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Sample records for cit compact ignition

  1. Recent progress on the Compact Ignition Tokamak (CIT)

    International Nuclear Information System (INIS)

    This report describes work done on the Compact Ignition Tokamak (CIT), both at the Princeton Plasma Physics Laboratory (PPPL) and at other fusion laboratories in the United States. The goal of CIT is to reach ignition in a tokamak fusion device in the mid-1990's. Scientific and engineering features of the design are described, as well as projected cost and schedule

  2. Recent progress on the Compact Ignition Tokamak (CIT)

    Energy Technology Data Exchange (ETDEWEB)

    Ignat, D.W.

    1987-01-01

    This report describes work done on the Compact Ignition Tokamak (CIT), both at the Princeton Plasma Physics Laboratory (PPPL) and at other fusion laboratories in the United States. The goal of CIT is to reach ignition in a tokamak fusion device in the mid-1990's. Scientific and engineering features of the design are described, as well as projected cost and schedule.

  3. Equilibrium calculations for plasma control in CIT [Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The free-boundary equilibrium code VEQ provides equilibrium data that are used by the Tokamak Simulation Code (TSC) in design and analysis of the poloidal field (PF) system for the Compact Ignition Tokamak (CIT). VEQ serves as an important design tool for locating the PF coils and defining coil current trajectories and control systems for TSC. In this report, VEQ and its role in the TSC analysis of the CIT PF system are described. Equilibrium and coil current calculations are discussed, an overview of the CIT PF system is presented, a set of reference equilibria for modeling a complete discharge in CIT is described, and the concept of a plasma shape control matrix is introduced. 9 refs., 8 figs., 7 tabs

  4. Scattering and localizability of ECH [electron-cyclotron heating] power in CIT [Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The theory of scattering by drift-wave density fluctuations is applied to electron-cyclotron heating (ECH) in the Compact Ignition Tokamak (CIT). It is found for CIT that the scattering angles are small and have a Gaussian distribution. An analytic result is given for the average number of scattering events suffered by a ray during propagation through the turbulence layer; this average number is 1.3 for the turbulence level expected in CIT. Localizability of ECH power in CIT is also studied for two choices of steering mirror. Better access to outer flux surfaces and better localization is achieved if the power is steered within a poloidal plane. 7 refs., 3 figs

  5. Plans for the CIT [Compact Ignition Tokamak] instrumentation and control system

    International Nuclear Information System (INIS)

    Extensive experience with previous fusion experiments (TFTR, MFTF-B and others) is driving the design of the Instrumentation and Control System (I and C) for the Compact Ignition Tokamak (CIT) to be built at Princeton. The new design will reuse much equipment from TFTR and will be subdivided into six major parts: machine control, machine data acquisition, plasma diagnostic instrument control and instrument data acquisition, the database, shot sequencing and safety interlocks. In a major departure from previous fusion experiment control systems, the CIT machine control system will be a commercial process control system. Since the machine control system will be purchased as a completely functional product, we will be able to concentrate development manpower in plasma diagnostic instrument control, data acquisition, data processing and analysis, and database systems. We will discuss the issues driving the design, give a design overview and state the requirements upon any prospective commercial process control system

  6. The CIT [compact ignition tokamak] pellet injection system: Description and supporting research and development

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) will use an advance, high-velocity pellet injection system to achieve and maintain ignited plasmas. Two pellet injectors are provided: a moderate-velocity (1-to 1.5-km/s), single-stage pneumatic injector with high reliability and a high-velocity (4- to 5-km/s), two-stage pellet injector that uses frozen hydrogenic pellets encased in sabots. Both pellet injectors are qualified for operation with tritium feed gas. Issues such as performance, neutron activation of injector components, maintenance, design of the pellet injection vacuum line, gas loads to the reprocessing system, and equipment layout are discussed. Results and plans for supporting research and development (R and D) in the areas of tritium pellet fabrication and high-velocity, repetitive two-stage pneumatic injectors are presented. 7 refs., 4 figs., 2 tabs

  7. TSC [Tokamak Simulation Code] disruption scenarios and CIT [Compact Ignition Tokamak] vacuum vessel force evolution

    International Nuclear Information System (INIS)

    The Tokamak Simulation Code and the TWIR postprocessor code have been used to develop credible plasma disruption scenarios for the Compact Ignition Tokamak (CIT) in order to predict the evolution of forces on CIT conducting structures and to provide results required for detailed structural design analysis. The extreme values of net radial and vertical vacuum vessel (VV) forces were found to be FR=-12.0 MN/rad and FZ=-3.0 MN/rad, respectively, for the CIT 2.1-m, 11-MA design. Net VV force evolution was found to be altered significantly by two mechanisms not noted previously. The first, due to poloidal VV currents arising from increased plasma paramagnetism during thermal quench, reduces the magnitude of the extreme FR by 15-50% and modifies the distribution of forces substantially. The second effect is that slower plasma current decay rates give more severe net vertical VV loads because the current decay occurs when the plasma has moved farther from midplane than is the case for faster decay rates. 7 refs., 9 figs., 1 tab

  8. Dependence of CIT [Compact Ignition Tokamak] PF [poloidal field] coil currents on profile and shape parameters using the Control Matrix

    International Nuclear Information System (INIS)

    The plasma shaping flexibility of the Compact Ignition Tokamak (CIT) poloidal field (PF) coil set is demonstrated through MHD equilibrium calculations of optimal PF coil current distributions and their variation with poloidal beta, internal inductance, plasma 95% elongation, and 95% triangularity. Calculations of the magnetic stored energy are used to compare solutions associated with various plasma parameters. The Control Matrix (CM) equilibrium code, together with the nonlinear equation and numerical optimization software packages HYBRD, and VMCON, respectively, are used to find equilibrium coil current distributions for fixed divertor geometry, volt-seconds, and plasma profiles in order to isolate the dependence on individual parameters. A reference equilibrium and coil current distribution are chosen, and correction currents dI are determined using the CM equilibrium method to obtain other specified plasma shapes. The reference equilibrium is the κ = 2 divertor at beginning of flattop (BOFT) with a minimum stored energy solution for the coil current distribution. The pressure profile function is fixed

  9. Surface erosion and tritium inventory analysis for CIT [Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The expected buildup of co-deposited tritium on the CIT carbon divertor and first wall surfaces and operational methods of minimizing the inventory have been examined. The analysis uses impurity transport computer codes, and associated plasma and tritium retention models, to compute the thickness of redeposited sputtered carbon and the resulting co-deposited tritium inventory on the divertor plates and first wall. Predicted erosion/growth rates are dominated by the effect of gaps between carbon tiles. The overall results appear favorable, showing stable operation (finite self-sputtering) and acceptably low (∼25 Ci/pulse) co-deposited tritium rates, at high surface temperature (1700 degree C) design conditions. These results, however, are highly speculative due to serious model inadequacies at the high sputtering rates predicted. If stable operation is obtainable, the prospects appear good for adequate tritium inventory control via helium-oxygen glow discharge cleaning. 25 refs

  10. Ignition probabilities for Compact Ignition Tokamak designs

    International Nuclear Information System (INIS)

    A global power balance code employing Monte Carlo techniques had been developed to study the ''probability of ignition'' and has been applied to several different configurations of the Compact Ignition Tokamak (CIT). Probability distributions for the critical physics parameters in the code were estimated using existing experimental data. This included a statistical evaluation of the uncertainty in extrapolating the energy confinement time. A substantial probability of ignition is predicted for CIT if peaked density profiles can be achieved or if one of the two higher plasma current configurations is employed. In other cases, values of the energy multiplication factor Q of order 10 are generally obtained. The Ignitor-U and ARIES designs are also examined briefly. Comparisons of our empirically based confinement assumptions with two theory-based transport models yield conflicting results. 41 refs., 11 figs

  11. Cooldown of the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Cooldown of the Compact Ignition Tokamak (CIT) with the baseline liquid nitrogen cooling system was analyzed. On the basis of this analysis and present knowledge of the two-phase heat transfer, the current baseline CIT can be cooled down in about 1.5 h. An extensive heat transfer test program is recommended to reduce uncertainty in the heat transfer performance and to explore methods for minimizing the cooldown time. An alternate CIT cooldown system is described which uses a pressurized gaseous helium coolant in a closed-loop system. It is shown analytically that this system will cool down the CIT well within 1 h. Confidence in this analysis is sufficiently high that a heat transfer test program would not be necessary. The added cost of this alternate system is estimated to be about $5.3 million. This helium cooling system represents a reasonable backup approach to liquid nitrogen cooling of the CIT. 3 refs., 12 figs., 3 tabs

  12. Neutron production rates vs. time during start-up of the tritium-assisted D3He CIT (Compact Ignition Torus) machine

    International Nuclear Information System (INIS)

    Neutron production rates and D3He reaction rate vs. time during tritium-assisted start-up of the D3He fueled CIT machine have been calculated for an operating scenario involving a 3-comoponent D-shaped plasma with variable concentrations of D,T and 3He ions. Neutron calculations have been performed for the DT, DD, TT and T3He (2 branches) fusion reactions. Neutron production rates and D3He reaction rate are reported in graphical form and discussed with reference to the assumed operating scenario. It is found that even at the end of the 7 s start-up, during which the tritium concentration decreases from 20 to 2.75%, the production rate of DT 114 MeV neutrons does not appear to be negligible. The production rate of DT neutrons due to the tritium generated in the protonic branch of the DD reaction (''deuteric'' tritium) is found to be not-negligible in conditions of D3He ignition. Means for reducing this effect are considered. Some general conclusions on tritium-assistance and on cleanness of the D3He fuel cycle are drawn

  13. Overview of tritium systems for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) is being designed at several laboratories to produce and study fully ignited plasma discharges. The tritium systems which will be needed for CIT include fueling systems and radiation monitoring and safety systems. Design of the tritium systems is the responsibility of the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory. Major new tritium systems for CIT include a pellet injector, an air detritiation system and a glovebox atmosphere detritiation system. The pellet injector is being developed at Oak Ridge National Laboratory. 7 refs., 2 figs

  14. Compact ignition tokamak physics and engineering basis

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) is a high-field, compact tokamak design whose objective is the study of physics issues associated with burning plasmas. The toroidal and poloidal field coils employ a copper-steel laminate, manufactured by explosive-bonding techniques, to support the forces generated by the design fields: 10 T toroidal field at the plasma center; 21 T in the OH solenoid. A combination of internal and external PF coils provides control of the equilibrium and the ability to sweep the magnetic separatrix across the divertor plates during a pulse. At temperatures and βα levels characteristic of ITER designs, the fusion power in CIT approaches 800 MW and can be the limiting factor in the pulse length. Ignition requires that the confinement time exceed present L-mode scalings by about a factor of two, which is anticipated to occur as a result of the operational flexibility incorporated into the design. Conventional operating limits given by 20 e and qψ ≤ 3.2 have been chosen and, in the case of MHD limits, have been justified by ideal stability analysis. The power required for CIT ignition ranges from 10 MW to 40 MW or more, depending on confinement assumptions, and either ICRF or ECRF heating, or both, will be used. (author). 17 refs, 6 figs, 1 tab

  15. System studies of compact ignition tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Galambos, J.D.; Blackfield, D.T.; Peng, Y.K.M.; Reid, R.L.; Strickler, D.J.; Selcow, E.

    1987-08-01

    The new Tokamak Systems Code, used to investigate Compact Ignition Tokamaks (CITs), can simultaneously vary many parameters, satisfy many constraints, and minimize or maximize a figure of merit. It is useful in comparing different CIT design configurations over wide regions of parameter space and determining a desired design point for more detailed physics and engineering analysis, as well as for performing sensitivity studies for physics or engineering issues. Operational windows in major radius (R) and toroidal field (B) space for fixed ignition margin are calculated for the Ignifed and Inconel candidate CITs. The minimum R bounds are predominantly physics limited, and the maximum R portions of the windows are engineering limited. For a modified Kaye-Goldston plasma-energy-confinement scaling, the minimum size is 1.15 m for the Ignifed device and 1.25 m for the Inconel device. With the Ignition Technical Oversight Committee (ITOC) physics guidance of B/sup 2/a/q and I/sub p/ >10 MA, the Ignifed and Base-line Inconel devices have a minimum size of 1.2 and 1.25 m and a toroidal field of 11 and 10.4 T, respectively. Sensitivity studies show Ignifed to be more sensitive to coil temperature changes than the Inconel device, whereas the Inconel device is more sensitive to stress perturbations.

  16. System studies of compact ignition tokamaks

    International Nuclear Information System (INIS)

    The new Tokamak Systems Code, used to investigate Compact Ignition Tokamaks (CITs), can simultaneously vary many parameters, satisfy many constraints, and minimize or maximize a figure of merit. It is useful in comparing different CIT design configurations over wide regions of parameter space and determining a desired design point for more detailed physics and engineering analysis, as well as for performing sensitivity studies for physics or engineering issues. Operational windows in major radius (R) and toroidal field (B) space for fixed ignition margin are calculated for the Ignifed and Inconel candidate CITs. The minimum R bounds are predominantly physics limited, and the maximum R portions of the windows are engineering limited. For a modified Kaye-Goldston plasma-energy-confinement scaling, the minimum size is 1.15 m for the Ignifed device and 1.25 m for the Inconel device. With the Ignition Technical Oversight Committee (ITOC) physics guidance of B2a/q and I/sub p/ >10 MA, the Ignifed and Base-line Inconel devices have a minimum size of 1.2 and 1.25 m and a toroidal field of 11 and 10.4 T, respectively. Sensitivity studies show Ignifed to be more sensitive to coil temperature changes than the Inconel device, whereas the Inconel device is more sensitive to stress perturbations

  17. Plasma transport in a Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Nominal predicted plasma conditions in a Compact Ignition Tokamak (CIT) are illustrated by transport simulations using experimentally calibrated plasma transport models. The range of uncertainty in these predictions is explored by using various models that have given almost equally good fits to experimental data. Using a transport model that best fits the data, thermonuclear ignition occurs in a CIT design with a major radius of 1.32 m, plasma half-width of 0.43 mn, elongation of 2.0, and toroidal field and plasma current ramped in 6 s from 1.7 to 10.4 T and 0.7 to 10 MA, respectively. Ignition is facilitated by 20 MW of heating deposited off the magnetic axis near the /sup 3/He minority cyclotron resonance layer. Under these conditions, sawtooth oscillations are small and have little impact on ignition. Tritium inventory is minimized by preconditioning most discharges with deuterium. Tritium is injected, in large frozen pellets, only after minority resonance preheating. Variations of the transport model, impurity influx, heating profile, and pellet ablation rates have a large effect on ignition and on the maximum beta that can be achieved

  18. Physics aspects of the compact ignition tokamak

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) is a proposed modest-size ignition experiment designed to study the physics of alpha particle heating. The basic concept is to achieve ignition in a modest-size minimum cost experiment by using a high plasma density to achieve nτE ≅ 2 x 1020 s/m3 required for ignition. The high density requires a high toroidal field (10 T). The high toroidal field allows a large plasma current (10 MA) which provides a high level of ohmic heating, improves the energy confinement, and allows a relatively high beta (≅ 6%). The present CIT design also has a high degree of elongation (κ ≅ 1.8) to aid in producing the large plasma current. A double null poloidal divertor and pellet injection are part of the design to provide impurity and particle control, improve the confinement, and provide flexibility for improving the plasma profiles. Auxiliary heating is expected to be necessary to achieve ignition, and 10-20 MW of ICRF is to be provided. (orig.)

  19. Physics aspects of the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) is a proposed modest-size ignition experiment designed to study the physics of alpha-particle heating. The basic concept is to achieve ignition in a modest-size minimum cost experiment by using a high plasma density to achieve the condition of ntau/sub E/ ∼ 2 x 1020 sec m-3 required for ignition. The high density requires a high toroidal field (10 T). The high toroidal field allows a large plasma current (10 MA) which improves the energy confinement, and provides a high level of ohmic heating. The present CIT design also has a gigh degree of elongation (k ∼ 1.8) to aid in producing the large plasma current. A double null poloidal divertor and a pellet injector are part of the design to provide impurity and particle control, improve the confinement, and provide flexibility for impurity and particle control, improve the confinement, and provide flexibility for improving the plasma profiles. Since auxiliary heating is expected to be necessary to achieve ignition, 10 to 20 MW of Ion Cyclotron Radio Frequency (ICRF) is to be provided

  20. Physics aspects of the Compact Ignition Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Post, D.; Bateman, G.; Houlberg, W.; Bromberg, L.; Cohn, D.; Colestock, P.; Hughes, M.; Ignat, D.; Izzo, R.; Jardin, S.

    1986-11-01

    The Compact Ignition Tokamak (CIT) is a proposed modest-size ignition experiment designed to study the physics of alpha-particle heating. The basic concept is to achieve ignition in a modest-size minimum cost experiment by using a high plasma density to achieve the condition of ntau/sub E/ approx. 2 x 10/sup 20/ sec m/sup -3/ required for ignition. The high density requires a high toroidal field (10 T). The high toroidal field allows a large plasma current (10 MA) which improves the energy confinement, and provides a high level of ohmic heating. The present CIT design also has a gigh degree of elongation (k approx. 1.8) to aid in producing the large plasma current. A double null poloidal divertor and a pellet injector are part of the design to provide impurity and particle control, improve the confinement, and provide flexibility for impurity and particle control, improve the confinement, and provide flexibility for improving the plasma profiles. Since auxiliary heating is expected to be necessary to achieve ignition, 10 to 20 MW of Ion Cyclotron Radio Frequency (ICRF) is to be provided.

  1. Maintainability features of the compact ignition tokamak

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) is a deuterium-tritium (D-T) device envisaged to be the next experimental reactor in the US Fusion Program. The reactor will initially operate in a nonactivated hydrogen phase for approximately two years. This will permit verification of the integrity of the total system and allow hands-on repair to equipment which has experienced shakedown and early operation failures. Once D-T operations commence, reactor maintenance will require remote handling techniques. An evaluation has been completed to determine what maintenance operations must be performed on the CIT. A maintenance philosophy has been developed which is based upon the use of manipulator systems and robotics in the test cell. Replacement of life-limited equipment will be accomplished using a modular design approach for components, with simple remotely operable interfaces. Examples of operations to be done remotely include: (1) replacing of rf antennae and Faraday shields, (2) uncoupling diagnostic and fueling penetrations, (3) removing of all port covers, and (4) replacing first wall armor tiles, optical mirrors, and vacuum windows

  2. In-vessel remote maintenance of the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) is the first deuterium-tritium (D-T) fusion device that will study the physics of an ignited plasma. The ability of the tokamak vacuum vessel to be maintained remotely while under vacuum has not been fully demonstrated on previous machines, and this ability will be critical to the efficient and safe operation of ignition devices. Although manned entry into the CIT vacuum vessel will be possible during the nonactivated stages of operation, remotely automated equipment will be used to assist in initial assembly of the vessel as well as to maintain all in-vessel components once the D-T burn is achieved. Remote maintenance and operation will be routinely required for replacement of thermal protection tiles, inspection of components, leak detection, and repair welding activities. Conceptual design to support these remote maintenance activities has been integrated with the conceptual design of the in-vessel components to provide a complete and practical remote maintenance system for CIT. The primary remote assembly and maintenance operations on CIT will be accomplished through two dedicated 37- x 100-cm ports on the main toroidal vessel. Each port contains a single articulated boom manipulator (ABM), which is capable of accessing half of the torus. The proposed ABM consists of a movable carriage assembly, telescoping two-part mast, and articulated link sections. 1 ref

  3. Pulse length assessment of compact ignition tokamak designs

    International Nuclear Information System (INIS)

    A time-dependent zero-dimensional code has been developed to assess the pulse length and auxiliary heating requirements of Compact Ignition Tokamak (CIT) designs. By taking a global approach to the calculation, parametric studies can be easily performed. The accuracy of the procedure is tested by comparing with the Tokamak Simulation Code which uses theory-based thermal diffusivities. A series of runs is carried out at various levels of energy confinement for each of three possible CIT configurations. It is found that for cases of interest, ignition or an energy multiplication factor Q /approxreverse arrowgt/ 7 can be attained within the first half of the planned five-second flattop with 10--40 MW of auxiliary heating. These results are supported by analytic calculations. 18 refs., 7 figs., 2 tabs

  4. Physics of compact ignition tokamak designs

    International Nuclear Information System (INIS)

    Models for predicting plasma performance in compact ignition experiments are constructed on the basis of theoretical and empirical constraints and data from tokamak experiments. Emphasis is placed on finding transport and confinement models which reproduce results of both ohmically and auxiliary heated tokamak data. Illustrations of the application of the models to compact ignition designs are given

  5. Remote maintenance concepts for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Because deuterium-tritium fuel will be used in the Compact Ignition Tokamak (CIT), remote handling technology is needed to carry out some maintenance operations on the machine. In keeping with the compact, low-cost nature of CIT, remote maintenance is provided only for systems with the highest probability of failure. Remote operations include removing, repairing (if feasible), and replacing such components as thermal protection tiles on the first wall, radio-frequency (rf) heating modules, and diagnostic modules. For maintenance inside the vacuum vessel, major pieces of equipment under development include an articulated boom manipulator with servomanipulators, an inspection manipulator, and special tooling. For maintenance outside the cryostat, remote equipment includes a bridge-mounted manipulator system, equipment for decontamination and hot cell activities, and for handling and packaging solid radioactive waste. The conceptual design phase of the CIT project is nearing completion; research and development activities in support of the project include demonstrations of remote maintenance operations on full-size partial mock-ups. 9 figs

  6. Remote maintenance of Compact Ignition Tokamak ex-vessel systems

    International Nuclear Information System (INIS)

    The use of deuterium-tritium (D-T) fuel in the Compact Ignition Tokamak (CIT) will require applying remote handling technology for ex-vessel maintenance and replacement of machine components. Highly activated and contaminated components of the fusion device's auxiliary systems, such as diagnostics and RF heating, must be replaced using remotely operated maintenance equipment in the test cell. Throughout the CIT remote maintenance (RM) studies conducted to date, computer modeling has been used extensively to investigate manipulator access in these complex, tightly packed, and cluttered surroundings. A recent refinement of computer modeling involves the use of an intelligent engineering work station for realtime interactive display of task simulations. This paper discusses the use of three-dimensional (3-D) kinematic computer models of the CIT machines that are proving to be powerful tools in our efforts to evaluate RM requirements. This presentation includes a video-taped simulation of remote replacement of a plasma viewing assembly. The simulation illustrates some of the constraints associated with typical RM activities and the ways in which computer modeling enhances the design process. 1 ref., 3 figs

  7. Maintenance concept development for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT), located at the Princeton Plasma Physics Laboratory, will be the next major experimental machine in the US Fusion Program. Its use of deuterium-tritium (D-T) fuel requires the use of remote handling technology to carry out maintenance operations on the machine. These operations consist of removing and repairing such components as diagnostic equipment modules by using remotely operated maintenance equipment. The major equipment being developed for maintenance external to the vacuum vessel includes both bridge-mounted and floor-mounted manipulator systems. Additionally, decontamination (decon) equipment, hot cell repair facilities, and equipment for handling and packaging solid radioactive waste (rad-waste) are being developed. Recent design activities have focused on establishing maintenance system interfaces with the facility design, developing manipulator system requirements, and using mock-ups to support the tokamak configuration design. 3 refs., 8 figs

  8. Maintenance features of the Compact Ignition Tokamak fusion reactor

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) is envisaged to be the next experimental machine in the US Fusion Program. Its use of deuterium/tritium fuel requires the implementation of remote handling technology for maintenance and disassembly operations. The reactor is surrounded by a close-proximity nuclear shield which is designed to permit personnel access within the test cell, one day after shutdown. With the shield in place, certain maintenance activities in the cell may be done hands-on. Maintenance on the reactor is accomplished remotely using a boom-mounted manipulator after disassembling the shield. Maintenance within the plasma chamber is accomplished with two articulated boom manipulators that are capable of operating in a vacuum environment. They are stored in a vacuum enclosure behind movable shield plugs

  9. Planning for US ion cyclotron heating research relevant to the Compact Ignition Tokamak and Alcator C-Mod

    International Nuclear Information System (INIS)

    Ion cyclotron heating (ICH) has been chosen as the primary method for providing auxiliary heating power to the plasma in the Compact Ignition Tokamak (CIT). Sustained progress in ion cyclotron range of frequencies (ICRF) heating experiments, together with supporting technology development, continues to justify selection of this technique as the preferred one for heating CIT to ignition. However, the CIT requirements are sufficiently different from existing achievements that continued experimentation and development are needed to meet the goals of the CIT experiment with a high degree of reliability. The purpose of this report is fourfold: (1) to review briefly the physics and technology research and development (R and D) needs for ICH on CIT, (2) to review the status of and planned programs for ICH on US and international machines, (3) to propose a unified ''mainline'' R and D program specifically geared to testing components for CIT, and (4) to assess the needs for experiments including C-Mod, the Tokamak Fusion Test Reactor (TFTR), and DIII-D to provide earlier information and improved probability of success for CIT ICH. 4 refs., 4 figs., 5 tabs

  10. Activation analysis of the compact ignition tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Selcow, E.C.

    1986-01-01

    The US fusion program has completed the conceptual design of a compact tokamak device that achieves ignition. The high neutron wall loadings associated with this compact deuterium-tritium-burning device indicate that radiation-related issues may be significant considerations in the overall system design. Sufficient shielding will be requied for the radiation protection of both reactor components and occupational personnel. A close-in igloo shield has been designed around the periphery of the tokamak structure to permit personnel access into the test cell after shutdown and limit the total activation of the test cell components. This paper describes the conceptual design of the igloo shield system and discusses the major neutronic concerns related to the design of the Compact Ignition Tokamak.

  11. Activation analysis of the compact ignition tokamak

    International Nuclear Information System (INIS)

    The US fusion program has completed the conceptual design of a compact tokamak device that achieves ignition. The high neutron wall loadings associated with this compact deuterium-tritium-burning device indicate that radiation-related issues may be significant considerations in the overall system design. Sufficient shielding will be requied for the radiation protection of both reactor components and occupational personnel. A close-in igloo shield has been designed around the periphery of the tokamak structure to permit personnel access into the test cell after shutdown and limit the total activation of the test cell components. This paper describes the conceptual design of the igloo shield system and discusses the major neutronic concerns related to the design of the Compact Ignition Tokamak

  12. Physics evaluation of compact tokamak ignition experiments

    International Nuclear Information System (INIS)

    At present, several approaches for compact, high-field tokamak ignition experiments are being considered. A comprehensive method for analyzing the potential physics operating regimes and plasma performance characteristics of such ignition experiments with O-D (analytic) and 1-1/2-D (WHIST) transport models is presented. The results from both calculations are in agreement and show that there are regimes in parameter space in which a class of small (R/sub o/ approx. 1-2 m), high-field (B/sub o/ approx. 8-13 T) tokamaks with aB/sub o/2/q/sub */ approx. 25 +- 5 and kappa = b/a approx. 1.6-2.0 appears ignitable for a reasonable range of transport assumptions. Considering both the density and beta limits, an evaluation of the performance is presented for various forms of chi/sub e/ and chi/sub i/, including degradation at high power and sawtooth activity. The prospects of ohmic ignition are also examined. 16 refs., 13 figs

  13. Design of an ion cyclotron resonance heating system for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The Compact Ignition Tokamak (CIT) requires 10-20 MW of ion cyclotron resonance heating (ICRH) power to raise the plasma temperature to ignition. The initial ICRH system will provide 10 MW of power to the plasma, utilizing a total of six rf power units feeding six current straps in three ports. The systems may be expanded to 20 MW with additional rf power units, antennas, and ports. Plasma heating will be achieved through coupling to the fundamental ion cyclotron resonance of a 3He minority species (also the second harmonic of tritium). The proposed antenna is a resonant double loop (RDL) structure with vacuum, shorted stubs at each end for tuning and impedance matching. The antennas are of modular, compact construction for installation and removal through the midplane port. Remote maintainability and the reactorlike operating environment have a major impact on the design of the launcher for this machine. 6 refs., 7 figs., 5 tabs

  14. Plasma engineering assessments of compact ignition experiments

    International Nuclear Information System (INIS)

    Confinement, startup sequences, and fast-alpha particle effects are assessed for a class of compact tokamak ignition experiments having high toroidal magnetic fields (8 to 12 T) and high toroidal currents (7 to 10 MA). The uncertainties in confinement scaling are spanned through examples of performance with an optimistic model based on ohmically heated plasmas and a pessimistic model that includes confinement degradation by both auxiliary and alpha heating. The roles of neoclassical resistivity enhancement and sawtooth behavior are also evaluated. Copper toroidal field coils place restrictions on pulse lengths due to resistive heating, so a simultaneous rampup of the toroidal field and plasma current is proposed as a means of compressing the startup phase and lengthening the burn phase. If the ignition window is small, fast-alpha particle physics is restricted to the high-density regime where a short slowing-down time leads to low fast-particle density and pressure contributions. Under more optimistic confinement, a larger ignition margin broadens the range of alpha particle physics that can be addressed. These issues are illustrated through examples of transport simulations for a set of machine parameters called BRAND-X, which typify the designs under study

  15. Remote maintenance design activities and research and development accomplishments for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The use of deuterium-tritium (D-T) fuel for the Compact Ignition Tokamak (CIT) requires the use of remote handling technology to carry out maintenance operations. The remote operations consist of removing and replacing such components as first wall armor protection tiles, radio-frequency (rf) heating modules, and diagnostic modules. The major pieces of equipment being developed for maintenance activities internal to the vacuum vessel include an articulated boom manipulator (ABM), an inspection manipulator, and special tooling. For activities external to the vessel, the equipment includes a bridge-mounted manipulator system, decontamination equipment, hot cell equipment, and solid radiation-waste (rad-waste) handling and packaging equipment. The CIT Project is completing the conceptual design phase; research and development (R and D) activities, which include demonstrations of remote maintenance operations on full-size partial mock-ups are under way. 5 figs

  16. The insulation irradiation test program for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The electrical insulation for the toroidal field coils of the Compact Ignition Tokamak (CIT) is expected to be exposed to radiation doses on the order of 1010 rad with ∼90% of the dose from neutrons. The coils are cooled to liquid nitrogen temperature and then heated during the pulse to a peak temperature >300 K. In a program to evaluate the effects of radiation exposure on the insulators, three types of boron-free insulation were irradiated at room temperature in the Advanced Technology Reactor (ATR) and tested at the Idaho National Engineering Laboratory. The materials were Spaulrad-S, Shikishima PG5-1, and Shikishima PG3-1. The first two use a bismaleimide resin and the third an aromatic amine hardened epoxy. Spaulrad-S is a two-dimensional (2-D) weave of S-glass, while the others are 3-D weaves of T-glass. Flexure and shear/compression samples were irradiated to approximately 5 x 109 rad and 3 x 1010 rad with 35 to 40% of the total dose from neutrons. The shear/compression samples were tested in pairs by applying an average compression of 345 MPa and then a shear load. After static tests were completed, fatigue testing was done by cycling the shear load for up to 30,000 cycles with a constant compression. The static shear strength of the samples that did not fail was then determined. Generally, shear strengths on the order of 120 MPa were measured. The behavior of the flexure and shear/compression samples was significantly different; large reductions in the flexure strength were observed, while the shear strength stayed the same or increased slightly. The 3-D weave material demonstrated higher strength and significantly less radiation damage than the 2-D material in flexure but performed nearly identically when tested with combined shear and compression. The epoxy system was much more sensitive to fatigue damage than the bismaleimide materials. 9 refs., 5 figs

  17. Compact ignition tokamak studies, ignitor concept, configuration status

    International Nuclear Information System (INIS)

    The viewgraphs present design features of the Compact Ignition Tokamak with emphasis on the magnet coils. The magnet coils are discussed with respect to preload, external torque and structural aspects

  18. Compact Ignition Tokamak Program: status of FEDC studies

    International Nuclear Information System (INIS)

    Viewgraphs on the Compact Ignition Tokamak Program comprise the report. The technical areas discussed are the mechanical configuration status, magnet analysis, stress analysis, cooling between burns, TF coil joint, and facility/device layout options

  19. Time-dependent simulations of a Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Detailed simulations of the Compact Ignition Tokamak are carried out using a 1-1/2-D transport code. The calculations include time-varying densities, fields, and plasma shape. It is shown that ignition can be achieved in this device if somewhat better than L-mode energy confinement time scaling is possible. We also conclude that the performance of such a compact, short-pulse device can depend greatly on how the plasma is evolved to its flat-top parameters. Furthermore, in cases such as the ones discussed here, where there is not a great deal of ignition margin and the electron density is held constant, ignition ends if the helium ash is not removed. In general, control of the deuterium--tritium density is equivalent to burn control. 48 refs., 15 figs

  20. Remote replacement of TF [toroidal field] and PF [poloidal field] coils for the compact ignition tokamak

    International Nuclear Information System (INIS)

    The use of deuterium-tritium fuel in the Compact Ignition Tokamak will require applying remote handling technology for ex-vessel maintenance and replacement of machine components. Highly activated and contaminated components of the fusion devices auxiliary systems, such as diagnostics and RF heating, must be replaced using remotely operated maintenance equipment in the test cell. In-vessel remote maintenance included replacement of divertor and first wall hardware, faraday shields, and for an in-vessel inspection system. Provision for remote replacement of a vacuum vessel sector, toroidal field coil or poloidal field ring coil was not included in the project baseline. As a result of recent coil failures experienced at a number of facilities, the CIT project decided to reconsider the question of remote recovery from a coil failure and, in January of 1990, initiated a coil replacement study. This study focused on the technical requirements and impact on fusion machine design associated with remote recovery from any coil failure

  1. Configuration development of a hydraulic press for preloading the toroidal field coils of the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The Fusion Engineering Design Center (FEDC) is part of a national design team that is developing the conceptual design of the Compact Ignition Tokamak (CIT). To achieve a compact device with the minimum major radius, a vertical preload system is being developed to react the vertical separating force normally carried by the inboard leg of the toroidal field (TF) coils. The preload system is in the form of a hydraulic press. Challenges in the design include the development of hydraulic and structural systems for very large force requirements, which could interface with the CIT machine, while allowing maximum access to the top, bottom, and radial periphery of the machine. Maximum access is necessary for maintenance, diagnostics, instrumentation, and control systems. Materials used in the design must function in the nuclear environment and in the presence of high magnetic fields. The structural system developed is an arrangement in which the CIT device is installed in the jaws of the press. Large built-up beams above and below the CIT span the machine and deliver the vertical force to the center cylinder formed by the inboard legs of the TF coils. During the conceptual design study, the vertical force requirement has ranged between 25,000 and 52,000 t. The access requirement on top and bottom limits the width of the spanning beams. Nonmagnetic steel materials are also required because of operation in the high magnetic fields. In the hydraulic system design for the press, several options are being explored. These range from small-diameter jacks operating at very high pressure [228 MPa (33 ksi)] to large-diameter jacks operating at pressures up to 69 MPa (10 ksi). Configurations with various locations for the hydraulic cylinders have also been explored. The nuclear environment and maintenance requirements are factors that affect cylinder location. This paper presents the configuration development of the hydraulic press used to vertically preload the CIT device

  2. Thermal and mechanical analysis of the Faraday shield for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    The antenna for the ion cyclotron resonance heating (ICRH) system of the Compact Ignition Tokamak (CIT) is protected from the plasma environment by a Faraday shield, an array of gas-cooled metallic tubes. The plasma side of the tubes is armored with graphite tiles, which can be either brazed or mechanically attached to the tube. The Faraday shield has been analyzed using finite element codes to model thermal and mechanical responses to typical CIT heating and disruption loads. Four representative materials (Inconel 718, tantalum-10 tungsten, copper alloy C17510, and molybdenum alloy TZM) and several combinations of tube and armor thicknesses were used in the thermal analysis, which revealed that maximum allowable temperatures were not exceeded for any of the four materials considered. The two-dimensional thermal stress analysis indicated Von Mises stresses greater than twice the yield stress for a tube constructed of Inconel 718 (the original design material) for the brazed-graphite design. Analysis of stresses caused by plasma disruption (/rvec J/ /times/ /rvec B/) loads eliminated the copper and molybdenum alloys as candidate tube materials. Of the four materials considered, tantalum-10 tungsten performed the best for a brazed graphite design, showing acceptable thermal stresses (69% of yield) and disruption stresses (42% of yield). A preliminary thermal analysis of the mechanically attached graphite scheme predicts minimal thermal stresses in the tube. The survivability of the graphite tubes in this scheme is yet to be analyzed. 8 refs., 19 figs., 2 tabs

  3. Physics design options for compact ignition experiments

    International Nuclear Information System (INIS)

    This paper considers the following topics: (1) physics assessments-design and engineering impact, (2) zero-dimensional confinement studies relating to physics requirements and options for ignited plasmas, classes of devices with equivalent performance, and sensitivity to variations in confinement models, and (3) one and one-half dimensional confinement studies relating to dynamic simulations, critical physics issues, startup analyses, and volt-second consumption

  4. Configuration and structural design of Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Viewgraphs are presented on the configuration and structural design of the Compact Ignition Tokamak, originally presented to the US/Japan Workshop on Next Step Machine Design. Items discussed in this presentation include: PPPL 0424 ref design; MIT LITE ref design; IGNITOR 1.01 M ref design; and IGNITOR 1.08 M press configuration

  5. CIT physics and engineering basis

    International Nuclear Information System (INIS)

    The CIT is a high-field, compact tokamak design whose objective is the study of physics issues associated with burning plasmas. The toroidal and poloidal field coils employ a copper-steel laminate, manufactured by explosive-bonding techniques, to support the forces generated by the design fields: 10 T toroidal field at the plasma center, and 21 T in the OH solenoid. A combination of internal and external PF coils provide control of the equilibrium and the ability to sweep the magnetic separatrix across the divertor plates during a pulse. At temperatures and βα levels characteristic of ITER designs, the fusion power in CIT approaches 800 MW and can be the limiting factor in the pulse length. Ignition requires that the confinement time exceed present L-mode scalings by about a factor-of-two, which is anticipated to occur as a result of the operational flexibility incorporated into the design. Conventional operating limits given by right-angle β left-angle 20 e and qΨ ≤ 3.2 have been chosen and, in the case of MHD limits, have been justified by ideal stability analysis. The power required for CIT ignition ranges from 10 MW to 40 MW or more, depending on confinement assumptions, and either ICRF or ECRF heating, or both, will be used. 12 refs., 6 figs

  6. Compact Ignition Tokamak Program: R and D needs

    International Nuclear Information System (INIS)

    This report on the Compact Ignition Tokamak Program supplies information concerning: segmented vacuum vessel joint development; first wall tile attachments; first wall/tile development - composite materials; vacuum leak detection; high frequency rf sources; Faraday shield development; design and testing of rf launchers for high power, ling pulse operation; radiation hardened, low loss, dielectric windows for rf, IR, visible, UV and X-rays, mirrors for changing direction and focusing IR, visible and UV radiation; radiation resistant optical dielectric wave guides; radiation resistant HV insulation for diagnostic magnetic pickup coils; compact radiation and/or magnetic shielding for in-vault diagnostics that need some attenuation to reduce S/N ratio; radiation hardened line-of-sight sensors such as bolometers, UV and soft X-ray detectors, neutral particle analyzers, torus pressure gauges; special maintenance fixtures and tools; material properties - design data base - all materials; and insulation - electrical/thermal and mechanical properties

  7. Computer support for the CIT physics

    International Nuclear Information System (INIS)

    The authors describe how the conceptual design for the physics support segment of the Compact Ignition Tokamak (CIT) computer system is being based on a network of man-machine workstations, data acquisition/control processors, database servers, nodes and gateways. The Diagnostic Support Subsystem will consist of networked workstations and control/data aquisition processors with interfaces to CAMAC, PLC; and probably more modern busses for data-intensive front-end processing systems. Distributed database support for calibration, configuration, raw and results data will be provided. Extensions of existing fusion device functionalities and performance requirements, based on interaction with the CIT diagnostics engineering team and projections and criteria for design selection. Interfaces to the real-time plasma control, hardwired interlock, graphics/hardcopy, and timing systems are included

  8. Insulation irradiation test programme for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    In a programme to evaluate the effects of radiation exposure on the electrical insulation for the toroidal field coils of the Compact Ignition Tokamak, three types of boron-free insulation were irradiated at room temperature in the Advanced Technology Reactor (ATR) and tested at the Idaho National Engineering Laboratory. The materials were Spaulrad-S, Shikishima PG5-1 and Shikishima PG3-1. The first two use a bismaleimide resin and the third an aromatic amine hardened epoxy. Spaulrad-S is a two-dimensional (2-D) weave of S-glass, while the others are 3-D weaves of T-glass. Flexure and shear/compression samples were irradiated to ≅ 5 x 109 and 3 x 1010 rad with 35-40% of the total dose from neutrons. The shear/compression samples were tested in pairs by applying an average compression of 345 MPa and then a shear load. After static tests were completed, fatigue testing was performed by cycling the shear load for up to 30000 cycles with a constant compression. The static shear strength of the samples that did not fail was then determined. Generally, shear strengths of the order of 120 MPa were measured. The behaviour of the flexure and shear/compression samples was significantly different; large reductions in the flexure strength were observed, while the shear strength stayed the same or increased slightly. The 3-D weave material demonstrated higher strength and significantly less radiation damage than the 2-D material in flexure but performed almost identically when tested with combined shear and compression. The epoxy system was much more sensitive to fatigue damage than the bismaleimide materials. No swelling was measured; however, the epoxy samples did twist slightly. (author)

  9. Plans for the CIT Instrumentation and Control System

    International Nuclear Information System (INIS)

    Extensive experience with previous fusion experiments (TFTR, MFTF-B and others) is driving the design of the Instrumentation and Control System (I ampersand C) for the Compact Ignition Tokamak (CIT) to be built at Princeton. The new design will reuse much equipment from TFTR and will be subdivided into six major parts: machine control, machine data acquisition, plasma diagnostic instrument control and instrument data acquisition, the database, shot sequencing and safety interlocks. In a major departure from previous fusion experiment control systems, the CIT machine control system will be a commercial process control system. Since the machine control system will be purchased as a completely functional product, the authors will be able to concentrate development manpower in plasma diagnostic instrument control, data acquisition, data processing and analysis, and database systems. They will discuss the issues driving the design, give a design overview and state the requirements upon any prospective commercial process control system

  10. Interim report on the assessment of engineering issues for compact high-field ignition devices

    International Nuclear Information System (INIS)

    The engineering issues addressed at the workshop included the overall configuration, layout, and assembly; limiter and first-wall energy removal; magnet system structure design; fabricability; repairability; and costs. In performing the assessment, the primary features and characteristics of each concept under study were reviewed as representative of this class of ignition device. The emphasis was to understand the key engineering areas of concern for this class of device and deliberately not attempt to define an optimum design or to choose a best approach. The assessment concluded that compact ignition tokamaks, as represented by the three concepts under study, are feasible. A number of critical engineering issues were identified, and all appear to have tractable solutions. The engineering issues appear quite challenging, and to obtain increased confidence in the apparent design solutions requires completion of the next level of design detail, complemented by appropriate development programs and testing

  11. Elastic-plastic analysis of the toroidal field coil inner leg of the compact ignition tokamak

    International Nuclear Information System (INIS)

    Elastic-plastic analyses were made for the inner leg of the Compact Ignition Tokamak toroidal field (TF) coil, which is made of copper-Inconel composite material. From the result of the elastic-plastic analysis, the effective Young's moduli of the inner leg were determined by the analytical equations. These Young's moduli are useful for the three-dimensional, elastic, overall TF coil analysis. Comparison among the results of the baseline design (R = 1.324 m), the bucked pressless design, the 1.527-m major radius design, and the 1.6-m major radius design was also made, based on the elastic-plastic TF coil inner leg analyses

  12. Modeling of compact loop antennas

    Science.gov (United States)

    Baity, F. W.

    1987-09-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively tuned resonant double loop (RDL) antennas, the model treats sub-tuned RDL antennas. Calculations using the model have been compared with measurements on full-scale mock-ups of RDL antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and the Compact Ignition Tokamak (CIT).

  13. The Compact Ignition Tokamak and electron cyclotron heating: Description of need; assessment of prospects

    International Nuclear Information System (INIS)

    The CIT will benefit from auxiliary heating of 10 to 40 MW. The schedules of both the CIT construction project and the operating plan contain adequate time to develop and implement ECH systems based on the gyrotron and the induction free electron laser (IFEL). Each approach has advantages and is the object of R and D at the level of many millions of dollars per year. While the gyrotron is further advanced in terms of power and pulse length achieved, rapid progress is scheduled for the IFEL, including experiments on tokamaks. Plans of CIT, gyrotron, and IFEL make 1992 an appropriate time frame to commit to one or both systems. 12 refs., 8 figs., 2 tabs

  14. Neutron production rates during four transitions from DT to D3He ignited plasmas in a compact tokamak

    International Nuclear Information System (INIS)

    Neutron production rates (due to DT, DD, TT and T3He reactions) and D3He reaction rate during four transitions from DT to D3He ignited plasmas (characterized by different evolutions of ion densities and temperature) in a compact tokamak have been calculated. In this paper, for each transition, the results are reported in graphical form (one curve for each reaction) and shortly discussed. The main feature is the predominance of 14 MeV DT-neutrons, whose production rate does not appear to be negligible. It is therefore concluded that while acceptable in experiments of D3He ignition, tritium-assistance may not be suitable for routine startup of D3He fusion power plants, in which plasma temperature will hae to be raised to ignition level probably by other means. Mention to a program aimed at measuring cross sections of some neutron-lean fusion reactions is also made

  15. Two-dimensional discrete ordinates calculations of prompt radiation responses in the 1.75 m CIT

    International Nuclear Information System (INIS)

    Two-dimensional calculations of the prompt radiation responses in the 1.75 m Compact Ignition Tokamak (CIT) have been carried out with a discrete ordinates model using the DOT 5.1 code. Of primary interest in the calculations was the nuclear heating rates in major tokamak structures such as the first wall, vacuum vessel and TF coils, which are required for the thermal and structural analyses. Comparisons were made with the results obtained with one-dimensional discrete ordinates models. Efforts were made to arrive at a simple algorithm that will provide the approximate two-dimensional distributions without the need to run a multi-dimensional model

  16. Physics overview of CIT

    International Nuclear Information System (INIS)

    The physics parameters and operational modes of CIT are set by a combination of detailed analysis and extrapolation from the existing tokamak data base. Some of the innovations being incorporated into the CIT design include sweeping of the separatrix across the divertor plates to spread the heat load, two-timescale radial position control utilizing both internal and external PF coils, optimized plasma shape control using a digital controller, and fusion burn control by modulating the heating source. Models of disrupting plasmas have been developed to compute structural loads. These include the effects of induced currents in the plasma halo region in which field lines intersect the vessel walls. 12 refs., 3 figs

  17. Preliminary power supply design for the TF coil system of CIT

    International Nuclear Information System (INIS)

    Initial operation of the Compact Ignition Tokamak (CIT) is planned with a Toroidal Field (TF) of 8 Tesla and a flat top duration of 5 seconds. Ultimately, operation will be extended beyond 8 Tesla. The power supply to be used for the initial phase of operation has been modeled using the parameters of the thyristor rectifier power supplies which are now in service for the Tokamak Fusion Test Reactor (TFTR). A subset of these existing units, or perhaps new units with similar ratings, are envisioned to be connected to the existing 138kV transmission line serving PPPL so as to take advantage of this power source for CIT. For the extended operation phase the equipment used for the initial phase of TF operation will be augmented with new equipment to permit operation up to 11 Tesla. This paper describes the preliminary design for the 8 Tesla power supply and presents results from simulation studies. In addition, issues concerning transient behavior and fault modes are discussed. 4 refs., 12 figs

  18. Evaluation of weldments in Type 21-6-9 stainless steel for Compact Ignition Tokamak structural applications: Phase 1

    International Nuclear Information System (INIS)

    Primary design considerations for the Compact Ignition Tokamak toroidal field-coil cases are yield strength and toughness in the temperature range from 77 to 300 K. Type 21-6-9 stainless steel, also still known by its original Armco Steel Company trade name Nitronic 40, is the proposed alloy for this application. It has high yield strength and usually adequate base metal toughness, but weldments in thick sections have not been adequately characterized in terms of mechanical properties or hot-cracking propensity. In this study, weldability of the alloy in heavy sections and the mechanical properties of the resultant welds were investigated including tensile yield strength and Charpy V-notch toughness at 77 K and room temperature. Weldments were made in four different base metals using seven different filler metals. None of the weldments showed any indication of hot-cracking problems. All base metals, including weldment heat-affected zones, were found to have adequate strength and impact toughness at both test temperatures. Weld metals, on the other hand, except ERNiCr-3 and ENiCrFe-3 had impact toughnesses of less than 67 J at 77 K. Inconel 82 had an average weld metal impact toughness of over 135 J at 77 K, and although its strength at 77 K is less than that of type 21-6-9 base metal, at this point it is considered to be the first-choice filler metal. Phase 2 of this program will concentrate on composition refinement and process/procedure optimization for the generic ERNiCr-3 composition and will generate a design data base for base and weld metal, including tensile, fracture toughness, and crack growth rate data

  19. TIBER (Tokamak Ignition/Burn Experimental Reactor) II as a precursor to an international thermonuclear experimental reactor

    International Nuclear Information System (INIS)

    The Tokamak Ignition/Burn Experimental Reactor (TIBER) was pursued in the US as one option for an International Thermonuclear Experimental Reactor (ITER). This concept evolved from earlier work on the Tokamak Fusion Core Experiment (TFCX) to develop a small, ignited tokamak. While the copper-coil versions of TFCX became the short-pulsed, 1.23-m radius, Compact Ignition Tokamak (CIT), the superconducting TIBER with long pulse or steady state and a 2.6-m radius was considered for international collaboration. Recently the design was updated to TIBER II, to accommodate more conservative confinement scaling, double-poloidal divertors for impurity control, steady-state current drive, and nuclear testing. 18 refs., 1 fig

  20. Power radiated from ITER and CIT by impurities

    International Nuclear Information System (INIS)

    The MIST code has been used to model impurity radiation from the edge and core plasmas in ITER and CIT. A broad range of parameters have been varied, including Zeff, impurity species, impurity transport coefficients, and plasma temperature and density profiles, especially at the edge. For a set of these parameters representative of the baseline ITER ignition scenario, it is seen that impurity radiation, which is produced in roughly equal amounts by the edge and core regions, can make a major improvement in divertor operation without compromising core energy confinement. Scalings of impurity radiation with atomic number and machine size are also discussed. 22 refs., 16 figs

  1. Metabolism and autoradiographic evaluation of [{sup 18}F]FE-CIT: a Comparison with [{sup 123}I]{beta}-CIT and [{sup 123}I]FP-CIT

    Energy Technology Data Exchange (ETDEWEB)

    Ettlinger, Dagmar E. [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Haeusler, Daniela; Wadsak, Wolfgang [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Girschele, Friedrich; Sindelar, Karoline M. [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Mien, Leonhard-Key [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Ungersboeck, Johanna [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Viernstein, Helmut; Kletter, Kurt; Dudczak, Robert [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Mitterhauser, Markus [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria)], E-mail: markus.mitterhauser@meduniwien.ac.at

    2008-05-15

    Purpose: Since the late 1980s, cocaine analogues based on the phenyltropane structure, such as [{sup 11}C]CFT and [{sup 123}I]{beta}-CIT have been used for the imaging of the dopamine transporter. FE-CIT (fluoropropyl ester) and FP-CIT (N-fluoropropyl derivative) are further analogues. The aim of this study was to (1) evaluate and compare the metabolic stability of {beta}-CIT, FP-CIT and FE-CIT against carboxyl esterases and (2) evaluate selectivity of [{sup 18}F]FE-CIT compared to [{sup 123}I]{beta}-CIT and [{sup 123}I]FP-CIT using autoradiography. Methods: In vitro enzymatic hydrolysis assays were performed using different concentrations of {beta}-CIT, FE-CIT and FP-CIT with constant concentrations of carboxyl esterase. Autoradiography was performed on coronal 20-{mu}m rat brain sections incubated with different radioactivity concentrations of [{sup 123}I]{beta}-CIT, [{sup 123}I]FP-CIT or [{sup 18}F]FE-CIT and, additionally, with 3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl)-benzonitrile [serotonin transporter (SERT)] and nisoxetine [norepinephrine transporter (NET)] for blocking experiments. Results: In vitro assays showed Michaelis-Menten constants of 175 {mu}mol ({beta}-CIT), 183 {mu}mol (FE-CIT) and 521 {mu}mol (FP-CIT). Limiting velocities were 0.1005 {mu}mol/min ({beta}-CIT), 0.1418 {mu}mol/min (FE-CIT) and 0.1308 {mu}mol/min (FP-CIT). This indicates a significantly increased stability of FP-CIT, whereas carboxyl esterase stability of {beta}-CIT and FE-CIT showed no significant difference. Autoradiographic analyses revealed a good correlation between dopamine transporter (DAT)-rich regions and the uptake pattern of FE-CIT. Blocking experiments showed a higher DAT selectivity for [{sup 18}F]FE-CIT than for the other two tracers. Conclusion: We found that (1) the metabolic stability of FE-CIT was comparable to that of {beta}-CIT, whereas FP-CIT showed higher resistance to enzymatic hydrolysis; and (2) the overall uptake pattern of [{sup 18}F]FE-CIT on

  2. An interim report on the materials and selection criteria analysis for the Compact Ignition Tokamak Toroidal Field Coil Turn-to-Turn Insulation System

    International Nuclear Information System (INIS)

    Design criteria for the Compact Ignition Tokamak, Toroidal-Field (TF) Coil, Turn-to-Turn Insulation System require an insulation sheet and bonding system that will survive cryogenic cycling in a radiation environment and maintain structural integrity during exposure to the significant compressive and shear loads associated with each operating cycle. For thermosetting resin systems, a complex interactive dependency exists between optimum peak value, in-service property performance capabilities of candidate generic materials; key handling and processing parameters required to achieve their optimum in-service property performance as an insulation system; and suitability of their handling and processing parameters as a function of design configuration and assembly methodology. This dependency is assessed in a weighted study matrix in which two principal programmatic approaches for the development of the TF Coil Subassembly Insulation System have been identified. From this matrix study, two viable approaches to the fabrication of the insulation sheet were identified: use of a press-formed sheet bonded in place with epoxy for mechanical bonding and tolerance take-up and formation of the insulation sheet by placement of dry cloth and subsequent vacuum pressure impregnation. Laboratory testing was conducted to screen a number of combinations of resins and hardeners on a generic basis. These combinations were chosen for their performance in similar applications. Specimens were tested to screen viscosity, thermal-shock tolerance, and cryogenic tolerance. Cryogenic shock and cryogenic temperature proved to be extremely lethal to many combinations of resin, hardener, and cure. Two combinations survived: a heavily flexibilized bisphenol A resin with a flexibilized amine hardener and a bisphenol A resin with cycloaliphatic amine hardener. 7 refs., 12 figs., 6 tabs

  3. Compact ignition tokamak design studies

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    Viewgraphs are given on the following objectives of the design study: (1) develop core module concept, (2) develop a method to apply preload, (3) perform sufficient analysis to demonstrate total concept is structurally sound, (4) develop component fit-up and assembly scheme, and (5) minimize size and cost. (MOW)

  4. Systems studies of high-field tokamak ignition experiments

    International Nuclear Information System (INIS)

    A study of the interaction between the physics of ignition and the engineering constraints in the design of compact, high-field tokamak ignition demonstration devices is presented. The studies investigate the effects the various electron and ion thermal diffusivities, which result from the many tokamak scaling laws, have on the design parameters of an ignition device and show the feasibility of building and igniting a compact tokamak (R<1m). The relevant machine technology is discussed

  5. A technique for extending by ∼103 the dynamic range of compact proton spectrometers for diagnosing ICF implosions on the National Ignition Facility and OMEGA

    International Nuclear Information System (INIS)

    Wedge Range Filter (WRF) proton spectrometers are routinely used on OMEGA and the NIF for diagnosing ρR and ρR asymmetries in direct- and indirect-drive implosions of D3He-, D2-, and DT-gas-filled capsules. By measuring the optical opacity distribution in CR-39 due to proton tracks in high-yield applications, as opposed to counting individual tracks, WRF dynamic range can be extended by 102 for obtaining the spectral shape, and by 103 for mean energy (ρR) measurement, corresponding to proton fluences of 108 and 109 cm−2, respectively. Using this new technique, ρR asymmetries can be measured during both shock and compression burn (proton yield ∼108 and ∼1012, respectively) in 2-shock National Ignition Facility implosions with the standard WRF accuracy of ±∼10 mg/cm2

  6. A technique for extending by ∼10{sup 3} the dynamic range of compact proton spectrometers for diagnosing ICF implosions on the National Ignition Facility and OMEGA

    Energy Technology Data Exchange (ETDEWEB)

    Sio, H., E-mail: hsio@mit.edu; Séguin, F. H.; Frenje, J. A.; Gatu Johnson, M.; Zylstra, A. B.; Rinderknecht, H. G.; Rosenberg, M. J.; Li, C. K.; Petrasso, R. D. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)

    2014-11-15

    Wedge Range Filter (WRF) proton spectrometers are routinely used on OMEGA and the NIF for diagnosing ρR and ρR asymmetries in direct- and indirect-drive implosions of D{sup 3}He-, D{sub 2}-, and DT-gas-filled capsules. By measuring the optical opacity distribution in CR-39 due to proton tracks in high-yield applications, as opposed to counting individual tracks, WRF dynamic range can be extended by 10{sup 2} for obtaining the spectral shape, and by 10{sup 3} for mean energy (ρR) measurement, corresponding to proton fluences of 10{sup 8} and 10{sup 9} cm{sup −2}, respectively. Using this new technique, ρR asymmetries can be measured during both shock and compression burn (proton yield ∼10{sup 8} and ∼10{sup 12}, respectively) in 2-shock National Ignition Facility implosions with the standard WRF accuracy of ±∼10 mg/cm{sup 2}.

