many species of aquatic birds. The complex is sustained primarily by oil field produced waters. This study was designed to determine if constituents in oil field produced waters discharged into Custer Lake and to Loch Katrine pose a risk to aquatic birds inhabiting the wetlands. Trace elements, hydrocarbons and radium-226 concentrations were analyzed in water, sediment and biota collected from the complex during 1992. Arsenic, boron, radium-226 and zinc were elevated in some matrices. The presence of radium-226 in aquatic vegetation suggests that this radionuclide is available to aquatic birds. Oil and grease concentrations in water from the produced water discharge exceeded the maximum 10 mg/l permitted by the WDEQ (1990). Total aliphatic and aromatic hydrocarbon concentrations in sediments were highest at the produced water discharge, 6.376 {mu}g/g, followed by Custer Lake, 1.104 {mu}g/g. The higher levels of hydrocarbons found at Custer Lake, compared to Loch Katrine, may be explained by Custer Lake`s closer proximity to the discharge. Benzo(a)pyrene was not detected in bile from gadwalls collected at Loch Katrine but was detected in bile from northern shovelers collected at Custer Lake. Benzo(a)pyrene concentrations in northern shoveler bile ranged from 500 to 960 ng/g (ppb) wet weight. The presence of benzo(a)pyrene in the shovelers indicates exposure to petroleum hydrocarbons.

  10. Anomalous high-pressure Jahn-Teller behavior in CuWO4.

    PubMed

    Ruiz-Fuertes, J; Segura, A; Rodríguez, F; Errandonea, D; Sanz-Ortiz, M N

    2012-04-20

    High-pressure optical-absorption measurements performed in CuWO(4) up to 20 GPa provide experimental evidence of the persistence of the Jahn-Teller (JT) distortion in the whole pressure range both in the low-pressure triclinic and in the high-pressure monoclinic phase. The electron-lattice couplings associated with the e(g)(E⊗e) and t(2g)(T⊗e) orbitals of Cu(2+) in CuWO(4) are obtained from correlations between the JT distortion of the CuO(6) octahedron and the associated structure of Cu(2+) d-electronic levels. This distortion and its associated JT energy (E(JT)) decrease upon compression in both phases. However, both the distortion and associated E(JT) increase sharply at the phase-transition pressure (P(PT)=9.9 GPa), and we estimate that the JT distortion persists for a wide pressure range not being suppressed up to 37 GPa. These results shed light on the transition mechanism of multiferroic CuWO(4), suggesting that the pressure-induced structural phase transition is a way to minimize the distortive effects associated with the toughness of the JT distortion. PMID:22680738

  11. A miniature Joule-Thomson cooler for optical detectors in space.

    PubMed

    Derking, J H; Holland, H J; Tirolien, T; ter Brake, H J M

    2012-04-01

    The utilization of single-stage micromachined Joule-Thomson (JT) coolers for cooling small optical detectors is investigated. A design of a micromachined JT cold stage-detector system is made that focuses on the interface between a JT cold stage and detector, and on the wiring of the detector. Among various techniques, adhesive bonding is selected as most suitable technique for integrating the detector with the JT cold stage. Also, the optimum wiring of the detector is discussed. In this respect, it is important to minimize the heat conduction through the wiring. Therefore, each wire should be optimized in terms of acceptable impedance and thermal heat load. It is shown that, given a certain impedance, the conductive heat load of electrically bad conducting materials is about twice as high as that of electrically good conducting materials. A micromachined JT cold stage is designed and integrated with a dummy detector. The JT cold stage is operated at 100 K with nitrogen as the working fluid and at 140 K with methane. Net cooling powers of 143 mW and 117 mW are measured, respectively. Taking into account a radiative heat load of 40 mW, these measured values make the JT cold stage suitable for cooling a photon detector with a power dissipation up to 50 mW, allowing for another 27 to 53 mW heat load arising from the electrical leads. PMID:22559586

  12. 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.

  13. A miniature Joule-Thomson cooler for optical detectors in space

    NASA Astrophysics Data System (ADS)

    Derking, J. H.; Holland, H. J.; Tirolien, T.; ter Brake, H. J. M.

    2012-04-01

    The utilization of single-stage micromachined Joule-Thomson (JT) coolers for cooling small optical detectors is investigated. A design of a micromachined JT cold stage-detector system is made that focuses on the interface between a JT cold stage and detector, and on the wiring of the detector. Among various techniques, adhesive bonding is selected as most suitable technique for integrating the detector with the JT cold stage. Also, the optimum wiring of the detector is discussed. In this respect, it is important to minimize the heat conduction through the wiring. Therefore, each wire should be optimized in terms of acceptable impedance and thermal heat load. It is shown that, given a certain impedance, the conductive heat load of electrically bad conducting materials is about twice as high as that of electrically good conducting materials. A micromachined JT cold stage is designed and integrated with a dummy detector. The JT cold stage is operated at 100 K with nitrogen as the working fluid and at 140 K with methane. Net cooling powers of 143 mW and 117 mW are measured, respectively. Taking into account a radiative heat load of 40 mW, these measured values make the JT cold stage suitable for cooling a photon detector with a power dissipation up to 50 mW, allowing for another 27 to 53 mW heat load arising from the electrical leads.

  14. 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.

  15. SIDE DETAIL OF LEFT ENGINE MAINTENANCE. FLAPS ARE RESTRAINED WITH ...

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

    SIDE DETAIL OF LEFT ENGINE MAINTENANCE. FLAPS ARE RESTRAINED WITH LOCKS TO FACILITATE LUBRICATION. ENGINE IDENTIFIED AS #709075, PRATT & WHITNEY 200 JT 8 MODEL. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

  16. Female condoms

    MedlinePLUS

    ... female condoms at most drugstores, STI clinics, and family planning clinics. You need to plan to have a ... Jensen JT, Mishell DR. Family planning: contraception, ... Katz VL, eds. Comprehensive Gynecology . 6th ed. Philadelphia, ...

  17. Hey Mister! It's Upside Down!

    ERIC Educational Resources Information Center

    Gilbert, Robert K.

    1977-01-01

    A graphing activity which allows students to work independently of the teacher and the textbook is described. The activity involves providing data in order to develop the skills necessary for interpreting the collected information. (JT)

  18. 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)

  19. Cleidocranial dysostosis

    MedlinePLUS

    Horton WA, Hecht JT. Disorders involving transcription factors. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011: ...

  20. 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)

  1. Bookstores and Profits

    ERIC Educational Resources Information Center

    College Store Journal, 1975

    1975-01-01

    Guidelines by the National Association of College Stores for making academically oriented bookstores financially viable with suggested alternative ways of implementing the guidelines (e.g. retail business, subsidized service, etc.) (JT)

  2. ENVIRONMENTAL IMPACTS AND MONITORING: A HISTORICAL PERSPECTIVE ON THE USE OF NATURAL ATTENUATION FOR SUBSURFACE REMEDIATION: BOOK CHAPTER

    EPA Science Inventory

    BOOK CHAPTER NRMRL-ADA-01128 West, CC, and Wilson*, J.T. "Environmental Impacts and Monitoring: A Historical Perspective on the Use of Natural Attenuation for Subsurface Remediation." In: Environmental Chemistry: Fate, ...

  3. 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.

  4. Jobs with Service Programs: Home Services

    ERIC Educational Resources Information Center

    Kahl, Anne

    1976-01-01

    A review of the kinds of jobs available in services developed to help the homebound elderly: Home health care, homemaker-home health aide, chore service, home repair and maintenance, home-delivered meals, telephone reassurance, and friendly visiting. (JT)

  5. Achondrogenesis

    MedlinePLUS

    Horton WA, Hecht JT. Disorders involving ion transporters. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011: ...

  6. 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)

  7. Jobs With Service Programs: Legal Services

    ERIC Educational Resources Information Center

    Rones, Philip L.

    1976-01-01

    A discussion of how legal services are becoming more responsive to the needs of the elderly with focus on job training and opportunities for lawyers, paralegals, and community service advisors (CSAs). (JT)

  8. Aortic aneurysm repair - endovascular - discharge

    MedlinePLUS

    ... term outcome of open or endovascular repair of abdominal aortic aneurysm. N Engl J Med . 2010 May 20;362( ... 20484396 . Greenhalgh RM, Powell JT. Endovascular repair of abdominal aortic aneurysm. N Engl J Med . 2008 Jan 31;358( ...

  9. 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.

  10. Design for a Training Centre

    ERIC Educational Resources Information Center

    Canadian Training Methods, 1976

    1976-01-01

    Briefly describes the design for Cantrakon (Canadian Training and Conference Centre) being built for $8 million by Mont Ste-Marie Ltd. to provide first-class conference facilities to attract Canadian government and industry and also international conferences. (JT)

  11. 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)

  12. 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)

  13. Emerging Consequences of Financing Private Colleges with Public Money

    ERIC Educational Resources Information Center

    Smith, Michael R.

    1975-01-01

    The question of public aid to private colleges is analyzed in historical perspective and in terms of current trends and future outlook followed by a presentation of applicable federal and state supreme court decisions. (JT)

  14. Gingivostomatitis

    MedlinePLUS

    ... children. It may occur after infection with the herpes simplex virus type 1 (HSV-1), which also causes cold ... Livingstone; 2015:chap 174. Schiffer JT, Corey L. Herpes simplex virus. In: Bennett JE, ed. Mandell, Douglas, and Bennett's ...

  15. 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)

  16. Narrow Complex Tachycardia: What is the Mechanism?

    PubMed

    Refaat, Marwan M; Scheinman, Melvin; Badhwar, Nitish

    2016-03-01

    This article presents a diagnostic dilemma in which atrioventricular nodal reentrant tachycardia (AVNRT) and junctional tachycardia (JT) were differentiated based on tachycardia initiation with atrial extrastimulus as well as on the response to progressive decremental atrial extrastimuli. The progressive increase in A2H2' and H2H2' in response to atrial extrastimuli favors reentry as the mechanism of the tachycardia. This is a novel mechanistic differentiation of AVNRT from focal JT. PMID:26920172

  17. A cryogenic heat exchanger with bypass and throttling and its thermodynamic analysis

    NASA Astrophysics Data System (ADS)

    Tao, X.; Liu, D. L.; Wang, L. Y.; Shen, J.; Gan, Z. H.

    2015-12-01

    A precooled Joule-Thomson (J-T) cooler refrigerates at liquid helium temperature. Its third stage heat exchanger works below 20 K. Hot fluid cannot be sufficiently cooled due to nonidealism of the heat exchanger and helium-4 properties. In a J-T cycle of low pressure ratio, the heat exchanger with bypass and throttling improves the refrigeration capacity. Bypass and throttling reduces the temperature difference and entropy generation within the heat exchanger.

  18. 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.

  19. Joule-Thomson Expander Without Check Valves

    NASA Technical Reports Server (NTRS)

    Chan, C. K.; Gatewood, J. R.

    1989-01-01

    Cooling effected by bidirectional, reciprocating flow of gas. Type of Joule-Thomson (J-T) expander for cryogenic cooling requires no check valves to prevent reverse flow of coolant. More reliable than conventional J-T expander, containing network of check valves, each potential source of failure. Gas flows alternately from left to right and right to left. Heat load cooled by evaporation of liquid from left or right compartment, whichever at lower pressure.

  20. Development of a High Field Superconducting Magnet Cooled by a 2 K Cryocooler (2) Characteristics of 2 K Cryocooler

    NASA Astrophysics Data System (ADS)

    Sato, A.; Nimori, S.; Maeda, M.; Nagai, H.; Matsumoto, F.; Takahashi, M.; Kuriyama, T.; Fujioka, T.; Ito, T.; Okamura, T.

    2004-06-01

    This paper describes the experimental results of a small 2 K Gifford-McMahon/Joule-Thomson type (GM/JT) cryocooler, which was used to cool a high-field superconducting magnet. We improved efficiency of the 2 K cryocooler by using a double Joule-Thomson (JT) valve. We also adopted a high capacity compressor to obtain over 1 W cooling capacity at 1.8 K. To reduce the cooling down time, we adopted a bypass line between the 1st stage heat exchanger and JT valve outlet. The 2 K-GM/JT cryocooler also has 4 K-operation mode, which is used for long time stand-by between 2 K-operation. Every switching between 4 K-mode and 2 K-mode needs many valve operations. To control cooling capacity of GM/JT cryocooler requires difficult manipulation of JT valves. To overcome this shortcoming, we developed an automatically controlling unit, which demonstrated easy operation.

