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Sample records for cit compact ignition

  1. TSC (Tokamak Simulation Code) disruption scenarios and CIT (Compact Ignition Tokamak) vacuum vessel force evolution

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, R.O.; Peng, Y.K.M.; Strickler, D.J.; Jardin, S.C.

    1990-01-01

    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 F{sub R}={minus}12.0 MN/rad and F{sub Z}={minus}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 F{sub R} by 15-50{percent} 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.

  2. Socioeconomic information, Plainsboro area, New Jersey: Supplementary documentation for an environmental assessment for the CIT (Compact Ignition Tokamak) at PPPL

    Energy Technology Data Exchange (ETDEWEB)

    Bentz, L.K.; Bender, D.S.

    1987-07-01

    This report contains socioeconomic information on the Plainsboro, New Jersey, area, the proposed location of the Compact Ignition Tokamak (CIT) facility. It was prepared as supplemental information for an environmental assessment for the CIT at Princeton Plasma Physics Laboratory (PPPL). The report contains descriptions of the demographic, economic, and community resource characteristics, and, based on information available in early 1987, considers the socioeconomic effect of the proposed facility. In all areas examined, the anticipated socioeconomic impacts of the proposed CIT facility at PPPL are negligible or minimal. 29 refs., 8 figs., 24 tabs.

  3. Surface erosion and tritium inventory analysis for CIT (Compact Ignition Tokamak)

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, J.N. (Argonne National Lab., IL (USA)); Dylla, H.F. (Princeton Univ., NJ (USA). Plasma Physics Lab.); Pontau, A.E.; Wilson, K.L. (Sandia National Labs., Livermore, CA (USA))

    1990-09-01

    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 ({approximately}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.

  4. Vacuum vessel system design for the compact ignition tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Reddan, W. (Ebasco Services Inc., Princeton, NJ (USA))

    1990-05-01

    The compact ignition tokamak (CIT) is envisioned to be the test bed for the study of self- sustained, or ignited, fusion plasmas. The design basis for CIT is a 11-T toroidal field, 12-MA plasma current and peak fusion power of 500 MW. A major portion of this project is the vacuum vessel system, which includes the vacuum chamber, the divertor, first wall, and the robotics systems necessary to maintain the in-vessel components. The vacuum chamber is 2.1 m major radius torus with a D-shaped cross section. For hydrogenic species the base pressure is 10{sup {minus}7} Torr, with a total pumping speed of 5000 l/s. It is designed to withstand the forces resulting from plasma disruptions and be bakeable to approximately 350 {degree}C. A swept divertor and fixed limiters are provided. Both are carbon based structures designed to accommodate heat fluxes as large as 40 MW/m{sup 2} during the 5 s pulse. Articulated booms and manipulators will be deployed for in-vessel maintenance tasks, such as first wall removal/replacement and leak checking. This paper summarizes the engineering considerations and design status. In addition, the unique organization of the project's national design team, led by the Princeton Plasma Physics Laboratory, and the integration into this organization of the industrial consortium responsible for the design and fabrication of the vacuum vessel system is described.

  5. Ex-vessel remote maintenance for the Compact Ignition Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Spampinato, P.T.; Macdonald, D.

    1987-01-01

    The use of deuterium-tritium (D-T) fuel for operation of the Compact Ignition Tokamak (CIT) requires the use of remote handling technology to carry out maintenance operations on the machine. These operations consist in removing and repairing such components as diagnostic modules by using remotely operated maintenance equipment. The major equipment being developed for maintenance external to the plasma chamber includes a bridge-mounted manipulator system for test cell operations, decontamination (decon) equipment, hot cell equipment, and solid-radiation-waste-handling equipment. Wherever possible, the project will use commercially available equipment. Several areas of the maintenance system design were addressed in fiscal year (FY) 1987, including conceptual designs of manipulator systems, the start of a remote equipment research and development (RandD) program, and definition of the hot cell, decon, and equipment repair facility requirements. R and D work included preliminary demonstrations of remote handling operations on full-size, partial mock-ups of the CIT machine at the Oak Ridge National Laboratory (ORNL) Remote Operations and Maintenance Development (ROMD) Facility. 1 ref., 6 figs.

  6. Compact Ignition Tokamak Program: status of FEDC studies

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, C.A.

    1985-01-01

    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. (WRF)

  7. Power Radiated from ITER and CIT by Impurities

    Science.gov (United States)

    Cummings, J.; Cohen, S. A.; Hulse, R.; Post, D. E.; Redi, M. H.; Perkins, J.

    1990-07-01

    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 Z{sub eff}, 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.

  8. cits de voyage

    OpenAIRE

    Efthymiou, Loukia

    2011-01-01

    La présente recherche prend appui d’une part sur les textes viatiques d’un groupe de voyageuses françaises appartenant au milieu de l’enseignement secondaire féminin et d’autre part sur leurs dossiers personnels conservés aux Archives Nationales. Le profil socioprofessionnel de ces éducatrices commande le caractère spécifique de leur voyage (pays de destination, motif du voyage, contraintes temporelles et financières) et de son écriture (discours qui sous-tendent le récit). Par la publication...

  9. Cross-linking of dimeric CitS and GltS transport proteins

    NARCIS (Netherlands)

    Krupnik, Tomasz; Dobrowolski, Adam; Lolkema, Juke S.

    2011-01-01

    CitS of Klebsiella pneumoniae and GltS of Escherichia coli are Na(+)-dependent secondary transporters from different families that are believed to share the same fold and quaternary structure. A 10 kDa protein tag (Biotin Acceptor Domain [BAD]) was fused to the N-terminus of both proteins (CitS-BAD1

  10. Membrane topology of the Na+/citrate transporter CitS of Klebsiella pneumoniae by insertion mutagenesis

    NARCIS (Netherlands)

    Geest, Marleen van; Lolkema, Juke S.

    2000-01-01

    The sodium ion dependent citrate transporter of Klebsiella pneumoniae (CitS) is a member of the bacterial 2-hydroxycarboxylate transporter family. Membrane topology models of the protein. largely based on reporter molecule fusions to C-terninally truncated CitS molecules, indicate that the protein t

  11. Structure and elevator mechanism of the Na(+)-citrate transporter CitS

    NARCIS (Netherlands)

    Lolkema, Juke S; Slotboom, Dirk Jan

    2016-01-01

    The recently determined crystal structure of the bacterial Na(+)-citrate symporter CitS provides unexpected structural and mechanistic insights. The protein has a fold that has not been seen in other proteins, but the oligomeric state, domain organization and proposed transport mechanism strongly re

  12. A statewide Crisis Intervention Team (CIT) initiative: evolution of the Georgia CIT program.

    Science.gov (United States)

    Oliva, Janet R; Compton, Michael T

    2008-01-01

    In late 2004, Georgia began implementation of a statewide Crisis Intervention Team (CIT) program to train a portion of its law enforcement officers to respond safely and effectively to individuals with mental illnesses who are in crisis. This overview provides a description of the evolution of the Georgia CIT, including discussions of the historical context in which the program developed; the program's vision, mission, and objectives; the importance of the multidisciplinary Georgia CIT Advisory Board; the training curriculum; the role played by state and local coordinators; the value of stakeholders' meetings; practical operations of the program; the importance of considering the adequacy of community-based and hospital-based psychiatric services; costs and funding; the program's expansion plan; and evaluation, research, and academic collaborations. These detailed descriptions of the Georgia CIT program may be useful for professionals involved in local, regional, or state CIT program planning and may provide a practical synopsis of one example of this collaborative model that is being rapidly disseminated across the U.S.

  13. 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}.

  14. 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.

  15. 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.

  16. 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...

  17. [{sup 125}I]{beta}-CIT-FE and [{sup 125}I]{beta}-CIT-FP are superior to [{sup 125}I]{beta}-CIT for dopamine transporter visualization: Autoradiographic evaluation in the human brain

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Ilonka; Hall, Haakan; Halldin, Christer; Swahn, Carl-Gunnar; Farde, Lars; Sedvall, Goeran

    1997-10-01

    The binding of the three dopamine transporter radioligands ([{sup 125}I]{beta}-CIT, [{sup 125}I]{beta}-CIT-FE, and [{sup 125}I]{beta}-CIT-FP) was studied using whole-hemisphere autoradiography on postmortem human brains. The autoradiograms revealed an intense and homogeneous labeling of the nucleus caudatus and putamen but also to varying extent to serotonergic and noradrenergic transporters of neocortex and thalamus. The order of specificity estimated (striatum over neocortex ratios) was {beta}-CIT-FP > {beta}-CIT-FE >> {beta}-CIT, suggesting that {beta}-CIT-FE and {beta}-CIT-FP should be preferred for in vivo studies of the dopamine transporter in the human brain.

  18. Regulation and expression of the metal citrate transporter CitM of Bacillus subtilis

    NARCIS (Netherlands)

    de Jonge - Warner, Jessica

    2002-01-01

    The main topic of this thesis is the regulation of transcription of the citM gene of Bacillus subtilis, encoding the major metal citrate transporter. CitM belongs to a small family of secondary transport proteins, the MeCit family, that is comprised of 12 members. CitM mediates the transport of meta

  19. 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...

  20. Projection structure of the secondary citrate/sodium symporter CitS at 6 Å resolution by electron crystallography.

    Science.gov (United States)

    Kebbel, Fabian; Kurz, Mareike; Grütter, Markus G; Stahlberg, Henning

    2012-04-20

    CitS from Klebsiella pneumoniae acts as a secondary symporter of citrate and sodium ions across the inner membrane of the host. The protein is the best characterized member of the 2-hydroxycarboxylate transporter family, while no experimental structural information at sub-nanometer resolution is available on this class of membrane proteins. Here, we applied electron crystallography to two-dimensional crystals of CitS. Carbon-film-adsorbed tubular two-dimensional crystals were studied by cryo-electron microscopy, producing the 6-Å-resolution projection structure of the membrane-embedded protein. In the p22(1)2(1)-symmetrized projection map, the predicted dimeric structure is clearly visible. Each monomeric unit can tentatively be interpreted as being composed of 11 transmembrane α-helices. In projection, CitS shows a high degree of structural similarity to NhaP1, the Na(+)/H(+) antiporter of Methanococcus jannaschii. We discuss possible locations for the dimer interface and models for the helical arrangements and domain organizations of the symporter based on existing models.

  1. The Astrosphere of the Asymptotic Giant Branch Star CIT 6

    Science.gov (United States)

    Sahai, Raghvendra; Mack-Crane, Galen P.

    2014-10-01

    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 ~15' (~18'). These structures most likely represent the astrosphere resulting from the shock interaction of CIT 6's molecular wind with the warm interstellar medium (ISM), 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 M ⊙ or larger, assuming a constant mass-loss rate of 3.2 × 10-6 M ⊙ yr-1. 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 CIT 6 is moving at a speed of about gsim39 (0.17 cm-3/n ISM)1/2 km s-1 through the ISM around it. However, comparisons with published numerical simulations and analytical modeling shows that CIT 6's forward shock (the northern ring) departs from the parabolic shape expected in steady state. We discuss several possible explanations for this departure.

  2. The astrosphere of the asymptotic giant branch star CIT 6

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, Raghvendra [Jet Propulsion Laboratory, MS 183-900, California Institute of Technology, Pasadena, CA 91109 (United States); Mack-Crane, Galen P., E-mail: sahai@jpl.nasa.gov [Department of Physics, Occidental College, Los Angeles, CA 90041 (United States)

    2014-10-01

    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 ∼15' (∼18'). These structures most likely represent the astrosphere resulting from the shock interaction of CIT 6's molecular wind with the warm interstellar medium (ISM), 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 M {sub ☉} or larger, assuming a constant mass-loss rate of 3.2 × 10{sup –6} M {sub ☉} yr{sup –1}. 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 CIT 6 is moving at a speed of about ≳39 (0.17 cm{sup –3}/n {sub ISM}){sup 1/2} km s{sup –1} through the ISM around it. However, comparisons with published numerical simulations and analytical modeling shows that CIT 6's forward shock (the northern ring) departs from the parabolic shape expected in steady state. We discuss several possible explanations for this departureþ.

  3. 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 ...

  4. Dual coil ignition system

    Energy Technology Data Exchange (ETDEWEB)

    Huberts, Garlan J.; Qu, Qiuping; Czekala, Michael Damian

    2017-03-28

    A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.

  5. HIGH-RESOLUTION CO OBSERVATION OF THE CARBON STAR CIT 6 REVEALING THE SPIRAL STRUCTURE AND A NASCENT BIPOLAR OUTFLOW

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyosun; Liu, Sheng-Yuan; Hirano, Naomi; Zhao-Geisler, Ronny; Trejo, Alfonso; Yen, Hsi-Wei; Taam, Ronald E.; Kemper, Francisca [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Kim, Jongsoo; Byun, Do-Young; Liu, Tie, E-mail: hkim@asiaa.sinica.edu.tw [Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

    2015-11-20

    CIT 6 is a carbon star in the transitional phase from the asymptotic giant branch (AGB) to the protoplanetary nebulae (pPNs). Observational evidences of two point sources in the optical, circumstellar arc segments in an HC{sub 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 {sup 12}CO J = 2–1 and {sup 13}CO J = 2–1 observations of CIT 6 with the Submillimeter Array combined with the Submillimeter Telescope (single-dish) data. The {sup 12}CO channel maps reveal a spiral-shell pattern connecting the HC{sub 3}N segments in a continuous form and an asymmetric outflow corresponding to the near-infrared bipolar nebula. Rotation of the {sup 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 presence of an anisotropic mass loss to the west and a double spiral pattern. The lack of interarm emission to the west may indicate a feature corresponding to the periastron passage of a highly eccentric orbit of the binary. Spatially averaged radial and spectral profiles of {sup 12}CO J = 2–1 and {sup 13}CO J = 2–1 are compared with simple spherical radiative transfer models, suggesting a change of {sup 12}CO/{sup 13}CO abundance ratio from ∼30 to ∼50 inward in the CSE of CIT 6. The millimeter continuum emission is decomposed into extended dust thermal emission (spectral index ∼ −2.4) and compact emission from radio photosphere (spectral index ∼ −2.0)

  6. [{sup 18}F]{beta}-CIT-FP is superior to [{sup 11}C]{beta}-CIT-FP for quantitation of the dopamine transporter

    Energy Technology Data Exchange (ETDEWEB)

    Lundkvist, Camilla; Halldin, Christer; Ginovart, Nathalie; Swahn, Carl-Gunnar; Farde, Lars

    1997-10-01

    {beta}-CIT-FP [N-(3-fluoropropyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane] is a cocaine analogue with high affinity for the dopamine transporter. Positron emission tomography (PET) studies with [O-methyl-{sup 11}C]{beta}-CIT-FP ([{sup 11}C]{beta}-CIT-FP) has shown that equilibrium conditions were approached but, however, not reached at the end of measurement. Moreover, metabolite studies of [{sup 11}C]{beta}-CIT-FP in monkey plasma demonstrated a lipophilic-labelled metabolite that may enter the brain. We therefore labelled {beta}-CIT-FP with fluorine-18 in a position that may avoid the formation of labelled lipophilic metabolites. The more long-lived radionuclide ({sup 18}F) was used to allow for measurements over longer time. [N-fluoropropyl-{sup 18}F]{beta}-CIT-FP ([{sup 18}F]{beta}-CIT-FP) was prepared by N-alkylation of nor-{beta}-CIT with [{sup 18}F]fluoropropyl bromide. PET studies were performed in cynomolgus monkeys. [{sup 18}F]{beta}-CIT-FP entered the brain rapidly. There was a high concentration of radioactivity in the striatum and much lower in the thalamus, neocortex, and cerebellum. The striatum-to-cerebellum ratio was about 5 at time of transient equilibrium, which occurred after 60 to 100 min. After pretreatment with GBR 12909, radioactivity in the striatum was markedly reduced, thus indicating specific [{sup 18}F]{beta}-CIT-FP binding to the dopamine transporter. The fraction of unchanged [{sup 18}F]{beta}-CIT-FP determined by HPLC was 10-15% after 140 min. No lipophilic labelled metabolites were detected. The absence of measurable lipophilic labelled metabolites and the occurrence of transient equilibrium within the time of the PET measurement indicate that [{sup 18}F]{beta}-CIT-FP is superior to [{sup 11}C]{beta}-CIT-FP as a PET radioligand for quantification of the dopamine transporter in the human brain.

  7. Interactive test tool for interoperable C-ITS development

    NARCIS (Netherlands)

    Voronov, A.; Englund, C.; Bengtsson, H.H.; Chen, L.; Ploeg, J.; Jongh, J.F.C.M. de; Sluis, H.J.D. van de

    2015-01-01

    This paper presents the architecture of an Interactive Test Tool (ITT) for interoperability testing of Cooperative Intelligent Transport Systems (C-ITS). Cooperative systems are developed by different manufacturers at different locations, which makes interoperability testing a tedious task. Up until

  8. Implosion Hydrodynamics of Fast Ignition Targets

    Science.gov (United States)

    Stephens, R. B.

    2004-11-01

    The fast ignition (FI) concept requires the generation of a compact, dense, pure fuel mass accessible to an external ignition source. The current baseline 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 ultra-intense laser pulse focused to the inside cone tip generates high-energy electrons to ignite the dense fuel. We have theoretically and experimentally investigated the collapse of such targets, validating modeling and exploring the tradeoffs 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 this 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 the hot spot must be controlled; for FI it is a liability. The hot, low-density inner core simply impedes the collapse of the cold fuel, lowering the implosion/burn efficiency and the gain while making ignition more difficult. We discuss approaches to minimizing this effect and experimental tests.

  9. Stability of Ignition Transients

    Directory of Open Access Journals (Sweden)

    V.E. Zarko

    1991-07-01

    Full Text Available The problem of ignition stability arises in the case of the action of intense external heat stimuli when, resulting from the cut-off of solid substance heating, momentary ignition is followed by extinction. Physical pattern of solid propellant ignition is considered and ignition criteria available in the literature are discussed. It is shown that the above mentioned problem amounts to transient burning at a given arbitrary temperature distribution in the condensed phase. A brief survey of published data on experimental and theoretical studies on ignition stability is offered. The comparison between theory and experiment is shown to prove qualitatively the efficiency of the phenomenological approach in the theory. However, the methods of mathematical simulation as well as those of experimental studying of ignition phenomenon, especially at high fluxes, need to be improved.

  10. Police officer perceptions of the impact of Crisis Intervention Team (CIT) programs.

    Science.gov (United States)

    Bonfine, Natalie; Ritter, Christian; Munetz, Mark R

    2014-01-01

    The Crisis Intervention Team (CIT) program is an approach for law enforcement officers to safely response to individuals who are experiencing a mental health crisis. Research must identify the components of CIT that are instrumental to the overall effectiveness of the program. For instance, recent studies report that CIT may have a transformative effect on officers' attitudes by increasing exposure to and familiarity with mental illness. This study explores this possibility further by examining 57 CIT officers' experiences with mental illness and attitudes about CIT. Specifically, we assessed how personal and professional exposure to mental illness associates with officers' perceptions about CIT generally, as well as with opinions about the officers' confidence in their abilities and the perceived effectiveness of the police department in responding to individuals in mental health crisis. Our findings indicate that CIT is rated very positively by officers. We found that officers' attitudes about the impact of CIT on improving overall safety, accessibility of services, officer skills and techniques, and the preparedness of officers to handle calls involving persons with mental illness are positively associated with officers' confidence in their abilities or with officers' perceptions of overall departmental effectiveness. There is further evidence that personal contact with individuals with mental illness affects the relationship between attitudes that CIT impacts overall safety and perceived departmental effectiveness. The results of this exploratory study underscore the importance of CIT officers' perceptions of key elements of CIT and the role of exposure to mental illness in examining program effectiveness.

  11. CitI, a Transcription Factor Involved in Regulation of Citrate Metabolism in Lactic Acid Bacteria†

    Science.gov (United States)

    Martin, Mauricio G.; Magni, Christian; de Mendoza, Diego; López, Paloma

    2005-01-01

    A large variety of lactic acid bacteria (LAB) can utilize citrate under fermentative conditions. Although much information concerning the metabolic pathways leading to citrate utilization by LAB has been gathered, the mechanisms regulating these pathways are obscure. In Weissella paramesenteroides (formerly called Leuconostoc paramesenteroides), transcription of the citMDEFCGRP citrate operon and the upstream divergent gene citI is induced by the presence of citrate in the medium. Although genetic experiments have suggested that CitI is a transcriptional activator whose activity can be modulated in response to citrate availability, specific details of the interaction between CitI and DNA remained unknown. In this study, we show that CitI recognizes two A+T-rich operator sites located between citI and citM and that the DNA-binding affinity of CitI is increased by citrate. Subsequently, this citrate signal propagation leads to the activation of the cit operon through an enhanced recruitment of RNA polymerase to its promoters. Our results indicate that the control of CitI by the cellular pools of citrate provides a mechanism for sensing the availability of citrate and adjusting the expression of the cit operon accordingly. In addition, this is the first reported example of a transcription factor directly functioning as a citrate-activated switch allowing the cell to optimize the generation of metabolic energy. PMID:16030208

  12. Implosion hydrodynamics of fast ignition targetsa)

    Science.gov (United States)

    Stephens, R. B.; Hatchett, S. P.; Tabak, M.; Stoeckl, C.; Shiraga, H.; Fujioka, S.; Bonino, M.; Nikroo, A.; Petrasso, R.; Sangster, T. C.; Smith, J.; Tanaka, K. A.

    2005-05-01

    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.

  13. Loop VIII/IX of the Na+-citrate transporter CitS of Klebsiella pneumoniae folds into an amphipathic surface helix

    NARCIS (Netherlands)

    Sobczak, [No Value; Lolkema, JS; Sobczak, Iwona

    2005-01-01

    The sodium ion-dependent citrate transporter CitS of Klebsiella pneumoniae is a member of, the 2-hydroxycarboxylate transporter (2HCT) family whose members transport divalent citrate in symport with two sodium ions. Profiles of the hydrophobic moment suggested the presence of an amphipathic helical

  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. Laser Diode Ignition (LDI)

    Science.gov (United States)

    Kass, William J.; Andrews, Larry A.; Boney, Craig M.; Chow, Weng W.; Clements, James W.; Merson, John A.; Salas, F. Jim; Williams, Randy J.; Hinkle, Lane R.

    1994-01-01

    This paper reviews the status of the Laser Diode Ignition (LDI) program at Sandia National Labs. One watt laser diodes have been characterized for use with a single explosive actuator. Extensive measurements of the effect of electrostatic discharge (ESD) pulses on the laser diode optical output have been made. Characterization of optical fiber and connectors over temperature has been done. Multiple laser diodes have been packaged to ignite multiple explosive devices and an eight element laser diode array has been recently tested by igniting eight explosive devices at predetermined 100 ms intervals.

  16. LA PASSION DE HALLÂJ : ENTRE LE RÉCIT FACTUEL ET LE RÉCIT FICTIONNEL LA PASSION DE HALLÂJ : ENTRE LE RÉCIT FACTUEL ET LE RÉCIT FICTIONNEL

    Directory of Open Access Journals (Sweden)

    Eqbal Samir Khalifa

    2009-04-01

    Full Text Available Hallâj est l’une des personnalités les plus éminentes du soufisme. Un grand procès politique et religieux, qui opposa, à Bagdad, en 309/922, Shi‘ites et Sunnites, juristes et Soufis, l'excommunia et le condamna au gibet, pour avoir prêché l’identification du mystique à Dieu, par amour. L’objectif de ce travail est de faire une comparaison de deux oeuvres française et égyptienne, qui se sont penchées sur la vie de ce Soufi, en l’occurrence, un récit factuel, le premier tome de « La passion de Hallâj » de Louis Massignon, et un récit fictionnel, la pièce de théâtre de Salah Abd Al-Sabour, « Le drame de Hallâj ». Cette étude procède par deux étapes. La première s’attarde sur les stratégies argumentatives adoptées par Massignon pour réhabiliter Hallâj. La seconde propose une lecture « palimpsestueuse » du récit fictionnel, qui fait résonner un nouveau discours sur Hallâj.Hallâj est l’une des personnalités les plus éminentes du soufisme. Un grand procès politique et religieux, qui opposa, à Bagdad, en 309/922, Shi‘ites et Sunnites, juristes et Soufis, l'excommunia et le condamna au gibet, pour avoir prêché l’identification du mystique à Dieu, par amour. L’objectif de ce travail est de faire une comparaison de deux oeuvres française et égyptienne, qui se sont penchées sur la vie de ce Soufi, en l’occurrence, un récit factuel, le premier tome de « La passion de Hallâj » de Massignon, et un récit fictionnel, la pièce de théâtre de Salah Abd Al-Sabour, « Le drame de Hallâj ». Cette étude procède par deux étapes. La première s’attarde sur les stratégies argumentatives adoptées par Massignon pour réhabiliter Hallâj. La seconde propose une lecture « palimpsestueuse » du récit fictionnel, qui fait résonner un nouveau discours sur Hallâj.

  17. 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...

  18. A technique for extending by ~103 the dynamic range of compact proton spectrometers for diagnosing ICF implosions on the National Ignition Facility and OMEGAa)

    Energy Technology Data Exchange (ETDEWEB)

    Sio, H. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Séguin, F. H. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Frenje, J. A. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Gatu Johnson, M. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Zylstra, A. B. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Rinderknecht, H. G. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Rosenberg, M. J. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Li, C. K. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA; Petrasso, R. D. [Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA

    2014-11-01

    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. Finally, 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.

  19. 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.

  20. National Ignition Facility design, performance, and cost

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, W.J.; Paisner, J.A.; Lowdermilk, W.H. [and others

    1994-09-16

    A conceptual design for the National Ignition Facility (NIF) has been completed and its cost has been estimated by a multilaboratory team. To maximize the performance/cost ratio a compact, segmented amplifier is used in a multipass architecture. Many recent optical and laser technology developments have been incorporated into the final design. The Beamlet project has successfully demonstrated the new concept. The mission of ICF Program using the NEF is to achieve ignition and gain in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects experiments, and for civilian applications such as inertial fusion energy development and fundamental studies of matter at high energy density.

  1. 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...

  2. Compact Orthoalgebras

    CERN Document Server

    Wilce, A

    2004-01-01

    We initiate a study of topological orthoalgebras (TOAs), concentrating on the compact case. Examples of TOAs include topological orthomodular lattices, and also the projection lattice of a Hilbert space. As the latter example illustrates, a lattice-ordered TOA need not be a topological lattice. However, we show that a compact Boolean TOA is a topological Boolean algebra. Using this, we prove that any compact regular TOA is atomistic, and has a compact center. We prove also that any compact TOA with isolated 0 is of finite height. We then focus on stably ordered TOAs: those in which the upper-set generated by an open set is open. These include both topological orthomodular lattices and interval orthoalgebras -- in particular, projection lattices. We show that the topology of a compact stably-ordered TOA with isolated 0 is determined by that of of its space of atoms.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Burner ignition system

    Science.gov (United States)

    Carignan, Forest J.

    1986-01-21

    An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.

  8. Experimental Investigation on the Ignition Delay Time of Plasma-Assisted Ignition

    Science.gov (United States)

    Xiao, Yang; Yu, Jin-Lu; He, Li-Ming; Jiang, Yong-Jian; Wu, Yong

    2016-09-01

    This paper investigates the ignition performances of plasma-assisted ignition in propane/air mixture. The results show that a shorter ignition delay time is obtained for the plasma ignition than the spark ignition and the average ignition delay time of plasma-assisted ignition can be reduced at least by 50%. The influence of air flow rate of combustor, the arc current and argon flow rate of plasma igniter on ignition delay time are also investigated. The ignition delay time of plasma-assisted ignition increases with increasing air flow rate in the combustor. By increasing the arc current, the plasma ignition will gain more ignition energy to ignite the mixture more easily. The influence of plasma ignition argon flow rates on the ignition delay time is quite minor.

  9. Autopsy validation of 123I-FP-CIT dopaminergic neuroimaging for the diagnosis of DLB

    Science.gov (United States)

    Attems, Johannes; Colloby, Sean J.; O'Brien, John T.; McKeith, Ian; Walker, Rodney; Lee, Lean; Burn, David; Lett, Debra J.; Walker, Zuzana

    2017-01-01

    Objective: To conduct a validation study of 123I-N-fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl) nortropane (123I-FP-CIT) SPECT dopaminergic imaging in the clinical diagnosis of dementia with Lewy bodies (DLB) with autopsy as the gold standard. Methods: Patients >60 years of age with dementia who had undergone 123I-FP-CIT imaging in research studies and who had donated their brain tissue to the Newcastle Brain Tissue Resource were included. All had structured clinical research assessments, and clinical diagnoses were applied by consensus panels using international diagnostic criteria. All underwent 123I-FP-CIT imaging at baseline, and scans were rated as normal or abnormal by blinded raters. Patients were reviewed in prospective studies and after death underwent detailed autopsy assessment, and neuropathologic diagnoses were applied with the use of standard international criteria. Results: Fifty-five patients (33 with DLB and 22 with Alzheimer disease) were included. Against autopsy diagnosis, 123I-FP-CIT had a balanced diagnostic accuracy of 86% (sensitivity 80%, specificity 92%) compared with clinical diagnosis, which had an accuracy of 79% (sensitivity 87%, specificity 72%). Among patients with DLB, 10% (3 patients) met pathologic criteria for Lewy body disease but had normal 123I-FP-CIT imaging. Conclusions: This large autopsy analysis of 123I-FP-CIT imaging in dementia demonstrates that it is a valid and accurate biomarker for DLB, and the high specificity compared with clinical diagnosis (20% higher) is clinically important. The results need to be replicated with patients recruited from a wider range of settings, including movement disorder clinics and general practice. While an abnormal 123I-FP-CIT scan strongly supports Lewy body disease, a normal scan does not exclude DLB with minimal brainstem involvement. Classification of evidence: This study provides Class I evidence that 123I-FP-CIT dopaminergic neuroimaging accurately identifies patients with DLB

  10. 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.

  11. 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.

  12. 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.

  13. Improving police response to persons with mental illness: a multi-level conceptualization of CIT.

    Science.gov (United States)

    Watson, Amy C; Morabito, Melissa Schaefer; Draine, Jeffrey; Ottati, Victor

    2008-01-01

    The large numbers of people with mental illness in jails and prisons has fueled policy concern in all domains of the justice system. This includes police practice, where initial decisions to involve persons in the justice system or divert them to mental health services are made. One approach to focus police response in these situations is the implementation of Crisis Intervention Teams (CIT). The CIT model is being implemented widely, with over 400 programs currently operating. While the limited evidence on CIT effectiveness is promising, research on CIT is limited in scope and conceptualization-much of it focusing on officer characteristics and training. In this paper we review the literature on CIT and present a conceptual model of police response to persons with mental illness that accounts for officer, organizational, mental health system and community level factors likely to influence implementation and effectiveness of CIT and other approaches. By moving our conceptualizations and research in this area to new levels of specificity, we may contribute more to effectiveness research on these interventions.

  14. National Ignition Facility under fire over ignition failure

    Science.gov (United States)

    Allen, Michael

    2016-08-01

    The 3.5bn National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in California is no nearer to igniting a sustainable nuclear fusion burn - four years after its initial target date - according to a report by the US National Nuclear Security Administration (NNSA).

  15. Auroville, une cité utopique en Inde

    Directory of Open Access Journals (Sweden)

    Chloé Maurel

    2012-12-01

    Full Text Available La communauté « Auroville », vaste cité internationale inaugurée le 28 février 1968 en Inde sur la baie du Bengale, à 10 kilomètres de Pondichéry, est une entreprise utopique et libertaire qui vise à réal iser « l’unité humaine » et une cohabitation harmonieuse et épanouie entre les hommes. Elle est fondée sur l’enseignement de Sri Aurobindo, penseur indien mort en 1950. Si au fi l du temps cette communauté n’a pas obtenu le succès espéré en termes de croissance de population, puisqu’elle compte actuellement 1 700 Aurovilliens, alors qu’elle avait été prévue pour en accueillir 50 000, on constate toutefois une implantation durable de cette entreprise sur le sol indien depuis près de quarante ans maintenant. De nouvelles générations arrivent, de nombreux Indiens locaux candidatent pour être intégrés à la communauté, Auroville est devenu un lieu très connu et touristique en Inde, et est reconnu officiellement par le gouvernement indien comme par l’Unesco. Mais qu’est au fond Auroville ? Groupement ésotérique aux allures de secte pour certains, entreprise néo-colonaliste pour d’autres (en effet i l y a un fort décalage de niveau de vie sur place entre les Occidentaux et les Indiens locaux, vestiges de l’utopie soixante-huitarde ou bien encore entreprise pionnière et espoir de paix et de fraternité internationale pour l’avenir ? Auroville apparaît ainsi sous de multiples facettes qui correspondent aux différentes façons, souvent radicalement opposées, dont elle est perçue. Il convient donc de se pencher avec plus d’attention sur cette entreprise originale pour essayer d’apporter un jugement objectif à son sujet. A cet effet il s’agira tout d’abord de rappeler l’histoire d’Auroville et de ses maîtres à penser, puis de présenter l’organisation de la cité et son évolution, en mettant l’accent sur le caractère novateur des activités qui y sont développées, pour

  16. Plastic ablator ignition capsule design for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D S; Haan, S W; Hammel, B A; Salmonson, J D; Callahan, D A; Town, R P

    2009-12-01

    The National Ignition Campaign, tasked with designing and fielding targets for fusion ignition experiments on the National Ignition Facility (NIF), has carried forward three complementary target designs for the past several years: a beryllium ablator design, a plastic ablator design, and a high-density carbon or synthetic diamond design. This paper describes current simulations and design optimization to develop the plastic ablator capsule design as a candidate for the first ignition attempt on NIF. The trade-offs in capsule scale and laser energy that must be made to achieve a comparable ignition probability to that with beryllium are emphasized. Large numbers of 1-D simulations, meant to assess the statistical behavior of the target design, as well as 2-D simulations to assess the target's susceptibility to Rayleigh-Taylor growth are presented.

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

    Science.gov (United States)

    Moses, Edward I.

    2016-10-01

    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 bum 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. NIP'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 FY20l0 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.

  18. Ignition of Nanoparticles by a Compact Camera Flash

    Science.gov (United States)

    2014-09-01

    output for different power settings of a Canon 580 XE II camera  flash  as seen by the  DET36A  fast  photodiode detector.  M1/1 and M1/128 represents the...lamp at and below M1/64 output setting of the Xe‐ flash .   The curves in Figure 2 are produced by the temporal response of the DET36A  fast  photodiode...photographic applications the timescale in Figure 2 is  fast   enough at any setting, but as we will describe later the pulse duration of the Xe‐ flash

  19. METHODOLOGY OF NEUROPSYCHOLOGICAL ASSESSMENT: QUALITATIVE (METASYNDROMAL ANALYSIS OF COGNITIVE DEFI CIT STRUCTURE) AND QUANTITATIVE (PSYCHOMETRIC ESTIMATE) ASPECTS

    OpenAIRE

    Yuri V. Mikadze

    2011-01-01

    Neuropsychological evaluation is a necessary step that precedes neurorehabilitation. It implies both qualitative and quantitative assessment of patients possible cognitive defi cit. Qualitative approach aims to defi ne the structure of the cognitive defi cit while quantitative procedures give estimate of the magnitude of the defi cit. Complex pathology aff ects multiple brain regions and reveals in a series of neuropsychological syndromes associated with these brain areas. Metasyndrome analys...