  7. Ignitor with stable low-energy thermite igniting system

    Science.gov (United States)

    Kelly, Michael D.; Munger, Alan C.

    1991-02-05

    A stable compact low-energy igniting system in an ignitor utilizes two components, an initiating charge and an output charge. The initiating charge is a thermite in ultra-fine powder form compacted to 50-70% of theoretical maximum density and disposed in a cavity of a header of the ignitor adjacent to an electrical ignition device, or bridgewire, mounted in the header cavity. The initiating charge is ignitable by operation of the ignition device in a hot-wire mode. The output charge is a thermite in high-density consoladated form compacted to 90-99% of theoretical maximum density and disposed adjacent to the initiating charge on an opposite end thereof from the electrical ignition device and ignitable by the initiating charge. A sleeve is provided for mounting the output charge to the ignitor header with the initiating charge confined therebetween in the cavity.

  8. Applications of CIT to Teaching Unreal Conditional Sentences

    Institute of Scientific and Technical Information of China (English)

    沈莉

    2009-01-01

    At present, metaphor research has shown special concerns for development of metaphorical competence in the process of second language acquisition. With the development of Coficeptual Metaphor Theory (CMT)and Conceptual Integration Theory (CIT),some studies are being taken to justify the significance of these two theories in L2 teaching. However, little work has been done to the study and connection between CIT and L2 teaching. This paper tends to prove CIT to be practicable and efficient in L2 teaching, especially in teaching unreal conditional sentences.

  9. Convective Induced Turbulence (CIT) Detection via Total Lightning Sensing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We proposes to build a prototype Convective-Induced Turbulence (CIT) hazard detection system based on total lightning sensing as an indicator of the location and...

  10. Physical Improvements in Exciter/Igniter Units Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase 2 project consists of the physical integration of our Phase 1 small, compact exciter with a "flight like" igniter or spark plug capable of...

  11. The astrosphere of the Asymptotic Giant Branch star CIT 6

    CERN Document Server

    Sahai, Raghvendra

    2014-01-01

    We have discovered two extended half-ring structures in a far-ultraviolet image taken with the GALEX satellite of the well-known mass-losing carbon star CIT 6 (RW LMi). The northern (southern) ring is brighter (fainter) with a diameter of about 15 arcmin (18 arcmin). These structures most likely represent the astrosphere resulting from the shock interaction of CIT 6's molecular wind with the Warm Interstellar Medium, as it moves through the latter. These data provide a direct estimate of the size of CIT 6's circumstellar envelope that is a factor ~20 larger than previous estimates based on CO millimeter-wave line data. We find that CIT 6 has been undergoing heavy mass-loss for at least 93,000 yr and the total envelope mass is 0.29 Msun or larger, assuming a constant mass-loss rate of 3.2 x 10^(-6) Msun/yr. Assuming that the shock front has reached a steady-state and CIT 6's motion relative to the ISM is in the sky-plane, we measure the termination-shock standoff distance directly from the image and find that ...

  12. Alternative labelling of the cocaine analogue isomers α-CIT and β-CIT by direct iodination with no-carrier-added Na125I

    International Nuclear Information System (INIS)

    An alternative labelling of the cocaine analogue isomers α-CIT and β-CIT with no-carrier-added 125I by direct iodination of 2α- and 2β-carbomethoxy-3β-phenyltropane with Na125I/sulfuric acid/nitric acid/acetic acid and peracetic acid under different reaction conditions, is described. The maximum radiolabelling yield obtained with the two isomers was 48% for [125I]α-CIT and 28% for [125I]β-CIT. (author)

  13. Jet pellet ablation studies and projections for CIT and ITER

    International Nuclear Information System (INIS)

    Pellet penetration in JET is analyzed and compared with predictions of the neutral gas and plasma shielding (NGPS) model for pellet ablation. The model is then used to evaluate pellet penetration in CIT and ITER. A simplified scaling law is derived for pellet penetration when the shielding is dominated by the cold ablatant plasma. Comparison with a similarly derived scaling law for the original neutral gas shielding (NGS) model shows that pellet size and plasma electron temperature dependences are similar, but velocity scaling is reduced or completely absent in the NGPS model. We show that projected penetration for higher-velocity pellets may be erroneous with the NGPS model. If the neutral gas shield dominates, as it probably does if the neutral gas shield is elongated along the magnetic field, pellet penetration in JET, CIT, and ITER can be significantly enhanced with higher pellet velocities. 13 refs., 2 figs., 2 tabs

  14. Transmembrane segment (TMS) VIII of the Na+/citrate transporter CitS requires downstream TMS IX for insertion in the Escherichia coli membrane

    NARCIS (Netherlands)

    van Geest, M; Lolkema, JS

    1999-01-01

    The amino acid sequence of the sodium ion-dependent citrate transporter CitS of IL pneumoniae contains 12 hydrophobic stretches that could form membrane-spanning segments. A previous analysis of the membrane topology in Escherichia coli using the PhoA gene fusion technique indicated that only nine o

  15. The Citrus transcription factor, CitERF13, regulates citric acid accumulation via a protein-protein interaction with the vacuolar proton pump, CitVHA-c4.

    Science.gov (United States)

    Li, Shao-jia; Yin, Xue-ren; Xie, Xiu-lan; Allan, Andrew C; Ge, Hang; Shen, Shu-ling; Chen, Kun-song

    2016-01-01

    Organic acids are essential to fruit flavor. The vacuolar H(+) transporting adenosine triphosphatase (V-ATPase) plays an important role in organic acid transport and accumulation. However, less is known of V-ATPase interacting proteins and their relationship with organic acid accumulation. The relationship between V-ATPase and citric acid was investigated, using the citrus tangerine varieties 'Ordinary Ponkan (OPK)' and an early maturing mutant 'Zaoshu Ponkan (ZPK)'. Five V-ATPase genes (CitVHA) were predicted as important to citric acid accumulation. Among the genes, CitVHA-c4 was observed, using a yeast two-hybrid screen, to interact at the protein level with an ethylene response factor, CitERF13. This was verified using bimolecular fluorescence complementation assays. A similar interaction was also observed between Arabidopsis AtERF017 (a CitERF13 homolog) and AtVHA-c4 (a CitVHA-c4 homolog). A synergistic effect on citric acid levels was observed between V-ATPase proteins and interacting ERFs when analyzed using transient over-expression in tobacco and Arabidopsis mutants. Furthermore, the transcript abundance of CitERF13 was concomitant with CitVHA-c4. CitERF13 or AtERF017 over-expression leads to significant citric acid accumulation. This accumulation was abolished in an AtVHA-c4 mutant background. ERF-VHA interactions appear to be involved in citric acid accumulation, which was observed in both citrus and Arabidopsis. PMID:26837571

  16. Implosion hydrodynamics of fast ignition targets

    International Nuclear Information System (INIS)

    The fast ignition (FI) concept requires the generation of a compact, dense, pure fuel mass accessible to an external ignition source. The current base line FI target is a shell fitted with a reentrant cone extending to near its center. Conventional direct- or indirect-drive collapses the shell near the tip of the cone and then an ultraintense laser pulse focused to the inside cone tip generates high-energy electrons to ignite the dense fuel. A theoretical and experimental investigation was undertaken of the collapse of such targets, validating modeling, and exploring the trade-offs available, in such an asymmetric geometry, to optimize compaction of the fuel and maintain the integrity of the cone. The collapse is complex. Away from the cone, the shell collapses much as does a conventional implosion, generating a hot, low-density inner core. But because of the open side, hot plasma exhausts out toward the tip of the cone. This hot plasma is advantageous for implosion diagnostics; it can provide protons for angular dependent measurements of the shell wall, neutrons for temperature measurements, and self-emission for contamination measurements. But for FI it is a liability; the hot, low-density inner core impedes the compaction of the cold fuel, lowering the implosion/burn efficiency and the gain. Approaches to optimizing this shell design are discussed

  17. C-ITS as Multidisciplinary Area with High Demand on Telecommunications Solutions

    Directory of Open Access Journals (Sweden)

    Tomas Zelinka

    2014-08-01

    Full Text Available Cooperative Intelligent Transport Systems (C-ITS are concentrated on transportation systems with goal to improve usability, efficiency and safety of the existing as well as newly constructed transportation infrastructure. These concepts are associated with high society expectations that C-ITS will principally participate in resolving of continuously growing transportation challenges. C-ITS represents typical multidisciplinary area where effective cooperation of wide range of different disciplines is the key condition of the success. Possible approach to treatment of requirements on telecommunication services in C-ITS applications is presented.

  18. Reaching ignition in the tokamak

    International Nuclear Information System (INIS)

    This review covers the following areas: (1) the physics of burning plasmas, (2) plasma physics requirements for reaching ignition, (3) design studies for ignition devices, and (4) prospects for an ignition project

  19. Compact torsatron reactors

    International Nuclear Information System (INIS)

    Low-aspect-ratio torsatron configurations could lead to compact stellarator reactors with R0 = 8--11m, roughly one-half to one-third the size of more conventional stellarator reactor designs. Minimum-size torsatron reactors are found using various assumptions. Their size is relatively insensitive to the choice of the conductor parameters and depends mostly on geometrical constraints. The smallest size is obtained by eliminating the tritium breeding blanket under the helical winding on the inboard side and by reducing the radial depth of the superconducting coil. Engineering design issues and reactor performance are examined for three examples to illustrate the feasibility of this approach for compact reactors and for a medium-size (R0 ≅ 4 m,/bar a/ /approx lt/ 1 m) copper-coil ignition experiment. 26 refs., 11 figs., 7 tabs

  20. Low profile thermite igniter

    Science.gov (United States)

    Halcomb, Danny L.; Mohler, Jonathan H.

    1991-03-05

    A thermite igniter/heat source comprising a housing, high-density thermite, and low-density thermite. The housing has a relatively low profile and can focus energy by means of a torch-like ejection of hot reaction products and is externally ignitable.

  1. Sherlock Holmes : science et récit : "histoire"

    OpenAIRE

    Jaussaud, Philippe

    2013-01-01

    les enquêtes de Sherlock Holmes ont été publiées entre 1887 et 1927 - principalement dans le Strand Magazine - par Arthur Conan Doyle (1859-1930). Dans la perspective d'une exploitation didactique de ces textes, la question de recherche posée est la suivante : " quelle est la place occupée par les disciplines scientifiques dans les soixante récits du " canon " holmésien ? ", sachant que celui-ci traverse, dans sa chronologie, les époques victorienne et edwardienne. De très nombreuses discipli...

  2. Ignition tuning for the National Ignition Campaign

    Directory of Open Access Journals (Sweden)

    Landen O.

    2013-11-01

    Full Text Available The overall goal of the indirect-drive inertial confinement fusion [1] tuning campaigns [2] is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics [3] used in our radiation-hydrodynamic computational models, and by checking for and resolving unexpected shot-to-shot variability in performance [4]. This has been started successfully using a variety of surrogate capsules that set key laser, hohlraum and capsule parameters to maximize ignition capsule implosion velocity, while minimizing fuel adiabat, core shape asymmetry and ablator-fuel mix.

  3. A multi-wavelength study of the oxygen-rich AGB star CIT 3 Bispectrum speckle interferometry and dust-shell modelling

    CERN Document Server

    Hofmann, Karl Heinrich; Blöcker, T; Weigelt, G

    2001-01-01

    (abridged) CIT 3 is an oxygen-rich long-period variable evolving along the AGB and one of the most extreme infrared AGB objects. We present the first bispectrum speckle-interferometry observations of CIT 3 in the J-, H-, and K'-band (resolution: 48mas, 56mas, and 73mas). The interferograms were obtained with the Russian SAO 6m telescope. While CIT 3 appears almost spherically symmetric in the H- and K'-band, it is clearly elongated in the J-band along a symmetry axis of position angle -28 degr. Two structures can be identified: a compact elliptical core (eccentricity ~0.8) and a fainter north-western fan-like structure (full opening angle ~40 degr). Extensive radiative transfer calculations have been carried out and confronted with the spectral energy distribution, our 1.24, 1.65 and 2.12 micron visibility functions, and 11micron ISI interferometry. The best model refers to a cool central star (Teff=2250K) surrounded by an optically thick dust shell (tau_V = 30). The central-star diameter is 10.9mas and the i...

  4. Modeling of compact loop antennas

    International Nuclear Information System (INIS)

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak

  5. Modeling of compact loop antennas

    International Nuclear Information System (INIS)

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively tuned resonant double loop (RDL) antennas, the model treats sub-tuned RDL antennas. Calculations using the model have been compared with measurements on full-scale mock-ups of RDL antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and the Compact Ignition Tokamak

  6. SPECT quantification of 123I - and - CIT in Parkinsonism

    International Nuclear Information System (INIS)

    Full text: Evaluation of presynaptic dopaminergic function using 2B-carboxymethoxy-3B-(4-[123I] iodophenyl) tropane (123I-and-CIT) SPECT has employed subjective or semi-quantitative methods. Our hypothesis is that disease classification in Parkinsonism may be improved by partial volume correction and co-registration with MRI. We studied seven patients (pts) with IPD (four men, three women, mean age=54.5+/-10.9 yrs; Hoehn and Yahr stage range 1-3; Schwab and England scale range: 30-100 [mean=67.1+/-26.9]) and two controls with 123I--CIT using 110-150 MBq and a dual-head camera equipped with fan-beam collimation. SPECT was registered to MRI and then aligned to a reference template. Specific to non-specific dopaminergic binding (UR) was calculated for the putamen and caudate nucleus, as well as the fractional volume (FV; fraction of the Structure affected) and residual uptake ratio (RUR; count density in area/remnant apparently unaffected by disease). Parameters that were statistically significant were the putamen (p; but not caudate) UR, FV and RUR. We conclude that: (a) it is possible to distinguish dopaminergic activity within the putamen from caudate using MRI image co-registration and (b) parameters other than UR may discriminate IPD from normal subjects and other entities. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  7. To the scenario choosing of plasma density limit reaching in the CIT tokamak

    International Nuclear Information System (INIS)

    Results of numerical simulation of reaching of maximum permissible plasma density in CIT tokamak are given. Scenario optimization principles that are not connected with specific plasma confinement model are formulated; it is important if real conditions (heat transfer, diffusion, convection etc) in CIT tokamak plasma would be different from one that are considered in the simulation. 10 refs.; 3 figs

  8. Transport simulations of ohmic ignition experiment: IGNITEX

    International Nuclear Information System (INIS)

    The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large (≤2), and anomalous radiation and alpha losses and/or other enhanced transport losses (/eta//sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters (aB02/q* /approximately/ IB0, etc.) are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

  9. COMPACT OPERATORS

    Directory of Open Access Journals (Sweden)

    Charles Swartz

    2009-12-01

    Full Text Available We give a characterization in terms of the transpose operator for a continuous linear operator between locally convex spaces to map bounded sets into relatively weakly compact [relatively compact, precompact] sets. Our results give a known characterization for compact operators between Banach spaces.

  10. Acoustic Igniter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An acoustic igniter eliminates the need to use electrical energy to drive spark systems to initiate combustion in liquid-propellant rockets. It does not involve the...

  11. Synthesis of β-CIT、β-FP-CIT and Its Precursor nor-β-CIT%β-CIT、β-FP-CIT及其前体nor-β-CIT的合成

    Institute of Scientific and Technical Information of China (English)

    唐刚华; 唐小兰

    2001-01-01

    2-β-甲酯基-3-β-(4-碘苯基)降托烷(nor-β-CIT)是多巴胺转运蛋白正电子显像剂[11C]-2-β-甲酯基-3-β-(4-碘苯基)托品烷([11C]-β-CIT)和[18F]-N-3-氟丙基-2-β-甲酯基-3-β-(4-碘苯基)降托烷([18F]-β-FP-CIT)的前体。本实验以可卡因为原料,经水解、脱水、酯化、格氏化、碘化、脱甲基等步骤合成了nor-β-CIT,总产率为12.9%,并以nor-β-CIT为原料合成了β-CIT和β-FP-CIT,为进一步放射化学合成[11C]-β-CIT和[18F]-β-FP-CIT提供了可靠的技术路线。%[11C]-2-β-Carbomethoxy-3-β-(4-iodophenyl)tropane([11C]-β-CIT)and [18F]-N-3-fluoropropyl-2-β-carbomethoxy-3-β-(4-iodophenyl)nortropane([18F]-β-FP-CIT)are the positron imaging agents as dopamine transporters,whose precursor is 2-β-carbomethoxy-3-β-(4-iodophenyl)nortropane(nor-β-CIT).The nor-β-CIT was synthesized from the cocaine as the starting material,which was based on hydrolysis,dehydration,esterification,Grignard reaction,iodination and demethylation,the total yield from the cocaine was 12.9%.The β-CIT was synthesized from the nor-β-CIT reaction with CH3I,and the β-FP-CIT synthesized from the nor-β-CIT reaction with FCH2CH2CH2Br.The study provided a practical method for radiochemical synthesis of [11C]-β-CIT and [18F]-β-FP-CIT.

  12. Fusion ignition via a magnetically-assisted fast ignition approach

    CERN Document Server

    Wang, W -M; Sheng, Z -M; Li, Y T; Zhang, J

    2016-01-01

    Significant progress has been made towards laser-driven fusion ignition via different schemes, including direct and indirect central ignition, fast ignition, shock ignition, and impact ignition schemes. However, to reach ignition conditions, there are still various technical and physical challenges to be solved for all these schemes. Here, our multi-dimensional integrated simulation shows that the fast-ignition conditions could be achieved when two 2.8 petawatt heating laser pulses counter-propagate along a 3.5 kilotesla external magnetic field. Within a period of 5 picoseconds, the laser pulses heat a nuclear fuel to reach the ignition conditions. Furthermore, we present the parameter windows of lasers and magnetic fields required for ignition for experimental test.

  13. Ignition tuning for the National Ignition Campaign

    OpenAIRE

    Landen O.; Edwards J; Haan S. W.; Lindl J.D.; Boehly T.R.; Bradley D.K.; Callahan D.A.; Celliers P.M.; Dewald E.L.; Dixit S.; Doeppner T.; Eggert J.; Farley D.; Frenje J.A.; Glenn S.

    2013-01-01

    The overall goal of the indirect-drive inertial confinement fusion [1] tuning campaigns [2] is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics [3] used in our radiation-hydrodynamic computational models, and by checking for and resolving unexpected shot-to-shot variability in performance [4]. This has been started successfully using a variety of surrogate capsules that set key laser, hohlraum and caps...

  14. Considérations sur la cité antique

    OpenAIRE

    Grell, Chantal

    2015-01-01

    L’observation des édifices D’après les textes que nous avons précédemment cités, il ressort que les voyageurs ont une vision traditionnelle des monuments. Ils comparent implicitement le théâtre qu’ils regardent, aux théâtres romains connus. Les visiteurs prennent des mesures ; évaluent la capacité ; observent l’agencement des ordres — dorique, ionique, corinthien —, et passent en revue, les uns après les autres, les éléments communs à tout théâtre : les gradins, la scène, le mur de scène etc…...

  15. La Cité Universitaire Internationale de Paris

    Directory of Open Access Journals (Sweden)

    Sébastien Bureau

    2008-05-01

    Full Text Available La Cité Internationale Universitaire de Paris est le lieu où se concentrent le plus de résidences universitaires en Île-de-France avec une vocation affichée d’accueillir les étudiants et chercheurs du monde entier, et ce depuis 1925. Elle leur offre un ensemble de services centralisés et un cadre privilégié mais se considère avant tout comme un creuset pour la rencontre des cultures et la diffusion de la culture française parmi les élites intellectuelles internationales. Au-delà des intentions, nous avons cherché, par la rencontre de ses dirigeants et des résidents, à saisir d’une part, la réalité actuelle des échanges culturels promus par une politique du « brassage » et d’autre part, la dynamique de « l’espace vécu » des résidents.The Cité Internationale of Paris is the place where concentrate most university halls of residence in the French capital with a displayed vocation to welcome the students and the researchers of the whole world since 1925. It offers to them a set of centralized services and a privileged living environment but considers itself above all as a melting pot for the meeting of cultures and the spreading of French culture among international intellectual elites. Beyond intentions, we tried, by the meeting of managements and residents, to grasp the current reality of cultural exchanges thanks to the policy of the "mixing" and the dynamic of "the space lived" on residents.

  16. [11C]β-CIT, a cocaine analogue. Preparation, autoradiography and preliminary PET investigations

    International Nuclear Information System (INIS)

    β-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane) is a cocaine analogue with a high affinity for the dopamine transporter. [11C]β-CIT was prepared by N-methylation of nor-β-CIT with [11C]methyl iodide. The total radiochemical yield of [11C]β-CIT was 40-50% with an overall synthesis time of 35-40 min. The radiochemical purity was > 99% and the specific radioactivity at the time of injection was about 1000 Ci/mmol (37 GBq/μmol). Autoradiographic examination of [11C]β-CIT binding in human brains post-mortem demonstrated a high level of specific binding in the striatum. PET examination of [11C]β-CIT in a Cynomolgus monkey showed a marked accumulation of radioactivity in the striatum. The ratio of radioactivity in the striatum-to-cerebellum approached 5 after 87 min. In a displacement experiment, radioactivity in the striatum but not in the cerebellum, was markedly reduced after injection of unlabelled cocaine. [11C]β-CIT has a potential as ligand for PET examination of cocaine effects in man. (author)

  17. Why the EU-15 Maintains Higher CIT Rates than the New Member States?

    Directory of Open Access Journals (Sweden)

    Karpowicz Andrzej

    2014-11-01

    Full Text Available The European Union is not a homogenous area. This lack of homogeneity extends to taxes, which vary across jurisdictions. On average, Western Europe imposes significantly higher taxes on capital than New Member States, which joined the Community in 2004 and 2007. Often this fact is simply taken for granted. However, there are several arguments that can explain this variance. Although several of these arguments are well known and have been researched, they have not been assessed in combination, or used in a comparative analysis of corporate income tax (CIT rates between EU member states. Because of interest in harmonizing CIT throughout the EU, the roots of divergent CIT is of particular and timely value. Therefore, this article we attempts to demonstrate the differences in CIT rates in the EU-15 and New Member States. In so doing the general characteristics of these country grouping is identified, and then discussed in the context of the taxation theory.

  18. Gasifier burner ignition system

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    The BI-GAS pilot plant is designed such that its lower region (Stage I) is the combustion zone where oxygen and steam contact and react with recycled char. As with other combustion systems, provisions must be made to initiate combustion at start-up, to reinitiate combustion in case of a process upset where combustion is lost, and to continuously monitor the presence of combustion. An ignition system had to be developed, capable of reliable and repeated operation at pressures up to 1500 psi in a methane-rich or otherwise reducing atmosphere. The initial development work was done by Babcock and Wilcox and included development of both the ignitor system and the flame confirmation system. B and W's initial proposal specifically dealt with investigating a hypergolic (chemical auto-combustion) igniter. Hypergolic ignition is the spontaneous combustion of a compound upon contact with an oxygen containing media. This oxygen source includes air, oxygen, carbon dioxide, and water. The liquid compound studied was triethylaluminum (Al(C/sub 2/H/sub 5/)/sub 3/) otherwise identified as TEA and supplied by Ethyl Corporation, Baton Rouge, Louisiana. The hypergolic ignition system has been operated successfully and proved reliable at high pressure (750 psig) through repeated testing over a three-year period. The system designed by Stearns-Roger based on the study by Babcock and Wilcox was basically correct. Two relatively minor design defects and operational revisions to improve performance were accomplished by on-site personnel with little expenditure of time or money. The remaining problems currently experienced with the TEA ignition system are considered minor. Further work should continue to determine the lowest possible TEA concentration that can be used and still provide consistent ignition, and the system should be tested soon at the full design operating pressure of 1500 psig.

  19. Effect of fentanyl on 125I-β-CIT uptake in mice brain

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of fentanyl on 125I-2β-carbomethoxy-3β-(4-iodophenyl) tropane (125I-β-CIT) uptake in mice brain. Methods: 1) KM mice groups of five were given different doses of fentanyl, and 10 min or 1 h later were given a dose of 125I-β-CIT. 2)Two groups of animals were killed at 2 h after injection of 125I-β-CIT. 3)One group of animals were killed at 1 h after injection of 125I-β-CIT. Results: 1)In the striatum, frontal cortex, hippocampus, brain stem, cerebellum and whole brain, a dose-dependent increase in uptake (%ID/g or %ID) of 125I-β-CIT was detected at the fentanyl doses ranging from 125 to 300 μg/kg, and the uptakes of hippocampus and cerebellum were higher than that of the controls. There was a great difference in the value of %ID/g or %ID between the group treated with 250 μg/kg fentanyl and the control group; while at the doses from 12.5 to 100 μg/kg, a dose-dependent decrease in uptake in the same regions was observed and all the uptake levels were lower (hippocampus: except 62.5 and 12.5 μg/kg groups; brain stem: except 62.5 μg/kg group) than that of the controls. 2)The uptakes of 125I-β-CIT in the striatum, frontal cortex, hippocampus, brain stem, cerebellum and whole brain in the groups injected with 125I-β-CIT 10 min after fentanyl treatment were higher than that in the groups injected with 125I-β-CIT 1 h after fentanyl treatment. 3)The binding of 125I-β-CIT in the striatum, frontal cortex, hippocampus, brain stem, cerebellum and whole brain in the groups killed at 1 h after injection of 125I-β-CIT was higher than that in the control group, but without significant difference. Conclusion: Fentanyl may have different effects on 125I-β-CIT at various time points and doses

  20. Impact of a web-supported programme of Constraint Induced Therapy following stroke (LifeCIT)

    OpenAIRE

    Meagher, Claire; Hughes, Ann-Marie; Alt, Claudia H. S.; Pollet, Sebastien; Yardley, Lucy; Burridge, J.H.

    2015-01-01

    Background: upper extremity (UE) movement is often compromised following a stroke. Constraint Induced Therapy (CIT) is an evidence-based intensive intervention (1) which involves people with stoke practicing activites with their affected hand whilst wearing a mitt on their other hand, but it relies on intensive therapy. A study trialling CIT in a community setting without a therapist present found key barriers to be lack of motivation to wear the mitt and comply with the exercise programme (...

  1. Preparation and Imaging of [{sup 124}I]IPT, [{sup 124}I]{beta}-CIT, [{sup 124}I]FP-CIT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyo Chul; Choi, Tae Hyun; Kim, Kyeong Min [Korea institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)] (and others)

    2006-07-01

    The dopamine transporter is a protein localized presynaptically on dopaminergic nerve terminals. The in vivo imaging of the dopamine transporter in the human brain with PET or single photon emission computer tomography (SPECT) may be useful for monitoring degenerative brain disorders such as Parkinson's disease. Within 10 years, several radioligands have been developed mainly for use in in vitro studies. For in vivo binding to the dopamine transporter, much attention has been given to the development of cocaine analogues based on the phenyltropane moiety, such as 2{beta}- carbomethoxy-3{beta}-(4-chlorophenyl)-8-([Z]-3-iodopropen- 1-yl)nortropane (IPT), 2{beta}-carbomethoxy-3{beta}-(4- iodophenyl)tropane ({beta}-CIT), N-3-fluoropropyl-2{beta}- carbomethoxy-3{beta}-(4-iodophenyl)nortropane (FP-CIT) or the fluoro analogue {beta}-CFT. The structure of {beta}-CIT and FP-CIT allow labeling with {sup 123}I in the aromatic ring and IPT allows labeling with {sup 123}I in the olefin for SPECT studies or with 11C (t{sub 1/2} 20 min) in the Nmethyl group or with 18F (t{sub 1/2} = 109.7 min) in the Nfluoroalkyl group for PET studies. An advantage with radiolabeled {beta}-CIT and FP-CIT are that direct comparisons can be made between the results of the two imaging techniques, whereas IPT can only be used for SPECT. A problem with the quantity of {beta}-CIT and FPCIT binding to the dopamine transporter is that the uptake of radioactivity in the dopamine-transporter rich striatum increases with time and does not reach equilibrium within the time of a PET examination 4. By following the kinetics of [{sup 123}I]{beta}-CIT with SPECT, a binding equilibrium in the striatum was not reached for more than 18 h. There is a need for a radioligand for the dopamine transporter that gives an equilibrium within the time limit of a PET study (90 to 120 min) and that can be used for quantity of dopamine transporters in the human brain with the high-resolution PET cameras. Recently, new long

  2. Ignition Studies on Aluminised Propellant.

    Directory of Open Access Journals (Sweden)

    K. A. Bhaskaran

    1996-12-01

    Full Text Available An experimental investigation on the ignition of metallised propellants (APIHTPB/AI has been carried out 10 determine the ignition delay, minimum ignition energy and corresponding heat flux,threshold heat flux for ignition and minimum ignition temperature, Ignition experiments were conductedusing a shock tube under convectiveheating conditions similar to those prevailingin a rocket motor. Heat flux at propellant location was measured by thin film heat flux gauge and also calculated from a ribbon thermocouple output under similar test conditions. The igntion delay was measured as the time lag between the arrival of hot gas at the propellant and the light emission due to actual ignition of the propellant. The experimental results indicate that the ignition delay characteristics are independent of pressure. The minimum energy for ignition obtained for the propellant is 1100J/m2 corresponding to the heat flux range of 80·120 WIcm2 for a gas velocity of 110 mls. The threshold heat flux required to ignite the propellant was 40 W/cm2 at a velocity of 110 mls. Heat flux corresponding to minimum ignition energy and the threshold heat flux increase with gas velocity. The threshold ignition temperature of the propellant was found to be 600 ± 20 K.

  3. Ignition in near term D-3He tokamak reactors: Appendix B

    International Nuclear Information System (INIS)

    The prospects for achieving breakeven and ignition in near term ETR type tokamaks under D/He-3 relevant conditions are considered. Using present scaling laws for beta in the first stability regime, it is found that CIT may be close to breakeven with the presently planned toroidal magnetic field system, if the ASDEX H-mode scaling law is used. With Kaye-Goldston scaling, Q = .22 can be attained, but this requires an excessive amount of rf heating power. Larger devices, such as NET/INTOR, can ignite with ASDEX H-mode scaling with an increase of the toroidal field by 20% and removal of the blanket and reduction of the inboard shield to that required for D/He-3. 5 refs., 4 figs., 2 tabs

  4. Syntactic Defi cits in Autism: Can Interactive Technologies Help?

    Directory of Open Access Journals (Sweden)

    Vanja Kljajevic

    2010-06-01

    Full Text Available Sentence comprehension critically depends on our ability to decode syntactic information. Autistic individuals have diffi culty decoding and encoding syntactic information. Traditional treatments of syntactic defi cits in autism seem to neglect the idea that improvement of syntactic abilities in individuals with this disorder may occur via atypical cognitive pathways. Recent research on autism lends the theoretical grounds to the idea that autistic brain processes some types of information in atypical ways. It is not clear at the moment how and to what extent specifi c cognitive components can compensate for impaired processing in autism, but there is evidence indicating that treatments specifi cally designed to strengthen certain abilities in autism may be successful even when they rely on atypical cognitive pathways. As an example, the present paper explores the possibility of employing pictorial reasoning, which is typically spared in autistic individuals, in a treatment intended to strengthen these individuals’ syntactic abilities. Interactive systems - robotic and soft ware - are viewed as indispensable tools in such treatments, bringing together cognitive science, neurology, and social robotics. In terms of actual design, this approach opens up space in which creativity in employing interactive systems for therapeutic purposes could fl ourish. In terms of theory, learning via atypical pathways opens the questions on the principles governing atypical information structuring, its neural underpinnings, and transfer of skills acquired through interactive therapeutic devices to everyday life situations. interactive systems.

  5. Putative resistance genes in the CitEST database

    Directory of Open Access Journals (Sweden)

    Simone Guidetti-Gonzalez

    2007-01-01

    Full Text Available Disease resistance in plants is usually associated with the activation of a wide variety of defense responses to prevent pathogen replication and/or movement. The ability of the host plant to recognize the pathogen and to activate defense responses is regulated by direct or indirect interaction between the products of plant resistance (R and pathogen avirulence (Avr genes. Attempted infection of plants by avirulent pathogens elicits a battery of defenses often followed by the collapse of the challenged host cells. Localized host cell death may help to prevent the pathogen from spreading to uninfected tissues, known as hypersensitive response (HR. When either the plant or the pathogen lacks its cognate gene, activation of the plant’s defense responses fails to occur or is delayed and does not prevent pathogen colonization. In the CitEST database, we identified 1,300 reads related to R genes in Citrus which have been reported in other plant species. These reads were translated in silico, and alignments of their amino acid sequences revealed the presence of characteristic domains and motifs that are specific to R gene classes. The description of the reads identified suggests that they function as resistance genes in citrus.

  6. CIT in developing countries: The case of Trinidad and Tobago

    Directory of Open Access Journals (Sweden)

    Bajić-Brković Milica

    2005-01-01

    Full Text Available Trinidad and Tobago is faced with the challenge of developing strategies to integrate successfully in the new knowledge economy. Many governmental actions towards "wiring" the nation are currently taking place. Creation of the "intelligent nation" is among country's national development objectives. Vis-a-vis plans yet to be designed and implemented over the next ten years there is a reality of the www option that has gained a momentum, and is already playing an important role in Trinidad and Tobago. While during the first years the www has been accepted as a medium for communicating and sharing information, today it has moved onto the next generation transforming into the development supporting tool. The experience of Trinidad and Tobago in using the CIT-based alternative is the focus of this paper. It explores the state of the art in the field, and discusses the way the alternative has been utilized so far in the country's development and management practice. It also identifies the potentials for further development, and suggests a number of proposals for future strategies and actions.

  7. Cooperating internationally. US/Japan Civil Industrial Technologies (CIT) Arrangement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The Civil Industrial Technologies (CIT) Arrangement was signed in July 1994 between governments of the US and Japan. Areas of research range from scientific and technical databases and bioprocessing to precompetitive processing of functionally-gradient materials and ceramics. Papers presented in this symposium include studies on thin polymer films generated by vapor deposition polymerization, development of manufacturing technique of fusing 3D C/C composite materials, measurement and analysis for high performance computing systems, low-cost fabrication of ceramic components, bioprocessing, data exchange for mass spectral databases, development of high performance aluminum nitride ceramics, precompetitive processing of functionally-gradient materials, purity determination of organic reference materials, definitive methods traceable to SI unit, development of biocompatible artificial hard tissue materials, development of photoassisted catalysis technologies, surface analysis for catalysts by electron spectroscopy, development of ultra-solid lubricant with cluster diamond, precise determination of impurities in high-purity rare-earth metals, and highly accurate acceleration measurement system. 22 refs., 86 figs., 3 tabs.

  8. Compact proton spectrometers for measurements of shock

    Energy Technology Data Exchange (ETDEWEB)

    Mackinnon, A; Zylstra, A; Frenje, J A; Seguin, F H; Rosenberg, M J; Rinderknecht, H G; Johnson, M G; Casey, D T; Sinenian, N; Manuel, M; Waugh, C J; Sio, H W; Li, C K; Petrasso, R D; Friedrich, S; Knittel, K; Bionta, R; McKernan, M; Callahan, D; Collins, G; Dewald, E; Doeppner, T; Edwards, M J; Glenzer, S H; Hicks, D; Landen, O L; London, R; Meezan, N B

    2012-05-02

    The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign (NIC) diagnostic. The WRF measures the spectrum of protons from D-{sup 3}He reactions in tuning-campaign implosions containing D and {sup 3}He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total {rho}R through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.

  9. Catalytic ignition of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    K. L. Hohn; C.-C. Huang; C. Cao

    2009-01-01

    Catalytic ignition refers to phenomenon where sufficient energy is released from a catalytic reaction to maintain further reaction without additional extemai heating. This phenomenon is important in the development of catalytic combustion and catalytic partial oxidation processes, both of which have received extensive attention in recent years. In addition, catalytic ignition studies provide experimental data which can be used to test theoretical hydrocarbon oxidation models. For these reasons, catalytic ignition has been frequently studied. This review summarizes the experimental methods used to study catalytic ignition of light hydrocarbons and describes the experimental and theoretical results obtained related to catalytic ignition. The role of catalyst metal, fuel and fuel concentration, and catalyst state in catalytic ignition are examined, and some conclusions are drawn on the mechanism of catalytic ignition.

  10. Evaluation of novel tropane analogues in comparison with the binding characteristics of [18F]FP-CIT and [131I]β-CIT

    International Nuclear Information System (INIS)

    This study evaluated novel potential dopamine transporter (DAT) inhibitors as ligands for positron emission tomography. Five new tropane analogs were synthesized and compared with the known ligand 2β-carbomethoxy-3β-(4-iodophenyl)tropane (β-CIT) and the recently characterized ligands N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methylphenyl)-nortropane (PE2I) and 2β-carbofluoroethoxy-3β-(4-methylphenyl)tropane (FETT). Evaluation with autoradiography measured the ability to antagonize the binding of [131I]iodine-labeled β-CIT and [18F]fluorine-labeled N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodo-phenyl) nortropane in rat and pig brains. The standards for comparison (PE2I and FETT) competed strongly in all regions investigated (striatum, cortex, superior colliculus and cerebellum). Of the new compounds, 2α-amido-fluoroethyl-3β-(4-iodophenyl)tropane () and 2β-amido-fluoroethyl-3β-(4-iodophenyl)tropane () competed strongly with [131I]β-CIT in DAT-rich striatum, but also in other brain regions suggesting poor DAT selectivity. Because [131I]β-CIT binds unselectively both to DAT and serotonin transporters, no definite conclusion about the selectivity of the new compounds is possible. However, preclinical studies using the compounds and labeled with fluorine-18 or iodine-131 are encouraged.

  11. Concept of laser fusion power plant based on fast ignition

    International Nuclear Information System (INIS)

    Recent progress on fast ignition (FI) and cooled Yb:YAG ceramic laser enable us to design an IFE power plant with a 1MJ-class, compact laser whose output energy is 1/4 of previous central ignition scheme. Basing on the FI scheme, we conceptually designed a laser fusion power plant driven with cooled-Yb:YAG, ceramic lasers. The cooled Yb-YAG ceramic was newly chosen as the laser material. We found that the heating laser for ignition could be constructed with the cooled Yb:YAG ceramics as well as the compression laser with acceptable electricity-laser conversion efficiencies including the electric power for the cooling system. A new reactor scheme for a liquid wall reactor that has no stagnation point of ablated gas was proposed. (author)

  12. The physics of an ignited tokamak

    International Nuclear Information System (INIS)

    There appears to be a consensus that time has come to embark on the design and construction of the next generation of tokamaks which is at the origin of the ITER initiative. Different proposals have been made based on different appreciation as to the size of the step which can be taken, related to considerations of cost, risk and duration of construction. A class of devices which may be considered the last the very high-field, high density ALCATOR-Frascati line of tokamaks have been proposed for some years specifically for this purpose. Today there remain three such projects: Ignitor, Ignitex and CIT. The technology chosen limits the pulse length to a few seconds. These devices have evolved through the years becoming larger and much more expensive than originally anticipated, increasing the pressure to do more than just a simple demonstration of ignition. There is another class of more ambitious devices which aim at creating long burning plasmas in conditions as close as possible to those of a tokamak reactor in order to address all the plasma physics problems associated with long burn. Three such projects, NET, the european next step after JET, ITER and JIT are good examples of this approach. The ideal would be to design a device with sufficient margin to study burning plasmas over a wide range of parameters. The object of this didactic presentation is to describe the common physics basis of all these projects, compare their expected performance using present knowledge and list the physics problems associated with a burning plasma experiment. The comparison is not meant to be a judgement since the important parameter is the cost/benefit ratio which is a matter of appreciation at this stage. 6 refs., 3 figs., 1 tab

  13. Monolithic catalytic igniters

    Science.gov (United States)

    La Ferla, R.; Tuffias, R. H.; Jang, Q.

    1993-01-01

    Catalytic igniters offer the potential for excellent reliability and simplicity for use with the diergolic bipropellant oxygen/hydrogen as well as with the monopropellant hydrazine. State-of-the-art catalyst beds - noble metal/granular pellet carriers - currently used in hydrazine engines are limited by carrier stability, which limits the hot-fire temperature, and by poor thermal response due to the large thermal mass. Moreover, questions remain with regard to longevity and reliability of these catalysts. In this work, Ultramet investigated the feasibility of fabricating monolithic catalyst beds that overcome the limitations of current catalytic igniters via a combination of chemical vapor deposition (CVD) iridium coatings and chemical vapor infiltration (CVI) refractory ceramic foams. It was found that under all flow conditions and O2:H2 mass ratios tested, a high surface area monolithic bed outperformed a Shell 405 bed. Additionally, it was found that monolithic catalytic igniters, specifically porous ceramic foams fabricated by CVD/CVI processing, can be fabricated whose catalytic performance is better than Shell 405 and with significantly lower flow restriction, from materials that can operate at 2000 C or higher.

  14. Equilibrium system analysis in a tokamak ignition experiment

    International Nuclear Information System (INIS)

    The objective of the IGNITEX Project is to produce and control ignited plasmas for scientific study in the simplest and least expensive way possible. The original concept was proposed by both physics and engineering researchers along the following line of thought. Question: Is there any theoretically simple, compact and reliable way of achieving fusion ignition according to the results of the fusion research program for the last decades? Answer: Yes. An experiment to be carried out in an ohmically heated compact tokamak device with 20 T field on plasma axis. Question: Is there any practical way to carry out that experiment at low cost in the near term? Answer: Yes. Using a single-turn coil magnet system with homopolar power supplies

  15. Equilibrium system analysis in a tokamak ignition experiment

    Energy Technology Data Exchange (ETDEWEB)

    Carrera, R.; Weldon, W.F.; Woodson, H.H.

    1989-10-01

    The objective of the IGNITEX Project is to produce and control ignited plasmas for scientific study in the simplest and least expensive way possible. The original concept was proposed by both physics and engineering researchers along the following line of thought. Question: Is there any theoretically simple, compact and reliable way of achieving fusion ignition according to the results of the fusion research program for the last decades Answer: Yes. An experiment to be carried out in an ohmically heated compact tokamak device with 20 T field on plasma axis. Question: Is there any practical way to carry out that experiment at low cost in the near term Answer: Yes. Using a single-turn coil magnet system with homopolar power supplies.

  16. Equilibrium system analysis in a tokamak ignition experiment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Carrera, R.; Weldon, W.F.; Woodson, H.H.

    1989-10-01

    The objective of the IGNITEX Project is to produce and control ignited plasmas for scientific study in the simplest and least expensive way possible. The original concept was proposed by both physics and engineering researchers along the following line of thought. Question: Is there any theoretically simple, compact and reliable way of achieving fusion ignition according to the results of the fusion research program for the last decades? Answer: Yes. An experiment to be carried out in an ohmically heated compact tokamak device with 20 T field on plasma axis. Question: Is there any practical way to carry out that experiment at low cost in the near term? Answer: Yes. Using a single-turn coil magnet system with homopolar power supplies.

  17. 123I-β-CIT SPECT imaging study in early Parkinson's disease

    International Nuclear Information System (INIS)

    Purpose: To investigate the loss of dopamine transporters in hemi-Parkinson's disease (PD) using 123I-β-CIT/SPECT. Methods: Seven patients with hemi-Parkinson's disease and 7 age- and sex- matched healthy subjects were studied by 123I-β-CIT/SPECT. Striatal specific uptake of 123I-β-CIT was calculated in the ratio of striatal uptake to cerebellar uptake. Results: Mean striatal specific uptake of 123I-β-CIT in healthy subjects was 3.0 +- 0.5 and 5.5 +- 0.6 at 3h and 18h after injection. Striatal specific uptake in contralateral to the clinical symptom side was 2.0 +- 0.8 and 3.1 +- 0.4; in ipsilateral striatum was 2.3 +- 0.4 and 4.0 +- 0.5. There was a significant reduction of striatal tracer uptake in PD patients compared to the controls. Patient age correlated with the reduction in contralateral striatum but did not correlate with that in ipsilateral striatum. Conclusions: Striatal dopamine transporters bilaterally lost in early PD patients. 123I-β-CIT uptake in contralateral striatum was reduced more severely than in ipsilateral striatum

  18. Ignition target design for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Haan, S.W.; Pollaine, S.M.; Lindl, J.D. [Los Alamos National Laboratory, NM (United States)] [and others

    1996-06-01

    The goal of inertial confinement fusion (ICF) is to produce significant thermonuclear burn from a target driven with a laser or ion beam. To achieve that goal, the national ICF Program has proposed a laser capable of producing ignition and intermediate gain. The facility is called the National Ignition Facility (NIF). This article describes ignition targets designed for the NIF and their modeling. Although the baseline NIF target design, described herein, is indirect drive, the facility will also be capable of doing direct-drive ignition targets - currently being developed at the University of Rochester.

  19. Practical benefit of [123I[FP-CIT SPET in the demonstration of the dopaminergic deficit in Parkinson's disease

    International Nuclear Information System (INIS)

    Loss of striatal dopamine (DA) transporters in Parkinson's disease (PD) has been accurately assessed in vivo by single-photon emission tomography (SPET) studies using [123I[β-CIT. However, these studies have also shown that adequate imaging of the striatal DA transporter content can be performed only 20-30 h following the injection of [123I[β-CIT, which is not convenient for routine out-patient evaluations. Recently, a new ligand, N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)tropane (FP-CIT), became available for in vivo imaging of the DA transporter. The faster kinetics of [123I[FP-CIT have been shown to allow adequate acquisition as early as 3 h following injection. In the present study, loss of striatal DA transporters in five non-medicated PD patients was assessed on two consecutive SPET scans, one with [123I[β-CIT (24 h following injection) and one with [123I[FP-CIT (3 h following injection). The ratios of specific to non-specific [123I[FP-CIT uptake in the caudate nucleus and putamen were consistently 2.5-fold lower than those of [123I[β-CIT. However, when the uptake ratio of both ligands in these brain regions of patients was expressed as a percentage of the uptake ratio found in healthy controls, both the decrease and the variation of the data were similar. It is concluded on the basis of these findings that [123I[FP-CIT seems as good as [123I[β-CIT for the assessment of the dopaminergic deficit in PD. The faster kinetics of [123I[FP-CIT are a clear advantage. (orig.). With 3 figs

  20. Central ignition scenarios for TFTR

    International Nuclear Information System (INIS)

    The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs

  1. Conceptual Design of a Fast-Ignition Laser Fusion Reactor FALCON-D

    OpenAIRE

    Goto, T.; Ogawa, Y; Hiwatari, R.; Asaoka, Y; Okano, K.; Someya, Y; Sunahara, A.; T. Johzaki

    2008-01-01

    A new conceptual design of the laser fusion power plant FALCON-D (Fast ignition Advanced Laser fusion reactor CONcept with a Dry wall chamber) has been proposed. The fast ignition method can achieve the sufficient fusion gain for a commercial operation (~100) with about 10 times smaller fusion yield than the conventional central ignition method. FALCON-D makes full use of this property and aims at designing with a compact dry wall chamber (5~6m radius). 1-D/2-D hydrodynamic simulations showed...

  2. Compact Lumps

    CERN Document Server

    Bazeia, D; Menezes, R

    2015-01-01

    We study the presence of lumplike solutions in models described by a single real scalar field with standard kinematics in two-dimensional spacetime. The results show several distinct models that support the presence of bell-shaped, lumplike structures which may live in a compact space.

  3. Extrastriatal binding of [¹²³I]FP-CIT in the thalamus and pons

    DEFF Research Database (Denmark)

    Koch, Walter; Unterrainer, Marcus; Xiong, Guoming; Bartenstein, Peter; Diemling, Markus; Varrone, Andrea; Dickson, John C; Tossici-Bolt, Livia; Sera, Terez; Asenbaum, Susanne; Booij, Jan; Kapucu, Ozlem L; Kluge, Andreas; Ziebell, Morten; Darcourt, Jacques; Nobili, Flavio; Pagani, Marco; Hesse, Swen; Vander Borght, Thierry; Van Laere, Koen; Tatsch, Klaus; la Fougère, Christian

    2014-01-01

    PURPOSE: Apart from binding to the dopamine transporter (DAT), [(123)I]FP-CIT shows moderate affinity for the serotonin transporter (SERT), allowing imaging of both monoamine transporters in a single imaging session in different brain areas. The aim of this study was to systematically evaluate...... error) of 8.2 ± 1.3 % for the thalamus and 6.8 ± 2.9 % for the pons was shown. CONCLUSION: The potential to evaluate extrastriatal predominant SERT binding in addition to the striatal DAT in a single imaging session was shown using a large database of [(123)I]FP-CIT scans in healthy controls. For both...... using [(123)I]FP-CIT for DAT imaging in patients treated with selective serotonin reuptake inhibitors....

  4. The preclinical pharmacological study of dopamine transporter imaging agent 18F-FP-β-CIT

    Institute of Scientific and Technical Information of China (English)

    LI Xiaomin; CHEN Zhengping; WANG Songpei; TANG Jie; LIN Yansong; ZHU Zhaohui; FANG Ping

    2007-01-01

    The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β- carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444,0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum,striatum/frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.

  5. Molecular and immunological characterization of the glycosylated orange allergen Cit s 1.

    Science.gov (United States)

    Pöltl, Gerald; Ahrazem, Oussama; Paschinger, Katharina; Ibañez, M Dolores; Salcedo, Gabriel; Wilson, Iain B H

    2007-02-01

    The IgE of sera from patients with a history of allergy to oranges (Citrus sinensis) binds a number of proteins in orange extract, including Cit s 1, a germin-like protein. In the present study, we have analyzed its immunological cross-reactivity and its molecular nature. Sera from many of the patients examined recognize a range of glycoproteins and neoglycoconjugates containing beta1,2-xylose and core alpha1,3-fucose on their N-glycans. These reagents also inhibited the interaction of Cit s 1 with patients' sera, thus underlining the critical role of glycosylation in the recognition of this protein by patients' IgE and extending previous data showing that deglycosylated Cit s 1 does not possess IgE epitopes. In parallel, we examined the peptide sequence and glycan structure of Cit s 1, using mass spectrometric techniques. Indeed, we achieved complete sequence coverage of the mature protein compared with the translation of an expressed sequence tag cDNA clone and demonstrated that the single N-glycosylation site of this protein carries oligosaccharides with xylose and fucose residues. Owing to the presumed requirement for multivalency for in vivo allergenicity, our molecular data showing that Cit s 1 is monovalent as regards glycosylation and that the single N-glycan is the target of the IgE response to this protein explain the immunological cross-reactive properties of Cit s 1 as well as its equivocal nature as a clinically relevant allergen. PMID:17095532

  6. Laïcité and multiculturalism: the Stasi Report in context.

    Science.gov (United States)

    Akan, Murat

    2009-06-01

    French republican universalism--expressed most strongly in the principle and practice of laïcité--and multiculturalism have constituted opposite poles on questions of citizenship and integration. The report of the Stasi Commission on laïcité on 11 December 2003 and the following legislation on the donning of religious symbols in French public schools have once again, spurred debates over the meanings and practices of laïcité. The report and the law have been interpreted in different ways. Some have presented them as a reaffirmation of a historically constituted laïcité under new circumstances, others as a divergence from the real problems of racism, unemployment and gender inequality. In this article, I offer an alternative reading by supplementing a critical reading of the report with an analysis of its historical and immediate institutional context. I evaluate the Stasi Report in its immediate context of institutional change, and in the historical context of selected developments concerning laïcité since the 1905 law separating churches and State. I argue that the Stasi Report marks a fundamental break with French republican universalism, and I show that this break occurred contemporaneously with key gestures of multiculturalism: the establishment of the French Muslim Council and the creation of Muslim high schools under contract with the French state. This double movement to narrow the boundaries of laïcité, and for the state to expand the boundaries of identity-specific, Muslim public institutions and private schooling constitutes a reorganization of the public sphere in France which qualifies as a move towards multiculturalism. PMID:19489818

  7. Dopamine transporter imaging with [{sup 123}I]FP-CIT SPECT: potential effects of drugs

    Energy Technology Data Exchange (ETDEWEB)

    Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands); Kemp, Paul [Southampton University Hospitals Trust, Department of Nuclear Medicine, Southampton (United Kingdom)

    2008-02-15

    [{sup 123}I]N-{omega}-fluoropropyl-2{beta}-carbomethoxy-3{beta}-{l_brace}4-iodophenyl{r_brace}nortropane ([{sup 123}I]FP-CIT) single photon emission computed tomography (SPECT) is a frequently and routinely used technique to detect or exclude dopaminergic degeneration by imaging the dopamine transporter (DAT) in parkinsonian and demented patients. This technique is also used in scientific studies in humans, as well as in preclinical studies to assess the availability of DAT binding in the striatum. In routine clinical studies, but also in scientific studies, patients are frequently on medication and sometimes even use drugs of abuse. Moreover, in preclinical studies, animals will be anesthetized. Prescribed drugs, drugs of abuse, and anesthetics may influence the visual interpretation and/or quantification of [{sup 123}I]FP-CIT SPECT scans. Here, we discuss the basic principle of how drugs and anesthetics might influence the visual interpretation and/or quantification of [{sup 123}I]FP-CIT SPECT scans. We also review drugs which are likely to have a significant influence on the visual interpretation and/or quantification of [{sup 123}I]FP-CIT SPECT scans. Additionally, we discuss the evidence as to whether frequently prescribed drugs in parkinsonian and demented patients may have an influence on the visual interpretation and/or quantification of [{sup 123}I]FP-CIT SPECT scans. Finally, we discuss our recommendations as to which drugs should be ideally withdrawn before performing a [{sup 123}I]FP-CIT SPECT scan for routine clinical purposes. The decision to withdraw any medication must always be made by the specialist in charge of the patient's care and taking into account the pros and cons of doing so. (orig.)

  8. Dopamine transporter imaging with [123I]FP-CIT SPECT: potential effects of drugs

    International Nuclear Information System (INIS)

    [123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-{4-iodophenyl}nortropane ([123I]FP-CIT) single photon emission computed tomography (SPECT) is a frequently and routinely used technique to detect or exclude dopaminergic degeneration by imaging the dopamine transporter (DAT) in parkinsonian and demented patients. This technique is also used in scientific studies in humans, as well as in preclinical studies to assess the availability of DAT binding in the striatum. In routine clinical studies, but also in scientific studies, patients are frequently on medication and sometimes even use drugs of abuse. Moreover, in preclinical studies, animals will be anesthetized. Prescribed drugs, drugs of abuse, and anesthetics may influence the visual interpretation and/or quantification of [123I]FP-CIT SPECT scans. Here, we discuss the basic principle of how drugs and anesthetics might influence the visual interpretation and/or quantification of [123I]FP-CIT SPECT scans. We also review drugs which are likely to have a significant influence on the visual interpretation and/or quantification of [123I]FP-CIT SPECT scans. Additionally, we discuss the evidence as to whether frequently prescribed drugs in parkinsonian and demented patients may have an influence on the visual interpretation and/or quantification of [123I]FP-CIT SPECT scans. Finally, we discuss our recommendations as to which drugs should be ideally withdrawn before performing a [123I]FP-CIT SPECT scan for routine clinical purposes. The decision to withdraw any medication must always be made by the specialist in charge of the patient's care and taking into account the pros and cons of doing so. (orig.)

  9. Feasibility study of a compact ignition fusion experiment (IGNITOR)

    International Nuclear Information System (INIS)

    The study deals with the main problems concerning the feasibility of an Ignitor machine. The reference design considered is that with circular cross-section of the toroidal chamber. First a simple mechanical configuration is outlined which would allow easy assembling and disassembling procedures. A mechanical precompression system is proposed. Second a careful tridimensional analysis in the elastic and elastoplastic state is performed, assuming windings with and without reinforcing steel plates. At the end, preliminary evaluations of problems related to activation and tritium handling are given

  10. A second generation climate index for tourism (CIT): specification and verification

    Science.gov (United States)

    de Freitas, C. R.; Scott, Daniel; McBoyle, Geoff

    2008-05-01

    Climate is a key resource for many types of tourism and as such can be measured and evaluated. An index approach is required for this task because of the multifaceted nature of weather and the complex ways that weather variables come together to give meaning to climate for tourism. Here we address the deficiencies of past indices by devising a theoretically sound and empirically tested method that integrates the various facets of climate and weather into a single index called the Climate Index for Tourism (CIT). CIT rates the climate resource for activities that are highly climate/weather sensitive, specifically, beach “sun, sea and sand” (3S) holidays. CIT integrates thermal (T), aesthetic (A) and physical (P) facets of weather, which are combined in a weather typology matrix to determine a climate satisfaction rating that ranges from very poor (1 = unacceptable) to very good (7 = optimal). Parameter A refers to sky condition and P to rain or high wind. T is the body-atmosphere energy balance that integrates the environmental and physiological thermal variables, such as solar heat load, heat loss by convection (wind) and by evaporation (sweating), longwave radiation exchange and metabolic heat (activity level). Rather than use T as a net energy (calorific) value, CIT requires that it be expressed as thermal sensation using the standard nine-point ASHRAE scale (“very hot” to “very cold”). In this way, any of the several body-atmosphere energy balance schemes available may be used, maximizing the flexibility of the index. A survey ( N = 331) was used to validate the initial CIT. Respondents were asked to rate nine thermal states (T) with different sky conditions (A). They were also asked to assess the impact of high winds or prolonged rain on the perceived quality of the overall weather condition. The data was analysed statistically to complete the weather typology matrix, which covered every possible combination of T, A and P. Conditions considered to

  11. Molecular and immunological characterisation of the glycosylated orange allergen Cit s 1

    OpenAIRE

    Pöltl, Gerald; Ahrazem, Oussama; Paschinger, Katharina; Ibañez, M Dolores; Salcedo, Gabriel; Wilson, Iain B. H.