  1. TRAPa cryo-pump for pumping tritium on pre-condensed argon

    NASA Astrophysics Data System (ADS)

    Kazachenko, O.; Bornschein, B.; Bornschein, L.; Eichelhardt, F.; Kernert, N.; Neumann, H.

    2008-03-01

    The TRitium Argon frost Pump experiment (TRAP) has been built at the Tritium Laboratory Karlsruhe (TLK) as a test rig for the Cryogenic Pumping Section (CPS) of the KArlsruhe TRItium Neutrino Experiment (KATRIN). TRAP employs a heterogeneous layer of pre-condensed argon to adsorb hydrogen isotopes at 4.2 K. This article covers the technical setup of the TRAP experiment and presents first results obtained in a commissioning run with deuterium.

  2. 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.

  3. Experimental study of a mixed refrigerant Joule-Thomson cryocooler using a commercial air-conditioning scroll compressor

    NASA Astrophysics Data System (ADS)

    Lee, Jisung; Lee, Kyungsoo; Jeong, Sangkwon

    2013-05-01

    Mixed refrigerant Joule-Thomson (MR J-T) cryocoolers have been used to create cryogenic temperatures and are simple, efficient, cheap, and durable. However, compressors for MR J-T cryocoolers still require optimization. As the MR J-T cryocooler uses a commercial scroll compressor developed for air-conditioning systems, compressor overheating due to the use of less optimized refrigerants may not be negligible, and could cause compressor malfunction due to burn-out of scroll tip seals. Therefore, in the present study, the authors propose procedures to optimize compressor operation to avoid the overheating issue when the MR J-T cryocooler is used with a commercial oil lubricated scroll compressor, and the present experimental results obtained for a MR J-T cryocooler. A single stage 1.49 kW (2 HP) scroll compressor designed for R22 utilizing a mixture of nitrogen and hydrocarbons was used in the present study. As was expected, compressor overheating and irreversible high temperatures at a compressor discharge port were found at the beginning of compressor operation, which is critical, and hence, the authors used a water injection cooling system for the compressor to alleviate temperature overshooting. In addition, a portion of refrigerant in the high-pressure stream was by-passed into the compressor suction port. This allowed an adequate compression ratio, prevented excessive temperature increases at the compressor discharge, and eventually enabled the MR J-T cryocooler to operate stably at 121 K. The study shows that commercial oil lubricated scroll compressors can be used for MR J-T cryocooling systems if care is exercised to avoid compressor overheating.

  4. Helium liquefaction using cryorefrigerators

    NASA Astrophysics Data System (ADS)

    Forth, Hans-Joachim

    1986-12-01

    A two-stage Gifford-McMahon refrigerator with a Joule-Thomson (J-T) stage connected in series, was extended to a small helium liquefier. The plant can operate automatically. Helium is liquefied within the J-T cycle, directly after the J-T valve, into a 3l tank. This liquid He is used for the indirect cooling of an externally accessible sample chamber, either by using helium contact gas, or by means of liquid He condensed from an external helium gas source. The second design is meant for laboratory applications. The liquid helium tank is not incorporated in the J-T cycle, but thermally connected to the J-T stage of the refrigerator. The He gas from an external source is then condensed into the 2l tank. The liquid helium is accessible via a top-loading sample tube. The refrigerating capacity of both devices is 2W at 4.5K. The cleaning procedures for the He gas to be condensed into the tanks, and the production of temperatures below 4.2K in the He bath are described.

  5. Anomalous High-Pressure Jahn-Teller Behavior in CuWO4

    NASA Astrophysics Data System (ADS)

    Ruiz-Fuertes, J.; Segura, A.; Rodríguez, F.; Errandonea, D.; Sanz-Ortiz, M. N.

    2012-04-01

    High-pressure optical-absorption measurements performed in CuWO4 up to 20 GPa provide experimental evidence of the persistence of the Jahn-Teller (JT) distortion in the whole pressure range both in the low-pressure triclinic and in the high-pressure monoclinic phase. The electron-lattice couplings associated with the eg(E⊗e) and t2g(T⊗e) orbitals of Cu2+ in CuWO4 are obtained from correlations between the JT distortion of the CuO6 octahedron and the associated structure of Cu2+ d-electronic levels. This distortion and its associated JT energy (EJT) decrease upon compression in both phases. However, both the distortion and associated EJT increase sharply at the phase-transition pressure (PPT=9.9GPa), and we estimate that the JT distortion persists for a wide pressure range not being suppressed up to 37 GPa. These results shed light on the transition mechanism of multiferroic CuWO4, suggesting that the pressure-induced structural phase transition is a way to minimize the distortive effects associated with the toughness of the JT distortion.

  6. Comparison of particle confinement in the high confinement mode plasmas with the edge localized mode of the Japan Atomic Energy Research Institute Tokamak-60 Upgrade and the DIII-D tokamak

    NASA Astrophysics Data System (ADS)

    Takenaga, H.; Mahdavi, M. A.; Baker, D. R.

    2001-05-01

    Particle confinement was compared for the high confinement mode plasmas with the edge localized mode in the Japan Atomic Energy Research Institute Tokamak-60 Upgrade (JT-60U) [S. Ishida, JT-60 Team, Nucl. Fusion 39, 1211 (1999)] and the DIII-D tokamak [J. L. Luxon et al., Plasma Physics and Controlled Nuclear Fusion Research 1986 (International Atomic Energy Agency, Vienna, 1987), Vol. 1, p. 159] considering separate confinement times for particles supplied by neutral beam injection (NBI) (center fueling) and by recycling and gas-puffing (edge fueling). Similar dependence on the NBI power was obtained in JT-60U and DIII-D. The particle confinement time for center fueling in DIII-D was smaller by a factor of 4 in the low density discharges and by a factor of 1.8 in the high density discharges than JT-60U scaling, respectively, suggesting the stronger dependence on the density in DIII-D. The particle confinement time for edge fueling in DIII-D was comparable with JT-60U scaling in the low density discharges. However, it decreased to a much smaller value in the high density discharges.

  7. Jahn-Teller Transitions in the Bimetallic Oxalates

    SciTech Connect

    Fishman, Randy Scott

    2011-01-01

    Bimetallic oxalates are a class of layered molecule-based magnets with transition-metal ions M(II) and M'(III) coupled by oxalate molecules (C2O4)-2 in an open honeycomb structure. Magnetic compensation (MC) has been observed in ferrimagnetic Fe(II)Fe(III) compounds with certain cations between the bimetallic layers. This behavior can be explained [1] by considering the C3-symmetric crystal field produced by the six oxygen atoms surrounding each Fe ion, which splits the L = 2, 3d6 multiplet on the Fe(II) sites into two doublets and one singlet. MC occurs when the doublet lies lowest in energy and carries an orbital angular momentum Lz between about 0.25 and 1.0. Because the low-energy doublet is half-filled, a Jahn-Teller (JT) distortion may break the C3 symmetry near the ferrimagnetic transition temperature. In the absence of spin-orbit coupling on the Fe(II) sites, the JT distortion would always occur at T = 0. However, due to the competition between the spin-orbit coupling and JT energies, the JT distortion disappears at low temperatures in compounds that display MC [2]. Comparison is made with recent experiments and predictions are made for controlling the MC and JT critical temperatures.

  8. PAPR Reduction of TDD-CDMA Using Joint Transmission Technique

    NASA Astrophysics Data System (ADS)

    Binti Harum, Norharyati; Ohtsuki, Tomoaki; Nakagawa, Masao

    Joint transmission (JT) in time-division-duplex code-division multiple-access (TDD-CDMA) systems can provide a low peak-to-average power ratio (PAPR) for single paths, but causing a high PAPR in multipath environments. To avoid the high PAPR, we propose a new approach to JT technique by selecting certain paths instead of all paths used in JT processing so that PAPR becomes lower. The path selection proposal involves two methods; path selection by taking certain paths from all paths and by taking paths having path gains above a certain threshold value. To enhance the effectiveness of the proposed techniques, we evaluate a combination of the proposed technique with the clipping technique. We evaluate both PAPR and bit error rate (BER) performance for the proposed techniques and its combination with the clipping technique. We compare the results of the proposed techniques with conventional JT technique and the combination techniques with clipping technique. From the results of computer simulation, we show that the proposed path selection techniques perform low PAPR and good BER performance compared to the conventional JT processing. We also show that the combination of proposed path selection technique and clipping performs low PAPR performance without severe BER degradation compared to the conventional clipping technique.

  9. 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.

  10. QT dispersion in amyloidosis due to familial Mediterranean fever.

    PubMed

    Nussinovitch, Udi; Nussinovitch, Naomi; Nussinovitch, Moshe; Volovitz, Benjamin; Feld, Olga; Ben-Zvi, Ilan; Livneh, Avi

    2012-07-01

    Cardiac amyloid deposition in FMF may cause increased QT dispersion (QTd), a marker for cardiac arrhythmias. The aim of this study was to further evaluate repolarization dispersion in familial Mediterranean fever (FMF) with amyloidosis. Findings on 12-lead electrocardiography were compared between 18 patients with FMF-amyloidosis and 18 age- and sex-matched control subjects. Repolarization and dispersion parameters were computed with designated computer software, and results of the 5 beats were subsequently averaged. There were no statistically significant differences between the groups as to average corrected QT interval length, average QTd interval, average QT corrected dispersion, or QT dispersion ratio. JT dispersion and JT corrected dispersion were also similar in both groups. In conclusion, patients with FMF-amyloidosis seem to have QT and JT dispersion parameters similar to those of healthy subjects. Future research and longer follow-ups should be conducted in order to evaluate the prognostic importance of repolarization dispersion parameters in amyloidosis of FMF. PMID:21461715

  11. Coercivity and nanostructure in magnetic spinel Mg(Mn,Fe)2O4

    NASA Astrophysics Data System (ADS)

    Zhang, C. L.; Yeo, S.; Horibe, Y.; Choi, Y. J.; Guha, S.; Croft, M.; Cheong, S.-W.; Mori, S.

    2007-03-01

    When Fe ions in the ferrimagnetic cubic MgFe2O4 are replaced by Jahn-Teller (JT)-active Mn ions, the structure evolves with two-step processes. For example, the quenched cubic MgMn1.5Fe0.5O4 becomes tetragonal and JT distorted with slow cooling. However, with further slow cooling, the clustering tendency of JT-distorted Mn ions induces the formation of a checkerboard nano-self-assembly consisting of Mn-rich (tetragonal, paramagnetic) and -poor (cubic, ferrimagnetic) rods. This morphological evolution accompanies a drastic modification of ferrimagnetic properties, e.g., the magnetic coercivity changes by 25. The nanocheckerboard assembly with ferrimagnetic nanorods with large shape anisotropy can be a platform for ultra high-density memory devices.

  12. Negative ion beam programs at JAERI

    SciTech Connect

    Ohara, Y. )

    1990-08-05

    Three negative ion beam programs for nuclear fusion research are proposed at the Japan Atomic Energy Research Institute (JAERI): a 500 keV, 10 MW deuterium neutral beam injection (NBI) for heating and current drive in the JT-60U tokamak, a 0.5/1 MeV, 50 MW deuterium beam injection for the Fusion Experimental Reactor (FER), and a 2 MeV, 20 mA lithium beam injection for ion temperature measurement in the JT-60U. The 500 keV negative-ion-based NBI system for the JT-60U will be developed in the first step, followed by the development of the reactor relevant 0.5/1 MeV NBI system. This two step development mitigates the risk in developing a MeV class NBI system.

  13. 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.

  14. 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.

  15. NASA ECI programs - Benefits to Pratt and Whitney engines

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1982-01-01

    Proprietary research conducted under the NASA-sponsored Engine Component Improvement program is shown to have advanced the state of such component technologies as thermal barrier coatings, ceramic seal systems, advanced turbine clearance control, and JT9D engine fan design. In addition, the tests conducted have demonstrated the advantages of updated cooling, sealing and aerodynamic designs in the high pressure turbine and compressor of the JT8D engine. These technological advances are being transferred to such novel engine configurations as the PW2037 and NASA Energy Efficient Engine. Attention is given to the results of the thermal coating refinement tests of convectively cooled vanes, and to the development of a single shroud fan design applicable to the JT9D and next-generation engines.

  16. Joule-Thomson cryogenic cooler with extremely high thermal stability

    NASA Technical Reports Server (NTRS)

    Bard, Steven; Wu, J. J.; Trimble, Curt

    1991-01-01

    An 80-K Joule-Thomson (J-T) cooling system designed for the Probe Infrared Laser Spectrometer (PIRLS) proposed for the Huygens Titan Probe of the Cassini Saturn orbiter mission is presented. The cryogenic cooling requirements of the PIRLS instrument are listed, and the cooler system design including details of a J-T cryostat, cold head, and dewar design is described along with the results of a thermal modeling effort and lab cooler performance testing. It is shown that by using active feedback temperature control of the cold head in combination with the self-regulating action of the J-T cryostat, a temperature stability of less than 0.1 mK/min is achieved by the cooler weighting 1.8 kg.