  20. Interpreting Shock Tube Ignition Data

    Science.gov (United States)

    2003-10-01

    times only for high concentrations (of order 1% fuel or greater). The requirements of engine (IC, HCCI , CI and SI) modelers also present a different...Paper 03F-61 Interpreting Shock Tube Ignition Data D. F. Davidson and R. K. Hanson Mechanical Engineering ... Engineering Department Stanford University, Stanford CA 94305 Abstract Chemical kinetic modelers make extensive use of shock tube ignition data

  1. Compact Vortices

    CERN Document Server

    Bazeia, D; Marques, M A; Menezes, R; Zafalan, I

    2016-01-01

    We study a family of Maxwell-Higgs models, described by the inclusion of a function of the scalar field that represent generalized magnetic permeability. We search for vortex configurations which obey first-order differential equations that solve the equations of motion. We first deal with the asymptotic behavior of the field configurations, and then implement a numerical study of the solutions, the energy density and the magnetic field. We work with the generalized permeability having distinct profiles, giving rise to new models, and we investigate how the vortices behave, compared with the solutions of the corresponding standard models. In particular, we show how to build compact vortices, that is, vortex solutions with the energy density and magnetic field vanishing outside a compact region of the plane.

  2. 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.

  3. 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.

  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. Self-ignition and ignition of aluminum powders in shock waves

    Science.gov (United States)

    Boiko, V. M.; Poplavski, S. V.

    Ignition of fine aluminum powders in reflected shock waves has been studied. Two ignition regimes are found: self-ignition observed at temperatures higher than 1800 K and ``low-temperature'' ignition at temperatures of 1000-1800 K. The possibility of initiating the ignition of aluminum powders in air using combustible liquids has been studied too.

  6. Fusion ignition research experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dale Meade

    2000-07-18

    Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is the largest remaining open issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The critical parts of this science can be obtained in a compact high field tokamak which is also likely to provide the fastest and least expensive path to understanding alpha-dominated plasmas in advanced toroidal systems.

  7. Mise en récits et en images des migrations

    OpenAIRE

    Canut, Cécile; Mazauric, Catherine

    2014-01-01

    International audience; Bien que très anciennes entre pays africains, les multiples formes de migrations transafricaines restent peu connues du public. Elles font pourtant l’objet de récits très nombreux, qui irriguent les productions artistiques (musicales, littéraires, théâtrales, cinématographiques, etc.), locales ou supra-nationales, depuis fort longtemps. Focalisant leurs analyses sur différents types de récits, les auteurs rendent compte, à travers les processus de mises en scène, de mi...

  8. 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 be optimal (CIT

  9. CitSci.org: A New Model for Managing, Documenting, and Sharing Citizen Science Data.

    Science.gov (United States)

    Wang, Yiwei; Kaplan, Nicole; Newman, Greg; Scarpino, Russell

    2015-10-01

    Citizen science projects have the potential to advance science by increasing the volume and variety of data, as well as innovation. Yet this potential has not been fully realized, in part because citizen science data are typically not widely shared and reused. To address this and related challenges, we built CitSci.org (see www.citsci.org), a customizable platform that allows users to collect and generate diverse datasets. We hope that CitSci.org will ultimately increase discoverability and confidence in citizen science observations, encouraging scientists to use such data in their own scientific research.

  10. 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;

    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....

  11. 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

  12. Projection Structure by Single-Particle Electron Microscopy of Secondary Transport Proteins GItT, Cits, and GltS

    NARCIS (Netherlands)

    Moscicka, Katarzyna B.; Krupnik, Tomasz; Boekema, Egbert J.; Lolkema, Juke S.; Mościcka, Katarzyna B.

    2009-01-01

    The structure of three secondary transporter proteins, GltT of Bacillus stearothermophilus, CitS of Klebsiella pneumoniae, and GltS of Escherichia coli, was studied. The proteins were purified to homogeneity ill detergent solution by Ni(2+)-NTA affinity chromatography, and the complexes were determi

  13. 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.

  14. The National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-06-03

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is a stadium-sized facility that, when completed in 2008, will contain 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 and will provide 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.

  15. A pedagogical framework for embedding C&IT into the curriculum

    Directory of Open Access Journals (Sweden)

    Grainne Conole

    1998-12-01

    Full Text Available A wide variety of communication and information technologies (C&IT is now available, offering education a broad range of potential benefits, be they educational (Mapp, 1994; Lewis and Merton, 1996; HEFCE, 1997a, economic (HEFCE, 1997a, or in terms of competitiveness with other universities in an increasingly global market (Maier et al, 1997. The uptake and use of these resources is patchy at best (Laurillard et al, 1993; Lewis and Merton, 1996. This mismatch between potential and use has been seen as increasingly important, and incentives and recommendations are leading to an increasing use of C&IT, as illustrated by the recommendations of the recent Dealing report (Dearing et al, 1997 and the priorities of the TLT programme (HEFCE, 1997b. Concerns have been voiced, however, that the push towards a wider embedding of C&IT in education may ignore issues of the appropriate uses of these resources. What is needed is a convincing and practical pedagogically-driven (as opposed to technology-driven methodology for integrating C&IT into courses.

  16. 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

  17. ICF Ignition, the Lawson Criterion, and Comparison with MFE Ignition

    Science.gov (United States)

    Betti, R.

    2009-11-01

    The Lawson criterion, which determines the onset of thermonuclear ignition, is usually expressed through the product pτ > 10 atm . s, where p is the plasma pressure in atm and τ is the energy confinement time in seconds. In magnetic fusion devices, both the pressure and confinement time are routinely measured and the performance of each discharge can be assessed by comparing the value of pτ with respect to the ignition value (10 atm . s). In inertial confinement fusion, both p and τ cannot be directly measured and the performance of surrogate and/or subignited ICF implosions cannot be assessed with respect to the ignition condition. This makes it difficult to compare the performance of ICF implosions with that of magnetic fusion energy (MFE) discharges. Here, we define the meaning of ignition in ICF implosions and compare it to MFE ignition. We then show that a multidimensional ignition condition for inertial confinement fusion can be cast in a form that depends on three measurable parameters of the compressed-fuel assembly: the hot-spot ion temperature T, the neutron yield normalized to the 1-D prediction (yield over clean or YOC) and the total areal density ρR, which includes the cold shell's contribution. A family of marginal-ignition curves are derived in the ρR--T plane.footnotetext C. D. Zhou and R. Betti, Phys. Plasmas 15, 102707 (2008). On this plane, hydrodynamic-equivalent curves show how a given implosion would perform with respect to the ignition condition when the laser-driver energy is varied. Such a criterion can be used to measure the ignition marginfootnotetext D. S. Clark, S. W. Haan, and J. D. Salmonson, Phys. Plasmas 15, 056305 (2008). of NIF targets and to predict the performance of OMEGA targets when scaled up to NIF energies. This work has been supported by the US Department of Energy under Cooperative Agreement Nos. DE-FC02-ER54789 and DE-FC52-08NA28302.

  18. La constitution du domaine de la Cité internationale universitaire de Paris

    Directory of Open Access Journals (Sweden)

    Brigitte Blanc

    2011-11-01

    Full Text Available La Cité internationale universitaire de Paris a été créée immédiatement après la première guerre mondiale pour favoriser les échanges et la rencontre entre les étudiants du monde entier. Conformément à la convention conclue en 1921 entre la Ville et l’Université de Paris, elle a été édifiée en bordure du parc Montsouris, sur des terrains situés à l’emplacement des anciennes fortifications de Thiers. Dès 1928, le rythme accéléré des constructions pose avec une certaine acuité le problème de l’extension du domaine. Celle-ci s’effectue par étapes durant l’Entre-deux-guerres, notamment aux dépens de la commune voisine de Gentilly. Mais dès le début des années cinquante, le projet de création du boulevard périphérique marque, pour la Cité internationale, la fin des possibilités d’agrandissement à partir du « site historique » du boulevard Jourdan. Aujourd’hui, la Cité se densifie et se développe « hors les murs ».The Cité internationale universitaire de Paris was created immediately after the First World War in order to encourage exchanges between university students from around the world. According to the 1921 convention established between the city and the University of Paris, the Cité was built along Montsouris Park, on lots previously occupied by the Thiers fortifications. Starting in 1928, the rapid development of the Cité made it necessary to extend the site. Between the two world wars, segments of the neighboring town of Gentilly were progressively annexed. But in the early 1950s, projects for the creation of a boulevard périphérique – beltway – made further extension impossible. Today, construction continues, both on-site and outside the walls of the historical Cité.

  19. 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.

  20. 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.

  1. Application of the CIT concept in the clinical environment: hurdles, practicalities, and clinical benefits.

    Science.gov (United States)

    Sterr, Annette; Szameitat, Andre; Shen, Shan; Freivogel, Susanna

    2006-03-01

    Basic neuroscience research on brain plasticity, motor learning, and recovery has stimulated new concepts in motor rehabilitation. Combined with the development of methodological goal standards in clinical outcome research, these findings have effectuated the introduction of a double-paradigm shift in physical rehabilitation: (a) the move toward evidence-based procedures and disablement models for the assessment of clinical outcome and (b) the introduction of training-based concepts that are theoretically founded in learning theory. A major drive for new interventions has further come from recent findings on the adaptive capacities of neural networks and their linkage to perception, performance, and long-term recovery. In this context, constraint-induced movement therapy, an intervention initially designed for upper-limb hemiparesis, represents the theoretically and empirically most thoroughly founded training concept. Several clinical trials on constraint-induced therapy (CIT) have shown its efficacy in higher functioning patients; however, the transfer of the treatment into standard health care seems slow. Survey research further suggests a rather poor acceptance of CIT among clinical staff and it seems that the implementation of CIT is hindered by barriers constructed of beliefs and assumptions that demand a critical and evidence-based discussion. Within this context, we have conducted a series of experiments on amended CIT protocols and their application in the clinical environment which addressed the following issues: (1) massed practice: are 6 hours of daily training inevitable to achieve clinical benefits? (2) practicality: what is feasible in the standard care setting and what are the clinical benefits achieved by "feasible compromise CIT protocols?" (3) apprehensions: are concerns on increased muscular tone and pathologic movement patterns justified, and (4) learned nonuse: is the assumption of "hidden" residual abilities valid so that it warrants the

  2. 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

  3. Enhanced Model for Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Rodney J. [Research Applications Corporation, Los Alamos, NM (United States)

    2010-10-12

    Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nation's energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, "implicitness and fluid modeling," can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

  4. Options for an ignited tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Sheffield, J.

    1984-02-01

    It is expected that the next phase of the fusion program will involve a tokamak with the goals of providing an ignited plasma for pulses of hundreds of seconds. A simple model is described in this memorandum which establishes the physics conditions for such a self-sustaining plasma, for given ion and electron thermal diffusivities, in terms of R/a, b/a, I, B/q, epsilon ..beta../sub p/, anti T/sub i/, and anti T/sub e//anti T/sub i/. The model is used to produce plots showing the wide range of tokamaks that may ignite or have a given ignition margin. The constraints that limit this range are discussed.

  5. 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.

  6. Isochoric implosions for fast ignition

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D S; Tabak, M

    2006-06-05

    Fast Ignition (FI) exploits the ignition of a dense, uniform fuel assembly by an external energy source to achieve high gain. In conventional ICF implosions, however, the fuel assembles as a dense shell surrounding a low density, high-pressure hotspot. Such configurations are far from optimal for FI. 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 implode a dense, quasi-uniform fuel assembly with minimal energy wastage in forming a hotspot. A scheme for realizing these specialized implosions in a practical ICF target is also described.

  7. 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

  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. "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...

  10. 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.

  11. 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

  12. PROPOFOL DECREASES 125Ⅰ-β-CIT BINDING TOTHE DOPAMINE TRANSPORTER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To determine the changes of brain dopamine transporter in mice receiving propofol anesthesia, 125Ⅰ-β-CIT binding sites were observed at different time course. Methods 1. Twenty-seven normal Kunming mice were ran domizedly divided into 3 groups (n=9) and received intraperitoneal injection of propofol 100, 200 mg /kg and 10% intralipid (as control)respectively. The time of losing righting reflex and displaying excitatory symptoms were recorded within 10min after administration. 2. Sixty Kunming mice were randomizedly assigned into 2 groups ( n = 30). The mice were given 125Ⅰ-β-CIT in travenously and propofol 200mg/kg or 10% intralipid (as control) intraperitoneally. Five mice in every group were killed at dif ferent time course and their brain removed to isolate cerebellar, hypothalamus, striatum and cerebral cortex. After weighting brain tissues, the radioactivity of 125Ⅰ-β-CIT in different brain tissue was measured. Results 1. The time of losing righting reflex was reduced from 319. 167 + 88.228s in propofol 100mg/kg group to 231. 667 + 46. 233s in propofol 200mg/kg group, and it fell from 193.75 + 27. 233s to 145. 556 + 27. 437s for presenting excitatory activity. 2. Propofol intraperitoneal groups significantly decreased the combination of 125Ⅰ-β-CIT and dopamine transporter in the striatum (P<0.01) and cerebral cortex (P <0.05) 120min after injection of propofol compared with the control group. But propofol increased the binding (P<0.05) in the striatum 30min after injection. Conclusion The inhibitive effect of propofol on dopamine transporter to uptake dopamine in mice brain may contribute to some anesthetic mechanisms.

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

    DEFF Research Database (Denmark)

    Koch, Walter; Unterrainer, Marcus; Xiong, Guoming;

    2014-01-01

    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...

  14. 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.

  15. 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.

  16. Functional Analysis of the Citrate Activator CitO from Enterococcus faecalis Implicates a Divalent Metal in Ligand Binding

    Science.gov (United States)

    Blancato, Víctor S.; Pagliai, Fernando A.; Magni, Christian; Gonzalez, Claudio F.; Lorca, Graciela L.

    2016-01-01

    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. PMID:26903980

  17. 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.

  18. 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.

  19. Compaction Behavior of Isomalt after Roll Compaction

    OpenAIRE

    2012-01-01

    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force....

  20. Self-ignition of diesel spray combustion

    Science.gov (United States)

    Dhuchakallaya, Isares; Watkins, A. P.

    2009-10-01

    This work presents the development and implementation of auto-ignition modelling for DI diesel engines by using the probability density function-eddy break-up (PDF-EBU) model. The key concept of this approach is to combine the chemical reaction rate dealing with low-temperature mode, and the turbulence reaction rate governing the high-temperature part by a reaction progress variable coupling function which represents the level of reaction. The average reaction rate here is evaluated by a PDF averaging approach. In order to assess the potential of this developed model, the well-known Shell ignition model is chosen to compare in auto-ignition analysis. In comparison, the PDF-EBU ignition model yields the ignition delay time in good agreement with the Shell ignition model prediction. However, the ignition kernel location predicted by the Shell model is slightly nearer injector than that by the PDF-EBU model leading to shorter lift-off length. As a result, the PDF-EBU ignition model developed here are fairly satisfactory in predicting the auto-ignition of diesel engines with the Shell ignition model.

  1. Selective oxidation behavior of an ignition-proof Mg-Y-Ca-Ce alloy

    Institute of Scientific and Technical Information of China (English)

    周娜; 章桢彦; 董杰; 靳丽; 丁文江

    2013-01-01

    A Mg-Y-Ca-Ce magnesium alloy was optimized for high ignition-proof property, which did not burn in air at 1233 K up to 30 min. Oxidation behavior of the alloy was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermodynamics calculation at 673, 773 and 873 K. XRD and SEM analysis indicated that dense and compact oxide films composed of MgO, Y2O3 and CaO formed. The oxidation behavior was characterized by the selective oxidation. Based on Pilling-Bedworth ra-tio (PBR) and energy dispersive spectrometer (EDS) analysis, Y2O3 contributed more to form the compact surface oxide film, which led to the excellent ignition-proof performance. The thermodynamics analysis and EDS results implied that the Y-rich areas were preferred paths for the selective oxidation.

  2. 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.

  3. Indirect drive ignition at the National Ignition Facility

    Science.gov (United States)

    Meezan, N. B.; Edwards, M. J.; Hurricane, O. A.; Patel, P. K.; Callahan, D. A.; Hsing, W. W.; Town, R. P. J.; Albert, F.; Amendt, P. A.; Berzak Hopkins, L. F.; Bradley, D. K.; Casey, D. T.; Clark, D. S.; Dewald, E. L.; Dittrich, T. R.; Divol, L.; Döppner, T.; Field, J. E.; Haan, S. W.; Hall, G. N.; Hammel, B. A.; Hinkel, D. E.; Ho, D. D.; Hohenberger, M.; Izumi, N.; Jones, O. S.; Khan, S. F.; Kline, J. L.; Kritcher, A. L.; Landen, O. L.; LePape, S.; Ma, T.; MacKinnon, A. J.; MacPhee, A. G.; Masse, L.; Milovich, J. L.; Nikroo, A.; Pak, A.; Park, H.-S.; Peterson, J. L.; Robey, H. F.; Ross, J. S.; Salmonson, J. D.; Smalyuk, V. A.; Spears, B. K.; Stadermann, M.; Suter, L. J.; Thomas, C. A.; Tommasini, R.; Turnbull, D. P.; Weber, C. R.

    2017-01-01

    This paper reviews scientific results from the pursuit of indirect drive ignition on the National Ignition Facility (NIF) and describes the program’s forward looking research directions. In indirect drive on the NIF, laser beams heat an x-ray enclosure called a hohlraum that surrounds a spherical pellet. X-ray radiation ablates the surface of the pellet, imploding a thin shell of deuterium/tritium (DT) that must accelerate to high velocity (v  >  350 km s-1) and compress by a factor of several thousand. Since 2009, substantial progress has been made in understanding the major challenges to ignition: Rayleigh Taylor (RT) instability seeded by target imperfections; and low-mode asymmetries in the hohlraum x-ray drive, exacerbated by laser-plasma instabilities (LPI). Requirements on velocity, symmetry, and compression have been demonstrated separately on the NIF but have not been achieved simultaneously. We now know that the RT instability, seeded mainly by the capsule support tent, severely degraded DT implosions from 2009-2012. Experiments using a ‘high-foot’ drive with demonstrated lower RT growth improved the thermonuclear yield by a factor of 10, resulting in yield amplification due to alpha particle heating by more than a factor of 2. However, large time dependent drive asymmetry in the LPI-dominated hohlraums remains unchanged, preventing further improvements. High fidelity 3D hydrodynamic calculations explain these results. Future research efforts focus on improved capsule mounting techniques and on hohlraums with little LPI and controllable symmetry. In parallel, we are pursuing improvements to the basic physics models used in the design codes through focused physics experiments.

  4. Une combinatoire du récit médiéval

    OpenAIRE

    Demartini, Dominique

    2010-01-01

    Dans le Château des destins croisés d’Italo Calvino, des chevaliers se retrouvent à une table d’hôtes et au moment de conter leur aventure, la parole leur fait défaut. Ils ont alors recours à un jeu de tarot pour figurer leur récit, et de carte en carte, chacun donne à deviner, à lire, sa propre histoire. Le tarot fonctionne ainsi, selon l’expression de Calvino, comme une « machine narrative combinatoire ». Si le tarot Visconti, avec ses enluminures du Quattrocento, sert de base à ce premier ...

  5. 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...

  6. Local Ignition in Carbon/Oxygen White Dwarfs -- I: One-zone Ignition and Spherical Shock Ignition of Detonations

    CERN Document Server

    Dursi, L J

    2006-01-01

    The details of ignition of Type Ia supernovae remain fuzzy, despite the importance of this input for any large-scale model of the final explosion. Here, we begin a process of understanding the ignition of these hotspots by examining the burning of one zone of material, and then investigate the ignition of a detonation due to rapid heating at single point. We numerically measure the ignition delay time for onset of burning in mixtures of degenerate material and provide fitting formula for conditions of relevance in the Type Ia problem. Using the neon abundance as a proxy for the white dwarf metallicity, we then find that ignition times can decrease by ~20% with addition of even 5% of neon by mass. When temperature fluctuations that successfully kindle a region are very rare, such a reduction in ignition time can increase the probability of ignition by orders of magnitude. We then consider the ignition of a detonation by an explosive energy input in one localized zone, eg a Sedov blast wave leading to a shock-i...

  7. On Compact Graphs

    Institute of Scientific and Technical Information of China (English)

    Ping WANG; Jiong Sheng LI

    2005-01-01

    Let G be a finite simple graph with adjacency matrix A, and let P(A) be the convex closure of the set of all permutation matrices commuting with A. G is said to be compact if every doubly stochastic matrix which commutes with A is in P(A). In this paper, we characterize 3-regular compact graphs and prove that if G is a connected regular compact graph, G - v is also compact, and give a family of almost regular compact connected graphs.

  8. "Jeunes de cités": Délinquance, émeutes et radicalisation islamiste

    Directory of Open Access Journals (Sweden)

    Gérard Mauger

    Full Text Available Résumé Pour rendre compte sociologiquement de l'ancrage de la délinquance, des violences urbaines et de la radicalisation islamiste dans une fraction des jeunes de cités, on étudie d'abord la crise de reproduction des classes populaires associée aux transformations du marché du travail, du système scolaire, de l'espace résidentiel, de l'encadrement des jeunes de cités, puis, en resserrant la focale de l'observation, la sociogenèse de la culture de rue (des héritages du pauvre à l'échec scolaire, l'investissement dans la culture de rue et l'inemployabilité, pour se focaliser enfin sur le monde des bandes et le milieu de la délinquance professionnelle, les pratiques émeutières et le revival des pratiques religieuses.

  9. 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.

  10. 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...

  11. 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

  12. 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

  13. Heat transfer characteristics of igniter output plumes

    Science.gov (United States)

    Evans, N. A.; Durand, N. A.

    Seven types of pyrotechnic igniters were each mounted at one end of a closed cylindrical bore hole representative of the center hole in a thermal battery. Measurements of local bore wall temperature, T(sub w), using commercially available, fast response (10 microsec) sheathed chromel-constantan thermocouples allowed calculation of local heat transfer rates, q, and wall heat flows, Q. The principal charge constituents of all these igniters were titanium and potassium perchlorate, while three types also contained barium styphnate as an ignition sensitizer. Igniter closure disc materials included glass-ceramic, glass, metal (plain, scored, with and without capture cone), and kapton/RTV. All igniters produced the lowest values of T(sub w) and q at the beginning of the bore, and, except for the igniter with the kapton/RTV closure disc, these quantities increased with distance along the bore. For igniters containing only titanium/potassium perchlorate, the rates of increase of Q along the bore length, compared with those for T(sub w) and q, were generally lower and more variable. The inclusion of barium styphnate produced rates of change in Q that were essentially constant to the end of the bore. The highest overall average wall temperatures were achieved by two igniter types with metal closure discs and no capture cone. No clear correlation was established between peak bore pressure and maximum wall temperature.

  14. Heat transfer characteristics of igniter output plumes

    Energy Technology Data Exchange (ETDEWEB)

    Evans, N.A.; Durand, N.A.

    1989-01-01

    Seven types of pyrotechnic igniters were each mounted at one end of a closed cylindrical bore hole representative of the center hole in a thermal battery. Measurements of local bore wall temperature, T/sub w/, using commercially available, fast response (10 /mu/sec) sheathed chromel-constantan thermocouples allowed calculation of local heat transfer rates, q, and wall heat flows, Q. The principal charge constituents of all these igniters were titanium and potassium perchlorate, while three types also contained barium styphnate as an ignition sensitizer. Igniter closure disc materials included glass-ceramic, glass, metal (plain, scored, with and without capture cone), and kapton/RTV. All igniters produced the lowest values of T/sub w/ and q at the beginning of the bore, and, except for the igniter with the kapton/RTV closure disc, these quantities increased with distance along the bore. For igniters containing only titanium/potassium perchlorate, the rates of increase of Q along the bore length, compared with those for T/sub w/ and q, were generally lower and more variable. The inclusion of barium styphnate produced rates of change in Q that were essentially constant to the end of the bore. The highest overall average wall temperatures were achieved by two igniter types with metal closure discs and no capture cone. No clear correlation was established between peak bore pressure and maximum wall temperature. 3 refs., 8 figs., 1 tab.

  15. Numerical simulation of spark ignition including ionization

    NARCIS (Netherlands)

    Thiele, M; Selle, S; Riedel, U; Warnatz, J; Maas, U

    2000-01-01

    A detailed understanding of the processes associated Midi spark ignition, as a first step during combustion, is of great importance fur clean operation of spark ignition engines. In the past 10 years. a growing concern for environmental protection, including low emission of pollutants, has increased

  16. Diplomatie universitaire ou diplomatie culturelle ? La Cité internationale universitaire de Paris entre deux rives (1920-1940)

    OpenAIRE

    Tronchet, Guillaume

    2013-01-01

    International audience; Il peut paraître tentant, au premier abord, de faire de la Cité internationale universitaire de Paris le fruit de cette diplomatie culturelle française mise en œuvre par les élites de la IIIe République au lendemain de la Grande Guerre. Les choses, nous semble-t-il, sont cependant plus complexes. Si la Cité internationale universitaire est bien partie prenante de ce processus, son histoire plonge ses racines dans un cadre moins connu ou, à tout le moins, guère théorisé...

  17. Genetic Organization of the citCDEF Locus and Identification of mae and clyR Genes from Leuconostoc mesenteroides

    OpenAIRE

    Bekal-Si Ali, Sadjia; Diviès, Charles; Prévost, Hervé

    1999-01-01

    In this paper, we describe two open reading frames coding for a NAD-dependent malic enzyme (mae) and a putative regulatory protein (clyR) found in the upstream region of citCDEFG of Leuconostoc mesenteroides subsp. cremoris 195. The transcriptional analysis of the citrate lyase locus revealed one polycistronic mRNA covering the mae and citCDEF genes. This transcript was detected only on RNA prepared from cells grown in the presence of citrate. Primer extension experiments suggest that clyR an...

  18. Isochoric Implosions for Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D S; Tabak, M

    2007-04-04

    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. & 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=cm{sup 3} and areal density of 2.4 g=cm{sup 2} using 485 kJ of laser energy.

  19. Theoretical study on ignition compensating temperature sensitivity

    Directory of Open Access Journals (Sweden)

    Mingfang Liu

    2015-09-01

    Full Text Available Temperature sensitivity of the propellant has significant influence on the interior ballistic performance of guns. Many physical and chemical approaches are employed to decrease this temperature sensitivity of the propellant. In this article, it is proposed that the temperature sensitivity of the propellant is changed by altering the factors required to ignition. A one-dimensional two-phase flow interior ballistic model is established to analyze the relation between ignition factors and temperature sensitivity. The simulation results show that the propellant temperature sensitivity is changed by altering the ignition factors. That is, the interior ballistic performance is affected by altering the size of fire hole, breaking liner pressure, and ignition location. Based on the simulation results, the temperature sensitivity can be controlled by matching of charges and intelligent control ignition system.

  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. 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.

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

    Science.gov (United States)

    Rygg, J. R.; Zylstra, A. B.; Séguin, F. H.; LePape, S.; Bachmann, B.; Craxton, R. S.; Garcia, E. M.; Kong, Y. Z.; Gatu-Johnson, M.; Khan, S. F.; Lahmann, B. J.; McKenty, P. W.; Petrasso, R. D.; Rinderknecht, H. G.; Rosenberg, M. J.; Sayre, D. B.; Sio, H. W.

    2015-11-01

    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 3He(d,p)4He nuclear reaction reveal a bright (1010 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)3He reactions also show 2 × 1010 isotropically distributed 3-MeV protons.

  3. Modeling the ignition of a copper oxide aluminum thermite

    Science.gov (United States)

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

    2017-01-01

    An experimental "striker confinement" shock compression experiment 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. Sample of materials such as a thermite mixture of copper oxide and aluminum powders are initially compressed to about 80 percent full density. Two RP-80 detonators simultaneously push steel bars into the 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 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 ignition of the copper oxide aluminum thermite in the context of the striker experiment and how a Gibbs formulation model [1], 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.

  4. 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.

  5. Serotonin transporters in Parkinson's disease studied with [I-123]{beta}-CIT SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Eun; Choi, Joon Young; Choe, Yearn Seong; Lee, Won Yong; Choi, Yong; Lee, Kyung Han; Kim, Byung Tae [Samsung Medical Center, Seoul (Korea, Republic of)

    1997-07-01

    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]{beta}-CIT (2{beta}-carbomethoxy-3{beta}-(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]{beta}-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] {beta}-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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lundkvist, Camilla; Halldin, Christer; Swahn, Carl-Gunnar; Hall, Haakan; Karlsson, Per; Nakashima, Yoshifumi; Wang, Shaoyin; Milius, Richard A.; Neumeyer, John L.; Farde, Lars

    1995-10-01

    {beta}-CIT-FP [N-(3-fluoropropyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane] is a cocaine analogue with a high affinity for the dopamine transporter. [O-methyl-{sup 11}C]{beta}-CIT-FP ([{sup 11}C]{beta}-CIT-FP) was prepared byO -alkylation of the free acid with [{sup 11}C]methyl iodide. The total radiochemical yield of [{sup 11}C]{beta}-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/{mu}mol (1000 Ci/mmol). Autoradiographic examination of [{sup 11}C]{beta}-CIT-FP binding in human brain postmortem demonstrated specific binding in the caudate nucleus and putamen. Positron emission tomography (PET) examination of [{sup 11}C]{beta}-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 {beta}-CIT, indicating that striatal radioactivity following injection of [{sup 11}C]{beta}-CIT-FP is associated with dopamine transporter sites and that the binding is reversible. The fraction of the total radioactivity in plasma representing [{sup 11}C]{beta}-CIT-FP determined by high-performance liquid chromatography (HPLC) was 84% at 15 min and 50% at 95 min. [{sup 11}C]{beta}-CIT-FP should be a useful PET radioligand for the quantitation of dopamine transporters in the human brain in vivo.

  7. Compaction behavior of isomalt after roll compaction.

    Science.gov (United States)

    Quodbach, Julian; Mosig, Johanna; Kleinebudde, Peter

    2012-09-27

    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist.

  8. Compaction Behavior of Isomalt after Roll Compaction

    Directory of Open Access Journals (Sweden)

    Peter Kleinebudde

    2012-09-01

    Full Text Available The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist.

  9. 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.

  10. Global reaction mechanism for the auto-ignition of full boiling range gasoline and kerosene fuels

    Science.gov (United States)

    Vandersickel, A.; Wright, Y. M.; Boulouchos, K.

    2013-12-01

    Compact reaction schemes capable of predicting auto-ignition are a prerequisite for the development of strategies to control and optimise homogeneous charge compression ignition (HCCI) engines. In particular for full boiling range fuels exhibiting two stage ignition a tremendous demand exists in the engine development community. The present paper therefore meticulously assesses a previous 7-step reaction scheme developed to predict auto-ignition for four hydrocarbon blends and proposes an important extension of the model constant optimisation procedure, allowing for the model to capture not only ignition delays, but also the evolutions of representative intermediates and heat release rates for a variety of full boiling range fuels. Additionally, an extensive validation of the later evolutions by means of various detailed n-heptane reaction mechanisms from literature has been presented; both for perfectly homogeneous, as well as non-premixed/stratified HCCI conditions. Finally, the models potential to simulate the auto-ignition of various full boiling range fuels is demonstrated by means of experimental shock tube data for six strongly differing fuels, containing e.g. up to 46.7% cyclo-alkanes, 20% napthalenes or complex branched aromatics such as methyl- or ethyl-napthalene. The good predictive capability observed for each of the validation cases as well as the successful parameterisation for each of the six fuels, indicate that the model could, in principle, be applied to any hydrocarbon fuel, providing suitable adjustments to the model parameters are carried out. Combined with the optimisation strategy presented, the model therefore constitutes a major step towards the inclusion of real fuel kinetics into full scale HCCI engine simulations.

  11. Modelling piloted ignition of wood and plastics.

    Science.gov (United States)

    van Blijderveen, Maarten; Bramer, Eddy A; Brem, Gerrit

    2012-09-01

    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 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.

  12. 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.

  13. Compact Polarimetry Potentials

    Science.gov (United States)

    Truong-Loi, My-Linh; Dubois-Fernandez, Pascale; Pottier, Eric

    2011-01-01

    The goal of this study is to show the potential of a compact-pol SAR system for vegetation applications. Compact-pol concept has been suggested to minimize the system design while maximize the information and is declined as the ?/4, ?/2 and hybrid modes. In this paper, the applications such as biomass and vegetation height estimates are first presented, then, the equivalence between compact-pol data simulated from full-pol data and compact-pol data processed from raw data as such is shown. Finally, a calibration procedure using external targets is proposed.

  14. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  15. Mechanics of tissue compaction.

    Science.gov (United States)

    Turlier, Hervé; Maître, Jean-Léon

    2015-12-01

    During embryonic development, tissues deform by a succession and combination of morphogenetic processes. Tissue compaction is the morphogenetic process by which a tissue adopts a tighter structure. Recent studies characterized the respective roles of cells' adhesive and contractile properties in tissue compaction. In this review, we formalize the mechanical and molecular principles of tissue compaction and we analyze through the prism of this framework several morphogenetic events: the compaction of the early mouse embryo, the formation of the fly retina, the segmentation of somites and the separation of germ layers during gastrulation.

  16. 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...

  17. 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

  18. 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...

  19. 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.

  20. cits de voyage, fiction et voyageurs fictifs dans American Notes de Charles Dickens

    Directory of Open Access Journals (Sweden)

    Nathalie VANFASSE

    2005-06-01

    Full Text Available Dickens effectua sa première visite aux Etats-Unis de janvier à juin 1842. Ce séjour inclut un mois au Canada. À la suite de ce voyage, le romancier publia American Notes qui parurent la même année. Dans son ouvrage intitulé Innocent Abroad : Charles Dickens’s American Engagements (1990, Jerome Meckier énumère les récits de voyage consacrés aux Etats-Unis que Dickens est supposé avoir consultés ou lus avant son propre périple : Diary in America (1839 du Capitaine Frederick Marryat, Observat...

  1. 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.

  2. 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.

  3. 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.

  4. Pharmacological studies of dopamine transporter imaging agent 125/131I-β-CIT

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To prepare 125/131I-β-CIT (2β-carbomethoxy-3β- (4-iodophenyl)tropane)as an imaging agent for dopamine transporter (DAT), the labeling method from tributylstannyl precursor with peracetic acid has been reported in this article. The radiochemical purity (RCP) of the labeled compound was over 95% determined by HPLC and TLC. The stability, partition coefficients were also determined. The pharmacological studies of the imaging agent were performed in rats, mice, rabbits and normal monkey. The ligand showed preferable uptake in brain (1.9%ID/organ in rats and 4.5%ID/organ in mice at 5 min). The ratios of striatum/cerebellum, hippocampus/cerebellum and cortex/cerebellum were 28.9, 3.97 and 4.75 at 6h in rats, and 8.52, 2.99 and 3.06 at 6h in mice, respectively. In monkey brain imaging the ratios of striatum/frontal cortex (ST/FC) and striatum/occipital cortex (ST/OC) were 5.14 and 5.97 at 4h, respectively. All of above showed the high affinity of the ligand to DAT. The compound was primarily metabolized in liver because the hepatic uptake was much higher than other organs (75.4%ID/organ at 18 h). The half-life of blood elimination was 5 min. The dose received by mice was 2500 times as high as that received by human in the test of undue toxicity, which evaluated the safety of the agent. All the results suggest that β-CIT can be used as a potential DAT imaging agent.