    2006-01-01

    The IgE of sera from patients with a history of allergy to oranges (Citrus sinensis) bind a number of proteins in orange extract, including Cit s 1, a germin-like protein. In the present study, we have analysed its immunological cross-reactivity and its molecular nature. Sera from many of the patients examined recognise a range of glycoproteins and neoglycoconjugates containing β1,2-xylose and core α1,3-fucose on their N-glycans. These reagents also inhibited the interaction of Cit s 1 with p...

  12. To enlarge the travel markets from Shanghai to Turku (Shanghai CITS, Ltd.)

    OpenAIRE

    Wang, Chunyang

    2010-01-01

    This paper is made in order to make thorough analysis in current Chinese travel markets and travel agencies, as well as the analysis on Turku’s travel markets, with which it can know the feasibility in enlarge the travel markets for CITS into Turku. In details, as the background information, the brief overview of history of China’s domestic travel agencies and a brief description of Shanghai CITS in terms of its business and management status are posed with the aim of getting enough suppo...

  13. European multicentre database of healthy controls for [(123)I]FP-CIT SPECT (ENC-DAT)

    DEFF Research Database (Denmark)

    Varrone, Andrea; Dickson, John C; Tossici-Bolt, Livia; Sera, Terez; Asenbaum, Susanne; Booij, Jan; Kapucu, Ozlem L; Kluge, Andreas; Knudsen, Gitte M; Koulibaly, Pierre Malick; Nobili, Flavio; Pagani, Marco; Sabri, Osama; Vander Borght, Thierry; Van Laere, Koen; Tatsch, Klaus

    2013-01-01

    Dopamine transporter (DAT) imaging with [(123)I]FP-CIT (DaTSCAN) is an established diagnostic tool in parkinsonism and dementia. Although qualitative assessment criteria are available, DAT quantification is important for research and for completion of a diagnostic evaluation. One critical aspect of...... quantification is the availability of normative data, considering possible age and gender effects on DAT availability. The aim of the European Normal Control Database of DaTSCAN (ENC-DAT) study was to generate a large database of [(123)I]FP-CIT SPECT scans in healthy controls....

  14. Striatal [123I]β-CIT SPECT and prefrontal cognitive functions in Parkinson's disease

    International Nuclear Information System (INIS)

    Twenty non-demented patients with idiopathic Parkinson's disease (PD) underwent single photon emission computed tomography (SPECT) with [123I]β-CIT to further investigate the contribution of nigrostriatal dysfunction to cognitive and motor deficits. Compared to matched controls PD patients showed normal verbal intelligence, short-term memory and phasic alertness. There were significant (p 123I]β-CIT SPECT. These results support the view that the striatum is part of a neuronal network that is mediating prefrontal cognitive functions. (author)

  15. [{sup 123}I]FP-CIT binding in rat brain after acute and sub-chronic administration of dopaminergic medication

    Energy Technology Data Exchange (ETDEWEB)

    Lavalaye, J.; Knol, R.J.J.; Bruin, K. de; Reneman, L.; Booij, J. [Academic Medical Center, Amsterdam (Netherlands). Dept. of Nuclear Medicine; Janssen, A.G.M. [Technical Univ. Eindhoven (Netherlands). Amersham Cygne

    2000-03-01

    The recently developed radioligand [{sup 123}I]FP-CIT is suitable for clinical single-photon emission tomography (SPET) imaging of the dopamine (DA) transporter in vivo. To date it has remained unclear whether dopaminergic medication influences the striatal [{sup 123}I]FP-CIT binding. The purpose of this study was to investigate the influence of this medication on [{sup 123}I]FP-CIT binding in the brain. We used an animal model in which we administered dopaminomimetics, antipsychotics and an antidepressant. In vivo [{sup 123}I]FP-CIT binding to the DA and serotonin transporters was evaluated after sub-chronic and acute administration of the drugs. The administered medication induced small changes in striatal [{sup 123}I]FP-CIT binding which were not statistically significant. As expected, the DA reuptake blocker GBR 12,909 induced a significant decrease in [{sup 123}I]FP-CIT binding. [{sup 123}I]FP-CIT binding in the serotonin-rich hypothalamus was decreased only after acute administration of fluvoxamine. The results of this study suggest that dopaminergic medication will not affect the results of DA transporter SPET imaging with [{sup 123}I]FP-CIT. (orig.)

  16. L’origine de la cécité identifiée pour certaines formes de surdité-cécité

    OpenAIRE

    Petit, Christine

    2015-01-01

    La structure des processus caliciels (en vert) révélée au microscope électronique. © Institut Pasteur / Cataldo Schietroma et Vincent Michel Des chercheurs de l’Institut Pasteur, de l’Institut de la Vision, de l’Inserm et de l’Université Pierre et Marie Curie ont élucidé l’origine de la cécité qui survient dans le syndrome de Usher de type I (cause la plus fréquente de surdité-cécité chez l’homme). Les scientifiques ont également démontré pourquoi le rongeur, seul modèle animal disponible au...

  17. Au croisement des récits: analyse de quelques dispositifs de comunication dans la construction du récit patrimonial

    OpenAIRE

    Gellereau, Michèle

    2003-01-01

    L'article analyse quelques modes de construction du récit patrimonial au travers des dispositifs de médiation dans le mise en visite d'anciens sites industriels du Nord de la France. Il étudie comment et sous quels modes énonciatifs, la narration agit comme forme priovilégiée de médiation langagière permettant une appropriation des lieux par le visiteurs. Les dipositifs d'empilement, de mise en écho des récits peuvent créer des effets de stéréotypie auquels s'opposent des dispositifs de confr...

  18. Ignition and Inertial Confinement Fusion at The National Ignition Facility

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm3-sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIF's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY2010 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

  19. Ignition and inertial confinement fusion at the National Ignition Facility

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm3-sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIF's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY2010 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

  20. Tritium system for compact high field devices

    International Nuclear Information System (INIS)

    Some theoretical results and the current status of the work on a prototype plant for the Tritium cycle of compact high-field tokamaks (such as, Ignitor, CIT, etc.), using the SAES Getter St 707 getter material, are described in this report. The schematics and present status of the main subplants of the cycle are reported together with some experimental results demostrating the possibility of utilizing the St 707 material to purify the inert atmosphere of the glove-boxes and the secondary containment of the double-containment metal canalization which is to eventually house the various parts of the plant. Finally, as an example, the FTU machine, under construction at ENEA Frascati, has been taken as a reference, and theoretical evaluations are given for the inventory, permeation and release of the Tritium from the first wall and the thermal shieldes of such a tokamak

  1. Compact NMR

    Energy Technology Data Exchange (ETDEWEB)

    Bluemich, Bernhard; Haber-Pohlmeier, Sabina; Zia, Wasif [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMC)

    2014-06-01

    Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.

  2. Compact NMR

    International Nuclear Information System (INIS)

    Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.

  3. Rocket Ignition Demonstrations Using Silane

    Science.gov (United States)

    Pal, Sibtosh; Santoro, Robert; Watkins, William B.; Kincaid, Kevin

    1998-01-01

    Rocket ignition demonstration tests using silane were performed at the Penn State Combustion Research Laboratory. A heat sink combustor with one injection element was used with gaseous propellants. Mixtures of silane and hydrogen were used as fuel, and oxygen was used as oxidizer. Reliable ignition was demonstrated using fuel lead and and a swirl injection element.

  4. Alpha power effects on energy confinement time and ignition, and enhancement of ion neoclassical heat conduction due to electron and superthermal ion energy scattering collisions

    International Nuclear Information System (INIS)

    In Part A of the paper a purely theoretical model is adopted for the local heat diffusivities χe and χi. The global τE is constructed after Callen et al. and is used in a zero dimensional ignition power balance to study alpha power and fast alpha loss effects on ignition. The Horton-Choi-Yushmanov-Parail model for χe permits ignition in a CIT-like tokamak with B = 13.5 T, Ip = 18 MA, if the fast alpha losses and the ηi mode can be controlled. Part B considers the extra components of neoclassical ion heat conduction driven by energy scattering collisions with electrons and superthermal ions. These components are important in auxiliary heated discharges and can be the most important if the plasma ion distribution has an enhanced non-Maxwellian tail. (author). 19 refs, 4 figs, 1 tab

  5. Synthesis and catalytic properties of titanium containing extra-large pore zeolite CIT-5

    Czech Academy of Sciences Publication Activity Database

    Přech, Jan; Kubů, Martin; Čejka, Jiří

    2014-01-01

    Roč. 227, MAY 2014 (2014), s. 80-86. ISSN 0920-5861 R&D Projects: GA ČR GBP106/12/G015 Institutional support: RVO:61388955 Keywords : zeolite CIT-5 * titanosilicate * epoxidation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.893, year: 2014

  6. Effects of age and sex on 125I-β-CIT binding to DAT

    International Nuclear Information System (INIS)

    Objective: To investigate effects of age and sex on 125I-β-CIT binding to dopamine transporter (DAT). Methods: Detection of the differences in 125I-β-CIT binding kinetics in vivo between 6 week and 6 month old KM mice, and the differences of in vivo binding between female and male, and between 3 month and 12 month old SD rats.The animals were sacrificed 2 h after injection. Results: Uptake of 125I-β-CIT in the striatum, frontal cortex, parietal cortex, temporal cortex, occipital cortex, hippocampus, brain stem and whole brain in 6 week old mice was higher than that in 6 month old mice, and similar uptake pattern happened in between 3 month old and in 12 month old SD rats. In 12 months old SD rats, female rats had higher uptake in the striatum than male rats did. Conclusions: Young mice and rats have a higher uptake of 125I-β-CIT in the striatum than aged ones and female rats have a higher uptake than male ones do. This result indicates that the density of DAT in rat or mouse striatum may be reduced with aging

  7. Which Classroom Service Encounters Make Students Happy or Unhappy?: Insights from an Online CIT Study

    Science.gov (United States)

    Voss, Roediger; Gruber, Thorsten; Reppel, Alexander

    2010-01-01

    Purpose: This paper aims to explore satisfactory and dissatisfactory student-professor encounters in higher education from a student's perspective. The critical incident technique (CIT) is used to categorise positive and negative student-professor interactions and to reveal quality dimensions of professors. Design/methodology/approach: An…

  8. CIT, a gene involved in neurogenic cytokinesis, is mutated in human primary microcephaly.

    Science.gov (United States)

    Basit, Sulman; Al-Harbi, Khalid M; Alhijji, Sabri A M; Albalawi, Alia M; Alharby, Essa; Eldardear, Amr; Samman, Mohammed I

    2016-10-01

    Autosomal recessive primary microcephaly (MCPH) is a static neurodevelopmental disorder characterized by congenital small head circumference and non-progressive intellectual disability without additional severe brain malformations. MCPH is a genetically heterogeneous disorder. Sixteen genes (MCPH1-MCPH16) have been discovered so far, mutations thereof lead to autosomal recessive primary microcephaly. In a family, segregating MCPH in an autosomal recessive manner, genome-wide homozygosity mapping mapped a disease locus to 16.9-Mb region on chromosome 12q24.11-q24.32. Following this, exome sequencing in three affected individuals of the family discovered a splice site variant (c.753+3A>T) in citron kinase (CIT) gene, segregating with the disorder in the family. CIT co-localizes to the midbody ring during cytokinesis, and its loss of expression results in defects in neurogenic cytokinesis in both humans and mice. Splice site variant in CIT, identified in this study, is predicted to abolish splice donor site. cDNA sequence of an affected individual showed retention of an intron next to the splice donor site. The study, presented here, revealed the first variant in the CIT causing MCPH in the family. PMID:27519304

  9. Piezoelectrically Initiated Pyrotechnic Igniter

    Science.gov (United States)

    Quince, Asia; Dutton, Maureen; Hicks, Robert; Burnham, Karen

    2013-01-01

    This innovation consists of a pyrotechnic initiator and piezoelectric initiation system. The device will be capable of being initiated mechanically; resisting initiation by EMF, RF, and EMI (electromagnetic field, radio frequency, and electromagnetic interference, respectively); and initiating in water environments and space environments. Current devices of this nature are initiated by the mechanical action of a firing pin against a primer. Primers historically are prone to failure. These failures are commonly known as misfires or hang-fires. In many cases, the primer shows the dent where the firing pin struck the primer, but the primer failed to fire. In devices such as "T" handles, which are commonly used to initiate the blowout of canopies, loss of function of the device may result in loss of crew. In devices such as flares or smoke generators, failure can result in failure to spot a downed pilot. The piezoelectrically initiated ignition system consists of a pyrotechnic device that plugs into a mechanical system (activator), which on activation, generates a high-voltage spark. The activator, when released, will strike a stack of electrically linked piezo crystals, generating a high-voltage, low-amperage current that is then conducted to the pyro-initiator. Within the initiator, an electrode releases a spark that passes through a pyrotechnic first-fire mixture, causing it to combust. The combustion of the first-fire initiates a primary pyrotechnic or explosive powder. If used in a "T" handle, the primary would ramp the speed of burn up to the speed of sound, generating a shock wave that would cause a high explosive to go "high order." In a flare or smoke generator, the secondary would produce the heat necessary to ignite the pyrotechnic mixture. The piezo activator subsystem is redundant in that a second stack of crystals would be struck at the same time with the same activation force, doubling the probability of a first strike spark generation. If the first

  10. Fuir le récit pour raconter le quotidien. Modulations narratives en prose contemporaine

    Directory of Open Access Journals (Sweden)

    René Audet

    2007-08-01

    Full Text Available Dossier/Issue: 1 - Raconter le quotidien aujourd'hui - Si l’on désigne communément la pratique des récits du quotidien, cette étiquette recèle néanmoins quelque problème conceptuel, par la cohabitation d’une forme (le récit qui appelle la transgression de l’ordinaire à travers une temporalité et un objet (le quotidien qui se définit par ce caractère ordinaire. L’examen de trois cas, Enregistrements pirates de Ph. Delerm, Palomar d’I. Calvino et Étrange façon de vivre d’E. Vila-Matas, permettra de questionner la confusion habituelle entre récit et narrativité, d’établir comment l’arrimage est possible entre quotidien et narrativité, pour en venir à une réflexion sur les usages du narratif en littérature contemporaine.The expression "les récits du quotidien" (narratives of everyday life, although used quite frequently, actually conceals a theoretical problem concerning the cohabitation of a form (narrative based on the transgression of the ordinary through temporality and an object (everyday life which is itself defined by this ordinary quality. This study of three different works, Ph. Delerm’s Enregistrements pirates, I. Calvino’s Palomar, and E. Vila-Matas' Étrange façon de vivre, will try to shed some light on the confusion between "récit" and "narrativité" (narrative and narrativity, to better explain how narratives of everyday life do demonstrate narrativity, as well as how contemporary literature changes the uses of narrative.

  11. Fuir le récit pour raconter le quotidien. Modulations narratives en prose contemporaine

    Directory of Open Access Journals (Sweden)

    René Audet

    2007-06-01

    Full Text Available Si l’on désigne communément la pratique des récits du quotidien, cette étiquette recèle néanmoins quelque problème conceptuel, par la cohabitation d’une forme (le récit qui appelle la transgression de l’ordinaire à travers une temporalité et un objet (le quotidien qui se définit par ce caractère ordinaire. L’examen de trois cas, Enregistrements pirates de Ph. Delerm, Palomar d’I. Calvino et Étrange façon de vivre d’E. Vila-Matas, permettra de questionner la confusion habituelle entre récit et narrativité, d’établir comment l’arrimage est possible entre quotidien et narrativité, pour en venir à une réflexion sur les usages du narratif en littérature contemporaine. The expression "les récits du quotidien" (narratives of everyday life, although used quite frequently, actually conceals a theoretical problem concerning the cohabitation of a form (narrative based on the transgression of the ordinary through temporality and an object (everyday life which is itself defined by this ordinary quality. This study of three different works, Ph. Delerm’s Enregistrements pirates, I. Calvino’s Palomar, and E. Vila-Matas' Étrange façon de vivre, will try to shed some light on the confusion between "récit" and "narrativité" (narrative and narrativity, to better explain how narratives of everyday life do demonstrate narrativity, as well as how contemporary literature changes the uses of narrative.

  12. The National Ignition Facility

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF) is the largest construction project ever undertaken at Lawrence Livermore National Laboratory (LLNL). NIF consists of 192 forty-centimeter-square laser beams and a 10-m-diameter target chamber. NIF is being designed and built by an LLNL-led team from Los Alamos National Laboratory, Sandia National Laboratories, the University of Rochester, and LLNL. Physical construction began in 1997. The Laser and Target Area Building and the Optics Assembly Building were the first major construction activities, and despite several unforeseen obstacles, the buildings are now 92% complete and have been done on time and within cost. Prototype component development and testing has proceeded in parallel. Optics vendors have installed full-scale production lines and have done prototype production runs. The assembly and integration of the beampath infrastructure has been reconsidered and a new approach has been developed. This paper will discuss the status of the NIF project and the plans for completion. (author)

  13. Synthesis and quality control of 18F-β-FP-CIT as a dopamine transporter imaging agent

    International Nuclear Information System (INIS)

    Objective: To develop 18F-N-3-fluoropropyl-2-β-carbomethoxy-3-β-(4-iodophenyl) nortropane (18F-β-FP-CIT) as dopamine transporter imaging agent. Methods: The labelling of 18F-β-FP-CIT was performed via a two-step synthesis. The 18F-fluoropropyl bromide was prepared through a nucleophilic substitution by the use of the aminopolyether potassium complex (K/K222)+18F- as a phase-transfer reagent, and then by N-fluoroalkylation of 2-β-carbomethoxy-3-β-(4-iodophenyl) nortropane (nor-β-CIT) with 18F-fluoropropyl bromide the 18F-β-FP-CIT was formed. Contents and analytical methods of quality control for 18F-β-FP-CIT were investigated and the main quality criteria were achieved through strict control of the determining parameters by standard procedures. Results: The mean overall radiochemical yield from starting 18F-fluoride was about 8%, the total radiochemical synthesis time was about 90-110 min, and the radiochemical purity was better than 99% by HPLC and TLC. Tests on sterility and apyrogenicity of 18F-β-FP-CIT obtained by standard procedures were negative, and tests on other main quality criteria met the requirements of the local pharmacopoeia. Conclusion: 18F-β-FP-CIT injection can be used in the animal and human PET study

  14. Comparison of FP-CIT SPECT with F-DOPA PET in patients with de novo and advanced Parkinson's disease

    International Nuclear Information System (INIS)

    Diagnosis of Parkinson's disease (PD) can be difficult. F-DOPA PET is able to quantify striatal dopa decarboxylase activity and storage capacity of F-dopamine, but is expensive and not generally available. FP-CIT binds to the dopamine transporter, and FP-CIT SPECT is cheaper and more widely available, but has a lower resolution. The aim of this study was to compare these two methods in the same patients with different stages of PD to assess their power in demonstrating deficits of the striatal dopaminergic system. Thirteen patients with de novo PD and 17 patients with advanced PD underwent FP-CIT SPECT and static F-DOPA PET. After data transfer to standard stereotactic space, a template with regions of interest was used to sample values of the caudate, putamen and an occipital reference region. The outcome value was striato-occipital ratios. Patients were clinically examined in the ''off state'' (UPDRS-III and H and Y stage). Good correlations were found between striatal F-DOPA uptake and striatal FP-CIT uptake (r=0.78) and between putaminal F-DOPA uptake and putaminal FP-CIT uptake (r=0.84, both p<0.0001). Both striatal uptake of FP-CIT and that of F-DOPA correlated moderately with H and Y stage (ρ=-0.52 for both techniques), UPDRS-III (ρ=-0.38 for F-DOPA; ρ=-0.45 for FP-CIT) and disease duration (ρ=-0.59 for F-DOPA; ρ=-0.49 for FP-CIT, all p<0.05). FP-CIT values correlate well with F-DOPA values. Both methods correlate moderately with motor scores and are equally able to distinguish patients with advanced PD from patients with de novo PD. (orig.)

  15. Compact Stellarator Path to DEMO

    Science.gov (United States)

    Lyon, J. F.

    2007-11-01

    Issues for a DEMO reactor are sustaining an ignited/high-Q plasma in steady state, avoiding disruptions and large variations in power flux to the wall, adequate confinement of thermal plasma and alpha-particles, control of a burning plasma, particle and power handling, etc. Compact stellarators have key advantages -- steady-state high-plasma-density operation without external current drive or disruptions, stability without a close conducting wall or active feedback systems, and low recirculating power -- in addition to moderate plasma aspect ratio, good confinement, and high-beta potential. The ARIES-CS study established that compact stellarators can be competitive with tokamaks as reactors. Many of the issues for a compact stellarator DEMO can be answered using results from large tokamaks, ITER D-T experiments and fusion materials, technology and component development programs, in addition to stellarators in operation, under construction or in development. However, a large next-generation stellarator will be needed to address some physics issues: size scaling and confinement at higher parameters, burning plasma issues, and operation with a strongly radiative divertor. Technology issues include simpler coils, structure, and divertor fabrication, and better cost information.

  16. The National Ignition Facility Project

    International Nuclear Information System (INIS)

    The mission of the National Ignition Facility is to achieve ignition and gain in ICF targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effect testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule and costs associated with the construction project

  17. The Citrus transcription factor, CitERF13, regulates citric acid accumulation via a protein-protein interaction with the vacuolar proton pump, CitVHA-c4

    OpenAIRE

    Shao-jia Li; Xue-ren Yin; Xiu-lan Xie; Andrew C. Allan; Hang Ge; Shu-ling Shen; Kun-song Chen

    2016-01-01

    Organic acids are essential to fruit flavor. The vacuolar H+ transporting adenosine triphosphatase (V-ATPase) plays an important role in organic acid transport and accumulation. However, less is known of V-ATPase interacting proteins and their relationship with organic acid accumulation. The relationship between V-ATPase and citric acid was investigated, using the citrus tangerine varieties ‘Ordinary Ponkan (OPK)’ and an early maturing mutant ‘Zaoshu Ponkan (ZPK)’. Five V-ATPase genes (CitVHA...

  18. Alcohol ignition interlock programs.

    Science.gov (United States)

    Beirness, D J; Marques, P R

    2004-09-01

    The alcohol ignition interlock is an in-vehicle DWI control device that prevents a car from starting until the operator provides a breath alcohol concentration (BAC) test below a set level, usually .02% (20 mg/dl) to .04% (40 mg/dl). The first interlock program was begun as a pilot test in California 18 years ago; today all but a few US states, and Canadian provinces have interlock enabling legislation. Sweden has recently implemented a nationwide interlock program. Other nations of the European Union and as well as several Australian states are testing it on a small scale or through pilot research. This article describes the interlock device and reviews the development and current status of interlock programs including their public safety benefit and the public practice impediments to more widespread adoption of these DWI control devices. Included in this review are (1) a discussion of the technological breakthroughs and certification standards that gave rise to the design features of equipment that is in widespread use today; (2) a commentary on the growing level of adoption of interlocks by governments despite the judicial and legislative practices that prevent more widespread use of them; (3) a brief overview of the extant literature documenting a high degree of interlock efficacy while installed, and the rapid loss of their preventative effect on repeat DWI once they are removed from the vehicles; (4) a discussion of the representativeness of subjects in the current research studies; (5) a discussion of research innovations, including motivational intervention efforts that may extend the controlling effect of the interlock, and data mining research that has uncovered ways to use the stored interlock data record of BAC tests in order to predict high risk drivers; and (6) a discussion of communication barriers and conceptual rigidities that may be preventing the alcohol ignition interlock from taking a more prominent role in the arsenal of tools used to control

  19. National Ignition Facility: Experimental plan

    International Nuclear Information System (INIS)

    As part of the Conceptual Design Report (CDR) for the National Ignition Facility (NIF), scientists from Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), the University of Rochester's Laboratory for Laser Energetics (UR/LLE), and EG ampersand G formed an NIF Target Diagnostics Working Group. The purpose of the Target Diagnostics Working Group is to prepare conceptual designs of target diagnostics for inclusion in the facility CDR and to determine how these specifications impact the CDR. To accomplish this, a subgroup has directed its efforts at constructing an approximate experimental plan for the ignition campaign of the NIF CDR. The results of this effort are contained in this document, the Experimental Plan for achieving fusion ignition in the NIF. This group initially concentrated on the flow-down requirements of the experimental campaign leading to ignition, which will dominate the initial efforts of the NIF. It is envisaged, however, that before ignition, there will be parallel campaigns supporting weapons physics, weapons effects, and other research. This plan was developed by analyzing the sequence of activities required to finally fire the laser at the level of power and precision necessary to achieve the conditions of an ignition hohlraum target, and to then use our experience in activating and running Nova experiments to estimate the rate of completing these activities

  20. Fast Ignition Scheme Fusion Using High-Repetition-Rate Laser

    International Nuclear Information System (INIS)

    Full text: Using a high-repetition-rate laser for the first time, we have performed a compact fast ignition experiment to initiate a fusion reaction and to clarify its dynamics. A 4 J/0.4-ns output of an LD-pumped high-repetition laser HAMA is divided into the imploding and heating beams, which are illuminated on double deuterated polystyrene foils separated by 100 μm. The heating pulses heat the imploded core, emitting X-ray radiations and yielding 1000 thermal neutrons. Once heated, the core plasma maintains a temperature of few tens eV as long as the core stagnates. The result that the heating pulse transports its energy to the core plasma, is promising for promoting the fast ignition scheme laser fusion. (author)

  1. Compact toroid fueling for ITER

    International Nuclear Information System (INIS)

    Experimental and theoretical work indicates that deep fueling of ITER may be possible by Compact Toroid (CT) injection. CT velocities sufficient for center fueling of a reactor have been demonstrated in the RACE device. CT injections into the TdeV tokamak have achieved central penetration at 1.4 T, and have increased the particle inventory by more than 30% without disruption. Tests on the MARAUDER device have achieved CT mass-densities suitable for injection into 5 T tokamaks. Techniques for producing multiple-shot CT's with passive electric switching are being tested on CTIX. The advantages of deep fueling by CT injection include profile peaking to reach ignition, profile control, low tritium inventory and others. In this paper, the CT experimental results are summarized, a conceptual design of a CT fueler for ITER is presented, and the implications on ITER operation and fuel cycle are discussed. 16 refs., 2 figs., 1 tab

  2. The National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G H; Moses, E I; Wuest, C R

    2004-02-06

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter-diameter target chamber and room for 100 diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion and matter at extreme energy densities and pressures. NIF's energetic laser beams will compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will study physical processes at temperatures approaching 10{sup 8} K and 10{sup 11} bar; conditions that exist naturally only in the interior of stars and planets. NIF has completed the first phases of its laser commissioning program. The first four beams of NIF have generated 106 kilojoules in 23-ns pulses of infrared light and over 16 kJ in 3.5-ns pulses at the third harmonic (351 nm). NIF's target experimental systems are being commissioned and experiments have begun. This paper provides a detailed look the NIF laser systems, laser and optical performance, and results from recent laser commissioning shots. We follow this with a discussion of NIF's high-energy-density and inertial fusion experimental capabilities, the first experiments on NIF, and plans for future capabilities of this unique facility.

  3. Clinical features and 123I-FP-CIT SPECT imaging in drug-induced parkinsonism and Parkinson's disease

    International Nuclear Information System (INIS)

    To determine clinical predictors and accuracy of 123I-FP-CIT SPECT imaging in the differentiation of drug-induced parkinsonism (DIP) and Parkinson's disease (PD). Several clinical features and 123I-FP-CIT SPECT images in 32 patients with DIP, 25 patients with PD unmasked by antidopaminergic drugs (PDu) and 22 patients with PD without a previous history of antidopaminergic treatment (PDc) were retrospectively evaluated. DIP and PD shared all clinical features except symmetry of parkinsonian signs which was more frequently observed in patients with DIP (46.9%) than in patients with PDu (16.0%, p123I-FP-CIT SPECT images were normal in 29 patients with DIP (90.6%) and abnormal in all patients with PD, and this imaging technique showed high levels of accuracy. DIP and PD are difficult to differentiate based on clinical signs. The precision of clinical diagnosis could be reliably enhanced by 123I-FP-CIT SPECT imaging. (orig.)

  4. IGNITION AND FRONTIER SCIENCE ON THE NATIONAL IGNITION FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E

    2009-06-22

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF construction Project was certified by the Department of Energy as complete on March 30, 2009. NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. On March 10, 2009, a total 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader frontier scientific exploration. NIF experiments in support of indirect drive ignition will begin in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a 1.7 billion dollar national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes the science, technology, and equipment. Equipment required for ignition experiments include diagnostics, cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics (GA), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility and be ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility

  5. cit et interactivité : typologie des interactions narratives

    OpenAIRE

    Hurel, Pierre-Yves

    2013-01-01

    Cet article a pour objectif de produire une première typologie des éléments du récit qui prêtent aux interactions narratives ; concept défini ici comme reprenant les possibilités pour l'usager d'un récit interactif d'agir sur les développements de l'histoire. L'interactivité narrative y est développée en elle-même mais aussi au regard d'autres types d'interactions. Le tout se fait dans une problématique de l'engagement (en partie en opposition au concept de participation) de manière à situer ...

  6. "Rencontres de Genève - Histoire et Cité": building peace

    CERN Multimedia

    Laurianne Trimoulla

    2015-01-01

    How did people conceive, picture or imagine peace in former times? How did they contribute to it in concrete terms? Why and how were they sometimes obliged to fight to promote or enforce it? Which material, symbolic, financial, political and economic means were used to foster cohesion between societies, peoples and communities? The Rencontres de Genève - Histoire et Cité festival invites us to learn about the past to better understand the present.   Events taking place at Geneva University (Uni Dufour and Uni Bastions) and elsewhere in the city from Wednesday, 13 May to Saturday, 16 May. Organised by Geneva University’s Maison de l'histoire in collaboration with the Geneva Graduate Institute of International and Development Studies and the University of Applied Sciences and Arts of Western Switzerland (HES-SO), this first festival of history in Switzerland features a comprehensive programme of events taking place at various locations. The cit...

  7. A deficit scaling algorithm for the minimum flow problem

    Indian Academy of Sciences (India)

    Laura Ciupală

    2006-06-01

    In this paper, we develop a new preflow algorithm for the minimum flow problem, called deficit scaling algorithm. This is a special implementation of the generic preflow algorithm for the minimum flow problem developed by Ciurea and Ciupală earlier. The bottleneck operation in the generic preflow algorithm is the number of noncancelling pulls. Using the scaling technique (i.e. selecting the active nodes with sufficiently large deficits), we reduce the number of noncancelling pulls to $O(n^2 \\log \\bar{c})$ and obtain an $O(nm+n^2 \\log \\bar{c})$ algorithm.

  8. CERN’s job diversity on display at the Cité des Métiers

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    From 3 to 8 November, CERN took part in the Cité des Métiers careers fair in Geneva. Almost 10,000 people stopped by the Organization’s stand, where they were introduced to the wide range of professions practised at CERN.   Stefano Agosta, a telecommunications expert from the IT department, performs a geolocalisation demonstration with digital radio receivers for visitors to the CERN stand. Network engineering, computer graphics, geomatics, translation, video production, fire and rescue, law, computer-aided design… People often don’t realise how varied the job opportunities are at CERN. More than one hundred professions are present at the Laboratory. This was the message conveyed by representatives of various departments, including human resources and the visits service, at the CERN stand at the Cité des Métiers careers fair, from 3 to 8 November. CERN’s stand was part of the International Geneva section of the ...

  9. De l’ancre à l’encre. Navigations du récit

    OpenAIRE

    Jean VIVIÈS

    2014-01-01

    L’on m’apprend à écrireD’une étrange façonLa plume qu’on me donneA trente pieds de longL’encre ne manque pointCar l’encre, c’est la merLa plume c’est la rameQui m’apprend à voguer Cette strophe extraite de la « chansonnette » d’un étudiant venu de Cahors et condamné aux galères peu après la révocation de l’édit de Nantes en 1685 attire l’attention sur la mer comme l’encre du récit de voyage. C’est à des récits de voyage en mer et sur les fleuves que s’est attaché le colloque organisé par Sand...

  10. Functional analysis of the citrate activator CitO from Enterococcus faecalis implicates a divalent metal in ligand binding

    Directory of Open Access Journals (Sweden)

    Victor S. Blancato

    2016-02-01

    Full Text Available The regulator of citrate metabolism, CitO, from Enterococcus faecalis belongs to the FCD family within the GntR superfamily. In the presence of citrate, CitO binds to cis-acting sequences located upstream of the cit promoters inducing the expression of genes involved in citrate utilization. The quantification of the molecular binding affinities, performed by isothermal titration calorimetry (ITC, indicated that CitO has a high affinity for citrate (KD= 1.2±0.2 µM, while it did not recognize other metabolic intermediates. Based on a structural model of CitO where a putative small molecule and a metal binding site were identified, it was hypothesized that the metal ion is required for citrate binding. In agreement with this model, citrate binding to CitO sharply decreased when the protein was incubated with EDTA. This effect was reverted by the addition of Ni2+, and Zn2+ to a lesser extent. Structure-based site-directed mutagenesis was conducted and it was found that changes to alanine in residues Arg97 and His191 resulted in decreased binding affinities for citrate, as determined by EMSA and ITC. Further assays using lacZ fusions confirmed that these residues in CitO are involved in sensing citrate in vivo. These results indicate that the molecular modifications induced by a ligand and a metal binding in the C-terminal domain of CitO are required for optimal DNA binding activity, and consequently, transcriptional activation.

  11. The Ethylene Biosynthesis Gene CitACS4 Regulates Monoecy/Andromonoecy in Watermelon (Citrullus lanatus)

    Science.gov (United States)

    Manzano, Susana; Aguado, Encarnación; Martínez, Cecilia; Megías, Zoraida; García, Alicia; Jamilena, Manuel

    2016-01-01

    Monoecious and andromonoecious cultivars of watermelon are characterised by the production of male and female flower or male and hermaphrodite flowers, respectively. The segregation analysis in the offspring of crosses between monoecious and andromonoecious lines has demonstrated that this trait is controlled by a single gene pair, being the monoecious allele M semi-dominant to the andromonoecious allele A. The two studied F1 hybrids (MA) had a predominantly monoecious phenotype since both produced not only female flowers, but also bisexual flowers with incomplete stamens, and hermaphrodite flowers with pollen. Given that in other cucurbit species andromonoecy is conferred by mutations in the ethylene biosynthesis genes CmACS7, CsACS2 and CpACS27A we have cloned and characterised CitACS4, the watermelon gene showing the highest similarity with the formers. CitACS4 encoded for a type ACS type III enzyme that is predominantly expressed in pistillate flowers of watermelon. In the andromonoecious line we have detected a missense mutation in a very conserved residue of CitACS4 (C364W) that cosegregates with the andromonoecious phenotype in two independent F2 populations, concomitantly with a reduction in ethylene production in the floral buds that will develop as hermaphrodite flowers. The gene does not however co-segregates with other sex expression traits regulated by ethylene in this species, including pistillate flowering transition and the number of pistillate flowers per plant. These data indicate that CitAC4 is likely to be involved in the biosynthesis of the ethylene required for stamen arrest during the development of female flowers. The C364W mutation would reduce the production of ethylene in pistillate floral buds, promoting the conversion of female into hermaphrodite flowers, and therefore of monoecy into andromonoecy. PMID:27149159

  12. Differential diagnosis of Parkinsonism using dual phase F 18 FP CIT PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Jin, So Young; Oh, Min Young; Ok, Seung Jun; Oh, Jung Su; Lee, Sang Ju; Chung, Sun Ju; Lee, Chong Sik; Kim, Jae Seung [Univ. of Ulsan, Seoul (Korea, Republic of)

    2012-03-15

    Dopamine transporter (DAT) imaging can demonstrate presynaptic dopaminergic neuronal loss in Parkinson's disease (PD). However, differentiating atypical parkinsonism (APD) from PD is often difficult. We investigated the usefulness of dual phase F 18 FP CIT positron emission tomography (PET) imaging in the differential diagnosis of parkinsonism. Ninety eight subjects [five normal, seven drug induced parkinsonism (DIP), five essential tremor (ET), 24 PD, 20 multiple system atrophy parkinson type (MSA-P), 13 multiple system atrophy cerebellar type (MSA-C), 13 progressive supranuclear palsy (PSP), and 11 dementia with Lewy bodies(DLB)] underwent F 18 FP CIT PET. PET images were acquired at 5 min (early phase) and 3 h (late phase) after F 18 FP CIT administration (185MBq). Regional uptake pattern of cerebral and cerebellar hemispheres was assessed on early phase images, using visual, quantitative, and statistical parametric mapping (SPM) analyses. Striatal DAT binding was normal in normal, ET, DIP, and MSA C groups, but abnormal in PD, MSA P PSP, and DLB groups. No difference was found in regional uptake on early phase images among normal DAT binding groups, except in the MSA C group. Abnormal DAT binding groups showed different regional uptake pattern on early phase images compared with PD in SPM analysis (FDR<0.05). When discriminating APD from PD, visual interpretation of the early phase image showed high diagnostic sensitivity and specificity (75.4% and 100%, respectively). Regarding the ability to distinguish specific APD, sensitivities were 81% for MSA P, 77% for MSA C, 23% for PSP, and 54.5% for DLB. Dual phase F 18 FP CIT PET imaging is useful in demonstrating striatal DAT loss in neurodegenerative parkinsonism, and also in differentiating APD, particularly MSA, from PD.

  13. β-CIT SPECT demonstrates reduced availability of serotonin transporters in patients with fatal familial insomnia

    International Nuclear Information System (INIS)

    Fatal familial insomnia (FFI) is a rare hereditary human prion disease with unique clinical features including progressive sleep impairment and autonomic dysfunction. The serotonergic system is considered to be involved in the regulation of the sleep-wake cycle. In this study we demonstrate a reduced availability of serotonin transporters of 57 % and 73 % respectively in a thalamus-hypothalamus region of two FFI patients examined with β-CIT SPECT as compared to age-expected control values. (author)

  14. Differential diagnosis of Parkinsonism using dual phase F 18 FP CIT PET imaging

    International Nuclear Information System (INIS)

    Dopamine transporter (DAT) imaging can demonstrate presynaptic dopaminergic neuronal loss in Parkinson's disease (PD). However, differentiating atypical parkinsonism (APD) from PD is often difficult. We investigated the usefulness of dual phase F 18 FP CIT positron emission tomography (PET) imaging in the differential diagnosis of parkinsonism. Ninety eight subjects [five normal, seven drug induced parkinsonism (DIP), five essential tremor (ET), 24 PD, 20 multiple system atrophy parkinson type (MSA-P), 13 multiple system atrophy cerebellar type (MSA-C), 13 progressive supranuclear palsy (PSP), and 11 dementia with Lewy bodies(DLB)] underwent F 18 FP CIT PET. PET images were acquired at 5 min (early phase) and 3 h (late phase) after F 18 FP CIT administration (185MBq). Regional uptake pattern of cerebral and cerebellar hemispheres was assessed on early phase images, using visual, quantitative, and statistical parametric mapping (SPM) analyses. Striatal DAT binding was normal in normal, ET, DIP, and MSA C groups, but abnormal in PD, MSA P PSP, and DLB groups. No difference was found in regional uptake on early phase images among normal DAT binding groups, except in the MSA C group. Abnormal DAT binding groups showed different regional uptake pattern on early phase images compared with PD in SPM analysis (FDR<0.05). When discriminating APD from PD, visual interpretation of the early phase image showed high diagnostic sensitivity and specificity (75.4% and 100%, respectively). Regarding the ability to distinguish specific APD, sensitivities were 81% for MSA P, 77% for MSA C, 23% for PSP, and 54.5% for DLB. Dual phase F 18 FP CIT PET imaging is useful in demonstrating striatal DAT loss in neurodegenerative parkinsonism, and also in differentiating APD, particularly MSA, from PD

  15. Nitrogen assimilation in Citrus based on CitEST data mining

    OpenAIRE

    Ester Wickert; Jackson Marcondes; Manoel Victor Lemos; Lemos, Eliana G. M.

    2007-01-01

    Assimilation of nitrate and ammonium are vital procedures for plant development and growth. From these primary paths of inorganic nitrogen assimilation, this metabolism integrates diverse paths for biosynthesis of macromolecules, such as amino acids and nucleotides, and the central intermediate metabolism, like carbon metabolism and photorespiration. This paper reports research performed in the CitEST (Citrus Expressed Sequence Tag) database for the main genes involved in nitrogen metabolism ...

  16. Toxicity, mutagenicity, and behavioral effects of β-CIT, a ligand for dopamine transporter exploration by SPECT

    International Nuclear Information System (INIS)

    The cocaine analog β-CIT is one of the most used compounds for SPET examination of the dopamine transporter in drug abuse and Parkinson's disease. However, the toxicity of this agent has not yet been studied. We report here acute toxicity, mutagenicity, and effect on locomotor activity of β-CIT. Acute toxicity experiments were performed in mice and rats. The LD50 values were about 20 mg and 5 mg for mice and rats, respectively. There was no sex difference. The mutagenicity was evaluated using the Ames' test. No mutagenic effect was observed for β-CIT. Effects on locomotor activity were measured in mice using the open-field test. β-CIT increased locomotion (+65%) when injected at a dose of 0.312 mg/kg; the maximal increase (+205%) was observed at a dose of 1.25 mg/kg; at higher doses, the effect was decreased slightly. These pharmacological findings are in agreement with an inhibitory effect of β-CIT at the dopamine transporter. We conclude that with no mutagenic effects and LD50 more than 6 orders of magnitude higher than the routinely used doses in PET or SPET, it can be assumed that β-CIT can be safely used as a radioligand in humans

  17. Clinical Significance of F 18 FP CIT Dual Time Point PET Imaging in Idiopathic Parkinson's Disease

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the diagnostic value of dual time point F 18 FP CIT PET imaging in idiopathic Parkinson's disease (PD). Twenty four patients with PD (mean age 69.6) and 18 healthy people (mean age 70.26) underwent two sequential PET/CT scans (dual time point imaging) at 90 and 210 min after F 18 FP CIT injection. Tracer activity of region of interest was measured in the caudate, putamen and a reference region in the brain from both time points. The outcome parameter was the striatooccipital ratio (SOR). Normal SOR values were obtained in the control group. The percent change in tracer activity between 90 and 210 min images was calculated. The SOR values and the percent change in tracer activity were compared between the patients and healthy control group. The SOR values for the caudate, anterior and posterior putamen at both 90 and 210 min images were significantly reduced in the patients with PD. The lowest P value was obtained for the anterior and posterior putamen (p<0.001) at both time points. There were significant differences of the percent change in tracer activity for the anterior and posterior putamen in the two groups (p=0.01) F 18 FP CIT PET scans at 90 and 210 min after injection are both able to diagnose PD. Therefore, the 90 min image by itself in sufficient for diagnosing PD.

  18. (123I)β-CIT and SPECT in essential tremor and Parkinson's disease

    International Nuclear Information System (INIS)

    Resting and postural tremor may occur in essential tremor (ET) and Parkinson's disease (PD). The aim of the present study was to investigate the cocaine derivative [123I] β-CIT, which labels striatal dopamine transporters, and SPECT in differentiating these diseases. Methods: 30 healthy volunteers, 32 patients with ET and 29 patients with idiopathic PD of Hoehn/Yahr stage I were investigated. Specific over nondisplaceable binding ratios (target/cerebellum-1) were calculated for the striatum, the caudate nucleus and the putamen separately as well as a ratio putamen/caudate and the percent deviation of each patient's ratio from ageexpected control values. Results: striatal (123I]β-CIT binding ratios in ET were within normal ranges and showed only a discrete elevation to age-expected control values (+ 14.6 %). In PD significantly reduced specific binding was evident not only contralaterally to the clinically affected side (putamen: - 62 %, caudate nucleus: - 35 %), but also ipsilaterally (putamen: - 45 %, caudate nucleus: - 22 %). All investigated parameters differed significantly between PD and controls and ET respectively. Conclusion: imaging striatal dopamine transporters with (123I)β-CIT and SPECT could clearly distinguish between ET and PD in an early stage of the disease. Findings do not suggest a subclinical involvement of dopaminergic nigrostriatal neurons in ET. (author)

  19. Multimodal Friction Ignition Tester

    Science.gov (United States)

    Davis, Eddie; Howard, Bill; Herald, Stephen

    2009-01-01

    The multimodal friction ignition tester (MFIT) is a testbed for experiments on the thermal and mechanical effects of friction on material specimens in pressurized, oxygen-rich atmospheres. In simplest terms, a test involves recording sensory data while rubbing two specimens against each other at a controlled normal force, with either a random stroke or a sinusoidal stroke having controlled amplitude and frequency. The term multimodal in the full name of the apparatus refers to a capability for imposing any combination of widely ranging values of the atmospheric pressure, atmospheric oxygen content, stroke length, stroke frequency, and normal force. The MFIT was designed especially for studying the tendency toward heating and combustion of nonmetallic composite materials and the fretting of metals subjected to dynamic (vibrational) friction forces in the presence of liquid oxygen or pressurized gaseous oxygen test conditions approximating conditions expected to be encountered in proposed composite material oxygen tanks aboard aircraft and spacecraft in flight. The MFIT includes a stainless-steel pressure vessel capable of retaining the required test atmosphere. Mounted atop the vessel is a pneumatic cylinder containing a piston for exerting the specified normal force between the two specimens. Through a shaft seal, the piston shaft extends downward into the vessel. One of the specimens is mounted on a block, denoted the pressure block, at the lower end of the piston shaft. This specimen is pressed down against the other specimen, which is mounted in a recess in another block, denoted the slip block, that can be moved horizontally but not vertically. The slip block is driven in reciprocating horizontal motion by an electrodynamic vibration exciter outside the pressure vessel. The armature of the electrodynamic exciter is connected to the slip block via a horizontal shaft that extends into the pressure vessel via a second shaft seal. The reciprocating horizontal

  20. SCB thermite igniter studies

    Energy Technology Data Exchange (ETDEWEB)

    Bickes, R.W. Jr.; Wackerbarth, D.E. [Sandia National Labs., Albuquerque, NM (United States); Mohler, J.H. [Energetic Materials Associates, Inc., Vero Beach, FL (United States)

    1996-12-31

    The authors report on recent studies comparing the ignition threshold of temperature cycled, SCB thermite devices with units that were not submitted to temperature cycling. Aluminum/copper-oxide thermite was pressed into units at two densities, 45% of theoretical maximum density (TMD) or 47% of TMD. Half of each of the density sets underwent three thermal cycles; each cycle consisted of 2 hours at 74 C and 2 hours at {minus}54 C, with a 5 minute maximum transfer time between temperatures. The temperature cycled units were brought to ambient temperature before the threshold testing. Both the density and the thermal cycling affected the all-fire voltage. Using a 5.34 {micro}F CDU (capacitor discharge unit) firing set, the all-fire voltage for the units that were not temperature cycled increased with density from 32.99 V (45% TMD) to 39.32 V (47% TMD). The all-fire voltages for the thermally cycled units were 34.42 V (45% TMD) and 58.1 V (47% TMD). They also report on no-fire levels at ambient temperature for two component designs; the 5 minute no-fire levels were greater than 1.2 A. Units were also subjected to tests in which 1 W of RF power was injected into the bridges at 10 MHz for 5 minutes. The units survived and fired normally afterwards. Finally, units were subjected to pin-to-pin electrostatic discharge (ESD) tests. None of the units fired upon application of the ESD pulse, and all of the tested units fired normally afterwards.

  1. Compact Reactor

    International Nuclear Information System (INIS)

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date

  2. Thermonuclear Ignition of Dark Galaxies

    CERN Document Server

    Herndon, J M

    2006-01-01

    Dark matter is thought to be at least an order of magnitude more abundant than luminous matter in the Universe, but there has yet to be an unambiguous identification of a wholly dark, galactic-scale structure. There is, however, increasing evidence that VIRGOHI 21 may be a dark galaxy. If VIRGOHI 21 turns out to be composed of dark stars, having approximately the same mass of stars found in luminous galaxies, it will pose an enigma within the framework of current astrophysical models, but will provide strong support for my concept, published in 1994 in the Proceedings of the Royal Society of London, of the thermonuclear ignition of stars by nuclear fission, and the corollary, non-ignition of stars. The possibility of galactic thermonuclear ignition is discussed from that framework and leads to my suggestion that the distribution of luminous stars in a galaxy may simply be a reflection of the galactic distribution of the heavy elements.

  3. SPECT 123-I-[FP-CIT] diagnostic in the presynaptic parkinsonism

    International Nuclear Information System (INIS)

    Detection of loss off functional dopaminergic neurone terminals in the striatum of patients with clinically uncertain Parkinsonian Syndromes will help to differentiate the Essential Tremor (ET) from the Parkinson Syndromes related to idiopathic Parkinson's Disease (PD), Multiple System Atrophy (MSA) or Progressive Supranuclear Palsy (PSP). In these cases dopaminic medication should be avoided for patients not suffering from true parkinsonism.Objective of the study is to determine the utility of [123I] FP-CIT SPECT in clinically uncertain Parkinsonian syndromes and their differentiation from ET. Materials and Methods: This prospective study involved 9 patients (4 males and 5 females, aged between 38 - 81 years) with clinically uncertain Parkinsonism. The main symptoms were tremor (n=8), gait alteration (n=6), bradykinesia (n=3) and Negro phenomena positive (n=2), or a combination of these symptoms (n=9), with subsequent follow-up of 7-8 months. Dopamine agonists and antagonists acting on the postsynaptic dopamine receptors were not accepted to interfere with 123I-Ioflupane. All patients underwent appropriate thyroid blocking by oral administration of 120 mg potassium iodide before and after [123] I FP-CIT application. All patents underwent SPECT scans 3-4 hours after i.v. injection of 185 MBq [123] FP-CIT (DaTSCAN - Amersham) on a Diacam Gamma-Camera System (Siemens). To estimate [123] FP-CIT biodistribution whole-body scans were performed, 15 minutes and 2-3 hrs after the i.v. application of the tracer. The SPECT results were evaluated visually and semi quantitatively. The [123] FP-CIT uptake of the striatum (nucleus caudatus and putamen) was referenced to the occipital cortex and to the symmetrical ROI. The scanning procedure was completed according to strict conditions for symmetry and geometry. The filtering and reconstructing procedures if the images were performed individually for each patient to avoid artifacts and errors. In all patients CT scans were normal

  4. PITR: Princeton Ignition Test Reactor

    International Nuclear Information System (INIS)

    The principal objectives of the PITR - Princeton Ignition Test Reactor - are to demonstrate the attainment of thermonuclear ignition in deuterium-tritium, and to develop optimal start-up techniques for plasma heating and current induction, in order to determine the most favorable means of reducing the size and cost of tokamak power reactors. This report describes the status of the plasma and engineering design features of the PITR. The PITR geometry is chosen to provide the highest MHD-stable values of beta in a D-shaped plasma, as well as ease of access for remote handling and neutral-beam injection

  5. Flow Friction or Spontaneous Ignition?

    Science.gov (United States)

    Stoltzfus, Joel M.; Gallus, Timothy D.; Sparks, Kyle

    2012-01-01

    "Flow friction," a proposed ignition mechanism in oxygen systems, has proved elusive in attempts at experimental verification. In this paper, the literature regarding flow friction is reviewed and the experimental verification attempts are briefly discussed. Another ignition mechanism, a form of spontaneous combustion, is proposed as an explanation for at least some of the fire events that have been attributed to flow friction in the literature. In addition, the results of a failure analysis performed at NASA Johnson Space Center White Sands Test Facility are presented, and the observations indicate that spontaneous combustion was the most likely cause of the fire in this 2000 psig (14 MPa) oxygen-enriched system.

  6. PITR: Princeton Ignition Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    The principal objectives of the PITR - Princeton Ignition Test Reactor - are to demonstrate the attainment of thermonuclear ignition in deuterium-tritium, and to develop optimal start-up techniques for plasma heating and current induction, in order to determine the most favorable means of reducing the size and cost of tokamak power reactors. This report describes the status of the plasma and engineering design features of the PITR. The PITR geometry is chosen to provide the highest MHD-stable values of beta in a D-shaped plasma, as well as ease of access for remote handling and neutral-beam injection.

  7. 75 FR 47520 - Standards of Performance for Stationary Compression Ignition and Spark Ignition Internal...

    Science.gov (United States)

    2010-08-06

    ... rulemaking published in the Federal Register on June 8, 2010 (75 FR 32612). That notice proposed revisions to... Compression Ignition and Spark Ignition Internal Combustion Engines AGENCY: Environmental Protection Agency... the standards of performance for stationary compression ignition and spark ignition...

  8. The national ignition facility: path to ignition in the laboratory

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF) is a 192-beam laser facility presently under construction at Lawrence Livermore National Laboratory. When completed, NIF will be a 1.8-MJ, 500-TW ultraviolet laser system. Its missions are to obtain fusion ignition of deuterium-tritium plasmas in ICF (Inertial Confinement Fusion) targets and to perform high energy density experiments in support of the U.S. nuclear weapons stockpile. The NIF facility will consist of 2 laser bays, 4 capacitor areas, 2 laser switchyards, the target area and the building core. The laser is configured in 4 clusters of 48 beams, 2 in each laser bay. Four of the NIF beams have been already commissioned to demonstrate laser performance and to commission the target area including target and beam alignment and laser timing. During this time, NIF has demonstrated on a single-beam basis that it will meet its performance goals and has demonstrated its precision and flexibility for pulse shaping, pointing, timing and beam conditioning. It also performed 4 important experiments for ICF and High Energy Density Science. Presently, the project is installing production hardware to complete the project in 2009 with the goal to begin ignition experiments in 2010. An integrated plan has been developed including the NIF operations, user equipment such as diagnostics and cryogenic target capability, and experiments and calculations to meet this goal. This talk will provide NIF status, the plan to complete NIF, and the path to ignition. (authors)

  9. Confinement of ignition and yield on the National Ignition Facility

    International Nuclear Information System (INIS)

    The National Ignition Facility Target Areas and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented

  10. Büroo Ignite = Ignite office / Priit Põldme, Reet Sepp

    Index Scriptorium Estoniae

    Põldme, Priit, 1971-

    2013-01-01

    Büroo Ignite (Tatari 25, Tallinn) sisekujundusest. Sisearhitektid Priit Põldme ja Reet Sepp (SAB Joonprojekt). Arhitektid Heiki Taras ja Ahti Luhaäär (Arhitektibüroo Pilter ja Taras). Sisearhitekti ja ESLi aastapreemiate žürii esimehe Kaido Kivi arvamus

  11. Confinement of ignition and yield on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, M.; Karpenko, V.; Foley, D.; Anderson, A.; Burnham, A.; Reitz, T.; Latkowski, J.; Bernat, T.

    1996-06-14

    The National Ignition Facility Target Areas and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented.

  12. Effect of age and gender on dopamine transporter imaging with [123I]FP-CIT SPET in healthy volunteers

    International Nuclear Information System (INIS)

    Dopamine transporter imaging is a valuable tool to investigate the integrity of the dopaminergic neurons. To date, several reports have shown an age-associated decline in dopamine transporters in healthy volunteers. Although animal studies suggest an effect of gender on dopamine transporter density, this gender effect has not yet been confirmed in human studies. To study the influence of age and gender on dopamine transporter imaging in healthy volunteers, we performed single-photon emission tomography imaging with [123I]FP-CIT to quantify dopamine transporters. Forty-five healthy volunteers (23 males and 22 females) were included, ranging in age from 18 to 83 years. SPET imaging was performed 3 h after injection of ±110 MBq [123I]FP-CIT. An operator-independent volume of interest analysis was used for quantification of [123I]FP-CIT binding in the striatum. The ratio of specific striatal to non-specific [123I]FP-CIT binding was found to decrease significantly with age. Moreover, we found a high variance in [123I]FP-CIT binding in young adults. Finally, females were found to have significantly higher [123I]FP-CIT binding ratios than males. This effect of gender on [123I]FP-CIT binding ratios was not related to age. The results of this study are consistent with findings from previous studies, which showed that dopamine transporter density declines with age. The intriguing finding of a higher dopamine transporter density in females than in males is in line with findings from animal studies. (orig.)