  17. 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.

  18. Performance Investigations of a 4 to 10 K Long-Life Mechanical Cryocooler

    NASA Astrophysics Data System (ADS)

    Gully, W. J.; Glaister, D.; Marquardt, E.

    2004-06-01

    We believe that the quickest way of obtaining a reliable space cooler in the range of 4 to 10 K is to combine a Stirling mechanical cooler with a Joule-Thomson (J-T) cooler. In this approach we perform the bulk of the cooling with the Stirling cooler and use the J-T cooler for the small amount of cooling required at the lowest temperatures. The recuperative J-T stage can reach low temperatures more easily because it does not have the regenerator limitations shared by Stirling and Pulse Tube mechanical coolers. We present our system concept in detail and discuss its merits. To demonstrate the capabilities of a hybrid cooler, we built a breadboard version consisting of a precooler, a J-T circulating compressor, and a cold head. With it we achieved closed-cycle refrigeration rates of 35 mW at 6 K and 10 mW at 3.7 K. For simplicity we used a commercial Gifford McMahon (GM) refrigerator as our precooler and focused on building the J-T compressor and passive cold head. The J-T compressor was an Oxford-style linear compressor equipped with an external reed valve package. The cold head consisted of heat exchangers, heat sinks, and an expansion valve. The system worked quite well. The performance was transparent and the results agreed with our analytical models. We are proceeding with the construction of a full engineering model on a NASA technology development program, the Advanced Cryocooler Development Program (ACTDP). Within 2 years we will have a complete engineering model of the mechanical cryocooler capable of 4 K operation.

  19. 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.

  20. 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.

  1. Improved components for engine fuel savings

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    The Engine Component Improvement (ECI) Project formulated to address near term improvements for current engines is described with emphasis on the development of component technologies to reduce the fuel consumption of CF6, JT9D, and JT8D engines. The technical and economical acceptability and the fuel saving potential of nine concepts are demonstrated. Descriptions of these concepts, results of testing, and the status as to entering airline service are presented. Also presented is the status of the remaining concepts still under development.

  2. An investigation into the mechanics of Joule-Thomson valve plug formation

    NASA Astrophysics Data System (ADS)

    Wade, L.; Donnelly, C.; Joham, E.; Johnson, K.; Phillips, R.

    Plug formation via contaminant condensation in sonic-flow Joule-Thomson (J-T) orifices was experimentally investigated. The cold end of the experimental apparatus consists of a precooler, a counterflow heat exchanger, and the J-T expander. Nitrogen gas is used as the refrigerant and water vapor is used as the contaminant. Results show that for the straight sonic orifices employed, plug formation occurred only in the orifice itself. No contamination condensation was noted on the orifice faces. Mechanisms to describe the observed plug nucleation and growth are proposed.

  3. Structure--properties relationships for manganese perovskites

    SciTech Connect

    Dabrowski, B.; Xiong, X.; Chmaissem, O.; Bukowski, Z.; Jorgensen, J. D.

    1999-10-14

    By combining the results of dc magnetization, ac susceptibility, magnetoresistivity, magnetostriction, and x-ray and neutron powder diffraction data for stoichiometric La{sub 1{minus}x}Sr{sub x}MnO{sub 3} the authors have constructed a phase diagram that describes the magnetic, transport, and structural properties and the relationships among them as a function of composition and temperature. Correlations among physical and structural properties have been observed that are consistent with a competition between ferromagnetism and JT distortion. A metallic state occurs below the Curie temperature when both coherent and incoherent JT distortions are suppressed.

  4. 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.

  5. 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.

  6. Spring-Loaded Joule-Thomson Valve

    NASA Technical Reports Server (NTRS)

    Jones, J. A.; Britcliffe, M. J.

    1986-01-01

    Improved design reduces clogging and maintains constant pressure drop as flow rate varies. Spring-Loaded Joule-Thomson Valve pressure drop regulated by spring pushing stainless-steel ball against soft brass seat. Pressure drop remains nearly constant, regardless of helium flow rate and of any gas contaminants frozen on valve seat. Because springloaded J-T valve maintains constant pressure drop, upstream roomtemperature throttle valve adjusts flow rate precisely for any given upstream pressure. In addition, new valve relatively invulnerable to frozen gas contaminants, which clog fixed-orifice J-T valves.

  7. Power Conversion and Energy Storage System for a Fusion Reactor 3. Performance of Large Electric Power Equipment and Future View 3.5 Latest Technical Trend of Lower Loss Electric Power Conversion Equipment

    NASA Astrophysics Data System (ADS)

    Sato, Yoshihisa

    This paper introduces the loss reduction technology for power supply. Design and manufacture of the power supply for JT-60 was carried out using the high-power thyristor. Although the power supply for JT-60 was high-voltage and large-current, the power supply for ITER or a future nuclear fusion reactor system will be a low-voltage large-current type. It is very important to study the latest technical trend in low loss electric power conversion equipment using turn-off type power devices.

  8. Consumer Perceptions of Health Care Services: Implications for Academic Medicine

    ERIC Educational Resources Information Center

    Ware, John E., Jr.; And Others

    1975-01-01

    Factor analytic development of various measures of consumer perceptions regarding characteristics of doctors and health care services is described. Findings are discussed in relation to program planning and evaluation in medical education, and suggestions for future research are noted. (Editor/JT)

  9. A Substitute for the Strike

    ERIC Educational Resources Information Center

    Bleicher, Michael N.

    1975-01-01

    Presents a wage-withholding proposal for impasse resolution in faculty collective bargaining in a state system. A percentage of each faculty member's salary and a significant contribution from the state treasury are put into an escrow account which goes into the federal treasury if settlement is not reached within 45 days. (JT)

  10. Notes on the Role of Criticism in Educating Future Architects

    ERIC Educational Resources Information Center

    Lifchez, Raymond

    1976-01-01

    Contends that criticism, though it functions in the student-critic dyad as an important mode of learning, does not address vital issues of socialization and creativity confronted in collective work. Without group experience students are misled as to the functioning of the design professional within the work-client setting. (JT)

  11. 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.

  12. Applicability of the Joule-Thomson Cryocooler Coupled with Membrane-Based Purification System for Liquefaction of Natural Gas in Small Quantities

    NASA Astrophysics Data System (ADS)

    Piotrowska, A.; Chorowski, M.

    2008-03-01

    Joule-Thomson (J-T) cryocoolers using gas mixture have been studied theoretically and experimentally for a variety of applications. Gas separation technology using polymer membrane is emerging. In this paper the concept of coupling the J-T cooler with a hollow fiber membranes is presented. The apparatus can be used in many applications, like compressed natural gas (CNG) purification and condensation into LNG or separation and liquefaction of nitrogen from air. The paper describes the system and experimental dependence of the separated nitrogen purity on the membrane inlet air pressure. The Second Law of Thermodynamics is used to optimize the composition of the mixture for natural gas cooling and liquefaction. Possible applications of the system depend on membrane material. Membranes used in separation of N2/air or CO2/CH4 are now commercially available [2,6]. The combination of the J-T cooler with N2/air membrane enables the construction of the liquid nitrogen production system aimed at cryosurgical applications. Similarly, J-T cooler coupled with CO2/CH4 membrane can be used for purification and liquefaction of natural gas in small quantities e.g. satisfying future car refueling system needs.

  13. Programmed Student Achievement: A Hawthorne Effect?

    ERIC Educational Resources Information Center

    Haddad, Nabil F.; And Others

    1975-01-01

    Three groups of college students were given instructions using different testing techniques to determine whether the superior performance obtained with Programed Student Achievement (PA) was due to a Hawthorne Effect. Results seem to preclude any attempt to interpret the effectiveness of PA on that basis. (Editor/JT)

  14. A Professional Supply and Demand Analysis

    ERIC Educational Resources Information Center

    McLaughlin, Gerald W.

    1975-01-01

    A model procedure for supply-and-demand forecasting is presented that can be adapted to many disciplines and can aid in avoiding an under- or over-supply of professionals. The model is illustrated with an examination of the supply and demand of veterinarians in the Southern Regional Education Board area. (Editor/JT)

  15. 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)

  16. Continuing Education for Women, 1960-75: A Critical Appraisal

    ERIC Educational Resources Information Center

    Rice, Joy K.

    1975-01-01

    Examines assumptions and issues underlying the development of continuing education programs for women. Assesses patterns of discontinuous vs. continuous education, accommodation to social norms vs. change, separatist vs. nonseparatist education, and remedial vs. a preventive approach to role definition and lifetime planning. (Editor/JT)

  17. Part-Time Legal Education: The Kelso Report and More

    ERIC Educational Resources Information Center

    Cox, Michael P.

    1976-01-01

    Observing that historically the American legal teaching profession has strongly objected to part-time legal education, the author traces those attitudes through the ninteenth century to the changes in the 1970s, listing factors contributing to full-time legal education's no longer needing to feel threatened by its part-time sibling. (JT)

  18. DTP | Toxicology and Pharmacology Branch (TPB)

    Cancer.gov

    Liao, J.T., T.N. Merriman, E.M. Daniel, M.A. Stedham, A.C. Smith and J.E. Tomaszewski, 1991. The Effect of Intravenous Buthionine Sulfoximine (NSC-326231) on Carboplatin (NSC-241240) Induced Toxicity in Mice.

  19. DeFunis Symposium: DeFunis, An Introduction

    ERIC Educational Resources Information Center

    Henkin, Louis

    1975-01-01

    This introduction to a series of five articles in this issue (vol. 75, no. 3) points up the need for "applied" as well as theoretical consideration of the implications of the DeFunis v. Odegaard case. Discusses policy which legislators, in regulating legal education, may pursue consistently with equal protection. (JT)

  20. 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)

  1. 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)

  2. 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)

  3. FIELD MEASUREMENT OF DISSOLVED OXYGEN: A COMPARISON OF METHODS: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-ADA- 00160 Wilkin*, R.T., McNeil*, M.S., Adair*, C.J., and Wilson*, J.T. Field Measurement of Dissolved Oxygen: A Comparison of Methods. Ground Water Monitoring and Remediation (Fall):124-132 (2001). EPA/600/J-01/403. The abili...

  4. Graduate and Professional Education: An Incisive Look at Dentistry

    ERIC Educational Resources Information Center

    Nyre, Glenn F.; Zhonga, Frida A.

    1975-01-01

    Factors influencing the graduate and professional education of women are reviewed and a successful University of California, Los Angeles (UCLA) School of Dentistry outreach program is described for recruiting women dental students through use of a slide-tape, special publications, and the involvement of school counselors. (JT)

  5. 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

  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 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

  9. 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

  10. 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)

  11. A Study of the Geographical Distribution of Undergraduate Students for the Academic Year 1974-1975

    ERIC Educational Resources Information Center

    Schlegel, John F.; And Others

    1975-01-01

    Statistical tables are presented on geographical distribution of undergraduate pharmacy students (U.S., Canadian, and foreign) in U.S. schools. Number of students are listed for each school of pharmacy (resident, non-resident, foreign), for each state of original residence (attending in-state and out-of-state), and for each foreign country. (JT)

  12. Report of Degrees Conferred by Schools and Colleges of Pharmacy for the Academic Year 1974-1975

    ERIC Educational Resources Information Center

    Rodowskas, Christopher A., Jr.

    1975-01-01

    Statistical tables from the American Association of Colleges of Pharmacy annual survey are presented with some summary commentary. Includes number of male and of female recipients of each degree (BS, BPharm, PharmD, MS, PhD) for each U.S. school. Breakdown by geographical area and by race (by school and by degree) are also presented. (JT)

  13. Graduate Education for Primary Care: Problems and Issues

    ERIC Educational Resources Information Center

    Alpert, Joel J.

    1975-01-01

    Noting the problem of a gap between residency training and primary care practice, the author considers five issues faced by primary care graduate education (the setting, the patients, the curriculum, the students, and the faculty) and the three disciplines involved: internal medicine, pediatrics, and family medicine. (JT)

  14. 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)

  15. 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.

  16. The Place of Colleague Evaluation in the Appraisal of College Teaching: A Review of the Literature

    ERIC Educational Resources Information Center

    Batista, Enrique E.

    1976-01-01

    Little agreement as to criteria for evaluating college teaching was found in a literature review. A list of 10 activities and faculty behaviors that can be more reliably and validly evaluated by fellow colleagues than by students or administrators is presented. Recommendations for upgrading colleague evaluation of teaching are made. (JT)

  17. 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.