  5. Quand le terrain s’impose, le récit aussi

    Directory of Open Access Journals (Sweden)

    Nicolas Journet

    2009-03-01

    Full Text Available Quand le terrain s’impose, le récit aussi. L’exposé synoptique qui, selon Johannes Fabian, caractérise le genre anthropologique savant et marque ses limites laisse, en fait, parfois la place à des épisodes narratifs. Sur la base de quelques exemples, on suggère que ces récits semblent intervenir lorsque l’auteur veut restituer le mouvement par lequel il a été amené à changer d’idées ou de projets par l’évidence que lui impose le terrain. Et souvent aussi, cette articulation est déterminante pour l’orientation de l’écrit proposé. Ce n’est donc pas seulement un procédé rhétorique, mais une forme qui s’impose d’elle-même.When the field imposes itself, so does the narrative. The synoptic account which, according to Johannes Fabian, characterises the learned anthropological genre and its limitations actually leaves room, on occasion, for narrative episodes. Drawing on a number of examples, this article suggests that these narratives appear to occur when the author wishes to reconstruct the movement through which he was led to change his views or projects because of evidence imposed on him by the field. And often, this link is decisive in determining the orientation of the writing. It is therefore more than just a rhetorical procedure, but a form that imposes itself.

  6. Development status of the ignition system for Vinci

    NARCIS (Netherlands)

    Frenken, G.; Vermeulen, E.; Bouquet, F.; Sanders, H.M.

    2002-01-01

    The development status of ignition system for the new cryogenic upper stage engine Vinci is presented. The concept differs from existing upper stage ignition systems as its functioning is engine independent. The system consists of a spark torch igniter, a highpressure igniter feed system and an exci

  7. Compaction properties of isomalt

    NARCIS (Netherlands)

    Bolhuis, Gerad K.; Engelhart, Jeffrey J. P.; Eissens, Anko C.

    2009-01-01

    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of ispoma

  8. Helium Ignition on Accreting Neutron Stars with a New Triple-alpha Reaction Rate

    CERN Document Server

    Peng, Fang

    2010-01-01

    We investigate the effect of a new triple-alpha reaction rate from Ogata et al. (2009) on helium ignition conditions on accreting neutron stars and on the properties of the subsequent type I X-ray burst. We find that the new rate leads to significantly lower ignition column density for accreting neutron stars at low accretion rates. We compare the results of our ignition models for a pure helium accretor to observations of bursts in ultra-compact X-ray binary (UCXBs), which are believed to have nearly pure helium donors. For mdot > 0.001 mdot_Edd, the new triple-alpha reaction rate from Ogata et al. (2009) predicts a maximum helium ignition column of ~ 3 x 10^9 g cm^{-2}, corresponding to a burst energy of ~ 4 x 10^{40} ergs. For mdot ~ 0.01 mdot_Edd at which intermediate long bursts occur, the predicted burst energies are at least a factor of 10 too low to explain the observed energies of such bursts in UCXBs. This finding adds to the doubts cast on the triple-alpha reaction rate of Ogata et al. (2009) by th...

  9. Experiments and simulations on non-plasma ignition of semiconductor bridge igniter

    Science.gov (United States)

    Du, Weiqiang; Zhou, Bin; Liu, Jupeng; Li, Yong; Wang, Jun

    2017-01-01

    Since semiconductor bridge (SCB) igniter has been invented, it is commonly considered as a plasma generator. However, the plasma ignition mechanism may be affected by the hotspot ignition temperature of the primary explosives that is lower than the melting point of SCB in the igniter. In an effort to investigate the non-plasma ignition performance of SCB igniter, a one-dimensional model was established for temperature distribution analysis under constant current and capacitor discharge excitation. The simulation results featured the progress of heat transfer and the energy level required by non-plasma ignition of SCB was estimated. Furthermore, sensitivity experiments were carried out to test simulation results and to obtain the firing current range of SCB igniter with lead styphnate (LTNR). Experiment results indicated that safety conditions are 1.953 A constant current input lasting 1 ms under constant current excitation and 7.072 V voltage input using 47 µF storage capacitor under capacitor discharge excitation. All-firing conditions of non-plasma ignition are 2.035 A constant current input lasting 1 ms under constant current excitation and 7.647 V voltage input using 47 µF storage capacitor under capacitor discharge excitation.

  10. In ACPA-positive RA patients, antibodies to EBNA35-58Cit, a citrullinated peptide from the Epstein-Barr nuclear antigen-1, strongly cross-react with the peptide β60-74Cit which bears the immunodominant epitope of citrullinated fibrin.

    Science.gov (United States)

    Cornillet, M; Verrouil, E; Cantagrel, A; Serre, G; Nogueira, L

    2015-02-01

    Although several infectious agents and particularly Epstein-Barr virus (EBV) have been suspected to be involved in aetiology of rheumatoid arthritis (RA), their role still remains elusive. Almost 80% of RA sera contain antibodies to citrullinated proteins/peptides. Among them, the autoantibodies to citrullinated human fibrinogen (AhFibA) are composed of two non-cross-reactive subsets directed to immunodominant epitopes borne by the α36-50Cit and β60-74Cit fibrin peptides. RA sera also contain antibodies towards the citrullinated EBNA35-58Cit peptide derived from the EBNA-1 protein of EBV. Here, using a large cohort of RA patients and controls, we showed that for a diagnostic specificity of 98.5%, 47% of the AhFibA-positive patients were anti-EBNA35-58Cit-positive and that almost all (98.5%) the anti-EBNA35-58Cit-positive were AhFibA-positive, whereas 86% were anti-β60-74Cit-positive and only 43% anti-α36-50Cit-positive. AhFibA, anti-EBNA35-58Cit- and anti-β60-74Cit-antibody titres were significantly correlated. Competition assays showed that anti-EBNA35-58Cit antibodies are highly cross-reactive with the β60-74Cit peptide. The demonstration that a citrullinated peptide derived from the EBNA-1 protein of EBV presents a molecular mimicry with human citrullinated fibrin constitutes an additional argument for a possible role of EBV in RA aetiopathogeny.

  11. Initial Testing of a Prototype Laser Ignition Chamber

    Science.gov (United States)

    2014-03-01

    investigated for the ignition of many energetic materials, including igniter materials such as black powder, nitrocellulose , M44 propellant (44...nitroglycerin, 52% nitrocellulose ), and numerous other propellants (11–34). Lasers used for these studies included Nd:glass lasers (up to 30 J at 1.054...It was observed that some propellants which do not ignite in air with certain lasers were effectively ignited when enclosed in a laser ignition

  12. 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.

  13. Compaction properties of isomalt.

    Science.gov (United States)

    Bolhuis, Gerad K; Engelhart, Jeffrey J P; Eissens, Anko C

    2009-08-01

    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of ispomalt were studied. The types used were the standard product sieved isomalt, milled isomalt and two types of agglomerated isomalt with a different ratio between 6-O-alpha-d-glucopyranosyl-d-sorbitol (GPS) and 1-O-alpha-d-glucopyranosyl-d-mannitol dihydrate (GPM). Powder flow properties, specific surface area and densities of the different types were investigated. Compactibility was investigated by compression of the tablets on a compaction simulator, simulating the compression on high-speed tabletting machines. Lubricant sensitivity was measured by compressing unlubricated tablets and tablets lubricated with 1% magnesium stearate on an instrumented hydraulic press. Sieved isomalt had excellent flow properties but the compactibility was found to be poor whereas the lubricant sensitivity was high. Milling resulted in both a strong increase in compactibility as an effect of the higher surface area for bonding and a decrease in lubricant sensitivity as an effect of the higher surface area to be coated with magnesium stearate. However, the flow properties of milled isomalt were too bad for use as filler-binder in direct compaction. Just as could be expected, agglomeration of milled isomalt by fluid bed agglomeration improved flowability. The good compaction properties and the low lubricant sensitivity were maintained. This effect is caused by an early fragmentation of the agglomerated material during the compaction process, producing clean, lubricant-free particles and a high surface for bonding. The different GPS/GPM ratios of the agglomerated isomalt types studied had no significant effect on the compaction properties.

  14. 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.

  15. Ignition of Propellants Through Nanostructured Materials

    Science.gov (United States)

    2016-03-31

    case gaseous O2 was introduced in a coaxial flow at a rate of 7 Lit/min with a swirl motion in order to produce an effective fuel and oxidizer mixing...system should be robust, efficient , reliable, simple, low cost, and flexible. Also, an ignition system should initiate combustion under a broad range...discovered that the SWCNT material does not ignite well if wet, so we encapsulated the material to protect it from the fuel spray. To improve the

  16. IGNITION ACTIVATION ENERGY OF MATERIALS BASED

    OpenAIRE

    Peter RANTUCH; Igor WACHTER; Ivan HRUŠOVSKÝ; Balog, Karol

    2016-01-01

    This contribution is aimed to compare the values of the ignition activation energies of two types of polyamide – Slovamid 6 FRB and Slovamid GF 50 LTS. Samples were isothermally stressed at five different temperatures between 500 °C a 550 °C, while the time to initiation of the flame combustion was monitored. Subsequently from the measured times were compiled Arrhenius plots under which activation energy of ignition of both polymers were calculated. The values of activation energies were 106 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Eshuis, S.A. [University Hospital Groningen, Department of Neurology, Groningen (Netherlands); University Hospital Groningen, Department of Nuclear Medicine, Groningen (Netherlands); Maguire, R.P.; Leenders, K.L. [University Hospital Groningen, Department of Neurology, Groningen (Netherlands); Jonkman, S.; Jager, P.L. [University Hospital Groningen, Department of Nuclear Medicine, Groningen (Netherlands)

    2006-02-01

    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 ({rho}=-0.52 for both techniques), UPDRS-III ({rho}=-0.38 for F-DOPA; {rho}=-0.45 for FP-CIT) and disease duration ({rho}=-0.59 for F-DOPA; {rho}=-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.)

  18. Spark Ignition of Monodisperse Fuel Sprays. Ph.D. Thesis

    Science.gov (United States)

    Danis, Allen M.; Cernansky, Nicholas P.; Namer, Izak

    1987-01-01

    A study of spark ignition energy requirements was conducted with a monodisperse spray system allowing independent control of droplet size, equivalent ratio, and fuel type. Minimum ignition energies were measured for n-heptane and methanol sprays characterized at the spark gap in terms of droplet diameter, equivalence ratio (number density) and extent of prevaporization. In addition to sprays, minimum ignition energies were measured for completely prevaporized mixtures of the same fuels over a range of equivalence ratios to provide data at the lower limit of droplet size. Results showed that spray ignition was enhanced with decreasing droplet size and increasing equivalence ratio over the ranges of the parameters studied. By comparing spray and prevaporized ignition results, the existence of an optimum droplet size for ignition was indicated for both fuels. Fuel volatility was seen to be a critical factor in spray ignition. The spray ignition results were analyzed using two different empirical ignition models for quiescent mixtures. Both models accurately predicted the experimental ignition energies for the majority of the spray conditions. Spray ignition was observed to be probabilistic in nature, and ignition was quantified in terms of an ignition frequency for a given spark energy. A model was developed to predict ignition frequencies based on the variation in spark energy and equivalence ratio in the spark gap. The resulting ignition frequency simulations were nearly identical to the experimentally observed values.

  19. EXPERIMENTAL STUDY OF MINIMUM IGNITION TEMPERATURE

    Directory of Open Access Journals (Sweden)

    Igor WACHTER

    2015-12-01

    Full Text Available 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 determine the minimum temperature at which ignition or decomposition of dust occurs during thermal straining on a hot plate at a constant temperature. The highest minimum smouldering and carbonating temperature of spent coffee grounds for 5 mm high layer was determined at the interval from 280 °C to 310 °C during 600 seconds. Method B is used to determine the minimum ignition temperature of a dust cloud. Minimum ignition temperature of studied dust was determined to 470 °C (air pressure – 50 kPa, sample weight 0.3 g.

  20. 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.

  1. Comparable investigation in dopamine transporters with 99mTc-TRODAT-1 and 131I-FP-CIT SPECT in Parkinson's disease patients

    Institute of Scientific and Technical Information of China (English)

    LIU Congjin; LIU Xingdang; ZHANG Guangming; LI Ding; WANG Jian; YANG Liqin; JIANG Yuping

    2007-01-01

    Dopamine transporter (DAT) mediates the regulation of dopaminergic function. Two agents of TRODAT-1and FP-CIT were observed in evaluating DAT change of Parkinson's disease (PD). The relationship between them was also evaluated. The results suggested that 99mTc-TRODAT-1 SPECT and 131I-FP-CIT SPECT may serve as sensitiveand objective in vivo markers to reflect the severity of PD. The 99mTc-TRODAT-1 image is more accurate and clearercompared with 131I-FP-CIT.

  2. 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.

  3. Structure Analysis of Oxidation Film of Ignition-Inhibition AZ91D Ma gnesium Alloy Added with Cerium

    Institute of Scientific and Technical Information of China (English)

    黄晓锋; 周宏; 何镇明

    2003-01-01

    The effect of cerium on ignition temperature of AZ91D magnesium alloy was studied. By the addition of cerium of 1%, the ignition temperature is raised by 180 ℃, so the magnesium alloy added with cerium can be melted in air. The burning temperature increases with the increasing of cerium. The structure and chemical compositions of the surface oxide film were investigated by XRD and Auger electron spectrometry(AES). The results of XRD indicate that the oxide film of the surface of ignition-inhibition magnesium alloy can change from loose structure of simple magnesia to compact composite structure consisting of magnesia, cerium oxide, Mg17 A112 and aluminum oxide, which has excellent ignition-inhibition effect. AES depth profile analysis shows that the oxide film can be divided into three layers. The outside layer is mainly made up of magnesia, the middle layer, which consists of cerium oxide, magnesia, and aluminum oxide, is compound and compact. Thermodynamic analysis indicates that the structure of the surface oxide film is accordant to the change of free energy and high vapor pressure of magnesium.

  4. Small Valdivia compact spaces

    CERN Document Server

    Kubi's, W; Kubi\\'s, Wieslaw; Michalewski, Henryk

    2005-01-01

    We prove a preservation theorem for the class of Valdivia compact spaces, which involves inverse sequences of ``simple'' retractions. Consequently, a compact space of weight $\\loe\\aleph_1$ is Valdivia compact iff it is the limit of an inverse sequence of metric compacta whose bonding maps are retractions. As a corollary, we show that the class of Valdivia compacta of weight at most $\\aleph_1$ is preserved both under retractions and under open 0-dimensional images. Finally, we characterize the class of all Valdivia compacta in the language of category theory, which implies that this class is preserved under all continuous weight preserving functors.

  5. 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

  6. Shock-Ignited High Gain/Yield Targets for the National Ignition Facility

    Science.gov (United States)

    Perkins, L. J.; Lafortune, K. N.; Bedrosiian, P.; Tabak, M.; Miles, A.; Dixit, S.; Betti, R.; Anderson, K.; Zhou, C.

    2006-10-01

    Shock-ignition, a new concept for ICF ignition [C.Zhou, R.Betti Bull APS, v50, 2005], is being studied as a future option for efficiently achieving high gains in large laser facilities such as NIF. Accordingly, this offers the potential for testing: (1)High yield (up to 200MJ), reactor-relevant targets for inertial fusion energy (2)High fusion yield targets for DOE NNSA stockpile application (3)Targets with appreciable gain at low laser drive energies (gains of 10's at 150kJ) (4)Ignition of simple, non-cryo (room temperature) single shell gas targets at (unity gain). By contrast to conventional hotspot ignition, we separate the assembly and ignition phases by initially imploding a massive cryogenic shell on a low adiabat (alpha 0.7) at low velocity (less than 2e7cm/s) using a direct drive pulse of modest total energy. The assembled fuel is then separately ignited by a strong, spherically convergent shock driven by a high intensity spike at the end of the pulse and timed to reach the center as the main fuel is stagnating and starting to rebound. Like fast ignition, shock ignition can achieve high gains with low drive energy, but has the advantages of requiring only a single laser with less demanding timing and spatial focusing requirements.

  7. Shock ignition: an alternative scheme for HiPER

    Science.gov (United States)

    Ribeyre, X.; Schurtz, G.; Lafon, M.; Galera, S.; Weber, S.

    2009-01-01

    Two main paths are now under investigation that aim at thermonuclear ignition of hydrogen isotopes using lasers: central hot spot self-ignition and externally driven fast ignition of preassembled fuel. A third, intermediate, scheme is shock ignition, which combines the simplicity of self-ignition capsules to the hydrodynamic robustness of the fast ignition fuel assembly. This study addresses the potential of shock ignition for the HiPER project and provides a preliminary assessment of possible detrimental effects. Monodimensional simulations are performed to study the robustness of the ignition scheme in terms of shock launching time and laser power. Bidimensional simulations address the sensitivity of shock ignition to irradiation nonuniformity and to low mode asymmetries of the fuel assembly.

  8. 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.

  9. « 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.

  10. 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.

  11. Compact microchannel system

    Science.gov (United States)

    Griffiths, Stewart

    2003-09-30

    The present invention provides compact geometries for the layout of microchannel columns through the use of turns and straight channel segments. These compact geometries permit the use of long separation or reaction columns on a small microchannel substrate or, equivalently, permit columns of a fixed length to occupy a smaller substrate area. The new geometries are based in part on mathematical analyses that provide the minimum turn radius for which column performance in not degraded. In particular, we find that straight channel segments of sufficient length reduce the required minimum turn radius, enabling compact channel layout when turns and straight segments are combined. The compact geometries are obtained by using turns and straight segments in overlapped or nested arrangements to form pleated or coiled columns.

  12. 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...

  13. 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...

  14. 3rd Conference on Ignition Systems for Gasoline Engines

    CERN Document Server

    Sens, Marc

    2017-01-01

    The volume includes selected and reviewed papers from the 3rd Conference on Ignition Systems for Gasoline Engines in Berlin in November 2016. Experts from industry and universities discuss in their papers the challenges to ignition systems in providing reliable, precise ignition in the light of a wide spread in mixture quality, high exhaust gas recirculation rates and high cylinder pressures. Classic spark plug ignition as well as alternative ignition systems are assessed, the ignition system being one of the key technologies to further optimizing the gasoline engine.

  15. 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.

  16. Increased brain temserotoneric transporter availability in adult migraineurs: ([18F]FP-CIT PET imaging pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun Kyung [Dept. of Nuclear Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Hwang, Yu Mi [Center for Research Information, Korea University, Seoul (Korea, Republic of); Chu, Min Kyung [Dept. of Neurology, Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of); Jung, Ki Young [Dept. of Neurology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-03-15

    Recent studies have proposed central serotonergic dysfunction as a major pathophysiology of migraine. We investigated serotonin transporter (SERT) availability in migraineurs using F-18-N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl) nortropane ([18F]FP-CIT) positron emission tomography (PET). Brain [18F]FP-CIT PET images were obtained in eight women with migraine during headache free phase and 12 healthy adult women, 120 min after injection of 185 MBq. Non-displaceable binding potential (BP ND) of [18F]FP-CIT, which is an estimate of SERT availability, was calculated at the brainstem and compared with clinical parameters. BP ND at the brainstem was significantly higher in adult migraineurs (n = 6, 1.15 ± 0.17) than healthy subjects (0.95 ± 0.14) (p = 0.04). Healthy subjects demonstrated negative correlation between brainstem BP ND and age (r = −0.64, p = 0.02), whereas this age-related decline pattern was not found in the migraineurs. Severity of migraine attack was significantly correlated with brainstem BP ND (r = 0.66, p = 0.02), when age and duration of illness were corrected. Increased SERT availability in the brainstem of adult migraineurs indicates low serotonin neurotransmission during headache-free phase. Patients who experience more painful headaches have lower serotonin neurotransmission. [18F]FP-CIT PET is a useful in vivo imaging technique for evaluating brainstem SERT availability in migraineurs.

  17. Dark Matter Ignition of Type Ia Supernovae.

    Science.gov (United States)

    Bramante, Joseph

    2015-10-02

    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.

  18. Effekte einer Langzeit-Therapie mit Pramipexol oder Levodopa auf die [123I]FP-CIT SPECT in einem Mausmodell der Parkinson-Krankheit

    OpenAIRE

    Maurer, Lukas

    2015-01-01

    Die zuvor durchgeführte klinische Studie CALM-PD (ParkinsonStudyGroup, 2002) untersuchte den Effekt einer Langzeittherapie mit Levodopa oder Pramipexol auf das Fortschreiten der Parkinson-Krankheit mittels SPECT unter Verwendung des Dopamintransporter-Liganden [123I]β-CIT als Surrogat-Marker. Die [123I]β-CIT Bindung fiel in den Patienten, die Levodopa erhalten hatten, auf ein signifikant niedrigeres Niveau ab, als bei den Patiente...

  19. 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.

  20. Les didascalies de l’énonciateur cité dans le journal Le Monde

    Directory of Open Access Journals (Sweden)

    Elżbieta Biardzka

    2012-12-01

    Full Text Available This paper deals with the visual, vocal and emotional portraits of the quoted speakers (énonciateurs cités, EC as they are depicted by journalists in Le Monde. These portraits can be divided into two groups: in the first one, the speakers are presented without prosopography, and in the second, they emerge from the text throughprosopographic elements. The group of speakers without prosopographyis itself divided into two sub-groups: notorious speakers and visuallyanonymous speakers. In the prosopographically presented speakers’group, the reporter presents details of the physical appearance, butcan also describe his proxemic or vocal behaviour of the speaker, which can be near to the vocal ethos or remain at the level of vocal gesture. The speakers (and their speech are then depicted and classified: some seem to be more reliable and more famous than the others and then seem to have a certain level of power, some seem more trivial, or even more ridiculous and petty.

  1. 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...

  2. Genes associated with hypersensitive response (HR in the citrus EST database (CitEST

    Directory of Open Access Journals (Sweden)

    Simone Guidetti-Gonzalez

    2007-01-01

    Full Text Available Plants are continuously exposed to pathogen attack, but successful infection is rare because they protect themselves against pathogens using a wide range of response mechanisms. One of them is the hypersensitive response (HR, which is a form of cell death often associated with plant resistance to pathogen infection to prevent the spreadsebpg@cnpq.br sebpg@cnpq.br of the potential pathogen from infected to uninfected tissues. Cell death is activated by recognition of pathogen-derived molecules by the resistance (R gene products, and is associated with the massive accumulation of reactive oxygen species (ROS, salicylic acid (SA, and other pro-death signals such as nitric oxide (NO. The analysis of the citrus EST (CitEST database revealed the presence of putative genes likely to be involved in HR through their products, like metacaspases, lipoxygenases, phospholipases, pathogenesis-related proteins, glutathione transferases/peroxidases, enzymes involved in the phenylpropanoid pathway and in the formation and detoxification of ROS, as well as those involved in the formation and regulation of ion channels, SA and NO. By analysis of the EST database of Citrus, it was possible to identify several putative genes that code for key enzymes involved in HR triggering and also in plant defense against biotic and abiotic stress.

  3. 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...

  4. 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

  5. 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.

  6. Proteome from lemon fruit flavedo reveals that this tissue produces high amounts of the Cit s1 germin-like isoforms.

    Science.gov (United States)

    Pignataro, Vittorio; Canton, Cristina; Spadafora, Antonia; Mazzuca, Silvia

    2010-06-23

    A multistep procedure has been developed and applied to extract and purify proteins from lemon fruit flavedo. 2DE, LC-ESI-MS/MS, and bioinformatics were used to detect the high abundance of the germin-like glycoprotein Cit s1, a powerful allergen in humans. Peptide alignments against Citrus EST repositories gave the best scores with the C. sinensis cDNA (gi|188354270/EY710037), annotated as unknown sweet orange fruit protein; additional BLAST of peptides against NCBI databases gave high sequence identities with sequence of orange Cit s1 (gi|52782810/P84159), suggesting that the unknown sweet orange fruit protein is consistent with the Cit s1 protein. Peptides of Cit s1 were detected in 17 spots ranging from 120 to 20 kDa, pointing out that in the flavedo of lemon the Cit s1 may be expressed as several isoforms of which the 120 kDa isoform is the largest monomer and the 20 kDa is the smallest one. This finding adds information about the features of Cit s1, because it has been previously reported as a unique monomeric glycoprotein of 24 kDa.

  7. 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.

  8. 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.

  9. Ignition of THKP and TKP pyrotechnic powders :

    Energy Technology Data Exchange (ETDEWEB)

    Maharrey, Sean P.; Erikson, William W; Highley, Aaron M.; Wiese-Smith, Deneille; Kay, Jeffrey J

    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.

  10. 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...

  11. Ignition delay of dual fuel engine operating with methanol ignited by pilot diesel

    Institute of Scientific and Technical Information of China (English)

    Hongbo ZOU; Lijun WANG; Shenghua LIU; Yu LI

    2008-01-01

    An investigation on the ignition delay of a dual fuel engine operating with methanol ignited by pilot diesel was conducted on a TY1100 direct-injection diesel engine equipped with an electronic controlled methanol low-pressure injection system. The experimental results show that the polytropic index of compression process of the dual fuel engine decreases linearly while the ignition delay increases with the increase in methanol mass fraction. Compared with the conventional diesel engine, the igni-tion delay increment of the dual fuel engine is about 1.5° at a methanol mass fraction of 62%, an engine speed of 1600 r/min, and full engine load. With the elevation of the intake charge temperature from 20℃ to 40℃ and then to 60℃, the ignition delay of the dual fuel engine decreases and is more obvious at high temperature. Moreover, with the increase in engine speed, the ignition delay of the dual fuel engine by time scale (ms) decreases clearly under all engine operating conditions. However, the ignition delay of the dual fuel engine increases remark-ably by advancing the delivery timing of pilot diesel, espe-cially at light engine loads.

  12. 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

  13. Robustness studies of ignition targets for the National Ignition Facility in two dimensionsa)

    Science.gov (United States)

    Clark, Daniel S.; Haan, Steven W.; Salmonson, Jay D.

    2008-05-01

    Inertial confinement fusion capsules are critically dependent on the integrity of their hot spots to ignite. At the time of ignition, only a certain fractional perturbation of the nominally spherical hot spot boundary can be tolerated and the capsule still achieve ignition. The degree to which the expected hot spot perturbation in any given capsule design is less than this maximum tolerable perturbation is a measure of the ignition margin or robustness of that design. Moreover, since there will inevitably be uncertainties in the initial character and implosion dynamics of any given capsule, all of which can contribute to the eventual hot spot perturbation, quantifying the robustness of that capsule against a range of parameter variations is an important consideration in the capsule design. Here, the robustness of the 300eV indirect drive target design for the National Ignition Facility [Lindl et al., Phys. Plasmas 11, 339 (2004)] is studied in the parameter space of inner ice roughness, implosion velocity, and capsule scale. A suite of 2000 two-dimensional simulations, run with the radiation hydrodynamics code LASNEX, is used as the data base for the study. For each scale, an ignition region in the two remaining variables is identified and the ignition cliff is mapped. In accordance with the theoretical arguments of Levedahl and Lindl [Nucl. Fusion 37, 165 (1997)] and Kishony and Shvarts [Phys. Plasmas 8, 4925 (2001)], the location of this cliff is fitted to a power law of the capsule implosion velocity and scale. It is found that the cliff can be quite well represented in this power law form, and, using this scaling law, an assessment of the overall (one- and two-dimensional) ignition margin of the design can be made. The effect on the ignition margin of an increase or decrease in the density of the target fill gas is also assessed.

  14. Human biodistribution and dosimetry of [{sup 123}I]FP-CIT: a potent radioligand for imaging of dopamine transporters

    Energy Technology Data Exchange (ETDEWEB)

    Booij, J.; Busemann Sokole, E.; De Bruin, K.; Van Royen, E.A. [Graduate School of Neurosciences, Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Stabin, M.G. [Radiation Internal Dose Information Center, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee (United States); Janssen, A.G.M. [Amersham Cygne and Eindhoven University of Technology, Eindhoven (Netherlands)

    1998-01-01

    This study reports on the biodistribution and radiation dosimetry of iodine-123-labelled N-{omega}-(flu- oropropyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ([{sup 123}I]FP-CIT), a promising radioligand for the imaging of dopamine transporters. In 12 healthy volunteers, conjugate whole-body scans were performed up to 48 h following intravenous injection of approximately 100 MBq [{sup 123}I]FP-CIT. Attenuation correction was performed using a transmission whole-body scan obtained prior to injection of the radioligand, employing a {sup 123}I flood source. Blood samples were taken and urine was freely collected up to 48 h after injection of the radiotracer. For each subject, the percentage of injected activity measured in regions of interest over brain, striatum, lungs and liver were fitted to a multicompartmental model to give time-activity curves. The cumulative urine activity curve was used to model the urinary excretion rate and, indirectly, to predict faecal excretion. Using the MIRD method, nine source organs were considered in estimating absorbed radiation doses for organs of the body. The images showed rapid lung uptake and hepatobiliary excretion. Diffuse uptake and retention of activity was seen in the brain, especially in the striatum. At 48 h following the injection of [{sup 123}I]FP-CIT, mean measured urine excretion was 60%{+-}9% (SD), and mean predicted excretion in faeces was 14%{+-}1%. In general, the striatum received the highest absorbed dose (average 0.23 mGy/MBq), followed by the urinary bladder wall (average 0.054 mGy/MBq) and lungs (average 0.043 mGy/MBq). The average effective dose equivalent of [{sup 123}I]FP-CIT was estimated to be 0.024 mSv/MBq. The amount of [{sup 123}I]FP-CIT required for adequate dopamine transporter imaging results in an acceptable effective dose equivalent to the patient. (orig.) With 3 figs., 4 tabs., 39 refs.

  15. Low Energy Electronic Ignition System for NOFBX Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a miniature, low RF noise ignition module for NOFBX propulsion systems. This ignition module is designed utilizing unique properties of the...

  16. National Ignition Facility project acquisition plan revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Clobes, A.R.

    1996-10-01

    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.

  17. 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...

  18. Compactness theorems of fuzzy semantics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The relationship among diverse fuzzy semantics vs. the corresponding logic consequence operators has been analyzed systematically. The results that compactness and logical compactness of fuzzy semantics are equivalent to compactness and continuity of the logic consequence operator induced by the semantics respectively have been proved under certain conditions. A general compactness theorem of fuzzy semantics have been established which says that every fuzzy semantics defined on a free algebra with members corresponding to continuous functions is compact.

  19. Radiation Driven Capsules for Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, M; Slutz, S A

    2001-06-08

    The energy required to ignite compressed deuterium-tritium fuel is a strong function of the fuel density. Through a series of detailed numerical simulations, peak fuel densities have been calculated as a function of the peak radiation drive temperature. Note that the time dependence of the radiation temperature (pulse shaping) has been optimized to obtain maximum density for each scaling point. A simple analytic scaling is developed, which agrees well with the numerical results. These scaling results are then used to obtain the required ignition energy as a function of peak drive temperature.

  20. IGNITION ACTIVATION ENERGY OF MATERIALS BASED

    Directory of Open Access Journals (Sweden)

    Peter RANTUCH

    2016-06-01

    Full Text Available This contribution is aimed to compare the values of the ignition activation energies of two types of polyamide – Slovamid 6 FRB and Slovamid GF 50 LTS. Samples were isothermally stressed at five different temperatures between 500 °C a 550 °C, while the time to initiation of the flame combustion was monitored. Subsequently from the measured times were compiled Arrhenius plots under which activation energy of ignition of both polymers were calculated. The values of activation energies were 106 kJ.mol-1 and 158.0 kJ.mol-1 for Slovamid 6 FRB 4 and Slovamid 6 GF 50 LTS.

  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. Intelligent compaction theory of high roller compacted concrete dam

    Institute of Scientific and Technical Information of China (English)

    Liu Donghai

    2012-01-01

    The concept and realization process of intelligent compaction for the construction of high roller compacted concrete dam were presented, as well as the theory of monitoring and intelligent feedback control. Based on the real-time analysis of the compaction index, a multiple regression model of the dam compactness was established and a realime estimation method of compaction quality for the entire work area of roller compacted concrete dam was proposed finally. The adaptive adjustment of the roiling process parameters was achieved, with the speed, the exciting force, the roller pass and the compaction thickness meeting the standards during the whole construction process. As a result, the compaction quality and construction efficiency can be improved. The research provides a new way for the construction quality control of roller compacted concrete dam.

  3. Laser Ignition Technology for Bi-Propellant Rocket Engine Applications

    Science.gov (United States)

    Thomas, Matt; Bossard, John; Early, Jim; Trinh, Huu; Dennis, Jay; Turner, James (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of laser ignition technology for bipropellant rocket engines applications. The objectives of this project include: (1) the selection test chambers and flows; (2) definition of the laser ignition setup; (3) pulse format optimization; (4) fiber optic coupled laser ignition system analysis; and (5) chamber integration issues definition. The testing concludes that rocket combustion chamber laser ignition is imminent. Support technologies (multiplexing, window durability/cleaning, and fiber optic durability) are feasible.

  4. 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

  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. 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.

     

  7. Evolution of clinical features in possible DLB depending on FP-CIT SPECT result

    Science.gov (United States)

    Moreno, Emilio; Thomas, Alan; Inglis, Fraser; Tabet, Naji; Stevens, Tim; Whitfield, Tim; Aarsland, Dag; Rainer, Michael; Padovani, Alessandro

    2016-01-01

    Objective: To test the hypothesis that core and suggestive features in possible dementia with Lewy bodies (DLB) would vary in their ability to predict an abnormal dopamine transporter scan and therefore a follow-up diagnosis of probable DLB. A further objective was to assess the evolution of core and suggestive features in patients with possible DLB over time depending on the 123I-FP-CIT SPECT scan result. Methods: A total of 187 patients with possible DLB (dementia plus one core or one suggestive feature) were randomized to have dopamine transporter imaging or to follow-up without scan. DLB features were compared at baseline and at 6-month follow-up according to imaging results and follow-up diagnosis. Results: For the whole cohort, the baseline frequency of parkinsonism was 30%, fluctuations 29%, visual hallucinations 24%, and REM sleep behavior disorder 17%. Clinician-rated presence of parkinsonism at baseline was significantly (p = 0.001) more frequent and Unified Parkinson’s Disease Rating Scale (UPDRS) score at baseline was significantly higher (p = 0.02) in patients with abnormal imaging. There was a significant increase in UPDRS score in the abnormal scan group over time (p < 0.01). There was relatively little evolution of the rest of the DLB features regardless of the imaging result. Conclusions: In patients with possible DLB, apart from UPDRS score, there was no difference in the evolution of DLB clinical features over 6 months between cases with normal and abnormal imaging. Only parkinsonism and dopamine transporter imaging helped to differentiate DLB from non-DLB dementia. PMID:27511183

  8. Dark matter ignition of type Ia supernovae

    CERN Document Server

    Bramante, Joseph

    2015-01-01

    Recent studies of low redshift type Ia supernovae (SNIa) indicate that half explode from less than Chandrasekhar mass white dwarfs, implying ignition must proceed from something besides the canonical criticality of Chandrasekhar mass SNIa progenitors. We show that $0.1-10$ 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 SNIa. We combine data on SNIa masses with data on the ages of SNIa-adjacent stars. This combination reveals a $ 3 \\sigma$ inverse correlation between SNIa masses and ignition ages, which could result from increased capture of dark matter in 1.4 versus 1.1 solar mass white dwarfs. Future studies of SNIa in galactic centers will provide additional tests of dark-matter-induced type Ia ignition. Remarkably, both bosonic and fermionic SNI...