  13. Direct comparison of FP-CIT SPECT and F-DOPA PET in patients with Parkinson's disease and healthy controls

    International Nuclear Information System (INIS)

    Diagnosing Parkinson's disease (PD) on clinical grounds may be difficult, especially in the early stages of the disease. F-DOPA PET and FP-CIT SPECT scans are able to determine presynaptic dopaminergic activity in different ways. The aim of this study was to determine and compare the sensitivity and specificity of the two methods in the detection of striatal dopaminergic deficits in the same cohort of PD patients and healthy controls. Movement disorder specialists recruited 11 patients with early-stage PD and 17 patients with advanced PD. The patients underwent both an FP-CIT SPECT scan and an F-DOPA PET scan. In addition, 10 FP-CIT SPECT scans or 10 F-DOPA PET scans were performed in 20 healthy controls. A template with regions of interest was used to sample tracer activity of the caudate, putamen and a reference region in the brain. The outcome parameter was the striatooccipital ratio (SOR). Normal SOR values were determined in the controls. The sensitivity and specificity of both scanning methods were calculated. FP-CIT SPECT and F-DOPA PET scans were both able to discriminate PD patients from healthy controls. For the early phases of the disease, sensitivity and specificity of the contralateral striatal and putaminal uptake of FP-CIT and F-DOPA was 100%. When only caudate uptake was considered, the specificities were 100% and 90% for FP-CIT and F-DOPA, respectively, while the sensitivity was 91% for both scanning techniques. FP-CIT SPECT and F-DOPA PET scans are both able to diagnose presynaptic dopaminergic deficits in early phases of PD with excellent sensitivity and specificity. (orig.)

  14. cits d'îles. Espace insulaire et poétique du récit dans l'Estoire del saint Graal

    OpenAIRE

    Séguy, Mireille

    2006-01-01

    L'Estoire del saint Graal constitue le premier volet du cycle romanesque du Lancelot-Graal. En tant que tel, ce récit doit fixer les débuts de la trajectoire du Graal, ménager des liens entre l'Antiquité païenne et les temps arthuriens, mais aussi assurer autant que faire se peut la cohésion d'un immense ensemble constitué de massifs narratifs hétérogènes. Ce difficile « cahier des charges » est compliqué du fait que l'Estoire a certainement été composée après l'ensemble du cycle dont elle do...

  15. Integral low-energy thermite igniter

    Science.gov (United States)

    Gibson, Albert; Haws, Lowell D.; Mohler, Jonathan H.

    1984-08-14

    In a thermite igniter/heat source comprising a container holding an internal igniter load, there is provided the improvement wherein the container consists essentially of consumable consolidated thermite having a low gas output upon combustion, whereby upon ignition, substantially all of the container and said load is consumed with low gas production.

  16. Pyrotechnic Igniters for Liquid Propellant Gun .

    OpenAIRE

    D. K. Kharat; K. J. Daniel; K. R. Rao; A. A. Ghosh; Shah, S.T.; S. C. Mitra

    1997-01-01

    The results of a preliminary investigation on the use of liquid propellant for gun application are presented. Both regenerative and bulk loaded liquid propellant guns were used in the study.Pyrotechnic igniters were tried out for igniting the liquid propellant. Existing pyrotechnic igniters were suitably modified to obtain pressure beyond 20 MPa in less than 3 ms in the combustion chamber.

  17. Plasma ignition of LOVA propellants

    NARCIS (Netherlands)

    Driel, C.A. van; Boluijt, A.G.; Schilt, A.

    2010-01-01

    Ignition experiments were performed using a gun simulator which is equipped with a burst disk. This equipment facilitates the application of propellant loading densities which are comparable to those applied in regular ammunitions. For this study the gun simulator was equipped with a plasma jet igni

  18. A comparative study on 67Ga-Cit imaging and CT or MRI in diagnosis of maxillofacial neoplasms

    International Nuclear Information System (INIS)

    Objective: To evaluate the clinical value of 67ga-Citrate (Cit) imaging and CT or MRI in diagnosis of maxillofacial neoplasms. Methods: Before surgery, 71 patients with maxillofacial neoplasms were studied with 67Ga-Cit imaging and CT or MRI. All results were compared with pathological findings. Results: 1) In 36 patients with benign maxillofacial mass, 28 cases were with negative 67Ga-Cit imaging (77.8%, 28/36), whereas 8 cases with positive results (22.2%, 8/36); in 35 patients with malignant tumors, 33 cases with positive 67Ca-Cit imaging (94.3%, 33/35), whereas 2 cases with negative results( 5.7%, 2/35). 2) For CT or MRI, in 24 patients with benign maxillofacial mass, only 4 cases were found in concordance with pathological findings (16.7%, 4/24), but in 24 patients with malignant maxillofacial tumors, 6 cases were found in concordance with pathological findings (25.0%, 6/24). In the differentiating malignant maxillofacial tumors from benign ones, there was significant difference in accuracy between these modalities (x2 = 21.60, 19.91, both were P 2 = 1.28, 0.26 and 1.76, respectively, all were P > 0.05). Conclusion: The accuracy of 67Ga-Cit imaging in differentiating malignant maxillofacial tumors from benign ones is significantly higher than that of CT or MRI

  19. Enhancement of [123I[β-CIT binding in the striatum with clomipramine: is there a serotonin-dopamine interaction?

    International Nuclear Information System (INIS)

    Many reports support the concept of serotonergic-dopaminergic interaction in the brain. However, at present, there are few methods to study this relationship in vivo. The purpose of this study was to investigate the effect of serotonin (5-HT) uptake inhibitor, clomipramine, on a dopamine (DA) transporter ligand, [123I[β-CIT (RTI-55), in rat brain. Dose-dependent changes in [123I[β-CIT specific binding induced by clomipramine were studied in the striatum (rich in DA transporter) and the hypothalamus (rich in 5-HT transporter). The changes in the time-activity curves of [123I[β-CIT specific binding after clomipramine injection were also examined in these two regions. Using the cerebellum as the reference region, k3and k 4values with and without clomipramine administration were estimated by a two-compartment kinetic analysis. Clomipramine inhibited [123I[β-CIT specific binding in the hypothalamus, but enhanced its specific binding in the striatum in a dose-dependent manner. Kinetic analysis showed that k 3in the striatum was increased by 55%. In conclusion, enhancement of [123I[fbeta-CIT binding in the striatum after clomipramine administration indicated the possibility of 5-HT-DA interaction. (orig.). With 3 figs., 1 tab

  20. Laser ignition application in a space experiment

    Science.gov (United States)

    Liou, Larry C.; Culley, Dennis E.

    1993-01-01

    A laser ignition system is proposed for the Combustion Experiment Module on an orbiting spacecraft. The results of a design study are given using the scheduled 'Flame Ball Experiment' as the design guidelines. Three laser ignition mechanisms and wavelengths are evaluated. A prototype laser is chosen and its specifications are given, followed by consideration of the beam optical arrangement, the ignition power requirement, the laser ignition system weight, size, reliability, and laser cooling and power consumption. Electromagnetic interference to the onboard electronics caused by the laser ignition process is discussed. Finally, ground tests are suggested.

  1. Research of laser ignition detection system

    Science.gov (United States)

    Yang, Feng; Zhao, Dong; Xu, Qie; Ai, Xin

    2010-10-01

    Laser ignition is an important means of detonation but the accuracy and security is requested strictly. Based on the above, two points were considered in the design: achieve ignition-Fiber-optical health monitoring in the condition of low-intensity light (ensure the safety of gunpowder); observant the explosive imaging. In the paper, the laser ignition equipment was designed with optical detection and inner optical imaging system for the real-time monitoring to the optical fiber and the process of ignition. This design greatly improved the reliability and the safety of laser ignition system and provided the guarantee for usage and industrialization.

  2. Desensitizing nano powders to electrostatic discharge ignition

    Energy Technology Data Exchange (ETDEWEB)

    Steelman, Ryan [Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering; Clark, Billy [Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering; Pantoya, Michelle L. [Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering; Heaps, Ronald J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Daniels, Michael A. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

  3. Trajets quotidiens et récits délinquants

    Directory of Open Access Journals (Sweden)

    Michael Sheringham

    2007-06-01

    Full Text Available Si l’expérience de la quotidienneté, qui préoccupe un philosophe comme Henri Lefebvre ou un écrivain comme Georges Perec, semble résister à l’emprise du roman, Michel de Certeau a pu mettre une réflexion sur le récit au cœur de son essai fondamental, L’invention du quotidien. En effet, les notions de « récits délinquants » ou d’« énonciations piétonnières », chez Certeau, fournissent des outils précieux pour l’élucidation du rôle du récit dans des textes qui interrogent le monde quotidien à partir de pérégrinations et de méditations urbaines, dont certains exemples majeurs sont traités ici : Un ethnologue dans le métro (Marc Augé, Journal du dehors (Annie Ernaux, Les passagers du Roissy-Express (François Maspero, La liberté des rues (Jacques Réda. If the experience of everydayness, which preoccupied a philosopher like Henri Lefebvre and a writer like Georges Perec, seem to resist the sway of the novel, Michel de Certeau nonetheless placed a consideration of narrative at the heart of his seminal essay Practices of Everyday Life. And indeed such notions as "delinquent narratives" and "pedestrian speech acts", elaborated by Certeau, provide precious tools for identifying the role of narrative in texts which interrogate the everyday world on the basis of urban peregrinations and meditations, of which some major examples are examined here : An Ethnologist in the Metro (Marc Augé, Exteriors (Annie Ernaux, Roissy-Express : A Journey Through the Paris Suburbs (François Maspero, The Freedom of the Streets (Jacques Réda.

  4. Measurement of the dopaminergic degeneration in Parkinson's disease with [123I]β-CIT and SPECT

    International Nuclear Information System (INIS)

    The cocaine derivative [123I]β-CIT binds with high affinity to dopamine uptake sites in the striatum and can be used to visualize dopaminergic nerve terminals in vivo in the human brain with SPECT. It has been validated that the calculation of a simple ratio of specific/non-displaceable binding during a period of binding-equilibrium in the striatum about 20 hrs after bolus injection of the tracer gives a strong and reliable index of the binding potential of dopamine uptake sites. Our own results in a group of 113 patients with PD demonstrate a 45 % loss of striatal [123I]β-CIT binding in comparison to age corrected control values. Highly significant correlations of SPECT findings with clinical data obtained from the UPDRS rating scale such as akinesia, rigidity, axial symptoms and activities of daily living are demonstrated, while no correlation is found with tremor. The signal loss in a region comprising the whole striatum ranges from 35 % in Hoehn/Yahr stage I to over 72 % in stage V and is highly significantly correlated to the different stages of disease severity. Data in 9 patients with multiple system atrophy (MSA) and 4 patients with progressive supranuclear palsy (PSP) are similar to the findings in PD although the differences between caudate and putamen are somewhat less marked. These data demonstrate that the dopaminergic nerve cell loss in PD and other disorders with a dopaminergic lesion can be quantified with [123I]β-CIT and SPECT and that hopefully a preclinical or very early diagnosis is made possible. Such studies might also open the way for a better evaluation of neuroprotective strategies in PD. It does not seem to be possible however to differentiate PD and MSA or PSP with this method in individual cases. (author)

  5. L’ambivalence du récit de guerre : Mugi to heitai de Hino Ashihei, de l’expérience individuelle au récit commun

    OpenAIRE

    Muller, Guillaume

    2014-01-01

    Mugi to heitai, le premier récit de guerre de Hino Ashihei, est le lieu d’une tension entre deux perspectives a priori opposées, puisqu’il est à la fois récit individuel et récit d’une expérience commune. Sous la forme d’un journal, le texte surinvestit les codes de l’écriture personnelle pour mieux affirmer la crédibilité et l’authenticité du propos ; la valeur revendiquée de cette voix peut cependant être mise au jour au moyen d’approches complémentaires de la notion de porte-parole. Les je...

  6. Cristine de Pizan e le emozioni per la Cità des Dames

    OpenAIRE

    Angela Giallongo

    2011-01-01

    L’interesse storico per le emozioni spinge ad interrogarsi sul loro ruolo nelle utopie femminili alla fine del medioevo. Una fonte centrale su questo tema è l’opera illustrata la Cité des Dames (1405) di C. de Pizan (1365-1430). Gli studi di B.H. Rosenwein, W. Reddie e K.Oatley forniscono categorie interpretative psico-sociali (comunità emotive e regime emotivo) utili per connettere l’idea di utopia, valori emotivi e rapporti interpersonali fra i sessi. La problematicizzazione, suggerita da R...

  7. Ghost-Buzz'ers - Den alternative lanceringskampagne for Ghosts of Cité Soleil

    OpenAIRE

    Christensen, Anders Sommer; Dudas-Schwarz, Daniel; Daniel, Tafdrup; Jensen, Mathis Eskjær; Bech, Morten Deleuran

    2007-01-01

    The report concerns itself with the alternative marketing campaign for the documentary Ghosts of Cité Soleil. It takes place in the Spring of 2007 and is developed by the Ghost-group in cooperation with Nordisk Film A/S. The purpose of the campaign is to create a buzz about the movie and initiate its viral spread like a virus through the network of the target group. The primary target group is defined as 18 to 22-years-old Copenhageners with an interest in hip-hop, which has de...

  8. Prepulse inhibition is associated with attention, processing speed, and 123I-FP-CIT SPECT in Parkinson's disease

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Biernat, Heidi B; Nikolic, Miki; Korbo, Lise; Friberg, Lars; Jennum, Poul J

    2014-01-01

    's disease have been extensively studied in relation to motor function, less is known about the potential role of sensorimotor processes in cognitive function. OBJECTIVE: We investigated the relationship between prepulse inhibition, cognition and nigrostriatal dysfunction, as measured with 123I-FP......-CIT-SPECT scanning, in patients with Parkinson's disease. METHODS: 38 Parkinson patients were assessed with prepulse inhibition, neuropsychological tests, and neurological investigation. A subset of these patients underwent 123I-FP-CIT-SPECT scanning. RESULTS: Patients with a higher level of prepulse inhibition...... performed better on cognitive measures tapping attention and processing speed than patients with a lower level of prepulse inhibition. Furthermore, there were significant correlations between prepulse inhibition and 123I-FP-CIT uptake in the striatum. CONCLUSIONS: Our results suggest that the level of...

  9. Evaluation of [123I]β-CIT binding with spect in controls, early and late Parkinson's disease

    International Nuclear Information System (INIS)

    The main neuropathological feature in Parkinson's disease (PD) is a severe degeneration of the dopaminergic neurons in the substantia nigra resulting in a loss of dopamine in the striatum. Recently, a new radioligand (β-CIT) for single photon emission computed tomography (SPECT) became available for in vivo imaging of the dopamine transporter on nerve endings of dopaminergic neurons in the striatum. The present results demonstrate that [123I]-β-CIT SPECT allows a discrimination between early and late PD patients. In our opinion, these preliminary data suggest that [123I]-β-CIT SPECT should be used from now on in longitudinal studies (such as the DATATOP study) in which the effects of (putative) neuroprotective interventions in PD are monitored

  10. Tritium and ignition target management at the National Ignition Facility.

    Science.gov (United States)

    Draggoo, Vaughn

    2013-06-01

    Isotopic mixtures of hydrogen constitute the basic fuel for fusion targets of the National Ignition Facility (NIF). A typical NIF fusion target shot requires approximately 0.5 mmoles of hydrogen gas and as much as 750 GBq (20 Ci) of 3H. Isotopic mix ratios are specified according to the experimental shot/test plan and the associated test objectives. The hydrogen isotopic concentrations, absolute amounts, gas purity, configuration of the target, and the physical configuration of the NIF facility are all parameters and conditions that must be managed to ensure the quality and safety of operations. An essential and key step in the preparation of an ignition target is the formation of a ~60 μm thick hydrogen "ice" layer on the inner surface of the target capsule. The Cryogenic Target Positioning System (Cryo-Tarpos) provides gas handling, cyro-cooling, x-ray imaging systems, and related instrumentation to control the volumes and temperatures of the multiphase (solid, liquid, and gas) hydrogen as the gas is condensed to liquid, admitted to the capsule, and frozen as a single spherical crystal of hydrogen in the capsule. The hydrogen fuel gas is prepared in discrete 1.7 cc aliquots in the LLNL Tritium Facility for each ignition shot. Post-shot hydrogen gas is recovered in the NIF Tritium Processing System (TPS). Gas handling systems, instrumentation and analytic equipment, material accounting information systems, and the shot planning systems must work together to ensure that operational and safety requirements are met. PMID:23629062

  11. Conceptual design of laser fusion reactor KOYO-F based on fast ignition scheme

    International Nuclear Information System (INIS)

    Recent progress on fast ignition (FI) enables us to design an IFE power plant with a 1MJ-class, compact laser whose output energy is 1/4 of previous central ignition scheme. Basing on the FI scheme, we conceptually designed a laser fusion power plant driven with cooled-Yb:YAG, ceramic lasers. In this design activity, we newly evaluated the gain curve for FI basing on latest simulation code. Cooled Yb-YAG ceramic was newly chosen as the laser material. We found that the heating laser for ignition could be constructed with the cooled Yb:YAG ceramics as well as the compression laser with acceptable electricity-laser conversion efficiencies including the electric power for the cooling system. New reactor scheme for a liquid wall reactor that has no stagnation point of ablated gas and a rotary shutter system to protect the final optics are proposed. (author)

  12. Machine learning models for the differential diagnosis of vascular parkinsonism and Parkinson's disease using [123I]FP-CIT SPECT

    International Nuclear Information System (INIS)

    The study's objective was to develop diagnostic predictive models using data from two commonly used [123I]FP-CIT SPECT assessment methods: region-of-interest (ROI) analysis and whole-brain voxel-based analysis. We included retrospectively 80 patients with vascular parkinsonism (VP) and 164 patients with Parkinson's disease (PD) who underwent [123I]FP-CIT SPECT. Nuclear-medicine specialists evaluated the scans and calculated bilateral caudate and putamen [123I]FP-CIT uptake and asymmetry indices using BRASS software. Statistical parametric mapping (SPM) was used to compare the radioligand uptake between the two diseases at the voxel level. Quantitative data from these two methods, together with potential confounding factors for dopamine transporter availability (sex, age, disease duration and severity), were used to build predictive models following a tenfold cross-validation scheme. The performance of logistic regression (LR), linear discriminant analysis and support vector machine (SVM) algorithms for ROI data, and their penalized versions for SPM data (penalized LR, penalized discriminant analysis and SVM), were assessed. Significant differences were found in the ROI analysis after covariate correction between VP and PD patients in [123I]FP-CIT uptake in the more affected side of the putamen and the ipsilateral caudate. Age, disease duration and severity were also found to be informative in feeding the statistical model. SPM localized significant reductions in [123I]FP-CIT uptake in PD with respect to VP in two specular clusters comprising areas corresponding to the left and right striatum. The diagnostic predictive accuracy of the LR model using ROI data was 90.3 % and of the SVM model using SPM data was 90.4 %. The predictive models built with ROI data and SPM data from [123I]FP-CIT SPECT provide great discrimination accuracy between VP and PD. External validation of these methods is necessary to confirm their applicability across centres. (orig.)

  13. CERN apprenticeships honoured at the Cité des Métiers

    CERN Multimedia

    2006-01-01

    Florian Métral, an electronics apprentice at CERN, accepting his prize at the award ceremony.CERN's exhibition stand at the Cité des Métiers et des Formations. CERN has just taken part in the Cité des Métiers et des Formations for the first time. This job and training fair, designed to assist both young people and adults in their choice of profession, training or career change, was held at Palexpo, Geneva's main exhibition centre, from 13 to 19 November. CERN had its own stand, where the Laboratory's activities and its many different trades and training opportunities were on display. Throughout the week and the weekend, a series of guides and members of the HR Department took it in turns to present CERN and the wide range of training it offers students and apprentices. Apprentices came into the spotlight on 13 November, when the Union Industrielle Genevoise awarded prizes to the eight most meritorious apprentices in the field of mecatronics (mechanical and electronics engineering) in the Canton of Gene...

  14. Dopamine transporter imaging in the aged rat: a [123I]FP-CIT SPECT study

    International Nuclear Information System (INIS)

    Introduction: Rodent models are extensively used to assess the biochemical and physiological changes associated with aging. They play a major role in the development of therapies for age-related pathologies such as Parkinson's disease. To validate the usefulness of these animal models in aging or age-related disease research, the consistency of cerebral aging processes across species must be evaluated. The dopaminergic system seems particularly susceptible to the aging process. One of the results of this susceptibility is a decline in striatal dopamine transporter (DAT) availability. Methods: We sought to ascertain whether similar age changes could be detected in-vivo in rats, using molecular imaging techniques such as single photon emission computed tomography (SPECT) with [123I]FP-CIT. Results: A significant decrease of 17.21% in the striatal specific uptake ratio was observed in the aged rats with respect to the young control group. Conclusions: Our findings suggest that age-related degeneration in the nigrostriatal track is similar in humans and rats, which supports the use of this animal in models to evaluate the effect of aging on the dopaminergic system. Advances in Knowledge and Implications for patient Care: Our findings indicate that age-related degeneration in the nigrostriatal track is similar in humans and rats and that these changes can be monitored in vivo using small animal SPECT with [123I]FP-CIT, which could facilitate the translational research in rat models of age related disorders of dopaminergic system

  15. IBZM- and CIT-SPECT of the dopaminergic system in Parkinsonism

    International Nuclear Information System (INIS)

    Parkinsonism is most of the time caused by idiopathic Parkinson's disease (IPD). Considering the differences in therapeutic response and prognosis. in viva discrimination between IPD and 'Parkinsonism-plus' syndromes is important. Recently, ligands have become available for imaging the pre- and postsynaptic dopaminergic system by Single Photon Emission Computed Tomography (SPECT). Visualization of postsynaptic D2 dopamine receptors using 123I-iodobenzamide (123I-IBZM) may contribute to the differential diagnosis between IPD and 'Parkinsonism-plus' syndromes as IPD is a pure presynaptic disease. Imaging of the presynaptic dopamine transporters using [123I]β-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane) may be used as a diagnostic technique. Early disease detection in subjects suspected to be at risk for developing IPD has become possible using [123I]β-CIT or other ligands for the dopamine transporter. Furthermore, with SPECT one is probably able to monitor in an objective way the efficacy of new pharmacological therapies. (author)

  16. 123I-Beta-CIT SPECT for the diagnosis of diffuse Lewy Body Disease

    International Nuclear Information System (INIS)

    Full text: Diffuse Lewy Body Disease (DLB) has been recently recognised as causing up to 20% of dementia. Clinical diagnosis is difficult with most cases diagnosed post mortem. Parkinsonian features, visual hallucinations, and fluctuating cognitive deficits are the cardinal clinical diagnostic features. As it is likely that there is a loss of dopamenergic fibres in this condition, we have commenced a study to compare dopamine transporter binding in patients with Diffuse Lewy Body Disease and Alzheimer's disease. To date, two patients with DLB and three patients with mild AD have received 150 MBq of 123I-Beta-CIT and been scanned 18-24 hours later on a triple headed SPECT camera. Circular regions-of-interest were placed over peak activity in the caudate nuclei, the immediately adjacent putamen, and in the occipital cortex. V3'' (basal ganglia minus occipital activity divided by occipital activity) and ratio of putamen to caudate nucleus were calculated. Both patients with DLB had reduced relative activity in the putamen to caudate nucleus (mean = 0.50) compared to AD subjects (mean = 0.68). V3'' was reduced but with some overlap with AD. The findings are consistent with the hypothesis of dopaminergic neurone loss in DLB and 123I-Beta-CIT SPECT shows promise as a test to distinguish DLB from AD. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  17. Nitrogen assimilation in Citrus based on CitEST data mining

    Directory of Open Access Journals (Sweden)

    Ester Wickert

    2007-01-01

    Full Text Available Assimilation of nitrate and ammonium are vital procedures for plant development and growth. From these primary paths of inorganic nitrogen assimilation, this metabolism integrates diverse paths for biosynthesis of macromolecules, such as amino acids and nucleotides, and the central intermediate metabolism, like carbon metabolism and photorespiration. This paper reports research performed in the CitEST (Citrus Expressed Sequence Tag database for the main genes involved in nitrogen metabolism and those previously described in other organisms. The results show that a complete cluster of genes involved in the assimilation of nitrogen and the metabolisms of glutamine, glutamate, aspartate and asparagine can be found in the CitEST data. The main enzymes found were nitrate reductase (NR, nitrite reductase (NiR, glutamine synthetase (GS, glutamate synthetase (GOGAT, glutamate dehydrogenase (GDH, aspartate aminotransferase (AspAT and asparagine synthetase (AS. The different enzymes involved in this metabolism have been shown to be highly conserved among the Citrus and Poncirus species. This work serves as a guide for future functional analysis of these enzymes in citrus.

  18. Les récits de la menthe en domaine basque : un discours mythique sur le mariage ?

    OpenAIRE

    Videgain, Charles

    1995-01-01

    This work tries to give a significance to the various accounts of oral source in which mint, in general, is used as criterion to distinguish a quality ground from a poor ground. These accounts were collected from Basque speakers into Basse-Navarre and Soule. Ce travail essaie de donner une signification aux divers récits de source orale dans lesquels la menthe, en général, sert de critère pour distinguer une terre de qualité d'une terre médiocre. Ces récits ont été recueillis auprès de loc...

  19. Evidence of statistical epistasis between DISC1, CIT and NDEL1 impacting risk for schizophrenia: biological validation with functional neuroimaging.

    Science.gov (United States)

    Nicodemus, Kristin K; Callicott, Joseph H; Higier, Rachel G; Luna, Augustin; Nixon, Devon C; Lipska, Barbara K; Vakkalanka, Radhakrishna; Giegling, Ina; Rujescu, Dan; St Clair, David; Muglia, Pierandrea; Shugart, Yin Yao; Weinberger, Daniel R

    2010-04-01

    The etiology of schizophrenia likely involves genetic interactions. DISC1, a promising candidate susceptibility gene, encodes a protein which interacts with many other proteins, including CIT, NDEL1, NDE1, FEZ1 and PAFAH1B1, some of which also have been associated with psychosis. We tested for epistasis between these genes in a schizophrenia case-control study using machine learning algorithms (MLAs: random forest, generalized boosted regression andMonteCarlo logic regression). Convergence of MLAs revealed a subset of seven SNPs that were subjected to 2-SNP interaction modeling using likelihood ratio tests for nested unconditional logistic regression models. Of the 7C2 = 21 interactions, four were significant at the α = 0.05 level: DISC1 rs1411771-CIT rs10744743 OR = 3.07 (1.37, 6.98) p = 0.007; CIT rs3847960-CIT rs203332 OR = 2.90 (1.45, 5.79) p = 0.003; CIT rs3847960-CIT rs440299 OR = 2.16 (1.04, 4.46) p = 0.038; one survived Bonferroni correction (NDEL1 rs4791707-CIT rs10744743 OR = 4.44 (2.22, 8.88) p = 0.00013). Three of four interactions were validated via functional magnetic resonance imaging (fMRI) in an independent sample of healthy controls; risk associated alleles at both SNPs predicted prefrontal cortical inefficiency during the N-back task, a schizophrenia-linked intermediate biological phenotype: rs3847960-rs440299; rs1411771-rs10744743, rs4791707-rs10744743 (SPM5 p < 0.05, corrected), although we were unable to statistically replicate the interactions in other clinical samples. Interestingly, the CIT SNPs are proximal to exons that encode theDISC1 interaction domain. In addition, the 3' UTR DISC1 rs1411771 is predicted to be an exonic splicing enhancer and the NDEL1 SNP is ~3,000 bp from the exon encoding the region of NDEL1 that interacts with the DISC1 protein, giving a plausible biological basis for epistasis signals validated by fMRI. PMID:20084519

  20. CcpA-independent regulation of expression of the Mg2+-citrate transporter gene citM by arginine metabolism in Bacillus subtilis

    NARCIS (Netherlands)

    Warner, JB; Magni, C; Lolkema, JS; Warner, Jessica B.

    2003-01-01

    Transcriptional regulation of the Mg2+ -citrate transporter, CitM, the main citrate uptake system of Bacillus subtilis, was studied during growth in rich medium. Citrate in the growth medium was required for induction under all growth conditions. In Luria-Bertani medium containing citrate, citM expr

  1. Piezoelectric Ignition of Nanocomposite Energetic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Eric Collins; Michelle Pantoya; Andreas A. Neuber; Michael Daniels; Daniel Prentice

    2014-01-01

    Piezoelectric initiators are a unique form of ignition for energetic material because the current and voltage are tied together by impact loading on the crystal. This study examines the ignition response of an energetic composite composed of aluminum and molybdenum trioxide nanopowders to the arc generated from a lead zirconate and lead titanate piezocrystal. The mechanical stimuli used to activate the piezocrystal varied to assess ignition voltage, power, and delay time of aluminum–molybdenum trioxide for a range of bulk powder densities. Results show a high dielectric strength leads to faster ignition times because of the higher voltage delivered to the energetic. Ignition delay is under 0.4 ms, which is faster than observed with thermal or shock ignition. Electric ignition of composite energetic materials is a strong function of interparticle connectivity, and thus the role of bulk density on electrostatic discharge ignition sensitivity is a focus of this study. Results show that the ignition delay times are dependent on the powder bulk density with an optimum bulk density of 50%. Packing fractions and electrical conductivity were analyzed and aid in explaining the resulting ignition behavior as a function of bulk density.

  2. cit et vérité chez Tzvetan Todorov

    Directory of Open Access Journals (Sweden)

    Miriana Alexandrova Yanakieva

    2014-05-01

    Full Text Available L’article se propose d’étudier certains aspects de la relation entre récit et vérité dans l’œuvre critique de Tzvetan Todorov. Pour lui la recherche de la vérité a toujours été étroitement liée à son intérêt inlassable pour le récit, pour l’acte de raconter et ses effets. D’abord, le récit littéraire était l’objet préféré de son travail de théoricien du structuralisme et de la sémiotique. Ce travail touchait à la question de la vérité sous deux aspects: la vérité d’une science de la littérature qui voulait offrir une approche objective à l’étude littéraire, et la vérité ou, plus précisément, la vraisemblance dans la fiction littéraire elle-même. Dans les écrits de Todorov l’anthropologue et l’humaniste, la liaison entre récit et vérité reste toujours aussi importante. Pour lui, la meilleure manière de réfléchir sur un sujet important, c’est de « raconter une histoire » (La conquête de l’Amérique. Il montre que chaque récit peut avoir trait à deux types de vérité – la vérité d’adéquation et la vérité de dévoilement. Le texte qui suit s’intéresse aussi au rôle que les concepts de rhétorique, interprétation, mémoire et intersubjectivité joue dans la méditation de Todorov sur la question de la vérité, plus spécialement, de la vérité de dévoilement.The article deals with some aspects of the relationship between narrative and truth in the critical work of Tzvetan Todorov. For him the search for the truth has always been closely related to his untiring interest for the narrative, and for the act of narrating and its effects. At first, the literary narrative was the fa- vorite object of his work as a theoretician of Structuralism and Semiotics. This work was coming to the question of truth in two ways: the truth of the literary science, which would give an objective approach to the literary studies, and the truth, or, more exactly, the vraisemblance

  3. Compact balanced tries

    OpenAIRE

    Nicodeme, Pierre

    1991-01-01

    We show how it is possible to split Compact Tries described as bit-lists in a segmented and flexible structure of B-tree type, keeping the compactness advantages of the Compact Tries and recovering all the important properties of B-trees.

  4. Particle Simulation of Fusion Ignition

    International Nuclear Information System (INIS)

    Full text: A new molecular dynamics (MD) particle simulation code has been developed to study inertial fusion ignition physics including effects of a non-Maxwellian ion velocity distribution. 10,000 DT ions at density 100 g/cc and temperatures of several keV are followed for 10 to 20 psec. The simulation includes ion-ion collisions, electron-ion coupling and emission and absorption of radiation. Fusion reactions produce energetic alphas which deposit energy to electrons and ions and the plasma self-heats to 20 — 30 keV. This simulation using realistic particles and interactions poses the scientific challenge of including quantum processes (fusion, radiation) in a classical particle simulation and the computational challenge of following the calculation for long enough to see significant plasma self-heating. The paper gives a detailed discussion of special physical and numerical techniques which make it possible to do such a simulation. The molecular dynamics is carefully compared to hydrodynamic simulations of small plasma volumes to test both codes. The most important new physics in MD simulations is the possibility to include a non-Maxwell ion velocity distribution f (υ); fusion reaction rates are very sensitive to the high-energy tail of f (υ), which depends delicately on plasma transport and equilibration processes. Although equilibrium ion-pair correlation is not strong in multi-keV plasmas we find substantial dynamical correlations caused by alpha-particle energy transfers. It is found that calculations starting from a variety of initial conditions evolve to follow a unique self-heating trajectory, an ignition attractor. Calculations starting with 3 keV DT heat to ignition within a few psec after a pulse of energetic ions are injected; this shows that fast ions are quite effective for fast ignition of precompressed DT. A series of such calculations are performed to determine the threshold ion deposition heating required to ignite DT fuel within the short

  5. A sustained-arc ignition system for internal combustion engines

    Science.gov (United States)

    Birchenough, A. G.

    1977-01-01

    A sustained-arc ignition system was developed for internal combustion engines. It produces a very-long-duration ignition pulse with an energy in the order of 100 millijoules. The ignition pulse waveform can be controlled to predetermined actual ignition requirements. The design of the sustained-arc ignition system is presented in the report.

  6. [O-methyl-11C]β-CIT-FP, a potential radioligand for quantitation of the dopamine transporter: Preparation, autoradiography, metabolite studies, and positron emission tomography examinations

    International Nuclear Information System (INIS)

    β-CIT-FP [N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl)nortropane] is a cocaine analogue with a high affinity for the dopamine transporter. [O-methyl-11C]β-CIT-FP ([11C]β-CIT-FP) was prepared byO -alkylation of the free acid with [11C]methyl iodide. The total radiochemical yield of [11C]β-CIT-FP was 50 to 60% with an overall synthesis time of 30 min. The radiochemical purity was >99%, and the specific radioactivity at time of injection was about 37 GBq/μmol (1000 Ci/mmol). Autoradiographic examination of [11C]β-CIT-FP binding in human brain postmortem demonstrated specific binding in the caudate nucleus and putamen. Positron emission tomography (PET) examination of [11C]β-CIT-FP in a Cynomolgus monkey demonstrated accumulation in the striatum with a striatum-to-cerebellum ratio of about 8 after 60 min. Equilibrium in the striatum was attained within 70 to 90 min. The radioactivity ratios of thalamus/cerebellum and neocortex/cerebellum were about 2 and 1.5, respectively. In a displacement experiment, radioactivity in the striatum but not in the cerebellum was reduced after injection of β-CIT, indicating that striatal radioactivity following injection of [11C]β-CIT-FP is associated with dopamine transporter sites and that the binding is reversible. The fraction of the total radioactivity in plasma representing [11C]β-CIT-FP determined by high-performance liquid chromatography (HPLC) was 84% at 15 min and 50% at 95 min. [11C]β-CIT-FP should be a useful PET radioligand for the quantitation of dopamine transporters in the human brain in vivo

  7. Ignition of hydrogen/oxygen/nitrogen mixtures exposed to two configuration dependent ignition sources

    International Nuclear Information System (INIS)

    White Sands Test Facility performed a series of tests to determine the ignition characteristic of hydrogen/oxygen/nitrogen mixtures. The testing was performed to assess the ignition hazard on board the Space Transportation System (STS) from possible leakage of hydrogen, oxygen and nitrogen. The ignition sources consisted of an exhaust duct that exposed a heated surface through a 1/4 inch crack in the insulation and a heated surface that existed at the bottom of a 0.75-inch diameter, 2-inch long tube. These ignition sources were fabricated to simulate the exhaust duct and the hydrazine injector tube in the auxiliary power unit on board the STS. The data obtained using these ignition sources were compared with data obtained using common ignition sources such as electrical spark, hot surfaces, etc. The results indicated that the configuration aspects of the ignition source had significant affects on the ignition characteristics of hydrogen mixtures

  8. Studies into laser ignition of confined pyrotechnics

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.R.; Russell, D.A. [Centre for Applied Laser Spectroscopy, DASSR, Defence Academy, Cranfield University, Shrivenham, Swindon (United Kingdom)

    2008-10-15

    Ignition tests were carried out on three different pyrotechnics using laser energy from the multimode output from an Ar-Ion laser (av) at 500 nm and a near-IR diode laser pigtailed to a fibre optic cable and operating at 808 nm. The pyrotechnics investigated were: G20 black powder, SR44 and SR371C. The confined ignition tests were conducted in a specially designed ignition chamber. Pyrotechnics were ignited by a free space beam entering the chamber through an industrial sapphire window in the case of the Ar-ion laser. For the NIR diode laser, fibre was ducted through a block into direct contact with the pyrotechnic. The Ar-Ion laser was chosen as this was found to ignite all three pyrotechnics in the unconfined condition. It also allowed for a direct comparison of confined/unconfined results to be made. The threshold laser flux densities to initiate reproducible ignitions at this wavelength were found to be between {proportional_to}12.7 and {proportional_to}0.16 kW cm{sup -2}. Plotted on the ignition maps are the laser flux densities versus the start of ignition times for the three confined pyrotechnics. It was found from these maps that the times for confined ignition were substantially lower than those obtained for unconfined ignition under similar experimental conditions. For the NIR diode laser flux densities varied between {proportional_to}6.8 and {proportional_to}0.2 kW cm{sup -2}. The minimum ignition times for the NIR diode laser for SR371C ({proportional_to}11.2 ms) and G20 ({proportional_to}17.1 ms) were faster than those achieved by the use of the Ar-ion laser. However, the minimum ignition time was shorter ({proportional_to}11.7 ms) with the Ar-ion laser for SR44. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  9. Pyrotechnic Igniters for Liquid Propellant Gun .

    Directory of Open Access Journals (Sweden)

    D. K. Kharat

    1997-04-01

    Full Text Available The results of a preliminary investigation on the use of liquid propellant for gun application are presented. Both regenerative and bulk loaded liquid propellant guns were used in the study.Pyrotechnic igniters were tried out for igniting the liquid propellant. Existing pyrotechnic igniters were suitably modified to obtain pressure beyond 20 MPa in less than 3 ms in the combustion chamber.

  10. Analysis of the National Ignition Facility ignition hohlraum energetics experiments

    International Nuclear Information System (INIS)

    A series of 40 experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] to study energy balance and implosion symmetry in reduced- and full-scale ignition hohlraums was shot at energies up to 1.3 MJ. This paper reports the findings of the analysis of the ensemble of experimental data obtained that has produced an improved model for simulating ignition hohlraums. Last year the first observation in a NIF hohlraum of energy transfer between cones of beams as a function of wavelength shift between those cones was reported [P. Michel et al., Phys. Plasmas 17, 056305 (2010)]. Detailed analysis of hohlraum wall emission as measured through the laser entrance hole (LEH) has allowed the amount of energy transferred versus wavelength shift to be quantified. The change in outer beam brightness is found to be quantitatively consistent with LASNEX [G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Controlled Fusion 2, 51 (1975)] simulations using the predicted energy transfer when possible saturation of the plasma wave mediating the transfer is included. The effect of the predicted energy transfer on implosion symmetry is also found to be in good agreement with gated x-ray framing camera images. Hohlraum energy balance, as measured by x-ray power escaping the LEH, is quantitatively consistent with revised estimates of backscatter and incident laser energy combined with a more rigorous non-local-thermodynamic-equilibrium atomic physics model with greater emissivity than the simpler average-atom model used in the original design of NIF targets.

  11. Lateral Ignition and Flame Spread Apparatus

    Data.gov (United States)

    Federal Laboratory Consortium — Description: This apparatus, developed at EL, determines material properties related to piloted ignition of a vertically oriented sample under constant and uniform...

  12. Modelling piloted ignition of wood and plastics

    International Nuclear Information System (INIS)

    Highlights: ► We model piloted ignition times of wood and plastics. ► The model is applied on a packed bed. ► When the air flow is above a critical level, no ignition can take place. - Abstract: To gain insight in the startup of an incinerator, this article deals with piloted ignition. A newly developed model is described to predict the piloted ignition times of wood, PMMA and PVC. The model is based on the lower flammability limit and the adiabatic flame temperature at this limit. The incoming radiative heat flux, sample thickness and moisture content are some of the used variables. Not only the ignition time can be calculated with the model, but also the mass flux and surface temperature at ignition. The ignition times for softwoods and PMMA are mainly under-predicted. For hardwoods and PVC the predicted ignition times agree well with experimental results. Due to a significant scatter in the experimental data the mass flux and surface temperature calculated with the model are hard to validate. The model is applied on the startup of a municipal waste incineration plant. For this process a maximum allowable primary air flow is derived. When the primary air flow is above this maximum air flow, no ignition can be obtained.

  13. Spontaneously Igniting Hybrid Fuel-Oxidiser Systems

    OpenAIRE

    Jain, S. R.

    1995-01-01

    After briefly outlining the recent developments in hybrid rockets, the work carried out by the author on self-igniting (hypergolic) solid fuel-liquid oxidiser systems has been reviewed. A major aspect relates to the solid derivatives of hydrazines, which have been conceived as fuels for hybrid rockets. Many of these N-N bonded compounds ignite readily, with very short ignition delays, on coming into contact with liquid oxidisers, like HNO/sub 3/ and N/sub 2/ O/sub 4/. The ignition char...

  14. Dopaminergic dysfunction and psychiatric symptoms in movement disorders: a 123I-FP-CIT SPECT study

    International Nuclear Information System (INIS)

    Psychiatric symptoms frequently occur in patients with movement disorders. They are not a mere reaction to chronic disability, but most likely due to a combination of psychosocial factors and biochemical dysfunction underlying the movement disorder. We assessed dopamine transporter (DAT) availability by means of 123I-FP-CIT SPECT, and motor and psychiatric features in patients with Parkinson's disease, primary dystonia and essential tremor, exploring the association between SPECT findings and symptom severity. Enrolled in the study were 21 patients with Parkinson's disease, 14 patients with primary dystonia and 15 patients with essential tremor. The severity of depression symptoms was assessed using the Hamilton depression rating scale, anxiety levels using the Hamilton anxiety rating scale and hedonic tone impairment using the Snaith-Hamilton pleasure scale. Specific 123I-FP-CIT binding in the caudate and putamen was calculated based on ROI analysis. The control group included 17 healthy subjects. As expected, DAT availability was significantly decreased in patients with Parkinson's disease, whereas in essential tremor and dystonia patients it did not differ from that observed in the control group. In Parkinson's disease patients, an inverse correlation between severity of depression symptoms and DAT availability in the left caudate was found (r = -0.63, p = 0.002). In essential tremor patients, levels of anxiety symptoms were inversely correlated with DAT availability in the left caudate (r = -0.69, p = 0.004). In dystonia patients, the severities of both anxiety and depression symptoms were inversely associated with DAT availability in the left putamen (r = -0.71, p = 0.004, and r = -0.75, p = 0.002, respectively). There were no correlations between psychometric scores and 123I-FP-CIT uptake ratios in healthy subjects. We found association between presynaptic dopaminergic function and affective symptoms in different movement disorders. Interestingly, the inverse

  15. Trajets quotidiens et récits délinquants

    Directory of Open Access Journals (Sweden)

    Michael Sheringham

    2007-08-01

    Full Text Available Dossier/Issue: 1 - Raconter le quotidien aujourd'hui - Si l’expérience de la quotidienneté, qui préoccupe un philosophe comme Henri Lefebvre ou un écrivain comme Georges Perec, semble résister à l’emprise du roman, Michel de Certeau a pu mettre une réflexion sur le récit au cœur de son essai fondamental, L’invention du quotidien. En effet, les notions de « récits délinquants » ou d’« énonciations piétonnières », chez Certeau, fournissent des outils précieux pour l’élucidation du rôle du récit dans des textes qui interrogent le monde quotidien à partir de pérégrinations et de méditations urbaines, dont certains exemples majeurs sont traités ici : Un ethnologue dans le métro (Marc Augé, Journal du dehors (Annie Ernaux, Les passagers du Roissy-Express (François Maspero, La liberté des rues (Jacques Réda.If the experience of everydayness, which preoccupied a philosopher like Henri Lefebvre and a writer like Georges Perec, seem to resist the sway of the novel, Michel de Certeau nonetheless placed a consideration of narrative at the heart of his seminal essay Practices of Everyday Life. And indeed such notions as "delinquent narratives" and "pedestrian speech acts", elaborated by Certeau, provide precious tools for identifying the role of narrative in texts which interrogate the everyday world on the basis of urban peregrinations and meditations, of which some major examples are examined here : An Ethnologist in the Metro (Marc Augé, Exteriors (Annie Ernaux, Roissy-Express : A Journey Through the Paris Suburbs (François Maspero, The Freedom of the Streets (Jacques Réda.

  16. Serotonin transporters in Parkinson's disease studied with [I-123)β-CIT SPECT

    International Nuclear Information System (INIS)

    In Parkinson's disease (PD), both neuropathological and biochemical studies suggest that serotonin (5-HT) neurons are affected by the disease process. The purpose of this study was to assess the integrity of 5-HT transporters in PD using [I-123]β-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane], which binds to both 5-HT and dopamine transporters, and SPECT. Forty-five patients with PD at relatively early stages (Hoehn-Yahr stages I-3) and seven agematched healthy controls were injected with 185-370 MBq(I-123]β-CIT. A total of 15 SPECT scans were acquired over a 24 hr period in each subject using a three-headed system. Time activity curves were obtained in the hypothalamic/midbrain region, where the binding of [I-123] β-CIT is associated primarily with 5-HT transporters, and cerebellum, which was assumed to include only nondisplaceable activity. The parameter k3/k4 (forward/dissociation rate), which is a measure of 5-HT transporter density, was estimated by four noninvasive methods: peak equilibrium ratio (PER) [the ratio of specific binding (hypothalamic/midbrain region-cerebellar activity) to nondisplaceable (cerebella) activity when specific binding reaches a peak], area ratio (the ratio of the areas under the specific binding and nondisplaceable activity curves), k3/k4 obtained using a kinetic two-compartment model [R(2C)], and k3/k4 from a modified graphic method [R(DV)] (Ichise et al., 1996). In the healthy controls, the activity in the hypothalamic/midbrain area generally peaked by 3 hr after tracer injection, then decreased slowly; similar patterns were observed in the PD patients. The k3/k4 values estimated by four different methods in the PD patients did not differ significanlty from those in the healthy controls. In the PD patients, the k3/k4 estimates were not significantly correlated with either Hoehn-Yahr scale or UPDRS (Unified Parkinson's Disease Rating Scale) scores, including total, motor, activities of daily living and affection scores of UPDRS

  17. Calibration of gamma camera systems for a multicentre European ¹²³I-FP-CIT SPECT normal database

    DEFF Research Database (Denmark)

    Tossici-Bolt, Livia; Dickson, John C; Sera, Terez;

    2011-01-01

    A joint initiative of the European Association of Nuclear Medicine (EANM) Neuroimaging Committee and EANM Research Ltd. aimed to generate a European database of [(123)I]FP-CIT single photon emission computed tomography (SPECT) scans of healthy controls. This study describes the characterization and...

  18. Mutations in CIT, encoding citron rho-interacting serine/threonine kinase, cause severe primary microcephaly in humans.

    Science.gov (United States)

    Shaheen, Ranad; Hashem, Amal; Abdel-Salam, Ghada M H; Al-Fadhli, Fatima; Ewida, Nour; Alkuraya, Fowzan S

    2016-10-01

    Primary microcephaly is a clinical phenotype in which the head circumference is significantly reduced at birth due to abnormal brain development, primarily at the cortical level. Despite the marked genetic heterogeneity, most primary microcephaly-linked genes converge on mitosis regulation. Two consanguineous families segregating the phenotype of severe primary microcephaly, spasticity and failure to thrive had overlapping autozygomes in which exome sequencing identified homozygous splicing variants in CIT that segregate with the phenotype within each family. CIT encodes citron, an effector of the Rho signaling that is required for cytokinesis specifically in proliferating neuroprogenitors, as well as for postnatal brain development. In agreement with the critical role assigned to the kinase domain in effecting these biological roles, we show that both splicing variants predict variable disruption of this domain. The striking phenotypic overlap between CIT-mutated individuals and the knockout mice and rats that are specifically deficient in the kinase domain supports the proposed causal link between CIT mutation and primary microcephaly in humans. PMID:27503289

  19. Evaluation of Multiple System Atrophy and Early Parkinson's Disease Using {sup 123}I-FP-CIT SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Oh, So Won; Kim, Yu Kyeong; Lee, Byung Chul; Kim, Bom Sahn; Kim, Ji Sun; Kim, Jong Min; Kim, Sang Eun [Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2009-02-15

    We investigated quantification of dopaminergic transporter (DAT) and serotonergic transporter (SERT) on {sup 123}I-FP-CIT SPECT for differentiating between multiple systemic atrophy (MSA) and idiopathic Parkinson's disease (IPD). N.fluoropropyl-2{beta}-carbomethoxy-3{beta}-4-[{sup 123}I]-iodophenylnortropane SPECT ({sup 123}I-FP-CIT SPECT) was performed in 8 patients with MSA (mean age: 64.0{+-}4.5yrs, m:f=6:2), 13 with early IPD (mean age: 65.5{+-}5.3yrs, m:f=9:4), and 12 healthy controls (mean age: 63.3{+-}5.7yrs, m:f=8:4). Standard regions of interests (ROIs) of striatum to evaluate DAT, and hypothalamus and midbrain for SERT were drawn on standard template images and applied to each image taken 4 hours after radiotracer injection. Striatal specific binding for DAT and hypothalamic and midbrain specific binding for SERT were calculated using region/reference ratio based on the transient equilibrium method. Group differences were tested using ANOVA with the postHoc analysis. DAT in the whole striatum and striatal subregions were significantly decreased in both patient groups with MSA and early IPD, compared with healthy control (p<0.05 in all). In early IPD, a significant increase in the uptake ratio in anterior and posterior putamen and a trend of increase in caudate to putamen ratio was observed. In MSA, the decrease of DAT was accompanied with no difference in the striatal uptake pattern compared with healthy controls. Regarding the brain regions where {sup 123}I-FP-CIT binding was predominant by SERT, MSA patients showed a decrease in the binding of {sup 123}I-FP-CIT in the pons compared with controls as well as early IPD patients (MSA: 0.22{+-}0.1 healthy controls: 0.33{+-}0.19, IPD: 0.29{+-}0.19), however, it did not reach the statistical significance. In this study, the differential patterns in the reduction of DAT in the striatum and the reduction of pontine {sup 123}I- FP-CIT binding predominant by SERT could be observed in MSA patients on {sup 123

  20. J.-M.-G. Le Clézio et le récit poétique

    Directory of Open Access Journals (Sweden)

    Pascal Rannou

    2009-11-01

    Full Text Available Dans Le Récit poétique (1978, J.-Y. Tadié analyse les caractéristiques d’un genre un peu marginal, qui ne tient ni du roman, ni de la nouvelle, et se signale par une conception originale de l’espace, du temps et du personnage. Si Tadié évoque les œuvres de Limbour, Gracq ou Mandiargues, il ne mentionne pas celle de Le Clézio. Or, l’écriture de ce dernier correspond souvent aux critères formulés dans son essai. Les personnages de Le Clézio sont souvent des « êtres de fuite », prétextes à rêverie géographique, des anti-héros, peu actifs, contemplatifs. Ce sont souvent des marginaux en rupture de ban avec la société. Le lieu du récit poétique est pour Tadié un lieu de rêve, éloigné de la fureur urbaine, et c’est souvent le cas chez Le Clézio. Ce dernier a également tendance à diluer le temps pour le faire tendre au mythe, en négligeant les références précises. Le temps du récit poétique est souvent celui de l’enfance, ce que corrobore aussi Le Clézio, notamment dans Mondo et La Ronde, qui forment notre corpus. L’écriture de ce type de récit est proche du poème en prose. Elle cultive les parallélismes et le travail sur le signifiant. Mais les récits poétiques de Le Clézio s’éloignent aussi des critères définis par J.-Y. Tadié. Les personnages n’y sont pas que des prétextes à rêverie, mais les victimes de rouages sociaux qui les écrasent : voleurs, orphelins, mères célibataires, travailleurs immigrés. Le récit poétique leclézien s’éloigne, par sa dimension politique et sociale, du récit poétique défini par Tadié, qui se caractérise par une certaine gratuité.

  1. cits de vie d’adolescents. Humeur dépressive et figures parentales

    Directory of Open Access Journals (Sweden)

    Poudat Céline

    2014-07-01

    Full Text Available La présente étude se propose d’explorer d’explorer les liens entre l’humeur dépressive et le langage sur la base d’un corpus de récits de vie oraux spontanés produits par 206 adolescents âgés de 12 à 18 ans. On se concentrera plus spécifiquement sur les représentations des figures d’attachement parentales dans les discours, premiers paramètres à jouer un rôle déterminant pour spécifier les différences d’humeur de l’adolescent, en mobilisant des méthodes issues de l’analyse de données textuelles et de la linguistique de corpus.

  2. L’île, la cité et la rue

    Directory of Open Access Journals (Sweden)

    Jean Marie Théodat

    2008-06-01

    Full Text Available Parallèlement à la rubrique Sur le Vif qui rend compte en continu de l’actualité thématique, régionale et internationale, la revue Echogéo vous invite dans son nouveau cahier à explorer des lieux emblématiques. Leur appropriation par des populations confrontées à des situations souvent liées à l’exil, l’exclusion et la stigmatisation, crée des territoires à l’identité forte, singulière. C’est l’occasion d’explorer des dimensions fondamentales de la condition géographique : l’île, la cité et l...

  3. La laïcité entre universalisme et hiérarchie

    OpenAIRE

    Kilani, Mondher

    2010-01-01

    Je remercie François Sigaut d’avoir pris la peine de débattre d’un certain nombre de questions que je soulève dans mon texte paru dans le numéro 100‑101 du Journal des anthropologues. Si ses critiques effectuent quelquefois des déplacements qui dépassent le propos initial et le placent sur des terrains qu’il n’a pas choisi de traiter, du moins dans ce cadre précis, elles me donnent l’occasion de clarifier un certain nombre de points. Mon développement sur la laïcité était limité à la France e...

  4. L'UOIF:en face de la loi sur la la(i)cité

    Institute of Scientific and Technical Information of China (English)

    田俊雷; 申永杰

    2004-01-01

    La socié té francaise se caracté rise par le principe de la(i)cité. 《 L' affaire du foulard 》 existe en France depuisquelques anné es. Pour 1' instant, la question du voile se focalise sur les lycé es et sur quelques les colle ges. Le voile a causé un dé sé quilibre a 1'é cole. La France est cette socié té multiculturelle. Dans ce dossier, on pré sente la motivation et 1' objet dudossier en introduction. Ensuite dans deux parties distinctes, on dé crit le panorama des articles et on les analyse. Dans une autrepartie, on de veloppe son argumentation sur le sujet, et pour finir, la conclusion sur 1' objet du dossier.

  5. SPECT imaging using [123I]β-CIT and [123I]IBF in extrapyramidal diseases

    International Nuclear Information System (INIS)

    Imaging of dopaminergic function is useful in the investigation of patients with Parkinson disease (iPD) and other extrapyramidal diseases. Using agents that bind to dopamine transporters ([123I]β-CIT) and receptors ([123I]IBF SPECT), we investigated SPECT in 9 healthy volunteers and 24 patients for dopamine transporters as well as 15 patients for dopamine receptors. In β-CIT SPECT studies, we examined 17 iPD patients (63.3±9.9 y/o), 3 multiple system atrophy (MSA) patients (olivopontocerebellar atrophy (OPCA) type) (64.0±8.0 y/o), 2 vascular parkinsonism (VP) patients (71.0±0.0 y/o), 1 progressive supranuclear palsy (PSP) patient (69 y/o), 1 cortico-basal degeneration (CBD) patient (50 y/o) and nine healthy controls (39.1±9.3 y/o). For IBF SPECT studies 11 iPD patients (60.6±10.9 y/o), 3 MSA patients (2 OPCA type (50.5±3.5 y/o) and 1 striatonigral degeneration (SND) type (65 y/o)) and 1 PSP patient (60 y/o) underwent SPECT scans after the injection of [123I]IBF. The specific to nonspecific striatal ratio (St/Oc-1), ratio of putaminal uptake to caudatal uptake (Pu/Ca), and asymmetry indices (AI) were estimated. β-CIT studies showed ST/Oc-1 as follows; iPD: 2.66±1.09 (n=17), VP: 5.73 and 7.39, MSA: 1.84±0.46 (n=3), PSP: 2.34, CBD: 2.16. In all extrapyramidal diseases except VP, St/Oc-1 ratios were significantly lower than those in normal volunteers (6.46±1.08) (p<0.01). Also in early-phase iPD patients (Yahr I-II), St/Oc-1 (3.16±1.49: n=4) was significantly lower than those in normal volunteers (p<0.01). In IBF studies, St/Oc-1 ratios were significantly higher in early-phase (Yahr I-II) iPD patients (1.82±0.25: n=5) than those in late-phase (Yahr III-IV) iPD patients (1.38±0.32: n=6) (p<0.05). The Pu/Ca ratios in iPD patients (1.12±0.13) and MSA (OPCA type) patients (0.95±0.05) were higher than that in MSA (SND type) patient (0.78) and were lower than that in PSP patient (1.55). In conclusion, β-CIT-SPECT is useful for the diagnosis of early

  6. Nova marca de oleiro na Citânia de Sanfins

    Directory of Open Access Journals (Sweden)

    Eugenio JALHAY

    2009-10-01

    Full Text Available Na campanha de escavaçoes de 1949 da Citânia de Sanfins, quando se procedia á exploraçao da zona ondeapareceran as casa marcadas na nossa planta topográfica comos números 52 a 60, colheram-se num dia nove fragmentos duma pequena vasilha de barro, de pasta parda tendendo para cor de rosa, ordo notavelmene saliente, ornado na sua face superior com cinco sulcos concéntricos em toda a volta, bojo bastante pronunciado com igual ornamantaçao de sulcos em número de três, mais largos e mais profundos qu os do bordo, e sem asa.