  18. 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)

  19. Chiang Mai and Illinois: A Cooperative International Project, 1962-70

    ERIC Educational Resources Information Center

    Doege, Theodore C.; And Others

    1976-01-01

    A relationship between the medical schools of Chiang Mai University and the University of Illinois, part of a national involvement in Thailand's socioeconomic development, is analyzed. Antecedents, activities, outcomes, and problems are reviewed with emphasis on need for sound training, energy, adaptability, and investment of years. (JT)

  20. Adelphi on Wheels

    ERIC Educational Resources Information Center

    Levy, Lawrence C.

    1976-01-01

    Adelphi University has awarded 76 Masters in Business Administration degrees to people in the New York City area who attended its Classroom on Wheels, one specially equipped car on each of four commuter train lines. The program, reaching over 1000 people since 1971 is run and promoted solely on tuition. (JT)

  1. The Corporate Law Curriculum

    ERIC Educational Resources Information Center

    Mofsky, James S.

    1976-01-01

    On the premise that corporate counsel must be an able diagnostician before he can focus on highly specialized and interrelated issues of business law, the author suggests an approach to corporate law curriculum in which the basic course balances the quality and quantity of material designed to create the needed sensitivity. (JT)

  2. 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.

  3. NATURAL BIODEGRADATION OF NTBE ON A SITE ON LONG ISLAND, NY: SYMPOSIUM

    EPA Science Inventory

    NRMRL-ADA-00170 Kolhatkar, R., Wilson*, J.T., and Hinshalwood, G. "Natural Biodegradation of NTBE on a Site on Long Island, NY." In: 6th Intl. In-Situ and On-Site Symposium on Bioremediation of MTBE, Alcohols, and Ethers, Battelle, The Si...

  4. 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)

  5. 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.

  6. 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.

  7. Student Suspension and Expulsion Proceedings in Tax Supported Institutions: What Process is Due?

    ERIC Educational Resources Information Center

    Steinberg, Marc I.

    1975-01-01

    Examines the different procedural safeguards which students enjoy in connection with the various disciplinary measures imposed by public school officials: procedural due process rights of students when they are subject to suspensions of up to 10 days, 10 days to three months, more than three months, and expulsions. (JT)

  8. Personal Liability of Trustees of Educational Institutions

    ERIC Educational Resources Information Center

    Porth, William C.

    1974-01-01

    Examines trustee liability in light of the Stern v. Sibley Memorial Hospital decision which contains "a thorough and well considered exposition on the liability of trustees of charitable corporations as well as useful guidelines to be followed, particularly in the area of conflicts of interests." (JT)

  9. Teaching of Formal Courses by Medical Librarians

    ERIC Educational Resources Information Center

    Martin, Jess A.; And Others

    1975-01-01

    Four courses on the use of the library are described which were taught by librarians at the University of Tennessee Center for Health Services to graduate students in basic medical sciences, dentistry, and pharmacy and undergraduates in medical records administration. Also included is a survey of medical libraries offering such courses. (JT)

  10. 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.

  11. HOW TO PROVIDE AUTOMATIC FIRE PROTECTION FOR YOUR BUILDING.

    ERIC Educational Resources Information Center

    Honeywell, Inc., Minneapolis, Minn.

    THE ADVANTAGES OF PROMPT FIRE DETECTION IS DISCUSSED WITH RESPECT TO THE NATURE AND COST OF FIRES. EQUIPMENT IS DESCRIBED, AND DIAGRAMS OF INSTALLATIONS OF DETECTION AND ALARM SYSTEMS ARE GIVEN FOR SCHOOLS, HOSPITALS, COMMERICAL BUILDINGS, INDUSTRIAL PLANTS, AND CAMPUSES. (JT)

  12. MPI Enhancements in John the Ripper

    NASA Astrophysics Data System (ADS)

    Sykes, Edward R.; Lin, Michael; Skoczen, Wesley

    2010-11-01

    John the Ripper (JtR) is an open source software package commonly used by system administrators to enforce password policy. JtR is designed to attack (i.e., crack) passwords encrypted in a wide variety of commonly used formats. While parallel implementations of JtR exist, there are several limitations to them. This research reports on two distinct algorithms that enhance this password cracking tool using the Message Passing Interface. The first algorithm is a novel approach that uses numerous processors to crack one password by using an innovative approach to workload distribution. In this algorithm the candidate password is distributed to all participating processors and the word list is divided based on probability so that each processor has the same likelihood of cracking the password while eliminating overlapping operations. The second algorithm developed in this research involves dividing the passwords within a password file equally amongst available processors while ensuring load-balanced and fault-tolerant behavior. This paper describes John the Ripper, the design of these two algorithms and preliminary results. Given the same amount of time, the original JtR can crack 29 passwords, whereas our algorithms 1 and 2 can crack an additional 35 and 45 passwords respectively.

  13. 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)

  14. The Effects of Inflation/Recession on Higher Education

    ERIC Educational Resources Information Center

    Bowen, William G.

    1975-01-01

    While costs are increasing and revenues from endowment earnings and gifts decreasing, private and public institutions are being forced to cut spending. The author outlines a national program of competitive fellowship awards designed to help meet these problems and to sustain the quality of higher education. (Editor/JT)

  15. School Learning and Adjustment: Interdisciplinary Training for Pediatricians

    ERIC Educational Resources Information Center

    Rockowitz, Ruth J.; Stebbins, Winifred

    1975-01-01

    Describes and evaluates the School Health Programs of the University of Rochester School of Medicine and Dentistry's pediatric training: first-year lectures, second-year electives, clinical consultation for house officers, and a year-long experience as a local school consulting pediatrician for associate residents and fellows. (JT)

  16. Tort Law: Psychotherapist-Patient Privilege--Patient's Dangerous Condition--Confidentiality--Legal Duty to Warn Potential Victim

    ERIC Educational Resources Information Center

    Burns, Robert E.

    1975-01-01

    After telling a psychologist his intentions to kill Tatiana Tarasoff, Prosenjit Poddar did so. In Tarasoff v. Regents of University of California the psychologist was found liable for not warning the victim of danger. The author contends that the decision, in terms of medical capabilities, may be ahead of its time. (JT)

  17. College Stores 1975--A Challenge to the Publishers

    ERIC Educational Resources Information Center

    Davis, Howard W.

    1976-01-01

    A presentation by the general manager of the Harvard Cooperative Society to the College Division of the Association of American Publishers in which he illustrates with survey data the contention that suggested publishers prices for textbooks are arbitrarily set too low by publishers to cover minimal costs of marketing textbooks. (JT)

  18. An Approach to Assessing Pharmacy Student Competency Development

    ERIC Educational Resources Information Center

    Popovich, Nicholas G.; Martin, F. Gene

    1975-01-01

    Research demonstrated that competency development of senior pharmacy students could be quantified by a series of examinations, which showed that in the last professional year student performance and ability with pharmacy information and knowledge approached and eventually equalled that of registered pharmacists. (JT)

  19. 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)

  20. Evaluation of an Audio Cassette Tape Lecture Course

    ERIC Educational Resources Information Center

    Blank, Jerome W.

    1975-01-01

    An audio-cassette continuing education course (Selected Topics in Pharmacology) from Extension Services in Pharmacy at the University of Wisconsin was offered to a selected test market of pharmacists and evaluated using a pre-, post-test design. Results showed significant increase in cognitive knowledge and strong approval of students. (JT)

  1. INHIBITION OF AROMATASE CYTOCHROME P-450 (ESTROGEN SYNTHETASE) BY DERIVATIVES OF ALPHA-NAPHTHOFLAVONE

    EPA Science Inventory

    alpha-Naphthoflavone (ANF; 7,8-benzoflavone) is a potent competitive inhibitor of human aromatase cytochrome P-450 (J.T. Kellis, Jr. and L.E. Vickery, Science 225, 1032 (1984)). The authors have further investigated inhibition of aromatase by several derivatives of ANF. Using hum...

  2. Interaction of Sex and Year of Enrollment in Student Perceptions of the University Climate

    ERIC Educational Resources Information Center

    Pascarella, Ernest T.

    1976-01-01

    Freshmen at two institutions sampled had significantly higher ratings of the climate on an intellectualism/scholarship factor than seniors. As length of exposure to the institution increased (comparing freshmen with seniors) assessments of the environmental press by male and female students tended to diverge. (Editor/JT)

  3. Parabolic temporal profiles of non-spanning avalanches and their importance for ferroic switching

    NASA Astrophysics Data System (ADS)

    He, X.; Ding, X.; Sun, J.; Salje, E. K. H.

    2016-02-01

    Computer simulation of a ferroelastic switching process shows avalanche formation with universal averaged temporal avalanche profiles ⟨J(t)⟩, where J(t) is the avalanche "amplitude" at time t. The profiles are derived for the three most commonly used "jerk"-singularities, namely, the total change of the potential energy U via J(t) = (dU(t)/dt)2, the energy drop J(t) = -dU/dt, and the stress drop J(t) = -dτxy/dt. The avalanches follow, within the time resolution of our modeling, a universal profile J(t)/Jmax = 1 - 4(t/tmax - 0.5)2 in the a-thermal regime and the thermal regime. Broadening of the profiles towards a 4th order parabola arises from peak overlap or peak splitting. All profiles are symmetric around t/tmax = 0.5 and are expected to hold for switching processes in ferroic materials when the correlations during the avalanche are elastic in origin. High frequency applications of ferroic switching are constrained by this avalanche noise and its characteristic temporal distribution function will determine the bandwidth of any stored or transmitted signal.

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

    PubMed Central

    Brjesson, Stefan; Grnlund-Andersson, Ulrika; Tellgren-Roth, Christian; Melhus, sa

    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-IIIII. 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

  5. Student Pre- and Post-Evaluation of an Off-Campus Clinical Clerkship

    ERIC Educational Resources Information Center

    Campbell, R. Keith

    1975-01-01

    Describes the development and use of standardized forms found to be effective for evaluating clinical clerkship experiences of pharmacy students. Copies of the Preliminary Questionnaire and the Post-Evaluation Form are included along with the goals of the Washington State University College of Pharmacy Clinical Pharmacy Program. (JT)

  6. 77 FR 16916 - Airworthiness Directives; Pratt & Whitney (PW)Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ...)Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for PW JT9D-7R4G2 and -7R4H1 turbofan engines. This AD was... Regulatory Flexibility Act. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation...

  7. 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)

  8. 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)

  9. A Formal Procedure for the Determination of Internship Preferences

    ERIC Educational Resources Information Center

    Grochow, Louise B.; Grochow, Jerrold

    1976-01-01

    The authors describe one way of organizing and formalizing judgements and values so that the senior medical student can prepare a preference list of internship programs that will provide maximum satisfaction to the student when the computer matching program is employed. (JT)

  10. The Teaching of Child Psychiatry in U.S. Medical Schools: Results of a Survey

    ERIC Educational Resources Information Center

    Kivowitz, Julian; Kahn, Virginia

    1976-01-01

    A National survey of 113 medical schools revealed that most have special programs in child psychiatry distinct from adult psychiatry. Content involves clinical evaluation of children, information on child development and psychopathology, assigned reading, and liaison with pediatrics. Most schools have full-time psychiatrists on the faculty. (JT)

  11. 77 FR 46430 - Combined Notice of Filings #1

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... Energy Regulatory Commission Combined Notice of Filings 1 Take notice that the Commission received the... effective 9/1/2011. Filed Date: 7/25/12. Accession Number: 20120725-5038. Comments Due: 5 p.m. ET 8/15/12... filing per 35.13(a)(2)(iii) GMP and CVPSC Jt. Trans. Rate and Compliance Filing (EC11-117) to...

  12. 14 CFR 34.1 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... airplane as defined in 14 CFR part 1 for which a U.S. standard airworthiness certificate or equivalent... in, or which is manufactured for installation in, an aircraft. Aircraft gas turbine engine means a.... Class T3 means all aircraft gas turbine engines of the JT3D model family. Class T8 means all...

  13. 14 CFR 34.1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... airplane as defined in 14 CFR part 1 for which a U.S. standard airworthiness certificate or equivalent... in, or which is manufactured for installation in, an aircraft. Aircraft gas turbine engine means a.... Class T3 means all aircraft gas turbine engines of the JT3D model family. Class T8 means all...

  14. 14 CFR 34.1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... airplane as defined in 14 CFR part 1 for which a U.S. standard airworthiness certificate or equivalent... in, or which is manufactured for installation in, an aircraft. Aircraft gas turbine engine means a.... Class T3 means all aircraft gas turbine engines of the JT3D model family. Class T8 means all...