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. Compact rotating cup anemometer

    Science.gov (United States)

    Wellman, J. B.

    1968-01-01

    Compact, collapsible rotating cup anemometer is used in remote locations where portability and durability are factors in the choice of equipment. This lightweight instrument has a low wind-velocity threshold, is capable of withstanding large mechanical shocks while in its stowed configuration, and has fast response to wind fluctuations.

  14. 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.

  15. Ignition and Thermonuclear Burn on the National Ignition Facility with Imposed Magnetic Fields

    Science.gov (United States)

    Perkins, L. John; Logan, B. G.; Rhodes, M. A.; Zimmerman, G. B.; Ho, D. D.; Blackfield, D. T.; Hawkins, S. A.

    2016-10-01

    We are studying the impact of highly compressed magnetic fields on enhancing the prospects for ignition and burn on the National Ignition Facility (NIF). Both magnetized room-temperature DT gas targets and cryo-ignition capsules are under study. Applied seed fields of 20-70T that compress to greater than 10000T (100MG) under implosion can reduce hotspot conditions required for ignition and propagating burn through range reduction and magnetic mirror trapping of fusion alpha particles, suppression of electron heat conduction and potential stabilization of hydrodynamic instabilities. The applied field may also reduce hohlraum laser-plasma instabilities and suppress the transport of hot electron preheat to the capsule. These combined B-field attributes may permit recovery of ignition, or at least significant alpha particle heating, in capsules that are otherwise submarginal through adverse hydrodynamic or hohlraum-drive conditions. Simulations indicate that optimum initial fields of 50T may produce multi-MJ-yields when applied to our present best experimental capsules. Proof-of-principle experiments for magnetized ignition capsules and hohlraum physics on NIF are now being designed. This work performed under auspices of U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  16. Improving the compaction properties of roller compacted calcium carbonate.

    Science.gov (United States)

    Bacher, C; Olsen, P M; Bertelsen, P; Kristensen, J; Sonnergaard, J M

    2007-09-05

    The effects of roller compaction process parameters, morphological forms of calcium carbonate and particle size of sorbitol on flow, compaction and compression properties were investigated. The morphology of the calcium carbonate and the sorbitol particle size were more influential on the compaction properties than the settings of the roller compactor. The roller compaction process was demonstrated to be robust and stable in regard to flowability and compactibility. The flowability of the granules was improved adequately to facilitate compression in a production scale rotary tablet press. By adding sorbitol to the calcium carbonate, the compressibility - characterized by the Walker coefficient W(ID) - and the compactibility C(P) were improved considerably. A correlation between the consolidation characteristics was demonstrated. Compactibility data from the compaction simulator correlated with the tablet press for two of the calcium carbonates, the cubic form and the ground quality.

  17. 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

  18. Nuclear imaging of the fuel assembly in ignition experiments

    Energy Technology Data Exchange (ETDEWEB)

    Grim, G. P.; Guler, N.; Merrill, F. E.; Morgan, G. L.; Danly, C. R.; Volegov, P. L.; Wilde, C. H.; Wilson, D. C.; Clark, D. S.; Hinkel, D. E.; Jones, O. S.; Raman, K. S.; Izumi, N.; Fittinghoff, D. N.; Drury, O. B.; Alger, E. T.; Arnold, P. A.; Ashabranner, R. C.; Atherton, L. J.; Barrios, M. A.; Batha, S.; Bell, P. M.; Benedetti, L. R.; Berger, R. L.; Bernstein, L. A.; Berzins, L. V.; Betti, R.; Bhandarkar, S. D.; Bionta, R. M.; Bleuel, D. L.; Boehly, T. R.; Bond, E. J.; Bowers, M. W.; Bradley, D. K.; Brunton, G. K.; Buckles, R. A.; Burkhart, S. C.; Burr, R. F.; Caggiano, J. A.; Callahan, D. A.; Casey, D. T.; Castro, C.; Celliers, P. M.; Cerjan, C. J.; Chandler, G. A.; Choate, C.; Cohen, S. J.; Collins, G. W.; Cooper, G. W.; Cox, J. R.; Cradick, J. R.; Datte, P. S.; Dewald, E. L.; Di Nicola, P.; Di Nicola, J. M.; Divol, L.; Dixit, S. N.; Dylla-Spears, R.; Dzenitis, E. G.; Eckart, M. J.; Eder, D. C.; Edgell, D. H.; Edwards, M. J.; Eggert, J. H.; Ehrlich, R. B.; Erbert, G. V.; Fair, J.; Farley, D. R.; Felker, B.; Fortner, R. J.; Frenje, J. A.; Frieders, G.; Friedrich, S.; Gatu-Johnson, M.; Gibson, C. R.; Giraldez, E.; Glebov, V. Y.; Glenn, S. M.; Glenzer, S. H.; Gururangan, G.; Haan, S. W.; Hahn, K. D.; Hammel, B. A.; Hamza, A. V.; Hartouni, E. P.; Hatarik, R.; Hatchett, S. P.; Haynam, C.; Hermann, M. R.; Herrmann, H. W.; Hicks, D. G.; Holder, J. P.; Holunga, D. M.; Horner, J. B.; Hsing, W. W.; Huang, H.; Jackson, M. C.; Jancaitis, K. S.; Kalantar, D. H.; Kauffman, R. L.; Kauffman, M. I.; Khan, S. F.; Kilkenny, J. D.; Kimbrough, J. R.; Kirkwood, R.; Kline, J. L.; Knauer, J. P.; Knittel, K. M.; Koch, J. A.; Kohut, T. R.; Kozioziemski, B. J.; Krauter, K.; Krauter, G. W.; Kritcher, A. L.; Kroll, J.; Kyrala, G. A.; Fortune, K. N. La; LaCaille, G.; Lagin, L. J.; Land, T. A.; Landen, O. L.; Larson, D. W.; Latray, D. A.; Leeper, R. J.; Lewis, T. L.; LePape, S.; Lindl, J. D.; Lowe-Webb, R. R.; Ma, T.; MacGowan, B. J.; MacKinnon, A. J.; MacPhee, A. G.; Malone, R. M.; Malsbury, T. N.; Mapoles, E.; Marshall, C. D.; Mathisen, D. G.; McKenty, P.; McNaney, J. M.; Meezan, N. B.; Michel, P.; Milovich, J. L.; Moody, J. D.; Moore, A. S.; Moran, M. J.; Moreno, K.; Moses, E. I.; Munro, D. H.; Nathan, B. R.; Nelson, A. J.; Nikroo, A.; Olson, R. E.; Orth, C.; Pak, A. E.; Palma, E. S.; Parham, T. G.; Patel, P. K.; Patterson, R. W.; Petrasso, R. D.; Prasad, R.; Ralph, J. E.; Regan, S. P.; Rinderknecht, H.; Robey, H. F.; Ross, G. F.; Ruiz, C. L.; Seguin, F. H.; Salmonson, J. D.; Sangster, T. C.; Sater, J. D.; Saunders, R. L.; Schneider, M. B.; Schneider, D. H.; Shaw, M. J.; Simanovskaia, N.; Spears, B. K.; Springer, P. T.; Stoeckl, C.; Stoeffl, W.; Suter, L. J.; Thomas, C. A.; Tommasini, R.; Town, R. P.; Traille, A. J.; Wonterghem, B. Van; Wallace, R. J.; Weaver, S.; Weber, S. V.; Wegner, P. J.; Whitman, P. K.; Widmann, K.; Widmayer, C. C.; Wood, R. D.; Young, B. K.; Zacharias, R. A.; Zylstra, A.

    2013-05-01

    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.

  19. Off-site ignition probability of flammable gases.

    Science.gov (United States)

    Rew, P J; Spencer, H; Daycock, J

    2000-01-07

    A key step in the assessment of risk for installations where flammable liquids or gases are stored is the estimation of ignition probability. A review of current modelling and data confirmed that ignition probability values used in risk analyses tend to be based on extrapolation of limited incident data or, in many cases, on the judgement of those conducting the safety assessment. Existing models tend to assume that ignition probability is a function of release rate (or flammable gas cloud size) alone and they do not consider location, density or type of ignition source. An alternative mathematical framework for calculating ignition probability is outlined in which the approach used is to model the distribution of likely ignition sources and to calculate ignition probability by considering whether the flammable gas cloud will reach these sources. Data are collated on the properties of ignition sources within three generic land-use types: industrial, urban and rural. These data are then incorporated into a working model for ignition probability in a form capable of being implemented within risk analysis models. The sensitivity of the model results to assumptions made in deriving the ignition source properties is discussed and the model is compared with other available ignition probability methods.

  20. 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...... for all the test conditions. As the particle is further heated up and the volume-weighted average temperature reaches the onset of rapid decomposition of hemicellulose and cellulose, a secondary homogeneous ignition occurs. The model-predicted ignition delays and burnout times show a good agreement...... with the experimental results. Homogeneous ignition delays are found to scale with specific surface areas while heterogeneous ignition delays show less dependency on the areas. The ignition and burnout are also affected by the process conditions, in which the oxygen concentration is found to have a more pronounced...

  1. FIRST-based survey of Compact Steep Spectrum sources, IV. Multifrequency VLBA observations of very compact objects

    CERN Document Server

    Kunert-Bajraszewska, M; Thomasson, P; Kunert-Bajraszewska, Magdalena; Marecki, Andrzej; Thomasson, Peter

    2006-01-01

    Evidence has been mounting recently that activity in some radio loud AGNs (RLAGNs) can cease shortly after ignition and that perhaps even a majority of very compact sources may be short-lived phenomena because of a lack of stable fuelling from the black hole. Thus, they can fade out before having evolved to large, extended objects. Re-ignition of the activity in such objects is not ruled out. With the aim of finding more examples of these objects and to investigate if they could be RLAGNs switched off at very early stages of their evolution, multifrequency VLBA observations of six sources with angular sizes significantly less than an arcsecond, yet having steep spectra, have been made. Observations were initially made at 1.65 GHz using the VLBA with the inclusion of Effelsberg telescope. The sources were then re-observed with the VLBA at 5, 8.4 and 15.4 GHz. All the observations were carried out in a snapshot mode with phase referencing. One of the sources studied, 0809+404, is dominated by a compact componen...

  2. 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.

  3. Influence of CT-based attenuation correction on dopamine transporter SPECT with [(123)I]FP-CIT.

    Science.gov (United States)

    Lapa, Constantin; Spehl, Timo S; Brumberg, Joachim; Isaias, Ioannis U; Schlögl, Susanne; Lassmann, Michael; Herrmann, Ken; Meyer, Philipp T

    2015-01-01

    Dopamine transporter (DAT) imaging using single-photon emission computed tomography (SPECT) and (123)I-labelled radiopharmaceuticals like [(123)I]FP-CIT is an established part in the diagnostic work-up of parkinsonism. Guidelines recommend attenuation correction (AC), either by a calculated uniform attenuation matrix (calAC) or by a measured attenuation map (nowadays done by low-dose CT; CTAC). We explored the impact of CTAC compared to conventional calAC on diagnostic accuracy and the use of DAT availability as a biomarker of nigrostriatal integrity.Integrated SPECT/CT studies with [(123)I]FP-CIT were performed in patients with Parkinson's disease (PD; n = 15) and essential tremor (ET; n = 15). SPECT data was reconstructed with calAC, CTAC and without AC (noAC). Regional DAT availability was assessed by uniform volume-of-interest analyses providing striatal binding potential (BP ND) estimates. BP ND values were compared among methods and correlated with clinical parameters. Compared to calAC, both CTAC and noAC provided significantly lower, but highly linearly correlated BP ND estimates (R (2) = 0.96). Diagnostic performance to distinguish between patients with PD and those with ET was very high and did not differ between AC methods. CTAC and noAC data tended so show a stronger correlation with severity and duration of disease in PD and age in ET than did calAC. Defining the reference region on low-dose CT instead of SPECT did not consistently alter findings. [(123)I]FP-CIT SPECT provides a very high diagnostic accuracy for differentiation between PD and ET that is not dependent on the employed AC method. Preliminary correlations analyses suggest that BP ND estimates derived from CTAC represent a superior biomarker of nigrostriatal integrity.

  4. Combustion characteristics of spark-ignition and pilot flame ignition systems in a model Wankel stratified charge engine

    Energy Technology Data Exchange (ETDEWEB)

    Muroki, T. [Kanagawa Inst. of Technology, Dept. of Mechanical Engineering, Kanagawa (Japan); Moriyoshi, Y. [Chiba Univ., Dept. of Electronics and Mechanical Engineering, Chiba (Japan)

    2000-11-01

    In a stratified charge engine, a glow plug pilot flame ignition system has been compared with a spark-ignition system for a model stratified charge Wankel combustion chamber. A motored two-stroke diesel engine was operated as a rapid compression and expansion machine with the cylinder head replaced by a model Wankel combustion chamber designed to simulate the temporal changes of air flow and pressure fields inside the chamber of an actual engine. It was found that the pilot flame ignition system had better ignitability and improved combustion characteristics, especially in the lean mixture range, relative to the spark-ignition system. (Author)

  5. Progress in Compact Toroid Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, Thomas James

    2002-09-01

    The term "compact toroids" as used here means spherical tokamaks, spheromaks, and field reversed configurations, but not reversed field pinches. There are about 17 compact toroid experiments under construction or operating, with approximate parameters listed in Table 1.

  6. Influence of CT-based attenuation correction on dopamine transporter SPECT with [123I]FP-CIT

    OpenAIRE

    Lapa, Constantin; Spehl, Timo S; Brumberg, Joachim; Isaias, Ioannis U; Schlögl, Susanne; Lassmann, Michael; Herrmann, Ken; Philipp T. Meyer

    2015-01-01

    Dopamine transporter (DAT) imaging using single-photon emission computed tomography (SPECT) and 123I-labelled radiopharmaceuticals like [123I]FP-CIT is an established part in the diagnostic work-up of parkinsonism. Guidelines recommend attenuation correction (AC), either by a calculated uniform attenuation matrix (calAC) or by a measured attenuation map (nowadays done by low-dose CT; CTAC). We explored the impact of CTAC compared to conventional calAC on diagnostic accuracy and the use of DAT...

  7. The National Ignition Facility (NIF) and the National Ignition Campaign (NIC)

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E

    2009-09-17

    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). NIF construction was certified by the Department of Energy as complete on March 27, 2009. NIF, a 192-beam Nd:glass laser facility, will ultimately produce 1.8-MJ, 500-TW of 351-nm third-harmonic, ultraviolet light. On March 10, 2009, 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 broader frontier scientific exploration. NIF experiments in support of indirect-drive ignition began in August 2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a 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 includes diagnostics, a 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, integrated into the facility, and 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 of Inertial Fusion Energy (IFE) and will

  8. 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.

  9. Compact fiber optic accelerometer

    Institute of Scientific and Technical Information of China (English)

    Feng Peng; Jun Yang; Bing Wu; Yonggui Yuan; Xingliang Li; Ai Zhou; Libo Yuan

    2012-01-01

    A compact fiber optic accelerometer based on a Michelson interferometer is proposed and demonstrated.In the proposed system,the sensing element consists of two single-mode fibers glued together by epoxy,which then act as a simple supported beam.By demodulating the optical phase shift,the acceleration is determined as proportional to the force applied on the central position of the two single-mode fibers.This simple model is able to calculate the sensitivity and the resonant frequency of the compact accelerometer.The experimental results show that the sensitivity and the resonant frequency of the accelerometer are 0.42 rad/g and 600 Hz,respectively.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Rapid ignition of fluidized bed boiler

    Science.gov (United States)

    Osborn, Liman D.

    1976-12-14

    A fluidized bed boiler is started up by directing into the static bed of inert and carbonaceous granules a downwardly angled burner so that the hot gases cause spouting. Air is introduced into the bed at a rate insufficient to fluidize the entire bed. Three regions are now formed in the bed, a region of lowest gas resistance, a fluidized region and a static region with a mobile region at the interface of the fluidized and static regions. Particles are transferred by the spouting action to form a conical heap with the carbonaceous granules concentrated at the top. The hot burner gases ignite the carbonaceous matter on the top of the bed which becomes distributed in the bed by the spouting action and bed movement. Thereafter the rate of air introduction is increased to fluidize the entire bed, the spouter/burner is shut off, and the entire fluidized bed is ignited.

  15. Ignition transient analysis of solid rocket motor

    Science.gov (United States)

    Han, Samuel S.

    1991-01-01

    Measurement data on the performance of Space Shuttle Solid Rocket Motor show wide variations in the head-end pressure changes and the total thrust build-up during the ignition transient periods. To analyze the flow and thermal behavior in the tested solid rocket motors, a 1-dimensional, ideal gas flow model via the SIMPLE algorithm was developed. Numerical results showed that burning patterns in the star-shaped head-end segment of the propellant and the erosive burning rate are two important factors controlling the ignition transients. The objective of this study is to extend the model to include the effects of aluminum particle commonly used in solid propellants. To treat the effects of aluminum-oxide particles in the combustion gas, conservation of mass, momentum, and energy equations for the particles are added in the numerical formulation and integrated by an inter-phase-slip algorithm.

  16. 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...

  17. Identificació i caracterització dels executors de la mort cel·lular per isquèmia en els cardiomiòcits

    OpenAIRE

    Bahi i Pla, Núria

    2008-01-01

    L'objectiu principal d'aquest treball ha estat la caracterització del procés demort cel·lular en la isquèmia en els cardiomiòcits. En el nostre estudi hem demostratque l'expressió de les principals proteïnes reguladores de la mort cel·lular dependentde caspases es reprimeix durant el desenvolupament cardíac. En correlació ambaquest fet hem observat que la mort cel·lular induïda per isquèmia és dependent decaspases als cardiomiòcits embrionals, mentre que els cardiomiòcits postmitòticsmoren de...

  18. Control of Ignition and Combustion of Dimethyl Ether in Homogeneous Charge Compression Ignition Engine

    Science.gov (United States)

    Kim, Kyoung-Oh; Azetsu, Akihiko; Oikawa, Chikashi

    A homogeneous charge compression ignition (HCCI) engine is known to have high thermal efficiency and low nitrogen oxide emission. However, the control of ignition timing and its combustion period over a wide range of engine speeds and loads is one of the barriers to the realization of the engine. On the lean side of the equivalence ratio, control of ignition is difficult due to its long delay of ignition, and there is knocklike problem under high load. In both computations and experiments of HCCI engine operated on dimethyl ether, the operable range (the possible range of fuel input from just ignitable to knock-occurring state) shifted to the rich side with decreasing intake temperature and amount of mixing of carbon dioxide. The range of fuel input was reduced at low intake temperatures, because the hot flame onset angle advanced more quickly than it did at high intake temperatures. However, the mixing of CO2 caused the operable range to shift to the rich side while retaining the same range. The results of this study indicated the possibility of high-load operation or extension of the load range by exhaust gas recirculation.

  19. The National Ignition Campaign: status and progress

    Science.gov (United States)

    Moses, E. I.; Collaborators, the NIC

    2013-10-01

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been operational since March 2009 and a variety of experiments have been completed and many more are planned in support of NIF's mission areas: national security, fundamental science, and fusion energy. NIF capabilities and infrastructure are in place to support all of its missions with nearly 60 x-ray, optical and nuclear diagnostic systems and the ability to shoot cryogenic targets and DT layered capsules. The NIF has also been qualified for the use of tritium and other special materials as well as to perform high-yield experiments and classified experiments. Implosions with record indirect-drive neutron yield of 7.5 × 1014 neutrons have been achieved. NIF, a Nd : Glass laser facility, is routinely operating at 1.6 MJ of ultraviolet (3ω) light on target with very high reliability. It recently reached its design goal of 1.8 MJ and 500 TW of 3ω light on target, and has performed target experiments with 1.9 MJ at peak powers of 410 TW. The National Ignition Campaign (NIC), an international effort with the goal of demonstrating thermonuclear burn in the laboratory, is making steady progress towards achieving ignition. Other experiments have been completed in support of high-energy science, materials equation of state, and materials strength. In all cases, records of extreme temperatures and pressures, highest neutron yield and highest energy densities have been achieved. This paper describes the unprecedented experimental capabilities of the NIF and the results achieved so far on the path towards ignition.

  20. The Velocity Campaign for Ignition on NIF

    Science.gov (United States)

    Callahan, Debra

    2011-10-01

    Achieving ignition requires a high velocity implosion since the energy required for ignition scales like 1/v8. Beyond ignition, a higher velocity produces more robust performance, which will be useful for applications of ignition. In the velocity campaign, we will explore three methods for increasing implosion velocity: increased laser power and energy, optimized hohlraum and capsule materials, and optimized capsule thickness. The main issue with increasing the laser power and energy is the way in which LPI (laser plasma interactions) and hot electron preheat will change as we increase the laser power. Based on scalings from previous data and theory, we expect to couple 80-85% of 1.5 MJ at 475-500 TW. We can also increase the velocity by optimizing the hohlraum and capsule materials. In this campaign, we will explore depleted uranium hohlraums to reduce wall loss and optimize the capsule dopant by replacing the germanium dopant with silicon. Those two changes are expected to increase velocity by 6-7%. Finally, we will optimize the capsule thickness. The optimal capsule thickness is a trade-off between velocity and mix. A thinner capsule has higher velocity, but is more susceptible to mix of the ablator material into the hotspot due to hydrodynamic instabilities seeded by ablation surface imperfections. Once we have achieved adequate capsule areal density, we will optimize the velocity/mix trade off by varying the capsule thickness. We will also make direct measure of Rayleigh-Taylor instability growth by backlighting the growth of engineered features on the surface of the capsule. This will allow us to benchmark our models of mix. In this paper, we will describe the designs and experimental results of the velocity campaign. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  1. 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.

  2. 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.

  3. 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)

  4. 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.

  5. Fielding the NIF Cryogenic Ignition Target

    Energy Technology Data Exchange (ETDEWEB)

    Malsbury, T; Haid, B; Gibson, C; Atkinson, D; Skulina, K; Klingmann, J; Atherton, J; Mapoles, E; Kozioziemski, B; Dzenitis, E

    2008-02-28

    The United States Department of Energy has embarked on a campaign to conduct credible fusion ignition experiments on the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in 2010. The target assembly specified for this campaign requires the formation of a deuterium/tritium (DT) fuel ice layer on the inside of a 2 millimeter diameter capsule positioned at the center of a 9 millimeter long by 5 millimeter diameter cylinder, called a hohlraum. The ice layer requires micrometer level accuracy and must be formed and maintained at temperatures below 19 K. At NIF shot time, the target must be positioned at the center of the NIF 10 meter diameter target chamber, aligned to the laser beam lines and held stable to less than 7 micrometers rms. We have completed the final design and are integrating the systems necessary to create, characterize and field the cryogenic target for ignition experiments. These designs, with emphasis on the challenges of fielding a precision cryogenic positioning system will be presented.

  6. 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.

  7. 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;.

  8. Hydraulic conductivity of compacted zeolites.

    Science.gov (United States)

    Oren, A Hakan; Ozdamar, Tuğçe

    2013-06-01

    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  9. 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

  10. [{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.)

  11. Topography of cerebral monoamine transporter availability in families with SCA2 mutations: a voxel-wise [{sup 123}I]{beta}-CIT SPECT analysis

    Energy Technology Data Exchange (ETDEWEB)

    Scherfler, Christoph; Boesch, Sylvia M.; Seppi, Klaus; Wenning, Gregor K.; Poewe, Werner [Innsbruck Medical University, Department of Neurology, Innsbruck (Austria); Donnemiller, Eveline; Virgolini, Irene [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria); Weirich-Schwaiger, Helga [Innsbruck Medical University, Department of Biology and Human Genetics, Innsbruck (Austria); Goebel, Georg [Innsbruck Medical University, Department of Medical Statistics, Informatics and Health Economics, Innsbruck (Austria)

    2006-09-15

    The purpose of this study was to investigate the monoamine transporter status of dopamine, serotonin and norepinephrine throughout the brain in spinocerebellar ataxia type 2 (SCA2). To this end, nine patients were studied with [{sup 123}I]{beta}-CIT SPECT. Data were compared with ten age-matched healthy control subjects and ten patients with young-onset Parkinson's disease (YOPD), matched for age. Parametric SPECT images of the specific-to-non-displaceable equilibrium partition coefficient (V{sub 3}{sup ''}), which is proportional to the receptor density (B{sub max}), were generated. In order to objectively localise focal changes in {beta}-CIT uptake throughout the brain volume without having to make an a priori hypothesis as to their location, statistical parametric mapping (SPM) was applied to SPECT images. Data clusters revealed by SPM, showing significant differences in V{sub 3}{sup ''} values between groups, were transformed onto the individual V{sub 3}{sup ''} image to obtain mean regional uptake values. Both SCA2 and YOPD patients showed significant decreases in striatal [{sup 123}I]{beta}-CIT SPECT uptake when compared with controls. However, in SCA2 patients, additional reductions in caudate/anterior putamen, midbrain and pons [{sup 123}I]{beta}-CIT uptake were localised with SPM. Voxel-wise analysis of [{sup 123}I]{beta}-CIT SPECT revealed more widespread decline of monoamine transporter availability in SCA2 than in YOPD, reflecting differences in the underlying pathology. We suggest that the quantification of midbrain and pons [{sup 123}I]{beta}-CIT signal is likely to improve the diagnostic accuracy in patients presenting with clinical features of both SCA2 and YOPD at initial investigation. (orig.)

  12. Une frontière en mouvement : espace public, espace privé dans les cités mayas (Basses Terres centrales et méridionales)

    OpenAIRE

    Bazy, Damien

    2014-01-01

    Une frontière en mouvement : espace public, espace privé dans les cités mayas (Basses Terres centrales et méridionales). Cet article traite de l’organisation interne des centres monumentaux des cités mayas classiques à travers une approche innovante. Elle consiste à distinguer les modalités d’interaction spatiale caractérisées par le contact de deux catégories d’espaces, les uns publics et les autres privés, selon une opposition plus efficace que la traditionnelle dichotomie du politico-relig...

  13. Localized flame extinction and re-ignition in turbulent jet ignition assisted combustion

    Science.gov (United States)

    Validi, Abdoulahad; Schock, Harold; Jaberi, Farhad; Computational Fluid Dynamics Laboratory Team

    2016-11-01

    Direct numerical simulations (DNS) of turbulent jet ignition (TJI)-assisted combustion of ultra-lean fuel-air is performed in a three-dimensional planar jet configuration. TJI is a novel ignition enhancement method which facilitates the combustion of lean and ultra-lean mixtures by rapidly exposing them to high temperature combustion products. Fully compressible gas dynamics and species equations are solved with high order finite difference methods. The hydrogen-air reaction is simulated with a detailed chemical kinetics mechanism consisting of 9 species and 38 elementary reactions. The interesting phenomena involved in TJI combustion including localized premixed flame extinction/re-ignition and simultaneous premixed/non-premixed flames are investigated by using the flame heat release, temperature, species concentrations, and a newly defined TJI progress variable.

  14. Some Observations on the Ignition of Composite Solid Propellants

    Directory of Open Access Journals (Sweden)

    K. Kishore

    1995-07-01

    Full Text Available Heat-up times derived from studies on the ignition characteristics of a few model composite solid propellants, containing polystyrene, carboxy-terminated polybutadiene, plasticised polyvinyl chloride and polyphenol formaldehyde as binders, show that they are directly proportional to the mass of the sample and inversely proportional to the heat flux. Propellant weight-loss prior to ignition and high pressure ignition temperature data on the propellants, ammonium per chlorate, and binders show that the ignition is governed by the gasification of the binder pyrolysis products. The activation energy for the gasification of the pyrolysed polymer products corresponds to their ignition behaviour suggesting that propellant ignition is controlled by the binder.

  15. 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.

  16. 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.

  17. Compact synchrotron light sources

    CERN Document Server

    Weihreter, Ernst

    1996-01-01

    This book covers a new niche in circular accelerator design, motivated by the promising industrial prospects of recent micromanufacturing methods - X-ray lithography, synchrotron radiation-based micromachining and microanalysis techniques. It describes the basic concepts and the essential challenges for the development of compact synchrotron radiation sources from an accelerator designer's point of view and gives an outline of the actual state of the art. The volume is intended as an introduction and as a reference for physicists, engineers and managers involved in this rapidly developing fiel

  18. Compact LINAC for deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S S [Los Alamos National Laboratory; O' Hara, J F [Los Alamos National Laboratory; Rybarcyk, L J [Los Alamos National Laboratory

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  19. Laser diode ignition activities at Sandia National Laboratories

    Science.gov (United States)

    Merson, John A.; Salas, F. Jim; Chow, Weng W.; Clements, J. W.; Kass, William J.

    1993-01-01

    The topics are presented in viewgraph form and include the following: ignition subsystems, enhanced safety, optical ordnance power densities, optical ignition factors, low energy optical ordnance program, absorptance of 2-(5-cyanotetrazolato) pentaaminecobalt(III) perchlorate (CP) near 800 nm, power dependence of doped CP, system operational electrical requirements, dopant concentration effects for different CP particle sizes, ZR/KCLO4 optical ignition thresholds, and electrostatic discharge testing.

  20. Synthesis and the crystal and molecular structure of the silver(I)-germanium(IV) polymeric complex with citrate anions {[Ag2Ge(H Cit)2(H2O)2] • 2H2O} n

    Science.gov (United States)

    Sergienko, V. S.; Martsinko, E. E.; Seifullina, I. I.; Churakov, A. V.; Chebanenko, E. A.

    2016-03-01

    The synthesis and X-ray diffraction study of compound {[Ag2Ge(H Cit)2(H2O)2] • 2H2O} n , where H4 Cit is the citric acid, are performed. In the polymeric structure, the H Cit 3- ligand fulfils the tetradentate chelate-μ4-bridging (3Ag, Ge) function (tridentate with respect to Ge and Ag atoms). The Ge atom is octahedrally coordinated by six O atoms of two H Cit 3-ligands. The coordination polyhedron of the Ag atom is an irregular five-vertex polyhedron [four O atoms of four H Cit 3- ligands and the O(H2O) atom]. An extended system of O-H···O hydrogen bonds connects complex molecules into a supramolecular 3D-framework.

  1. 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...

  2. 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.

  3. 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...

  4. Hydrodynamic modeling and simulations of shock ignition thresholds

    Directory of Open Access Journals (Sweden)

    Lafon M.

    2013-11-01

    Full Text Available The Shock Ignition (SI scheme [1] offers to reduce the laser requirements by relaxing the implosion phase to sub-ignition velocities and later adding an intense laser spike. Depending on laser energy, target characteristics and implosion velocity, high gains are expected [2,3]. Relevant intensities for scaled targets imploded in the velocity range from 150 to 400 km/s are defined at ignition thresholds. A range of moderate implosion velocities is specified to match safe implosions. These conditions for target design are then inferred for relevant NIF and LMJ shock-ignited targets.

  5. 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.

  6. Review on performance of High energy ignition techniques

    Directory of Open Access Journals (Sweden)

    Jubin V Jose

    2015-12-01

    Full Text Available Ignition systems are the fundamental parts of spark ignition engines which determine the engine efficiency and pollutant emission. With the recent developments in engine technology significantly high spark energies are required. This paper reviews progress in alternative ignition systems that supply high energy sparks and more efficiently transfer energy to the gas mixture. The improvement in performance parameter of a spark plug such as net heat transfer rate, flame development time, exhaust gas emission rate are compared with conventional ignition systems. This paper also tries to identify critical research gap and also the advantages and limitations of advanced systems with reference to the advanced researches reported in this area.

  7. A compact SADM family

    Science.gov (United States)

    Barbet, Vincent; Le Quintrec, Cyrille; Jeandot, Xavier; Chaix, Alain; Grain, Eric; Roux, Jerome

    2005-07-01

    Alcatel Space has developed a new SADM family driven by cost, modularity, mass and performances. The modularity concept is based on separating the rotation drive function from the electrical transfer function. The drive actuator has been designed for various applications where pointing and reliability is needed. It can be associated with high dissipative rotary devices (SA collectors, RF joints..). The design goal was to minimize the number of parts in order to reach the most simple and compact mechanism. Mass reduction was achieved by reducing as much as possible the load path between the Solar Array interface and the spacecraft interface. Following these guidelines, the drive actuator was developed and qualified on ATV SADM (part od Alcatel Space Solar Array Drive Sub System for ATV). Further more a high power integrated collector was qualified inside the SADM for Geo-stationary telecom satellite (SPACEBUS platforms). Fine thermal and mechanical modeling was necessary to predict SADM behaviors for the numerous thermal environments over the missions (steady and transient cases). These modeling were well correlated through mechanical and thermal balances qualification tests. The challenging approach of thermal dissipation in a compact design leads to a family of 3 SADM capabilities form 2kW up to 15kW per SADM weighing less than 4.5 kg each.

  8. Compaction of Titanium Powders

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, Stephen,J; Jablonski, Paul, J

    2011-05-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines<150 {micro}m,<75 {micro}m, and<45 {micro}m; two different sizes of a hydride-dehydride [HDH]<75 {micro}m and<45 {micro}m; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

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

    Directory of Open Access Journals (Sweden)

    Ihab Sraj

    2013-01-01

    Full Text Available 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.

  10. 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

  11. On stable compact minimal submanifolds

    CERN Document Server

    Torralbo, Francisco

    2010-01-01

    Stable compact minimal submanifolds of the product of a sphere and any Riemannian manifold are classified whenever the dimension of the sphere is at least three. The complete classification of the stable compact minimal submanifolds of the product of two spheres is obtained. Also, it is proved that the only stable compact minimal surfaces of the product of a 2-sphere and any Riemann surface are the complex ones.

  12. 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.

  13. Sensitivity of Liquid Monopropellants to Compression Ignition

    Science.gov (United States)

    1982-06-01

    contains a Silicon Rubber Septum through which a Gas Ullage Syringe,i.e., hypodermic needle , passes to introduce a precise loading of air ullage (volume...dumbbell by use of a hypodermic needle during the pre-fill procedure. Both head and rear of the dumbbell are fitted with "O"-ring seals. Thus, should...ignition tests support this theory . Again, returning to Figure 29, the response of a rapid-load pre-pressurized NOS-365 liquid monopropellant nharge (p

  14. Ignition and combustion features of biofuels

    Science.gov (United States)

    Ryzhkov, A. F.; Silin, V. E.; Bogatova, T. F.; Nadir, S. M.

    2011-07-01

    This paper presents the results of experimental investigations of the ignition and combustion of plant biofuels (wood particles, date stones) and products of their mechanical and thermal treatment (pellets, charcoal) at temperatures typical of the burning process in nonforced furnaces and fixed-bed and fluidized-bed gas producers. The influence of the furnace heat treatment of a fuel on its inflammation and combustion has been revealed. The results have been compared with the known data on the burning of pellets, brown coals, and anthracites and with the calculation by the classical diffusion-kinetic model.

  15. 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.

  16. Implementation of the European multicentre database of healthy controls for [(123)I]FP-CIT SPECT increases diagnostic accuracy in patients with clinically uncertain parkinsonian syndromes

    DEFF Research Database (Denmark)

    Albert, Nathalie L; Unterrainer, Marcus; Diemling, Markus;

    2016-01-01

    PURPOSE: Even though [(123)I]FP-CIT SPECT provides high accuracy in detecting nigrostriatal cell loss in neurodegenerative parkinsonian syndromes (PS), some patients with an inconclusive diagnosis remain. We investigated whether the diagnostic accuracy in patients with clinically uncertain PS wit...