  7. Automated Analysis of {sup 123}I-beta-CIT SPECT Images with Statistical Probabilistic Anatomical Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Eo, Jae Seon; Lee, Hoyoung; Lee, Jae Sung; Kim, Yu Kyung; Jeon, Bumseok; Lee, Dong Soo [Seoul National Univ., Seoul (Korea, Republic of)

    2014-03-15

    Population-based statistical probabilistic anatomical maps have been used to generate probabilistic volumes of interest for analyzing perfusion and metabolic brain imaging. We investigated the feasibility of automated analysis for dopamine transporter images using this technique and evaluated striatal binding potentials in Parkinson's disease and Wilson's disease. We analyzed 2β-Carbomethoxy-3β-(4-{sup 123}I-iodophenyl)tropane ({sup 123}I-beta-CIT) SPECT images acquired from 26 people with Parkinson's disease (M:F=11:15,mean age=49±12 years), 9 people with Wilson's disease (M: F=6:3, mean age=26±11 years) and 17 normal controls (M:F=5:12, mean age=39±16 years). A SPECT template was created using striatal statistical probabilistic map images. All images were spatially normalized onto the template, and probability-weighted regional counts in striatal structures were estimated. The binding potential was calculated using the ratio of specific and nonspecific binding activities at equilibrium. Voxel-based comparisons between groups were also performed using statistical parametric mapping. Qualitative assessment showed that spatial normalizations of the SPECT images were successful for all images. The striatal binding potentials of participants with Parkinson's disease and Wilson's disease were significantly lower than those of normal controls. Statistical parametric mapping analysis found statistically significant differences only in striatal regions in both disease groups compared to controls. We successfully evaluated the regional {sup 123}I-beta-CIT distribution using the SPECT template and probabilistic map data automatically. This procedure allows an objective and quantitative comparison of the binding potential, which in this case showed a significantly decreased binding potential in the striata of patients with Parkinson's disease or Wilson's disease.

  8. Automated Analysis of 123I-beta-CIT SPECT Images with Statistical Probabilistic Anatomical Mapping

    International Nuclear Information System (INIS)

    Population-based statistical probabilistic anatomical maps have been used to generate probabilistic volumes of interest for analyzing perfusion and metabolic brain imaging. We investigated the feasibility of automated analysis for dopamine transporter images using this technique and evaluated striatal binding potentials in Parkinson's disease and Wilson's disease. We analyzed 2β-Carbomethoxy-3β-(4-123I-iodophenyl)tropane (123I-beta-CIT) SPECT images acquired from 26 people with Parkinson's disease (M:F=11:15,mean age=49±12 years), 9 people with Wilson's disease (M: F=6:3, mean age=26±11 years) and 17 normal controls (M:F=5:12, mean age=39±16 years). A SPECT template was created using striatal statistical probabilistic map images. All images were spatially normalized onto the template, and probability-weighted regional counts in striatal structures were estimated. The binding potential was calculated using the ratio of specific and nonspecific binding activities at equilibrium. Voxel-based comparisons between groups were also performed using statistical parametric mapping. Qualitative assessment showed that spatial normalizations of the SPECT images were successful for all images. The striatal binding potentials of participants with Parkinson's disease and Wilson's disease were significantly lower than those of normal controls. Statistical parametric mapping analysis found statistically significant differences only in striatal regions in both disease groups compared to controls. We successfully evaluated the regional 123I-beta-CIT distribution using the SPECT template and probabilistic map data automatically. This procedure allows an objective and quantitative comparison of the binding potential, which in this case showed a significantly decreased binding potential in the striata of patients with Parkinson's disease or Wilson's disease

  9. National Ignition Facility for Inertial Confinement Fusion

    International Nuclear Information System (INIS)

    The National Ignition Facility for inertial confinement fusion will contain a 1.8 MJ, 500 TW frequency-tripled neodymium glass laser system that will be used to explore fusion ignition and other problems in the physics of high temperature and density. We describe the facility briefly. The NIF is scheduled to be completed in 2003

  10. Advanced ignition and propulsion technology program

    Energy Technology Data Exchange (ETDEWEB)

    Oldenborg, R.; Early, J.; Lester, C.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Reliable engine re-ignition plays a crucial role in enabling commercial and military aircraft to fly safely at high altitudes. This project addressed research elements critical to the optimization of laser-based igniter. The effort initially involved a collaborative research and development agreement with B.F. Goodrich Aerospace and Laser Fare, Inc. The work involved integrated experiments with theoretical modeling to provide a basic understanding of the chemistry and physics controlling the laser-induced ignition of fuel aerosols produced by turbojet engine injectors. In addition, the authors defined advanced laser igniter configurations that minimize laser packaging size, weight, complexity and power consumption. These innovative ignition concepts were shown to reliably ignite jet fuel aerosols over a broad range of fuel/air mixture and a t fuel temperatures as low as -40 deg F. The demonstrated fuel ignition performance was highly superior to that obtained by the state-of-the-art, laser-spark ignition method utilizing comparable laser energy. The authors also developed a laser-based method that effectively removes optically opaque deposits of fuel hydrocarbon combustion residues from laser window surfaces. Seven patents have been either issued or are pending that resulted from the technology developments within this project.

  11. Modelling piloted ignition of wood and plastics

    NARCIS (Netherlands)

    Blijderveen, M. van; Bramer, E.A.; Brem, G.

    2012-01-01

    To gain insight in the startup of an incinerator, this article deals with piloted ignition. A newly developed model is described to predict the piloted ignition times of wood, PMMA and PVC. The model is based on the lower flammability limit and the adiabatic flame temperature at this limit. The inco

  12. Self-Compacting Concrete

    OpenAIRE

    Okamura, Hajime; OUCHI, Masahiro

    2003-01-01

    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  13. Isochoric Implosions for Fast Ignition

    International Nuclear Information System (INIS)

    Various gain models have shown the potentially great advantages of Fast Ignition (FI) Inertial Confinement Fusion (ICF) over its conventional hot spot ignition counterpart [e.g., S. Atzeni, Phys. Plasmas 6, 3316 (1999); M. Tabak et al., Fusion Sci. and Technology 49, 254 (2006)]. These gain models, however, all assume nearly uniform-density fuel assemblies. In contrast, conventional ICF implosions yield hollowed fuel assemblies with a high-density shell of fuel surrounding a low-density, high-pressure hot spot. Hence, to realize fully the advantages of FI, an alternative implosion design must be found which yields nearly isochoric fuel assemblies without substantial hot spots. Here, it is shown that a self-similar spherical implosion of the type originally studied by Guderley [Luftfahrtforschung 19, 302 (1942)] may be employed to yield precisely such quasi-isochoric imploded states. The difficulty remains, however, of accessing these self-similarly imploding configurations from initial conditions representing an actual ICF target, namely a uniform, solid-density shell at rest. Furthermore, these specialized implosions must be realized for practicable drive parameters and at the scales and energies of interest in ICF. A direct-drive implosion scheme is presented which meets all of these requirements and reaches a nearly isochoric assembled density of 300 g=cm3 and areal density of 2.4 g=cm2 using 485 kJ of laser energy

  14. Note: A monoenergetic proton backlighter for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Rygg, J. R.; LePape, S.; Bachmann, B.; Khan, S. F.; Sayre, D. B. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Zylstra, A. B.; Séguin, F. H.; Gatu-Johnson, M.; Lahmann, B. J.; Petrasso, R. D.; Sio, H. W. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Craxton, R. S.; Garcia, E. M.; Kong, Y. Z.; McKenty, P. W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Rinderknecht, H. G. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Rosenberg, M. J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2015-11-15

    A monoenergetic, isotropic proton source suitable for proton radiography applications has been demonstrated at the National Ignition Facility (NIF). A deuterium and helium-3 gas-filled glass capsule was imploded with 39 kJ of laser energy from 24 of NIF’s 192 beams. Spectral, spatial, and temporal measurements of the 15-MeV proton product of the {sup 3}He(d,p){sup 4}He nuclear reaction reveal a bright (10{sup 10} protons/sphere), monoenergetic (ΔE/E = 4%) spectrum with a compact size (80 μm) and isotropic emission (∼13% proton fluence variation and <0.4% mean energy variation). Simultaneous measurements of products produced by the D(d,p)T and D(d,n){sup 3}He reactions also show 2 × 10{sup 10} isotropically distributed 3-MeV protons.

  15. « Constituer un sérieux dossier d’archives de la Cité » : le fonds d’archives de la Cité internationale universitaire de Paris

    Directory of Open Access Journals (Sweden)

    Damien Richard

    2012-02-01

    Full Text Available Versées aux Archives nationales en 2009, après un important travail de tri et d’inventaire, les archives de la Cité internationale universitaire de Paris restituent dans toutes ses dimensions l’histoire, depuis sa création en 1920, de cette institution hors du commun. Le patrimoine architectural en représente un pan majeur, eu égard au panorama architectural du XXe siècle que constitue la Cité et aux grands noms qui se sont succédé à la signature des constructions. Mais le fonds met également en avant la vie quotidienne de la Cité, dans ses dimensions les plus joyeuses, par exemple les activités culturelles, comme les plus tragiques, tels les affrontements en factions politiques rivales à la Maison de l’Iran après la révolution khomeiniste. À travers trois exemples, le Collège franco-britannique (1937, la Maison du Brésil (1959 et celle de l’Iran (1969, cet article souhaite montrer la richesse de cette source nouvellement offerte à la recherche.Given to the National Archives in 2005, after an important effort of classifying and listing, the archives of the Cité internationale universitaire de Paris offer a complete account of the history of this most remarkable institution since its creation in 1920. The architectural patrimony is one of its most important aspects, given the architectural roundup of the 20th century displayed by the Cité and the famous architects successively responsible for the construction of its buildings. However the collection also shows everyday life in the Cité in its most joyful aspects, for example the cultural activities, but also its most tragic ones, such as the confrontations between rival political factions at the Iran House after the Khomeinist Revolution. Using three examples, the French-British College (1937, the Brazil House (1959 and the Iran House (1969, this article aims at showing the interest of this source recently open to research.

  16. Modeling the Shock Ignition of a Copper Oxide Aluminum Thermite

    Science.gov (United States)

    Lee, Kibaek; Stewart, D. Scott; Clemenson, Michael; Glumac, Nick; Murzyn, Christopher

    2015-06-01

    An experimental ``striker confinement'' shock compression test was developed in the Glumac-group at the University of Illinois to study ignition and reaction in composite reactive materials. These include thermitic and intermetallic reactive powders. The test places a sample of materials such as a thermite mixture of copper oxide and aluminum powders that are initially compressed to about 80 percent full density. Two RP-80 detonators simultaneously push steel bars into reactive material and the resulting compression causes shock compaction of the material and rapid heating. At that point one observes significant reaction and propagation of fronts. But the fronts are peculiar in that they are comprised of reactive events that can be traced to the reaction/diffusion of the initially separated reactants of copper oxide and aluminum that react at their mutual interfaces that nominally make copper liquid and aluminum oxide products. We discuss our model of the shock ignition of the copper oxide aluminum thermite in the context of the striker experiment and how a Gibbs formulation model, that includes multi-components for liquid and solid phases of aluminum, copper oxide, copper and aluminum oxide can predict the events observed at the particle scale in the experiments. Supported by HDTRA1-10-1-0020 (DTRA), N000014-12-1-0555 (ONR).

  17. Uniaxial backfill block compaction

    International Nuclear Information System (INIS)

    The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

  18. National Ignition Facility site requirements

    International Nuclear Information System (INIS)

    The Site Requirements (SR) provide bases for identification of candidate host sites for the National Ignition Facility (NIF) and for the generation of data regarding potential actual locations for the facilities. The SR supplements the NIF Functional Requirements (FR) with information needed for preparation of responses to queries for input to HQ DOE site evaluation. The queries are to include both documents and explicit requirements for the potential host site responses. The Sr includes information extracted from the NIF FR (for convenience), data based on design approaches, and needs for physical and organization infrastructure for a fully operational NIF. The FR and SR describe requirements that may require new construction or may be met by use or modification of existing facilities. The SR do not establish requirements for NIF design or construction project planning. The SR document does not constitute an element of the NIF technical baseline

  19. The National Ignition Facility project

    Energy Technology Data Exchange (ETDEWEB)

    Paisner, J.A.; Boyes, J.D.; Kumpan, S.A.; Sorem, M.

    1996-06-01

    The Secretary of the U.S. Department of Energy (DOE) commissioned a Conceptual Design Report (CDR) for the National Ignition Facility (NIF) in January 1993 as part of a Key Decision Zero (KD0), justification of Mission Need. Motivated by the progress to date by the Inertial Confinement Fusion (ICF) program in meeting the Nova Technical Contract goals established by the National Academy of Sciences in 1989, the Secretary requested a design using a solid-state laser driver operating at the third harmonic (0.35 {mu}m) of neodymium (Nd) glass. The participating ICF laboratories signed a Memorandum of Agreement in August 1993, and established a Project organization, including a technical team from the Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the Laboratory for Laser Energetics at the University of Rochester. Since then, the authors completed the NIF conceptual design, based on standard construction at a generic DOE Defense Program`s site, and issued a 7,000-page, 27-volume CDR in May 1994. Over the course of the conceptual design study, several other key documents were generated, including a Facilities Requirements Document, a Conceptual Design Scope and Plan, a Target Physics Design Document, a Laser Design Cost Basis Document, a Functional Requirements Document, an Experimental Plan for Indirect Drive Ignition, and a Preliminary Hazards Analysis (PHA) Document. DOE used the PHA to categorize the NIF as a low-hazard, non-nuclear facility. This article presents an overview of the NIF project.

  20. A Micro-Cylindrical Ion Trap (5-CIT) Micro-Mass Spectrometer Instrument System (5-MSIS) for NASA Planetary Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This activity will significantly increase the fidelity of the miniaturized component packaging of the µ-CIT mass spectrometer assembly. Our design approach...

  1. A Micro-Cylindrical Ion Trap (B5-CIT) Micro-Mass Spectrometer Instrument System (B5-MSIS) for NASA Planetary Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This activity will significantly increase the fidelity of the miniaturized component packaging of the μ-CIT mass spectrometer assembly. Our design approach...

  2. Regard noir sur la Cité des Anges : James Ellroy

    Directory of Open Access Journals (Sweden)

    Frédéric SOUNAC

    2010-03-01

    Full Text Available Le mythe de Los Angeles, largement associé à l’immensité de la ville et à la présence en son sein d’Hollywood, est en grande partie une création du roman noir : cité sismique, Sodome moderne, la « Cité des anges » est souvent décrite comme un lieu violent, pulsionnel, où toute tentative de rachat individuel est rendue impossible par l’omniprésence de la corruption. La décadence de la ville-monde, telle qu’elle est analysée de manière résolument pessimiste par le géographe Mike Davis dans Au-delà de Blade Runner, trouve dans les romans de Michael Connelly et de James Ellroy une puissante représentation fictionnelle. Le premier, à travers les errances de son détective Harry Bosch, tient un discours de type élégiaque, tandis que le deuxième, en élaborant une sorte de « réalisme tragique », élève la ville au rang d’allégorie de la Faute et du Mal. L’œuvre d’Ellroy, en particulier, repose sur un arpentage minutieux et obsessionnel des quartiers de Los Angeles, une observation cruelle de sa sociologie et de son histoire, un rapport de haine-amour avec son architecture : le schéma d’enquête, chez lui, relève d’une quête souvent fatale de la mémoire dans une cité que sa rage autodestructrice et ses mutations incessantes vouent à l’amnésie.The myth of Los Angeles, tightly linked to the city’s hugeness and its heart of hearts Hollywood, is to a great extent a creation of the « dark » novel, or « noir ». A sismic territory and modern Sodoma, the so-called « City of Angels » is often depicted as a violent and all impulse driven place, in which the individual yearning for redemption is always destroyed by endemic corruption. The decadent city analyzed in a rather pessimistic way by Mike Davis in his essay Beyond Blade Runner finds in Michael Connelly’s and James Ellroy’s crime fiction a powerful representation. Connelly’s world, with its whimsical main character detective

  3. In vitro and in vivo characterisation of nor-{beta}-CIT: a potential radioligand for visualisation of the serotonin transporter in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, K.A. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden)]|[Kuopio University Hospital, Clinical Physiology, FIN-70210 Kuopio (Finland); Halldin, C. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Hall, H. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Lundkvist, C. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Ginovart, N. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Swahn, C.G. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Farde, L. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden)

    1997-06-10

    Radiolabelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ({beta}-CIT) has been used in clinical studies for the imaging of dopamine and serotonin transporters with single-photon emission tomography (SPET). 2{beta}-Carbomethoxy-3{beta}-(4-iodophenyl)nortropane (nor-{beta}-CIT) is a des-methyl analogue of {beta}-CIT, which in vitro has tenfold higher affinity (IC{sub 50}=0.36 nM) to the serotonin transporter than {beta}-CIT (IC{sub 50}=4.2 nM). Nor-{beta}-CIT may thus be a useful radioligand for imaging of the serotonin transporter. In the present study iodine-125 and carbon-11 labelled nor-{beta}-CIT were prepared for in vitro autoradiographic studies on post-mortem human brain cryosections and for in vivo positron emission tomography (PET) studies in Cynomolgus monkeys. Whole hemisphere autoradiography with [{sup 125}I]nor-{beta}-CIT demonstrated high binding in the striatum, the thalamus and cortical regions of the human brain. Addition of a high concentration (1 {mu}M) of citalopram inhibited binding in the thalamus and the neocortex, but not in the striatum. In PET studies with [{sup 11}C]nor-{beta}-CIT there was rapid uptake of radioactivity in the monkey brain (6% of injected dose at 15 min) and high accumulation of radioactivity in the striatum, thalamus and neocortex. Thalamus to cerebellum and cortex to cerebellum ratios were 2.5 and 1.8 at 60 min, respectively. The ratios obtained with [{sup 11}C]nor-{beta}-CIT were 20%-40% higher than those previously obtained with [{sup 11}C]{beta}-CIT. Radioactivity in the thalamus and the neocortex but not in the striatum was displaceable with citalopram (5 mg/kg). In conclusion, nor-{beta}-CIT binds to the serotonin transporter in the primate brain in vitro and in vivo and has potential for PET and SPET imaging of the serotonin transporter in human brain. (orig.). With 4 figs.

  4. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic...

  5. Analytical model for fast-shock ignition

    OpenAIRE

    S. A. Ghasemi; A. H. Farahbod; Sobhanian, S.

    2014-01-01

    A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI). The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ∼4.5 MeV...

  6. Approach to ignition of tokamak reactors

    International Nuclear Information System (INIS)

    Recent transport modeling results for JET, INTOR, and ETF are reviewed and analyzed with respect to existing uncertainties in the underlying physics, the self-consistency of the very large numerical codes, and the margin for ignition. The codes show ignition to occur in ETF/INTOR-sized machines if empirical scaling can be extrapolated to ion temperatures (and beta values) much higher than those presently achieved, if there is no significant impurity accumulation over the first 7 s, and if the known ideal and resistive MHD instabilities remain controllable for the evolving plasma profiles during ignition startup

  7. « Récit concentrationnaire » et « prose d’idées »

    Directory of Open Access Journals (Sweden)

    Lucie Bertrand

    2008-03-01

    Full Text Available Les écrits des rescapés des camps de concentration nazis sont regroupés dans une catégorie très floue et très englobante sous le nom de « récits concentrationnaires ». Cet appellatif, qui distingue ces œuvres qui ont en partage une vocation testimoniale et un ancrage historique commun, porte pourtant préjudice à certaines d’entre elles qui, possédant des qualités littéraires réelles et des objectifs didactiques cruciaux, voient leur qualités déterminantes étouffées par un tel mode de classification. C’est pourquoi, en nous appuyant essentiellement sur l’une de ces œuvres, L’Espèce humaine de Robert Antelme, nous aimerions nous demander si l’appellatif de « prose d’idées » n’est pas susceptible d’être appliqué à ces œuvres pour que soient perçues leurs spécificités. Et si, en retour, celles-ci ne permettent pas d’offrir un regard neuf sur la notion de « prose d’idées ».The french word used to group together nazi’s camps survivor’s writings is detrimental to some of them which hinge on the same fundamental features. As a matter of fact, the appellative “récit concentrationnaire” gathers all those writings on the basis of their testimonial and historical dimension. As a consequence, writings which share those features but possess crucial didactic goals and a deep reflection on how to tell the unspeakable are not acknowledged for their specificities. Relying on Robert Antelme’s Espèce humaine as an example of this kind of writings, we aim at questioning the traditional classification. We consider the “prose d’idées” as a good mean to gain our aim: may be this expression could fit the writings we deal with. And may be, in return, asking this question can lead us to approach this latter from a new angle.

  8. Una meditaciòn ou le récit d’un « arrangeur »

    OpenAIRE

    Boyer, Denise

    2014-01-01

    Una meditación est le seul roman de Juan Benet doté d'un narrateur intradiégétique unique : nulle autre voix n'intervient donc pour « compléter » ou « corriger » son récit. Qui plus est Juan Benet a pris soin d'expliquer que ce narrateur « ne dit pas la vérité », qu'il « se contredit », et qu'il est « l'auteur ou l'instigateur de plusieurs des drames » qu'il raconte. La tâche du lecteur s'apparente donc à une gageure : comment s'orienter en effet dans un récit mensonger, et de surcroît extrêm...

  9. In vivo imaging of dopamine transporter function in rat striatum using pinhole SPECT and 123I-beta-CIT coregistered with small animal MRI

    CERN Document Server

    Dierkes, K

    2001-01-01

    The aim of this study was to establish in vivo imaging of dopamine transporter function in a small animal model of Parkinson's disease using pinhole SPECT and 123I labeled beta-CIT. Since functional imaging of small animals can hardly be interpreted without localization to related anatomical structures, MRI-SPECT coregistration secondly was established as an inexpensive tool for in vivo monitoring of physiological and pathological alterations in striatal dopamine transporters using beta-CIT as an specific radionuclear ligand.

  10. Ignition of deuterium based fuel cycles in a high beta system

    International Nuclear Information System (INIS)

    A steady state self-consistent plasma modeling applied to a system having close to unity, such as FRC or like, is found to be quite effective in solving the problems independently of any anomalous process and proves the existence of ignited state of deuterium based fuel cycles. The temperature ranges that the plasma falls into ignited state are obtained as a function of relative feeding rates of tritium and 3He to deuterium's. We find pure DD cycle will not ignite so that 3He or/and tritium must be added as catalyzer to achieve ignition. Standing on the points to construct a cleaner system yielding smaller amount of 14 MeV neutrons and to burn the fuel in steady state for long periods of time, we have confirmed superiority of the complex composed of the master reactor of 3He-Cat.D cycle (catalyzed DD cycle reinjecting only fusion produced 3He) and the satellite reactor of 3He enriched D3He cycle. In case storage of tritium for 3He by β- decay is turned out not to be allowed environmentally, we may utilize conventional catalyzed DD cycle although 14 MeV neutron yields will be increased by 35 % over the complex. It is demonstrated that advanced fuel cycle reactors can be very simple in constructions and compact in size such that the field strength and the plasma volume of the order of JT-60's may be enough for 1000 MW power plant. (author)

  11. Development of a simulation model for compression ignition engine running with ignition improved blend

    OpenAIRE

    Sudeshkumar Ponnusamy Moranahalli; Devaradjane Gopalakrishnan

    2011-01-01

    Department of Automobile Engineering, Anna University, Chennai, India. The present work describes the thermodynamic and heat transfer models used in a computer program which simulates the diesel fuel and ignition improver blend to predict the combustion and emission characteristics of a direct injection compression ignition engine fuelled with ignition improver blend using classical two zone approach. One zone consists of pure air called non burning zone and other zone consist of fuel a...

  12. Prospects of lean ignition with the quarter wave coaxial cavity igniter

    Science.gov (United States)

    Pertl, Franz Andreas Johannes

    New ignition sources are needed to operate the next generation of lean high efficiency internal combustion engines. A significant environmental and economic benefit could be obtained from these lean engines. Toward this goal, the quarter wave coaxial cavity resonator, QWCCR, igniter was examined. A detailed theoretical analysis of the resonator was performed relating geometric and material parameters to performance characteristics, such as resonator quality factor and developed tip electric field. The analysis provided for the construction and evaluation of a resonator for ignition testing. The evaluation consisted of ignition tests with liquefied-petroleum-gas (LPG) air mixtures of varying composition. The combustion of these mixtures was contained in a closed steel vessel with a precombustion pressure near one atmosphere. The resonator igniter was fired in this vessel with a nominal 150 W microwave pulse of varying duration, to determine ignition energy limits for various mixtures. The mixture compositions were determined by partial pressure measurement and the ideal gas law. Successful ignition was determined through observation of the combustion through a view port. The pulse and reflected microwave power were captured in real time with a high-speed digital storage oscilloscope. Ignition energies and power levels were calculated from these measurements. As a comparison, these ignition experiments were also carried out with a standard non-resistive spark plug, where gap voltage and current were captured for energy calculations. The results show that easily ignitable mixtures around stoichiometric and slightly rich compositions are ignitable with the QWCCR using the similar kinds of energies as the conventional spark plug in the low milli-Joule range. Energies for very lean mixtures could not be determined reliably for the QWCCR for this prototype test, but could be lower than that for a conventional spark. Given the capability of high power, high energy delivery

  13. High-resolution CO observation of the carbon star CIT 6 revealing the spiral structure and a nascent bipolar outflow

    CERN Document Server

    Kim, Hyosun; Hirano, Naomi; Zhao-Geisler, Ronny; Trejo, Alfonso; Yen, Hsi-Wei; Taam, Ronald E; Kemper, Francisca; Kim, Jongsoo; Byun, Do-Young; Liu, Tie

    2015-01-01

    CIT 6 is a carbon star in the transitional phase from the asymptotic giant branch (AGB) to the protoplanetary nebulae (pPN). Observational evidences of two point sources in the optical, circumstellar arc segments in an HC$_3$N line emission, and a bipolar nebula in near-infrared provide strong support for the presence of a binary companion. Hence, CIT 6 is very attractive for studying the role of companions in the AGB-pPN transition. We have carried out high resolution $^{12}$CO $J=2-1$ and $^{13}$CO $J=2-1$ observations of CIT 6 with the Submillimeter Array combined with the Submillimeter Telescope (single-dish) data. The $^{12}$CO channel maps reveal a spiral-shell pattern connecting the HC$_3$N segments in a continuous form, and an asymmetric outflow corresponding to the near-infrared bipolar nebula. Rotation of the $^{12}$CO channel peak position may be related to the inner spiral winding and/or the bipolar outflow. An eccentric orbit binary is suggested for the presences of an anisotropic mass loss to th...

  14. Relationship between striatal [123I]β-CIT binding and four major clinical signs in Parkinson's disease

    International Nuclear Information System (INIS)

    We investigated the correlation between clinical severity and striatal [123I]β-CIT binding in 12 patients with Parkinson's Disease (PD: 6 men and 6 women, age: 65±7 years, Hoehn-Yahr stage: 1 to 3). The clinical severity of PD patients was measured with the Unified Parkinson's Disease Rating Scale (UPDRS) after withdrawal of antiparkinsonian medication at least 12 hours before assessment. [123I]β-CIT binding in the caudate and putamen was measured at 3 hours [V''3 (day 1)], and at 24 hours [V''3 (day 2)] after tracer injection with small square ROIs. The specific striatal uptake index (day 2) was calculated with large square ROIs that encompassed the whole striatum. The best correlation (r=-0.82, p3 (day 2) and the motor UPDRS scores. When the motor UPDRS scores were divided into four subscales, bradykinesia was the only sign that correlated significantly with putamenal V''3 (day 2) (r=-0.81, p123I]β-CIT SPECT is a useful marker of disease severity in PD with potential utility in the serial monitoring of disease progression. (author)

  15. SPECT imaging of dopamine and serotonin transporters with [123I]β-CIT. Binding kinetics in the human brain

    International Nuclear Information System (INIS)

    Single photon emission computerized tomography (SPECT) studies in non-human primates have previously shown that the cocaine derivative [123I]-2-β-carbomethoxy-3-β-(4-iodophenyl)-tropane ([123I]β-CIT) labels dopamine transporters in the striatum and serotonin transporters in the hypothalamus-midbrain area. Here, we report on the regional kinetic uptake of [123I]β-CIT in the brain of 4 normal volunteers and 2 patients with Parkinson's disease. In healthy subjects striatal activity increased slowly to reach peak values at about 20 hours post injection. In the hypothalamus-midbrain area peak activities were observed at about 4 hours with a slow decrease thereafter. Low activity was observed in cortical and cerebellar areas. The striatal to cerebellar ratio was about 4 after 5 hours and 9 after 20 hours. In 2 patients with idiopathic Parkinson's disease striatal activity was markedly decreased while the activity in hypothalamus-midbrain areas was only diminished. Uptake into cortical and cerebellar areas appeared to be unchanged in Parkinson's disease. Consequently, in Parkinson's disease the striatal to cerebellar ratio was decreased to values around 2.5 after 20 hours. These preliminary methodological studies suggest that [123I]β-CIT is a useful SPECT ligand for studying dopamine and possibly also serotonin transporters in the living human brain

  16. Compact boson stars

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Betti [School of Engineering and Science, Jacobs University, Postfach 750 561, D-28725 Bremen (Germany); Kleihaus, Burkhard; Kunz, Jutta [Institut fuer Physik, Universitaet Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Schaffer, Isabell, E-mail: i.schaffer@jacobs-university.de [School of Engineering and Science, Jacobs University, Postfach 750 561, D-28725 Bremen (Germany)

    2012-07-24

    We consider compact boson stars that arise for a V-shaped scalar field potential. They represent a one parameter family of solutions of the scaled Einstein-Gordon equations. We analyze the physical properties of these solutions and determine their domain of existence. Along their physically relevant branch emerging from the compact Q-ball solution, their mass increases with increasing radius. Employing arguments from catastrophe theory we argue that this branch is stable, until the maximal value of the mass is reached. There the mass and size are on the order of magnitude of the Schwarzschild limit, and thus the spiraling respectively oscillating behaviour, well known for compact stars, sets in.

  17. O papel do CITS1 na política de desenvolvimento tecnológico no Paraná The role of CITS on the policy on technological development in Paraná state

    Directory of Open Access Journals (Sweden)

    Walter Tadahiro Shimajv

    2005-12-01

    Full Text Available Analisam-se as implicações da produção de software no Paraná. Como produção de bem intangível, há contribuições para a expansão do Sistema Setorial de Inovação. O foco da análise é o Centro Internacional de Tecnologia de Software e sua trajetória natural em direção à capacitação para a inovação radical de forma híbrida. Discute-se a integração entre os conceitos de Sistema Nacional de Inovação e Triple Helix (TH e apresenta-se sua evolução no Brasil e no Paraná (Sistema Local. O software é a pura expressão do atual paradigma tecnológico. É necessária uma forte política de desenvolvimento centrada nas tecnologias de informação, em função do papel revolucionário exercido nas economias centrais. O CITS se encaixa perfeitamente nessa nova dinâmica, estabelecendo uma estratégia clara de aquisição de competências e construindo uma rede de conhecimento nos níveis micro, meso e macroeconômico. A evolução da fase atual do CITS implicará uma forte ação da TH.This article analyses the implications of the software production in Paraná state, which strongly contributes to the expansion of the Sectoral Innovation System. The focus is on CITS - Centro Internacional de Tecnologia de Software (International Centre of Software Technology and its natural trajectory towards the capability for a radical innovation in a hybrid way. It discusses the integration between the concepts of the National System of Innovation and the Triple Helix (TH and presents its evolution in Brazil, more specifically in Paraná State (Local System. As a pure expression of the current technological paradigm, the software implies a strong policy on development centred on the generic information technologies because of the revolutionary role that such technologies have exercised on central economies. CITS perfectly fits this new dynamics, establishing a clear strategy for acquisition of competencies and building a network of knowledge

  18. Ignition properties of nuclear grade activated carbons

    International Nuclear Information System (INIS)

    The ignition property of new activated carbons used in air cleaning systems of nuclear facilities has been evaluated in the past, however very little information has been generated on the behavior of aged, weathered carbons which have been exposed to normal nuclear facility environment. Additionally the standard procedure for evaluation of ignition temperature of carbon is performed under very different conditions than those used in the design of nuclear air cleaning systems. Data were generated evaluating the ageing of activated carbons and comparing their CH3131I removal histories to their ignition temperatures. A series of tests were performed on samples from one nuclear power reactor versus use time, a second series evaluated samples from several plants showing the variability of atmospheric effects. The ignition temperatures were evaluated simulating the conditions existing in nuclear air cleaning systems, such as velocity, bed depth, etc., to eliminate potential confusion resulting from artifically set current standard conditions

  19. Fast ignition by quasimonoenergetic ion beams

    Directory of Open Access Journals (Sweden)

    Honrubia J.J.

    2013-11-01

    Full Text Available The potential of quasimonoenergetic ion beams for fast ignition (FI of fusion targets is investigated. Lithium, carbon, aluminium and vanadium ions have been considered here to determine the optimal kinetic energy for each ion type. Our calculations show that the ignition energies of those beams impinging on a standard fuel configuration are similar. However, they are obtained for very different ion energies. Assuming that the ions can be focused onto 10 μm spots, a new irradiation scheme that reduces substantially the ignition energies is proposed. The combination of using intermediate ions, such as 5.5 GeV vanadium, and the new irradiation scheme allows one to reduce the number of ions required for ignition by roughly three orders of magnitude when compared with the standard proton FI scheme.

  20. Plasma igniter for internal-combustion engines

    Science.gov (United States)

    Breshears, R. R.; Fitzgerald, D. J.

    1978-01-01

    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  1. MECHANISM ON DISTRIBUTION OF PILOT FUEL SPRAY AND COMPRESSING IGNITION IN PREMIXED NATURAL GAS ENGINE IGNITED BY PILOT DIESEL

    Institute of Scientific and Technical Information of China (English)

    Yao Chunde; Yao Guangtao; Song Jinou; Wang Yinshan

    2005-01-01

    Numerical simulations of pilot fuel spray and compressing ignition for pre-mixed natural gas ignited by pilot diesel are described. By means of these modeling, the dual fuel and diesel fuel ignition mechanism of some phenomena investigated on an optional engine by technology of high-speed CCD is analyzed. It is demonstrated that the longer delay of ignition in dual fuel engine is not mainly caused by change of the mixture thermodynamics parameters. The analysis results illustrate that the ignition of pre-mixed natural gas ignited by pilot diesel taking place in dual fuel engine is a process of homogenous charge compression ignition.

  2. Swiss Science Festival - Science et Cité Science - It's magic!

    CERN Multimedia

    2001-01-01

    CERN's new antimatter factory, the Antiproton Decelerator (AD), will allow precision studies of antihydrogen. From Saturday 5 May for a week in ten Swiss towns, the 'Science et Cité' Festival will be bringing science to the public. The festival aims to be a bridge between the concerns of the public at large and those of scientists, so naturally CERN is involved. The Laboratory is organising special visits on the theme of antimatter. Following a presentation by Rolf Landua, spokesman of the ATHENA collaboration, visitors will discover two machines indispensable for the study of antimatter - LEIR, which as LEAR was where the first atoms of antihydrogen were created, and the new antimatter factory, the Antiproton Decelerator, AD. As well as these visits, CERN guides will become show people on the stand 'Magicians? Physicists!' at the old SIP building, where the majority of the Geneva events will take place. Disguised as magicians, our guides will amaze and astound their audience with a series of rema...

  3. Cristine de Pizan e le emozioni per la Cità des Dames

    Directory of Open Access Journals (Sweden)

    Angela Giallongo

    2011-06-01

    Full Text Available L’interesse storico per le emozioni spinge ad interrogarsi sul loro ruolo nelle utopie femminili alla fine del medioevo. Una fonte centrale su questo tema è l’opera illustrata la Cité des Dames (1405 di C. de Pizan (1365-1430. Gli studi di B.H. Rosenwein, W. Reddie e K.Oatley forniscono categorie interpretative psico-sociali (comunità emotive e regime emotivo utili per connettere l’idea di utopia, valori emotivi e rapporti interpersonali fra i sessi. La problematicizzazione, suggerita da Rosenwein, della comunità immaginata come comunità emotiva aiuta a identificare i modi di sentire rifiutati e quelli privilegiati per l’espressione del senso di sé e per la costruzione della città ideale, offerta alle donne di tutte le classi sociali.In conclusione, l’analisi qualitativa dell’opera della de Pizan focalizza l’uso formativo delle immagini mitiche, l’esperienza dell’autrice, contestualizzata nel periodo, e i significati culturali attribuiti alle “emozioni”.

  4. Confinement scaling and ignition in tokamaks

    International Nuclear Information System (INIS)

    A drift wave turbulence model is used to compute the scaling and magnitude of central electron temperature and confinement time of tokamak plasmas. The results are in accord with experiment. Application to ignition experiments shows that high density (1 to 2) . 1015 cm-3, high field, B/sub T/ > 10 T, but low temperature T approx. 6 keV constitute the optimum path to ignition

  5. Loss/gain on ignition test report

    International Nuclear Information System (INIS)

    Document provides the results of tests done on Product Cans from the HC-21C sludge stabilization process. Tests included running a simulated Thermogravimetric Analysis, TGA, on the processed material that have received Loss On Ignition (LOI) sample results that show a gain on ignition or a high LOI and reprocessing product cans with high LOIs. Also, boat material temperatures in the furnace were tracked during the testing

  6. Laser-plasma interactions for fast ignition

    OpenAIRE

    Kemp, A. J.; Fiuza, F.; Debayle, A.; Johzaki, T.; Mori, W. B.; P.K. Patel; Sentoku, Y.; Silva, L. O.

    2014-01-01

    In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multi-dimensi...

  7. Dynamic Regime of Ignition of Solid Propellant

    Directory of Open Access Journals (Sweden)

    Zolotorev Nikolay

    2016-01-01

    Full Text Available This article presents a dynamic regime of exposure of the radiant flux on the sample of gun-cotton. Obtained time the ignition of gun-cotton in the heating conditions of increasing heat flux in the range from 0.2 W/cm2 to 22 W/cm2. A comparison of the delay times of the ignition when heated variable and constant heat flux.

  8. Chaotic Combustion in Spark Ignition Engines

    OpenAIRE

    Wendeker, M.; Czarnigowski, J.; Litak, G.; Szabelski, K.

    2002-01-01

    We analyse the combustion process in a spark ignition engine using the experimental data of an internal pressure during the combustion process and show that the system can be driven to chaotic behaviour. Our conclusion is based on the observation of unperiodicity in the time series, suitable stroboscopic maps and a complex structure of a reconstructed strange attractor. This analysis can explain that in some circumstances the level of noise in spark ignition engines increases considerably due...

  9. Thermonuclear ignition in the next generation tokamaks

    International Nuclear Information System (INIS)

    The extrapolation of experimental rules describing energy confinement and magnetohydrodynamic - stability limits, in known tokamaks, allow to show that stable thermonuclear ignition equilibria should exist in this configuration, if the product aBtx of the dimensions by a magnetic-field power is large enough. Quantitative application of this result to several next-generation tokamak projects show that those kinds of equilibria could exist in such devices, which would also have enough additional heating power to promote an effective accessible ignition

  10. Review of progress in Fast Ignition

    International Nuclear Information System (INIS)

    Marshall Rosenbluth's extensive contributions included seminal analysis of the physics of the laser-plasma interaction and review and advocacy of the inertial fusion program. Over the last decade he avidly followed the efforts of many scientists around the world who have studied Fast Ignition, an alternate form of inertial fusion. In this scheme, the fuel is first compressed by a conventional inertial confinement fusion driver and then ignited by a short (∼10 ps) pulse, high-power laser. Due to technological advances, such short-pulse lasers can focus power equivalent to that produced by the hydrodynamic stagnation of conventional inertial fusion capsules. This review will discuss the ignition requirements and gain curves starting from simple models and then describe how these are modified, as more detailed physics understanding is included. The critical design issues revolve around two questions: How can the compressed fuel be efficiently assembled? And how can power from the driver be delivered efficiently to the ignition region? Schemes to shorten the distance between the critical surface where the ignitor laser energy is nominally deposited and the ignition region will de discussed. The current status of Fast Ignition research is compared with our requirements for success. Future research directions will also be outlined

  11. Infrared thermographic study of laser ignition

    International Nuclear Information System (INIS)

    Pyrotechnic ignition has been studied in the past by making a limited number of discrete temperature-time observations during ignition. Present-day infrared scanning techniques make it possible to record thermal profiles, during ignition, with high spacial and temporal resolution. Data thus obtained can be used with existing theory to characterize pyrotechnic materials and to develop more precise kinetic models of the ignition process. Ignition has been studied theoretically and experimentally using various thermal methods. It has been shown that the whole process can, ideally, be divided into two stages. In the first stage, the sample pellet behaves like an inert body heated by an external heat source. The second stage is governed by the chemical reaction in the heated volume produced during the first stage. High speed thermographic recording of the temperature distribution in the test sample during laser ignition makes it possible to calculate the heat content at any instant. Thus, one can actually observe laser heating and the onset of self-sustained combustion in the pellet

  12. Ignition Delay Studies on Hypergolic Fuel Grains

    Directory of Open Access Journals (Sweden)

    S. R. Jain

    1988-07-01

    Full Text Available The ignition delays of several solid hypergolic fuel compositions, casted using various polymeric binders, or as melts, have been determined with fuming nitric acid as oxidizer. The ignition delays of various hypergolic fuel compositions increase drasticaliy on casting with binders like. carboxyl or hydroxyl termninated polybutadiene. Fuel grains cast using some newly syhthesised epoxy  resins with other ingrcdients, such as curing agent, magnesium powder and fuel, have short ignition delays of the order of 200 ms, and also good mechanical strength. Increasing the amount of binder in the composition retards the hypergolicity of the rain. Similar studies have been made on melt-cast systems using low melting hypergolic fuels for casting fuel powders. The ignition delays of the melt-cast grains, are longer than those determined taking the composition in the powder form. The effect of highly hypergolic additives, and metal powders, on the ignition delay of the cast compositions has been determined. Grains having good mechanical strength and short ignition delays have been obtained by optimising the fuel grain composition.

  13. One-step high-radiochemical-yield synthesis of [18F]FP-CIT using a protic solvent system

    International Nuclear Information System (INIS)

    Although [18F] fluoropropylcarbomethoxyiodophenylnortropane (FP-CIT) is a promising radiopharmaceutical for dopamine transporter imaging, it has not been used for clinical studies because of low radiochemical yield. The purpose of our study was to develop a new radiochemistry method using a protic solvent system to obtain a high radiochemical yield of [18F]FP-CIT in single-step manual and automatic preparation procedures. [18F]F- was trapped on a QMA Sep-Pak cartridge or PS-HCO3 cartridge and eluted with Cs2CO3/K222 buffer or TBAHCO3, respectively, or 8 μl of TBAOH was added directly to [18F]F-/H218O solution in a reactor without using a cartridge. After drying, [18F] fluorination was performed with 2-6 mg of mesylate precursor, 100 μl of CH3CN and 500 μl of t-BuOH at 50-120oC for 5-30 min, followed by high-performance liquid chromatography (HPLC) purification to obtain the final product. For comparison, the same procedure was performed with a tosylate precursor. Manual synthesis gave a decay-corrected radiochemical yield of 52.2±4.5%, and optimal synthesis conditions were as follows: TBAOH addition, 4 mg of precursor, 100oC and 20 min of [18F] fluorination (n=3). We obtained low radiochemical yields of [18F]FP-CIT with carbonate elution systems such as Cs2CO3 or TBAHCO3. We also developed an automatic synthesis method based on manual synthesis results. In automatic production, we obtained a decay-corrected radiochemical yield of 35.8±5.2% after HPLC purification, and we did not have any synthesis failures (n=14). Here, we describe our new method for the synthesis of [18F]FP-CIT using a protic solvent system. This method gave a high radiochemical yield with high reproducibility and might enable [18F]FP-CIT to be used clinically and commercially

  14. Roller compaction of theophylline

    OpenAIRE

    Hadzovic, Ervina

    2008-01-01

    1. Summary Direct compaction requires a very good flowability and compressibility of the materials. Those parameters become even more critical if the formulation contains large amount of active substance. To overcome these problems, several alternatives have been used. Roller compaction is a very attractive technology in the pharmaceutical industry. It is a fast and efficient way of producing granules, especially suitable for moisture sensitive materials. The intention of this work was to ...

  15. Ignition length study of jp-8 + 100 in a supersonic duct

    Science.gov (United States)

    Bateup, M. L.

    2016-07-01

    In scramjets, hydrocarbon fuels are being considered for their endothermic potential and for use in flights where compact, volume critical designs are required at flight speeds at Mach 5+. Long-chain hydrocarbon (LCHC) fuels, like aviation kerosene, have handling and storage advantages over hazardous and volatile fuels, like hydrogen, that are more aligned with current flight systems. This research investigates the conditions under which kerosene fuel (JP-8 + 100) may be used in a supersonic duct at a hypervelocity impulse facility. Experimental data on kerosene ignition lengths for temperatures in the range 1100-1550 K, pressure of 1 atm, and equivalence ratios of 0.2-2.5 are compared with ignition delay correlations from literature.

  16. No significant effects of single intravenous, single oral and subchronic oral administration of acetylcholinesterase inhibitors on striatal [{sup 123}I]FP-CIT binding in rats

    Energy Technology Data Exchange (ETDEWEB)

    Knol, R.J.J.; Booij, J. [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands); Graduate School of Neurosciences, Amsterdam (Netherlands); Bruin, K. de; Eck-Smit, B.L.F. van [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands)

    2008-03-15

    [{sup 123}I]FP-CIT SPECT is a valuable diagnostic tool to discriminate Lewy body dementia from Alzheimer's dementia. To date, however, it is uncertain whether the frequently used acetylcholinesterase inhibitors (AChEIs) by demented patients, have an effect on [{sup 123}I]FP-CIT binding to dopamine transporters (DATs). Earlier animal studies showed a decline of DAT availability after acute intravenous injection of AChEIs. The aim of this study was to investigate effects of single intravenous, single oral and subchronic oral administration of AChEIs on DAT availability in the rat brain as measured by [{sup 123}I]FP-CIT. Biodistribution studies were performed in Wistar rats (n = 5-16 per group). Before [{sup 123}I]FP-CIT injection, rats were injected intravenously with a single dose of the AChEI rivastigmine (2.5 mg/kg body weight) or donepezil (0.5 mg/kg), the DAT-blocker methylphenidate (10 mg/kg) or saline. A second group was orally treated with a single dose of rivastigmine or donepezil (2.5 mg/kg), methylphenidate (10 mg/kg) or saline before injection of [{sup 123}I]FP-CIT. Studies were also performed in rats that were orally treated during 14 consecutive days with either rivastigmine (1 mg/kg daily), donepezil (1.5 mg/kg daily), methylphenidate (2.5 mg/kg) or saline. Brain parts were assayed in a gamma counter, and specific striatum/cerebellum ratios were calculated for the [{sup 123}I]FP-CIT binding to DATs. No significant effects of either single intravenous, single oral or subchronic oral administration of AChEIs on striatal FP-CIT binding could be detected. Single pretreatment with methylphenidate resulted in an expected significantly lower striatal FP-CIT binding. We conclude that in rats, single intravenous and single or subchronic oral administration of the tested AChEIs does not lead to an important alteration of [{sup 123}I]FP-CIT binding to striatal DATs. Therefore, it is unlikely that these drugs will induce large effects on the interpretation of

  17. No significant effects of single intravenous, single oral and subchronic oral administration of acetylcholinesterase inhibitors on striatal [123I]FP-CIT binding in rats

    International Nuclear Information System (INIS)

    [123I]FP-CIT SPECT is a valuable diagnostic tool to discriminate Lewy body dementia from Alzheimer's dementia. To date, however, it is uncertain whether the frequently used acetylcholinesterase inhibitors (AChEIs) by demented patients, have an effect on [123I]FP-CIT binding to dopamine transporters (DATs). Earlier animal studies showed a decline of DAT availability after acute intravenous injection of AChEIs. The aim of this study was to investigate effects of single intravenous, single oral and subchronic oral administration of AChEIs on DAT availability in the rat brain as measured by [123I]FP-CIT. Biodistribution studies were performed in Wistar rats (n = 5-16 per group). Before [123I]FP-CIT injection, rats were injected intravenously with a single dose of the AChEI rivastigmine (2.5 mg/kg body weight) or donepezil (0.5 mg/kg), the DAT-blocker methylphenidate (10 mg/kg) or saline. A second group was orally treated with a single dose of rivastigmine or donepezil (2.5 mg/kg), methylphenidate (10 mg/kg) or saline before injection of [123I]FP-CIT. Studies were also performed in rats that were orally treated during 14 consecutive days with either rivastigmine (1 mg/kg daily), donepezil (1.5 mg/kg daily), methylphenidate (2.5 mg/kg) or saline. Brain parts were assayed in a gamma counter, and specific striatum/cerebellum ratios were calculated for the [123I]FP-CIT binding to DATs. No significant effects of either single intravenous, single oral or subchronic oral administration of AChEIs on striatal FP-CIT binding could be detected. Single pretreatment with methylphenidate resulted in an expected significantly lower striatal FP-CIT binding. We conclude that in rats, single intravenous and single or subchronic oral administration of the tested AChEIs does not lead to an important alteration of [123I]FP-CIT binding to striatal DATs. Therefore, it is unlikely that these drugs will induce large effects on the interpretation of [123I]FP-CIT SPECT scans in routine clinical

  18. Aerospace Laser Ignition/Ablation Variable High Precision Thruster

    Science.gov (United States)

    Campbell, Jonathan W. (Inventor); Edwards, David L. (Inventor); Campbell, Jason J. (Inventor)

    2015-01-01

    A laser ignition/ablation propulsion system that captures the advantages of both liquid and solid propulsion. A reel system is used to move a propellant tape containing a plurality of propellant material targets through an ignition chamber. When a propellant target is in the ignition chamber, a laser beam from a laser positioned above the ignition chamber strikes the propellant target, igniting the propellant material and resulting in a thrust impulse. The propellant tape is advanced, carrying another propellant target into the ignition chamber. The propellant tape and ignition chamber are designed to ensure that each ignition event is isolated from the remaining propellant targets. Thrust and specific impulse may by precisely controlled by varying the synchronized propellant tape/laser speed. The laser ignition/ablation propulsion system may be scaled for use in small and large applications.

  19. Antiproton fast ignition for inertial confinement fusion

    International Nuclear Information System (INIS)

    With 180 MJ/microg, antiprotons offer the highest stored energy per unit mass of any known entity. The use of antiprotons to promote fast ignition in an inertial confinement fusion (ICF) capsule and produce high target gains with only modest compression of the main fuel is investigated. Unlike standard fast ignition where the ignition energy is supplied by energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. This can be considered in-situ fast ignition as it obviates the need for the external injection of the ignition energy. In the first of two candidate schemes, the antiproton package is delivered by a low-energy ion beam. In the second, autocatalytic scheme, the antiprotons are preemplaced at the center of the capsule prior to compression. In both schemes, the author estimates that ∼1012 antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition within the ignitor zone. In addition to eliminating the need for a second, energetic fast laser and vulnerable final optics, this scheme would achieve central ignition without reliance on laser channeling through halo plasma or Hohlraum debris. However, in addition to the practical difficulties of storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a speculative scheme is the ultimate efficiency of antiproton production in an external, optimized facility. Estimates suggest that the electrical wall plug energy per pulse required for the separate production of the antiprotons is of the same order as that required for the conventional slow compression driver

  20. Spontaneously Igniting Hybrid Fuel-Oxidiser Systems

    Directory of Open Access Journals (Sweden)

    S. R. Jain

    1995-01-01

    Full Text Available After briefly outlining the recent developments in hybrid rockets, the work carried out by the author on self-igniting (hypergolic solid fuel-liquid oxidiser systems has been reviewed. A major aspect relates to the solid derivatives of hydrazines, which have been conceived as fuels for hybrid rockets. Many of these N-N bonded compounds ignite readily, with very short ignition delays, on coming into contact with liquid oxidisers, like HNO/sub 3/ and N/sub 2/ O/sub 4/. The ignition characteristics have been examined as a function of the nature of the functional group in the fuel molecule, in an attempt to establish a basis for the hypergolic ignition in terms of chemical reactivity of the fuel-oxidiser combination. Important chemical reactions occurring in the pre-ignition stage have been identified by examining the quenched reaction products. Hybrid systems exhibiting synergistic hypergolicity in the presence of metal powders have investigated. An estimation of the rocket performance parameters, experimental determination of the heats of combustion in HNO/sub 3/, thermal decomposition characteristics, temperature profile by thin film thermometry and product identification by the rapid scan FT-IR, are among the other relevant studies made on these systems. A significant recent development has been the synthesis of new N-N bonded viscous binders, capable of rataining the hypergolicity of the fuel powders embedded therein as well as providing the required mechanical strength to the grain. Several of these resins have been characterised. Metallised fuel composites of these resins having high loading of magnesium are found to have short ignition delays and high performance parameters.

  1. Recent developments in ignition target design for the National Ignition Facility

    International Nuclear Information System (INIS)

    Work on design of ignition targets for the National Ignition Facility (NIF) has progressed in three areas. First, hohlraums have been re-optimized taking advantage of improvements in efficiency in several areas: use of high albedo material mixtures in the hohlraum wall; optimizing the laser entrance hole; optimizing the case-to-capsule ratio; and taking advantage of increased efficiency of longer pulses. These changes, in combination, allow for the possibility of quite high yields (∼100MJ), gains (>40) and significantly more margin for ignition on NIF. Second, work has continued on specifications for target fabrication. Third, detailed design and analysis has been done on targets for the commissioning phase of NIF, when only 96 beams are available. We find excellent hydrodynamic similarity is possible with sub-scale cryogenic targets. These targets can be used to test all of the physics of full-scale ignition targets in detail except, perhaps, for ignition itself. (author)

  2. Le récit dans l’image : séquence, intrigue et configuration

    Directory of Open Access Journals (Sweden)

    Raphaël Baroni

    2011-03-01

    Full Text Available

    Résumé: Dans cet article sera interrogée la manière dont l’image fixe est capable de représenter le flux temporel, ce qui représente, on le sait, un trait définitoire essentiel de la narrativité. A cette question, qui nous obligera à invoquer la collaboration d’un interprète construisant un parcours de lecture dans, entre ou au-delà des images fixes, s’ajoutera celle, plus complexe, de savoir quel type de temporalité sera produite par le récit en image. On commencera donc par rappeler que le récit est, par définition, non seulement la représentation séquentielle d’une séquence d’événements, mais que cette transformation est susceptible s’insérer dans une intrigue. Ici encore, l’intrigue peut être prise dans deux sens opposés suivant que l’on considère cette dernière comme une représentation intrigante orientant la réception en direction d’un dénouement incertain, ou alors comme une configuration narrative conférant sens et unité à l’événement représenté. Différents exemples tirés du roman graphique Watchmen serviront à illustrer ces différentes modalités de la narrativité iconique, qui fonctionnent souvent de manière conjointe.

     

  3. Dark Matter Ignition of Type Ia Supernovae.

    Science.gov (United States)

    Bramante, Joseph

    2015-10-01

    Recent studies of low redshift type Ia supernovae (SN Ia) indicate that half explode from less than Chandrasekhar mass white dwarfs, implying ignition must proceed from something besides the canonical criticality of Chandrasekhar mass SN Ia progenitors. We show that 1-100 PeV mass asymmetric dark matter, with imminently detectable nucleon scattering interactions, can accumulate to the point of self-gravitation in a white dwarf and collapse, shedding gravitational potential energy by scattering off nuclei, thereby heating the white dwarf and igniting the flame front that precedes SN Ia. We combine data on SN Ia masses with data on the ages of SN Ia-adjacent stars. This combination reveals a 2.8σ inverse correlation between SN Ia masses and ignition ages, which could result from increased capture of dark matter in 1.4 vs 1.1 solar mass white dwarfs. Future studies of SN Ia in galactic centers will provide additional tests of dark-matter-induced type Ia ignition. Remarkably, both bosonic and fermionic SN Ia-igniting dark matter also resolve the missing pulsar problem by forming black holes in ≳10  Myr old pulsars at the center of the Milky Way. PMID:26551803

  4. Analytical model for fast-shock ignition

    Directory of Open Access Journals (Sweden)

    S. A. Ghasemi

    2014-07-01

    Full Text Available A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI. The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ∼4.5 MeV, the electrons effectively reach the central part of the fuel. To evaluate more realistically the performance of FSI approach, we have used a quasi-two temperature electron energy distribution function of Strozzi (2012 and fast ignitor energy formula of Bellei (2013 that are consistent with 3D PIC simulations for different values of fast ignitor laser wavelength and coupling efficiency. The general advantages of fast-shock ignition in comparison with the shock ignition can be estimated to be better than 1.3 and it is seen that the best results can be obtained for the fuel mass around 1.5 mg, fast ignitor laser wavelength ∼0.3  micron and the shock ignitor energy weight factor about 0.25.

  5. Low power arcjet thruster pulse ignition

    Science.gov (United States)

    Sarmiento, Charles J.; Gruber, Robert P.