  15. 40 CFR 87.1 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... involved may be delegated. Aircraft has the meaning given in 14 CFR 1.1, which defines aircraft to mean a... which is manufactured for installation in an aircraft. Aircraft gas turbine engine means a turboprop... T3, T8, and TSS. Class T3 means all aircraft gas turbine engines of the JT3D model family. Class...

  16. 40 CFR 87.1 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... involved may be delegated. Aircraft has the meaning given in 14 CFR 1.1, which defines aircraft to mean a... which is manufactured for installation in an aircraft. Aircraft gas turbine engine means a turboprop... T3, T8, and TSS. Class T3 means all aircraft gas turbine engines of the JT3D model family. Class...

  17. 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.

  18. 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)

  19. 75 FR 39046 - Notice of Determinations Regarding Eligibility To Apply for Worker Adjustment Assistance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    .... Subject firm Location Impact date 73,393 Hewlett-Packard Company, Marlboro, MA......... Division of... America Team. 73,766 JT Sports, LLC Neosho, MO 74,024 Hewlett-Packard Company, Omaha, NE Division of... following certifications have been issued. The date following the company name and location of...

  20. 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)

  1. Methods of Teaching: Ways of Turning Non-Learners into Learners

    ERIC Educational Resources Information Center

    Filella, J.

    1975-01-01

    Nine teaching methods are described (conditioning, habit formation, lecture, audio-visual aids, seminar, case study, simulation games, conscientization, and affective learning) and each discussed with reference to the types of material, learners, and teachers to which it is best suited. (JT)

  2. Illiberal Education

    ERIC Educational Resources Information Center

    Knight, Gary A.; Schotten, Peter

    1975-01-01

    Argues that higher education has become cut off from its intellectual moorings, holding that the vision of universal excellence and equal access has become a reality of universal access and equal excellence, and calling for an examination and evaluation of innovations and reforms proposed by the Newman and Carnegie reports. (JT)

  3. 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)

  4. The Fallacies of Numerical Goals

    ERIC Educational Resources Information Center

    Lester, Richard A.

    1976-01-01

    Discusses the problems inherent in the federal government's statistical method of determining and enforcing goals for the hiring and composition of faculty of colleges and universities with federal contracts. Stress is on the need for revision of the program to correct flaws and eliminate red tape. (Editor/JT)

  5. A mixed-gas miniature Joule-Thomson cooling system

    NASA Astrophysics Data System (ADS)

    Derking, J. H.; Vermeer, C. H.; Tirolien, T.; Crook, M. R.; ter Brake, H. J. M.

    2013-10-01

    A mixed-gas Joule-Thomson (JT) cooling system is investigated in which a micromachined JT cold stage of 60 10 0.7 mm3 is combined with a linear compressor. The cooling system is operated between 1.3 bar and 9.4 bar with a ternary gas mixture of 39 mol% methane, 20 mol% ethane and 41 mol% isobutane. It cools down to below 130 K, and at a cold-tip temperature of 150 K, a cooling power of 46 mW is obtained at a mass-flow rate of 1.35 mg s-1. The background losses are experimentally determined to be 20 mW and are in good agreement with the calculated value of 21 mW. The linear compressor can be used to drive 19 of these miniature JT cold stages in parallel, e.g. for cooling optical detectors in future space missions. In this mode, the compressor pressure ratio is slightly less, resulting in a net cooling power of 23 mW per miniature JT cold stage.

  6. Impurity control and heat removal from core plasma

    SciTech Connect

    Fujisawa, N.; Hamada, Y.; Shimomura, Y.

    1983-12-01

    Jaeri and the Institute of Plasma Physics review the issues of heat and particle removal from core-plasma and related impurity control issues. The representative concepts of impurity-control systems for the DIVA/JET-2a, Doublet-III, JT-60, R-Tokamak, and Fusion Experimental Reactor (FER) tokamaks are described.

  7. Interprofessional Legal Practitioners: The Case of the M.D.-LL.B.

    ERIC Educational Resources Information Center

    Schneller, Eugene Stewart

    1975-01-01

    Careers and problems encountered by the large majority of M.D.-LL.B's who practice legal medicine are examined. The author argues that the legal profession must strive to create institutionalized career lines so that interprofessional medical-legal practice is a well-founded career choice. (JT)

  8. 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)

  9. Death of a College

    ERIC Educational Resources Information Center

    Wood, Herbert H.

    1975-01-01

    Contending that when a college fails it is the governing board that holds final responsibility, the author points out the early warning signals and most frequent mistakes and lists eight rules for survival. Emphasis is on the need to consider more seriously the long-range consequences of decisions. (JT)

  10. Some Effects of Ph.D. Training on the Academic Labour Markets of Australian and British Universities

    ERIC Educational Resources Information Center

    Davis, Denis J.

    1976-01-01

    The background of Ph.D.s is tabulated to show the loss to the stock of university manpower of non-academic but educationally valuable experience through growing competition for jobs by Ph.D.s. The conclusion is that forces causing the Ph.D. displacement of labour in the university academic labour market should be constrained. (Editor/JT)

  11. Junctional Tourniquet Training Experience.

    PubMed

    Kragh, John F; Geracci, James J; Parsons, Donald L; Robinson, John B; Biever, Kimberlie A; Rein, Erling B; Glassberg, Elon; Strandenes, Geir; Chen, Jacob; Benov, Avi; Marcozzi, David; Shackelford, Stacy; Cox, Kevin M; Mann-Salinas, Elizabeth A

    2015-01-01

    Since 2009, out-of-hospital care of junctional hemorrhage bleeding from the trunk-appendage junctions has changed, in part, due to the newly available junctional tourniquets (JTs) that have been cleared by the US Food and Drug Administration. Given four new models of JT available in 2014, several military services have begun to acquire, train, or even use such JTs in care. The ability of users to be trained in JT use has been observed by multiple instructors. The experience of such instructors has been broad as a group, but their experience as individuals has been neither long nor deep. A gathering into one source of the collective experience of trainers of JT users could permit a collation of useful information to include lessons learned, tips in skill performance, identification of pitfalls of use to avoid, and strategies to optimize user learning. The purpose of the present review is to record the experiences of several medical personnel in their JT training of users to provide a guide for future trainers. PMID:26360350

  12. 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)

  13. Pay Policies for Student Workers

    ERIC Educational Resources Information Center

    Counts, Perry

    1975-01-01

    A survey of all types of colleges in nine southern states revealed that 37 percent pay the minimum wage to all student workers and 63 percent pay differential rates. Survey results are reported and a plan for differentiated pay rates based on job classification, seniority, and merit is outlined. (JT)

  14. Medical Treatment and Human Experimentation: Introducing Illegality, Fraud, Duress and Incapacity to the Doctrine of Informed Consent

    ERIC Educational Resources Information Center

    Foster, Constance B.

    1975-01-01

    The court held in Kaimowitz v. Department of Mental Health that "involuntarily detained mental patients cannot give informed and adequate consent to experimental psychosurgical procedures on the brain." This note argues that the present theory of informed consent is inadequate for such cases and proposes a new theory. (JT)

  15. 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)

  16. 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)

  17. The Perfect Politician

    ERIC Educational Resources Information Center

    Berry, John N., III

    2010-01-01

    The perfect politician, the ideal political ally to a library, is often but not always an elected official. He or she is always an effective champion of "reasonable financial support," i.e., "the amount...which a thoroughly competent librarian can spend wisely." That is what J.T. Wyer, director of the New York State Library, said in his "What the

  18. 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)

  19. Pure Mathematics in Australia

    ERIC Educational Resources Information Center

    Bloom, W. R.; And Others

    1975-01-01

    Reports a survey concerned with the future of mathematics in Australia which identified the number of "experts" in particular areas of mathematics who are working in Australia. Findings show increased research work in the past five years but conclusions indicate that many mathematical areas continue to be neglected. (JT)

  20. Social Work in the Police Agency: Implications for Education and Practice

    ERIC Educational Resources Information Center

    Treger, Harvey

    1976-01-01

    Issues uncovered in a 3-year action-research project that placed social workers and graduate students in community police departments were selection of staff and students, attitudes about the law, confidentiality, motivating the reluctant client, and sensitivity to police-social worker perceptions of each other. (JT)

  1. The Perfect Politician

    ERIC Educational Resources Information Center

    Berry, John N., III

    2010-01-01

    The perfect politician, the ideal political ally to a library, is often but not always an elected official. He or she is always an effective champion of "reasonable financial support," i.e., "the amount...which a thoroughly competent librarian can spend wisely." That is what J.T. Wyer, director of the New York State Library, said in his "What the…

  2. Challenges to Legitimacy: Dilemmas and Directions

    ERIC Educational Resources Information Center

    Yarmolinsky, Adam

    1976-01-01

    Three options are discussed for institutional responses to pressures from clients (students), competitors, taxpayers, citizen activists, and faculty: (1) to concentrate on the preservation of traditional values; (2) to maximize growth in new markets; or (3) to seek a new educational synthesis. (JT)

  3. 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)

  4. 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)

  5. 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)

  6. The Rockford Experience: Competency-Based Medical Curriculum

    ERIC Educational Resources Information Center

    Quinlan, Thomas H.

    1975-01-01

    Describes the process of developing a competency-based curriculum (faculty-developed and time-variable) used at the Rockford School of Medicine created by the State Board of Higher Education of the University of Illinois in 1969. Includes an abstracted sample of a curriculum statement and the curriculum validation process used. (JT)

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

    NASA Astrophysics Data System (ADS)

    Tirone, M.

    2015-09-01

    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.

  8. 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)

  9. 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)

  10. 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.

  11. Student Attrition in North American Veterinary Schools

    ERIC Educational Resources Information Center

    Hooper, Billy E.; Brown, Roger E.

    1975-01-01

    Data presented shows a progressive reduction in North American veterinary student attrition from 12.8 percent in 1966 to 3.1 percent in 1974. The prediction is that with improved selection procedures and time-variable instructional programs the rate will drop and stabilize at approximately two percent. (JT)

  12. 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)

  13. Body Donations in Israel

    ERIC Educational Resources Information Center

    Nathan, Hilel

    1975-01-01

    The success of a program to stimulate bequeathals of bodies for use in teaching anatomy is analyzed: Type of publicity and manner in which the bodies are cared for stimulate most doners, the majority of which are well educated Jews of European background, a high percentage professionals. (JT)

  14. Recent Developments in Student Affairs

    ERIC Educational Resources Information Center

    Holloway, John P.

    1974-01-01

    The rapid development and application to universities and colleges of the constitutional principles of the First Amendment are analyzed with special reference to Healy v. James and its present and possible future ramifications in the area of student affairs including use of university facilities, student conduct, and organizational activities. (JT)

  15. Treatment of Severe Obstructive Sleep Apnea Syndrome with a Chinstrap

    PubMed Central

    Vorona, Robert D.; Ware, J. Catesby; Sinacori, John T.; Ford, Melvin L.; Cross, J. Parker

    2007-01-01

    A chinstrap alone improved severe obstructive sleep apnea as well as or better than the use of CPAP. Citation: Vorona RD; Ware JC; Sinacori JT; Ford ML; Cross JP. Treatment of severe obstructive sleep apnea syndrome with a chinstrap. J Clin Sleep Med 2007;3(7):729730. PMID:18198808

  16. Selecting a Few Residents from Many Applicants: A New Way to be Fair and Efficient

    ERIC Educational Resources Information Center

    Gordon, Michael J.; Lincoln, John A.

    1976-01-01

    Describes a system which utilizes computer analysis for rating and weighting resident selection variables to reduce random error and bias in the ranking of applicants. The result was satisfactory selection with significant savings of time and effort for the residency program faculty. (JT)

  17. Faculty Ratings of Course Evaluation Items

    ERIC Educational Resources Information Center

    Francis, John B.

    1976-01-01

    Instructors whose teaching was evaluated by students rated how applicable the evaluation items were to their classes. Results show that while weighting composite evaluation scores by means of faculty applicability judgments does not affect those overall scores, the distributions of certain items may be altered. (Editor/JT)

  18. Significant Labor Decisions--An Analysis

    ERIC Educational Resources Information Center

    Polhemus, Graig E.

    1977-01-01

    Major labor cases decided during 1976 did not project a clear or simple path for further Constitutional and statutory interpretation, but the year's labor decisions did reveal a new willingness on the part of the U.S. Supreme Court to depart from earlier views of Constitutional law. (JT)

  19. 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)

  20. Electron-phonon coupling in the self-consistent Born approximation of the t-J model

    NASA Astrophysics Data System (ADS)

    Gunnarsson, O.; Rsch, O.