  17. 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

    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...

  18. No difference in striatal dopamine transporter availability between active smokers, ex-smokers and non-smokers using (123I)FP-CIT (DaTSCAN) and SPECT

    DEFF Research Database (Denmark)

    Thomsen, G; Knudsen, Gitte Moos; Jensen, PS;

    2013-01-01

    tobacco smoking: (1) non-smokers (n = 64), (2) ex-smokers (n = 39) and (3) active smokers (n = 26). For imaging of the DAT availability, we used [123I]FP-CIT (DaTSCAN) and single photon emission computed tomography (SPECT). Data were collected in collaboration between 13 SPECT centres located in 10...

  19. 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.)

  20. Repeated administration of D-amphetamine induces loss of [{sup 123}I]FP-CIT binding to striatal dopamine transporters in rat brain: a validation study

    Energy Technology Data Exchange (ETDEWEB)

    Booij, Jan [Department of Nuclear Medicine, Academic Medical Center, 1105 AZ Amsterdam (Netherlands)]. E-mail: j.booij@amc.uva.nl; Bruin, Kora de [Department of Nuclear Medicine, Academic Medical Center, 1105 AZ Amsterdam (Netherlands); Gunning, W. Boudewijn [Department of Neurology, Epilepsy Centre Kempenhaeghe, 5590 AB Heeze (Netherlands)

    2006-04-15

    In recent years, several PET and SPECT studies have shown loss of striatal dopamine transporter (DAT) binding in amphetamine (AMPH) users. However, the use of DAT SPECT tracers to detect AMPH-induced changes in DAT binding has not been validated. We therefore examined if repeated administration of D-AMPH or methamphetamine (METH) may induce loss of binding to striatal DATs in rats by using an experimental biodistribution study design and a SPECT tracer for the DAT ([{sup 123}I]FP-CIT). Methods: Groups of male rats (n=10 per group) were treated with D-AMPH (10 mg/kg body weight), METH (10 mg/kg body weight), or saline, twice a day for 5 consecutive days. Five days later, [{sup 123}I]FP-CIT was injected intravenously, and 2 h later, the rats were sacrificed and radioactivity was assayed. Results: In D-AMPH but not METH-treated rats, striatal [{sup 123}I]FP-CIT uptake was significantly lower (approximately 17%) than in the control group. Conclusion: These data show that [{sup 123}I]FP-CIT can be used to detect AMPH-induced changes in DAT binding and may validate the use of DAT radiotracers to study AMPH-induced changes in striatal DAT binding in vivo.

  1. 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;

    2014-01-01

    cognitive information processing deficits such as slowed processing speed. Parkinson's disease is characterised by the degeneration of the midbrain dopaminergic system and is associated with cognitive dysfunction, including slowed information processing. Although sensorimotor processes in Parkinson......'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...... performed better on cognitive measures tapping attention and processing speed than patients with a lower level of prepulse inhibition group. Furthermore, there were significant correlations between prepulse inhibition and 123I-FP-CIT uptake in the striatum. Conclusions: Our results suggest that the level...

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

    OpenAIRE

    José García-Romeu

    2009-01-01

    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 a...

  3. 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.

  4. William Grossin, J’ai connu le Moyen-Âge. Récit de vie : enfance

    Directory of Open Access Journals (Sweden)

    Charles Gadea

    2009-06-01

    Full Text Available À côté de son œuvre scientifique, William Grossin a publié une série de livres relevant de divers genres : plusieurs romans, des poèmes satiriques et un récit de vie évoquant son enfance. Avec un peu d’attention, on pourra reconnaître dans chacun d’eux la « touche » d’un auteur tardif mais productif. Il y a d’abord  son style : travaillé, nerveux, vivant, sobre et même un peu austère mais sans excès, comme certains Vouvray secs. Les mots sont choisis avec soin, à tel point que les phrases com...

  5. La couleur oubliée des cités historiques portugaises et le cas du palais de Queluz

    OpenAIRE

    Aguiar, José

    2008-01-01

    On voit ce que l’on apprend à voir. Trop longtemps, on a cru que la couleur des cités historiques portugaises était répartie entre un Nord de culture atlantique (où l’authenticité des matériaux naturels prédomine) et un Sud méditerranéen favorisant la sensualité blanche (mortier et chaux) ; les azulejos sont, eux, comme une rêverie du xixe siècle. Longtemps, on a résolu la difficulté de la présentation architecturale des monuments anciens au public en s’appuyant sur ce modèle simpliste. Aujou...

  6. Ignition analysis of a porous energetic material. 2. Ignition at a closed heated end

    Energy Technology Data Exchange (ETDEWEB)

    Alexander M. Telegentor; Stephen B. Margolis; Forman A. Williams

    1998-11-01

    A continuation of an ignition analysis for porous energetic materials subjected to a constant energy flux is presented. In the first part, the analysis was developed for the case of an open-end, semi-infinite material such that gas flow, generated by thermal expansion, flowed out of the porous solid, thereby removing energy from the system. In the present study, the case of a closed end is considered, and thus the thermally-induced gas flow is now directed into the solid. In these studies, an asymptotic perturbation analysis, based on the smallness of the gas-to-solid density ratio and the largeness of the activation energy, is utilized to describe the inert and transition stages leading to thermal runaway. In both cases it is found that the effects of porosity provide a leading-order reduction in the time to ignition relative to that for the nonporous problem, arising from the reduced amount of solid material that must be heated and the difference in thermal conductivities of the solid and gaseous phases. A correction to the leading-order ignition-delay time, however, is provided by the convective flow of gas through the solid, and the sign of this correction is shown to depend on the direction of the gas flow. Thus, gas flowing out of an open-end solid was previously shown to give a positive correction to the leading-order time to ignition. Here, however, it is demonstrated that when the flow of gas is directed into the porous solid, the relative transport effects associated with the gas flow serve to preheat the material, resulting in a negative correction and hence a decrease in the ignition-delay time.

  7. 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.

  8. Combined visual and semi-quantitative assessment of (123)I-FP-CIT SPECT for the diagnosis of dopaminergic neurodegenerative diseases.

    Science.gov (United States)

    Ueda, Jun; Yoshimura, Hajime; Shimizu, Keiji; Hino, Megumu; Kohara, Nobuo

    2017-04-07

    Visual and semi-quantitative assessments of (123)I-FP-CIT single-photon emission computed tomography (SPECT) are useful for the diagnosis of dopaminergic neurodegenerative diseases (dNDD), including Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy, multiple system atrophy, and corticobasal degeneration. However, the diagnostic value of combined visual and semi-quantitative assessment in dNDD remains unclear. Among 239 consecutive patients with a newly diagnosed possible parkinsonian syndrome who underwent (123)I-FP-CIT SPECT in our medical center, 114 patients with a disease duration less than 7 years were diagnosed as dNDD with the established criteria or as non-dNDD according to clinical judgment. We retrospectively examined their clinical characteristics and visual and semi-quantitative assessments of (123)I-FP-CIT SPECT. The striatal binding ratio (SBR) was used as a semi-quantitative measure of (123)I-FP-CIT SPECT. We calculated the sensitivity and specificity of visual assessment alone, semi-quantitative assessment alone, and combined visual and semi-quantitative assessment for the diagnosis of dNDD. SBR was correlated with visual assessment. Some dNDD patients with a normal visual assessment had an abnormal SBR, and vice versa. There was no statistically significant difference between sensitivity of the diagnosis with visual assessment alone and semi-quantitative assessment alone (91.2 vs. 86.8%, respectively, p = 0.29). Combined visual and semi-quantitative assessment demonstrated superior sensitivity (96.7%) to visual assessment (p = 0.03) or semi-quantitative assessment (p = 0.003) alone with equal specificity. Visual and semi-quantitative assessments of (123)I-FP-CIT SPECT are helpful for the diagnosis of dNDD, and combined visual and semi-quantitative assessment shows superior sensitivity with equal specificity.

  9. 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...

  10. 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....

  11. 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.

  12. 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...

  13. 33 CFR 183.440 - Secondary circuits of ignition systems.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Secondary circuits of ignition systems. 183.440 Section 183.440 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Requirements § 183.440 Secondary circuits of ignition systems. (a) Each conductor in a secondary circuit of...

  14. Hot-wire ignition of AN-based emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, Richard; Goldthorp, Sandra; Badeen, Christopher M. [Canadian Explosives Research Laboratory, Natural Resources Canada, Ottawa, Ontario, K1A 0G1 (Canada); Chan, Sek Kwan [Orica Canada Inc., Brownsburg-Chatham, Quebec (Canada)

    2008-12-15

    Emulsions based on ammonium nitrate (AN) and water locally ignited by a heat source do not undergo sustained combustion when the pressure is lower than some threshold value usually called the Minimum Burning Pressure (MBP). This concept is now being used by some manufacturers as a basis of safety. However, before a technique to reliably measure MBP values can be designed, one must have a better understanding of the ignition mechanism. Clearly, this is required to avoid under ignitions which could lead to the erroneous interpretation of failures to ignite as failures to propagate. In the present work, facilities to prepare and characterize emulsions were implemented at the Canadian Explosives Research Laboratory. A calibrated hot-wire ignition system operated in a high-pressure vessel was also built. The system was used to study the ignition characteristics of five emulsion formulations as a function of pressure and ignition source current. It was found that these mixtures exhibit complicated pre-ignition stages and that the appearance of endotherms when the pressure is lowered below some threshold value correlates with the MBP. Thermal conductivity measurements using this hot-wire system are also reported. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  15. High-pressure ignition plasma torch for aerospace testing facilities

    Science.gov (United States)

    Yusupov, D. I.; Kulikov, Yu M.; Gadzhiev, M. Kh; Tyuftyaev, A. S.; Son, E. E.

    2016-11-01

    The present paper discusses the issues of implementation of high-pressure ignition plasma torch in terms of discharge phenomena in compressed gases, dense nitrogen plasma properties and stable arcing power requirements. Contact ignition has been tested in a pressure range p = 1-25 bar and has proved to be a reliable solution for pilot arc burning.

  16. The lean burn direct injection jet ignition gas engine

    Energy Technology Data Exchange (ETDEWEB)

    Boretti, Alberto A.; Watson, Harry C. [School of Science and Engineering, University of Ballarat, PO Box 663, Ballarat, Victoria 3353 (Australia)

    2009-09-15

    This paper presents a new in-cylinder mixture preparation and ignition system for various fuels including hydrogen, methane and propane. The system comprises a centrally located direct injection (DI) injector and a jet ignition (JI) device for combustion of the main chamber (MC) mixture. The fuel is injected in the MC with a new generation, fast actuating, high pressure, high flow rate DI injector capable of injection shaping and multiple events. This injector produces a bulk, lean stratified mixture. The JI system uses a second DI injector to inject a small amount of fuel in a small pre-chamber (PC). In the spark ignition (SI) version, a spark plug then ignites a slightly rich mixture. In the auto ignition version, a DI injector injects a small amount of higher pressure fuel in the small PC having a hot glow plug (GP) surface, and the fuel auto ignites in the hot air or when in contact with the hot surface. Either way the MC mixture is then bulk ignited through multiple jets of hot reacting gases. Bulk ignition of the lean, jet controlled, stratified MC mixture resulting from coupling DI with JI makes it possible to burn MC mixtures with fuel to air equivalence ratios reducing almost to zero for a throttle-less control of load diesel-like and high efficiencies over almost the full range of loads. (author)

  17. Estimating soil organic carbon through loss on ignition

    NARCIS (Netherlands)

    Hoogsteen, M.J.J.; Lantinga, E.A.; Bakker, E.J.; Groot, J.C.J.; Tittonell, P.A.

    2015-01-01

    Loss on ignition (LOI) is one of the most widely used methods for measuring organic matter content in soils but does not have a universal standard protocol. A large number of factors may influence its accuracy, such as furnace type, sample mass, duration and temperature of ignition and clay conte

  18. National Ignition Facility project acquisition plan

    Energy Technology Data Exchange (ETDEWEB)

    Callaghan, R.W.

    1996-04-01

    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.

  19. PBXN-9 Ignition Kinetics and Deflagration Rates

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, E; Maienschein, J; Burnham, A; Koerner, J; Hsu, P; Wemhoff, A

    2008-04-24

    The ignition kinetics and deflagration rates of PBXN-9 were measured using specially designed instruments at LLNL and compared with previous work on similar HMX based materials. Ignition kinetics were measured based on the One Dimensional Time-to-Explosion combined with ALE3D modeling. Results of these experiments indicate that PBXN-9 behaves much like other HMX based materials (i.e. LX-04, LX-07, LX-10 and PBX-9501) and the dominant factor in these experiments is the type of explosive, not the type of binder/plasticizer. In contrast, the deflagration behavior of PBXN-9 is quite different from similar high weight percent HMX based materials (i.e LX-10, LX-07 and PBX-9501). PBXN-9 burns in a laminar manner over the full pressure range studied (0-310 MPa) unlike LX-10, LX-07, and PBX-9501. The difference in deflagration behavior is attributed to the nature of the binder/plasticizer alone or in conjunction with the volume of binder present in PBXN-9.

  20. Targets for the National Ignition Campaign

    Science.gov (United States)

    Atherton, L. J.

    2008-05-01

    The National Ignition Facility (NIF) is a 192 beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) for performing inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. When completed in 2009, NIF will be able to produce 1.8 MJ, 500 TW of ultraviolet light for target experiments that will create conditions of extreme temperatures (>108 K), pressures (10 GBar) and matter densities (>100 g/cm3). A detailed program called the National Ignition Campaign (NIC) has been developed to enable ignition experiments in 2010, with the goal of producing fusion ignition and burn of a deuterium-tritium (DT) fuel mixture in millimeter-scale target capsules. The first of the target experiments leading up to these ignition shots will begin in 2008. The targets for the NIC are both complex and precise, and are extraordinarily demanding in materials fabrication, machining, assembly, cryogenics and characterization. The DT fuel is contained in a 2-millimeter-diameter graded copper/beryllium or CH shell. The 75-μm-thick cryogenic ice DT fuel layer is formed to sub-micron uniformity at a temperature of approximately 18 Kelvin. The capsule and its fuel layer sit at the center of a gold/depleted uranium 'cocktail' hohlraum. Researchers at LLNL have teamed with colleagues at General Atomics to lead the development of the technologies, engineering design and manufacturing infrastructure necessary to produce these demanding targets. We are also collaborating with colleagues at the Laboratory for Laser Energetics (LLE) at the University of Rochester in DT layering, and at Fraunhofer in Germany in nano-crystalline diamond as an alternate ablator to Beryllium and CH. The Beryllium capsules and cocktail hohlraums are made by physical vapor deposition onto sacrificial mandrels. These coatings must have high density (low porosity), uniform microstructure, low oxygen content and low permeability. The ablator

  1. 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.)

  2. Fusion core start-up, ignition and burn simulations of reversed-field pinch (RFP) reactors

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Yuh-Yi

    1988-01-01

    A transient reactor simulation model is developed to investigate and simulate the start-up, ignition and burn of a reversed-field pinch reactor. The simulation is based upon a spatially averaged plasma balance model with field profiles obtained from MHD quasi-equilibrium analysis. Alpha particle heating is estimated from Fokker-Planck calculations. The instantaneous plasma current is derived from a self-consistent circuit analysis for plasma/coil/eddy current interactions. The simulation code is applied to the TITAN RFP reactor design which features a compact, high-power-density reversed-field pinch fusion system. A contour analysis is performed using the steady-state global plasma balance. The results are presented with contours of constant plasma current. A saddle point is identified in the contour plot which determines the minimum value of plasma current required to achieve ignition. An optimized start-up to ignition and burn path can be obtained by passing through the saddle point. The simulation code is used to study and optimize the start-up scenario. In the simulations of the TITAN RFP reactor, the OH-driven superconducting EF coils are found to deviate from the required equilibrium values as the induced plasma current increases. This results in the modification of superconducting EF coils and the addition of a set of EF trim coils. The design of the EF coil system is performed with the simulation code subject to the optimization of trim-coil power and current. In addition, the trim-coil design is subject to the constraints of vertical-field stability index and maintenance access. A power crowbar is also needed to prevent the superconducting EF coils from generating excessive vertical field. A set of basic results from the simulation of TITAN RFP reactor yield a picture of RFP plasma operation in a reactor. Investigations of eddy current are also presented. 145 refs., 37 figs., 2 tabs.

  3. Standard Molded Composite Rocket Pyrogen Igniter - A progress report

    Science.gov (United States)

    Lucy, M. H.

    1978-01-01

    The pyrogen igniter has the function to furnish a controlled, high temperature, high pressure gas to ignite solid propellant surfaces in a rocket motor. Present pyrogens consist of numerous inert components. The Standard Molded Pyrogen Igniter (SMPI) consists of three basic parts, a cap with several integrally molded features, an ignition pellet retainer plate, and a tube with additional integrally molded features. A description is presented of an investigation which indicates that the SMPI concept is a viable approach to the design and manufacture of pyrogen igniters for solid propellant rocket motors. For some applications, combining the structural and thermal properties of molded composites can result in the manufacture of lighter assemblies at considerable cost reduction. It is demonstrated that high strength, thin walled tubes with high length to diameter ratios can be fabricated from reinforced plastic molding compound using the displacement compression process.

  4. Ignition of magnetic deflagration in Mn12 acetate

    Science.gov (United States)

    McHugh, Sean; Jaafar, R.; Sarachik, M. P.; Myasoedov, Y.; Finkler, A.; Shtrikman, H.; Zeldov, E.; Bagai, R.; Christou, G.

    2008-03-01

    We study the conditions for the ignition of two types of magnetic avalanches in the molecular magnet Mn12-acetate corresponding to the major species and a fast-relaxing minor species. The minor component, which has a lower anisotropy barrier, exists in these crystals at the level of 5-7%. The ignition temperatures are measured using small (30 x30 μm^2) Ge thermometers. In addition, the magnetization dynamics are measured using an array of Hall sensors of comparable size. Various aspects of the ignition will be discussed, including: the reduction of the ignition threshold due to quantum tunneling, the catalytic effect of the minor species, and the shift of the ignition point as a function of external magnetic field. The work at City College was supported by NSF grant DMR-00451605. E. Z. acknowledges the support of the Israel Ministry of Science, Culture and Sports. Support for G. C. was provided by NSF grant CHE-0414555.

  5. Assessment of Potential for Ion Driven Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Logan, B. Grant; Bangerter, Roger O.; Callahan, Debra A.; Tabak,Max; Roth, Markus; Perkins, L. John; Caporaso, George

    2005-05-01

    Critical issues and ion beam requirements are explored for fast ignition using ion beams to provide fuel compression using indirect drive and to provide separate short pulse ignition heating using direct drive. Several ion species with different hohlraum geometries are considered for both accelerator-produced and laser-produced ion ignition beams. Ion-driven fast ignition targets are projected to have modestly higher gains than with conventional heavy-ion fusion, and may offer some other advantages for target fabrication and for use of advanced fuels. However, much more analysis and experiments are needed before conclusions can be drawn regarding the feasibility for meeting the ion beam transverse and longitudinal emittances, focal spots, pulse lengths, and target stand-off distances required for ion-driven fast ignition.

  6. Assessment of Potential for Ion Driven Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Logan, B. Grant; Bangerter, Roger O.; Callahan, Debra A.; Tabak, Max; Roth, Markus; Perkins, L. John; Caporaso, George

    2004-12-01

    Critical issues and ion beam requirements are explored for fast ignition using ion beams to provide fuel compression using indirect drive and to provide separate short pulse ignition heating using direct drive. Several ion species with different hohlraum geometries are considered for both accelerator-produced and laser-produced ion ignition beams. Ion-driven fast ignition targets are projected to have modestly higher gains than with conventional heavy-ion fusion, and may offer some other advantages for target fabrication and for use of advanced fuels. However, much more analysis and experiments are needed before conclusions can be drawn regarding the feasibility for meeting the ion beam transverse and longitudinal emittances, focal spots, pulse lengths, and target standoff distances required for ion-driven fast ignition.

  7. 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.

  8. 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%.

  9. Fast start-up of microchannel fuel processor integrated with an igniter for hydrogen combustion

    Science.gov (United States)

    Ryi, Shin Kun; Park, Jong Soo; Cho, Song Ho; Kim, Sung Hyun

    A Pt-Zr catalyst coated FeCrAlY mesh is introduced into the combustion outlet conduit of a newly designed microchannel reactor (MCR) as an igniter of hydrogen combustion to decrease the start-up time. The catalyst is coated using a wash-coating method. After installing the Pt-Zr/FeCrAlY mesh, the reactor is heated to its running temperature within 1 min with hydrogen combustion. Two plate-type heat-exchangers are introduced at the combustion outlet and reforming outlet conduits of the microchannel reactor in order to recover the heat of the combustion gas and reformed gas, respectively. Using these heat-exchangers, methane steam reforming is carried out with hydrogen combustion and the reforming capacity and energy efficiency are enhanced by up to 3.4 and 1.7 times, respectively. A compact fuel processor and fuel-cell system using this reactor concept is expected to show considerable advancement.

  10. Laser Ignition of pyrotechnics - effects of wavelength, composition and confinement

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Sheikh Rafi; Russell, David Anthony [Department of Environmental and Ordnance Systems, Cranfield University, Royal Military College of Science, Shrivenham, Swindon, Wiltshire SN6 8LA (United Kingdom)

    2005-04-01

    Ignition tests were carried out using three different laser systems and three different pyrotechnic compositions. Pyrotechnic materials investigated are: sulfur/charcoal/potassium nitrate based composition (gunpowder, GP), Shellac binder-based boron/potassium nitrate composition (SR 44) and acaroid resin binder based magnesium/potassium nitrate composition (SR 371C). The laser sources were the multimode output from an Ar-ion laser ({lambda}=500 nm average), a high-power commercial diode laser ({lambda}=784 nm) and a small laser diode operating at around the same wavelength but controlled by a customized electronic circuitry. Lasers operating in the visible wavelength range provided more reproducible and quicker ignition than the infrared output from the diode lasers. It was found that unconfined gunpowder exhibits more reproducible ignition for both the visible and the infrared wavelengths compared to the other two compositions. The composition based on magnesium, SR 371C appeared to be very sensitive to laser intensity variations and gave erratic and therefore, irreproducible ignition delay times. The threshold laser energies to initiate reproducible ignition for the different wavelengths were measured and ignition maps were constructed. From these maps, the required laser power density for any value of the ignition delay time, i.e. laser energy density was determined. Tests were also conducted on gunpowder samples, partially confined in a modified pyrogen igniter capsule and a small laser diode. The diode was operated in single pulse mode using a current surge, which was much higher than the recommended value for CW operation. This provided 1 W pulses at the end of a 1 mm diameter fiber optic cable and caused reproducible ignition in the semi-confined pyrotechnic bed within the capsule. The threshold ignition energy under semi-confined conditions was found to be substantially less than that required in the unconfined environment under similar experimental

  11. Polar direct drive: Proof-of-principle experiments on OMEGA and prospects for ignition on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Craxton, R.S.; Marshall, F.J.; Bonino, M.J.; Epstein, R.; McKenty, P.W.; Skupsky, S.; Delettrez, J.A.; Igumenshchev, I.V.; Jacobs-Perkins, D.W.; Knauer, J.P.; Marozas, J.A.; Radha, P.B.; Seka, W.

    2005-04-15

    Polar direct drive (PDD) shows promise for achieving direct-drive ignition while the National Ignition Facility (NIF) is initially configured for indirect drive. Experiments have been carried out using 40 repointed beams of the 60-beam OMEGA laser system to approximate the NIF PDD configuration.

  12. The Xanthomonas campestris pv. vesicatoria citH gene is expressed early in the infection process of tomato and is positively regulated by the TctDE two-component regulatory system.

    Science.gov (United States)

    Tamir-Ariel, Dafna; Rosenberg, Tally; Burdman, Saul

    2011-01-01

    Xanthomonas campestris pv. vesicatoria (Xcv) is the causal agent of bacterial spot disease of tomato and pepper. Previously, we have reported the adaptation of a recombinase- or resolvase-based in vivo expression technology (RIVET) approach to identify Xcv genes that are specifically induced during its interaction with tomato. Analysis of some of these genes revealed that a citH (citrate transporter) homologous gene contributes to Xcv virulence on tomato. Here, we demonstrate that the citH product indeed facilitates citrate uptake by showing the following: citH is specifically needed for Xcv growth in citrate, but not in other carbon sources; the citH promoter is specifically induced by citrate; and the concentration of citrate from tomato leaf apoplast is considerably reduced following growth of the wild-type and a citH-complemented strain, but not the citH mutant. We also show that, in the Xcv-tomato interaction, the promoter activity of the citH gene is induced as early as 2.5h after Xcv is syringe infiltrated into tomato leaves, and continues to be active for at least 96h after inoculation. We identified an operon containing a two-component regulatory system homologous to tctD/tctE influencing citH expression in Xcv, as well as its heterologous expression in Escherichia coli. The expression of hrp genes does not seem to be affected in the citH mutant, and this mutant cannot be complemented for growth in planta when co-inoculated with the wild-type strain, indicating that citrate uptake in the apoplast is important for the virulence of Xcv.

  13. Compact Dexterous Robotic Hand

    Science.gov (United States)

    Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)

    2001-01-01

    A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

  14. Design and modeling of ignition targets for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Haan, S.W.; Pollaine, S.M.; Lindl, J.D.; Suter, L.J.; Berger, R.L.; Powers, L.V.; Alley, W.E.; Amendt, P.A.; Futterman, J.A.; Levedahl, W.K.; Rosen, M.D.; Rowley, D.P.; Sacks, R.A.; Shestakov, A.I.; Strobel, G.L.; Tabak, M.; Weber, S.V.; Zimmerman, G.B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Krauser, W.J.; Wilson, D.C.; Coggeshall, S.V.; Harris, D.B.; Hoffman, N.M.; Wilde, B.H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1995-06-01

    Several targets are described that in simulations give yields of 1--30 MJ when indirectly driven by 0.9--2 MJ of 0.35 {mu}m laser light. The article describes the targets, the modeling that was used to design them, and the modeling done to set specifications for the laser system in the proposed National Ignition Facility. Capsules with beryllium or polystyrene ablators are enclosed in gold hohlraums. All the designs utilize a cryogenic fuel layer; it is very difficult to achieve ignition at this scale with a noncryogenic capsule. It is necessary to use multiple bands of illumination in the hohlraum to achieve sufficiently uniform x-ray irradiation, and to use a low-{ital Z} gas fill in the hohlraum to reduce filling of the hohlraum with gold plasma. Critical issues are hohlraum design and optimization, Rayleigh--Taylor instability modeling, and laser--plasma interactions.

  15. Preparing for polar-drive ignition on the National Ignition Facility

    Directory of Open Access Journals (Sweden)

    McKenty P.W.

    2013-11-01

    Full Text Available The implementation of polar drive (PD at the National Ignition Facility (NIF will enable the execution of direct-drive implosions while the facility is configured for x-ray drive. The Laboratory for Laser Energetics (LLE, in collaboration with LLNL, LANL and GA, is implementing PD on the NIF. LLE has designed and participates in the use of PD implosions for diagnostic commissioning on the NIF. LLE has an active experimental campaign to develop PD in both warm and cryogenic target experiments on OMEGA. LLE and its partners are developing a Polar Drive Project Execution Plan, which will provide a detailed outline of the requirements, resources, and timetable leading to PD-ignition experiments on the NIF.

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

    Directory of Open Access Journals (Sweden)

    Stelmasiak Zdzisław

    2014-10-01

    Full Text Available 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 the tests on spark- ignition and self- ignition engines fed with two fuels: petrol and methanol or diesel oil and methanol, respectively. Te tests were carried out on a 1100 MPI Fiat four- cylinder engine with multi-point injection and a prototype collector fitted with additional injectors in each cylinder. Te other tested engine was a SW 680 six- cylinder direct- injection diesel engine. Influence of a methanol addition on basic operational parameters of the engines and exhaust gas toxicity were analyzed. Te tests showed a favourable influence of methanol on combustion process of traditional fuels and on some operational parameters of engines. An addition of methanol resulted in a distinct rise of total efficiency of both types of engines at maintained output parameters (maximum power and torque. In the same time a radical drop in content of hydrocarbons and nitrogen oxides in exhaust gas was observed at high shares of methanol in feeding dose of ZI (petrol engine, and 2-3 fold lower smokiness in case of ZS (diesel engine. Among unfavourable phenomena, a rather insignificant rise of CO and NOx content for ZI engine, and THC and NOx - for ZS engine, should be numbered. It requires to carry out further research on optimum control parameters of the engines. Conclusions drawn from this work may be used for implementation of bio-fuels to feeding the combustion engines.

  17. Update on ignition studies at Cea

    Energy Technology Data Exchange (ETDEWEB)

    Holstein, P.A.; Casanova, M.; Casner, A.; Cherfils, C.; Dattolo, E.; Disdier, L.; Galmiche, D.; Giorla, J.; Houry, M.; Jadaud, J.P.; Laffite, S.; Liberatore, S.; Loiseau, P.; Lours, L.; Masse, L.; Monteil, M.C.; Morice, O.; Naudy, M.; Philippe, F.; Poggi, F.; Renaud, F.; Riazuelo, G.; Saillard, Y.; Seytor, P.; Vandenboomgaerde, M.; Wagon, F. [CEA Bruyeres-le-Chatel, 91 (France)

    2007-08-15

    This article sums up the theoretical and experimental studies about ignition. Three experiments are salient this year on the Omega laser in collaboration with DOE laboratories. First, 3 cones of beams have allowed to mimic the LMJ (laser MegaJoule) configuration and to get symmetry measurements. Secondly, we have measured perturbations due to hydro-instability in CHGe planar samples with face-on and side-on radiographs. And thirdly, we have improved our nuclear diagnostics, particularly the neutron image system tested on direct drive implosions. As far as LMJ target design is concerned, we have defined a preliminary domain corresponding to the possible operation at 2{omega}. At 3 {omega} we have studied the low mode instability effects on the DT deformation (due to the laser or to the target) and on the yield. The stability is clearly improved with graded doped CH for our nominal capsule L1215. (authors)

  18. National Ignition Facility Target Design and Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Cook, R C; Kozioziemski, B J; Nikroo, A; Wilkens, H L; Bhandarkar, S; Forsman, A C; Haan, S W; Hoppe, M L; Huang, H; Mapoles, E; Moody, J D; Sater, J D; Seugling, R M; Stephens, R B; Takagi, M; Xu, H W

    2007-12-10

    The current capsule target design for the first ignition experiments at the NIF Facility beginning in 2009 will be a copper-doped beryllium capsule, roughly 2 mm in diameter with 160-{micro}m walls. The capsule will have a 75-{micro}m layer of solid DT on the inside surface, and the capsule will driven with x-rays generated from a gold/uranium cocktail hohlraum. The design specifications are extremely rigorous, particularly with respect to interfaces, which must be very smooth to inhibit Rayleigh-Taylor instability growth. This paper outlines the current design, and focuses on the challenges and advances in capsule fabrication and characterization; hohlraum fabrication, and D-T layering and characterization.

  19. National Ignition Facility wet weather construction plan

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, A N

    1998-01-01

    This report presents a wet weather construction plan for the National Ignition Facility (NIF) construction project. Construction of the NIF commenced in mid- 1997, and excavation of the site was completed in the fall. Preparations for placing concrete foundations began in the fall, and above normal rainfall is expected over the tinter. Heavy rainfall in late November impacted foundation construction, and a wet weather construction plan was determined to be needed. This wet weather constiction plan recommends a strategy, techniques and management practices to prepare and protect the site corn wet weather effects and allow construction work to proceed. It is intended that information in this plan be incorporated in the Stormwater Pollution Prevention Plan (SWPPP) as warranted.

  20. Treatment of Gait Ignition Failure with Ropinirole

    Directory of Open Access Journals (Sweden)

    Alexis N. Cohen-Oram

    2014-10-01

    Full Text Available Gait ignition failure (GIF is a syndrome characterized by hesitation or inability to initiate gait from a static position. It may occur in a variety of conditions, including normal pressure hydrocephalus, subcortical vascular disease, parkinsonian syndromes and a variety of focal lesions. Previous information on the treatment of GIF has been primarily anecdotal, but there have been a few reports of response to dopamine agonists. We report a 63-year-old man with anoxic encephalopathy who developed GIF nine years after the initial anoxic insult. The patient’s GIF responded robustly, albeit transiently, to ropinirole. MRI was unrevealing, but a positron emission tomography scan showed hypometabolism in the deep frontal ACA/MCA watershed area; this may have disconnected the basal ganglia from the motor cortex and/or interrupted dopaminergic mesocortical transmission. Our understanding of the pathophysiology and the treatment of GIF remains limited, but there may be at least a limited therapeutic role for dopamine agonists.

  1. Construction Safety for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Predmore, R

    2000-09-01

    This Construction Safety Program (CSP) for the National Ignition Facility (NIF) presents safety protocols and guidelines that management and workers shall follow to assure a safe and healthful work environment. Appendix A, a separate companion document, includes further applicable environmental, safety, and health requirements for the NIF Project. Specifically this document: {sm_bullet} Defines the fundamental site safety philosophy, {sm_bullet} Identifies management roles and responsibilities, {sm_bullet} Defines core safety management processes, {sm_bullet} Identifies LLNL institutional requirements, and {sm_bullet} Defines the functional areas and facilities accrued by the program and the process for transition of facilities, functional areas, and/or systems from construction to activation. Anyone willfully or thoughtlessly disregarding standards will be subject to immediate removal from the site. Thorough job planning will help ensure that these standards are met.

  2. Auto-Ignition and Heat Release Correlations for Controlled Auto-Ignition Combustion in Gasoline Engines

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Auto-ignition and heat release correlations for controlled auto-ignition (CAI) combustion were derived from extensive in-cylinder pressure data of a four-stroke gasoline engine operating in CAI combustion mode. Abundant experiments were carried out under a wide range of air/fuel ratio,speed and residual gas fraction to ensure that the combustion correlations can be used in the entire CAI engine operation range. Furthermore, a more accurate method to compute the residual gas fraction was proposed by calculating the working fluid temperature at the exhaust valve close timing in the experiments. The heat release correlation was described in two parts, one is for the first slower heat release process at low temperature, and the other is for the second faster heat release process at high temperature. Finally the heat release correlation was evaluated on the single cylinder gasoline engine running with CAI combustion by comparing the experimental data with the 1-D engine simulation results obtained with the aid of the GT-Power simulation program. The results show that the predicted loads and ignition timings match closely with the measurements.

  3. Status Of The National Ignition Campaign And National Ignition Facility Integrated Computer Control System

    Energy Technology Data Exchange (ETDEWEB)

    Lagin, L; Brunton, G; Carey, R; Demaret, R; Fisher, J; Fishler, B; Ludwigsen, P; Marshall, C; Reed, R; Shelton, R; Townsend, S

    2011-03-18

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that will contains a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for multiple experimental diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. NIF's laser beams are designed to compress fusion targets to conditions required for thermonuclear burn. NIF is operated by the Integrated Computer Control System (ICCS) in an object-oriented, CORBA-based system distributed among over 1800 frontend processors, embedded controllers and supervisory servers. In the fall of 2010, a set of experiments began with deuterium and tritium filled targets as part of the National Ignition Campaign (NIC). At present, all 192 laser beams routinely fire to target chamber center to conduct fusion and high energy density experiments. During the past year, the control system was expanded to include automation of cryogenic target system and over 20 diagnostic systems to support fusion experiments were deployed and utilized in experiments in the past year. This talk discusses the current status of the NIC and the plan for controls and information systems to support these experiments on the path to ignition.