    1987-01-01

    An investigation of the pulse ignition characteristics of a 1 kW class arcjet using an inductive energy storage pulse generator with a pulse width modulated power converter identified several thruster and pulse generator parameters that influence breakdown voltage including pulse generator rate of voltage rise. This work was conducted with an arcjet tested on hydrogen-nitrogen gas mixtures to simulate fully decomposed hydrazine. Over all ranges of thruster and pulser parameters investigated, the mean breakdown voltages varied from 1.4 to 2.7 kV. Ignition tests at elevated thruster temperatures under certain conditions revealed occasional breakdowns to thruster voltages higher than the power converter output voltage. These post breakdown discharges sometimes failed to transition to the lower voltage arc discharge mode and the thruster would not ignite. Under the same conditions, a transition to the arc mode would occur for a subsequent pulse and the thruster would ignite. An automated 11 600 cycle starting and transition to steady state test demonstrated ignition on the first pulse and required application of a second pulse only two times to initiate breakdown.

  6. Development of a High Power Programmable Precise Time-Delay Trigger/Ignition System for MFCG

    Institute of Scientific and Technical Information of China (English)

    WU Bi; HE Yuan-hang; ZHANG Qing-ming; MA Yue-fen

    2008-01-01

    High-power precise delay trigger/ignition system is a programmable pulse generator developed for experiment controlling in explosively driven magnetic flux compression generators.Precise delay pulses are generated by the digital circuit,after being magnified and sharpened through multistage isolated amplifiers and rising edge sharpening device,high-voltage steep delay pulses with precision less than us level are obtained.This system has been used in our compact magnetic flux compression generator experiments in place of the traditional primaeord delay device.

  7. Compact Dynamical Foliations

    CERN Document Server

    Carrasco, Pablo D

    2011-01-01

    According to the work of Dennis Sullivan, there exists a smooth flow on the 5-sphere all of whose orbits are periodic although there is no uniform bound on their periods. The question addressed in this article is whether such an example can occur in the partially hyperbolic context. That is, does there exist a partially hyperbolic diffeomorphism of a compact manifold such that all the leaves of its center foliation are compact although there is no uniform bound for their volumes. We will show that the previous question has negative answer under very natural hypothesis as one-dimensional center foliation, transitivity or in the volume preserving case. Moreover we study the dynamical properties of partially hyperbolic maps preserving a compact center foliation. We prove in particular that if the number of center leaves with non-trivial holonomy is finite then the map is plaque expansive.

  8. Hydrogen management strategies using the igniters and recombiners

    International Nuclear Information System (INIS)

    Hydrogen, which is generated by cladding oxidation, can diffuse to all subcompartments in the containment so that high hydrogen concentration may be induced only locally. If the hydrogen concentration in containment reaches to the flammability limit and enough hydrogen is allowed to build up, the hydrogen can ignite and cause a spike in containment pressure that exceeds the containment ultimate design pressure, thereby failing the containment. It is thus important to analyze the accident sequence inducing high hydrogen concentration locally and to develop adequate control and management strategies. In this paper, a framework for evaluating hydrogen control and management strategies involving multiple decisions is presented. The compact influence diagrams including multiple decisions are constructed and evaluated with the MAAP4 calculations. Each decision variable, represented by a node in the influence diagrams, has an uncertainty distribution. Using the values from standard safety analysis report of the reference plant, Advanced Power Reactor 1400MWe (APR1400), the hydrogen control and accident management strategies are assessed. The strategies are ranked with respect to a new measure in terms of hydrogen concentration. The MAAP4 code calculations are performed to generate data for hydrogen concentrations and to identify the important severe accident phenomena in containment for the decision-making analysis as well. In this paper, a problem with two decisions is modeled for a simplistic illustration. One decision is whether or not to actuate the igniters at the time of core uncovery; another decision is to use the passive autocatalytic recombiners (PARs). We chose a small-break loss-of-coolant accident (LOCA) sequence, which was one of the dominant accident sequences in the reference plant, as the reference case. The framework ling of the decision problem by using the decision-making tools, data analysis, and the MAAP4 calculations. It is shown that the proposed

  9. Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C.K.

    2000-07-07

    Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another.

  10. 75 FR 61820 - Model Specifications for Breath Alcohol Ignition Interlock Devices (BAIIDs)

    Science.gov (United States)

    2010-10-06

    ... Specifications for Breath Alcohol Ignition Interlock Devices (BAIIDs). (57 FR 11772.) Ignition interlocks are... National Highway Traffic Safety Administration Model Specifications for Breath Alcohol Ignition Interlock... Breath Alcohol Ignition Interlock Devices (BAIIDs). The Model Specifications are guidelines for...

  11. Differential Diagnosis of Patients with Inconclusive Parkinsonian Features Using [{sup 18}F]FP-CIT PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eunkyung; Hwang, Yu Mi; Lee, Channyoung; Oh, Sun Young; Kim, Young Chul; Choe, Jae Gol; Park, Kun Woo [Korea Univ., Seoul (Korea, Republic of); Kim, Sujin [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2014-06-15

    It is often difficult to differentiate parkinsonism, especially when patients show uncertain parkinsonian features. We investigated the usefulness of dopamine transporter (DAT) imaging for the differential diagnosis of inconclusive parkinsonism using [{sup 18}F]FP-CIT PET. Twenty-four patients with inconclusive parkinsonian features at initial clinical evaluation and nine healthy controls were studied. Patients consisted of three subgroups: nine patients whose diagnoses were unclear concerning whether they had idiopathic Parkinson's disease or drug-induced parkinsonism ('PD/DIP'), nine patients who fulfilled neither the diagnostic criteria of PD nor of essential tremor ('PD/ET'), and six patients who were alleged to have either PD or atypical parkinsonian syndrome ('PD/APS'). Brain PET images were obtained 120 min after injection of 185 MBq [{sup 18}F]FP-CIT. Imaging results were quantified and compared with follow-up clinical diagnoses. Overall, 11 of 24 patients demonstrated abnormally decreased DAT availability on the PET scans, whereas 13 were normal. PET results could diagnose PD/DIP and PD/ET patients as having PD in six patients, DIP in seven, and ET in five; however, the diagnoses of all six PD/APS patients remained inconclusive. Among 15 patients who obtained a final follow-up diagnosis, the image-based diagnosis was congruent with the follow-up diagnosis in 11 patients. Four unsolved cases had normal DAT availability, but clinically progressed to PD during the follow-up period. [{sup 18}F]FP-CIT PET imaging is useful in the differential diagnosis of patients with inconclusive parkinsonian features, except in patients who show atypical features or who eventually progress to PD.

  12. Differential Diagnosis of Patients with Inconclusive Parkinsonian Features Using [18F]FP-CIT PET/CT

    International Nuclear Information System (INIS)

    It is often difficult to differentiate parkinsonism, especially when patients show uncertain parkinsonian features. We investigated the usefulness of dopamine transporter (DAT) imaging for the differential diagnosis of inconclusive parkinsonism using [18F]FP-CIT PET. Twenty-four patients with inconclusive parkinsonian features at initial clinical evaluation and nine healthy controls were studied. Patients consisted of three subgroups: nine patients whose diagnoses were unclear concerning whether they had idiopathic Parkinson's disease or drug-induced parkinsonism ('PD/DIP'), nine patients who fulfilled neither the diagnostic criteria of PD nor of essential tremor ('PD/ET'), and six patients who were alleged to have either PD or atypical parkinsonian syndrome ('PD/APS'). Brain PET images were obtained 120 min after injection of 185 MBq [18F]FP-CIT. Imaging results were quantified and compared with follow-up clinical diagnoses. Overall, 11 of 24 patients demonstrated abnormally decreased DAT availability on the PET scans, whereas 13 were normal. PET results could diagnose PD/DIP and PD/ET patients as having PD in six patients, DIP in seven, and ET in five; however, the diagnoses of all six PD/APS patients remained inconclusive. Among 15 patients who obtained a final follow-up diagnosis, the image-based diagnosis was congruent with the follow-up diagnosis in 11 patients. Four unsolved cases had normal DAT availability, but clinically progressed to PD during the follow-up period. [18F]FP-CIT PET imaging is useful in the differential diagnosis of patients with inconclusive parkinsonian features, except in patients who show atypical features or who eventually progress to PD

  13. The cost effectiveness of 123I-FP-CIT SPECT imaging in patients with an uncertain clinical diagnosis of parkinsonism

    International Nuclear Information System (INIS)

    123I-N-ω-fluoropropyl-2-β-carboxymethoxy-3β-(4-iodophenyl )nortropane (123I-FP-CIT) Single-photon emission computed tomography (SPECT) has been suggested to be a useful diagnostic adjunct in patients with clinically uncertain parkinsonism. We developed a pharmaco-economic (PE) model, evaluating the cost effectiveness of adding 123I-FP-CIT SPECT to the diagnostic workup. As the model was developed before application of the diagnostic technique in real practice, a predictive validity assessment was performed based on data from a large nationwide patient registry in these patients. A PE model, using a Markov state transition model, was created, based on literature-derived and clinical expert panel data. Effects were expressed as adequately treated years (ATY). Key input data were compared to the real-life patterns in a nationwide multi-centre clinical setting, based on a complete national registry of 1,701 consecutive patients. The change in initial diagnosis and alteration of management of the patient after SPECT were registered. In the PE model, it was calculated that management would change in 48.5% of patients by SPECT and that, over a 5-year period, 1.2 ATYs could be gained at a yearly additional cost of EUR72. From the studied 1,701 patients, nigrostriatal degeneration was observed in 59.8%, the initial diagnosis was changed in 51.5%, management was altered in 49%, and cost effectiveness was increased to EUR358 per ATY. Good correspondence between assumed and observed changes in patient management was found, indicating that 123I-FP-CIT SPECT is influential in diagnosis and management of patients with uncertain clinical diagnosis of parkinsonism. This can be achieved at a marginal added cost to the health insurance and leads to a significant gain in ATY. (orig.)

  14. The National Ignition Facility and industry

    International Nuclear Information System (INIS)

    The mission of the National Ignition Facility is to achieve ignition and gain in inertial confinement fusion targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. The National Ignition Facility construction project will require the best of national construction industries and its success will depend on the best products offered by hundreds of the nation's high technology companies. Three-fourths of the construction costs will be invested in industry. This article reviews the design, cost and schedule, and required industrial involvement associated with the construction project

  15. Laser driver beam combination for fast ignition

    International Nuclear Information System (INIS)

    Based on the estimated parameters of fast ignition,the requirements for laser-beam power intensity and energy are used to analyze the possibility of realizing fast ignition by coherent combination and non-coherent combination. The practical distorted wavefront is considered to analyze the far-field focal spot. Non-coherent combination needs more beams for energy requirement and to limit angle drifting in ±2 μrad through improving laser driver's stability. Coherent combination is beneficial for achieving smaller focal spot and higher power intensity, simultaneously reducing the requirement of energy, but single beam wavefront correction can not improve the power intensity in this method, which leads to combined wavefront correction of the total clear aperture with complex monitoring and control methods. Based on the requirement of parameters and wavefront correction capability, non-coherent beam combination is easier to achieve for fast ignition, however, coherent beam combination has the potential for extensive application. (authors)

  16. Ignition threshold for non-Maxwellian plasmas

    CERN Document Server

    Hay, Michael J

    2015-01-01

    An optically thin $p$-$^{11}$B plasma loses more energy to bremsstrahlung than it gains from fusion reactions, unless the ion temperature can be elevated above the electron temperature. In thermal plasmas, the temperature differences required are possible in small Coulomb logarithm regimes, characterized by high density and low temperature. The minimum Lawson criterion for thermal $p$-$^{11}$B plasmas and the minimum $\\rho R$ required for ICF volume ignition are calculated. Ignition could be reached more easily if the fusion reactivity can be improved with nonthermal ion distributions. To establish an upper bound for this utility, we consider a monoenergetic beam with particle energy selected to maximize the beam- thermal reactivity. Channeling fusion alpha energy to maintain such a beam facilitates ignition at lower densities and $\\rho R$, improves reactivity at constant pressure, and could be used to remove helium ash. The gains realized with a beam thus establish an upper bound for the reductions in igniti...

  17. Progress on LMJ targets for ignition

    Energy Technology Data Exchange (ETDEWEB)

    Cherfils-Clerouin, C; Boniface, C; Bonnefille, M; Fremerye, P; Galmiche, D; Gauthier, P; Giorla, J; Lambert, F; Laffite, S; Liberatore, S; Loiseau, P; Malinie, G; Masse, L; Masson-Laborde, P E; Monteil, M C; Poggi, F; Seytor, P; Wagon, F; Willien, J L, E-mail: catherine.cherfils@cea.f [CEA, DAM, DIF, F-91297 Arpajon (France)

    2010-08-01

    Targets designed to produce ignition on the Laser MegaJoule are presented. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4MJ and 380TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-shaped cocktail hohlraum. 1D and 2D robustness evaluations of these different targets shed light on critical points for ignition, that can be traded off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

  18. Progress on LMJ targets for ignition

    Energy Technology Data Exchange (ETDEWEB)

    Cherfils-Clerouin, C; Boniface, C; Bonnefille, M; Dattolo, E; Galmiche, D; Gauthier, P; Giorla, J; Laffite, S; Liberatore, S; Loiseau, P; Malinie, G; Masse, L; Masson-Laborde, P E; Monteil, M C; Poggi, F; Seytor, P; Wagon, F; Willien, J L, E-mail: catherine.cherfils@cea.f [CEA, DAM, DIF, F-91297 Arpajon (France)

    2009-12-15

    Targets designed to produce ignition on the Laser Megajoule (LMJ) are being simulated in order to set specifications for target fabrication. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4 MJ and 380 TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-ball shaped cocktail hohlraum; with these improvements, a target based on the 240-beam A1040 capsule can be included in the 160-beam laser energy-power space. Robustness evaluations of these different targets shed light on critical points for ignition, which can trade off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

  19. Ignition Failure Mode Radiochemical Diagnostics Initial Assessment

    International Nuclear Information System (INIS)

    Radiochemical diagnostic signatures are well known to be effective indicators of nuclear ignition and burn reaction conditions. Nuclear activation is already a reliable technique to measure yield. More comprehensively, though, important quantities such as fuel areal density and ion temperature might be separately and more precisely monitored by a judicious choice of select nuclear reactions. This report details an initial assessment of this approach to diagnosing ignition failures on point-design cryogenic National Ignition Campaign targets. Using newly generated nuclear reaction cross section data for Scandium and Iridium, modest uniform doping of the innermost ablator region provides clearly observable reaction product differences between robust burn and failure for either element. Both equatorial and polar tracer loading yield observable, but indistinguishable, signatures for either choice of element for the preliminary cases studied

  20. Ignition of THKP and TKP pyrotechnic powders :

    Energy Technology Data Exchange (ETDEWEB)

    Maharrey, Sean P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Erikson, William W [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Highley, Aaron M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wiese-Smith, Deneille [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kay, Jeffrey J [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-03-01

    We have conducted Simultaneous Thermogravimetric Modulated Beam Mass Spectrometry (STMBMS) experiments on igniter/actuator pyrotechnic powders to characterize the reactive processes controlling the ignition and combustion behavior of these materials. The experiments showed a complex, interactive reaction manifold involving over ten reaction pathways. A reduced dimensionality reaction manifold was developed from the detailed 10-step manifold and is being incorporated into existing predictive modeling codes to simulate the performance of pyrotechnic powders for NW component development. The results from development of the detailed reaction manifold and reduced manifold are presented. The reduced reaction manifold has been successfully used by SNL/NM modelers to predict thermal ignition events in small-scale testing, validating our approach and improving the capability of predictive models.

  1. Target Visualization at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Potter, Daniel Abraham [Univ. of California, Davis, CA (United States)

    2011-01-01

    As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the targets used to achieve this goal. Techniques have been developed to measure target surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. Using these techniques we are able to produce a detailed view of the shell surface, which in turn allows us to refine target manufacturing and cleaning processes. However, the volume of data produced limits the methods by which this data can be effectively viewed by a user. This paper introduces an image-based visualization system for data exploration of target shells at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. It aims to combine multiple image sets into a single visualization to provide a method of navigating the data in ways that are not possible with existing tools.

  2. Contenido de ADN y nivel de ploidía en Tagetes spp. Utilizando citómetro de flujo

    OpenAIRE

    Miguel Ángel Serrato Cruz; Martha Hernández Rodríguez; Yves Savidan; Nina M. Bárcenas Ortega

    2000-01-01

    Se determinó la asociación entre el contenido de ADN nuclear y el nivel de ploidía de siete poblaciones de Tagetes spp. El contenido de ADN se estimó mediante citómetro de flujo utilizando a Zea mays L. como estándar interno. El recuento de cromosomas se hizo en preparaciones citológicas teñidas con acetocarmín. T. erecta, T. foetidissima, T. tenuifolia (dos ecotipos) y dos poblaciones silvestres no identificadas mostraron un contenido promedio de ADN de 2.61±0.23 pg correspondiendo a la ploi...

  3. Pratiques et politiques sportives dans les quartiers sensibles : une approche monographique aux 3Cités à Poitiers

    OpenAIRE

    Moussa, Kinda

    2013-01-01

    Our study is a one of the possible keys to understanding the various present-day types of sports activities and recreational and cultural sports practiced by the people living in the 3Cités, a working class neighborhood in Poitiers (France). We inquire about the role of the neighborhood as a defining element of identification which reshapes the pratice of sports activities and redevelops public space. Not only sports activities, but also social and cultural activities seem thus to depend both...

  4. Differentiation of dementia with lewy bodies from Alzheimer's disease using FDG PET and I-123-fluoropropyl-β-CIT SPECT

    International Nuclear Information System (INIS)

    Dementia with Lewy bodies (DLB) shares clinical and pathological features with Alzheimer's disease (AD) and Parkinson's disease. The differentiation of DLB from these disorders poses difficulties. We compared regional cerebral metabolic impairment and dopaminergic neuronal integrity between patients with DLB and AD using FDG PET and I-123-fluoropropyl-β-CIT (FP-CIT) SPECT, respectively, as measures for differential diagnosis. Fourteen clinically diagnosed DLB patients, 15 probable AD patients, and 12 age- and gender-matched healthy controls were studied with FDG PET and FP-CIT SPECT. A voxel-wise comparison of PET images was performed using SPM99. A dopamine transporter (DAT) parameter V3 was calculated in striatal regions as (striatal VOIcerebellar VOI)/cerebellar VOI activity on SPECT images obtained 3 h after injection of 185 MBq FP-CIT. SPM analysis of PET images of DLB revealed hypometabolism bilaterally in the occipital cortices, lateral occipitotemporal gyri, cunei, caudate, and Thalami compared with controls, most pronounced in the occipital cortex compared with AD. In DLB, V3 in the caudate (1.07±0.55) and putamen (1.01±0.34) was significantly (P < 0.001) lower than in AD (2.73±0.75 and 3.17±0.88, respectively) and controls (3.00±0.45 and 3.11±0.31, respectively). There was no significant difference in striatal V3 between AD and controls. The ratio of putamen-to-caudate V3 was not significantly different between DLB (1.04±0.32) and controls (1.05±0.12), indicating that DATs in the caudate and putamen are evenly affected in DLB. In DLB, there was a significant correlation between striatal V3 and MMSE score (rho=0.97, P<0.01). These data demonstrate different biochemical features between DLB and AD, in terms of regional brain metabolism and dopaminergic neuronal integrity. Measures of the glucose metabolism in the occipital cortex and the striatal DAT density may be informative diagnostic aids to distinguish DLB from AD

  5. [123I]FP-CIT (DaTSCAN) and SPET in the diagnostics of Parkinson's disease and Parkinsonian syndromes

    International Nuclear Information System (INIS)

    The aim of study was to verify the diagnostic value of the radiopharmaceutic [123I]FP-CIT (DaTSCAN) in functional imaging of the presynaptical dopaminergic system in patients with Parkison's disease and parkinsonian syndromes: multiple system atrophy, orthostatic hypotonia Shy-Drager, essential tremor. That pilot study group consisted of 8 patients in which either preliminary diagnosis or suspicion of Parkinson's disease, parkinsonian syndrome or multiple system atrophy was set. Imaging of the brain with SPET (dual head detector Varicam Elscint) and MRI were performed. The radiopharmaceutic [123I] FP-CIT (DaTSCAN) was administered intravenously in the dose 145 -148 MBq. SPET images were reconstructed by filtered backprojection with the use of Butterworth filter. The images were inspected visually. Images from SPET and MRI were superimposed by means of the workstation Hermes (Nucklear Diagnostic) with designatad regions interest (ROI) in the striatum and occipital cortex in order to assess semiquantitatively the binding of dopamine transporter. In the group of 8 patients evaluated with the use of [123I]FP-CIT DaTSCAN four had normal results, and four - abnormal. The preliminary diagnosis was sustained in 3/8 of patients (including Parkinson's disease in two patients and multiple system atrophy in one patient). In the remainig 5 patients the preliminary diagnosis was changed, namely: in 2 cases the essential tremor was diagnosed, in 1 case - Parkinson's disease, in 1 case - orthostaic Sky-Drager, and in 1 case - despite the tremor of the upper limbs - results were normal. In all 8 patients the tracer proved to be useful in the confirmation of clinical diagnosis, especially in the differentiation between the essential tremor and Parkinson's disease. In the case of multiple system atrophy the imaging revealed significant loss of nigrostriatal dopaminergic neurons. Such loss was observed also in the cases of Parkinson's disease affecting the posterior parts of the

  6. cit de voyage et tourisme de mémoire : The Island Martinique de John Wideman

    OpenAIRE

    Duboin, Corinne

    2015-01-01

    L’écrivain africain-américain John Edgar Wideman publie en 2003 un récit de voyage commandité par la National Geographic Society. L’écrivain choisit pour destination la Martinique. Etranger dans cette île de la Caraïbe francophone, mais lui-même héritier d’une Histoire coloniale transatlantique douloureuse, il retranscrit son expérience sensible d’un espace insulaire revisité, guidant ses lecteurs dans un périple touristique et scriptural qui se transforme en un questionnement sur soi et son ...

  7. National Ignition Facility Target Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-10-05

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This

  8. National Ignition Facility Target Chamber

    International Nuclear Information System (INIS)

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

  9. National Ignition Facility project acquisition plan revision 1

    International Nuclear Information System (INIS)

    The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility M Project. It was prepared for the NIP Prood Office by the NIF Procurement Manager

  10. Highly Durable Catalysts for Ignition of Advanced Monopropellants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Monopropellants are readily ignited or decomposed over a bed of solid catalyst. A serious limitation of existing catalysts in the ignition of advanced...

  11. On the ignition of the ITER machine

    International Nuclear Information System (INIS)

    The present study on a simple model of the ITER machine (International Thermonuclear Experimental Reactor) shows that this machine, as presently designed, might not be able to reach either ignition or power breakeven. The large cost and the long time frame of the ITER program, on the other hand, do not allow for any doubt that the machine must reach its stated goal of ignition. Consequently, as long as these doubts persist, and cannot easily be dissipated, the ITER program should be put on hold, and fusion alternative concepts should be pursued. (author)

  12. Semiconductor bridge, SCB, ignition of energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Bickes, R.W.; Grubelich, M.D.; Harris, S.M.; Merson, J.A.; Tarbell, W.W.

    1997-04-01

    Sandia National Laboratories` semiconductor bridge, SCB, is now being used for the ignition or initiation of a wide variety of exeoergic materials. Applications of this new technology arose because of a need at the system level to provide light weight, small volume and low energy explosive assemblies. Conventional bridgewire devices could not meet the stringent size, weight and energy requirements of our customers. We present an overview of SCB technology and the ignition characteristics for a number of energetic materials including primary and secondary explosives, pyrotechnics, thermites and intermetallics. We provide examples of systems designed to meet the modern requirements that sophisticated systems must satisfy in today`s market environments.

  13. Plasma igniter for internal combustion engine

    Science.gov (United States)

    Fitzgerald, D. J.; Breshears, R. R. (Inventor)

    1978-01-01

    An igniter for the air/fuel mixture used in the cylinders of an internal combustion engine is described. A conventional spark is used to initiate the discharge of a large amount of energy stored in a capacitor. A high current discharge of the energy in the capacitor switched on by a spark discharge produces a plasma and a magnetic field. The resultant combined electromagnetic current and magnetic field force accelerates the plasma deep into the combustion chamber thereby providing an improved ignition of the air/fuel mixture in the chamber.

  14. Fast Ignition Transport Simulations for NIF

    International Nuclear Information System (INIS)

    This paper shows work at Lawrence Livermore National Lab (LLNL) devoted to modeling the propagation of, and heating by, a relativistic electron beam in a idealized dense fuel assembly for fast ignition. The implicit particle-in-cell (PIC) code LSP is used. Experiments planned on the National Ignition Facility (NIF) in the next few years using the Advanced Radiography Capability (ARC) short-pulse laser motivate this work. We demonstrate significant improvement in the heating of dense fuel due to magnetic forces, increased beam collimation, and insertion of a finite-radius carbon region between the beam excitation and fuel regions.

  15. Chaotic combustion in spark ignition engines

    International Nuclear Information System (INIS)

    We analyse the combustion process in a spark ignition engine using the experimental data of an internal pressure during the combustion process and show that the system can be driven to chaotic behaviour. Our conclusion is based on the observation of unperiodicity in the time series, suitable stroboscopic maps and a complex structure of a reconstructed strange attractor. This analysis can explain that in some circumstances the level of noise in spark ignition engines increases considerably due to nonlinear dynamics of a combustion process

  16. Compact fusion reactors

    International Nuclear Information System (INIS)

    Compact, high-power-density approaches to fusion power are proposed to improve economic viability through the use of less-advanced technology in systems of considerably reduced scale. The rationale for and the means by which these systems can be achieved are discussed, as are unique technological problems

  17. Limestone compaction: an enigma

    Science.gov (United States)

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  18. Tachyons in Compact Spaces

    CERN Document Server

    Suyama, T

    2005-01-01

    We discuss condensations of closed string tachyons localized in compact spaces. Time evolution of an on-shell condensation is naturally related to the worldsheet RG flow. Some explicit tachyonic compactifications of Type II string theory is considered, and some of them are shown to decay into supersymmetric theories known as the little string theories.

  19. Scaling laws for ignition at the National Ignition Facility from first principles.

    Science.gov (United States)

    Cheng, Baolian; Kwan, Thomas J T; Wang, Yi-Ming; Batha, Steven H

    2013-10-01

    We have developed an analytical physics model from fundamental physics principles and used the reduced one-dimensional model to derive a thermonuclear ignition criterion and implosion energy scaling laws applicable to inertial confinement fusion capsules. The scaling laws relate the fuel pressure and the minimum implosion energy required for ignition to the peak implosion velocity and the equation of state of the pusher and the hot fuel. When a specific low-entropy adiabat path is used for the cold fuel, our scaling laws recover the ignition threshold factor dependence on the implosion velocity, but when a high-entropy adiabat path is chosen, the model agrees with recent measurements. PMID:24229109

  20. Effect of Oxygen Concentration on Autogenous Ignition Temperature and Pneumatic Impact Ignitability of Nonmetallic Materials

    Science.gov (United States)

    Smith, Sarah

    2009-01-01

    Extensive test data exist on the ignitability of nonmetallic materials in pure oxygen, but these characteristics are not as well understood for lesser oxygen concentrations. In this study, autogenous ignition temperature testing and pneumatic impact testing were used to better understand the effects of oxygen concentration on ignition of nonmetallic materials. Tests were performed using oxygen concentrations of 21, 34, 45, and 100 %. The following materials were tested: PTFE Teflon(Registered Trademark), Buna-N, Silicone, Zytel(Registered Trademark) 42, Viton(registered Trademark) A, and Vespel(Registered Trademark) SP-21.

  1. Igniters for Liquid Oxygen/Liquid Methane Technology Development

    Science.gov (United States)

    Osborne, Robin J.; Elam, Sandra K.; Peschel, William P.

    2008-01-01

    As part of NASA's technology development of liquid methane / liquid oxygen engines for future exploration missions, two different igniters were recently studied at NASA Marshall Space Flight Center. The first igniter tested was an impinging injection, spark-initiated torch igniter, and the second was a microwave-generated plasma igniter. The purpose of the ignition tests was to define the ignition limits under vacuum conditions and characterize the transient start-up performance as a function of propellant mixture ratio (MR), mass flow rates, inlet temperatures, and pre-ignition chamber pressure. In addition, for the impinging igniter two different spark plugs were tested, and for the microwave igniter the magnetron filament warm-up time and the magnetron input power were both varied. The results gathered from these tests indicated that the impinging igniter is capable of operating over an MR range of 2 - 27, with methane and oxygen inlet temperatures as low as -161 F and -233 F, respectively. The microwave igniter was tested over an MR range of 2 - 9, with methane and oxygen inlet temperatures as low as -90 F and -200 F, respectively. The microwave igniter achieved ignition over this range, although an upper ignition limit was determined for the oxidizer mass flow rate. In general, the torch exhaust temperatures for the microwave igniter were not as high as those attained with the impinging igniter. The microwave igniter, however, was hot-fired 17 times and was still operational, whereas the impinging igniter spark plugs experienced thermal shock and erosion over nine hot-fire tests. It was concluded that for the microwave igniter better mixing of the propellants might be required in order to both raise the torch exhaust temperature and decrease the required magnetron input power, and for the impinging igniter the spark plug position within the igniter chamber should be varied in future tests to identify a more optimal location. All of the igniter tests were

  2. Imaging the pre- and postsynaptic side of striatal dopaminergic synapses in idiopathic cervical dystonia: a SPECT study using [123I] epidepride and [123I] beta-CIT.

    Science.gov (United States)

    Naumann, M; Pirker, W; Reiners, K; Lange, K W; Becker, G; Brücke, T

    1998-03-01

    There is increasing evidence that a dysfunction of the dopaminergic system may be involved in the pathogenesis of idiopathic dystonia. To visualize possible alterations of the pre- and postsynaptic side of striatal dopaminergic synapses, SPECT studies using the radiotracers [123I] epidepride and [123I] beta-CIT were performed in 10 patients with idiopathic cervical dystonia. Eleven age- and sex-matched subjects served as controls. [123I] Epidepride is a new highly affine marker of D2 receptors, and [123I] beta-CIT binds to dopamine transporters on dopaminergic nerve endings. [123I] Epidepride binding was significantly reduced in both striata of dystonia patients compared with controls (p < 0.05). In contrast, striatal [123I beta-CIT uptake did not differ from controls. We conclude that dopaminergic dysfunction in idiopathic focal dystonia mainly involves postsynaptic mechanisms and suggest a disturbance of the indirect pathway of the motor circuit resulting in a disinhibited thalamocortical stimulation. PMID:9539347

  3. Effects of cocaine on [11C]norepinephrine and [11C]β-CIT uptake in the primate peripheral organs measured by PET

    International Nuclear Information System (INIS)

    The toxic properties of cocaine are related to both the central and peripheral effects. To identify possible lethal mechanisms and the accumulation of cocaine in various organs, the effects of cocaine on [11C] norepinephrine and cocaine congener [11C]β-CIT uptake in Cynomolgus monkeys were measured by positron emission tomography (PET). Cocaine (5 mg/kg) noticeably inhibited [11C] norepinephrine uptake in the heart. The uptake of [11C]β-CIT in the heart and lung was reduced by pretreatment with cocaine. There was a significant uptake in the liver which was increased following cocaine pretreatment. The results of this study confirm that cocaine blocks the neuronal uptake of norepinephrine in sympathetic nerve terminals in the myocardium. The effect of cocaine on [11C]β-CIT uptake indicates that the binding sites in the heart and lung are saturable, while the uptake mechanism in the liver is different from those of the heart and lung. (author)

  4. Cité et territoire celtique à travers l'exemple du Belgium

    Directory of Open Access Journals (Sweden)

    Fichtl, Stephan

    2003-12-01

    Full Text Available [es] El origen de las ciudades de Belgium (Bellovaci, Ambiarli y Atrebates se puede situar a fines del s. iv o comienzos del s. Ill a.C. Se vincula a la llegada de una nueva población que se instala en el Noroeste de la Galia, resultado de una migración negociada. Rápidamente, el territorio se estructura con la fundación de una primera serie de grandes santuarios: Gournay-sur-Aronde, Rubemont-sur-Ancre, Moeuvres. Esta organización del territorio necesitó para realizarse muchas décadas y no es hasta comienzos del s. II cuando comenzó a estabilizarse. La organización se apoya siempre en dichos santuarios cuyo papel seguirá siendo preponderante hasta la época de La Tène final, cuando los oppida no harán nada más que superponerse a estos sitios. [fr] L'origine des cités du Belgium (Bellovaques, Ambiens et Atrébates peut être placée à la fin du IVe s. ou au début du Ille s. av. J.-C. Elle est liée à l'arrivée d'une nouvelle population qui s'installe dans le nord-ouest de la Gaule suite à une migration négociée. Très rapidement le territoire se structure autour de la fondation d'une première série de grands sanctuaires: Gournay-sur-Aronde, Ribemont-sur-Ancre, Moeuvres. Cette organisation du territoire a nécessité plusieurs décennies et ce n'est qu'au début du IIe s. que le territoire commence à se stabiliser. L'organisation s'appuie toujours sur les sanctuaires dont le rôle restera encore prépondérant à La Tène finale, les oppida ne venant que se superposer à ces sites.

  5. 14 CFR 25.981 - Fuel tank ignition prevention.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank ignition prevention. 25.981 Section 25.981 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... ignition prevention. (a) No ignition source may be present at each point in the fuel tank or fuel...

  6. Machine learning models for the differential diagnosis of vascular parkinsonism and Parkinson's disease using [{sup 123}I]FP-CIT SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Huertas-Fernandez, I.; Benitez-Rivero, S.; Jesus, S.; Caceres-Redondo, M.T.; Martin-Rodriguez, J.F.; Carrillo, F. [Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurologia y Neurofisiologia Clinica, Seville (Spain); Garcia-Gomez, F.J.; Marin-Oyaga, V.A.; Lojo, J.A. [Hospital Universitario Virgen del Rocio, Servicio de Medicina Nuclear, UDIM, Seville (Spain); Garcia-Solis, D. [Hospital Universitario Virgen del Rocio, Servicio de Medicina Nuclear, UDIM, Seville (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Seville (Spain); Mir, P. [Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurologia y Neurofisiologia Clinica, Seville (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Seville (Spain)

    2015-01-15

    The study's objective was to develop diagnostic predictive models using data from two commonly used [{sup 123}I]FP-CIT SPECT assessment methods: region-of-interest (ROI) analysis and whole-brain voxel-based analysis. We included retrospectively 80 patients with vascular parkinsonism (VP) and 164 patients with Parkinson's disease (PD) who underwent [{sup 123}I]FP-CIT SPECT. Nuclear-medicine specialists evaluated the scans and calculated bilateral caudate and putamen [{sup 123}I]FP-CIT uptake and asymmetry indices using BRASS software. Statistical parametric mapping (SPM) was used to compare the radioligand uptake between the two diseases at the voxel level. Quantitative data from these two methods, together with potential confounding factors for dopamine transporter availability (sex, age, disease duration and severity), were used to build predictive models following a tenfold cross-validation scheme. The performance of logistic regression (LR), linear discriminant analysis and support vector machine (SVM) algorithms for ROI data, and their penalized versions for SPM data (penalized LR, penalized discriminant analysis and SVM), were assessed. Significant differences were found in the ROI analysis after covariate correction between VP and PD patients in [{sup 123}I]FP-CIT uptake in the more affected side of the putamen and the ipsilateral caudate. Age, disease duration and severity were also found to be informative in feeding the statistical model. SPM localized significant reductions in [{sup 123}I]FP-CIT uptake in PD with respect to VP in two specular clusters comprising areas corresponding to the left and right striatum. The diagnostic predictive accuracy of the LR model using ROI data was 90.3 % and of the SVM model using SPM data was 90.4 %. The predictive models built with ROI data and SPM data from [{sup 123}I]FP-CIT SPECT provide great discrimination accuracy between VP and PD. External validation of these methods is necessary to confirm their

  7. [{sup 123}]FP-CIT SPECT scans initially rated as normal became abnormal over time in patients with probable dementia with Lewy bodies

    Energy Technology Data Exchange (ETDEWEB)

    Zande, J.J. van der; Scheltens, P.; Lemstra, A.W. [VU Medical Center Alzheimer Center, Amsterdam (Netherlands); Booij, J. [Academic Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Raijmakers, P.G.H.M. [VU Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands)

    2016-06-15

    Decreased striatal dopamine transporter (DAT) binding on SPECT imaging is a strong biomarker for the diagnosis of dementia with Lewy bodies (DLB). There is still a lot of uncertainty about patients meeting the clinical criteria for probable DLB who have a normal DAT SPECT scan (DLB/S-). The aim of this study was to describe the clinical and imaging follow-up in these patients, and compare them to DLB patients with abnormal baseline scans (DLB/S+). DLB patients who underwent DAT imaging ([{sup 123}I]FP-CIT SPECT) were selected from the Amsterdam Dementia Cohort. All [{sup 123}I]FP-CIT SPECT scans were evaluated independently by two nuclear medicine physicians and in patients with normal scans follow-up imaging was obtained. We matched DLB/S- patients for age and disease duration to DLB/S+ patients and compared their clinical characteristics. Of 67 [{sup 123}I]FP-CIT SPECT scans, 7 (10.4 %) were rated as normal. In five DLB/S- patients, a second [{sup 123}I]FP-CIT SPECT was performed (after on average 1.5 years) and these scans were all abnormal. No significant differences in clinical characteristics were found at baseline. DLB/S- patients could be expected to have a better MMSE score after 1 year. This study was the first to investigate DLB patients with the initial [{sup 123}I]FP-CIT SPECT scan rated as normal and subsequent scans during disease progression rated as abnormal. We hypothesize that DLB/S- scans could represent a relatively rare DLB subtype with possibly a different severity or spread of alpha-synuclein pathology (''neocortical predominant subtype''). In clinical practice, if an alternative diagnosis is not imminent in a DLB/S- patient, repeating [{sup 123}I]FP-CIT SPECT should be considered. (orig.)

  8. A new model for separation between brain dopamine and serotonin transporters in {sup 123}I-{beta}-CIT SPECT measurements: normal values and sex and age dependence

    Energy Technology Data Exchange (ETDEWEB)

    Ryding, Erik; Rosen, Ingmar [Department of Clinical Neurophysiology, University Hospital, Lund (Sweden); Lindstroem, Mats; Bosson, Peter; Traeskman-Bendz, Lil [Department of Psychiatry, University Hospital, Lund (Sweden); Braadvik, Bjoern; Grabowski, Martin [Department of Neurology, University Hospital, Lund (Sweden)

    2004-08-01

    {sup 123}I-{beta}-CIT is a radioactive ligand for single-photon emission computed tomography (SPECT) imaging of the pre-synaptic (transporter) re-uptake sites for dopamine (DAT) and serotonin (5HTT), and it is widely used to visualize monoamine turnover. Since {sup 123}I-{beta}-CIT uptake occurs at 5HTT and DAT sites in conjunction with the presence of freely soluble {sup 123}I-{beta}-CIT in brain tissue, adequate separation of these three components is necessary. However, only partial separation is possible with current methods. Two main strategies have previously been used for {sup 123}I-{beta}-CIT component separation, based on the following considerations: (1) the faster uptake rate for 5HTT compared with DAT enables temporal separation by performing 5HTT imaging at 1-2 h and DAT imaging at 20-24 h; (2) blocking the 5HTT re-uptake with citalopram renders {sup 123}I-{beta}-CIT imaging DAT (non-5HTT) specific. In a new analytical model, we combined these two approaches with methods to isolate the passively dissolved {sup 123}I-{beta}-CIT in brain tissue from the monoamine transporter uptake, and to correct the 5HTT and DAT values for concomitant uptake. The new analytical model was used to study brain 5HTT and DAT in 23 normal subjects, with the aim of clarifying the effect of age and sex. A significant correlation between 5HTT and DAT values was found only in the thalamus, indicating successful component separation. Negative correlations between age and DAT were found for basal ganglia, thalami, brain stem and temporal lobes, but not for the frontal, parietal or occipital regions. No correlation with age was found for 5HTT. We found no sex difference for 5HTT or DAT. (orig.)

  9. Analysis of cyclic variations during mode switching between spark ignition and controlled auto-ignition combustion operations

    OpenAIRE

    Chen, T.; Zhao, H; Xie, H.; He, B.

    2014-01-01

    © IMechE 2014. Controlled auto-ignition, also known as homogeneous charge compression ignition, has been the subject of extensive research because of their ability to provide simultaneous reductions in fuel consumption and NOx emissions from a gasoline engine. However, due to its limited operation range, switching between controlled auto-ignition and spark ignition combustion is needed to cover the complete operating range of a gasoline engine for passenger car applications. Previous research...

  10. Autoradiographic study of dopamine transporter in rat Model of Parkinson' s disease with 125I-β-CIT

    Institute of Scientific and Technical Information of China (English)

    Liu Zhenguo; Chen Shengdi; Shum Wenshan

    2000-01-01

    Objective To evaluate the value of iaaging for dopamine transpter(DAT) wi th 125I- β-CIT. Methods The partial and complete lesioned rat models of hemiparkinsonism were rendered with 6- hydroxy-dopamine (6-OHDA). Each rat was injected intravenously with 1251-β-CIT containing 40 μ Ci. Coronal t issue sections were imaged by autoradiography. The levets of dopamine (DA)and its metabolites were measured by high performance 1iquid choromatography and electro-chemical detection (HPLC-ECD). The t yros i nc hydroxylase(Tll)-positive cells and fibres in substantia nigra and striatum of the rats were observed by immunohistochemieal staining. Results The radioactivities in the lesioned striatum of both partial and complete lesioned hemiparkinsonian rats were 2.67±0.25 and O. 98±0.29 respectively , and were singificantly decreased by.18% and 72% respectively, as compared with those of unlesioned side. The levels of DA in the lesioned striatum of partial and complete lesioned models were decreased by 39% and 98% respectively. The loss of TH-positive eells and fibres in the substantia nigra and striatum was found in the lesioned striatum of both partial and complete-lesioned models. Conclusion The imaging study of DAT may be helpful for the early diagnosis of Parkinson's disease and for the monitor of the progression of this discaose;.

  11. Impacts assessment for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bay Area Economics

    1996-12-01

    This report documents the economic and other impacts that will be created by the National Ignition Facility (NIF) construction and ongoing operation, as well as the impacts that may be created by new technologies that may be developed as a result of NIF development and operation.

  12. Deep Dive Topic: Approach to ignition

    Energy Technology Data Exchange (ETDEWEB)

    Hurricane, O. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kline, J. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Meezan, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mackinnon, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-14

    The current high-foot and related implosions have adequate CR and implosion velocity to ignite, but require improved finesse particularly in, but not limited to, implosion symmetry. This is being pursued. The challenge of controlling drive symmetry is also motivating lower convergence ratio designs. These require higher velocity implosions and are also being pursued.

  13. Target requirements on the path to ignition

    International Nuclear Information System (INIS)

    The Los Alamos ICF program has made several advances in learning what is required for ignition on NIF. This work continues to focus on beryllium--understanding why it appears less sensitive to DT ice roughness, the feed-out/feed-in phenomena, applying that understanding to new designs, performing experiments to confirm this mechanism, and studying the effects of joints in beryllium components

  14. Fusion energy from plasma block ignition

    Czech Academy of Sciences Publication Activity Database

    Hora, H.; Badziak, J.; Glowacz, S.; Jablonski, S.; Skladanowski, Z.; Osman, F.; Cang, Y.; Zhang, J.; Miley, G. H.; Peng, H.; He, X.; Zhang, W.; Rohlena, Karel; Ullschmied, Jiří; Jungwirth, Karel

    2005-01-01

    Roč. 23, - (2005), s. 423-432. ISSN 0263-0346 R&D Projects: GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z10100523 Keywords : fusion energy * laser fusion * nonlinear force * plasma block ignition * ponderomotion * skin layer Subject RIV: BH - Optics, Masers, Laser s Impact factor: 2.590, year: 2005

  15. National Ignition Facility frequency converter development

    International Nuclear Information System (INIS)

    A preliminary error budget for the third harmonic converter for the National Ignition Facility (NIF) laser driver has been developed using a root-sum-square-accumulation of error sources. Such a budget sets an upper bound on the allowable magnitude of the various effects that reduce conversion efficiency. Development efforts on crystal mounting technology and crystal quality studies are discussed

  16. Catalytic bi-propellant ignition technology development

    NARCIS (Netherlands)

    Bouquet, F.; Mayer, A.; Snijders, H.; Brauers, B.

    2010-01-01

    For the next generation high thrust engine Aerospace Propulsion Products (APP) and TNO Defence Security and Safety are developing technology for a high-power innovative restartable igniter working on 90% hydrogen peroxide and a liquid or gaseous fuel (ethanol, methane or hydrogen). This development

  17. Toroidal Alfven wave stability in ignited tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, C.Z.; Fu, G.Y.; Van Dam, J.W.

    1989-01-01

    The effects of fusion-product alpha particles on the stability of global-type shear Alfven waves in an ignited tokamak plasma are investigated in toroidal geometry. Finite toroidicity can lead to stabilization of the global Alfven eigenmodes, but it induces a new global shear Alfven eigenmodes, which is strongly destabilized via transit resonance with alpha particles. 8 refs., 2 figs.

  18. Plasma ignition for medium calibre ammunition

    NARCIS (Netherlands)

    Driel, C.A. van; Schilt, A.; Simor, M.; Schaffers, P.; Weise, T.

    2012-01-01

    Gun performance is usually affected by the operating temperature of the ammunition or weapon. This is caused by several factors, amongst which the temperature dependency of the propellant ignition and combustion processes. Compensation of temperature effects on weapon or ammunition performance is po

  19. National Ignition Facility design focuses on optics

    International Nuclear Information System (INIS)

    Sometime in the year 2002, scientists at the National Ignition Facility (NIF) will focus 192 separate high-power ultraviolet laser beams onto a tiny capsule of deuterium and tritium, heating and compressing the material until it ignites and burns with a burst of fusion energy. The mission of NIF, which will contain the largest laser in the world, is to obtain fusion ignition and gain and to use inertial confinement fusion capabilities in nuclear weapons science experiments. The physics data provided by NIF experiments will help scientists ensure nuclear weapons reliability without the need for actual weapons tests; basic sciences such as astrophysics will also benefit. The facility faces stringent weapons-physics user requirements demanding peak pulse powers greater than 750 TW at 0.35 microm (only 500 TW is required for target ignition), pulse durations of 0.1 to 20 ns, beam steering on the order of several degrees, and target isolation from residual 1- and 0.5-microm radiation. Additional requirements include 50% fractional encircled beam energy in a 100-microm-diameter spot, with 95% encircled in a 200-microm spot. The weapons-effects community requires 1- and 0.5-microm light on target, beam steering to widely spaced targets, a target chamber accommodating oversized objects, well-shielded diagnostic areas, and elimination of stray light in the target chamber. The beamline design, amplifier configuration and requirements for optics are discussed here

  20. Application of Alcohols to Dual - Fuel Feeding the Spark-Ignition and Self-Ignition Engines

    OpenAIRE

    Stelmasiak Zdzisław

    2014-01-01

    This paper concerns analysis of possible use of alcohols for the feeding of self - ignition and spark-ignition engines operating in a dual- fuel mode, i.e. simultaneously combusting alcohol and diesel oil or alcohol and petrol. Issues associated with the requirements for application of bio-fuels were presented with taking into account National Index Targets, bio-ethanol production methods and dynamics of its production worldwide and in Poland. Te considerations are illustrated by results of t...

  1. Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility

    International Nuclear Information System (INIS)

    Point design targets have been specified for the initial ignition campaign on the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. The targets contain D-T fusion fuel in an ablator of either CH with Ge doping, or Be with Cu. These shells are imploded in a U or Au hohlraum with a peak radiation temperature set between 270 and 300 eV. Considerations determining the point design include laser-plasma interactions, hydrodynamic instabilities, laser operations, and target fabrication. Simulations were used to evaluate choices, and to define requirements and specifications. Simulation techniques and their experimental validation are summarized. Simulations were used to estimate the sensitivity of target performance to uncertainties and variations in experimental conditions. A formalism is described that evaluates margin for ignition, summarized in a parameter the Ignition Threshold Factor (ITF). Uncertainty and shot-to-shot variability in ITF are evaluated, and sensitivity of the margin to characteristics of the experiment. The formalism is used to estimate probability of ignition. The ignition experiment will be preceded with an experimental campaign that determines features of the design that cannot be defined with simulations alone. The requirements for this campaign are summarized. Requirements are summarized for the laser and target fabrication.

  2. Fundamental Studies of Ignition Process in Large Natural Gas Engines Using Laser Spark Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Azer Yalin; Bryan Willson

    2008-06-30

    Past research has shown that laser ignition provides a potential means to reduce emissions and improve engine efficiency of gas-fired engines to meet longer-term DOE ARES (Advanced Reciprocating Engine Systems) targets. Despite the potential advantages of laser ignition, the technology is not seeing practical or commercial use. A major impediment in this regard has been the 'open-path' beam delivery used in much of the past research. This mode of delivery is not considered industrially practical owing to safety factors, as well as susceptibility to vibrations, thermal effects etc. The overall goal of our project has been to develop technologies and approaches for practical laser ignition systems. To this end, we are pursuing fiber optically coupled laser ignition system and multiplexing methods for multiple cylinder engine operation. This report summarizes our progress in this regard. A partial summary of our progress includes: development of a figure of merit to guide fiber selection, identification of hollow-core fibers as a potential means of fiber delivery, demonstration of bench-top sparking through hollow-core fibers, single-cylinder engine operation with fiber delivered laser ignition, demonstration of bench-top multiplexing, dual-cylinder engine operation via multiplexed fiber delivered laser ignition, and sparking with fiber lasers. To the best of our knowledge, each of these accomplishments was a first.

  3. The United Nations Global Compact

    DEFF Research Database (Denmark)

    Rasche, Andreas; Waddock, Sandra; McIntosh, Malcolm

    2013-01-01

    This article reviews the interdisciplinary literature on the UN Global Compact. The review identifies three research perspectives, which scholars have used to study the UN Global Compact so far: a historical perspective discussing the Global Compact in the context of UN-business relations, an ope...

  4. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  5. Compact fusion reactors

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  6. Nuclear imaging of the fuel assembly in ignition experiments

    International Nuclear Information System (INIS)

    First results from the analysis of neutron image data collected on implosions of cryogenically layered deuterium-tritium capsules during the 2011-2012 National Ignition Campaign are reported. The data span a variety of experimental designs aimed at increasing the stagnation pressure of the central hotspot and areal density of the surrounding fuel assembly. Images of neutrons produced by deuterium–tritium fusion reactions in the hotspot are presented, as well as images of neutrons that scatter in the surrounding dense fuel assembly. The image data are compared with 1D and 2D model predictions, and consistency checked using other diagnostic data. The results indicate that the size of the fusing hotspot is consistent with the model predictions, as well as other imaging data, while the overall size of the fuel assembly, inferred from the scattered neutron images, is systematically smaller than models' prediction. Preliminary studies indicate these differences are consistent with a significant fraction (20%–25%) of the initial deuterium-tritium fuel mass outside the compact fuel assembly, due either to low mode mass asymmetry or high mode 3D mix effects at the ablator-ice interface

  7. Ignition and timing a guide to rebuilding, repair and replacement

    CERN Document Server

    Beever, Colin

    2015-01-01

    An essential guide to ignition and timing, for classic car owners and restorers. Aimed at both keen amateurs and professionals alike, Ignition and Timing covers the history and evolution of the automotive ignition system, and how to fit, modify and maintain your system for optimum timing and maximum performance. Topics covered include understanding and fault-testing the coil ignition system; post-war distributors and aftermarket systems; how to fit electronic ignitions and modify the distributor, including twin-point distributors; rebuilding and maintenance; Lucas, Delco and Bosch systems

  8. Ignition of organic explosives by an electron beam

    Directory of Open Access Journals (Sweden)

    Ivanov Georgy A.

    2015-01-01

    Full Text Available A numerical simulation of the ignition of organic explosives (PETN, HMX, RDX, TATB with an electron beam was performed. A criterion for the ignition of energetic materials with a melting point below the temperature of ignition is obtained. The results of numerical calculations of the critical energy density of the electron beam are consistent with the criterion of ignition. Calculations of the critical energy density of PETN ignition in good agreement with the experiment. The most sensitive is PETN and the most heat-resistant is TATB.

  9. Compact Quantum Groupoids

    OpenAIRE

    Landsman, N.P.

    1999-01-01

    Quantum groupoids are a joint generalization of groupoids and quantum groups. We propose a definition of a compact quantum groupoid that is based on the theory of C*-algebras and Hilbert bimodules. The essential point is that whenever one has a tensor product over the complex numbers in the theory of quantum groups, one now uses a certain tensor product over the base algebra of the quantum groupoid.

  10. Compactly Generated Domain Theory

    OpenAIRE

    Battenfeld, Ingo; Schröder, Matthias; Simpson, Alexander

    2006-01-01

    We propose compactly generated monotone convergence spaces as a well-behaved topological generalisation of directed-complete partial orders (dcpos). The category of such spaces enjoys the usual properties of categories of 'predomains' in denotational semantics. Moreover, such properties are retained if one restricts to spaces with a countable pseudobase in the sense of E. Michael, a fact that permits connections to be made with computability theory, realizability semantics and recent work on ...

  11. Compact Torsatron configurations

    International Nuclear Information System (INIS)

    Low-aspect-ratio stellarator configurations can be realized by using torsatron winding. Plasmas with aspect ratios in the range of 3.5 to 5 can be confined by these Compact Torsatron configurations. Stable operation at high Β should be possible in these devices, if a vertical field coil system is adequately designed to avoid breaking of the magnetic surfaces at finite Β. 17 refs., 21 figs., 1 tab

  12. Energy report compact 2015

    International Nuclear Information System (INIS)

    The Energy Report compact 2015 from the Ministry of the Environment, Climate Protection and the Energy Sector and the State Office for Statistics Baden-Wuerttemberg provides an overview on the energy sector developments in Baden-Wuerttemberg in 2013. It contains numerous information on the energy consumption in Baden-Wuerttemberg, the energy productivity, the share of renewable energy sources, power generation and the energy-related CO2 emissions.

  13. An expectation on new ignition system of nuclear fusion using petawatt laser

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Ryosuke [Osaka Univ., Suita (Japan). Inst. of Laser Engineering

    2003-02-01

    Fuel pellets used for inertial nuclear fusion are in small size of mm-unit and are compressed to 1,000 times of their densities by using laser and so on, to form nuclear fusion combustion. As their nuclear fusion reactor finishes for about a ten billions seconds, their self combustion is apt to form because of their high density reaction. By repeating some times of this nuclear fusion reaction for a second, energy can be taken out steadily. Then, by using studying method and merits different from a system combusting fuels with relatively large volume for a long time, like conventional engines, comparatively compact and output-variable apparatuses are usable, and by one cycle its physical process finishes. Studies on such laser nuclear fusion has rapidly advanced with advancement of laser technology. Especially, recently, by appearance of a new laser of super high intensity laser, a new ignition system of nuclear fusion called by fast ignition approaches to its practice. Success of this system will bring feasibility to realize a compact and economical nuclear fusion reactor, to make a route suitable for development of nuclear fusion energy. (G.K.)