    2006-05-01

    We study an undoped t-J model with electron-phonon interaction using the self-consistent Born approximation (SCBA). By neglecting vertex corrections, the SCBA solves a boson-holon model, where a holon couples to phonons and magnons. Comparison with exact diagonalization results for the t-J model suggests that the SCBA describes the electron-phonon interaction fairly accurately over a substantial range of J/t values. Exact diagonalization of the boson-holon model shows that the deviations are mainly due to the neglect of vertex corrections for small J/t and due to the replacement of the t-J model by the boson-holon model for large J/t . For typical values of J/t , the electron-phonon part ?ep of the electron self-energy has comparable contributions from the second-order diagram in the electron-phonon interaction and a phonon-induced change of magnon diagrams. A very simple approximation to ?ep gives a rather accurate effective mass. Using this approximation, we study the factors influencing the electron-phonon interaction. Typically, we find that the magnons nominally have a stronger coupling to the holon than the phonons. The phonons, nevertheless, drive the formation of small polarons (self-localization) due to important differences between the character of the phonon and magnon couplings.

  1. 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)

  2. The Role of the Humanities in the African University Tomorrow

    ERIC Educational Resources Information Center

    Diarrassouba

    1974-01-01

    After reviewing the historical and potential place of the humanities in African education, the author advocates an educational model in which the humanities would be limited in the vertical plane (i.e. over-specialization discouraged) but expanded horizontally into other university departments. [Article is in both English and French.] (JT)

  3. Student Expression on Campus and Interference with the "Rights of Others"

    ERIC Educational Resources Information Center

    Seymour, Richard G.

    1974-01-01

    In light of related decisions, the author examines the issues involved in Williams v. Eaton, a civil rights suit filed by black athletes at the University of Wyoming upon dismissal from the team for action related to the wearing of armbands in contests with Brigham Young University to protest Morman Church racial policy. (JT)

  4. Design & simulation of in-plane MEMS Lorentz force magnetometer

    NASA Astrophysics Data System (ADS)

    Jyoti, Aditi, Tripathi, C. C.; Gopal, Ram

    2016-03-01

    This report presents the design and simulation of a MEMS based In-plane Lorentz Force Magnetometer (I-LFM), simulated for 8 um UV-LIGA technology using FEM tool of COMSOL Multiphysics 4.3b. Designed I-LFM was simulated in the magnetic field range varied from 1 μJT to 100μJT. The proposed structure composed of a comb drive actuator, configured such that the fingers overlap with each other to generate capacitive coupling for its actuation. The magnetic field can be detected in Z-axis by this comb drive structure. The device was excited by supplying the sinusoidal current with the frequency equivalent to resonance frequency of the device at its first mode i.e. 12.047 kHz. In order to achieve the maximum mechanical output, the device was operated at the resonant frequency. Simulations based results shows a good linearity in the magnetic field range of 1 μJT to 100 μJT with a high quality factor of 130.

  5. 78 FR 5774 - Technical Advisory Committees; Notice of Recruitment of Private-Sector Members

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... send a copy of your resume to Ms. Yvette Springer at Yvette.Springer@bis.doc.gov . Deadline: This... FURTHER INFORMATION CONTACT: Ms. Yvette Springer on (202) 482-2813. Dated: January 22, 2013. Yvette Springer, Committee Liaison Officer. BILLING CODE 3510-JT-P...

  6. 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...

  7. 77 FR 2271 - Technical Advisory Committees; Notice of Recruitment of Private-Sector Members

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ... send a copy of your resume to Ms. Yvette Springer at Yvette.Springer@bis.doc.gov . Deadline: This... FURTHER INFORMATION CONTACT: Ms. Yvette Springer on (202) 482-2813. Dated: January 11, 2012. Yvette Springer, Committee Liaison Officer. BILLING CODE 3510-JT-P...

  8. DTP | Toxicology and Pharmacology Branch (TPB)

    Cancer.gov

    Donzanti, B.A., J.S. Driscoll, J.E. Tomaszewski, J.S. Roth, P. Tosca, M. Placke, A. Singer, J.T. Yarrington and J.A. Kelley, 1994. Acute Cardiotoxicity of the Anti-HIV Dideoxynucleoside, F-ddA, in the Rat. Fund. Appl. Toxicol., 27, 167-176.

  9. 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 ?-1, 3-glucanase activity (9.94 n kat ml(-1)) when compared to all other isolates. Isolate ThJt1 showed second highest activity of ?-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

  10. Gifford-McMahon/Joule-Thomson cryocooler with high-flow-conductance counterflow heat exchanger for use in resistance thermometer calibration

    NASA Astrophysics Data System (ADS)

    Shimazaki, Takeshi; Toyoda, Keishi; Tamura, Osamu

    2006-03-01

    A cryocooler that consists of a two-stage Gifford-McMahon (GM) mechanical refrigerator and a Joule-Thomson (JT) expansion circuit is developed for use in resistance thermometer calibration. The cryocooler is designed to attain a lower temperature rather than to produce a higher cooling power. A simple but high-performance counterflow heat exchanger is developed for the cryocooler. The heat exchanger has a high flow conductance while maintaining a high heat exchange efficiency. It is an improved type of counterflow heat exchanger composed of a spiral capillary and a thin-wall straight outer tube. The developed cryocooler uses a single counterflow heat exchanger not like a conventional GM/JT cryocooler, which usually has two or three counterflow heat exchangers. He4 is used as the working fluid for the JT expansion circuit. The pot where the condensed He4 collects after the JT expansion can reach 1.3K in the continuous operation mode and 1.0K in the single-cycle operation mode. The cooling power of the cryocooler is 580?W at 1.34K with a molar flow rate of 300?mol/s. Temperature control of the pot was demonstrated from 1.4to12K using two control methods. One method involves controlling the evacuation speed in the JT circuit and the other involves controlling the heat input from a heater to the pot. The temperature of the pot is controlled within the order of magnitude of 2mK from peak to peak with either method.

  11. The C-Terminal 88 Amino Acids of the Sendai Virus P Protein Have Multiple Functions Separable by Mutation

    PubMed Central

    Tuckis, Jeffery; Smallwood, Sherin; Feller, Joyce A.; Moyer, Sue A.

    2002-01-01

    The Sendai virus P-L polymerase complex binds the NP-encapsidated nucleocapsid (NC) template through a P-NP interaction. To identify P amino acids responsible for binding we performed site-directed mutagenesis on the C-terminal 88 amino acids in the NC binding domain. The mutant P proteins expressed from plasmids were assayed for viral RNA synthesis and for various protein-protein interactions. All the mutants formed P oligomers and bound to L protein. While two mutants, JT3 and JT8, retained all P functions at or near the levels of wild-type (wt) P, three othersJT4, JT6, and JT9were completely defective for both transcription and genome replication in vitro. Each of the inactive mutants retained significant NC binding but had a different spectrum of other binding interactions and activities, suggesting that the NC binding domain also affects the catalytic function of the polymerase. NC binding was inhibited by combinations of the inactive mutations. The remaining P mutants were active in transcription but defective in various aspects of genome replication. Some P mutants were defective in NP0 binding and abolished the reconstitution of replication from separate P-L and NP0-P complexes. In some of these cases the coexpression of the wt polymerase with the mutant NP0-P complex could rescue the defect in replication, suggesting an interaction between these complexes. For some P mutants replication occurred in vivo, but not in vitro, suggesting that the intact cell is providing an unknown function that cannot be reproduced in extracts of cells. Thus, the C-terminal region of P is complex and possesses multiple functions besides NC binding that can be separated by mutation. PMID:11739672

  12. Temperature instability comparison of micro- and mesoscale Joule-Thomson cryocoolers employing mixed refrigerants

    NASA Astrophysics Data System (ADS)

    Bradley, Peter; Radebaugh, Ray; Lewis, R. J.; Lin, M.-H.; Lee, Y. C.

    2012-06-01

    Previously we demonstrated cryogenic cooling in a Joule-Thomson (JT) microcryocooler (MCC) with mixed refrigerants operating at pressure ratios of 16:1 that achieved stable temperatures of 140 K, with transient temperatures down to 76 K, with precooling of the refrigerant to 240 K. Pre-cooling improves the minimum enthalpy difference, (?hhT)min compared with that of pure fluids. Micro-scale compressors have been unavailable to meet 16:1 ratios. By reducing the ratio to 4:1, mini-compressors become viable in the near term. Utilizing mixed refrigerants optimized for 4:1 pressure ratios we compare the performance stability of this micro-JT employing a 25 mm long multichannel glass fiber heat exchanger (outer low-pressure capillary ID/OD=536 ?m/617 ?m, inner high-pressure channels ID/OD=75 ?m/125 ?m) with a scaled up (meso-scopic) version employing a 20 cm long single channel stainless steel heat exchanger (outer low pressure channel ID/OD=580 ?m/760 ?m, inner high pressure channel ID/OD=150 ?m/266 ?m). This easy to fabricate and modify meso-scale version was fabricated to investigate the temperature instabilities of mixed refrigerants for similar operating conditions but for proportionally higher flows of ~ 30 cm3/min compared with ~ 10 cm3/min. We compare measured pressures, flow rates, temperatures, and stabilities for both micro- and meso-JT cryocoolers to better understand the causes for the temperature instabilities within the micro-JT cryocooler. KEYWORDS: Cryocooler, Joule-Thomson, microcryocooler, micro-JT, mixed

  13. Featured Image: The Q Continuum Simulation

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Each frame in this image (click for the full view!) represents a different stage in the simulated evolution of our universe, ending at present day in the rightmost panel. In a recently-published paper, Katrin Heitmann (Argonne National Laboratory) and collaborators reveal the results from and challenges inherent in the largest cosmological simulation currently available: the Q Continuum simulation. Evolving a volume of (1300 Mpc)3, this massive N-body simulation tracks over half a trillion particles as they clump together as a result of their mutual gravity, imitating the evolution of our universe over the last 13.8 billion years. Cosmological simulations such as this one are important for understanding observations, testing analysis pipelines, investigating the capabilities of future observing missions, and much more. For more information and the original image (as well as several other awesome images!), see the paper below.Citation:Katrin Heitmann et al 2015 ApJS 219 34. doi:10.1088/0067-0049/219/2/34

  14. Featured Image: The Q Continuum Simulation

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    Each frame in this image (click for the full view!) represents a different stage in the simulated evolution of our universe, ending at present day in the rightmost panel. In a recently-published paper, Katrin Heitmann (Argonne National Laboratory) and collaborators reveal the results from and challenges inherent in the largest cosmological simulation currently available: the Q Continuum simulation. Evolving a volume of (1300 Mpc)3, this massive N-body simulation tracks over half a trillion particles as they clump together as a result of their mutual gravity, imitating the evolution of our universe over the last 13.8 billion years. Cosmological simulations such as this one are important for understanding observations, testing analysis pipelines, investigating the capabilities of future observing missions, and much more. For more information and the original image (as well as several other awesome images!), see the paper below.Citation:Katrin Heitmann et al 2015 ApJS 219 34. doi:10.1088/0067-0049/219/2/34

  15. Assessment of physical fitness and exercise tolerance in children with developmental coordination disorder.

    PubMed

    Farhat, Faial; Hsairi, Ines; Baiti, Hamza; Cairney, John; Mchirgui, Radhouane; Masmoudi, Kaouthar; Padulo, Johnny; Triki, Chahinez; Moalla, Wassim

    2015-01-01

    Children with developmental coordination disorder (DCD) have been shown to be less physically fit when compared to their typically developing peers. The purpose of the present study was to examine the relationships among body composition, physical fitness and exercise tolerance in children with and without DCD. Thirty-seven children between the ages of 7 and 9 years participated in this study. Participants were classified according to results obtained on the Movement Assessment Battery for Children (MABC) and were divided in 2 groups: 19 children with DCD and 18 children without DCD. All children performed the following physical fitness tests: The five-jump test (5JT), the triple-hop distance (THD) and the modified agility test (MAT). Walking distance was assessed using the 6-min walking test (6MWT). Children with DCD showed higher scores than children without DCD in all MABC subscale scores, as well as in the total score (p<0.001). Participants with DCD were found to perform significantly worse on the MAT (p<0.001), the THD (p<0.001) and 5JT (p<0.05). Moreover, children with DCD had poorer performance on the 6MWT than children without DCD (p<0.01). Our results found significant correlations among body mass index (BMI), THD (r=0.553, p<0.05), 5JT (r=0.480, p<0.05) and 6MWT (r=0.544, p<0.05) only in DCD group. A significant correlation between MAT and 5JT (r=-0.493, p<0.05) was found. Similarly, THD and 5JT (r=0.611, p<0.01) was found to be correlated in children with DCD. We also found relationships among 6MWT and MAT (r=-0.522, p<0.05) and the 6MWT and 5JT (r=0.472, p<0.05) in DCD group. In addition, we found gender specific patterns in the relationship between exercise tolerance, explosive strength, power, DCD, and BMI. In conclusion, the present study revealed that BMI was indicative of poorer explosive strength, power and exercise tolerance in children with DCD compared to children without DCD probably due to a limited coordination on motor control. PMID:26263407

  16. Effect of forward velocity on the noise characteristics of dual-flow jet nozzles

    NASA Technical Reports Server (NTRS)

    Reed, D. H.