  4. 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

  5. Bridge Wire Electric Ignition Drive Circuits Design%桥丝电点火器的驱动电路设计∗

    Institute of Scientific and Technical Information of China (English)

    张宪国; 曹红松; 赵捍东; 白松

    2015-01-01

    Pulse jet engines are often ignited by gunpowder wrapped bridge wire electric igniter and widely used in aircraft attitude control. The electric igniter needs short-pulse current driving for rapid initiation. In this paper,opto-isolated constant current source and capacitor discharge mode driving circuits are designed for the demand of micro-bridge wire electric igniter. Two kinds of detonating circuit designs implemente the ignition driving of brige wire e-lectric igniter wtih resistance fluctuations. The constant current source mode is capable of long storage life,compact spatial structure and high safety, and the reservoir capacitor mode demonstrates high energy efficiency and fast-acting for quick initiation. Two methods provide reference designs for the pulse jet engines of different engineering requirements.%用于飞行器姿态控制的脉喷发动机常采用火药包裹的桥丝电点火器进行点火,电点火器需要短时脉冲电流驱动。本文针对微小型桥丝电点火器驱动需求,设计了光耦隔离恒流源方式及电容储能脉冲放电驱动电路,均实现了对阻值波动桥丝电点火器的点火驱动。试验证明,光耦隔离恒流源方式可靠性高,安全稳定,电容储能放电方式效率高、作用迅速。该两种设计方法可为脉喷发动机的工程实践提供参考。

  6. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  7. Compact Grism Spectrometer

    Science.gov (United States)

    Teare, S. W.

    2003-05-01

    Many observatories and instrument builders are retrofitting visible and near-infrared spectrometers into their existing imaging cameras. Camera designs that reimage the focal plane and have the optical filters located in a pseudo collimated beam are ideal candidates for the addition of a spectrometer. One device commonly used as the dispersing element for such spectrometers is a grism. The traditional grism is constructed from a prism that has had a diffraction grating applied on one surface. The objective of such a design is to use the prism wedge angle to select the desired "in-line" or "zero-deviation" wavelength that passes through on axis. The grating on the surface of the prism provides much of the dispersion for the spectrometer. A grism can also be used in a "constant-dispersion" design which provides an almost linear spatial scale across the spectrum. In this paper we provide an overview of the development of a grism spectrometer for use in a near infrared camera and demonstrate that a compact grism spectrometer can be developed on a very modest budget that can be afforded at almost any facility. The grism design was prototyped using visible light and then a final device was constructed which provides partial coverage in the near infrared I, J, H and K astronomical bands using the appropriate band pass filter for order sorting. The near infrared grism presented here provides a spectral resolution of about 650 and velocity resolution of about 450 km/s. The design of this grism relied on a computer code called Xspect, developed by the author, to determine the various critical parameters of the grism. This work was supported by a small equipment grant from NASA and administered by the AAS.

  8. Robustness studies of NIF ignition targets in two dimensions

    Science.gov (United States)

    Clark, Daniel

    2007-11-01

    Inertial confinement fusion capsules are critically dependent on the integrity of their hot spots to ignite. At the time of ignition, only a certain fractional perturbation of the nominally spherical hot spot boundary can be tolerated and the capsule still achieve ignition. The degree to which the expected hot spot perturbation in any given capsule design is less than this maximum tolerable perturbation is a measure of the ignition margin or robustness of that design. Moreover, since there will inevitably be uncertainties in the initial character and implosion dynamics of any given capsule, all of which can contribute to the eventual hot spot perturbation, quantifying the robustness of that capsule against a range of parameter variations is an important consideration in the capsule design. Here, the robustness of the 300 eV indirect drive target design for the National Ignition Facility (NIF) [J. D. Lindl, et. al., Phys. Plasmas 11, 339 (2004)] is studied in the parameter space of inner ice roughness, implosion velocity, and capsule scale. A suite of two thousand two-dimensional simulations, run with the radiation hydrodynamics code Lasnex, is used as the data base for the study. For each scale, an ignition region in the two remaining variables is identified and the ``ignition cliff'' is mapped. In accordance with the theoretical arguments of W. K. Levedahl and J. D. Lindl [Nucl. Fusion 37, 165 (1997)] and R. Kishony and D. Shvarts [Phys. Plasmas 8, 4925 (2001)], the location of this cliff is fitted to a power law of the capsule implosion velocity and scale. It is found that the cliff can be quite well represented in this power law form, and, using this scaling law, an assessment of the overall (one- and two-dimensional) ignition margin of the design can be made. The effect on the ignition margin of an increase or decrease in the density of the target fill gas is also assessed.

  9. The National Ignition Facility: The Path to Ignition, High Energy Density Science and Inertial Fusion Energy

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E

    2011-03-25

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is a Nd:Glass laser facility capable of producing 1.8 MJ and 500 TW of ultraviolet light. This world's most energetic laser system is now operational with the goals of achieving thermonuclear burn in the laboratory and exploring the behavior of matter at extreme temperatures and energy densities. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in the interiors of planetary and stellar environments. On September 29, 2010, NIF performed the first integrated ignition experiment which demonstrated the successful coordination of the laser, the cryogenic target system, the array of diagnostics and the infrastructure required for ignition. Many more experiments have been completed since. In light of this strong progress, the U.S. and the international communities are examining the implication of achieving ignition on NIF for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a 10% electrical-optical efficiency laser, as well as further advances in large-scale target fabrication, target injection and tracking, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in 10- to 15-years. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Energy (LIFE) baseline design and examining various technology choices for LIFE power plant This paper will describe the unprecedented experimental capabilities of the NIF, the results achieved so far on the path toward ignition, the start of fundamental science experiments and plans to transition NIF to an international user facility

  10. A study on spontaneous ignition of bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Xin-Rui Li; Hiroshi Koseki; Yusaku Iwata [National Research Institute of Fire and Disaster, Tokyo (Japan)

    2009-07-01

    The thermal properties of four bituminous coals were studied using isothermal and temperature-programmed calorimeters, such as a differential thermal analysis, a heat flux calorimeter C80 and an thermal activity monitor (TAM-III). The corresponding spontaneous ignition was measured in an adiabatic spontaneous ignition tester. It was found that there were weak exothermic activities in bituminous coal at 50-100 {sup o}C and meanwhile carbon monoxide and carbon dioxide was generated. These thermal behaviors are responsible for the self heating from 50{sup o}C and spontaneous ignition at 80{sup o}C. 15 refs., 7 figs., 5 tabs.

  11. Shock Timing experiments on the National Ignition Facility

    Science.gov (United States)

    Celliers, P. M.; Boehly, T. R.; Robey, H. F.; Datte, P. S.; Bowers, M. W.; Krauter, K. G.; Frieders, G.; Ross, G. F.; Jackson, J. L.; Olson, R. E.; Munro, D. H.; Nikroo, A.; Kroll, J. J.; Horner, J. B.; Hamza, A. V.; Bhandarkar, S. D.; Gibson, C. R.; Eggert, J. H.; Smith, R. F.; Park, H.-S.; Young, B. K.; Hsing, W. W.; Collins, G. W.; Landen, O. L.; Meyerhofer, D. D.

    2011-06-01

    Experiments are proceeding to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility. These experiments use a modified cryogenic hohlraum geometry designed to match the performance of ignition hohlraums. The targets employ a re-entrant Au cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with VISAR (Velocity Interferometer System for Any Reflector). The results of these measurements will be used to set the pulse shape for ignition capsule implosions to follow. Prepared by LLNL under Contract DE-AC52-07NA27344.

  12. A study on spontaneous ignition of bituminous coal

    Directory of Open Access Journals (Sweden)

    Li Xin-Rui

    2009-01-01

    Full Text Available The thermal properties of four bituminous coals were studied using isothermal and temperature-programmed calorimeters, such as a differential thermal analysis, a heat flux calorimeter C80 and an thermal activity monitor (TAM-III. The corresponding spontaneous ignition was measured in an adiabatic spontaneous ignition tester. It was found that there were weak exothermic activities in bituminous coal at 50-100°C and meanwhile carbon monoxide and carbon dioxide was generated. These thermal behaviors are responsible for the self heating from 50°C and spontaneous ignition at 80°C.

  13. Le travail du récit sur les relations de care : littérature et sociologie

    Directory of Open Access Journals (Sweden)

    Laura Marzi

    2016-03-01

    Full Text Available A partir de la perspective féministe du care, cet article propose une analyse mettant en regard la façon dont les approches littéraire et ethnographique parviennent à représenter la position subalterne de la travailleuse du care et la relation de care entre l’employée et l’employeuse domestique. Le travail de la littérature est étudié à partir du roman La Porte de Magda Szabò. Dans cet ouvrage, le déclenchement de l’histoire est la volonté de la part de l’écrivaine de réparer sa trahison envers l’employée domestique Emerenc. Cette réparation consiste pour Szabò dans l’écriture du récit de l’histoire de la vie d’Emerenc, qui devient ainsi visible. On se demande ensuite si cette réparation passe à travers une héroïsation du personnage de la travailleuse. Dans les romans de care les femmes care-givers occupent la scène principale: elles sont des héroïnes, non pas dans le sens de l’héroïsme universel masculin, mais de celui qui émerge des récits de care au prisme du genre. L’approche ethnographique est considérée à partir du livre de Caroline Ibos Qui gardera nos enfants? Cette enquête de terrain sur les relations entre nounous ivoiriennes et employeuses, en région parisienne laisse une large place aux paroles des nounous. Elle montre comment l’invisibilisation de la travailleuse du care répond à la nécessité pour l’employeuse de garder intact l’ordre symbolique de son appartement en dépit du passage quotidien de la femme étrangère.

  14. Compact, Airborne Multispecies Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase I proposal seeks to develop a compact mid-infrared laser spectrometer to benefit Earth science research activities. To...

  15. Countably determined compact abelian groups

    CERN Document Server

    Dikranjan, Dikran

    2008-01-01

    For an abelian topological group G let G^* be the dual group of all continuous characters endowed with the compact open topology. A subgroup D of G determines G if the restriction homomorphism G^* --> D^* of the dual groups is a topological isomorphism. Given a scattered compact subset X of an infinite compact abelian group G such that |X|compact abelian group determined by its countable subgroup must be metrizable. This gives a negative answer to questions of Comfort, Hernandez, Macario, Raczkowski and Trigos-Arrieta, as well as provides short proofs of main results established in three manuscripts by these authors.

  16. Compact energy conversion module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project delivers a compact vibration-based Energy Conversion Module (ECM) that powers sensors for purposes like structural health monitoring (SHM). NASA...

  17. Compact, Ultrasensitive Formaldehyde Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase II proposal seeks to develop a compact UV laser ?based sensor for Earth science and planetary atmosphere exploration....

  18. What Is Business's Social Compact?

    Science.gov (United States)

    Avishai, Bernard

    1994-01-01

    Under the "new" social compact, businesses must focus on continuous learning and thus have both an obligation to support teaching and an opportunity to profit from it. Learning organizations must also be teaching organizations. (SK)

  19. Relating the octane numbers of fuels to ignition delay times measured in an ignition quality tester (IQT)

    KAUST Repository

    Naser, Nimal

    2016-09-21

    A methodology for estimating the octane index (OI), the research octane number (RON) and the motor octane number (MON) using ignition delay times from a constant volume combustion chamber with liquid fuel injection is proposed by adopting an ignition quality tester. A baseline data of ignition delay times were determined using an ignition quality tester at a charge pressure of 21.3 bar between 770 and 850 K and an equivalence ratio of 0.7 for various primary reference fuels (PRFs, mixtures of isooctane and n-heptane). Our methodology was developed using ignition delay times for toluene reference fuels (mixtures of toluene and n-heptane). A correlation between the OI and the ignition delay time at the initial charge temperature enabled the OI of non-PRFs to be predicted at specified temperatures. The methodology was validated using ignition delay times for toluene primary reference fuels (ternary mixtures of toluene, iso-octane, and n-heptane), fuels for advanced combustion engines (FACE) gasolines, and certification gasolines. Using this methodology, the RON, the MON, and the octane sensitivity were estimated in agreement with values obtained from standard test methods. A correlation between derived cetane number and RON is also provided. (C) 2016 Elsevier Ltd. All rights reserved.

  20. Ignition time of self-propagating high-temperature synthesis by laser

    Institute of Scientific and Technical Information of China (English)

    陈森昌; 迟彦惠; 史玉升; 黄树槐

    2002-01-01

    The ignition of self-propagating high-temperature synthesis (SHS) by a laser beam has very well application, but there is lack in study on the ignition process. In order to search the rule of ignition process with laser beam, ignition time of SHS was studied in detail. First one dimension ignition model was introduced: burning is the process in which one layer is ignited by next layer. Then according to Fourier conduction equation, an equation used to calculate the ignition time was deduced. Finally a series of tests were made to verify the equation. The results prove that the change of the parameters in test agrees well with the equation.

  1. 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...

  2. Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

    KAUST Repository

    Alfazazi, Adamu

    2016-08-10

    The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate the ignition delay of n-dodecane and n-heptane in a constant volume combustion chamber (CVCC), which is archived in the engine combustion network (ECN) library (http://www.ca.sandia.gov/ecn). A detailed chemical kinetic model for gasoline surrogates from the Lawrence Livermore National Laboratory (LLNL) was utilized for the simulation of n-heptane and isooctane. Additional simulations were performed using an optimized gasoline surrogate mechanism from RWTH Aachen University. Validations of the simulated data were also performed with experimental results from an IQT at KAUST. For simulation of n-dodecane in the CVCC, two n-dodecane kinetic models from the literature were utilized. The primary aim of this study is to test the ability of TSL to replicate ignition timings in the IQT and the CVCC. The agreement between the model and the experiment is acceptable except for isooctane in the IQT and n-heptane and n-dodecane in the CVCC. The ability of the simulations to replicate observable trends in ignition delay times with regard to changes in ambient temperature and pressure allows the model to provide insights into the reactions contributing towards ignition. Thus, the TSL model was further employed to investigate the physical and chemical processes responsible for controlling the overall ignition under various conditions. The effects of exothermicity, ambient pressure, and ambient oxygen concentration on first stage ignition were also studied. Increasing ambient pressure and oxygen concentration was found to shorten the overall ignition delay time, but does not affect the timing of the first stage ignition. Additionally, the temperature at the end of the first stage ignition was found to increase at higher ambient pressure

  3. 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.)

  4. Ignition of Isomers of Pentane: An Experimental and Kinetic Modeling Study

    Science.gov (United States)

    2000-08-04

    diesel engines [26,27], and ignition under homogeneous charge compres- sion ignition ( HCCI ) conditions [26,28]. Kinetic modeling shows that the isomers of...Introduction Hydrocarbon ignition is important in many prac- tical combustion systems, including internal com- bustion engines , detonations, pulse combustors...tem- peratures are similar to those in automotive engines during diesel ignition and end-gas autoignition in spark-ignition engines . The RCM provides

  5. 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

    2010-01-01

    the 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]....

  6. Propellant Flow Actuated Piezoelectric Rocket Engine Igniter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Under a Phase 1 effort, IES successfully developed and demonstrated a spark ignition concept where propellant flow drives a very simple fluid mechanical oscillator...

  7. Propellant Flow Actuated Piezoelectric Rocket Engine Igniter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spark ignition of a bi-propellant rocket engine is a classic, proven, and generally reliable process. However, timing can be critical, and the control logic,...

  8. Physical Improvements in Exciter/Igniter Units Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project consists of developing a prototype exciter/igniter unit that can operate to a subset of expected flight performance requirements. The main focus...

  9. Frictionally induced ignition processes in drop and skid tests

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Peter [Los Alamos National Laboratory; Parker, Gary [Los Alamos National Laboratory; Novak, Alan [Los Alamos National Laboratory

    2010-01-01

    The standard LANL/Pantex drop and skid tests rely on subjective assessment of reaction violence to quantify the response of the charge, and completely miss nonpropagating hot-spot ignition sites. Additionally, large variations in test results have been observed, which we propose is due to a misunderstanding of the basic physical processes that lead to threshold ignition in these tests. The tests have been redesigned to provide control of these mechanisms and to permit direct observation of hot spots at the impact site, allowing us to follow the progression of the outcome as the drop height and ignition source density are varied. The results confirm that frictional interactions between high-melting-point solids are the dominant ignition mechanism, not just at the threshold, but in fact at all realistic drop heights.

  10. cit et éthique dans l’écriture du voyage de Camilo José Cela

    Directory of Open Access Journals (Sweden)

    Carmen Dubois

    2005-04-01

    Full Text Available Au delà de la simple narration d’un parcours spatial, les récits de voyage de Camilo José Cela ont une forte dimension éthique. Le vagabondage célien est la manifestation d’une certaine vision du monde et de l’homme construite autour de trois notions clés: renoncement, vitalité et utopie. Le voyageur se veut ainsi à l’image de cet idéal célien ; sa vie est réglée par une déontologie précise : le détachement, la solitude, la communion avec la nature, l’éloignement de la ville et l’attachement au monde rural sont les plus manifestes. En dernière instance, le vagabondage, éthique exigeante et réservée à quelque êtres d’exception, est la voie qui mène à la liberté et au bonheur.

  11. Romanzo Criminale : la série dans un récit transmédial

    Directory of Open Access Journals (Sweden)

    Marta Boni

    2011-04-01

    Full Text Available Cet article analyse la série italienne Romanzo Criminale à la lumière de la notion de quality soap, et essayant de rendre compte d’un nouveau phénomène culturel et social qui est celui du récit transmédial. Cette étude a été effectuée en alliant une analyse narratologique de la structure de la série à une enquête ethnographique expérimentale concernant les modalités de la réception, notamment dans les espaces en ligne consacrés aux discussions et aux pratiques parodiques, dans le contexte de la « culture participative ».This paper analyzes the Italian TV series Romanzo Criminale through the concept of quality soap, trying to describe a new cultural and social phenomenon that is transmedia storytelling. This study has been developed combining an analysis of the show’s narratological structure with an experimental ethnographic study of its reception, with an emphasis on online spaces dedicated to discussion and parodic practices, in the context of the "participatory culture".

  12. The DCR protein TTC3 affects differentiation and Golgi compactness in neurons through specific actin-regulating pathways.

    Directory of Open Access Journals (Sweden)

    Gaia Elena Berto

    Full Text Available In neuronal cells, actin remodeling plays a well known role in neurite extension but is also deeply involved in the organization of intracellular structures, such as the Golgi apparatus. However, it is still not very clear which mechanisms may regulate actin dynamics at the different sites. In this report we show that high levels of the TTC3 protein, encoded by one of the genes of the Down Syndrome Critical Region (DCR, prevent neurite extension and disrupt Golgi compactness in differentiating primary neurons. These effects largely depend on the capability of TTC3 to promote actin polymerization through signaling pathways involving RhoA, ROCK, CIT-N and PIIa. However, the functional relationships between these molecules differ significantly if considering the TTC3 activity on neurite extension or on Golgi organization. Finally, our results reveal an unexpected stage-dependent requirement for F-actin in Golgi organization at different stages of neuronal differentiation.

  13. Advanced laser particle accelerator development at LANL: from fast ignition to radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Flippo, Kirk A [Los Alamos National Laboratory; Gaillard, Sandrine A [Los Alamos National Laboratory; Offermann, D T [Los Alamos National Laboratory; Cobble, J A [Los Alamos National Laboratory; Schmitt, M J [Los Alamos National Laboratory; Gautier, D C [Los Alamos National Laboratory; Kwan, T J T [Los Alamos National Laboratory; Montgomery, D S [Los Alamos National Laboratory; Kluge, Thomas [FZD-GERMANY; Bussmann, Micheal [FZD-GERMANY; Bartal, T [UCSD; Beg, F N [UCSD; Gall, B [UNIV OF MISSOURI; Geissel, M [SNL; Korgan, G [NANOLABZ; Kovaleski, S [UNIV OF MISSOURI; Lockard, T [UNIV OF NEVADA; Malekos, S [NANOLABZ; Schollmeier, M [SNL; Sentoku, Y [UNIV OF NEVADA; Cowan, T E [FZD-GERMANY

    2010-01-01

    Laser-plasma accelerated ion and electron beam sources are an emerging field with vast prospects, and promise many superior applications in a variety of fields such as hadron cancer therapy, compact radioisotope generation, table-top nuclear physics, laboratory astrophysics, nuclear forensics, waste transmutation, SN M detection, and inertial fusion energy. LANL is engaged in several projects seeking to develop compact high current and high energy ion and electron sources. We are especially interested in two specific applications: ion fast ignition/capsule perturbation and radiation oncology in conjunction with our partners at the ForschungsZentrum Dresden-Rossendorf (FZD). Laser-to-beam conversion efficiencies of over 10% are needed for practical applications, and we have already shown inherent etliciencies of >5% from flat foils, on Trident using only a 5th of the intensity and energy of the Nova Petawatt. With clever target designs, like structured curved cone targets, we have also been able to achieve major ion energy gains, leading to the highest energy laser-accelerated proton beams in the world. These new target designs promise to help usher in the next generation of particle sources realizing the potential of laser-accelerated beams.

  14. Advanced Laser Particle Accelerator Development at LANL: From Fast Ignition to Radiation Oncology

    Science.gov (United States)

    Flippo, K. A.; Gaillard, S. A.; Kluge, T.; Bussmann, M.; Offermann, D. T.; Cobble, J. A.; Schmitt, M. J.; Bartal, T.; Beg, F. N.; Cowan, T. E.; Gall, B.; Gautier, D. C.; Geissel, M.; Kwan, T. J.; Korgan, G.; Kovaleski, S.; Lockard, T.; Malekos, S.; Montgomery, D. S.; Schollmeier, M.; Sentoku, Y.

    2010-11-01

    Laser-plasma accelerated ion and electron beam sources are an emerging field with vast prospects, and promise many superior applications in a variety of fields such as hadron cancer therapy, compact radioisotope generation, table-top nuclear physics, laboratory astrophysics, nuclear forensics, waste transmutation, Special Nuclear Material (SNM) detection, and inertial fusion energy. LANL is engaged in several projects seeking to develop compact high-current and high-energy ion and electron sources. We are especially interested in two specific applications: ion fast ignition/capsule perturbation and radiation oncology. Laser-to-beam conversion efficiencies of over 10% are needed for practical applications, and we have already shown inherent efficiencies of >5% from flat foils, on Trident using only a 5th of the intensity [1] and energy of the Nova Petawatt laser [2]. With clever target designs, like structured curved cone targets, we have also been able to achieve major ion energy gains, leading to the highest energy laser-accelerated proton beams in the world [3]. These new target designs promise to help usher in the next generation of particle sources realizing the potential of laser-accelerated beams.

  15. Relationship between striatal [{sup 123}I]{beta}-CIT binding and four major clinical signs in Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Shinotoh, Hitoshi; Uchida, Yoshitaka; Ito, Hisao; Hattori, Takamichi [Chiba Univ. (Japan). School of Medicine

    2000-06-01

    We investigated the correlation between clinical severity and striatal [{sup 123}I]{beta}-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. [{sup 123}I]{beta}-CIT binding in the caudate and putamen was measured at 3 hours [V''{sub 3} (day 1)], and at 24 hours [V''{sub 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, p<0.0012) was between putamenal V''{sub 3} (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''{sub 3} (day 2) (r=-0.81, p<0.002). [{sup 123}I]{beta}-CIT SPECT is a useful marker of disease severity in PD with potential utility in the serial monitoring of disease progression. (author)

  16. Fast Ignition and Sustained Combustion of Ionic Liquids

    Science.gov (United States)

    Joshi, Prakash B. (Inventor); Piper, Lawrence G. (Inventor); Oakes, David B. (Inventor); Sabourin, Justin L. (Inventor); Hicks, Adam J. (Inventor); Green, B. David (Inventor); Tsinberg, Anait (Inventor); Dokhan, Allan (Inventor)

    2016-01-01

    A catalyst free method of igniting an ionic liquid is provided. The method can include mixing a liquid hypergol with a HAN (Hydroxylammonium nitrate)-based ionic liquid to ignite the HAN-based ionic liquid in the absence of a catalyst. The HAN-based ionic liquid and the liquid hypergol can be injected into a combustion chamber. The HAN-based ionic liquid and the liquid hypergol can impinge upon a stagnation plate positioned at top portion of the combustion chamber.

  17. Ignition and burn of a small magnetized fuel target

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, Ronald C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2012-06-01

    The crucial step for inertial confinement fusion (ICF) is ignition, which leads to sufficiently high gain to enable design of a power producing system. Thus far, this step has not been demonstrated. Magnetized targets may provide an alternative path to ignition. In addition, the 1-D calculations presented here suggest that this approach may provide the gain and other characteristics needed for a practical fusion reactor.

  18. Impact of Fast Ignition on Laser Fusion Energy Development

    Science.gov (United States)

    Mirna, Kunioki

    2016-10-01

    Reviewed are the early history of Japanese laser fusion research and the recent achievement of fast ignition research at Institute of Laser Engineering (ILE), Osaka University. After the achievement of high density compression at Osaka University, LLE of University Rochester, and LLNL, the critical issue of Inertial Fusion Energy (IFE) research became the formation of hot spark in a compressed plasma. In this lecture, the history of the fast ignition research will be reviewed and future prospects are presented.

  19. Ignition technique for an in situ oil shale retort

    Science.gov (United States)

    Cha, Chang Y.

    1983-01-01

    A generally flat combustion zone is formed across the entire horizontal cross-section of a fragmented permeable mass of formation particles formed in an in situ oil shale retort. The flat combustion zone is formed by either sequentially igniting regions of the surface of the fragmented permeable mass at successively lower elevations or by igniting the entire surface of the fragmented permeable mass and controlling the rate of advance of various portions of the combustion zone.

  20. Compact Intracloud Discharges

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David A. [Univ. of Colorado, Boulder, CO (United States)

    1998-11-01

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackboard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackboard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackboard observations. On two occasions, the ground-based systems and Blackboard even recorded emissions that were produced by the same exact events. From the ground based observations, it has been determined that TIPP events areproduced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDS, an acronym for compact intracloud discharges. During the summer of 1996, ground-based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDS. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDS were recorded from three

  1. Compactness in intuitionistic fuzzy topological spaces

    Directory of Open Access Journals (Sweden)

    S. E. Abbas

    2005-02-01

    Full Text Available We introduce fuzzy almost continuous mapping, fuzzy weakly continuous mapping, fuzzy compactness, fuzzy almost compactness, and fuzzy near compactness in intuitionistic fuzzy topological space in view of the definition of Å ostak, and study some of their properties. Also, we investigate the behavior of fuzzy compactness under several types of fuzzy continuous mappings.

  2. Mechanism of plasma ignition in electrothermal-chemical launcher

    Directory of Open Access Journals (Sweden)

    Yong Jin

    2016-04-01

    Full Text Available Plasma generator is a core component in an electrothermal-chemical (ETC launcher. Its work state directly influences the launch efficiency of a system. The interaction between plasma and propellants is a very important mechanism in ETC technology. Based on the transient radiation model and open air plasma jet experiment, the mechanism of plasma ignition process is analyzed. Results show that the surface temperature of local solid propellant grain can quickly achieve the ignition temperature under the action of early transient plasma radiation. But it needs enough time to maintain the high energy flow to make self-sustained combustion of solid propellant grains. Because of the limited space characteristics of transient radiation, the near-field propellant grains can gain enough energy by the strong transient radiation to be ignited and achieve self-sustained combustion. The far-field propellant grains mainly gain the energy by the activated particles in plasma jet to be ignited and self-sustained combustion. Experiments show that plasma jet always has a high flow velocity in the area of the cartridge. Compared with conventional ignition, the solid propellant grains can obtain more quick and uniform ignition and self-sustained combustion by this kind of ablation controlled arc (ACA plasma via energy skin effect of propellant grains, pre-heat temperature mechanism and high efficient jet diffusion.

  3. Analysis of Metallised Propellant Ignition Process under Conductive Heating

    Directory of Open Access Journals (Sweden)

    K. A. Bhaskaran

    1998-07-01

    Full Text Available Ignition of a composite aluminised propellant (AP-HTPB-Al in stagnant hot air is analysed theoretically, based on solid phase and gas phase theories. According to solid phase theory, ignition is due to reaction of the propellant in the solid phase at elevated temperatures. One-dimensional transient solid phase energy equation is solved to obtain the surface temperature profile of the propellant. By gas phase theory, an exothermic gas phase reaction, adjacent to the propellant surface, is considered responsible for the ignition. The changes in temperature and concentrations in the gas phase and the temperature profile below the propellant surface during the pre-ignition induction period are considered. Equations of energy and concentrations of reactants have been solved to obtain the species concentration and temperature profiles in the gas phase. An experimental investigation of the ignition of AP-HTPB-Al propellant is also carried out in a shock tube under end-mount conditions. Pressure and temperature ranges were 6-16 bar and 1500-3000 K, respectively. A comparison of the experimental data with predicted results shows that the ignition in an oxidizing atmosphere is by gas phase reaction, whereas in an inert atmosphere, solid phase reaction may be predominant.

  4. Mechanism of plasma ignition in electrothermal-chemical launcher

    Institute of Scientific and Technical Information of China (English)

    Yong JIN; Yan-jie NI; Hai-yuan LI; Bao-ming LI

    2016-01-01

    Plasma generator is a core component in an electrothermal-chemical (ETC) launcher. Its work state directly influences the launch efficiency of a system. The interaction between plasma and propellants is a very important mechanism in ETC technology. Based on the transient radiation model and open air plasma jet experiment, the mechanism of plasma ignition process is analyzed. Results show that the surface temperature of local solid propellant grain can quickly achieve the ignition temperature under the action of early transient plasma radiation. But it needs enough time to maintain the high energy flow to make self-sustained combustion of solid propellant grains. Because of the limited space characteristics of transient radiation, the near-field propellant grains can gain enough energy by the strong transient radiation to be ignited and achieve self-sustained combustion. The far-field propellant grains mainly gain the energy by the activated particles in plasma jet to be ignited and self-sustained combustion. Experiments show that plasma jet always has a high flow velocity in the area of the cartridge. Compared with conventional ignition, the solid propellant grains can obtain more quick and uniform ignition and self-sustained combustion by this kind of ablation controlled arc (ACA) plasma via energy skin effect of propellant grains, pre-heat temperature mechanism and high efficient jet diffusion.

  5. Controlled auto ignition of gasoline engines; Steuerung der ottomotorischen Selbstzuendung

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Christina

    2011-07-01

    Controlled Auto Ignition allows for significant efficiency gains in combination with extremely low NO{sub x} emissions and particulate matters when compared to conventional spark ignited combustion concepts. The limiting factors for controlled auto ignition are the temperature at very low loads and the pressure gradient at higher loads. Based on experiments on a single cylinder engine with fully variable valve actuators and gasoline direct injection, the contribution under consideration reports on main parameters to control the controlled auto ignition. Detailed analyses demonstrate the impact of each parameter on self-ignition and combustion. Additionally, different methods to expand the operating range of controlled auto ignition are discussed with regard to the achievable efficiency and the required effort. One important result of this contribution is a feed-forward control which coordinates the main actuating parameters and ensures the desired combustion phasing even in dynamic mode. A regression model is developed which uses the input variables air/fuel ratio, start of injection, engine speed and fuel mass to predict the combustion phasing and the indicated mean effective pressure. Inverting this model leads to the final feed-forward control which allows to separate the effects of start of injection and exhaust valve closing. In that case exhaust valve closing controls the air/fuel ratio, while start of injection corrects the lasting deviation in combustion phasing. Using the actual air/fuel ratio as an additional input parameter ensures the required combustion phasing even in dynamic mode.

  6. Ignition of pyrophoric powders: An entry-level model

    Science.gov (United States)

    Alymov, M. I.; Seplyarskii, B. S.; Gordopolova, I. S.

    2015-11-01

    Chemically prepared metal nanopowders are normally pyrophoric, i.e. are liable to ignite spontaneously on exposure to air because of high reactivity and developed specific surface. On the other side, reliable theoretical models for spontaneous self-ignition of fine dispersed powders at room temperature have not been suggested so far. A deeper insight into the mechanism of the phenomenon would shed new light on the critical conditions for self-inflammation and thus would provide some clues for optimization of the passivation of fine dispersed powders. In this work, we formulated and analyzed an entry-level model for ignition of pyrophoric powders. Analysis of such a model in terms of the ignition theory gave the following results. Depending on the width of the reaction zone, the ignition may get started in either one or two stages. The duration of each stage was evaluated by using the approximate methods of combustion theory. The parametric limits for the model applicability were derived and the influence of sample length on the ignition process was explored as well.

  7. CORONA DISCHARGE IGNITION FOR ADVANCED STATIONARY NATURAL GAS ENGINES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Paul D. Ronney

    2003-09-12

    An ignition source was constructed that is capable of producing a pulsed corona discharge for the purpose of igniting mixtures in a test chamber. This corona generator is adaptable for use as the ignition source for one cylinder on a test engine. The first tests were performed in a cylindrical shaped chamber to study the characteristics of the corona and analyze various electrode geometries. Next a test chamber was constructed that closely represented the dimensions of the combustion chamber of the test engine at USC. Combustion tests were performed in this chamber and various electrode diameters and geometries were tested. The data acquisition and control system hardware for the USC engine lab was updated with new equipment. New software was also developed to perform the engine control and data acquisition functions. Work is underway to design a corona electrode that will fit in the new test engine and be capable igniting the mixture in one cylinder at first and eventually in all four cylinders. A test engine was purchased for the project that has two spark plug ports per cylinder. With this configuration it will be possible to switch between corona ignition and conventional spark plug ignition without making any mechanical modifications.

  8. The Construction of Finer Compact Topologies

    OpenAIRE

    2005-01-01

    It is well known that each locally compact strongly sober topology is contained in a compact Hausdorff topology; just take the supremum of its topology with its dual topology. On the other hand, examples of compact topologies are known that do not have a finer compact Hausdorff topology. This led to the question (first explicitly formulated by D.E. Cameron) whether each compact topology is contained in a compact topology with respect to which all compact sets are closed. (For the obvious r...

  9. Compactly convex sets in linear topological spaces

    CERN Document Server

    Banakh, T; Ravsky, O

    2012-01-01

    A convex subset X of a linear topological space is called compactly convex if there is a continuous compact-valued map $\\Phi:X\\to exp(X)$ such that $[x,y]\\subset\\Phi(x)\\cup \\Phi(y)$ for all $x,y\\in X$. We prove that each convex subset of the plane is compactly convex. On the other hand, the space $R^3$ contains a convex set that is not compactly convex. Each compactly convex subset $X$ of a linear topological space $L$ has locally compact closure $\\bar X$ which is metrizable if and only if each compact subset of $X$ is metrizable.

  10. Sensitivity and Effect of Ignition Timing on the Performance of a Spark Ignition Engine: An Experimental and Modeling Study

    Directory of Open Access Journals (Sweden)

    A. H. Kakaee

    2011-01-01

    Full Text Available The performance of a spark ignition engine is investigated under different values of ignition advance. A two-zone burnt/unburned model with the fuel burning rate described by a Wiebe function is used for modeling in-cylinder combustion, and then experiments are carried out to validate the calculated data. By varying the ignition timing, the results of some characteristics such as power, torque, thermal efficiency, pressure, and heat release are obtained and compared. The results show that optimal power and torque are achieved at 31°CA before top dead center, and performance is decreased if this ignition timing is changed. It is also shown that the maximum thermal efficiency is accomplished when peak pressure occurs between 5 and 15°CA after top dead center.