  14. Ignition Characteristics of Premixed Methane/air in Micro Chamber

    International Nuclear Information System (INIS)

    The ignition process of premixed methane/air in a micro-scale chamber is simulated with the combination of surface chemistry and gas-phase reactions. The effect of different parameters on the ignition characteristics are analyzed in detail and the sensitive analysis is performed on main elementary reactions. It is found that the ignition of the mixture is inhibited by surface reaction, which mainly depends on the sticking ability of the surface on CH3 radical. The ignition inhibition can be reduced by increasing the initial temperature and pressure. The increase of equivalence ratio has small impact on ignition delay time when it is larger than stoichiometric ratio. The ignition delay time would increase significantly with surface-area-to- volume ratio. The product of sticking coefficient and surface-area-to-volume ratio can be used to measure the intensity of surface reaction. The larger the product is, the stronger the inhibition of the surface reaction on ignition has

  15. Advances for laser ignition of internal combustion and rocket engines

    International Nuclear Information System (INIS)

    The scope of the PhD thesis presented here is the investigation of theoretical and practical aspects of laser-induced spark ignition and laser thermal ignition. Laser ignition systems are currently undergoing a rapidly development with growing intensity involving more and more research groups who mainly concentrate on the field of car and large combustion engines. This research is primarily driven by the engagement to meet the increasingly strict emission limits and by the intention to use the limited energy reserves more efficiently. For internal combustion engines, laser plasma-induced ignition will allow to combine the goals for legally required reductions of pollutant emissions and higher engine efficiencies. Also for rocket engines laser ignition turns out to be very attractive. A highly reliable ignition system like laser ignition would represent an option for introducing non-toxic propellants in order to replace highly toxic and carcinogenic hydrazine-based propellants commonly used in launch vehicle upper stages and satellites. The most important results on laser ignition and laser plasma generation, accomplished by the author and, in some respects, enriched by cooperation with colleagues are presented in the following. The emphasis of this thesis is placed on the following issues: - Two-color effects on laser plasma generation - Theoretical considerations about the focal volume concerning plasma generation - Plasma transmission experiments - Ignition experiments on laser-induced ignition - Ignition experiments on thermally-induced ignition - Feasibility study on laser ignition of rocket engines The purpose of the two-color laser plasma experiments is to investigate possible constructive interference effects of driving fields that are not monochromatic, but contain (second) harmonic radiation with respect to the goal of lowering the plasma generation threshold. Such effects have been found in a number of related processes, such as laser ablation or high

  16. Fast Ignition Experimental and Theoretical Studies

    Energy Technology Data Exchange (ETDEWEB)

    Akli, K

    2006-10-20

    We are becoming dependent on energy more today than we were a century ago, and with increasing world population and booming economies, sooner or later our energy sources will be exhausted. Moreover, our economy and welfare strongly depends on foreign oil and in the shadow of political uncertainties, there is an urgent need for a reliable, safe, and cheap energy source. Thermonuclear fusion, if achieved, is that source of energy which not only will satisfy our demand for today but also for centuries to come. Today, there are two major approaches to achieve fusion: magnetic confinement fusion (MFE) and inertial confinement fusion (ICF). This dissertation explores the inertial confinement fusion using the fast ignition concept. Unlike the conventional approach where the same laser is used for compression and ignition, in fast ignition separate laser beams are used. This dissertation addresses three very important topics to fast ignition inertial confinement fusion. These are laser-to-electron coupling efficiency, laser-generated electron beam transport, and the associated isochoric heating. First, an integrated fast ignition experiment is carried out with 0.9 kJ of energy in the compression beam and 70 J in the ignition beam. Measurements of absolute K{sub {alpha}} yield from the imploded core revealed that about 17% of the laser energy is coupled to the suprathermal electrons. Modeling of the transport of these electrons and the associated isochoric heating, with the previously determined laser-to-electron conversion efficiency, showed a maximum target temperature of 166 eV at the front where the electron flux is higher and the density is lower. The contribution of the potential, induced by charge separation, in opposing the motion of the electrons was moderate. Second, temperature sensitivity of Cu K{sub {alpha}} imaging efficiency using a spherical Bragg reflecting crystal is investigated. It was found that due to the shifting and broadening of the K{sub {alpha

  17. How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters.

    Science.gov (United States)

    Leins, Martina; Gaiser, Sandra; Schulz, Andreas; Walker, Matthias; Schumacher, Uwe; Hirth, Thomas

    2015-01-01

    This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a stable and continuous operation of the plasma is possible and the plasma torch can be used for many different applications. On one hand, the hot (3,600 K gas temperature) plasma can be used for chemical processes and on the other hand the cold afterglow (temperatures down to almost RT) can be applied for surface processes. For example chemical syntheses are interesting volume processes. Here the microwave plasma torch can be used for the decomposition of waste gases which are harmful and contribute to the global warming but are needed as etching gases in growing industry sectors like the semiconductor branch. Another application is the dissociation of CO2. Surplus electrical energy from renewable energy sources can be used to dissociate CO2 to CO and O2. The CO can be further processed to gaseous or liquid higher hydrocarbons thereby providing chemical storage of the energy, synthetic fuels or platform chemicals for the chemical industry. Applications of the afterglow of the plasma torch are the treatment of surfaces to increase the adhesion of lacquer, glue or paint, and the sterilization or decontamination of different kind of surfaces. The movie will explain how to ignite the plasma solely by microwave power without any additional igniters, e.g., electric sparks. The microwave plasma torch is based on a combination of two resonators - a coaxial one which provides the ignition of the plasma and a cylindrical one which guarantees a continuous and stable operation of the plasma after ignition. The plasma can be operated in a long microwave transparent tube for volume processes or shaped by orifices for surface treatment purposes. PMID:25938699

  18. Dopaminergic dysfunction and psychiatric symptoms in movement disorders: a {sup 123}I-FP-CIT SPECT study

    Energy Technology Data Exchange (ETDEWEB)

    Di Giuda, Daniela; Cocciolillo, Fabrizio; Bruno, Isabella; Giordano, Alessandro [Universita Cattolica del Sacro Cuore, Istituto di Medicina Nucleare, Rome (Italy); Camardese, Giovanni; Pucci, Lorella; Janiri, Luigi [Universita Cattolica del Sacro Cuore, Istituto di Psichiatria e Psicologia, Rome (Italy); Bentivoglio, Anna Rita; Guidubaldi, Arianna [Universita Cattolica del Sacro Cuore, Istituto di Neurologia, Rome (Italy); Fasano, Alfonso [Universita Cattolica del Sacro Cuore, Istituto di Neurologia, Rome (Italy); AFaR-Associazione Fatebenefratelli per la Ricerca, Rome (Italy)

    2012-12-15

    Psychiatric symptoms frequently occur in patients with movement disorders. They are not a mere reaction to chronic disability, but most likely due to a combination of psychosocial factors and biochemical dysfunction underlying the movement disorder. We assessed dopamine transporter (DAT) availability by means of {sup 123}I-FP-CIT SPECT, and motor and psychiatric features in patients with Parkinson's disease, primary dystonia and essential tremor, exploring the association between SPECT findings and symptom severity. Enrolled in the study were 21 patients with Parkinson's disease, 14 patients with primary dystonia and 15 patients with essential tremor. The severity of depression symptoms was assessed using the Hamilton depression rating scale, anxiety levels using the Hamilton anxiety rating scale and hedonic tone impairment using the Snaith-Hamilton pleasure scale. Specific {sup 123}I-FP-CIT binding in the caudate and putamen was calculated based on ROI analysis. The control group included 17 healthy subjects. As expected, DAT availability was significantly decreased in patients with Parkinson's disease, whereas in essential tremor and dystonia patients it did not differ from that observed in the control group. In Parkinson's disease patients, an inverse correlation between severity of depression symptoms and DAT availability in the left caudate was found (r = -0.63, p = 0.002). In essential tremor patients, levels of anxiety symptoms were inversely correlated with DAT availability in the left caudate (r = -0.69, p = 0.004). In dystonia patients, the severities of both anxiety and depression symptoms were inversely associated with DAT availability in the left putamen (r = -0.71, p = 0.004, and r = -0.75, p = 0.002, respectively). There were no correlations between psychometric scores and {sup 123}I-FP-CIT uptake ratios in healthy subjects. We found association between presynaptic dopaminergic function and affective symptoms in different movement

  19. RGDechi-hCit: αvβ3 selective pro-apoptotic peptide as potential carrier for drug delivery into melanoma metastatic cells.

    Directory of Open Access Journals (Sweden)

    Domenica Capasso

    Full Text Available αvβ3 integrin is an important tumor marker widely expressed on the surface of cancer cells. Recently, we reported some biological features of RGDechi-hCit, an αvβ3 selective peptide antagonist. In the present work, we mainly investigated the pro-apoptotic activity of the molecule and its ability to penetrate the membrane of WM266 cells, human malignant melanoma cells expressing high levels of αvβ3 integrin. For the first time we demonstrated the pro-apoptotic effect and the ability of RGDechi-hCit to enter into cell overexpressing αvβ3 integrin mainly by clathrin- and caveolin-mediated endocytosis. Furthermore, we deepened and confirmed the selectivity, anti-adhesion, and anti-proliferative features of the peptide. Altogether these experiments give insight into the biological behavior of RGDechi-hCit and have important implications for the employment of the peptide as a new selective carrier to deliver drugs into the cell and as a therapeutic and diagnostic tool for metastatic melanoma. Moreover, since the peptide shows a pro-apoptotic effect, a great perspective could be the development of a new class of selective systems containing RGDechi-hCit and pro-apoptotic molecules or other therapeutic agents to attain a synergic action.

  20. A Combined NMR and Computational Approach to Determine the RGDechi-hCit-αv β3 Integrin Recognition Mode in Isolated Cell Membranes.

    Science.gov (United States)

    Farina, Biancamaria; de Paola, Ivan; Russo, Luigi; Capasso, Domenica; Liguoro, Annamaria; Gatto, Annarita Del; Saviano, Michele; Pedone, Paolo V; Di Gaetano, Sonia; Malgieri, Gaetano; Zaccaro, Laura; Fattorusso, Roberto

    2016-01-11

    The critical role of integrins in tumor progression and metastasis has stimulated intense efforts to identify pharmacological agents that can modulate integrin function. In recent years, αv β3 and αv β5 integrin antagonists were demonstrated to be effective in blocking tumor progression. RGDechi-hCit, a chimeric peptide containing a cyclic RGD motif linked to an echistatin C-terminal fragment, is able to recognize selectively αv β3 integrin both in vitro and in vivo. High-resolution molecular details of the selective αv β3 recognition of the peptide are certainly required, nonetheless RGDechi-hCit internalization limited the use of classical in cell NMR experiments. To overcome such limitations, we used WM266 isolated cellular membranes to accomplish a detailed NMR interaction study that, combined with a computational analysis, provides significant structural insights into αv β3 molecular recognition by RGDechi-hCit. Remarkably, on the basis of the identified molecular determinants, we design a RGDechi-hCit mutant that is selective for αv β5 integrin. PMID:26548575

  1. Automatic semi-quantification of [(123)I]FP-CIT SPECT scans in healthy volunteers using BasGan version 2

    DEFF Research Database (Denmark)

    Nobili, Flavio; Naseri, Mehrdad; De Carli, Fabrizio; Asenbaum, Susan; Booij, Jan; Darcourt, Jacques; Ell, Peter; Kapucu, Ozlem; Kemp, Paul; Svarer, Claus; Morbelli, Silvia; Pagani, Marco; Sabri, Osama; Tatsch, Klaus; Tossici-Bolt, Livia; Sera, Terez; Borght, Tierry Vander; Van Laere, Koen; Varrone, Andrea

    2013-01-01

    Medicine). Brain single photon emission computed tomography (SPECT) was acquired by means of dual-head cameras 3 h after [(123)I]FP-CIT administration. Specific to nondisplaceable binding ratios (SBRs) in the basal ganglia were computed using the 'BasGan' software, allowing automatic value extraction with...

  2. Clinical features and {sup 123}I-FP-CIT SPECT imaging in drug-induced parkinsonism and Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Corrales, Francisco J.; Escobar-Delgado, Teresa [Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurologia, Instituto de Biomedicina de Sevilla, Seville (Spain); Sanz-Viedma, Salome [Hospital Universitario Virgen del Rocio, Unidad Diagnostica de Medicina Nuclear, Seville (Spain); Garcia-Solis, David [Hospital Universitario Virgen del Rocio, Unidad Diagnostica de Medicina Nuclear, Seville (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Seville (Spain); Mir, Pablo [Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Unidad de Trastornos del Movimiento, Servicio de Neurologia, Instituto de Biomedicina de Sevilla, Seville (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Seville (Spain); Hospital Universitario Virgen del Rocio, Unidad de Trastornos del Movimiento. Servicio de Neurologia, Seville (Spain)

    2010-03-15

    To determine clinical predictors and accuracy of {sup 123}I-FP-CIT SPECT imaging in the differentiation of drug-induced parkinsonism (DIP) and Parkinson's disease (PD). Several clinical features and {sup 123}I-FP-CIT SPECT images in 32 patients with DIP, 25 patients with PD unmasked by antidopaminergic drugs (PDu) and 22 patients with PD without a previous history of antidopaminergic treatment (PDc) were retrospectively evaluated. DIP and PD shared all clinical features except symmetry of parkinsonian signs which was more frequently observed in patients with DIP (46.9%) than in patients with PDu (16.0%, p<0.05) or PDc (4.5%, p<0.01). Qualitatively {sup 123}I-FP-CIT SPECT images were normal in 29 patients with DIP (90.6%) and abnormal in all patients with PD, and this imaging technique showed high levels of accuracy. DIP and PD are difficult to differentiate based on clinical signs. The precision of clinical diagnosis could be reliably enhanced by {sup 123}I-FP-CIT SPECT imaging. (orig.)

  3. Los medios de comunicación del Instituto Tecnológico de Costa Rica. El Centro de Información Tecnológica (CIT)

    OpenAIRE

    Lic. Annie Badilla Calderón

    1999-01-01

    Aquí se pretende poner en evidencia el estado actual del CIT (Centro de Investigación Tecnológica) como medio de comunicación y de investigación. Los datos se tomaron de entrevistas realizadas a las personas que conforman el grupo de trabajo de esta oficina.

  4. The clinical benefit of imaging striatal dopamine transporters with [123I]FP-CIT SPET in differentiating patients with presynaptic parkinsonism from those with other forms of parkinsonism

    International Nuclear Information System (INIS)

    [123I]FP-CIT (N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane) has been developed successfully as a radioligand for single-photon emission tomography (SPET) imaging of dopamine transporters, which are situated in the membrane of dopaminergic neurons. Imaging of these transporters has shown promise as a clinical tool to detect degeneration of the dopaminergic nigrostriatal pathway. Several ''presynaptic parkinsonian'' syndromes, such as Parkinson's disease or multiple system atrophy, are characterised by degeneration of the nigrostriatal pathway. [123I]FP-CIT SPET imaging studies have shown the ability to detect loss of striatal dopamine transporters in such syndromes. However, in clinical practice it is sometimes difficult, but important, to discriminate patients with ''presynaptic parkinsonism'' from those with other forms of parkinsonism not characterised by loss of presynaptic dopaminergic cells (e.g. psychogenic parkinsonism or drug-induced postsynaptic parkinsonism). In these inconclusive cases, it may be of value to confirm or exclude the existence of degeneration of nigrostriatal dopaminergic cells by using imaging techniques such as [123I]FP-CIT SPET. Using [123I]FP-CIT SPET, we have imaged the striatal dopamine transporters in a group of patients with inconclusive forms of parkinsonism, and, moreover, have been able to perform clinical follow-up of these patients 2-4 years after imaging. In 33 inconclusive cases, ratios of specific to non-specific binding were calculated for the caudate nucleus and putamen following [123I]FP-CIT SPET imaging and compared with ratios obtained in healthy controls. In nine of the patients, degeneration of the nigrostriatal pathway was found scintigraphically and in all these cases, presynaptic parkinsonism was confirmed by clinical follow-up. In the other 24 subjects no degeneration was found scintigraphically. Forms of parkinsonism other than the presynaptic were confirmed at follow-up in 19 cases, and in

  5. Compact synchrotron radiation source

    International Nuclear Information System (INIS)

    A compact 800 MeV synchrotron radiation source is discussed. The storage ring has a circumference of 30.3 m, two 90 degree and four 45 degree bending magnet sections, two long straight sections and four short straight sections. The radius of the bending magnet is 2.224m. The critical wave length is 24A. The injector is a 15 Mev Microtron Electrons are accelerated from 15 Mev to 800 Mev by ramping the field of the ring. The expected stored current will be around 100 ma

  6. Atacama Compact Array Antennas

    OpenAIRE

    Saito, Masao; Inatani, Junji; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high...

  7. Compact Q-balls

    CERN Document Server

    Bazeia, D; Marques, M A; Menezes, R; da Rocha, R

    2016-01-01

    In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  8. Ignition on the National Ignition Facility: a path towards inertial fusion energy

    Science.gov (United States)

    Moses, Edward I.

    2009-10-01

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

  9. Ignition on the National Ignition Facility: a path towards inertial fusion energy

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

  10. Laser-plasma interactions for fast ignition

    CERN Document Server

    Kemp, A J; Debayle, A; Johzaki, T; Mori, W B; Patel, P K; Sentoku, Y; Silva, L O

    2013-01-01

    In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multi-dimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the compa...

  11. Stable transport in proton driven Fast Ignition

    CERN Document Server

    Bret, A

    2009-01-01

    Proton beam transport in the context of proton driven Fast Ignition is usually assumed to be stable due to protons high inertia, but an analytical analysis of the process is still lacking. The stability of a charge and current neutralized proton beam passing through a plasma is therefore conducted here, for typical proton driven Fast Ignition parameters. In the cold regime, two fast growing Buneman-like modes are found, with an inverse growth-rate much smaller than the beam time-of-flight to the target core. The stability issue is thus not so obvious, and Kinetic effects are investigated. One unstable mode is found stabilized by the background plasma protons and electrons temperatures. The second mode is also damped, providing the proton beam thermal spread is larger than $\\sim$ 10 keV. In Fusion conditions, the beam propagation should therefore be stable.

  12. Test report for core drilling ignitability testing

    International Nuclear Information System (INIS)

    Testing was carried out with the cooperation of Westinghouse Hanford Company and the United States Bureau of Mines at the Pittsburgh Research Center in Pennsylvania under the Memorandum of Agreement 14- 09-0050-3666. Several core drilling equipment items, specifically those which can come in contact with flammable gasses while drilling into some waste tanks, were tested under conditions similar to actual field sampling conditions. Rotary drilling against steel and rock as well as drop testing of several different pieces of equipment in a flammable gas environment were the specific items addressed. The test items completed either caused no ignition of the gas mixture, or, after having hardware changes or drilling parameters modified, produced no ignition in repeat testing

  13. Conceptual Design - Polar Drive Ignition Campaign

    International Nuclear Information System (INIS)

    The Laboratory for Laser Energetics (LLE) at the University of Rochester is proposing a collaborative effort with Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratories (LANL), the Naval Research Laboratory (NRL), and General Atomics (GA) with the goal of developing a cryogenic polar drive (PD) ignition platform on the National Ignition Facility (NIF). The scope of this proposed project requires close discourse among theorists, experimentalists, and laser and system engineers. This document describes how this proposed project can be broken into a series of parallel independent activities that, if implemented, could deliver this goal in the 2017 timeframe. This Conceptual Design document is arranged into two sections: mission need and design requirements. Design requirements are divided into four subsystems: (1) A point design that details the necessary target specifications and laser pulse requirements; (2) The beam smoothing subsystem that describes the MultiFM 1D smoothing by spectral dispersion (SSD); (3) New optical elements that include continuous phase plates (CPP's) and distributed polarization rotators (DPR's); and (4) The cryogenic target handling and insertion subsystem, which includes the design, fabrication, testing, and deployment of a dedicated PD ignition target insertion cryostat (PD-ITIC). This document includes appendices covering: the primary criteria and functional requirements, the system design requirements, the work breakdown structure, the target point design, the experimental implementation plan, the theoretical unknowns and technical implementation risks, the estimated cost and schedule, the development plan for the DPR's, the development plan for MultiFM 1D SSD, and a list of acronym definitions. While work on the facility modifications required for PD ignition has been in progress for some time, some of the technical details required to define the specific modifications for a Conceptual Design Review (CDR) remain

  14. Preignition processes in laser ignition of pyrotechnics

    International Nuclear Information System (INIS)

    IR Fourier spectroscopy and differential scanning calorimetry were used to study preignition processes in pure pyrotechnic mixtures KClO3-B(85/15), KClO4-B(78/22), BaClO4-B(95/5), K2Cr2O7-W(65/35) under CO2 laser pulse radiation. Comparative optical, kinetic and thermodynamic characteristics of the initial and irradiated samples suggest that intense photochemical decay of oxidizer molecules can occur under laser radiation and result in a significant decrease in laser ignition temperature and time delay. A direct correlation is revealed between the sensitivity of the mixtures to laser ignition and the character of the changes in the characteristics of solid-phase reactions in irradiated samples

  15. Plasma Properties of an Exploding Semiconductor Igniter

    Science.gov (United States)

    McGuirk, J. S.; Thomas, K. A.; Shaffer, E.; Malone, A. L.; Baginski, T.; Baginski, M. E.

    1997-11-01

    Requirements by the automotive industry for low-cost, pyrotechnic igniters for automotive airbags have led to the development of several semiconductor devices. The properties of the plasma produced by the vaporization of an exploding semiconductor are necessary in order to minimize the electrical energy requirements. This work considers two silicon-based semiconductor devices: the semiconductor bridge (SCB) and the semiconductor junction igniter both consisting of etched silicon with vapor deposited aluminum structures. Electrical current passing through the device heats a narrow junction region to the point of vaporization creating an aluminum and silicon low-temperature plasma. This work will investigate the electrical characteristics of both devices and infer the plasma properties. Furthermore optical spectral measurements will be taken of the exploding devices to estimate the temperature and density of the plasma.

  16. Conceptual Design - Polar Drive Ignition Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, R

    2012-04-05

    The Laboratory for Laser Energetics (LLE) at the University of Rochester is proposing a collaborative effort with Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratories (LANL), the Naval Research Laboratory (NRL), and General Atomics (GA) with the goal of developing a cryogenic polar drive (PD) ignition platform on the National Ignition Facility (NIF). The scope of this proposed project requires close discourse among theorists, experimentalists, and laser and system engineers. This document describes how this proposed project can be broken into a series of parallel independent activities that, if implemented, could deliver this goal in the 2017 timeframe. This Conceptual Design document is arranged into two sections: mission need and design requirements. Design requirements are divided into four subsystems: (1) A point design that details the necessary target specifications and laser pulse requirements; (2) The beam smoothing subsystem that describes the MultiFM 1D smoothing by spectral dispersion (SSD); (3) New optical elements that include continuous phase plates (CPP's) and distributed polarization rotators (DPR's); and (4) The cryogenic target handling and insertion subsystem, which includes the design, fabrication, testing, and deployment of a dedicated PD ignition target insertion cryostat (PD-ITIC). This document includes appendices covering: the primary criteria and functional requirements, the system design requirements, the work breakdown structure, the target point design, the experimental implementation plan, the theoretical unknowns and technical implementation risks, the estimated cost and schedule, the development plan for the DPR's, the development plan for MultiFM 1D SSD, and a list of acronym definitions. While work on the facility modifications required for PD ignition has been in progress for some time, some of the technical details required to define the specific modifications for a Conceptual Design

  17. Transport Simulations for Fast Ignition on NIF

    Energy Technology Data Exchange (ETDEWEB)

    Strozzi, D J; Tabak, M; Grote, D P; Cohen, B I; Shay, H D; Town, R J; Kemp, A J; Key, M

    2009-10-26

    We are designing a full hydro-scale cone-guided, indirect-drive FI coupling experiment, for NIF, with the ARC-FIDO short-pulse laser. Current rad-hydro designs with limited fuel jetting into cone tip are not yet adequate for ignition. Designs are improving. Electron beam transport simulations (implicit-PIC LSP) show: (1) Magnetic fields and smaller angular spreads increase coupling to ignition-relevant 'hot spot' (20 um radius); (2) Plastic CD (for a warm target) produces somewhat better coupling than pure D (cryogenic target) due to enhanced resistive B fields; and (3) The optimal T{sub hot} for this target is {approx} 1 MeV; coupling falls by 3x as T{sub hot} rises to 4 MeV.

  18. Preliminary results of thermal igniter experiments

    International Nuclear Information System (INIS)

    Thermal igniters (glow plugs), proposed by the Tennessee Valley Authority for intentional ignition of hydrogen in nuclear reactor containment, have been tested for functionability in mixtures of air, hydrogen, and steam. Test environments included 6% to 16% hydrogen concentrations in air, and 8%, 10%, and 12% hydrogen in mixtures with 30% and 40% steam functions. All were conducted in a 10.6 ft3 insulated pressure vessel. For all of these tests the glow plug successfully initiated combustion. Dry air/hydrogen tests exhibited a distinct tendency for complete combustion at hydrogen concentrations between 8% and 9%. Steam suppressed both peak pressures and completeness of combustion. No combustion could be initiated at or above a 50% steam fraction. Circulation of the mixture with a fan increased the completeness of combustion. The glow plug showed no evidence of performance degradation throughout the program

  19. Integrated thermodynamic model for ignition target performance

    Directory of Open Access Journals (Sweden)

    Springer P.T.

    2013-11-01

    Full Text Available We have derived a 3-dimensional synthetic model for NIF implosion conditions, by predicting and optimizing fits to a broad set of x-ray and nuclear diagnostics obtained on each shot. By matching x-ray images, burn width, neutron time-of-flight ion temperature, yield, and fuel ρr, we obtain nearly unique constraints on conditions in the hotspot and fuel in a model that is entirely consistent with the observables. This model allows us to determine hotspot density, pressure, areal density (ρr, total energy, and other ignition-relevant parameters not available from any single diagnostic. This article describes the model and its application to National Ignition Facility (NIF tritium–hydrogen–deuterium (THD and DT implosion data, and provides an explanation for the large yield and ρr degradation compared to numerical code predictions.

  20. Ignition study of a petrol/CNG single cylinder engine

    Science.gov (United States)

    Khan, N.; Saleem, Z.; Mirza, A. A.

    2005-11-01

    Benefits of laser ignition over the electrical ignition system for Compressed Natural Gas (CNG) engines have fuelled automobile industry and led to an extensive research on basic characteristics to switch over to the emerging technologies. This study was undertaken to determine the electrical and physical characteristics of the electric spark ignition of single cylinder petrol/CNG engine to determine minimum ignition requirements and timeline of ignition events to use in subsequent laser ignition study. This communication briefly reviews the ongoing research activities and reports the results of this experimental study. The premixed petrol and CNG mixtures were tested for variation of current and voltage characteristics of the spark with speed of engine. The current magnitude of discharge circuit was found to vary linearly over a wide range of speed but the stroke to stroke fire time was found to vary nonlinearly. The DC voltage profiles were observed to fluctuate randomly during ignition process and staying constant in rest of the combustion cycle. Fire to fire peaks of current amplitudes fluctuated up to 10% of the peak values at constant speed but increased almost linearly with increase in speed. Technical barriers of laser ignition related to threshold minimum ignition energy, inter-pulse durations and firing sequence are discussed. Present findings provide a basic initiative and background information for designing suitable timeline algorithms for laser ignited leaner direct injected CNG engines.

  1. Investigating antennas as ignition aid for automotive HID lamps

    International Nuclear Information System (INIS)

    This paper considers the ignition of mercury-free high-intensity discharge (HID) lamps for car headlights. Due to safety reasons, these lamps need to have a fast run-up phase which is ensured, amongst other things, by a high Xe pressure of roughly 15 bar (cold) in the discharge vessel. The high Xe pressure causes an increased ignition voltage compared with former mercury-containing automotive HID lamps or low-pressure lamps used for general-lighting applications. The increase in ignition voltage can be limited if the electric field in front of the electrodes is raised by an uplifting of the electrical conductivity along the outer wall of the inner bulb either by a conductive layer on its surface or by a dielectric barrier discharge (DBD) within the outer bulb. This paper considers on the one hand conventional antennas deposited by physical vapour deposition (PVD) and on the other hand a combination of these antennas with a DBD within the outer-bulb operated in 100 mbar Ar as ignition aids. In both cases the antenna potential and antenna width are varied. Additionally, the effects of antenna thickness and antenna material are investigated. The ignition voltage, ignition current and light emission during ignition are measured on a nanosecond timescale. Furthermore, for the very first time, the ignition process is recorded in four consecutive intensified charge-coupled device images using a high-speed camera system with a time resolution in the range of nanoseconds. It was found that antennas strongly reduce the ignition voltage of automotive HID lamps. Active antennas reduce the ignition voltage significantly more than passive antennas, proportional to the conductance of the antenna. Combining conventional antennas with an outer-bulb discharge reduces the ignition voltage from 19 kV without any ignition aid to the intrinsic ignition voltage of the lamp below 10 kV, in the best case. (paper)

  2. Lower hybrid heating of tokamaks to ignition

    International Nuclear Information System (INIS)

    The incorporation of a quasi-linear collisional wave damping model of lower hybrid electron heating into a radial transport code reveals favourable prospects for heating tokamak plasmas to ignition. The RF frequencies considered here are such that the wave interaction is primarily with the electrons. For a particular test reactor design, 30 MW of lower hybrid power used in conjunction with a programmed plasma density start-up suffices to initiate a self-sustained thermonuclear burn. (author)

  3. IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    Jason M. Keith

    2005-02-01

    This report describes work performed during a thirty month project which involves the production of dimethyl ether (DME) on-site for use as an ignition-improving additive in a compression-ignition natural gas engine. A single cylinder spark ignition engine was converted to compression ignition operation. The engine was then fully instrumented with a cylinder pressure transducer, crank shaft position sensor, airflow meter, natural gas mass flow sensor, and an exhaust temperature sensor. Finally, the engine was interfaced with a control system for pilot injection of DME. The engine testing is currently in progress. In addition, a one-pass process to form DME from natural gas was simulated with chemical processing software. Natural gas is reformed to synthesis gas (a mixture of hydrogen and carbon monoxide), converted into methanol, and finally to DME in three steps. Of additional benefit to the internal combustion engine, the offgas from the pilot process can be mixed with the main natural gas charge and is expected to improve engine performance. Furthermore, a one-pass pilot facility was constructed to produce 3.7 liters/hour (0.98 gallons/hour) DME from methanol in order to characterize the effluent DME solution and determine suitability for engine use. Successful production of DME led to an economic estimate of completing a full natural gas-to-DME pilot process. Additional experimental work in constructing a synthesis gas to methanol reactor is in progress. The overall recommendation from this work is that natural gas to DME is not a suitable pathway to improved natural gas engine performance. The major reasons are difficulties in handling DME for pilot injection and the large capital costs associated with DME production from natural gas.

  4. SPECT imaging using [{sup 123}I]{beta}-CIT and [{sup 123}I]IBF in extrapyramidal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takahiro; Amano, Takahiro; Hashimoto, Jun; Itoh, Yoshiaki; Muramatsu, Kazuhiro; Kubo, Atsushi; Fukuuchi, Yasuo [Keio Univ., Tokyo (Japan). School of Medicine

    2003-01-01

    Imaging of dopaminergic function is useful in the investigation of patients with Parkinson disease (iPD) and other extrapyramidal diseases. Using agents that bind to dopamine transporters ([{sup 123}I]{beta}-CIT) and receptors ([{sup 123}I]IBF SPECT), we investigated SPECT in 9 healthy volunteers and 24 patients for dopamine transporters as well as 15 patients for dopamine receptors. In {beta}-CIT SPECT studies, we examined 17 iPD patients (63.3{+-}9.9 y/o), 3 multiple system atrophy (MSA) patients (olivopontocerebellar atrophy (OPCA) type) (64.0{+-}8.0 y/o), 2 vascular parkinsonism (VP) patients (71.0{+-}0.0 y/o), 1 progressive supranuclear palsy (PSP) patient (69 y/o), 1 cortico-basal degeneration (CBD) patient (50 y/o) and nine healthy controls (39.1{+-}9.3 y/o). For IBF SPECT studies 11 iPD patients (60.6{+-}10.9 y/o), 3 MSA patients (2 OPCA type (50.5{+-}3.5 y/o) and 1 striatonigral degeneration (SND) type (65 y/o)) and 1 PSP patient (60 y/o) underwent SPECT scans after the injection of [{sup 123}I]IBF. The specific to nonspecific striatal ratio (St/Oc-1), ratio of putaminal uptake to caudatal uptake (Pu/Ca), and asymmetry indices (AI) were estimated. {beta}-CIT studies showed ST/Oc-1 as follows; iPD: 2.66{+-}1.09 (n=17), VP: 5.73 and 7.39, MSA: 1.84{+-}0.46 (n=3), PSP: 2.34, CBD: 2.16. In all extrapyramidal diseases except VP, St/Oc-1 ratios were significantly lower than those in normal volunteers (6.46{+-}1.08) (p<0.01). Also in early-phase iPD patients (Yahr I-II), St/Oc-1 (3.16{+-}1.49: n=4) was significantly lower than those in normal volunteers (p<0.01). In IBF studies, St/Oc-1 ratios were significantly higher in early-phase (Yahr I-II) iPD patients (1.82{+-}0.25: n=5) than those in late-phase (Yahr III-IV) iPD patients (1.38{+-}0.32: n=6) (p<0.05). The Pu/Ca ratios in iPD patients (1.12{+-}0.13) and MSA (OPCA type) patients (0.95{+-}0.05) were higher than that in MSA (SND type) patient (0.78) and were lower than that in PSP patient (1.55). In conclusion

  5. De la laïcité en Islam selon Mohammad Abid Al-Jâbirî

    OpenAIRE

    Dourari, Abderrezak

    2013-01-01

    Le terme de « laïcité », attribut de la modernité dans le monde occidental, est frappé d’anathème dans le Monde arabe et islamique. Il est même pris curieusement pour synonyme d’athéisme. Mohammed Abid Al-Jâbirî, philosophe marocain, lui consacre un article entier et semble, probablement dans une visée tactique, vouloir contourner ce terme fortement connoté en proposant de le remplacer par « démocratie » et « rationalisme ». Pour montrer que ce terme suscite une fausse problématique et est « ...

  6. Le rôle du récit de vie dans le discours politique de Lula

    OpenAIRE

    Machado, Ida Lucia

    2011-01-01

    Cet article propose une réflexion sur le rôle du récit de vie dans les discours politiques, et plus précisément dans les discours d’investiture à la présidence du Brésil de Luis Ignacio Lula da Silva. Il analyse quelques fragments qui mêlent expressément des souvenirs de sa vie passée aux discours politiques d’actualité, mais aussi qui font allusion à sa vie de façon indirecte. Dans le premier discours, Lula se présente comme un personnage de l’histoire, un « il » qui veut travailler pour la ...

  7. Cités, citoyenneté et territorialité dans l’île de Ngazidja (Comores)

    OpenAIRE

    Blanchy, Sophie

    2007-01-01

    Dans l’île de Ngazidja (Comores), les cités, organisées selon une hiérarchie complexe mêlant divisions sociales, lignages, classes d’âge, constituent des unités politiques et territoriales fortes. Elles ont survécu à la royauté puis à la colonisation et se maintiennent face aux institutions de l’État moderne. La hiérarchie qui règle encore les rapports sociaux a des effets sur l’accès à la citoyenneté et sur les modes d’assemblée, perceptibles jusque dans l’organisation de la migration des Co...

  8. L’univers du récit d’enquête d’Agatha Christie à Rodolfo Walsh

    Directory of Open Access Journals (Sweden)

    José García-Romeu

    2009-10-01

    Full Text Available En tant que sous-genre spécifique, le récit d’enquête respecte des prescriptions assez constantes qui participent à l’élaboration d’un univers fictionnel particulièrement bien réglé. Agatha Christie offre par exemple un modèle très efficace où chaque élément participe à imposer un système qui, du fait de son renforcement par la répétition, atteint un caractère rituel. L’écrivain argentin Rodolfo Walsh a composé une œuvre qui joue habilement avec ces règles, soit pour les réduire à une épure abstraite, soit pour les trahir.

  9. Validation of simple quantification methods for 18F FP CIT PET Using Automatic Delineation of volumes of interest based on statistical probabilistic anatomical mapping and isocontour margin setting

    International Nuclear Information System (INIS)

    18F FP CIT positron emission tomography (PET) is an effective imaging for dopamine transporters. In usual clinical practice, 18F FP CIT PET is analyzed visually or quantified using manual delineation of a volume of interest (VOI) fir the stratum. in this study, we suggested and validated two simple quantitative methods based on automatic VOI delineation using statistical probabilistic anatomical mapping (SPAM) and isocontour margin setting. Seventy five 18F FP CIT images acquired in routine clinical practice were used for this study. A study-specific image template was made and the subject images were normalized to the template. afterwards, uptakes in the striatal regions and cerebellum were quantified using probabilistic VOI based on SPAM. A quantitative parameter, QSPAM, was calculated to simulate binding potential. additionally, the functional volume of each striatal region and its uptake were measured in automatically delineated VOI using isocontour margin setting. Uptake volume product(QUVP) was calculated for each striatal region. QSPAMand QUVPwas calculated for each visual grading and the influence of cerebral atrophy on the measurements was tested. Image analyses were successful in all the cases. Both the QSPAMand QUVPwere significantly different according to visual grading (0.001). The agreements of QUVPand QSPAMwith visual grading were slight to fair for the caudate nucleus (K= 0.421 and 0.291, respectively) and good to prefect to the putamen (K=0.663 and 0.607, respectively). Also, QSPAMand QUVPhad a significant correlation with each other (0.001). Cerebral atrophy made a significant difference in QSPAMand QUVPof the caudate nuclei regions with decreased 18F FP CIT uptake. Simple quantitative measurements of QSPAMand QUVPshowed acceptable agreement with visual grad-ing. although QSPAMin some group may be influenced by cerebral atrophy, these simple methods are expected to be effective in the quantitative analysis of F FP CIT PET in usual clinical

  10. Concept of laser fusion power plant based on fast ignition

    International Nuclear Information System (INIS)

    This paper introduces new concept of laser fusion that is expected to demonstrate energy generation based on inertial fusion in the near future. In the fast ignition (FI) scheme, a spherical hollow solid deuterium-tritium fuel is compressed to a high density of 1000 times solid density with tens nano-second laser pulses from a compression laser and the compressed fuel core is directly heated to 5 keV with a ten pico-second laser pulse from a heating laser. This FI scheme enables us to design an IFE power plant with a 1MJ-class, compact laser whose output energy is 1/4 of previous central ignition scheme. Recent progress on cooled Yb-YAG ceramic laser revealed that highly efficient compression and heating lasers can be constructed using this laser material with acceptable construction cost including laser diodes for pumping and the refrigerator. New reactor scheme for a liquid wall reactor that has no stagnation point of ablated gas and a rotary shutter system to protect the final optics are proposed. Current computer simulation indicates thermonuclear gain of 160 will be achieved with 1.1 MJ / 10 ns compression lasers and a 100 kJ/10 ps heating laser. A diode-pumped, cooled, Yb-YAG ceramic-laser is the prior candidate for the compression laser operated at 16 Hz rep rate. The conversion efficiencies from electricity to laser are 9.5% for the compression laser, 3.5% for the heating laser, and 6.9% in total including cooling power, respectively. The power plant consists of 4 module reactors powered by one laser system. One module reactor has 32 compression beams, one heating laser, and two target injectors as shown. Each beam port has a rotary shutter and an electro magnet to prevent the final optics from neutral vapor and ions, respectively. The panels of the first wall are tilted by 30 degree to avoid stagnation of evaporated vapor at the chamber center. The focus position is vertically off set to simplify the protection mechanism of the ceiling. (author)

  11. Carbon footprint of automotive ignition coil

    Science.gov (United States)

    Chang, Huey-Ling; Chen, Chih-Ming; Sun, Chin-Huang; Lin, Hung-Di

    2015-07-01

    In recent years, environmental issues, such as climate change and global warming due to the excessive development of industry, have attracted increasing attention of citizens worldwide. It is known that CO2 accounts for the largest proportion of greenhouse gases. Therefore, how to reduce CO2 emissions during the life cycle of a product to lessen its impact on environment is an important topic in the industrial society. Furthermore, it is also of great significance to cut down the required energy so as to lower its production costs during the manufacturing process nowadays. This study presents the carbon footprint of an automotive ignition coil and its partial materials are defined to explore their carbon emissions and environmental impact. The model IPCC GWP100a calculates potential global greenhouse effect by converting them into CO2 equivalents. In this way, the overall carbon footprint of an ignition coil can be explored. By using IPCC GWP100a, the results display that the shell has the most carbon emissions. The results can help the industry reduce the carbon emissions of an ignition coil product.

  12. Laser spark distribution and ignition system

    Science.gov (United States)

    Woodruff, Steven; McIntyre, Dustin L.

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  13. Ignition threshold for non-Maxwellian plasmas

    Science.gov (United States)

    Hay, Michael J.; Fisch, Nathaniel J.

    2015-11-01

    An optically thin p-11B plasma loses more energy to bremsstrahlung than it gains from fusion reactions, unless the ion temperature can be elevated above the electron temperature. In thermal plasmas, the temperature differences required are possible in small Coulomb logarithm regimes, characterized by high density and low temperature. Ignition could be reached more easily if the fusion reactivity can be improved with nonthermal ion distributions. To establish an upper bound for the potential utility of a nonthermal distribution, we consider a monoenergetic beam with particle energy selected to maximize the beam-thermal reactivity. Comparing deuterium-tritium (DT) and p-11B, the minimum Lawson criteria and minimum ρR required for inertial confinement fusion (ICF) volume ignition are calculated with and without the nonthermal feature. It turns out that channeling fusion alpha energy to maintain such a beam facilitates ignition at lower densities and ρR, improves reactivity at constant pressure, and could be used to remove helium ash. On the other hand, the reactivity gains that could be realized in DT plasmas are significant, the excess electron density in p-11B plasmas increases the recirculated power cost to maintain a nonthermal feature and thereby constrains its utility to ash removal.

  14. Ignition threshold for non-Maxwellian plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Hay, Michael J., E-mail: hay@princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Fisch, Nathaniel J. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2015-11-15

    An optically thin p-{sup 11}B plasma loses more energy to bremsstrahlung than it gains from fusion reactions, unless the ion temperature can be elevated above the electron temperature. In thermal plasmas, the temperature differences required are possible in small Coulomb logarithm regimes, characterized by high density and low temperature. Ignition could be reached more easily if the fusion reactivity can be improved with nonthermal ion distributions. To establish an upper bound for the potential utility of a nonthermal distribution, we consider a monoenergetic beam with particle energy selected to maximize the beam-thermal reactivity. Comparing deuterium-tritium (DT) and p-{sup 11}B, the minimum Lawson criteria and minimum ρR required for inertial confinement fusion (ICF) volume ignition are calculated with and without the nonthermal feature. It turns out that channeling fusion alpha energy to maintain such a beam facilitates ignition at lower densities and ρR, improves reactivity at constant pressure, and could be used to remove helium ash. On the other hand, the reactivity gains that could be realized in DT plasmas are significant, the excess electron density in p-{sup 11}B plasmas increases the recirculated power cost to maintain a nonthermal feature and thereby constrains its utility to ash removal.

  15. Ignition threshold for non-Maxwellian plasmas

    International Nuclear Information System (INIS)

    An optically thin p-11B plasma loses more energy to bremsstrahlung than it gains from fusion reactions, unless the ion temperature can be elevated above the electron temperature. In thermal plasmas, the temperature differences required are possible in small Coulomb logarithm regimes, characterized by high density and low temperature. Ignition could be reached more easily if the fusion reactivity can be improved with nonthermal ion distributions. To establish an upper bound for the potential utility of a nonthermal distribution, we consider a monoenergetic beam with particle energy selected to maximize the beam-thermal reactivity. Comparing deuterium-tritium (DT) and p-11B, the minimum Lawson criteria and minimum ρR required for inertial confinement fusion (ICF) volume ignition are calculated with and without the nonthermal feature. It turns out that channeling fusion alpha energy to maintain such a beam facilitates ignition at lower densities and ρR, improves reactivity at constant pressure, and could be used to remove helium ash. On the other hand, the reactivity gains that could be realized in DT plasmas are significant, the excess electron density in p-11B plasmas increases the recirculated power cost to maintain a nonthermal feature and thereby constrains its utility to ash removal

  16. Smart semiconductor bridge (SCB) igniter for explosives

    Science.gov (United States)

    Bickes, R. W., Jr.

    We have developed a silicon semiconductor bridge (SCB) igniter which, when driven with a low-energy current pulse, produces a plasma discharge that ignites explosive materials pressed against the bridge. Our experiments have demonstrated that SCB explosive devices function in a few tens of microseconds at one-tenth the input energy of hot-wire devices. Despite the low input energies for ignition, tests have revealed SCB devices to be explosively safe, passing electrostatic discharge (ESD) requirements and no-fire current levels. In fact, SCB devices have better no-fire characteristics than hot-wire devices, because of the intimate bridge contact with the underlying thermally conductive substrate. We have tested several different prototype explosive devices including pyrotechnic actuators, secondary explosive deflagration-to-detonation detonators and a primary explosive detonator. In addition, we have tested SCB actuators with breadboarded smart firing sets that will fire the SCB actuators only after transmission of a digital code, after a preset delay, or in a preprogrammed sequence. We have also tested an optical system that requires only a single fiber optic cable connecting the SCB device to a low power laser that both energizes the firing set and transmits a coded firing signal.

  17. Diagnostics for fast ignition science (invited).

    Science.gov (United States)

    MacPhee, A G; Akli, K U; Beg, F N; Chen, C D; Chen, H; Clarke, R; Hey, D S; Freeman, R R; Kemp, A J; Key, M H; King, J A; Le Pape, S; Link, A; Ma, T Y; Nakamura, H; Offermann, D T; Ovchinnikov, V M; Patel, P K; Phillips, T W; Stephens, R B; Town, R; Tsui, Y Y; Wei, M S; Van Woerkom, L D; Mackinnon, A J

    2008-10-01

    The ignition concept for electron fast ignition inertial confinement fusion requires sufficient energy be transferred from an approximately 20 ps laser pulse to the compressed fuel via approximately MeV electrons. We have assembled a suite of diagnostics to characterize such transfer, simultaneously fielding absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256 eV; spherically bent crystal imagers at 4.5 and 8 keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung, electron and proton spectrometers (along the same line of sight), and a picosecond optical probe interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following the laser-plasma interactions at extremely high intensities in both planar and conical targets. Together with accurate on-shot laser focal spot and prepulse characterization, these measurements are yielding new insights into energy coupling and are providing critical data for validating numerical particle-in-cell (PIC) and hybrid PIC simulation codes in an area crucial for fast ignition and other applications. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultrahigh intensity laser-plasma interactions are discussed. PMID:19044615

  18. Nd:YAG breech mounted laser igniter

    Science.gov (United States)

    Hardy, Christopher R.; Myers, Michael J.; Myers, John D.; Gadson, Robert L.; Leone, Joseph; Fay, Josiah W.; Boyd, Kevin

    2005-09-01

    Nd:YAG lasers have been successfully used to demonstrate laser ignition of howitzer propellant charges including bag, stick, and the Modular Artillery Charge System (MACS). Breech Mount Laser Ignition Systems (BMLIS) have been designed, installed and tested on many artillery systems, including the US Army's M109A6 Paladin, M198, M777 Light Weight, Crusader, and Non-Line-of-Sight Cannon (NLOS-C). The NLOS-C incorporates advanced weapon technologies, to include a BMLIS. United Defense's Armament Systems Division has recently designed and built a NLOS-C System Demonstrator that uses a BMLIS that incorporates Kigre's patented square pulse technology. NLOS-C is one of the weapon systems being developed for use with the US Army's "systems of systems" Future Combat System (FCS), Manned Ground Vehicles (MGV) program, and is currently undergoing development testing at Yuma Proving Grounds. In this paper we discuss many technical aspects of an artillery laser ignition system and present BMLIS test data obtained from actual gun firings conducted with a number of different US Army howitzer platforms.

  19. Innovative ICF scheme-impact fast ignition

    International Nuclear Information System (INIS)

    A totally new ignition scheme for ICF, impact fast ignition (IFI), is proposed [1], in which the compressed DT main fuel is to be ignited by impact collision of another fraction of separately imploded DT fuel, which is accelerated in the hollow conical target. Two-dimensional hydrodynamic simulation results in full geometry are presented, in which some key physical parameters for the impact shell dynamics such as 108 cm/s of the implosion velocity, 200- 300 g/cm3 of the compressed density, and the converted temperature beyond 5 keV are demonstrated. As the first step toward the proof-of-principle of IFI, we have conducted preliminary experiments under the operation of GEKKO XII/HYPER laser system to achieve a hyper-velocity of the order of 108 cm/s. As a result we have observed a highest velocity, 6.5 x 107 cm/s, ever achieved. Furthermore, we have also done the first integrated experiments using the target and observed substantial amount of neutron yields. Reference: [1] M. Murakami and Nagatomo, Nucl. Instrum. Meth. Phys. Res. A 544(2005) 67

  20. The national ignition facility performance status

    Energy Technology Data Exchange (ETDEWEB)

    Haynam, C.; Auerbach, J.; Bowers, M.; Di-Nicola, J.M.; Dixit, S.; Erbert, G.; Heestand, G.; Henesian, M.; Jancaitis, K.; Manes, K.; Marshall, C.; Mehta, N.; Nostrand, M.; Orth, C.; Sacks, R.; Shaw, M.; Sutton, S.; Wegner, P.; Williams, W.; Widmayer, C.; White, R.; Yang, S.; Van Wonterghem, B. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2006-06-15

    The National Ignition Facility (NIF) laser has been designed to support high energy density science, including the demonstration of fusion ignition through Inertial Confinement. NIF operated a single 'quad' of 4 beams from December 2002 through October 2004 in order to gain laser operations experience, support target experiments, and demonstrate laser performance consistent with NIF's design requirement. During this two-year period, over 400 Main Laser shots were delivered at 1{omega} to calorimeters for diagnostic calibration purposes, at 3{omega} to the Target Chamber, and at 1{omega}, 2{omega}, and 3{omega} to the precision diagnostic system (PDS). The PDS includes its own independent single beam transport system, NIF design frequency conversion hardware and optics, and laser sampling optics that deliver light to a broad range of laser diagnostics. Highlights of NIF laser performance will be discussed including the results of high energy 2{omega} and 3{omega} experiments, the use of multiple focal spot beam conditioning techniques, the reproducibility of laser performance on multiple shots, the generation on a single beam of a 3{omega} temporally shaped ignition pulse at full energy and power, and recent results on full bundle (8 beamline) performance. NIF's first quad laser performance meets or exceeds NIF's design requirements. (authors)

  1. The National Ignition Facility Performance Status

    Energy Technology Data Exchange (ETDEWEB)

    Haynam, C; Auerbach, J; Nicola, J D; Dixit, S; Heestand, G; Henesian, M; Jancaitis, K; Manes, K; Marshall, C; Mehta, N; Nostrand, M; Orth, C; Sacks, R; Shaw, M; Sutton, S; Wegner, P; Williams, W; Widmayer, C; White, R; Yang, S; Van Wonterghem, B

    2005-08-30

    The National Ignition Facility (NIF) laser has been designed to support high energy density science (HEDS), including the demonstration of fusion ignition through Inertial Confinement. NIF operated a single ''quad'' of 4 beams from December 2002 through October 2004 in order to gain laser operations experience, support target experiments, and demonstrate laser performance consistent with NIF's design requirement. During this two-year period, over 400 Main Laser shots were delivered at 1{omega} to calorimeters for diagnostic calibration purposes, at 3{omega} to the Target Chamber, and at 1{omega}, 2{omega}, and 3{omega} to the Precision Diagnostics System (PDS). The PDS includes its own independent single beam transport system, NIF design frequency conversion hardware and optics, and laser sampling optics that deliver light to a broad range of laser diagnostics. Highlights of NIF laser performance will be discussed including the results of high energy 2{omega} and 3{omega} experiments, the use of multiple focal spot beam conditioning techniques, the reproducibility of laser performance on multiple shots, the generation on a single beam of a 3{omega} temporally shaped ignition pulse at full energy and power, and recent results on full bundle (8 beamline) performance. NIF's first quad laser performance meets or exceeds NIF's design requirements.

  2. Fabrication and Characterization of Fast Ignition Targets

    International Nuclear Information System (INIS)

    Fast ignition is a novel scheme for achieving laser fusion. A class of these targets involves cone mounted CH shells. We have been fabricating such targets with shells with a wide variety of diameters and wall thicknesses for several years at General Atomics. In addition, recently such shells were needed for implosion experiments at Laboratory for Laser Energetics (LLE) that for the first time were required to be gas retentive. Fabrication of these targets requires producing appropriate cones and shells, assembling the targets, and characterization of the assembled targets. The cones are produced using micromachining and plating techniques. The shells are fabricated using the depolymerizable mandrel technique followed by micromachining a hole for the cone. The cone and the shell then need to be assembled properly for gas retention and precisely in order to position the cone tip at the desired position within the shell. Both are critical for the fast ignition experiments. The presence of the cone in the shell creates new challenges in characterization of the assembled targets. Finally, for targets requiring a gas fill, the cone-shell assembly needs to be tested for gas retention and proper strength at the glue joint. This paper presents an overview of the developmental efforts and technical issues addressed during the fabrication of fast ignition targets

  3. FABRICATION AND CHARACTERIZATION OF FAST IGNITION TARGETS

    International Nuclear Information System (INIS)

    OAK-B135 Fast ignition is a novel scheme for achieving laser fusion. A class of these targets involves cone mounted CH shells. The authors have been fabricating such targets with shells with a wide variety of diameters and wall thicknesses for several years at General Atomics. In addition, recently such shells were needed for implosion experiments at Laboratory for Laser Energetics (LLE) that for the first time were required to be gas retentive. Fabrication of these targets requires producing appropriate cones and shells, assembling the targets, and characterization of the assembled targets. The cones are produced using micromachining and plating techniques. The shells are fabricated using the depolymerizable mandrel technique followed by micromachining a hole for the cone. The cone and the shell then need to be assembled properly for gas retention and precisely in order to position the cone tip at the desired position within the shell. Both are critical for the fast ignition experiments. The presence of the cone in the shell creates new challenges in characterization of the assembled targets. Finally, for targets requiring a gas fill, the cone-shell assembly needs to be tested for gas retention and proper strength at the glue joint. This paper presents an overview of the developmental efforts and technical issues addressed during the fabrication of fast ignition targets

  4. Overview of the National Ignition Facility

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory will be the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. NIF is a 192 beam Nd-glass laser facility that will produce 1.8 MJ, 500 TW of ultraviolet light making it over fifty times more energetic than present ICF facilities. The NIF Project began in 1995 and is scheduled for completion in 2009. Ignition experiments on NIF, which will use tritium, are scheduled to begin in 2010. Tritium will arrive at the facility in individual target assemblies. The assemblies will be mounted to the Cryogenic TARget POSitioner (TARPOS), which provides the cryogenic cooling systems necessary to complete the formation of the ignition target's fuel ice layer. It also provides the positioning system that transports and holds the target at the center of the NIF chamber during a shot. After a shot, unburned tritium will be captured by the cryopumps. Upon regeneration, the cryopump effluent will be directed to the Tritium Processing System, part of NIF's. Personnel and Environmental Protection Systems. These systems also include, local contamination control systems, area and stack tritium monitoring systems, a decontamination area, and waste packaging and characterization capability. This equipment will be used along with standard contamination control practices to manage the tritium hazard to workers and to limit releases to the environment to negligibly small amounts

  5. The significance of 18F-FP-β-CIT dopamine transporter PET imaging in early diagnosis of Parkinson's disease

    International Nuclear Information System (INIS)

    Objective: To evaluate the 18 F-N-3-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane (18F-FP-β-CIT) dopamine transporter (DAT) PET imaging in diagnosing Parkinson's disease with early stage and assessing the severity of their disability. Methods: 4 healthy controls, 21 parkinsonian patients with early stage and 10 parkinsonian patients with advanced stage were studied, the ratio of [ region of interest (ROI)-cerebellum]/cerebellum was measured and compared. The correlation between DAT binding in striatum and unified Parkinson's disease rating scale (UPDRS) motor scores was also determined. Results: In patients with early stage (Hoehn and Yahr stage I-II) , the DAT binding uptake in the caudate, anterior putamen and posterior putamen was significantly reduced to 71.8%, 43.8% and 23.6% of the control value respectively, and more pronounced reduction of the uptake was found in the striatum contralateral to the predominant symptoms. Compared with age-matched controls, there was a significant reduction of DAT binding in the ipsilateral (preclinical) striatum of hemi-parkinsonian patients with Hoehn and Yahr stage 1 or 1.5. In the patients with advanced stage, the corresponding figure were further reduced to 51.9%, 31.8%, 15.8%. The DAT binding uptake in striatum of all parkinsonian patients showed significantly negative correlation with UPDRS motor scores, especially in the subregion of posterior putamen. Conclusion: 18F-FP-β-CIT DAT PET imaging is helpful in diagnosing Parkinson's disease with early stage and assessing the severity of their disability

  6. Shock ignition: a new approach to high gain inertial confinement fusion on the national ignition facility.

    Science.gov (United States)

    Perkins, L J; Betti, R; LaFortune, K N; Williams, W H

    2009-07-24

    Shock ignition, an alternative concept for igniting thermonuclear fuel, is explored as a new approach to high gain, inertial confinement fusion targets for the National Ignition Facility (NIF). Results indicate thermonuclear yields of approximately 120-250 MJ may be possible with laser drive energies of 1-1.6 MJ, while gains of approximately 50 may still be achievable at only approximately 0.2 MJ drive energy. The scaling of NIF energy gain with laser energy is found to be G approximately 126E (MJ);{0.510}. This offers the potential for high-gain targets that may lead to smaller, more economic fusion power reactors and a cheaper fusion energy development path. PMID:19659364

  7. Modeling Ignition and Combustion in Direct Injection Compression Ignition Engines Employing Very Early Injection Timing

    Science.gov (United States)

    Miyamoto, Takeshi; Tsurushima, Tadashi; Shimazaki, Naoki; Harada, Akira; Sasaki, Satoru; Hayashi, Koichi; Asaumi, Yasuo; Aoyagi, Yuzo

    An ignition and combustion model has been developed to predict the heat release rate in direct injection compression ignition engines employing very early injection timing. The model describes the chemical reactions, including low-temperature oxidation. The KIVA II computer code was modified with the present ignition and combustion model. The numerical results indicate that the model developed in this work reproduces major features of two-stage autoignition, as well as experimentally observed trends in NOx and unburned fuel emissions. The computational results show that fuel injection timing significantly influences NOx emissions. Results also indicate that fuel droplets that enter the squish region possibly become unburned fuel emissions. Some graphical results demonstrate the relationships among the in-cylinder fuel spray distributions, fuel-air equivalence ratio, temperature, and mass fractions of NO and unburned fuel.