    1974-01-01

    Acoustic results of jet noise tests conducted on scale-model nozzles at a wall isolation facility are presented and analyzed. The test fixture featured a triple-flow system for the purpose of simulating freestream flow around hot dual-flow jet nozzles. Test nozzles included 1/20th scale models of the exhaust system for the JT8D-9 engine, power plant for the Boeing 727 airplane (bypass ratio 1) and of the JT8D-109 refan engine (bypass ratio 2). It was found that overall jet noise is reduced by the forward velocity in proportion to the fifth and sixth power of the relative primary jet velocity. Spectral and directivity characteristics are presented.

  17. 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.

  18. Experimental clean combustor program: Noise study

    NASA Technical Reports Server (NTRS)

    Sofrin, T. G.; Riloff, N., Jr.

    1976-01-01

    Under a Noise Addendum to the NASA Experimental Clean Combustor Program (ECCP) internal pressure fluctuations were measured during tests of JT9D combustor designs conducted in a burner test rig. Measurements were correlated with burner operating parameters using an expression relating farfield noise to these parameters. For a given combustor, variation of internal noise with operating parameters was reasonably well predicted by this expression but the levels were higher than farfield predictions and differed significantly among several combustors. For two burners, discharge stream temperature fluctuations were obtained with fast-response thermocouples to allow calculation of indirect combustion noise which would be generated by passage of the temperature inhomogeneities through the high pressure turbine stages of a JT9D turbofan engine. Using a previously developed analysis, the computed indirect combustion noise was significantly lower than total low frequency core noise observed on this and several other engines.

  19. Spectroscopic determination of kinetic parameters for frequency sweeping Alfven eigenmodes

    SciTech Connect

    Lesur, M.; Idomura, Y.; Shinohara, K.; Garbet, X.

    2010-12-15

    A method for analyzing fundamental kinetic plasma parameters, such as linear drive and external damping rate, based on experimental observations of chirping Alfven eigenmodes, is presented. The method, which relies on new semiempirical laws for nonlinear chirping characteristics, consists of fitting procedures between the so-called Berk-Breizman model and the experiment in a quasiperiodic chirping regime. This approach is applied to the toroidicity induced Alfven eigenmode (TAE) on JT-60 Upgrade (JT-60U) [N. Oyama et al., Nucl. Fusion 49, 104007 (2009)], which yields an estimation of the kinetic parameters and suggests the existence of TAEs far from marginal stability. Two collision models are considered, and it is shown that dynamical friction and velocity-space diffusion are essential to reproduce nonlinear features observed in experiments. The results are validated by recovering measured growth and decay of perturbation amplitude and by estimating collision frequencies from experimental equilibrium data.

  20. 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.

  1. Review of polyhedral distortions as a multi-scale minimization of the electric polarization and their correlations with physical properties.

    PubMed

    Benabbas, Abderrahim

    2006-02-01

    The Jahn-Teller (JT) and non-Jahn-Teller polyhedral distortions are reviewed within the same context, based on a multi-scale minimization of the electric polarization by handling formal ionic valences and valence electron density. This model is applied to tetragonal distortions of octahedra, particularly in K2NiF4 structures with different formula types, along with doping. The predictions are always in good agreement with the observed data. In particular, the ferrodistortive order of JT distortions is obtained from formal charge polarizations, while the antiferrodistortive one is adopted when only the valence electron density is involved. The correlations between physical properties and octahedral elongations through the crystal structures on one side and chemical compositions on the other side are discussed according to this model for high-Tc cuprate superconductors and CMR manganites. PMID:16434788

  2. 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.

  3. 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.

  4. 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.

  5. Normal QT dispersion in colchicine-resistant familial Mediterranean fever (FMF).

    PubMed

    Nussinovitch, Udi; Livneh, Avi; Volovitz, Benjamin; Nussinovitch, Moshe; Ben-Zvi, Ilan; Lidar, Merav; Nussinovitch, Naomi

    2012-07-01

    The association between familial Mediterranean fever (FMF) and subclinical cardiac disease remains controversial. The aim of the current study was to evaluate whether FMF patients, who do not respond to colchicine treatment, and thereby endure persistent inflammation, have increased QT dispersion (QTd) values. Twenty-two FMF patients and 22 age- and sex-matched control subjects were included in the study. Repolarization and QT dispersion parameters were computed from 12-lead ECG recording using designated computer software, and results of five beats were subsequently averaged. Both FMF patients and controls had similar comorbidities, similar values of average QT, average corrected QT interval length, average QTd interval, average QT corrected dispersion, QT dispersion ratio, JT dispersion (JTd), and JT corrected dispersion. In conclusion, FMF patients who were unresponsive to colchicine treatment and did not develop amyloidosis had normal QTd and JTd parameters, indicating a non-increased risk for repolarization-associated ventricular arrhythmias. PMID:22526475

  6. Localized electron heating by strong guide-field magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Guo, Xuehan; Inomoto, Michiaki; Sugawara, Takumichi; Yamasaki, Kotaro; Ushiki, Tomohiko; Ono, Yasushi

    2015-10-01

    Localized electron heating of magnetic reconnection was studied under strong guide-field using two merging spherical tokamak plasmas in the University of Tokyo Spherical Tokamak experiment. Our new slide-type two-dimensional Thomson scattering system is documented for the first time the electron heating localized around the X-point. Shape of the high electron temperature area does not agree with that of energy dissipation term Et.jt . If we include a guide-field effect term Bt/(Bp+αBt) for Et.jt , the energy dissipation area becomes localized around the X-point, suggesting that the electrons are accelerated by the reconnection electric field parallel to the magnetic field and thermalized around the X-point.

  7. Phase Diagram of Doped t-J Ladders

    NASA Astrophysics Data System (ADS)

    Mller, Thierry; Haas, Stephan; Rice, T. M.

    1997-03-01

    Undoped cuprate ladders are known to have ground states which sensitively depend on their width, i.e. even-leg ladders are spin liquids while odd-leg ladders have power law order like in a single chain. At finite hole densities a robust Luther-Emery phase with strong d_x^2 - y^2 superconducting correlations is found close to half-filling for ladders with two legs. However, for sufficiently small J/t gapless spin modes appear which signals a transition to a Luttinger liquid state. The variation of the critical value of J/t for this transition with hole doping is determined from the properties of finite clusters calculated by Lanczos techniques. Upon doping three-leg ladders with holes, a Luttinger liquid phase occurs with only single transverse channels for holons and spinons. A critical hole density is identified beyond which more transverse channels appear, leading to a change in the electronic properties.

  8. 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.

  9. Polarization structure and variability of the BL Lac object S4 0954+658

    NASA Astrophysics Data System (ADS)

    Kudryavtseva, N.; Gabuzda, D.; Mahmud, M.; O'Sullivan, S.

    We present the results of a multi-frequency analysis of the enigmatic BL Lac object S4 0954+658. We have analyzed three epochs of dense VLBA observations with full polarization at 22 GHz and 8 GHz and one epoch at four frequencies 5 GHz, 8 GHz, 15 GHz, and 22 GHz taken in 1996-1998. We found that the jet is of a prominent helical shape and that the jet ridge line changes dramatically with time. The jet ridge line becomes wider with time and the position of the jet ridge line bend shifts along the jet with a speed of 1.50.1 c. The Kelvin-Helmholtz instability can explain such changes of the jet ridge line. We estimate the sound speed of the S4 0954+658 jet a_jt = 0.5 0.1c and the Mach number M_jt = 10 0.7.

  10. 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.

  11. The pollution reduction technology program for can-annular combustor engines - Description and results

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    Pollutant reduction and performance characteristics were determined for three successively more advanced combustor concepts. Program Element I consisted of minor modifications to the current production JT8D combustor and fuel system to evaluate means of improved fuel preparation and changes to the basic airflow distribution. Element II addressed versions of the two-staged Vorbix (vortex burning and mixing) combustor and represented a moderate increase in hardware complexity and difficulty of development. The concept selected for Element III employed vaporized fuel as a means of achieving minimum emission levels and represented the greatest difficulty of development and adaptation to the JT8D engine. Test results indicate that the Element I single-stage combustors were capable of dramatic improvement in idle pollutants. The multistage combustors evaluated in Program Elements II and III simultaneously reduced CO, THC and NOx emissions, but were unable to satisfy the current 1979 EPA standards.

  12. Dynamic Jahn-Teller Effect in Negatively Charged Nitrogen-Vacancy Center in Diamond

    NASA Astrophysics Data System (ADS)

    Abtew, Tesfaye; Zhang, Peihong

    2011-03-01

    The negatively charged nitrogen-vacancy (NV) center in diamond has attracted much research interest recently owing to its desirable optical properties and long spin coherent lifetime. The ground state of NV- center has a 3 A2 symmetry, which can be optically excited, to a 3 E state. The excited state is orbitally degenerate therefore should experience either static or dynamic Jahn-Teller (JT) effects. We use accurate first-principles methods to study structural and electronic properties of the NV- center in diamond both in the ground and excited states. Our results indicate that the excited state of the NV- center is indeed a dynamic JT system. We acknowledge the Center for Computational Research at the University at Buffalo, SUNY. This work is supported by the National Science Foundation under Grant No. DMR-0946404 and by the Department of Energy under GrantNo. DE-SC0002623.

  13. 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.

  14. An improved method for predicting the effects of flight on jet mixing noise

    NASA Technical Reports Server (NTRS)

    Stone, J. R.

    1979-01-01

    The NASA method (1976) for predicting the effects of flight on jet mixing noise was improved. The earlier method agreed reasonably well with experimental flight data for jet velocities up to about 520 m/sec (approximately 1700 ft/sec). The poorer agreement at high jet velocities appeared to be due primarily to the manner in which supersonic convection effects were formulated. The purely empirical supersonic convection formulation of the earlier method was replaced by one based on theoretical considerations. Other improvements of an empirical nature included were based on model-jet/free-jet simulated flight tests. The revised prediction method is presented and compared with experimental data obtained from the Bertin Aerotrain with a J85 engine, the DC-10 airplane with JT9D engines, and the DC-9 airplane with refanned JT8D engines. It is shown that the new method agrees better with the data base than a recently proposed SAE method.

  15. 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.

  16. Low activation austenitic Mn-steel for in-vessel fusion materials

    NASA Astrophysics Data System (ADS)

    Suzuki, Y.; Saida, T.; Kudough, F.

    1998-10-01

    Several compositions of austenitic manganese steels (Mn-steels) were investigated for in-vessel component materials in D-T fueled fusion reactor with respect to radiation exposure and waste disposal management. The 24.5Mn-13.5Cr steel was developed in which undesired impurities, such as Ni, Mo, Nb and Co, were controlled and C (0.025wt%) and N (0.22wt%) contents were well adjusted for corrosion resistance and weldability. Experimental observation has shown that this steel has a single ?-phase structure and good properties for vacuum vessel almost the same grade as Type 316 stainless steel (316SS), such as low permeability, good weldability, good mechanical properties of strength and toughness and good corrosion resistance. Activation calculations were performed adopting this material for the JT-60 Super Upgrade (JT-60SU) vacuum vessel and the effectiveness of low activation was confirmed.

  17. Tunneling in Jahn-Teller Systems and Multidimensional WKB Approximation

    NASA Astrophysics Data System (ADS)

    Polinger, Victor

    We develop a general WKB approach to multidimensional tunneling in Jahn-Teller (JT) systems. To solve the path branching problem, we introduce the so-called junction rule for nodes in a multidimensional web of tunneling paths connecting equivalent wells. For any complex JT system, it provides enough equations to reduce the multidimensional tunneling to one-dimensional penetration through just one potential barrier. The junction rule is shown to include the symmetry properties of the ground-state wave function, same as the operator of symmetry projection. The tunneling splitting energy gap is shown to be proportional to probability flux through the bottle-neck point of the potential barrier, where it is highest. The order of energy levels in the ground-state tunneling multiplet is determined by the factor cos [phi]B, where [phi]B is the corresponding Berry phase. Several examples of practical interest are considered in detail.