  11. Homogeneous charge compression ignition (HCCI) - A comparison with spark ignition (SI) operation

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Magnus

    1997-08-01

    Homogeneous Charge Compression Ignition (HCCI) is the third alternative for combustion in engines. Here a homogeneous premixed charge is used as in a spark ignited engine but the charge is compressed to auto-ignition as in a diesel. The characteristics of HCCI was compared to spark ignition (SI) using a 1.6 liter single cylinder engine. Three different fuels were used; isooctane, ethanol and natural gas. HCCI could be used with all three fuels in a single cylinder engine with a fixed compression ratio. Some remarkable results were noted in the experiments. The indicated efficiency of HCCI was much better than for SI operation. The gross indicated efficiency showed values at 50% for the richer cases. This means that the fuel consumption at part load would be reduced to the half compared to SI operation. Very little NO{sub x} was generated with HCCI, only a few ppm. With isooctane, it ranged from 4 to below 1 ppm and with ethanol even lower values. However, HCCI generated more HC and CO. Operation was noisier with HCCI than with SI. Stable and efficient operation with HCCI could be obtained with {lambda} = 3.5 to 9 using isooctane, 3.5 to 6.5 using ethanol, and 2.5 to 3.5 using natural gas. Cycle to cycle variation of combustion was very low. Isooctane could be operated unthrottled without preheating. The selection of the high compression ratio, 21:1, was dependent on the high octane number for natural gas. The attainable IMEP was 5 bar. The limit to make higher IMEP was the rate of combustion. At IMEP 5 bar the main combustion, 10-90% burn duration, took place in less than 2 crank angle degrees (CAD). This is extremely fast and gives very high rate of pressure rise, which leads to noisy operation and high loads on the engine. The lean limit was given by unstable combustion with cycle to cycle variation of combustion, and with high emissions of unburned hydrocarbons and carbon monoxide Examination paper. 15 refs, 38 figs, 1 tab

  12. Status of the National Ignition Facility Integrated Computer Control System (ICCS) on the path to ignition

    Energy Technology Data Exchange (ETDEWEB)

    Lagin, L.J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550 (United States)], E-mail: lagin1@llnl.gov; Bettenhausen, R.C.; Bowers, G.A.; Carey, R.W.; Edwards, O.D.; Estes, C.M.; Demaret, R.D.; Ferguson, S.W.; Fisher, J.M.; Ho, J.C.; Ludwigsen, A.P.; Mathisen, D.G.; Marshall, C.D.; Matone, J.T.; McGuigan, D.L.; Sanchez, R.J.; Stout, E.A.; Tekle, E.A.; Townsend, S.L.; Van Arsdall, P.J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550 (United States)] (and others)

    2008-04-15

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility under construction that will contain a 192-beam, 1.8-MJ, 500-TW, ultraviolet laser system together with a 10-m diameter target chamber with room for multiple experimental diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. NIF's laser beams are designed to compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. NIF is comprised of 24 independent bundles of eight beams each using laser hardware that is modularized into more than 6000 line replaceable units such as optical assemblies, laser amplifiers, and multi-function sensor packages containing 60,000 control and diagnostic points. NIF is operated by the large-scale Integrated Computer Control System (ICCS) in an architecture partitioned by bundle and distributed among over 800 front-end processors and 50 supervisory servers. NIF's automated control subsystems are built from a common object-oriented software framework based on CORBA distribution that deploys the software across the computer network and achieves interoperation between different languages and target architectures. A shot automation framework has been deployed during the past year to orchestrate and automate shots performed at the NIF using the ICCS. In December 2006, a full cluster of 48 beams of NIF was fired simultaneously, demonstrating that the independent bundle control system will scale to full scale of 192 beams. At present, 72 beams have been commissioned and have demonstrated 1.4-MJ capability of infrared light. During the next 2 years, the control system will be expanded in preparation for project completion in 2009 to include automation of target area systems including

  13. Imploding ignition waves: I. one dimensional analysis

    CERN Document Server

    Kushnir, Doron; 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). We suggest that the deflagration to detonation transition (DDT) observed in these systems may be due to converging shocks produced by the turbulent deflagration flow, which reaches sub (but near) sonic velocities on scales >>R_c. Our suggested mechanism differs from that proposed by Zel'dovich et al. (1970), in which a fine tuned spatial gradient in the chemical induction time is required to be maintained within the turbulent deflagration flow. Our analysis may be readily extended to more complicated equations of state and...

  14. Large optics for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Baisden, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-12

    The National Ignition Facility (NIF) laser with its 192 independent laser beams is not only the world’s largest laser, it is also the largest optical system ever built. With its 192 independent laser beams, the NIF requires a total of 7648 large-aperture (meter-sized) optics. One of the many challenges in designing and building NIF has been to carry out the research and development on optical materials, optics design, and optics manufacturing and metrology technologies needed to achieve NIF’s high output energies and precision beam quality. This paper describes the multiyear, multi-supplier, development effort that was undertaken to develop the advanced optical materials, coatings, fabrication technologies, and associated process improvements necessary to manufacture the wide range of NIF optics. The optics include neodymium-doped phosphate glass laser amplifiers; fused silica lenses, windows, and phase plates; mirrors and polarizers with multi-layer, high-reflectivity dielectric coatings deposited on BK7 substrates; and potassium di-hydrogen phosphate crystal optics for fast optical switches, frequency conversion, and polarization rotation. Also included is a discussion of optical specifications and custom metrology and quality-assurance tools designed, built, and fielded at supplier sites to verify compliance with the stringent NIF specifications. In addition, a brief description of the ongoing program to improve the operational lifetime (i.e., damage resistance) of optics exposed to high fluence in the 351-nm (3ω) is provided.

  15. National Ignition Facility Project Site Safety Program

    Energy Technology Data Exchange (ETDEWEB)

    Dun, C

    2003-09-30

    This Safety Program for the National Ignition Facility (NIF) presents safety protocols and requirements that management and workers shall follow to assure a safe and healthful work environment during activities performed on the NIF Project site. The NIF Project Site Safety Program (NPSSP) requires that activities at the NIF Project site be performed in accordance with the ''LLNL ES&H Manual'' and the augmented set of controls and processes described in this NIF Project Site Safety Program. Specifically, this document: (1) Defines the fundamental NIF site safety philosophy. (2) Defines the areas covered by this safety program (see Appendix B). (3) Identifies management roles and responsibilities. (4) Defines core safety management processes. (5) Identifies NIF site-specific safety requirements. This NPSSP sets forth the responsibilities, requirements, rules, policies, and regulations for workers involved in work activities performed on the NIF Project site. Workers are required to implement measures to create a universal awareness that promotes safe practice at the work site and will achieve NIF management objectives in preventing accidents and illnesses. ES&H requirements are consistent with the ''LLNL ES&H Manual''. This NPSSP and implementing procedures (e.g., Management Walkabout, special work procedures, etc.,) are a comprehensive safety program that applies to NIF workers on the NIF Project site. The NIF Project site includes the B581/B681 site and support areas shown in Appendix B.

  16. National Ignition Facility Comes to Life

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E

    2003-09-01

    First conceived of nearly 15 years ago, the National Ignition Facility (NIF) is up and running and successful beyond almost everyone's expectations. During commissioning of the first four laser beams, the laser system met design specifications for everything from beam quality to energy output. NIF will eventually have 192 laser beams. Yet with just 2% of its final beam configuration complete, NIF has already produced the highest energy laser shots in the world. In July, laser shots in the infrared wavelength using four beams produced a total of 26.5 kilojoules of energy per beam, not only meeting NIF's design energy requirement of 20 kilojoules per beam but also exceeding the energy of any other infrared laser beamline. In another campaign, NIF produced over 11.4 kilojoules of energy when the infrared light was converted to green light. An earlier performance campaign of laser light that had been frequency converted from infrared to ultraviolet really proved NIF's mettle. Over 10.4 kilojoules of ultraviolet energy were produced in about 4 billionths of a second. If all 192 beamlines were to operate at these levels, over 2 megajoules of energy would result. That much energy for the pulse duration of several nanoseconds is about 500 trillion watts of power, more than 500 times the US peak generating power.

  17. Liquid Cryogenic Target Development for Fast Ignition*

    Science.gov (United States)

    Hanson, D. L.; Russell, C.; Vesey, R. A.; Schroen, D. G.; Taylor, J. L.; Back, C. A.; Steinman, D.; Nikroo, A.; Kaae, J. L.; Giraldez, E.; Johnston, R. R.; Youngman, K.

    2007-11-01

    As an alternative to foam-stabilized cryogenic solid D-T fuel layers for indirect-drive fast ignitor targets, which will tend to β-layer to a nonuniform distribution in a reentrant cone geometry [1], we are investigating hemispherical cryogenic fast ignition capsules with a liquid fuel layer confined between a thick outer ablator shell and a thin inner shell [2]. The shape and surface quality of the fuel layer is determined entirely by the characteristics of the bounding shells. In the present design, structural support for the thin (4.5 um) hemispherical GDP inner shell is provided by a mounting ring. Fabrication of stronger thin Be hemi-shells is also being investigated. Technology issues for liquid cryogenic fuel capsule development and progress toward demonstration of a working target will be presented. [1] J.K. Hoffer et al., Fusion Sci. Technol. 50, 15 (2006). [2] D.L. Hanson et al., Fusion Sci. Technol. 49, 500 (2006). *Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  18. Overview of the National Ignition Facility.

    Science.gov (United States)

    Brereton, Sandra

    2013-06-01

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the world's largest and most energetic laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. The NIF is a 192-beam, Nd-glass laser facility that is capable of producing 1.8 MJ, 500 TW of ultraviolet light, and over 50 times more energetic than other existing ICF facilities. The NIF construction began in 1997, and the facility, which was completed in 2009, is now fully operational. The facility is capable of firing up to 192 laser beams onto a target placed at the center of a 10-m-diameter spherical target chamber. Experiments involving the use of tritium have been underway for some time. These experiments present radiological issues: prompt neutron/gamma radiation, neutron activation, fission product generation, and decay radiation. This paper provides an introduction to the NIF facility and its operation, describes plans for the experimental program, and discusses radiological issues associated with the NIF's operations.

  19. Effect of long-term treatment with pramipexole or levodopa on presynaptic markers assessed by longitudinal [123I]FP-CIT SPECT and histochemistry.

    Science.gov (United States)

    Depboylu, Candan; Maurer, Lukas; Matusch, Andreas; Hermanns, Guido; Windolph, Andrea; Béhé, Martin; Oertel, Wolfgang H; Höglinger, Günter U

    2013-10-01

    A previous clinical trial studied the effect of long-term treatment with levodopa (LD) or the dopamine agonist pramipexole (PPX) on disease progression in Parkinson disease using SPECT with the dopamine transporter (DAT)-radioligand [(123)I]β-CIT as surrogate marker. [(123)I]β-CIT binding declined to significantly lower levels in patients receiving LD compared to PPX. However, the interpretation of this difference as LD-induced neurotoxicity, PPX-induced neuroprotection/-regeneration, or only drug-induced regulatory changes of DAT-availability remained controversial. To address this question experimentally, we induced a subtotal lesion of the substantia nigra in mice by bilateral injection of the neurotoxin 6-hydroxydopamine. After 4 weeks, mice were treated for 20 weeks orally with LD (100mg/kg/day) or PPX (3mg/kg/day), or water (vehicle) only. The integrity of nigrostriatal projections was assessed by repeated [(123)I]FP-CIT SPECT in vivo and by immunostaining for DAT and the dopamine-synthesizing enzyme tyrosine hydroxylase (TH) after sacrifice. In sham-lesioned mice, we found that both LD and PPX treatment significantly decreased the striatal FP-CIT binding (LD: -21%; PPX: -14%) and TH-immunoreactivity (LD: -42%; PPX: -45%), but increased DAT-immunoreactivity (LD: +42%; PPX: +33%) compared to controls without dopaminergic treatment. In 6-hydroxydopamine-lesioned mice, however, neither LD nor PPX significantly influenced the stably reduced FP-CIT SPECT signal (LD: -66%; PPX: -66%; controls -66%), TH-immunoreactivity (LD: -70%; PPX: -72%; controls: -77%) and DAT-immunoreactivity (LD: -70%; PPX: -75%; controls: -75%) in the striatum or the number of TH-positive cells in the substantia nigra (LD: -88%; PPX: -88%; controls: -86%), compared to lesioned mice without dopaminergic treatment. In conclusion, chronic dopaminergic stimulation with LD or PPX induced similar adaptive presynaptic changes in healthy mice, but no discernible changes in severely lesioned mice

  20. Clinical correlation of the binding potential with {sup 123}I-FP-CIT in de novo idiopathic Parkinson's disease patients

    Energy Technology Data Exchange (ETDEWEB)

    Berti, Valentina; Pupi, Alberto; Vanzi, Eleonora; Cristofaro, Maria Teresa de; Pellicano, Giannantonio; Mungai, Francesco [University of Florence, Clinical Pathophysiology, Florence (Italy); Ramat, Silvia; Marini, Paolo; Sorbi, Sandro [University of Florence, Neurological and Psychiatric Sciences, Florence (Italy)

    2008-12-15

    The aim of this study was to evaluate the accuracy of different single-photon emission computed tomography (SPECT) reconstruction techniques in measuring striatal N-{omega}-fluoropropyl-2{beta}-carbomethoxy-3{beta}-4-[{sup 123}I]iodophenyl-nortropane ({sup 123}I-FP-CIT) binding in de novo Parkinson's disease (PD) patients, in order to find a correlation with clinical scales of disease severity in the initial phases of disease. Thirty-six de novo PD patients underwent {sup 123}I-FP-CIT SPECT and MRI scan. SPECT data were reconstructed with filtered back projection (FBP), with an iterative algorithm (ordered subset expected maximization, OSEM) and with a method previously developed in our institution, called least-squares (LS) method. The ratio of specific to non-specific striatal {sup 123}I-FP-CIT binding (binding potential, BP) was used as the outcome measure with all the reconstruction methods (BP{sub FBP}, BP{sub OSEM}, BP{sub LS}). The range of values of striatal BP{sub LS} was significantly greater than BP{sub FBP} and BP{sub OSEM}. For all striatal regions, estimates of BP{sub FBP} correlated well with BP{sub OSEM} (r=0.84) and with BP{sub LS} (r=0.64); BP{sub OSEM} correlated significantly with BP{sub LS} (r=0.76). A good correlation was found between putaminal BP{sub LS} and Hoen and Yahr, Unified PD Rating Scale (UPDRS) and lateralized UPDRS motor scores (r=-0.46, r=-0.42, r=-0.39, respectively). Neither putaminal BP{sub FBP} nor putaminal BP{sub OSEM} correlated with any of these motor scores. In de novo PD patients, {sup 123}I-FP-CIT BP values derived from FBP and OSEM reconstruction techniques do not permit to differentiate PD severity. The LS method instead finds a correlation between striatal BP and disease severity scores. The results of this study support the use of {sup 123}I-FP-CIT BP values estimated with the LS method as a biomarker of PD severity. (orig.)

  1. Diagnostic accuracy of Parkinson disease by support vector machine (SVM) analysis of 123I-FP-CIT brain SPECT data: implications of putaminal findings and age.

    Science.gov (United States)

    Palumbo, Barbara; Fravolini, Mario Luca; Buresta, Tommaso; Pompili, Filippo; Forini, Nevio; Nigro, Pasquale; Calabresi, Paolo; Tambasco, Nicola

    2014-12-01

    Brain single-photon-emission-computerized tomography (SPECT) with I-ioflupane (I-FP-CIT) is useful to diagnose Parkinson disease (PD). To investigate the diagnostic performance of I-FP-CIT brain SPECT with semiquantitative analysis by Basal Ganglia V2 software (BasGan), we evaluated semiquantitative data of patients with suspect of PD by a support vector machine classifier (SVM), a powerful supervised classification algorithm.I-FP-CIT SPECT with BasGan analysis was performed in 90 patients with suspect of PD showing mild symptoms (bradykinesia-rigidity and mild tremor). PD was confirmed in 56 patients, 34 resulted non-PD (essential tremor and drug-induced Parkinsonism). A clinical follow-up of at least 6 months confirmed diagnosis. To investigate BasGan diagnostic performance we trained SVM classification models featuring different descriptors using both a "leave-one-out" and a "five-fold" method. In the first study we used as class descriptors the semiquantitative radiopharmaceutical uptake values in the left (L) and right (R) putamen (P) and in the L and R caudate nucleus (C) for a total of 4 descriptors (CL, CR, PL, PR). In the second study each patient was described only by CL and CR, while in the third by PL and PR descriptors. Age was added as a further descriptor to evaluate its influence in the classification performance.I-FP-CIT SPECT with BasGan analysis reached a classification performance higher than 73.9% in all the models. Considering the "Leave-one-out" method, PL and PR were better predictors (accuracy of 91% for all patients) than CL and CR descriptors; using PL, PR, CL, and CR diagnostic accuracy was similar to that of PL and PR descriptors in the different groups. Adding age as a further descriptor accuracy improved in all the models. The best results were obtained by using all the 5 descriptors both in PD and non-PD subjects (CR and CL + PR and PL + age = 96.4% and 94.1%, respectively). Similar results were observed for the "five

  2. Development and testing of an ignition physics test facility and an oxygen/methane swirl torch igniter

    Science.gov (United States)

    Flores, Jesus Roberto

    There are many advantages to LOX/methane propulsion, such as in-situ resource utilization from Mars and the Moon, and simplicity of ground operations due to its non-toxic nature. There exists a lack of fundamental understanding of the ignition physics, and flame characteristics of these propellants when related to rocket propulsion, which has created undesirably long design cycles and flight hardware that is not optimized. Motivated by these issues, a study of the ignition physics of a shear coaxial injector is proposed, in which the flow field dynamics and ignition transients will be observed through a visually accessible combustion chamber. The main goal of this work is to study the effects of geometric differences of the injector, such as recess in the liquid oxygen post and thickness of the LOX post, on the jet breakup downstream of the injector, and the flame anchoring mechanism and location. A facility was developed to support this endeavor in a safe and efficient way, including a cryogenic delivery system, a Multipurpose Optically Accessible Combustor (MOAC) with torch igniter, and a bunker with a Data Acquisition and Remote Controls system (DARCS). A swirl coflow premixed torch igniter was designed, manufactured and developed with the intent of using it as the MOAC's main ignition source. It was designed to use oxygen and methane as the propellants in an incremental step towards the goal of a LOX/methane rocket engine. Extensive testing was done on the igniter in the development phase to prove that it will reliable ignite and sustain combustion under a variety of propellant inlet conditions of which include: warm gas, cold gas, and liquid cryogenic conditions. The testing phase also provided data for component reliability and proof of concept for the testing facilities designed, especially for the cryogenic delivery system, and methane condensing unit. Future injector testing parameters of the hardware produced is included along with recommendations to

  3. Viral RNAs are unusually compact.

    Directory of Open Access Journals (Sweden)

    Ajaykumar Gopal

    Full Text Available A majority of viruses are composed of long single-stranded genomic RNA molecules encapsulated by protein shells with diameters of just a few tens of nanometers. We examine the extent to which these viral RNAs have evolved to be physically compact molecules to facilitate encapsulation. Measurements of equal-length viral, non-viral, coding and non-coding RNAs show viral RNAs to have among the smallest sizes in solution, i.e., the highest gel-electrophoretic mobilities and the smallest hydrodynamic radii. Using graph-theoretical analyses we demonstrate that their sizes correlate with the compactness of branching patterns in predicted secondary structure ensembles. The density of branching is determined by the number and relative positions of 3-helix junctions, and is highly sensitive to the presence of rare higher-order junctions with 4 or more helices. Compact branching arises from a preponderance of base pairing between nucleotides close to each other in the primary sequence. The density of branching represents a degree of freedom optimized by viral RNA genomes in response to the evolutionary pressure to be packaged reliably. Several families of viruses are analyzed to delineate the effects of capsid geometry, size and charge stabilization on the selective pressure for RNA compactness. Compact branching has important implications for RNA folding and viral assembly.

  4. Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Anderson, K. S.; Shvydky, A.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); McCrory, R. L. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

    2014-05-15

    The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8 MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6 × 10{sup 13} and ∼0.3 g/cm{sup 2}, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.

  5. Experimental and Numerical Study of Jet Controlled Compression Ignition on Combustion Phasing Control in Diesel Premixed Compression Ignition Systems

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2014-07-01

    Full Text Available In order to directly control the premixed combustion phasing, a Jet Controlled Compression Ignition (JCCI for diesel premixed compression ignition systems is investigated. Experiments were conducted on a single cylinder natural aspirated diesel engine without EGR at 3000 rpm. Numerical models were validated by load sweep experiments at fixed spark timing. Detailed combustion characteristics were analyzed based on the BMEP of 2.18 bar. The simulation results showed that the high temperature jets of reacting active radical species issued from the ignition chamber played an important role on the onset of combustion in the JCCI system. The combustion of diesel pre-mixtures was initiated rapidly by the combustion products issued from the ignition chamber. Moreover, the flame propagation was not obvious, similar to that in Pre-mixed Charge Compression Ignition (PCCI. Consequently, spark timing sweep experiments were conducted. The results showed a good linear relationship between spark timing in the ignition chamber and CA10 and CA50, which indicated the ability for direct combustion phasing control in diesel PCCI. The NOx and soot emissions gradually changed with the decrease of spark advance angle. The maximum reduction of NOx and soot were both over 90%, and HC and CO emissions were increased.

  6. 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 operational perspective discussing the composition and impact of its participants, as well as a governance perspective discussing the constraints and opportunities of the initiative as an institutionalized arena for addressing global governance gaps. The authors contrast these three perspectives and identify...... key empirical as well as conceptual scholarly contributions. The remainder of this article contains focused summaries of the articles selected for this Special Issue. All articles are introduced and evaluated against the background of the three research perspectives....

  7. Experimental Study on Igniting Self-propagating High-temperature Synthesis by Laser

    Institute of Scientific and Technical Information of China (English)

    CHEN Senchang; SHI Yusheng; HUANG Shuhuai

    2002-01-01

    An applied range of self-propagating high-temperature synthesis (SHS) is extended under igniting by laser, but there is no study in detail on its ignition process. The ignition time of SHS by laser is studied in detail in this paper for searching igniting law. A laser beam produced by CO2 laser scans back and forth along a straight line on the surface of a sample, and an ignition time is measured under different testing conditions. The results show that the ignition time is the shortest at certain mixing time, the ignition time is longer with decreasing of the density and increasing of the sample density, and the ignition time becomes shorter when pre-heat temperature rises, but the ignition time has no relation with the area and the thickness of samples when the thickness is thicker, and it has no close relation with shield gas of N2.

  8. Professional Windows Embedded Compact 7

    CERN Document Server

    Phung, Samuel; Joubert, Thierry; Hall, Mike

    2011-01-01

    Learn to program an array of customized devices and solutions As a compact, highly efficient, scalable operating system, Windows Embedded Compact 7 (WEC7) is one of the best options for developing a new generation of network-enabled, media-rich, and service-oriented devices. This in-depth resource takes you through the benefits and capabilities of WEC7 so that you can start using this performance development platform today. Divided into several major sections, the book begins with an introduction and then moves on to coverage of OS design, application development, advanced application developm

  9. Compact monolithic capacitive discharge unit

    Science.gov (United States)

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  10. Compositional effects on the ignition of FACE gasolines

    KAUST Repository

    Sarathy, Mani

    2016-05-08

    As regulatory measures for improved fuel economy and decreased emissions are pushing gasoline engine combustion technologies towards extreme conditions (i.e., boosted and intercooled intake with exhaust gas recirculation), fuel ignition characteristics become increasingly important for enabling stable operation. This study explores the effects of chemical composition on the fundamental ignition behavior of gasoline fuels. Two well-characterized, high-octane, non-oxygenated FACE (Fuels for Advanced Combustion Engines) gasolines, FACE F and FACE G, having similar antiknock indices but different octane sensitivities and chemical compositions are studied. Ignition experiments were conducted in shock tubes and a rapid compression machine (RCM) at nominal pressures of 20 and 40. atm, equivalence ratios of 0.5 and 1.0, and temperatures ranging from 650 to 1270. K. Results at temperatures above 900. K indicate that ignition delay time is similar for these fuels. However, RCM measurements below 900. K demonstrate a stronger negative temperature coefficient behavior for FACE F gasoline having lower octane sensitivity. In addition, RCM pressure profiles under two-stage ignition conditions illustrate that the magnitude of low-temperature heat release (LTHR) increases with decreasing fuel octane sensitivity. However, intermediate-temperature heat release is shown to increase as fuel octane sensitivity increases. Various surrogate fuel mixtures were formulated to conduct chemical kinetic modeling, and complex multicomponent surrogate mixtures were shown to reproduce experimentally observed trends better than simpler two- and three-component mixtures composed of n-heptane, iso-octane, and toluene. Measurements in a Cooperative Fuels Research (CFR) engine demonstrated that the multicomponent surrogates accurately captured the antiknock quality of the FACE gasolines. Simulations were performed using multicomponent surrogates for FACE F and G to reveal the underlying chemical

  11. Ignition during hydrogen release from high pressure into the atmosphere

    Science.gov (United States)

    Oleszczak, P.; Wolanski, P.

    2010-12-01

    The first investigations concerned with a problem of hydrogen jet ignition, during outflow from a high-pressure vessel were carried out nearly 40 years ago by Wolanski and Wojcicki. The research resulted from a dramatic accident in the Chorzow Chemical Plant Azoty, where the explosion of a synthesis gas made up of a mixture composed of three moles of hydrogen per mole of nitrogen, at 300°C and 30 MPa killed four people. Initial investigation had excluded potential external ignition sources and the main aim of the research was to determine the cause of ignition. Hydrogen is currently considered as a potential fuel for various vehicles such as cars, trucks, buses, etc. Crucial safety issues are of potential concern, associated with the storage of hydrogen at a very high pressure. Indeed, the evidence obtained nearly 40 years ago shows that sudden rupture of a high-pressure hydrogen storage tank or other component can result in ignition and potentially explosion. The aim of the present research is identification of the conditions under which hydrogen ignition occurs as a result of compression and heating of the air by the shock wave generated by discharge of high-pressure hydrogen. Experiments have been conducted using a facility constructed in the Combustion Laboratory of the Institute of Heat Engineering, Warsaw University of Technology. Tests under various configurations have been performed to determine critical conditions for occurrence of high-pressure hydrogen ignition. The results show that a critical pressure exists, leading to ignition, which depends mainly on the geometric configuration of the outflow system, such as tube diameter, and on the presence of obstacles.

  12. Intermediate species measurement during iso-butanol auto-ignition

    KAUST Repository

    Ji, Weiqi

    2015-10-01

    © 2015 The Combustion Institute.Published by Elsevier Inc. All rights reserved. This work presents the time histories of intermediate species during the auto-ignition of iso-butanol at high pressure and intermediate temperature conditions obtained using a rapid compression machine and recently developed fast sampling system. Iso-butanol ignition delays were acquired for iso-butanol/O2 mixture with an inert/O2 ratio of 7.26, equivalence ratio of 0.4, in the temperature range of 840-950 K and at pressure of 25 bar. Fast sampling and gas chromatography were used to acquire and quantify the intermediate species during the ignition delay of the same mixture at P = 25.3 bar and T = 905 K. The ignition delay times and quantitative measurements of the mole fraction time histories of methane, ethene, propene, iso-butene, iso-butyraldehyde, iso-butanol, and carbon monoxide were compared with predictions from the detailed mechanisms developed by Sarathy et al., Merchant et al., and Cai et al. It is shown that while the Sarathy mechanism well predicts the overall ignition delay time, it overpredicts ethene by a factor of 6-10, underpredicts iso-butene by a factor of 2, and overpredicts iso-butyraldehyde by a factor of 2. Reaction path and sensitivity analyses were carried out to identify the reactions responsible for the observed inadequacy. The rates of iso-butanol hydrogen atom abstraction by OH radical and the beta-scission reactions of hydroxybutyl radicals were updated based on recently published quantum calculation results. Significant improvements were achieved in predicting ignition delay at high pressures (25 and 30 bar) and the species concentrations of ethene and iso-butene. However, the updated mechanism still overpredicts iso-butyraldehyde concentrations. Also, the updated mechanism degrades the prediction in ignition delay at lower pressure (15 bar) compared to the original mechanism developed by Sarathy et al.

  13. Physics Experiments Planned for the National Ignition Facility

    Science.gov (United States)

    Verdon, Charles P.

    1998-11-01

    This talk will review the current status and plans for high energy density physics experiments to be conducted on the National Ignition Facility (NIF). The NIF a multi-laboratory effort, presently under construction at the Lawrence Livermore National Laboratory, is a 192 beam solid state glass laser system designed to deliver 1.8MJ (at 351nm) in temporal shaped pulses. This review will begin by introducing the NIF in the context of its role in the overall United States Stockpile Stewardship Program. The major focus of this talk will be to describe the physics experiments planned for the NIF. By way of introduction to the experiments a short review of the NIF facility design and projected capabilities will be presented. In addition the current plans and time line for the activation of the laser and experimental facilities will also be reviewed. The majority of this talk will focus on describing the national inertial confinement fusion integrated theory and experimental target ignition plan. This national plan details the theory and experimental program required for achieving ignition and modest thermonuclear gain on the NIF. This section of the presentation will include a status of the current physics basis, ignition target designs, and target fabrication issues associated with the indirect-drive and direct-drive approaches to ignition. The NIF design provides the capabilities to support experiments for both approaches to ignition. Other uses for the NIF, including non ignition physics relevant to the national security mission, studies relevant to Inertial Fusion Energy, and basic science applications, will also be described. The NIF offers the potential to generate new basic scientific understanding about matter under extreme conditions by making available a unique facility for research into: astrophysics and space physics, hydrodynamics, condensed matter physics, material properties, plasma physics and radiation sources, and radiative properties. Examples of

  14. Correlation between neuromelanin-sensitive MR imaging and {sup 123}I-FP-CIT SPECT in patients with parkinsonism

    Energy Technology Data Exchange (ETDEWEB)

    Kuya, Keita; Shinohara, Yuki; Miyoshi, Fuminori; Fujii, Shinya; Tanabe, Yoshio; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological Therapeutic Science, Faculty of Medicine, Yonago (Japan)

    2016-04-15

    Neuromelanin-sensitive MR imaging (MRI) can visualize neuromelanin-containing neurons in the substantia nigra pars compacta (SNc), and its utility has been reported in the evaluation of parkinsonism. Conversely, dopamine transporter imaging by {sup 123}I-N-v-fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl)nortropane (FP-CIT) SPECT (DaTSCAN) is now an established method for evaluating parkinsonism, detecting presynaptic dopamine neuronal dysfunction. Both methods can assist differentiating neurodegenerative and other forms of parkinsonism. However, to our knowledge, there have been no studies concerning a correlation between the two methods. The aim of this study was to assess the utility of neuromelanin-sensitive MRI for diagnosing parkinsonism by examining a correlation with DaTSCAN. Twenty-three patients with parkinsonism who underwent both neuromelanin-sensitive MRI and DaTSCAN were included. We measured the neuromelanin-positive SNc region volume by manually contouring the high signal intensity region of the SNc on neuromelanin-sensitive MRI and measured the specific binding ratio (SBR) on DaTSCAN. The asymmetry index of neuromelanin-positive SNc volume and the asymmetry index of SBR were also calculated. The volume of the neuromelanin-positive SNc region showed significant correlation with specific binding ratio (SBR) (right P <.001, ρ = 0.78, left P <.001, ρ = 0.86). The asymmetry index of neuromelanin-positive SNc volume also showed significant correlations with the asymmetry index of SBR (P <.001, ρ = 0.73). Decrease of the high signal intensity region of the SNc on neuromelanin-sensitive MRI would indicate damage to the nigrostriatal dopaminergic function as well as loss of dopaminergic neurons. We conclude that neuromelanin-sensitive MRI is a useful diagnostic biomarker for parkinsonism. (orig.)

  15. 123I-FP-CIT SPECT imaging in early diagnosis of dementia in patients with and without a vascular component

    Directory of Open Access Journals (Sweden)

    Marina eGarriga

    2015-07-01

    Full Text Available Alzheimer’s disease (AD and vascular dementia (VaD are the most common cause of dementia. Cerebral ischemia is a major risk factor for development of dementia. 123I-FP-CIT SPECT (DaTScan is a complementary tool in the differential diagnoses of patients with incomplete or uncertain Parkinsonism. Additional application of DaTScan enables the categorization of Parkinsonian disease with dementia (PDD, and its differentiation from pure AD, and may further contribute to change the therapeutic decision. The aim of this study was to analyse the vascular contribution towards dementia and mild cognitive impairment (MCI. We evaluated the utility of DaTScan for the early diagnosis of dementia in patients with and without a clinical vascular component, and the association between neuropsychological function, vascular component and dopaminergic function on DaTScan. 105 patients with MCI or the initial phases of dementia were studied prospectively. We developed an initial assessment using neurologic examination, blood tests, cognitive function tests, structural neuroimaging and DaTScan. The vascular component was later quantified in two ways: clinically, according to the Framingham Risk Score and by structural neuroimaging using Wahlund Scale Total Score (WSTS. Early diagnosis of dementia was associated with an abnormal DaTScan. A significant association was found between a high WSTS and an abnormal DaTScan (p<0.01. Mixed AD was the group with the highest vascular component, followed by the VaD group, while MCI and pure AD showed similar WSTS. No significant associations were found between neuropsychological impairment and DaTScan independently of associated vascular component. DaTScan seems to be a good tool to discriminate, in a first clinical assessment, patients with MCI from those with established dementia. There was bigger general vascular affectation observable in MRI or CT in patients with abnormal dopaminergic uptake seen on DaTScan.

  16. Possible version of the compression degradation of the thermonuclear indirect-irradiation targets at the national ignition facility and a reason for the failure of ignition

    Science.gov (United States)

    Rozanov, V. B.; Vergunova, G. A.

    2017-01-01

    The main parameters of compression of a target and tendencies at change in the irradiation conditions are determined by analyzing the published results of experiments at the megajoule National Ignition Facility (NIF) on the compression of capsules in indirect-irradiation targets by means of the one-dimensional RADIAN program in the spherical geometry. A possible version of the "failure of ignition" of an indirect-irradiation target under the NIF conditions is attributed to radiation transfer. The application of onedimensional model to analyze the National Ignition Campaign (NIC) experiments allows identifying conditions corresponding to the future ignition regime and distinguishing them from conditions under which ignition does not occur.

  17. A Theoretical Model for Laser Ignition of Condensed Selfreaction Materials%凝聚态自反应材料激光点火理论模型

    Institute of Scientific and Technical Information of China (English)

    沈平; 连建设; 胡建东; 郭作兴; 孙炳云

    2001-01-01

    基于热理论建立了凝聚态自反应材料的一维激光点火理论模型,并对其作了解析以揭示点火延迟时间与激光处理参数和材料特征之间的关系。尝试进行了激光点燃Ni-33.3at%Al粉末压坯的实验,并将实验值与计算值做了对比以验证模型的合理性。结果表明计算值与实验值吻合较好。因此,激光辐射点火从根本上应归结于热的作用。%A theoretical model for laser -induced ignition of condensed self -reaction materials was set up based on thermal theory,and an analytical solution wassought to reveal the relationship of ignition delay time with laser processing parameters as well as material characteristics. An experiment of laser ignition of Ni - 33.3 at% Al powder compacts was also attempted and the comparison between experimental and computational data of ignition delay time was made to verify the validity of the model. The results show that the calculated values agree well with that of the experiment. As a consequence, the mechanism of ignition by laser beams irradiation can be attributed to thermal in origin.