  8. Self-Propagating Reactive Fronts in Compacts of Multilayered Particles

    International Nuclear Information System (INIS)

    Reactive multilayered foils in the form of thin films have gained interest in various applications such as joining, welding, and ignition. Typically, thin film multilayers support self-propagating reaction fronts with speeds ranging from 1 to 20 m/s. In some applications, however, reaction fronts with much smaller velocities are required. This recently motivated Fritz et al. (2011) to fabricate compacts of regular sized/shaped multilayered particles and demonstrate self-sustained reaction fronts having much smaller velocities than thin films with similar layering. In this work, we develop a simplified numerical model to simulate the self-propagation of reactive fronts in an idealized compact, comprising identical Ni/Al multilayered particles in thermal contact. The evolution of the reaction in the compact is simulated using a two-dimensional transient model, based on a reduced description of mixing, heat release, and thermal transport. Computed results reveal that an advancing reaction front can be substantially delayed as it crosses from one particle to a neighboring particle, which results in a reduced mean propagation velocity. A quantitative analysis is thus conducted on the dependence of these phenomena on the contact area between the particles, the thermal contact resistance, and the arrangement of the multilayered particles.

  9. Compaction properties of agricultural soils

    OpenAIRE

    TANG, Anh Minh; CUI, Yu Jun; Eslami, Javad; DEFOSSEZ BERTHOUD, Pauline

    2007-01-01

    The compaction of field soils due to repeated rolling of agricultural vehicles is one of the main reasons for the agricultural soil degradation. A good understanding of the compaction properties of these soils is essential for an optimum organisation of agricultural activities, and therefore for environmental protection in terms of nitrate migrations. In the present work, the compaction properties of agricultural soils from four sites in France are studied after experimental data ...

  10. Soil compaction in forest soils

    OpenAIRE

    TURGUT, Bülent

    2012-01-01

    Soil compaction is a widespread degradation process in forest sites. Soil degradation occurring on the structural formation of a natural soil system by rainfall or mechanical outer forces generally results in soil particles to be rearranged tighter than its previous status. In this case, soil compaction -defined as the increase in bulk density of soil- develops with negative effects on soil-plant-water relations. With the compaction, the density of soil increases while the porosity rate decre...

  11. Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs

    International Nuclear Information System (INIS)

    Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and, most recently, experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as 2000, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to 200 on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode 1200 have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

  12. High resolution simulations of ignition capsule designs for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D S; Haan, S W; Cook, A W; Edwards, M J; Hammel, B A; Koning, J M; Marinak, M M

    2011-02-17

    Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and - most recently - experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as two thousand, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to two hundred on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode twelve hundred have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

  13. Heat wave fast ignition in inertial confinement energy

    Institute of Scientific and Technical Information of China (English)

    Shalom; Eliezer; Shirly; Vinikman; Pinhasi

    2013-01-01

    An accelerated micro-foil is used to ignite a pre-compressed cylindrical shell containing deuterium–tritium fuel.The well-known shock wave ignition criterion and a novel criterion based on heat wave ignition are developed in this work.It is shown that for heat ignition very high impact velocities are required.It is suggested that a multi-petawatt laser can accelerate a micro-foil to relativistic velocities in a very short time duration(picosecond)of the laser pulse.The cylindrical geometry suggested here for the fast ignition approach has the advantage of geometrically separating the nanosecond lasers that compress the target from the picosecond laser that accelerates the foil.The present model suggests that nuclear fusion by micro-foil impact ignition could be attained with currently existing technology.

  14. Capsule performance optimization in the National Ignition Campaign

    International Nuclear Information System (INIS)

    A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

  15. Capsule performance optimization in the National Ignition Campaigna)

    Science.gov (United States)

    Landen, O. L.; Boehly, T. R.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Hoffman, N.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Kyrala, G. A.; Michel, P.; Milovich, J.; Munro, D. H.; Nikroo, A.; Olson, R. E.; Robey, H. F.; Spears, B. K.; Thomas, C. A.; Weber, S. V.; Wilson, D. C.; Marinak, M. M.; Suter, L. J.; Hammel, B. A.; Meyerhofer, D. D.; Atherton, J.; Edwards, J.; Haan, S. W.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.

    2010-05-01

    A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

  16. Capsule performance optimization in the national ignition campaign

    International Nuclear Information System (INIS)

    A capsule performance optimization campaign will be conducted at the National Ignition Facility [1] to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

  17. Capsule performance optimization in the national ignition campaign

    Science.gov (United States)

    Landen, O. L.; MacGowan, B. J.; Haan, S. W.; Edwards, J.

    2010-08-01

    A capsule performance optimization campaign will be conducted at the National Ignition Facility [1] to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

  18. Capsule Performance Optimization in the National Ignition Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Landen, O L; MacGowan, B J; Haan, S W; Edwards, J

    2009-10-13

    A capsule performance optimization campaign will be conducted at the National Ignition Facility to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

  19. Advances in compact torus research

    International Nuclear Information System (INIS)

    A compact torus is a low aspect ratio, axisymmetric, closed magnetic field line configuration with no vessel wall or magnetic field coils linking the hole in the plasma toroid. This concept offers reactor advantages such as simplicity, high β, and the possibility of translation. Several methods have been used to generate compact toroids, including plasma guns, high energy particle rings, and field-reversed theta pinches. This document summarizes the results of recent work on compact toroids, presented at the first IAEA Technical Committee Meeting on Compact Torus Research held in Sydney, Australia from 4 to 7 March 1985

  20. Ignition on the national ignition facility: A path towards inertial fusion energy

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of ultraviolet light. The NIF Project is scheduled for completion in March 2009. Currently, 136 of the 192 beams have been commissioned, producing over 2.88 MJ of 1ω light and making NIF the world's first megajoule laser. The plan is to begin 96-beam symmetric indirect-drive experiments early next year. These first ICF experiments represent the beginning of NIF experiments for the National Ignition Campaign (NIC). This national effort for ignition experiments is coordinated through a detailed plan that includes the science, technology, and equipment such as diagnostics, cryogenic target manipulator, and user optics required for ignition experiments. Participants in this effort include General Atomics, LLNL, Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion to begin ignition experiments in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. The focus of this talk will be on NIF technical capabilities, the National Ignition Campaign, and challenges for inertial fusion energy. In particular, the talk will address the scientific and technical accomplishments for NIC, the roles and responsibilities of the various partners comprising this national effort, as well as the NIC experimental plans. Successful demonstration of ignition and net energy gain on NIF will represent the first step towards demonstrating the

  1. Characteristics of lightning related to wildfire ignitions in Catalonia

    OpenAIRE

    Pineda Ruegg, Nicolau; Montañá Puig, Juan; Van der Velde, Oscar Arnoud

    2012-01-01

    What are the characteristics of lightning that influence the probability that an individual stroke will ignite a wildfire? It is generally accepted that long continuing current following some return strokes is the cause of ignition in forest fuels. However, because these low-level currents are not detectable with operative Lightning Location Systems, other lightning characteristics correlating with its occurrence have been proposed and used to estimate ignition probability. These ...

  2. Observation of microwave volume plasma ignition in ambient air

    International Nuclear Information System (INIS)

    A pulsed microwave (MW) plasma was maintained in a waveguide with an ignition pin. Images of the MW discharge were recorded during ignition in ambient air with millisecond time resolution and correlated with measurements of absorbed MW power. This work is focused on the quantification of ignition stability and observation of the plasma structure. Additionally, a time- and space-integrated emission spectrum in the range 220–770 nm is presented. (paper)

  3. Experimental Study Of Minimum Ignition Temperature Of Spent Coffee Grounds

    OpenAIRE

    Igor Wachter; Karol Balog; Hana Kobetičová; Aleš Ház

    2016-01-01

    The aim of this scientific paper is an analysis of the minimum ignition temperature of dust layer and the minimum ignition temperatures of dust clouds. It could be used to identify the threats in industrial production and civil engineering, on which a layer of combustible dust could occure. Research was performed on spent coffee grounds. Tests were performed according to EN 50281-2-1:2002 Methods for determining the minimum ignition temperatures of dust (Method A). Objective of method A is to...

  4. Compact acoustic refrigerator

    Science.gov (United States)

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  5. Compact SPS - Power delivery

    Science.gov (United States)

    Pospisil, M.; Pospisilova, L.

    1982-09-01

    The power deliverable by a compact solar Space Power Station (SPS) is a function of its outer surface shape. Methods of fitting the power delivery curve of such a system to different patterns of daily power demand are considered that involve the appropriate choice of the number of satellites, their maximal power, height to width ratio and the shift of longitude with respect to the receiving station. Changes in the daily delivery curve can be made by altering the longitudes and orientations of the satellites. Certain limitations to the choice of parameters exist, such as: the height to width ratio should be near 1.2, and the sum of longitude and orientation changes will probably not be greater than 50 deg. The optimization of the peak to average power ratio is also discussed.

  6. Atacama Compact Array Antennas

    CERN Document Server

    Saito, Masao; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.

  7. Compact pentaquark structures

    CERN Document Server

    Santopinto, Elena

    2016-01-01

    We study the possibility that at least one of the two pentaquark structures recently reported by LHCb can be described as a compact pentaquark state, and we give predictions for new channels that can be studied by the experimentalists if this hypothesis is correct. We use very general arguments dictated by symmetry considerations, in order to describe the pentaquark states within a group theory approach. A complete classification of all possible states and quantum numbers, that can be useful both to the experimentalists, for new finding, or to theoretical model builders, are given, without the introduction of any particular dynamical model. Some prediction are finally given using a Guersey-Radicati inspired mass formula. We reproduce the mass and the quantum numbers of the lightest pentaquark state reported by LHCb ( 3/2^-), with a parameter free mass formula, fixed on the well established baryons. We predict others pentaquark resonances (giving their masses, and suggesting possible decay channels) which belo...

  8. Compact cryocooler heat exchangers

    International Nuclear Information System (INIS)

    Compact heat exchangers are subject to different constraints as a room temperature gas is cooled down by a cold stream returning from a JT valve (or a similar cryoprocess component). In particular, the optimization of exchangers for liquid helium systems has to cover a wide range in temperature and density of the fluid. In the present work we address the following thermodynamic questions: 1. The optimization of intermediate temperatures which optimize stage operation (a stage is assumed to have a constant cross section); 2. The optimum temperature difference available for best overall economic performance values. The results are viewed in the context of porous media concepts applied to rather low speeds of fluid flow in narrow passages. In this paper examples of fluid/solid constraints imposed in this non-classical low temperature area are presented

  9. Compact semiconductor lasers

    CERN Document Server

    Yu, Siyuan; Lourtioz, Jean-Michel

    2014-01-01

    This book brings together in a single volume a unique contribution by the top experts around the world in the field of compact semiconductor lasers to provide a comprehensive description and analysis of the current status as well as future directions in the field of micro- and nano-scale semiconductor lasers. It is organized according to the various forms of micro- or nano-laser cavity configurations with each chapter discussing key technical issues, including semiconductor carrier recombination processes and optical gain dynamics, photonic confinement behavior and output coupling mechanisms, carrier transport considerations relevant to the injection process, and emission mode control. Required reading for those working in and researching the area of semiconductors lasers and micro-electronics.

  10. Compact cosmic objects

    International Nuclear Information System (INIS)

    The data are discussed obtained using the method of superfar radiointerferometry. High angular resolution of radiointerferometers with superlong bases has made compact radiosources placed inside and beyond the Galaxy accessable for investigations. Outer galactic objects with extraordinarily active nuclei have been found. Seyfert galaxies 3C84(NGC 1275) in the Perseus constellation and 3C 345 quasar in the Hercules constellation are objects with active nuclei. In the nuclei of separate quasars extraordinarily active processes take place which are accompanied by outflow of clouds of relativistic particles. The velocity of these particles exceeds the light velocity. Measurements with high angular resolution performed in the shortest wave of the centimeter range (1.35 cm) have permitted to find the double nucleus in the Seyfert galaxy NGC 1275. The superfar radiointerferometry has made interesting discoveries when studying gas-dust galactic nebular. Laser sources that emit bright and narrow lines of hydroxyl and water vapour are found in them

  11. PET imaging of dopamine transporters in the human brain in health and Parkinson's disease with [F-18]β-CIT-FP

    International Nuclear Information System (INIS)

    The N-fluoropropyl analog of β-CIT (2β-carbomethoxy-3β-(4-iodophenyl) tropane], β-CIT-FP, has been labeled with F-18 and shown to bind to the dopamine (DA) transporters with faster kinetics in nonhuman primate brain (Lundkvist et al., 1996). We report the successful application of [F-18]β-CIT-FP to image Da transporters in the living human brain in health and Parkinson's disease (PD). [F-18]β-CIT-FP was prepared by N-alkylation of nor-β-CIT (2 mg) with 1-bromo-3[F-18]fluoropropane (2 drops of DMF/CH3CN, 140 .deg. C, 15 min). 1-Bromo-3-[F-18]fluoropropane was readily obtained in 55-70% yield from a reaction of 3-bromopropyl triflate with [F-18]fluoride (TFH, 90 .deg. C, 2 min). Three healthy subjects and three PD patients were injected i.v. with [F-18]β-CIT-FP and 27 sequential PET images were acquired for 120 min. The tracer demonstrated high brain uptake (10% of the injected dose at 9 min postinjection). Brain activity was highly concentrated in the striatal area. In the healthy subjects, striatal activity peaked within 30 min and remained at similar levels for the rest of the study, with a mean specific (putamen or caudate-cerebellum)-to-nonspecific (cerebellum) binding ratio of 6.7 (putamen) or 7.0 (caudate) at equilibrium. The activity in the thalamus, a region known to contain a high density of serotonin transporters, showed an earlier peak at approximately 15 min and a rapid washout thereafter. The mean (thalamus-cerebellum)/cerebellum ratio at peak thalamic specific binding was 0.9. Frontal and cerebella activity showed similar patterns, exhibiting an early peak within 10 min and rapid washout, followed by stable levels between 80 min and 120 min postinjection. In the PD patients, striatal activity peaked earlier (within 15 min) at reduced levels compared to the healthy subjects, followed by a significant washout. A greater reduction in uptake occurred in the putamen than in the caudate, with lateralized differences in striatal uptake. The mean

  12. [The choice of work clothes and the risk of ignition].

    Science.gov (United States)

    Larsen, T K; Ebbehøj, J

    1989-12-11

    Cotton is easily ignited in atmospheric air. Aramid (Nomex) is only ignited if the oxygen concentration is 30% and the ignition temperature is 800 degrees C. Thirty one steelmill employees used one hundred and twenty suits of working clothes made of cotton, cotton/polyamide, cotton/polyester or Aramid (Nomex) in a four month period. 17% were more comfortable when using cotton/polyester. No differences were found between cotton and Aramid. Cotton should not be used as textile for working clothes in environments with risks of ignition. PMID:2609447

  13. Bulkhead chamber ignition for internal combustion engines. Schottkammerzuendung fuer Verbrennungsmotore

    Energy Technology Data Exchange (ETDEWEB)

    Fox, G.

    1990-12-06

    Bulkhead chamber ignition makes for reliable ignition of different fuels (e.g. petrol or diesel) in internal combustion engines (multifuel engine) that can be operated with an extremely lean fuel-air mixture. This is realized by an open chamber (referred to as bulkhead chamber in the following) inside the combustion chamber which diverts a fraction of the compressed fuel-air mixture from the combustion chamber. After this the pressure in the bulkhead chamber is increased until the mixture ignites spontaneously. The combustion pressure drives back the piston and opens the bulkhead chamber. Then the compressed fuel-air mixture in the combustion chamber is ignited by the released combustion gas.

  14. EFFICIENCY ANALYSIS OF GAS ENGINES MONOSPARK AND MULTISPARK IGNITION SYSTEMS

    Directory of Open Access Journals (Sweden)

    F. Abramchuk

    2014-02-01

    Full Text Available The results of comparison analysis of gas engine monospark and multispark ignition systems indices are presented. The results of these systems experimental investigation are given.

  15. An assessment of two off-shore igniter concepts

    International Nuclear Information System (INIS)

    On June 12, 1996, two controlled in-situ oil spill burns (ISB), using a response-prepared ISB system, were conducted in the North Sea, 40 miles off the U. K. coast. The first burn involved fresh crude oil and was ignited with a hand-held igniter using a standard gelled fuel mixture. In the second burn an emulsified crude was used, ignited with a prototype emulsion breaking igniter (EBI) deployed using the Helitorch. The objective was to determine operational practicalities under realistic conditions when responding to a weathered oil situation in an offshore location. This paper is devoted to an assessment of the two igniter systems used during the trials. Results showed that oil aged by 12 hours with a 25 per cent water content burned down to a three-to-four per cent residue. The fire burn survived the two burns intact. The hand-held ignition system worked with fresh oil and the Helitorch lit emulsified oil using EBI. These trials were the first time that the EBI was deployed from a Helitorch slung beneath a helicopter. It was concluded that (1) the simplicity of the logistics required for the hand-held igniter would favour its use over the Helitorch method for fresh or lightly weathered oil, (2) more heavily weathered oils would require the use of an emulsion-breaking type igniter, and (3) aerial deployment of igniters offer the advantage of allowing more accurate positioning. 10 refs.,5 tabs., 3 figs

  16. Thermal-Catalytic Ignition Source for Ionic Liquid Monopropellants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultramet recently demonstrated rapid, reliable, and repeated ignition of hydroxylammonium nitrate (HAN)-hydroxyethylhydrazinium nitrate (HEHN) monopropellant...

  17. Highly Durable Catalysts for Ignition of Advanced Monopropellants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed SBIR Phase I addresses the development of catalysts and technology for the ignition of advanced monopropellants consisting of mixtures of...

  18. Status and Prospects of the Fast Ignition Inertial Fusion Concept

    Energy Technology Data Exchange (ETDEWEB)

    Key, M H

    2006-11-15

    Fast ignition is an alternate concept in inertial confinement fusion, which has the potential for easier ignition and greater energy multiplication. If realized it could improve the prospects for inertial fusion energy. It poses stimulating challenges in science and technology and the research is approaching a key stage in which the feasibility of fast ignition will be determined. This review covers the concepts, the state of the science and technology, the near term prospects and the challenges and risks involved in demonstrating high gain fast ignition.

  19. Review of the National Ignition Campaign 2009-2012

    International Nuclear Information System (INIS)

    The National Ignition Campaign (NIC) was a multi-institution effort established under the National Nuclear Security Administration of DOE in 2005, prior to the completion of the National Ignition Facility (NIF) in 2009. The scope of the NIC was the planning and preparation for and the execution of the first 3 yr of ignition experiments (through the end of September 2012) as well as the development, fielding, qualification, and integration of the wide range of capabilities required for ignition. Besides the operation and optimization of the use of NIF, these capabilities included over 50 optical, x-ray, and nuclear diagnostic systems, target fabrication facilities, experimental platforms, and a wide range of NIF facility infrastructure. The goal of ignition experiments on the NIF is to achieve, for the first time, ignition and thermonuclear burn in the laboratory via inertial confinement fusion and to develop a platform for ignition and high energy density applications on the NIF. The goal of the NIC was to develop and integrate all of the capabilities required for a precision ignition campaign and, if possible, to demonstrate ignition and gain by the end of FY12. The goal of achieving ignition can be divided into three main challenges. The first challenge is defining specifications for the target, laser, and diagnostics with the understanding that not all ignition physics is fully understood and not all material properties are known. The second challenge is designing experiments to systematically remove these uncertainties. The third challenge is translating these experimental results into metrics designed to determine how well the experimental implosions have performed relative to expectations and requirements and to advance those metrics toward the conditions required for ignition. This paper summarizes the approach taken to address these challenges, along with the progress achieved to date and the challenges that remain. At project completion in 2009, NIF lacked

  20. Mars in situ propellants: Carbon monoxide and oxygen ignition experiments

    Science.gov (United States)

    Linne, Diane L.; Roncace, James; Groth, Mary F.

    1990-01-01

    Carbon monoxide and oxygen were tested in a standard spark-torch igniter to identify the ignition characteristics of this potential Mars in situ propellant combination. The ignition profiles were determined as functions of mixture ratio, amount of hydrogen added to the carbon monoxide, and oxygen inlet temperature. The experiments indicated that the carbon monoxide and oxygen combination must have small amounts of hydrogen present to initiate reaction. Once the reaction was started, the combustion continued without the presence of hydrogen. A mixture ratio range was identified where ignition occurred, and this range varied with the oxygen inlet temperature.

  1. Fast ignition physics and its requirements to numerical simulation

    International Nuclear Information System (INIS)

    Fast ignition is a new igniting scheme for inertial confinement fusion (ICF). However, the theoretical and experimental researches show that the ignition phase of the fast ignition is very complicated and difficult. The fast ignition research needs a deep and thorough numerical simulation. Based on physical analysis, the requirements of the fast ignition for the numerical simulation are explored, and, at the same time, the problem in the light of the specific conditions of our institute is discussed. The fast ignition mainly includes three processes, those are implosive pre-compression, ultra-intense laser propagation in sub-critical and super-critical plasmas (channeling and boring), and the generation and transportation of hot electrons in plasma, especially in dense plasma, with producing the high-temperature ignition zone. The research considers that for target pre-compression, not only 1D, 2D, but also three-dimensional laser target coupling code are needed; to describe the behavior of hot electron the Fokker-Planck equation considering electric and magnetic fields is suitable, whereas the hydrodynamic motion of the plasma should be two-streaming, with the electrical and magnetic effects included. PIC code could be used to investigate the local details and supply the data needed for solving the mentioned equations. Furthermore, some countries-planed future projects for realizing the fast ignition in a concise way are still stated. (authors)

  2. Quantitation of dopamine transporter blockade by methylphenidate: first in vivo investigation using [{sup 123}I]FP-CIT and a dedicated small animal SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaus, Susanne; Wirrwar, Andreas; Antke, Christina; Arkian, Shahram; Mueller, Hans-Wilhelm; Larisch, Rolf [Heinrich-Heine University, Clinic of Nuclear Medicine, Duesseldorf (Germany); Schramm, Nils [Research Center Juelich, Central Laboratory for Electronics, Juelich (Germany)

    2005-03-01

    The aim of this study was to investigate the feasibility of assessing dopamine transporter binding after treatment with methylphenidate in the rat using a recently developed high-resolution small animal single-photon emission computed tomograph (TierSPECT) and [{sup 123}I]FP-CIT. [{sup 123}I]FP-CIT was administered intravenously 1 h after intraperitoneal injection of methylphenidate (10 mg/kg) or vehicle. Animals underwent scanning 2 h after radioligand administration. The striatum was identified by superimposition of [{sup 123}I]FP-CIT scans with bone metabolism and perfusion scans obtained with {sup 99m}Tc-DPD and {sup 99m}Tc-tetrofosmin, respectively. As these tracers do not pass the blood-brain barrier, their distribution permits the identification of extracerebral anatomical landmarks such as the orbitae and the harderian glands. The cerebellum was identified by superimposing [{sup 123}I]FP-CIT scans with images of brain perfusion obtained with {sup 99m}Tc-HMPAO. Methylphenidate-treated animals and vehicle-treated animals yielded striatal equilibrium ratios (V''{sub 3}) of 0.24{+-}0.26 (mean {+-} SD) and 1.09{+-}0.42, respectively (ttest, two-tailed, p<0.0001). Cortical V''{sub 3} values amounted to 0.05{+-}0.28 (methylphenidate) and 0.3{+-}0.39 (saline, p=0.176). This first in vivo study of rat dopamine transporter binding after pre-treatment with methylphenidate showed a mean reduction of 78% in striatal [{sup 123}I]FP-CIT accumulation. The results can be interpreted in terms of a pharmacological blockade in the rat striatum and show that in vivo quantitation of dopamine transporter binding is feasible with [{sup 123}I]FP-CIT and the TierSPECT. This may be of future relevance for in vivo investigations on rat models of attention deficit/hyperactivity disorder. Furthermore, our findings suggest that investigations in other animal models, e.g. of Parkinson's and Huntington's disease, may be feasible using SPECT radioligands and

  3. Quantitation of dopamine transporter blockade by methylphenidate: first in vivo investigation using [123I]FP-CIT and a dedicated small animal SPECT

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the feasibility of assessing dopamine transporter binding after treatment with methylphenidate in the rat using a recently developed high-resolution small animal single-photon emission computed tomograph (TierSPECT) and [123I]FP-CIT. [123I]FP-CIT was administered intravenously 1 h after intraperitoneal injection of methylphenidate (10 mg/kg) or vehicle. Animals underwent scanning 2 h after radioligand administration. The striatum was identified by superimposition of [123I]FP-CIT scans with bone metabolism and perfusion scans obtained with 99mTc-DPD and 99mTc-tetrofosmin, respectively. As these tracers do not pass the blood-brain barrier, their distribution permits the identification of extracerebral anatomical landmarks such as the orbitae and the harderian glands. The cerebellum was identified by superimposing [123I]FP-CIT scans with images of brain perfusion obtained with 99mTc-HMPAO. Methylphenidate-treated animals and vehicle-treated animals yielded striatal equilibrium ratios (V''3) of 0.24±0.26 (mean ± SD) and 1.09±0.42, respectively (ttest, two-tailed, p''3 values amounted to 0.05±0.28 (methylphenidate) and 0.3±0.39 (saline, p=0.176). This first in vivo study of rat dopamine transporter binding after pre-treatment with methylphenidate showed a mean reduction of 78% in striatal [123I]FP-CIT accumulation. The results can be interpreted in terms of a pharmacological blockade in the rat striatum and show that in vivo quantitation of dopamine transporter binding is feasible with [123I]FP-CIT and the TierSPECT. This may be of future relevance for in vivo investigations on rat models of attention deficit/hyperactivity disorder. Furthermore, our findings suggest that investigations in other animal models, e.g. of Parkinson's and Huntington's disease, may be feasible using SPECT radioligands and small animal imaging systems. (orig.)

  4. The Finslerian compact star model

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, Farook; Paul, Nupur [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); De, S.S. [University of Calcutta, Department of Applied Mathematics, Kolkata (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Jafry, M.A.K. [Shibpur Dinobundhoo Institution, Department of Physics, Howrah, West Bengal (India)

    2015-11-15

    We construct a toy model for compact stars based on the Finslerian structure of spacetime. By assuming a particular mass function, we find an exact solution of the Finsler-Einstein field equations with an anisotropic matter distribution. The solutions are revealed to be physically interesting and pertinent for the explanation of compact stars. (orig.)

  5. A pedagogical history of compactness

    OpenAIRE

    Raman-Sundström, Manya

    2010-01-01

    Compactness is a central notion in advanced mathematics, but we often teach the concept without much historical motivation.  This paper fills in many of the gaps left by the standard textbook treatment, including what motivated the definition, how did the definition evolve, and how can compactness be expressed in terms of nets and filters.

  6. The Meaning of a Compact

    Science.gov (United States)

    Wasescha, Anna

    2016-01-01

    To mark the 30th anniversary of "Campus Compact," leaders from across the network came together in the summer of 2015 to reaffirm a shared commitment to the public purposes of higher education. Campus Compact's 30th Anniversary Action Statement of Presidents and Chancellors is the product of that collective endeavor. In signing the…

  7. Warm compacting behavior of stainless steel powders

    Institute of Scientific and Technical Information of China (English)

    肖志瑜; 柯美元; 陈维平; 召明; 李元元

    2004-01-01

    The warm compacting behaviors of four different kinds of stainless steel powders, 304L, 316L, 410L and 430L, were studied. The results show that warm compaction can be applied to stainless steel powders. The green densities and strengths of compacts obtained through warm compaction are generally higher than those obtained through cold compaction. The compacting behaviors in warm compaction and cold compaction are similar.Under the compacting pressure of 700 MPa, the warm compacted densities are 0. 10 - 0.22 g/cm3 higher than the cold compacted ones, and the green strengths are 11.5 %-50 % higher. The optimal warm compacting temperature is 100 - 110 ℃. In the die wall lubricated warm compaction, the optimum internal lubricant content is 0.2%.

  8. 76 FR 37953 - Standards of Performance for Stationary Compression Ignition and Spark Ignition Internal...

    Science.gov (United States)

    2011-06-28

    ... stationary spark ignition (SI) engines (73 FR 3567). While these regulations are distinct from the standards.... On June 8, 2010 (75 FR 32612), the EPA proposed amendments to the standards of performance for...). The NSPS were originally promulgated on July 11, 2006 (71 FR 39153). New source performance...

  9. 75 FR 32611 - Standards of Performance for Stationary Compression Ignition and Spark Ignition Internal...

    Science.gov (United States)

    2010-06-08

    ... containing separate standards of performance for stationary spark ignition (SI) engines. (73 FR 3567) While... were initially published on July 11, 2006 (71 FR 39153). New source performance standards implement... noted in the proposed rule (70 FR 39870) that it was reviewing the possibility of promulgating...

  10. A trial of ignition innovation of gasoline engine by nanosecond pulsed low temperature plasma ignition

    International Nuclear Information System (INIS)

    Application of nanosecond pulsed low temperature plasma as an ignition technique for automotive gasoline engines, which require a discharge under conditions of high back pressure, has been studied experimentally using a single-cylinder engine. The nanosecond pulsed plasma refers to the transient (non-equilibrated) phase of a plasma before the formation of an arc discharge; it was obtained by applying a high voltage with a nanosecond pulse (FWHM of approximately 80 or 25 ns) between coaxial cylindrical electrodes. It was confirmed that nanosecond pulsed plasma can form a volumetric multi-channel streamer discharge at an energy consumption of 60 mJ cycle-1 under a high back pressure of 1400 kPa. It was found that the initial combustion period was shortened compared with the conventional spark ignition. The initial flame visualization suggested that the nanosecond pulsed plasma ignition results in the formation of a spatially dispersed initial flame kernel at a position of high electric field strength around the central electrode. It was observed that the electric field strength in the air gap between the coaxial cylindrical electrodes was increased further by applying a shorter pulse. It was also clarified that the shorter pulse improved ignitability even further.

  11. Ignition target design and robustness studies for the National Ignition Facility

    International Nuclear Information System (INIS)

    Recent results are presented from two-dimensional LASNEX calculations of the indirectly driven hohlraum and ignition capsules proposed for the National Ignition Facility (NIF). The calculations concentrate on two capsule designs, the baseline design which has a bromine-doped plastic ablator, and the beryllium design which has a copper-doped beryllium ablator. Both capsules have a cryogenic fuel layer. Primary emphasis in these calculations is placed upon robustness studies detailing various sensitivities. These studies fall naturally into two categories, those performed with integrated modeling where the capsule, hohlraum, and laser rays all are modeled simultaneously with the laser power levels as the only energy input, and those performed in a capsule-only mode where an externally imposed drive is applied to the exterior of the ignition capsule and only the capsule performance is modeled. Integrated modeling calculations address sensitivities to, e.g., the laser pointing; among other things, capsule-only calculations address yield degradation due to the growth of hydrodynamic instabilities seeded by initial surface roughnesses on the capsules. Limitations of the calculational models and directions for future research are discussed. The results of the robustness studies performed to date enhance the authors' confidence that the NIF can achieve ignition and produce 10--15 MJ of capsule yield with one or more capsule designs

  12. Development of a simulation model for compression ignition engine running with ignition improved blend

    Directory of Open Access Journals (Sweden)

    Sudeshkumar Ponnusamy Moranahalli

    2011-01-01

    Full Text Available Department of Automobile Engineering, Anna University, Chennai, India. The present work describes the thermodynamic and heat transfer models used in a computer program which simulates the diesel fuel and ignition improver blend to predict the combustion and emission characteristics of a direct injection compression ignition engine fuelled with ignition improver blend using classical two zone approach. One zone consists of pure air called non burning zone and other zone consist of fuel and combustion products called burning zone. First law of thermodynamics and state equations are applied in each of the two zones to yield cylinder temperatures and cylinder pressure histories. Using the two zone combustion model the combustion parameters and the chemical equilibrium composition were determined. To validate the model an experimental investigation has been conducted on a single cylinder direct injection diesel engine fuelled with 12% by volume of 2- ethoxy ethanol blend with diesel fuel. Addition of ignition improver blend to diesel fuel decreases the exhaust smoke and increases the thermal efficiency for the power outputs. It was observed that there is a good agreement between simulated and experimental results and the proposed model requires low computational time for a complete run.

  13. Integrated ignition calculations for indirectly driven targets

    International Nuclear Information System (INIS)

    We present two-dimensional LASNEX calculations of the hohlraum and ignition capsules proposed for the National Ignition Facility (NIF). Our current hohlraum design is a 2.76 mm radius, 9.49 mm long gold cylinder with 1.39 mm radius laser entrance holes (LEH) which are covered by 1 μm thick polyamide foils. Laser beams with less that 1.4 MJ total energy and less than 400 TW peak power irradiate the cylinder wall from two separate cones entering each LEH. The hohlraum interior is filled with hydrogen-helium gas (50-50 atomic) at a density of 0.83 mg/cm3 to suppress the inward expansion of the wall. The capsule uses either a 160 μm plastic ablator doped with bromine (the baseline design), or a 155 μm beryllium ablator doped with copper (the beryllium design). The ablator surrounds an 80 μm thick deuterium-tritium (DT) ice layer with an inner radius of 0.87 mm. We will show the results of integrated, two-dimensional calculations of the hohlraum and the capsule. Plasma conditions within the hohlraum will be described. Peak radiation temperatures in the hohlraum are about 300 eV. These calculations proceed through the implosion, ignition, and burn of the DT capsule. Current peak calculated yields are 12 MJ for the baseline design and 6.9 MJ for the capsule with the beryllium ablator, although higher yields should be achievable with improved ''tuning'' of the laser power levels

  14. Propellant-Flow-Actuated Rocket Engine Igniter

    Science.gov (United States)

    Wollen, Mark

    2013-01-01

    A rocket engine igniter has been created that uses a pneumatically driven hammer that, by specialized geometry, is induced into an oscillatory state that can be used to either repeatedly impact a piezoelectric crystal with sufficient force to generate a spark capable of initiating combustion, or can be used with any other system capable of generating a spark from direct oscillatory motion. This innovation uses the energy of flowing gaseous propellant, which by means of pressure differentials and kinetic motion, causes a hammer object to oscillate. The concept works by mass flows being induced through orifices on both sides of a cylindrical tube with one or more vent paths. As the mass flow enters the chamber, the pressure differential is caused because the hammer object is supplied with flow on one side and the other side is opened with access to the vent path. The object then crosses the vent opening and begins to slow because the pressure differential across the ball reverses due to the geometry in the tube. Eventually, the object stops because of the increasing pressure differential on the object until all of the kinetic energy has been transferred to the gas via compression. This is the point where the object reverses direction because of the pressure differential. This behavior excites a piezoelectric crystal via direct impact from the hammer object. The hammer strikes a piezoelectric crystal, then reverses direction, and the resultant high voltage created from the crystal is transferred via an electrode to a spark gap in the ignition zone, thereby providing a spark to ignite the engine. Magnets, or other retention methods, might be employed to favorably position the hammer object prior to start, but are not necessary to maintain the oscillatory behavior. Various manifestations of the igniter have been developed and tested to improve device efficiency, and some improved designs are capable of operation at gas flow rates of a fraction of a gram per second (0

  15. Low emissions compression ignited engine technology

    Science.gov (United States)

    Coleman, Gerald N.; Kilkenny, Jonathan P.; Fluga, Eric C.; Duffy, Kevin P.

    2007-04-03

    A method and apparatus for operating a compression ignition engine having a cylinder wall, a piston, and a head defining a combustion chamber. The method and apparatus includes delivering fuel substantially uniformly into the combustion chamber, the fuel being dispersed throughout the combustion chamber and spaced from the cylinder wall, delivering an oxidant into the combustion chamber sufficient to support combustion at a first predetermined combustion duration, and delivering a diluent into the combustion chamber sufficient to change the first predetermined combustion duration to a second predetermined combustion duration different from the first predetermined combustion duration.

  16. Imploding ignition waves: I. one dimensional analysis

    OpenAIRE

    Kushnir, Doron; Livne, Eli; Waxman, Eli

    2011-01-01

    We show that converging spherical and cylindrical shock waves may ignite a detonation wave in a combustible medium, provided the radius at which the shocks become strong exceeds a critical radius, R_c. An approximate analytic expression for R_c is derived for an ideal gas equation of state and a simple (power-law-Arrhenius) reaction law, and shown to reproduce the results of numerical solutions. For typical acetylene-air experiments we find R_c~0.1 mm (spherical) and R_c~1 mm (cylindrical). W...

  17. Fast ignition studies at Osaka University

    International Nuclear Information System (INIS)

    After the invention of the chirped pulse amplification technique [1], the extreme conditions of matters have become available in laboratory spaces and can be studied with the use of ultra intense laser pulse (UILP) with a high energy. One such example is the fast ignition [2] where UILP is used to heat a highly compressed fusion fuel core within 1-10 pico-seconds before the core disassembles. It is predicted possible with use of 50-100 kJ lasers for both imploding the fuel and heating [2] to attain a large fusion gain. Fast ignition was shown to be a promising new scheme for laser fusion [3] with a PW (= 1015 W) UILP and GEKKO XII laser systems at Osaka. Many new physics have been found with use of UILP in a relativistic parameter regime during the process of the fast ignition studies. UILP can penetrate into over-dense plasma for a couple hundred microns distance with a self-focusing and relativistic transparency effects. Hot electrons of 1-100 MeV can be easily created and are under studies for its spectral and emission angle controls. Strong magnetic fields of 10's of MGauss are created to guide these hot electrons along the target surface [4]. Based on these results, a new and largest UILP laser machine of 10 kJ energy at PW UILP peak power is under construction to test if we can achieve the sub-ignition fusion condition at Osaka University. The machine requires challenging optical technologies such as large size (0.9 m) gratings, tiling these gratings for UILP compression; segmenting four large UILP beams to obtain diffraction limited focal spot. We would like to over-view all of these activities. References [1]D. STRICKLAND and G. MOUROU, Opt. Commun., 56, 219 (1985) [2] S. ATZENI et al., Phys Plasmas, 6, 3316 (1999) [3] R. KODAMA, K.A. TANAKA et al., Nature, 418, 933 (2002) [4] A.L. LEI, K.A. TANAKA et al., Phys. Rev. Lett., 96, 255006(2006) ; H. HABARA, K.A. TANAKA et al., Phys. Rev. Lett., 97, 095004 (2006)

  18. A Compact Ring Design with Tunable Momentum Compaction

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.; /SLAC

    2012-05-17

    A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and predamping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

  19. Compact stellarator coils

    International Nuclear Information System (INIS)

    Experimental devices to study the physics of high-beta (β>∼4%), low aspect ratio (A<∼4.5) stellarator plasmas require coils that will produce plasmas satisfying a set of physics goals, provide experimental flexibility, and be practical to construct. In the course of designing a flexible coil set for the National Compact Stellarator Experiment, we have made several innovations that may be useful in future stellarator design efforts. These include: the use of Singular Value Decomposition methods for obtaining families of smooth current potentials on distant coil winding surfaces from which low current density solutions may be identified; the use of a Control Matrix Method for identifying which few of the many detailed elements of the stellarator boundary must be targeted if a coil set is to provide fields to control the essential physics of the plasma; the use of Genetic Algorithms for choosing an optimal set of discrete coils from a continuum of potential contours; the evaluation of alternate coil topologies for balancing the tradeoff between physics objective and engineering constraints; the development of a new coil optimization code for designing modular coils, and the identification of a 'natural' basis for describing current sheet distributions. (author)

  20. Compact toroid formation experiments

    International Nuclear Information System (INIS)

    We present the design and experimental performance of a compact toroid (CT) formation experiment. The device has co-axial electrode diameters of 0.9 m (inner) and 1.25 m (outer), and an electrode length of ∼ 1.2 m, including an expansion/drift section. The CT is formed by a 0.1--0.2 Tesla initial radial magnetic field embedded co-axial puff gas discharge. The gas puff is injected with an array of 60 pulsed solenoid driven fast valves. The formation discharge is driven by a 108 microfarad, 40 to 100 KV, 86 to 540 kilojoule 2 to 5 megamp capacitor discharge with ∼ 20 nanohenry initial total discharge inductance. The hardware includes transmission line connections for a Shiva Star (1300 microfarad, up to 120 KV, 0.4 megajoule) capacitor bank driven acceleration discharge. Experimental measurements include current, voltage; azimuthal, radial and axial magnetic field at numerous location; fast photography, optical spectroscopy; microwave, CO2 laser, and He-Ne laser interferometry. Auxiliary experiments include Penning ionization gauge, pressure probe, and breakdown gas trigger diagnostics of gas injection, and Hall probe measurements of magnetic field injection

  1. Compactable reactor waste characterization

    International Nuclear Information System (INIS)

    Compactable reactor wastes were characterized in respect of physical composition. β/γ activity levels, radionuclide inventory, and tritium and carbon-14 content. 1072 bags of waste representing 18 bales with a volume of 9 m3 were examined. This waste is extremely heterogeneous and can contain any item or material used at nuclear generating stations. The β/γ activity level of the waste is low; at the time of manufacture the 18 bales ranged between 1.0 and 6.94 mCi most of which was attributable to radionuclides with a half-life of one year or less. After ten years' decay the activity of any bale will have decreased to a maximum of 1.5 mCi and the only β/γ radionuclides of significance will be 60Co and 137Cs. Tritium and carbon-14 were found in most of the waste bags and it is estimated that a cubic metre of waste could contain 8.4 to 11.3 Ci of tritium and 0.8 to 5.4 μCi carbon-14. It is considered there is no need for further conditioning of this waste for disposal

  2. [{sup 123}I]IPCIT and [{sup 123}I]{beta}-CIT as SPECT tracers for the dopamine transporter A comparative analysis in nonhuman primates

    Energy Technology Data Exchange (ETDEWEB)

    Scanley, B.E. E-mail: ellen.scanley@yale.edu; Gandelman, M.S.; Laruelle, M.; Al-Tikriti, M.S.; Baldwin, R.M.; Zoghbi, S.S.; Hoffer, P.B.; Wang, S.; Neumeyer, J.L.; Innis, R.B

    2000-01-01

    [{sup 123}I]2{beta}-Carbomethoxy-3{beta}-(4-iodophenyl)tropane ([{sup 123}I]{beta}-CIT) and its isopropylester analog [{sup 123}I]IPCIT, both of which are phenyltropane derivatives of cocaine with high affinity for the dopamine (DA) transporter, were compared using single photon emission computed tomography in nonhuman primates. Although IPCIT is significantly more selective for the DA transporter than {beta}-CIT, striatal distribution volumes of specifically bound tracer were similar for both tracers. Compartmental modeling results were compared with a simple peak equilibrium method used previously by this group. The peak equilibrium method is shown to overestimate striatal distribution volumes, primarily due to a difference in the calculated time of peak specific uptake.

  3. Quelle place tient l'expérience des autres dans la formation d'un professionnel ? Apport et limite du récit professionnel

    OpenAIRE

    Beaujouan, Joffrey; Coutarel, Fabien; Daniellou, François

    2013-01-01

    Cet article s'intéresse à la construction de l'expérience d'un individu sous l'angle de la mise en évidence de la place que tient l'expérience des autres dans la formation d'un professionnel : comment et en quoi le récit professionnel d'autrui permettrait de produire sur ses destinataires des effets d'apprentissage et de développement. Le récit, circonscrit dans nos propos par sept principes constitutifs fondamentaux, est une façon de configurer et transmettre l'expérience immédiate des humai...

  4. Frégosi Franck, Penser l’islam dans la laïcité, Paris, Fayard, 2008, 496 p.

    Directory of Open Access Journals (Sweden)

    Katrine Rømhild Benkaaba

    2009-09-01

    Full Text Available Il est possible de « penser l’islam dans la laïcité », telle est la conclusion du livre de Franck Frégosi, issu de sa thèse d’HDR. L’ouvrage réunit plusieurs domaines qui ont été au centre des recherches de l’auteur : l’organisation et la régulation du culte musulman en France, la formation du personnel religieux, le droit islamique en interaction avec des contextes différents. Un processus d’échange mutuel est en marche, pose l’auteur, entre l’islam et la laïcité, deux systèmes de pensée qui...

  5. Reduction in camera-specific variability in [(123)I]FP-CIT SPECT outcome measures by image reconstruction optimized for multisite settings

    DEFF Research Database (Denmark)

    Buchert, Ralph; Kluge, Andreas; Tossici-Bolt, Livia;

    2016-01-01

    Southampton method with binding in the whole brain, occipital cortex or cerebellum as the reference. The correlation between SBR and age was used as the primary quality measure. RESULTS: The fraction of SBR variability explained by age was highest (1) with QSPECT, independently of the reference region, and (2......) with whole brain as the reference, independently of the reconstruction algorithm. CONCLUSION: QSPECT reconstruction appears to be useful for reduction of camera-specific intersubject variability of [(123)I]FP-CIT SPECT in multisite and single-site multicamera settings. Whole brain excluding striatal...... reconstruction algorithm for its ability to reduce camera-specific intersubject variability in [(123)I]FP-CIT SPECT. The secondary aim was to evaluate binding in whole brain (excluding striatum) as a reference for quantitative analysis. METHODS: Of 73 healthy subjects from the European Normal Control Database of...

  6. Serotonin transporters in dopamine transporter imaging: a head-to-head comparison of dopamine transporter SPECT radioligands 123I-FP-CIT and 123I-PE2I

    DEFF Research Database (Denmark)

    Ziebell, Morten; Holm-Hansen, Signe; Thomsen, Gerda; Wagner, Aase; Jensen, Peter; Pinborg, Lars H; Knudsen, Gitte Moos

    2010-01-01

    SPECT radioligands (123)I-2-β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)nortropane ((123)I-FP-CIT) and (123)I-N-(3-iodoprop-2E-enyl)-2-β-carbomethoxy-3β-(4-methylphenyl) nortropane ((123)I-PE2I), which has a 10-fold higher selectivity than (123)I-FP-CIT for DAT versus SERT [corrected]....

  7. Shock Timing Plan for the National Ignition Campaign

    Science.gov (United States)

    Munro, D. H.; Robey, H. F.; Spears, B. K.; Boehly, T. R.

    2006-10-01

    We report progress on the design of the shock timing tuning procedure for the 2010 ignition campaign at the National Ignition Facility. Our keyhole target design provides adequate drive surrogacy for us to time the first three shocks empirically. The major risk to our plan is hard x-ray preheat, which can cause the diagnostic window to become opaque.

  8. Comprehensive study of ignition and combustion of single wooden particles

    DEFF Research Database (Denmark)

    Momenikouchaksaraei, Maryam; Yin, Chungen; Kær, Søren Knudsen;

    2013-01-01

    How quickly large biomass particles can ignite and burn out when transported into a pulverized-fuel (pf) furnace and suddenly exposed to a hot gas flow containing oxygen is very important in biomass co-firing design and optimization. In this paper, the ignition and burnout of the largest possible...

  9. Boron Particle Ignition in Secondary Chamber of Ducted Rocket

    Directory of Open Access Journals (Sweden)

    J. X. Hu

    2012-01-01

    Full Text Available In the secondary chamber of ducted rocket, there exists a relative speed between boron particles and air stream. Hence, the ignition laws under static conditions cannot be simply applied to represent the actual ignition process of boron particles, and it is required to study the effect of forced convective on the ignition of boron particles. Preheating of boron particles in gas generator makes it possible to utilize the velocity difference between gas and particles in secondary chamber for removal of the liquid oxide layer with the aid of Stoke's forces. An ignition model of boron particles is formulated for the oxide layer removal by considering that it results from a boundary layer stripping mechanism. The shearing action exerted by the high-speed flow causes a boundary layer to be formed in the surface of the liquid oxide layer, and the stripping away of this layer accounts for the accelerated ignition of boron particles. Compared with the King model, as the ignition model of boron particles is formulated for the oxide layer removal by considering that it results from a boundary layer stripping mechanism, the oxide layer thickness thins at all times during the particle ignition and lower the ignition time.

  10. 49 CFR 392.50 - Ignition of fuel; prevention.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Ignition of fuel; prevention. 392.50 Section 392.50 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER... COMMERCIAL MOTOR VEHICLES Fueling Precautions § 392.50 Ignition of fuel; prevention. No driver or...

  11. 33 CFR 159.129 - Safety: Ignition prevention test.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety: Ignition prevention test... prevention test. (a) Components of a device that are a potential ignition source in an explosive atmosphere... locations (46 CFR 111.80-5(a)) need not be subjected to this testing....

  12. 16 CFR Figure 6 to Part 1610 - Igniter

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Igniter 6 Figure 6 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES Pt.1610, Fig. 6 Figure 6 to Part 1610—Igniter ER20OC08.001...

  13. Safety overview of the National Ignition Facility

    International Nuclear Information System (INIS)

    The National Ignition Facility (NIF) is a proposed US Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 laser beams onto a tiny deuterium- tritium target located at the center of a spherical target chamber. The NIF mission is to achieve inertial confinement fusion (ICF) ignition, access physical conditions in matter of interest to nuclear weapons physics, provide an above ground simulation capability for nuclear weapons effects testing, and contribute to the development of inertial fusion for electrical power production. The NIF has been classified as a radiological, low hazard facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis be prepared under DOE Order 5481.1B, Safety Analysis and Review System. A draft Preliminary Safety Analysis Report (PSAR) has been written, and this will be finalized later in 1996. This paper summarizes the safety issues associated with the operation of the NIF. It provides an overview of the hazards, estimates maximum routine and accidental exposures for the preferred site of LLNL, and concludes that the risks from NIF operations are low

  14. Ignition and high gain with ultrapowerful lasers

    International Nuclear Information System (INIS)

    Ultrahigh intensity lasers can potentially be used in conjunction with conventional fusion lasers to ignite inertial confinement fusion (ICF) capsules with a total energy of a few tens of kilojoules of laser light, and can possibly lead to high gain with as little as 100 kJ. A scheme is proposed with three phases. First, a capsule is imploded as in the conventional approach to inertial fusion to assemble a high-density fuel configuration. Second, a hole is bored through the capsule corona composed of ablated material, as the critical density is pushed close to the high-density core of the capsule by the ponderomotive force associated with high-intensity laser light. Finally, the fuel is ignited by suprathermal electrons, produced in the high-intensity laser--plasma interactions, which then propagate from critical density to this high-density core. This new scheme also drastically reduces the difficulty of the implosion, and thereby allows lower quality fabrication and less stringent beam quality and symmetry requirements from the implosion driver. The difficulty of the fusion scheme is transferred to the technological difficulty of producing the ultrahigh-intensity laser and of transporting this energy to the fuel

  15. Stockpile Stewardship and the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E

    2012-01-04

    The National Ignition Facility (NIF), the world's most energetic laser system, is operational at Lawrence Livermore National Laboratory (LLNL). Since the completion of the construction project in March 2009, NIF has completed nearly 150 target experiments for the National Ignition Campaign (NIC), High Energy Density Stewardship Science (HEDSS) in the areas of radiation transport, material dynamics at high pressure in the solid state, as well as fundamental science and other national security missions. NIF capabilities and infrastructure are in place to support all of its missions with over 50 X-ray, optical and nuclear diagnostic systems and the ability to shoot cryogenic targets and DT layered capsules. NIF is now qualified for use of tritium and other special materials as well as to perform high yield experiments and classified experiments. DT implosions with record indirect-drive neutron yield of 4.5 x 10{sup 14} neutrons have been achieved. A series of 43 experiments were successfully executed over a 27-day period, demonstrating the ability to perform precise experiments in new regimes of interest to HEDSS. This talk will provide an update of the progress on the NIF capabilities, NIC accomplishments, as well as HEDSS and fundamental science experimental results and an update of the experimental plans for the coming year.

  16. National Ignition Facility project acquisition plan

    International Nuclear Information System (INIS)

    The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility (NIF) Project. The scope of the plan describes the procurement activities and acquisition strategy for the following phases of the NIF Project, each of which receives either plant and capital equipment (PACE) or other project cost (OPC) funds: Title 1 and 2 design and Title 3 engineering (PACE); Optics manufacturing facilitization and pilot production (OPC); Convention facility construction (PACE); Procurement, installation, and acceptance testing of equipment (PACE); and Start-up (OPC). Activities that are part of the base Inertial Confinement Fusion (ICF) Program are not included in this plan. The University of California (UC), operating Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory, and Lockheed-Martin, which operates Sandia National Laboratory (SNL) and the University of Rochester Laboratory for Laser Energetics (UR-LLE), will conduct the acquisition of needed products and services in support of their assigned responsibilities within the NIF Project structure in accordance with their prime contracts with the Department of Energy (DOE). LLNL, designated as the lead Laboratory, will have responsibility for all procurements required for construction, installation, activation, and startup of the NIF

  17. A novel computer-assisted image analysis of [123I]β-CIT SPECT images improves the diagnostic accuracy of parkinsonian disorders

    International Nuclear Information System (INIS)

    The purpose of this study was to develop an observer-independent algorithm for the correct classification of dopamine transporter SPECT images as Parkinson's disease (PD), multiple system atrophy parkinson variant (MSA-P), progressive supranuclear palsy (PSP) or normal. A total of 60 subjects with clinically probable PD (n = 15), MSA-P (n = 15) and PSP (n = 15), and 15 age-matched healthy volunteers, were studied with the dopamine transporter ligand [123I]β-CIT. Parametric images of the specific-to-nondisplaceable equilibrium partition coefficient (BPND) were generated. Following a voxel-wise ANOVA, cut-off values were calculated from the voxel values of the resulting six post-hoc t-test maps. The percentages of the volume of an individual BPND image remaining below and above the cut-off values were determined. The higher percentage of image volume from all six cut-off matrices was used to classify an individual's image. For validation, the algorithm was compared to a conventional region of interest analysis. The predictive diagnostic accuracy of the algorithm in the correct assignment of a [123I]β-CIT SPECT image was 83.3% and increased to 93.3% on merging the MSA-P and PSP groups. In contrast the multinomial logistic regression of mean region of interest values of the caudate, putamen and midbrain revealed a diagnostic accuracy of 71.7%. In contrast to a rater-driven approach, this novel method was superior in classifying [123I]β-CIT-SPECT images as one of four diagnostic entities. In combination with the investigator-driven visual assessment of SPECT images, this clinical decision support tool would help to improve the diagnostic yield of [123I]β-CIT SPECT in patients presenting with parkinsonism at their initial visit. (orig.)

  18. A novel computer-assisted image analysis of [{sup 123}I]{beta}-CIT SPECT images improves the diagnostic accuracy of parkinsonian disorders

    Energy Technology Data Exchange (ETDEWEB)

    Goebel, Georg [Innsbruck Medical University, Department of Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Seppi, Klaus; Wenning, Gregor K.; Poewe, Werner; Scherfler, Christoph [Innsbruck Medical University, Department of Neurology, Innsbruck (Austria); Donnemiller, Eveline; Warwitz, Boris; Virgolini, Irene [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria)

    2011-04-15

    The purpose of this study was to develop an observer-independent algorithm for the correct classification of dopamine transporter SPECT images as Parkinson's disease (PD), multiple system atrophy parkinson variant (MSA-P), progressive supranuclear palsy (PSP) or normal. A total of 60 subjects with clinically probable PD (n = 15), MSA-P (n = 15) and PSP (n = 15), and 15 age-matched healthy volunteers, were studied with the dopamine transporter ligand [{sup 123}I]{beta}-CIT. Parametric images of the specific-to-nondisplaceable equilibrium partition coefficient (BP{sub ND}) were generated. Following a voxel-wise ANOVA, cut-off values were calculated from the voxel values of the resulting six post-hoc t-test maps. The percentages of the volume of an individual BP{sub ND} image remaining below and above the cut-off values were determined. The higher percentage of image volume from all six cut-off matrices was used to classify an individual's image. For validation, the algorithm was compared to a conventional region of interest analysis. The predictive diagnostic accuracy of the algorithm in the correct assignment of a [{sup 123}I]{beta}-CIT SPECT image was 83.3% and increased to 93.3% on merging the MSA-P and PSP groups. In contrast the multinomial logistic regression of mean region of interest values of the caudate, putamen and midbrain revealed a diagnostic accuracy of 71.7%. In contrast to a rater-driven approach, this novel method was superior in classifying [{sup 123}I]{beta}-CIT-SPECT images as one of four diagnostic entities. In combination with the investigator-driven visual assessment of SPECT images, this clinical decision support tool would help to improve the diagnostic yield of [{sup 123}I]{beta}-CIT SPECT in patients presenting with parkinsonism at their initial visit. (orig.)

  19. Recent performance results of the National Ignition Facility Beamlet demonstration project

    International Nuclear Information System (INIS)

    The laser driver for the National Ignition Facility will be a departure from previous inertial confinement fusion laser architecture of a master oscillator single pass power amplifier (MOPA) design. The laser will use multi-segment Nd:Glass amplifiers in a multipass cavity arrangement, which can be assembled into compact and cost effective arrays to deliver the required multi- megajoule energy to target. A single beam physics prototype, the Beamlet, has been in operation for over two years and has demonstrated the feasibility of this architecture. We present a short review of Beamlet's performance and limitations based on beam quality both at its fundamental and frequency converted wavelengths of 1.053 and 0.351 μm

  20. Ignition Dynamic Parameters for Coke in Cement Calciners

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The mathematical ignition model was established and researches of ignition dynamic parameters for coke in some typical coal samples from cement plants was carried out according to circumstances of coal combusted in cement plants.In order to get the ignitioin temperature Tpi of carbon particles more accurately,the temperature rising experimental method was used and the actual heating circumstances for pulverized coal in calciners(in cement plants)were also considered.With this method,the accurate determination of the ignition temperature of coke in coal was achieved,so as to get some ignition dynamic parameters.These research results provide a theoretical basis for investigating coal ignition characteristics more scientifically and more accurately.