  18. 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.

  19. Optimization of the working fluid for a sorption-based Joule-Thomson cooler

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Zalewski, D. R.; Vermeer, C. H.; ter Brake, H. J. M.

    2013-12-01

    Sorption-based Joule-Thomson coolers operate vibration-free, have a potentially long life time, and cause no electromagnetic interference. Therefore, they are appealing to a wide variety of applications, such as cooling of low-noise amplifiers, superconducting electronics, and optical detectors. The required cooling temperature depends on the device to be cooled and extends into the cryogenic range well below 80 K. This paper presents a generalized methodology for optimization in a sorption-based JT cooler. The analysis is based on the inherent properties of the fluids and the adsorbent. By using this method, the working fluid of a JT cooler driven by a single-stage sorption compressor is optimized for two ranges of cold-tip operating temperatures: 65-160 K and 16-38 K. The optimization method is also extended to two-stage compression and specifically nitrogen and carbon monoxide are considered.

  20. Development of a microminiature sorption cooler

    NASA Technical Reports Server (NTRS)

    Burger, Johannes; Holland, Harry; terBrake, Marcel; Rogalla, Horst; Wade, Larry

    1997-01-01

    The development of a microcooler for operations below 80 K, for low temperature electronic devices requiring small cooling powers of the order of 10 mW is described. A sorption compressor combined with Joule-Thomson (JT) expansion was selected for miniaturization. The advantage of the system is considered to be its absence of moving parts, with the exception of the check valves. This facilitates the scaling down of the system, minimizes interferences and contributes to a long lifetime. The requirements for small scale cooling of low temperature electronics are listed. The sorption compressor and the JT expansion are described. A parameter study is reviewed together with the scaling of the sorption compressor.

  1. Investigations on two-phase heat exchanger for mixed refrigerant Joule-Thomson cryocooler

    NASA Astrophysics Data System (ADS)

    Ardhapurkar, Purushottam; Sridharan, Arunkumar; Atrey, Milind

    2012-06-01

    The design of the recuperative heat exchanger used to pre-cool the refrigerant mixture prior to J-T expansion is crucial for the efficient operation of the mixed refrigerant Joule- Thomson (MR J-T) cryocooler. The multi-component non-azeotropic refrigerant mixture undergoes boiling and condensation heat transfer simultaneously in the heat exchanger. Therefore, it is important to analyze the performance of the heat exchanger in terms of temperature distribution with respect to the mixture of gases used. In the present work, temperature measurements are carried out at the ends of the heat exchanger for high pressure stream, while eight sensors are installed at equal distance along the length of heat exchanger to measure temperature of low pressure stream. The paper reports variation in heat transfer coefficient along the length of the heat exchanger. The variation is discussed with respect to temperature distribution across the length and changes in thermo-physical properties of the gas mixture.

  2. Hydraulic characteristics and thermal counterflow in helium II forced flow through orifice plates

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Jin; Van Sciver, Steven

    2012-06-01

    The purpose of the present research is to measure and anlyze the temperature changes and the pressure difference variations through orifice plates in superfluid helium bellows pump through a 1 m long, 73 mm inner diameter experimental channel containing Reynolds number is between 3.0 X 106 and 1.2 X 107. The hydraulic characteristics for adiabatic forced flow He II are examined by comparing with measured pressure drops across the orifice plates to correlations for classical fluids at high Reynolds number. The temperature rise through the orifice plate due to the Joule-Thomson (JT) effect in He II forced flow was also measured. Results are compared to the previous results of the experiment with the 10% orifice and expected temperature changes based on known values for the JT Coefficient to investigate the effect of He II thermal counterflow through the orifice.

  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. The vibronic effects in the excited 1 1E u state of (CO) 4 dianion in terms of time dependent (TD) density functional theory: The resonance and pre-resonance Raman studies

    NASA Astrophysics Data System (ADS)

    Zazakowny, Piotr; Makowski, Marcin; Pawlikowski, Marek T.

    2006-02-01

    Franck-Condon (FC) and Jahn-Teller (JT) effects in the 1 1E u state of the (CO) 4 dianion are examined in terms of time dependent density functional theory (TD DFT) at the B3LYP/6-31G+* level. The experimental absorption, pre-resonance and resonance Raman spectra associated with 1A g ? 1 1E u(??*) transition are studied. The computations indicate considerable activities of ?5(b 2g) = 1073 cm -1 (CC stretching) and ?10(b 1g) = 624 cm -1 (ring bending) modes due to JT effect in the 1 1E u(??*). Of two totally symmetric modes of the squarate dianion only single ?2(a 1g) = 698 cm -1 (ring breathing) vibration is shown to exhibit the sizable Franck-Condon activity in the lowest energy 1 1E u(??*) state of the squarate dianion.

  5. 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

  6. Two cases of multiple ossifying fibromas in the jaws

    PubMed Central

    2014-01-01

    Background The clinicopathologic characteristics of multiple ossifying fibroma (OF) are unclear due to the conditions rarity, making diagnosis challenging. Sporadic multiple OFs must be distinguished from hyperparathyroidism-jaw tumour syndrome (HPT-JT) related OF and other fibro-osseous lesions. Methods Multiple OF cases were identified from ossifying fibroma cases. Clinical data including age, sex, anatomic site, radiographic features, clinical impression, treatment and available follow-up data as well as serum calcium, phosphorus, and parathyroid hormone (PTH) were recorded. GNAS and HRPT2 genetic mutations were examined in the two present cases. Case reports of sporadic multiple ossifying fibroma and HPT-JT-related OF were also reviewed. Results The two present cases were confirmed as sporadic multiple OF, with no genetic GNAS and HRPT2 mutations found. The incidence of sporadic multiple ossifying fibroma was 2.0% (2/102). The total 18 sporadic multiform OF cases were characterized as followed: 13 (72.2%) female; 5 (27.8%) male; mean age 28.6years; 2/16 (11.1%) cases only in the mandible; 4/18 (22.2%) cases only in the maxilla; and 12/18 (66.7%) cases in both the maxilla and mandible. Radiographically, the lesions were radiolucent in 5/18 (27.8%) cases and mixed density in 13/18 (72.2%) cases. Along with 24 cases of HPT-JT related OF were reviewed, sixteen (66.7%) patients were diagnosed with a single lesion, and 8 patients (33.3%) were diagnosed with multiple jaw lesions. Conclusions Sporadic multiple OFs are very rare, but must be distinguished from HPT-JT related OF. We strongly recommend that patients diagnosed with multiple ossifying fibromas receive serum PTH testing and mutation screening of HRPT2. Virtual slides http://www.diagnosticpathology.diagnomx.eu/vs/1194507146115753 PMID:24678936

  7. 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.

  8. Search for short lived neutral particle in the 15.1 MeV isovector transition of 12C

    NASA Astrophysics Data System (ADS)

    Datar, V. M.; Fortier, S.; Gales, S.; Hourani, E.; Langevin, H.; Maison, J. M.; Massolo, C. P.

    1988-01-01

    We report a search for a short lived neutral particle ? emitted in the decay of the 15.1 MeV J?(T)=1+(1) state in 12C. The experiment is sensitive to ?-->e+e- decays and finds no evidence for such a particle. We set upper limits on ??/?? for mean lifetimes between ~10-13 and ~10-8 sec and in the mass range 1.02-2.5 MeV.

  9. Development of a rotor wake/vortex model. Volume 2: User's manual for computer program

    NASA Technical Reports Server (NTRS)

    Majjigi, R. K.; Gliebe, P. R.

    1984-01-01

    The principal objective was to establish a verified rotor wake/vortex model for specific application to fan and compressor rotor-stator interaction and resulting noise generation. A description and flow chart of the Rotor Wake/Vortex Model computer program, a listing of the program, definitions of the input/output parameters, a sample input/output case, and input files for Rotor 55, the JT15D rotor, and Rotor 67, Stage 1 are provided.

  10. The number of computers in a non-hierarchical system for Tokamak data processing

    NASA Astrophysics Data System (ADS)

    Ogata, Atsushi; Yuasa, Kazuo

    1980-01-01

    The data processing of a tokamak Ohmic heating experiment is summarized by a directed graph. A method which is a modification of the project-management technique PERT is developed and applied to this directed graph to analyse how many computers should be used for the data processing. An estimate of the number of computers is made for the data processor of the large tokamak JT-60.

  11. Summary of the 19th Joint EU-US Transport Task Force Workshop

    NASA Astrophysics Data System (ADS)

    Angioni, C.; Mantica, P.; Naulin, V.; Bourdelle, C.; Hidalgo, C.; Maggi, C. F.; Rice, J. E.; Sharapov, S. E.; 19th Joint EU-US Transport Task Force Workshop, the Participants to the

    2015-06-01

    This conference report summarizes the contributions to, and discussions at, the 19th Joint EU-US Transport Task Force workshop, held in Culham, UK, during 8-11 September 2014. The workshop was organized under six topics: momentum transport, energetic particles, challenges in modelling transport in ITER and JT60-SA, L-H transition, impurity transport and SOL transport. This report follows the same structure.

  12. Utilizing numerical techniques in turbofan inlet acoustic suppressor design

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.

    1982-01-01

    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.

  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. 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.

  15. Status of Fusion Experimental Reactor (FER) design

    SciTech Connect

    Tone, T.; Fujisawa, N.; Sugihara, M.

    1985-07-01

    Conceptual design studies of the Fusion Experimental Reactor (FER) have been conducted at JAERI in line with a long-range plan for fusion reactor development laid out in the long-term program of the Atomic Energy Commission issued in 1982. The FER succeeding the tokamak device JT-60 is a tokamak reactor with a major mission of realizing a self-ignited long-burning DT plasma and demonstrating engineering feasibility. The paper describes recent developments of the FER design concept.

  16. Corrigendum Corrigendum: Association between TAP1 gene polymorphisms and alopecia areata in a Korean population - Genet. Mol. Res. 14 (4): 18820-18827.

    PubMed

    Kim, H K; Lee, H; Lew, B L; Sim, W Y; Kim, Y O; Lee, S W; Lee, S; Cho, I H; Kwon, J T; Kim, H J

    2016-01-01

    H.K. Kim(1)*, H. Lee(1)*, B.L. Lew(2), W.Y. Sim(2), Y.O. Kim(3), S.W. Lee(3), S. Lee(4), I.H. Cho(5), J.T. Kwon(1) and H.J. Kim(1,6) (5)Department of Convergence Medical Science, Brain Korea 21 Plus Program, and Institute of Korean Medicine, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea. PMID:26985926

  17. Spectral flame radiance from a tubular-can combustor

    NASA Technical Reports Server (NTRS)

    Claus, R. W.

    1981-01-01

    An experimental investigation was conducted to determine the effects of fuel type, fuel-air ratio, and inlet-air pressure on the spectral flame radiance emanating from a JT8D can combustor. Spectral radiance measurements from 1.55 to 5.5 micrometers of wavelength were recorded and analyzed to determine soot concentration and flame temperature at various axial locations in the combustor. Two fuels differing in volatility, viscosity, and chemical composition were used in this investigation.

  18. Quadratic coupling treatment of the Jahn-Teller effect in the triply-degenerate electronic state of CH4+: Can one account for floppiness?

    NASA Astrophysics Data System (ADS)

    Mondal, T.; Varandas, A. J. C.

    2012-12-01

    The Jahn-Teller (JT) coupling effects in the triply degenerate ground electronic state of methane radical cation are investigated theoretically within a quadratic vibronic coupling approach. The underlying potential energy surfaces over the two-dimensional space of nuclear coordinates, subject to the T2 ⊗ (e + t2 + t2) Jahn-Teller effect, are established from extensive ab initio calculations using the multi-reference configuration interaction method and then employed to determine the various parameters of a diabatic Hamiltonian of this system. Our previous investigation [T. Mondal and A. J. C. Varandas, J. Chem. Phys. 135, 174304 (2011), 10.1063/1.3658641], relying on the linear vibronic coupling approach augmented by only a diagonal second-order term of the totally symmetric mode, are extended here by including all possible quadratic coupling constants of JT active e and t2 modes. Inclusion of these quadratic couplings is found to be important to reproduce correctly the broad vibrational structure and for a better description of dynamical JT effect in the first vibronic band of this radical cation. The impact of large amplitude motions (which are responsible for floppiness of the molecule) on the vibronic structure and dynamics of the first photoelectron band have been examined via readjustment of their linear coupling parameters up to ±10%.

  19. 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.

  20. 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.