  18. Fundamental Interactions in Gasoline Compression Ignition Engines with Fuel Stratification

    Science.gov (United States)

    Wolk, Benjamin Matthew

    Transportation accounted for 28% of the total U.S. energy demand in 2011, with 93% of U.S. transportation energy coming from petroleum. The large impact of the transportation sector on global climate change necessitates more-efficient, cleaner-burning internal combustion engine operating strategies. One such strategy that has received substantial research attention in the last decade is Homogeneous Charge Compression Ignition (HCCI). Although the efficiency and emissions benefits of HCCI are well established, practical limits on the operating range of HCCI engines have inhibited their application in consumer vehicles. One such limit is at high load, where the pressure rise rate in the combustion chamber becomes excessively large. Fuel stratification is a potential strategy for reducing the maximum pressure rise rate in HCCI engines. The aim is to introduce reactivity gradients through fuel stratification to promote sequential auto-ignition rather than a bulk-ignition, as in the homogeneous case. A gasoline-fueled compression ignition engine with fuel stratification is termed a Gasoline Compression Ignition (GCI) engine. Although a reasonable amount of experimental research has been performed for fuel stratification in GCI engines, a clear understanding of how the fundamental in-cylinder processes of fuel spray evaporation, mixing, and heat release contribute to the observed phenomena is lacking. Of particular interest is gasoline's pressure sensitive low-temperature chemistry and how it impacts the sequential auto-ignition of the stratified charge. In order to computationally study GCI with fuel stratification using three-dimensional computational fluid dynamics (CFD) and chemical kinetics, two reduced mechanisms have been developed. The reduced mechanisms were developed from a large, detailed mechanism with about 1400 species for a 4-component gasoline surrogate. The two versions of the reduced mechanism developed in this work are: (1) a 96-species version and (2

  19. DNA compaction by nonbinding macromolecules

    NARCIS (Netherlands)

    Vries, de R.J.

    2012-01-01

    Compaction of DNA by nonbinding macromolecules such as uncharged flexible polymer chains and negatively charged globular proteins is thought to have various applications in biophysics, for example in the formation of a nucleoid structure in bacteria. A simple experimental model that has been very we

  20. Fuzzy Soft Compact Topological Spaces

    Directory of Open Access Journals (Sweden)

    Seema Mishra

    2016-01-01

    Full Text Available In this paper, we have studied compactness in fuzzy soft topological spaces which is a generalization of the corresponding concept by R. Lowen in the case of fuzzy topological spaces. Several basic desirable results have been established. In particular, we have proved the counterparts of Alexander’s subbase lemma and Tychonoff theorem for fuzzy soft topological spaces.

  1. JACKSON'S THEOREM FOR COMPACT GROUPS

    Institute of Scientific and Technical Information of China (English)

    H. Vaezi; S. F. Rzaev

    2002-01-01

    In this article we consider the generalized shift operator defined by(Sh.f)(g) = ∫Gf (tut-1g)dton compact group G and by help of this operator we define "Spherical" modulus of continuity. So we proveStechkin and Jackson type theorems.

  2. The Compact Project: Final Report.

    Science.gov (United States)

    National Alliance of Business, Inc., Washington, DC.

    The National Alliance of Business (NAB) surveyed the 12 sites that participated in the Compact Project to develop and implement programs of business-education collaboration. NAB studied start-up activities, key players, conditions for collaboration, accomplishments, challenges, and future plans. Program outcomes indicated that building successful…

  3. Compact Photon Source Conceptual Design

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarenko, Pavel V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wojtsekhowski, Bogdan B. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-04-01

    We describe options for the production of an intense photon beam at the CEBAF Hall D Tagger facility, needed for creating a high-quality secondary K 0 L delivered to the Hall D detector. The conceptual design for the Compact Photon Source apparatus is presented.

  4. Power deposition of deuteron beam in fast ignition

    Science.gov (United States)

    Azadifar, R.; Mahdavi, M.

    2017-02-01

    In ion fast ignition (FI) inertial confinement fusion (ICF), a laser accelerated ion beam called igniter provides energy required for ignition of a fuel pellet. The laser accelerated deuteron beam is considered as igniter. The deuteron beam with Maxwellian energy distribution produced at the distance d = 500 μm, from fuel surface, travels during time t = 20 ps and arrives with power P1D(t,TD) to the fuel surface. Then, the deuteron beam deposits its energy into fuel by Coulomb and nuclear interactions with background plasma particles during time t = 10 ps, with power P2D(t,TD,Tb). Since time and power of the two stages have same order, to calculate the total power deposited by igniter beam, both stages must be considered simultaneously. In this paper, the exact power of each stage has been calculated separately, and the total power Ptotal(t,TD,Tb) has been obtained. The obtained results show that the total power deposition Ptotal(t,TD,Tb) is significantly reduced due to reducing different temperature between projectile and target particles.

  5. LES of an ignition sequence in a gas turbine engine

    Energy Technology Data Exchange (ETDEWEB)

    Boileau, M.; Staffelbach, G.; Cuenot, B. [CERFACS, Toulouse (France); Poinsot, T. [IMFT - CNRS, Toulouse (France); Berat, C. [Turbomeca (SAFRAN group), Bordes (France)

    2008-07-15

    Being able to ignite or reignite a gas turbine engine in a cold and rarefied atmosphere is a critical issue for many manufacturers. From a fundamental point of view, the ignition of the first burner and the flame propagation from one burner to another are phenomena that are usually not studied. The present work is a large eddy simulation (LES) of these phenomena. To simulate a complete ignition sequence in an annular chamber, LES has been applied to the full 360 geometry, including 18 burners. This geometry corresponds to a real gas turbine chamber. Massively parallel computing (700 processors on a Cray XT3 machine) was essential to perform such a large calculation. Results show that liquid fuel injection has a strong influence on the ignition times. Moreover, the rate of flame progress from burner to burner is much higher than the turbulent flame speed due to a major effect of thermal expansion. This flame speed is also strongly modified by the main burner aerodynamics due to the swirled injection. Finally, the variability of the combustor sectors and quadrant ignition times is highlighted. (author)

  6. A Steam-Plasma Igniter for Aluminum Powder Combustion

    Science.gov (United States)

    Sanghyup, Lee; Kwanyoung, Noh; Jihwan, Lim; Woongsup, Yoon

    2015-05-01

    High-temperature ignition is essential for the ignition and combustion of energetic metal fuels, including aluminum and magnesium particles which are protected by their high-melting-temperature oxides. A plasma torch characterized by an ultrahigh-temperature plasma plume fulfills such high-temperature ignition conditions. A new steam plasma igniter is designed and successfully validated by aluminum power ignition and combustion tests. The steam plasma rapidly stabilizes in both plasma and steam jet modes. Parametric investigation of the steam plasma jet is conducted in terms of arc strength. A high-speed camera and an oscilloscope method visualize the discharge characteristics, and optical emission spectroscopy measures the thermochemical properties of the plasma jet. The diatomic molecule OH fitting method, the Boltzmann plot method, and short exposure capturing with an intensified charge coupled device record the axial distributions of the rotational gas temperature, excitation temperature, and OH radical distribution, respectively. The excitation temperature at the nozzle tip is near 5500 K, and the gas temperature is 5400 K.

  7. Path To Ignition: US Indirect Target Physics (LIRPP Vol. 12)

    Science.gov (United States)

    Cray, M.; Campbell, E. M.

    2016-10-01

    The United States ICF Program has been pursuing an aggressive research program in preparation for an ignition demonstration on the National Ignition Facility. Los Alamos and Livermore laboratories have collaborated on resolving indirect drive target physics issues on the Nova laser at Livermore National Laboratory. This combined with detailed modeling of laser heated indirectly driven targets likely to achieve ignition, has provided the basis for planning for the NIF. A detailed understanding of target physics, laser performance, and target fabrication is required for developing robust ignition targets. We have developed large-scale computational models to simulate complex physics which occurs in an indirectly driven target. For ignition, detailed understanding of hohlraum and implosion physics is required in order to control competing processes at the few percent level. From crucial experiments performed by Los Alamos and Livermore on the Nova laser, a comprehensive indirect drive database has been assembled. Time integrated and time dependent measurements of radiation drive and symmetry coupled with a detailed set of plasma instability measurements have confirmed our ability to predict hohlraum energetics. Implosion physics campaigns are focused on underdstanding detailed capsule hydrodynamics and instability growth. Target fabrication technology is also an active area of research at Los Alamos, Livermore, and General Atomics for NIF. NIF targets require developing technology in cryogenics and manufacturing in such areas as beryllium shell manufacture. Descriptions of our NIF target designs, experimental results, and fabrication technology supporting NIF target performance predictions will be given.

  8. On sequential countably compact topological semigroups

    CERN Document Server

    Gutik, Oleg V; Repovš, Dušan

    2008-01-01

    We study topological and algebraic properties of sequential countably compact topological semigroups similar to compact topological semigroups. We prove that a sequential countably compact topological semigroup does not contain the bicyclic semigroup. Also we show that the closure of a subgroup in a sequential countably compact topological semigroup is a topological group, that the inversion in a Clifford sequential countably compact topological semigroup is continuous and we prove the analogue of the Rees-Suschkewitsch Theorem for simple regular sequential countably compact topological semigroups.

  9. Compaction and relaxation of biofilms

    KAUST Repository

    Valladares Linares, R.

    2015-06-18

    Operation of membrane systems for water treatment can be seriously hampered by biofouling. A better characterization of biofilms in membrane systems and their impact on membrane performance may help to develop effective biofouling control strategies. The objective of this study was to determine the occurrence, extent and timescale of biofilm compaction and relaxation (decompaction), caused by permeate flux variations. The impact of permeate flux changes on biofilm thickness, structure and stiffness was investigated in situ and non-destructively with optical coherence tomography using membrane fouling monitors operated at a constant crossflow velocity of 0.1 m s−1 with permeate production. The permeate flux was varied sequentially from 20 to 60 and back to 20 L m−2 h−1. The study showed that the average biofilm thickness on the membrane decreased after elevating the permeate flux from 20 to 60 L m−2 h−1 while the biofilm thickness increased again after restoring the original flux of 20 L m−2 h−1, indicating the occurrence of biofilm compaction and relaxation. Within a few seconds after the flux change, the biofilm thickness was changed and stabilized, biofilm compaction occurred faster than the relaxation after restoring the original permeate flux. The initial biofilm parameters were not fully reinstated: the biofilm thickness was reduced by 21%, biofilm stiffness had increased and the hydraulic biofilm resistance was elevated by 16%. Biofilm thickness was related to the hydraulic biofilm resistance. Membrane performance losses are related to the biofilm thickness, density and morphology, which are influenced by (variations in) hydraulic conditions. A (temporarily) permeate flux increase caused biofilm compaction, together with membrane performance losses. The impact of biofilms on membrane performance can be influenced (increased and reduced) by operational parameters. The article shows that a (temporary) pressure increase leads to more

  10. Data Analysis, Pre-Ignition Assessment, and Post-Ignition Modeling of the Large-Scale Annular Cookoff Tests

    Energy Technology Data Exchange (ETDEWEB)

    G. Terrones; F.J. Souto; R.F. Shea; M.W.Burkett; E.S. Idar

    2005-09-30

    In order to understand the implications that cookoff of plastic-bonded explosive-9501 could have on safety assessments, we analyzed the available data from the large-scale annular cookoff (LSAC) assembly series of experiments. In addition, we examined recent data regarding hypotheses about pre-ignition that may be relevant to post-ignition behavior. Based on the post-ignition data from Shot 6, which had the most complete set of data, we developed an approximate equation of state (EOS) for the gaseous products of deflagration. Implementation of this EOS into the multimaterial hydrodynamics computer program PAGOSA yielded good agreement with the inner-liner collapse sequence for Shot 6 and with other data, such as velocity interferometer system for any reflector and resistance wires. A metric to establish the degree of symmetry based on the concept of time of arrival to pin locations was used to compare numerical simulations with experimental data. Several simulations were performed to elucidate the mode of ignition in the LSAC and to determine the possible compression levels that the metal assembly could have been subjected to during post-ignition.

  11. The Effect of Spark Timing on the Spark Ignition

    Directory of Open Access Journals (Sweden)

    Rafeq A. Khalefa

    2013-04-01

    Full Text Available  In this work the effect of spark timing on the spark ignition engines is investigated by computer simulation and experimental test for speeds of (1500,2000,2500,3000 and 3500rpm at spark timing of (20o,30o,40o,50o and 60o before TDC for each speed. This is done in order to find a suitable  mathematical expression for spark ignition advancing with respect to the speed of the engine to predict the correct ignition advance  as in real engines .The results showed that the method of using a mathematical expression is more realistic and reasonable  comparing  with the results obtained by other workers. 

  12. Tokamak power reactor ignition and time dependent fractional power operation

    Energy Technology Data Exchange (ETDEWEB)

    Vold, E.L.; Mau, T.K.; Conn, R.W.

    1986-06-01

    A flexible time-dependent and zero-dimensional plasma burn code with radial profiles was developed and employed to study the fractional power operation and the thermal burn control options for an INTOR-sized tokamak reactor. The code includes alpha thermalization and a time-dependent transport loss which can be represented by any one of several currently popular scaling laws for energy confinement time. Ignition parameters were found to vary widely in density-temperature (n-T) space for the range of scaling laws examined. Critical ignition issues were found to include the extent of confinement time degradation by alpha heating, the ratio of ion to electron transport power loss, and effect of auxiliary heating on confinement. Feedback control of the auxiliary power and ion fuel sources are shown to provide thermal stability near the ignition curve.

  13. Ignition Delay Times of Kerosene(Jet-A)/Air Mixtures

    CERN Document Server

    Zhukov, V P; Starikovskii, A Yu

    2012-01-01

    Ignition of Jet-A/air mixtures was studied behind reflected shock waves. Heating of shock tube at temperature of 150 C was used to prepare a homogeneous fuel mixture. Ignition delay times were measured from OH emission at 309 nm and from absorption of He-Ne laser radiation at 3.3922 micrometers. The conditions behind shock waves were calculated by one-dimensional shock wave theory from initial conditions T1, P1, mixture composition and incident shock wave velocity. The ignition delay times were obtained at two fixed pressures 10, 20 atm for lean, stoichiometric and rich mixtures (ER=0.5, 1, 2) at an overall temperature range of 1040-1380 K.

  14. Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids

    Science.gov (United States)

    Osipov, V. V.; Muratov, C. B.; Ponizovskaya-Devine, E.; Foygel, M.; Smelyanskiy, V. N.

    2011-03-01

    The Challenger disaster and purposeful experiments with liquid hydrogen (H2) and oxygen (Ox) tank breaches demonstrated that cryogenic H2/Ox fluids always self-ignite in the process of their sudden mixing. Here, we propose a cavitation-induced self-ignition mechanism that may be realized under these conditions. In one possible scenario, self-ignition is caused by the strong shock waves generated by the collapse of pure Ox vapor bubble near the surface of the Ox liquid that may initiate detonation of the gaseous H2/Ox mixture next to the gas-liquid interface. This effect is further enhanced by H2/Ox combustion inside the collapsing bubble in the presence of admixed H2 gas.

  15. Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids

    CERN Document Server

    Osipov, V V; Ponizovskya-Devine, E; Foygel, M; Smelyanskiy, V N

    2011-01-01

    The Challenger disaster and purposeful experiments with liquid hydrogen (H2) and oxygen (Ox) tanks demonstrated that cryogenic H2/Ox fluids always self-ignite in the process of their mixing. Here we propose a cavitation-induced self-ignition mechanism that may be realized under these conditions. In one possible scenario, self-ignition is caused by the strong shock waves generated by the collapse of pure Ox vapor bubble near the surface of the Ox liquid that may initiate detonation of the gaseous H2/Ox mixture adjacent to the gas-liquid interface. This effect is further enhanced by H2/Ox combustion inside the collapsing bubble in the presence of admixed H2 gas.

  16. Features of Ignition and Stable Combustion in Supersonic Combustor

    Science.gov (United States)

    Goldfeld, M.; Starov, A.; Timofeev, K.

    2009-01-01

    Present paper describes the results of experimental investigations of the supersonic combustor with entrance Mach numbers from 2 to 4 at static pressure from 0.8 to 2.5 bars, total temperature from 2000K to 3000K. Hydrogen and kerosene were used as fuel. The conditions, under which the self-ignition and intensive combustion of the fuel realized were found. Position of ignition area in the channel was determined and features of flame propagation in the channel presented. A possibility to ensure an efficient combustion of hydrogen and kerosene at a high supersonic flow velocity at the combustor entrance without special throttling and/or pseudo-shock introduction was shown. Analysis of applicability of existing methods of criterion descriptions of conditions of self-ignition and extinction of combustion is executed for generalization of experimental results on the basis of results obtained.

  17. Compression ignition of hydrogen-containing mixtures in shock tubes

    Science.gov (United States)

    Medvedev, S. P.; Gelfand, B. E.; Khomik, S. V.; Agafonov, G. L.

    2010-12-01

    The state of the art of the problem of discrepancy between the values measured in shock tubes and calculated for the delay of ignition of hydrogen-containing systems has been analyzed. It is shown that in the low-temperature region the off-design appearance of reaction sites leads to the propagation of a flame in a mixture heated by a reflected shock wave. The parameter of the time of mixture combustion in a deflagration regime has been introduced and the use of it together with the calculated delay in self-ignition for delimitation and classification of thermal and gas-dynamic phenomena on compression ignition of hydrogen-containing mixtures in shock tubes has been suggested.

  18. Ignition characteristics of 2-methyltetrahydrofuran: An experimental and kinetic study

    KAUST Repository

    Tripathi, Rupali

    2016-10-15

    The present paper elucidates oxidation behavior of 2-methyltetrahydrofuran (2-MTHF), a novel second-generation biofuel. New experimental data sets for 2-MTHF including ignition delay time measurements in two different combustion reactors, i.e. rapid compression machine and high-pressure shock tube, are presented. Measurements for 2-MTHF/oxidizer/diluent mixtures were performed in the temperature range of . 639-1413 K, at pressures of 10, 20, and 40 bar, and at three different equivalence ratios of 0.5, 1.0, and 2.0. A detailed chemical kinetic model describing both low-and high-temperature chemistry of 2-MTHF was developed and validated against new ignition delay measurements and already existing flame species profiles and ignition delay measurements. The mechanism provides satisfactory agreement with the experimental data. For identifying key reactions at various combustion conditions and to attain a better understanding of the combustion behavior, reaction path and sensitivity analyses were performed.

  19. Shock timing on the National Ignition Facility: First experiments

    Science.gov (United States)

    Celliers, P. M.; Robey, H. F.; Boehly, T. R.; Alger, E.; Azevedo, S.; Berzins, L. V.; Bhandarkar, S. D.; Bowers, M. W.; Brereton, S. J.; Callahan, D.; Castro, C.; Chandrasekaran, H.; Choate, C.; Clark, D. S.; Coffee, K. R.; Datte, P. S.; Dewald, E. L.; DiNicola, P.; Dixit, S.; Döppner, T.; Dzenitis, E.; Edwards, M. J.; Eggert, J. H.; Fair, J.; Farley, D. R.; Frieders, G.; Gibson, C. R.; Giraldez, E.; Haan, S.; Haid, B.; Hamza, A. V.; Haynam, C.; Hicks, D. G.; Holunga, D. M.; Horner, J. B.; Jancaitis, K.; Jones, O. S.; Kalantar, D.; Kline, J. L.; Krauter, K. G.; Kroll, J. J.; LaFortune, K. N.; Le Pape, S.; Malsbury, T.; Mapoles, E. R.; Meezan, N. B.; Milovich, J. L.; Moody, J. D.; Moreno, K.; Munro, D. H.; Nikroo, A.; Olson, R. E.; Parham, T.; Pollaine, S.; Radousky, H. B.; Ross, G. F.; Sater, J.; Schneider, M. B.; Shaw, M.; Smith, R. F.; Sterne, P. A.; Thomas, C. A.; Throop, A.; Town, R. P. J.; Trummer, D.; Van Wonterghem, B. M.; Walters, C. F.; Widmann, K.; Widmayer, C.; Young, B. K.; Atherton, L. J.; Collins, G. W.; Landen, O. L.; Lindl, J. D.; MacGowan, B. J.; Meyerhofer, D. D.; Moses, E. I.

    2013-11-01

    An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a re-entrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

  20. Shock timing on the National Ignition Facility: First experiments

    Directory of Open Access Journals (Sweden)

    Celliers P.M.

    2013-11-01

    Full Text Available An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a re-entrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

  1. Propellant Flow Actuated Piezoelectric Igniter for Combustion Engines

    Science.gov (United States)

    Wollen, Mark A. (Inventor)

    2015-01-01

    A propellant flow actuated piezoelectric igniter device using one or more hammer balls retained by one or more magnets, or other retaining method, until sufficient fluid pressure is achieved to release and accelerate the hammer ball, such that it impacts a piezoelectric crystal to produce an ignition spark. Certain preferred embodiments provide a means for repetitively capturing and releasing the hammer ball after it impacts one or more piezoelectric crystals, thereby oscillating and producing multiple, repetitive ignition sparks. Furthermore, an embodiment is presented for which oscillation of the hammer ball and repetitive impact to the piezoelectric crystal is maintained without the need for a magnet or other retaining mechanism to achieve this oscillating impact process.

  2. Volume Ignition via Time-like Detonation in Pellet Fusion

    CERN Document Server

    Csernai, L P

    2015-01-01

    Relativistic fluid dynamics and the theory of relativistic detonation fronts are used to estimate the space-time dynamics of the burning of the D-T fuel in Laser driven pellet fusion experiments. The initial "High foot" heating of the fuel makes the compressed target transparent to radiation, and then a rapid ignition pulse can penetrate and heat up the whole target to supercritical temperatures in a short time, so that most of the interior of the target ignites almost simultaneously and instabilities will have no time to develop. In these relativistic, radiation dominated processes both the interior, time-like burning front and the surrounding space-like part of the front will be stable against Rayleigh-Taylor instabilities. To achieve this rapid, volume ignition the pulse heating up the target to supercritical temperature should provide the required energy in less than ~ 10 ps.

  3. Recent Advances in Cigarette Ignition Propensity Research and Development.

    Science.gov (United States)

    Alpert, Hillel R; O'Connor, Richard J; Spalletta, Ron; Connolly, Gregory N

    2010-04-01

    Major U.S. cigarette companies for decades conducted research and development regarding cigarette ignition propensity which has continued beyond fire safety standards for cigarettes that have recently been legislated. This paper describes recent scientific advances and technological development based on a comprehensive review of the physical, chemical, and engineering sciences, public health, and trade literature, U.S. and international patents, and research in the tobacco industry document libraries.Advancements since the first implementation of standards have made been in: a) understanding the key parameters involved in cigarette smoldering combustion and ignition of substrates; b) developing new cigarette and paper wrapper designs to reduce ignition propensity, including banded and non-banded cigarette paper approaches, c) assessing toxicology, and d) measuring performance. While the implications of manufacturers' non-safety related aims are of concern, this research indicates possible alternative designs should experience with fire loss and existing technologies on the market suggest need for improvement.

  4. A Study on Homogeneous Charge Compression Ignition Gasoline Engines

    Science.gov (United States)

    Kaneko, Makoto; Morikawa, Koji; Itoh, Jin; Saishu, Youhei

    A new engine concept consisting of HCCI combustion for low and midrange loads and spark ignition combustion for high loads was introduced. The timing of the intake valve closing was adjusted to alter the negative valve overlap and effective compression ratio to provide suitable HCCI conditions. The effect of mixture formation on auto-ignition was also investigated using a direct injection engine. As a result, HCCI combustion was achieved with a relatively low compression ratio when the intake air was heated by internal EGR. The resulting combustion was at a high thermal efficiency, comparable to that of modern diesel engines, and produced almost no NOx emissions or smoke. The mixture stratification increased the local A/F concentration, resulting in higher reactivity. A wide range of combustible A/F ratios was used to control the compression ignition timing. Photographs showed that the flame filled the entire chamber during combustion, reducing both emissions and fuel consumption.

  5. AN INTRODUCTION TO A HOMOGENEOUS CHARGE COMPRESSION IGNITION ENGINE

    Directory of Open Access Journals (Sweden)

    A.A. Hairuddin

    2014-12-01

    Full Text Available Homogeneous charge compression ignition (HCCI engine technology is relatively new and has not matured sufficiently to be commercialised compared with conventional engines. It can use spark ignition or compression ignition engine configurations, capitalizing on the advantages of both: high engine efficiency with low emissions levels. HCCI engines can use a wide range of fuels with low emissions levels. Due to these advantages, HCCI engines are suitable for use in a hybrid engine configuration, where they can reduce the fuel consumption even further. However, HCCI engines have some disadvantages, such as knocking and a low to medium operating load range, which need to be resolved before the engine can be commercialised. Therefore, a comprehensive study has to be performed to understand the behaviour of HCCI engines.

  6. Characterizing pyrotechnic igniter output with high-speed schlieren imaging

    Science.gov (United States)

    Skaggs, M. N.; Hargather, M. J.; Cooper, M. A.

    2017-01-01

    Small-scale pyrotechnic igniter output has been characterized using a high-speed schlieren imaging system for observing critical features of the post-combustion flow. The diagnostic, with laser illumination, was successfully applied towards the quantitative characterization of the output from Ti/KClO_4 and TiH_{1.65}/KClO_4 pyrotechnic igniters. The high-speed image sequences showed shock motion, burned gas expansion, and particle motion. A statistical-based analysis methodology for tracking the full-field shock motion enabled straightforward comparisons across the experimental parameters of pyrotechnic material and initial density. This characterization of the mechanical energy of the shock front within the post-combustion environment is a necessary addition to the large body of literature focused on pyrotechnic combustion behavior within the powder bed. Ultimately, understanding the role that the combustion behavior has on the resulting multiphase environment is required for tailored igniter development and comparative performance assessments.

  7. Ion beam requirements for fast ignition of inertial fusion targets

    CERN Document Server

    Honrubia, J J

    2015-01-01

    Ion beam requirements for fast ignition are investigated by numerical simulation taking into account new effects such as ion beam divergence not included before. We assume that ions are generated by the TNSA scheme in a curved foil placed inside a re-entrant cone and focused on the cone apex or beyond. From the focusing point to the compressed core ions propagate with a given divergence angle. Ignition energies are obtained for two compressed fuel configurations heated by proton and carbon ion beams. The dependence of the ignition energies on the beam divergence angle and on the position of the ion beam focusing point have been analysed. Comparison between TNSA and quasi-monoenergetic ions is also shown.

  8. WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, M.; Robinson, C.; Gupta, N.; Werth, D.

    2012-10-10

    This report describes the development of a software tool, entitled “WildFire Ignition Resistance Estimator Wizard” (WildFIRE Wizard, Version 2.10). This software was developed within the Wildfire Ignition Resistant Home Design (WIRHD) program, sponsored by the U. S. Department of Homeland Security, Science and Technology Directorate, Infrastructure Protection & Disaster Management Division. WildFIRE Wizard is a tool that enables homeowners to take preventive actions that will reduce their home’s vulnerability to wildfire ignition sources (i.e., embers, radiant heat, and direct flame impingement) well in advance of a wildfire event. This report describes the development of the software, its operation, its technical basis and calculations, and steps taken to verify its performance.

  9. The effect of shock dynamics on compressibility of ignition-scale National Ignition Facility implosions

    Energy Technology Data Exchange (ETDEWEB)

    Zylstra, A. B., E-mail: zylstra@mit.edu; Frenje, J. A.; Séguin, F. H.; Rosenberg, M. J.; Rinderknecht, H. G.; Gatu Johnson, M.; Li, C. K.; Manuel, M. J.-E.; Petrasso, R. D.; Sinenian, N.; Sio, H. W. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Hicks, D. G.; Dewald, E. L.; Robey, H. F.; Rygg, J. R.; Meezan, N. B.; Friedrich, S.; Bionta, R.; Atherton, J.; Barrios, M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2014-11-15

    The effects of shock dynamics on compressibility of indirect-drive ignition-scale surrogate implosions, CH shells filled with D{sup 3}He gas, have been studied using charged-particle spectroscopy. Spectral measurements of D{sup 3}He protons produced at the shock-bang time probe the shock dynamics and in-flight characteristics of an implosion. The proton shock yield is found to vary by over an order of magnitude. A simple model relates the observed yield to incipient hot-spot adiabat, suggesting that implosions with rapid radiation-power increase during the main drive pulse may have a 2× higher hot-spot adiabat, potentially reducing compressibility. A self-consistent 1-D implosion model was used to infer the areal density (ρR) and the shell center-of-mass radius (R{sub cm}) from the downshift of the shock-produced D{sup 3}He protons. The observed ρR at shock-bang time is substantially higher for implosions, where the laser drive is on until near the compression bang time (“short-coast”), while longer-coasting implosions have lower ρR. This corresponds to a much larger temporal difference between the shock- and compression-bang time in the long-coast implosions (∼800 ps) than in the short-coast (∼400 ps); this will be verified with a future direct bang-time diagnostic. This model-inferred differential bang time contradicts radiation-hydrodynamic simulations, which predict constant 700–800 ps differential independent of coasting time; this result is potentially explained by uncertainties in modeling late-time ablation drive on the capsule. In an ignition experiment, an earlier shock-bang time resulting in an earlier onset of shell deceleration, potentially reducing compression and, thus, fuel ρR.

  10. High Impact Technology Compact Combustion (HITCC) Compact Core Technologies

    Science.gov (United States)

    2016-01-01

    correlation as the chemical “timescale.” The resulting correlation equation is Eq 22. Including laminar flame speed improved the R-squared value from...including: 1) ultra-compact combustors, 2) inter-turbine burner concepts, 3) bluff-body stabilized turbulent flames, 4) well-stirred reactors for... chemical kinetics, and 5) detonation-stabilized turbulent flames. Lean blowout data was collected on propane and jet fuel bluff-body stabilized flames

  11. Shot Automation for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Lagin, L J; Bettenhausen, R C; Beeler, R G; Bowers, G A; Carey, R; Casavant, D D; Cline, B D; Demaret, R D; Domyancic, D M; Elko, S D; Fisher, J M; Hermann, M R; Krammen, J E; Kohut, T R; Marshall, C D; Mathisen, D G; Ludwigsen, A P; Patterson, Jr., R W; Sanchez, R J; Stout, E A; Van Arsdall, P J; Van Wonterghem, B M

    2005-09-21

    A shot automation framework has been developed and deployed during the past year to automate shots performed on the National Ignition Facility (NIF) using the Integrated Computer Control System This framework automates a 4-8 hour shot sequence, that includes inputting shot goals from a physics model, set up of the laser and diagnostics, automatic alignment of laser beams and verification of status. This sequence consists of set of preparatory verification shots, leading to amplified system shots using a 4-minute countdown, triggering during the last 2 seconds using a high-precision timing system, followed by post-shot analysis and archiving. The framework provides for a flexible, model-based execution driven of scriptable automation called macro steps. The framework is driven by high-level shot director software that provides a restricted set of shot life cycle state transitions to 25 collaboration supervisors that automate 8-laser beams (bundles) and a common set of shared resources. Each collaboration supervisor commands approximately 10 subsystem shot supervisors that perform automated control and status verification. Collaboration supervisors translate shot life cycle state commands from the shot director into sequences of ''macro steps'' to be distributed to each of its shot supervisors. Each Shot supervisor maintains order of macro steps for each subsystem and supports collaboration between macro steps. They also manage failure, restarts and rejoining into the shot cycle (if necessary) and manage auto/manual macro step execution and collaborations between other collaboration supervisors. Shot supervisors execute macro step shot functions commanded by collaboration supervisors. Each macro step has database-driven verification phases and a scripted perform phase. This provides for a highly flexible methodology for performing a variety of NIF shot types. Database tables define the order of work and dependencies (workflow) of macro steps to be

  12. Reactive burn models and ignition & growth concept

    Directory of Open Access Journals (Sweden)

    Shaw M.S.

    2011-01-01

    Full Text Available Plastic-bonded explosives are heterogeneous materials. Experimentally, shock initiation is sensitive to small amounts of porosity, due to the formation of hot spots (small localized regions of high temperature. This leads to the Ignition & Growth concept, introduced by LeeTarver in 1980, as the basis for reactive burn models. A homo- genized burn rate needs to account for three meso-scale physical effects: (i the density of active hot spots or burn centers; (ii the growth of the burn fronts triggered by the burn centers; (iii a geometric factor that accounts for the overlap of deflagration wavelets from adjacent burn centers. These effects can be combined and the burn model defined by specifying the reaction progress variable λ = g(s as a function of a dimensionless reaction length s(t = rbc/ℓbc, rather than by specifying an explicit burn rate. The length scale ℓbc(Ps = [Nbc(Ps]−1/3 is the average distance between burn centers, where Nbc is the number density of burn centers activated by the lead shock. The reaction length rbc(t = ∫t0 D(P(t′dt′ is the distance the burn front propagates from a single burn center, where D(P is the deflagration speed as a function of the local pressure and t is the time since the shock arrival. A key implementation issue is how to determine the lead shock strength in conjunction with a shock capturing scheme. We have developed a robust algorithm for this purpose based on the Hugoniot jump condition for the energy. The algorithm utilizes the time dependence of density, pressure and energy within each cell. The method is independent of the numerical dissipation used for shock capturing. It is local and can be used in one or more space dimensions. The burn model has a small number of parameters which can be calibrated to fit velocity gauge data from shock initiation experiments.

  13. Reactive burn models and ignition & growth concept

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph S [Los Alamos National Laboratory; Shaw, Milton S [Los Alamos National Laboratory

    2010-01-01

    Plastic-bonded explosives are heterogeneous materials. Experimentally, shock initiation is sensitive to small amounts of porosity, due to the formation of hot spots (small localized regions of high temperature). This leads to the Ignition and Growth concept, introduced by Lee and Tarver in 1980, as the basis for reactive burn models. A homogeneized burn rate needs to account for three mesoscale physical effects (i) the density of burnt hot spots, which depends on the lead shock strength; (ii) the growth of the burn fronts triggered by hot spots, which depends on the local deflagration speed; (iii) a geometric factor that accounts for the overlap of deflagration wavelets from adjacent hot spots. These effects can be combined and the burn model defined by specifying the reaction progress variable {lambda}(t) as a function of a dimensionless reaction length {tau}{sub hs}(t)/{ell}{sub hs}, rather than by xpecifying an explicit burn rate. The length scale {ell}{sub hs} is the average distance between hot spots, which is proportional to [N{sub hs}(P{sub s})]{sup -1/3}, where N{sub hs} is the number density of hot spots activated by the lead shock. The reaction length {tau}{sub hs}(t) = {line_integral}{sub 0}{sup t} D(P(t'))dt' is the distance the burn front propagates from a single hot spot, where D is the deflagration speed and t is the time since the shock arrival. A key implementation issue is how to determine the lead shock strength in conjunction with a shock capturing scheme. They have developed a robust algorithm for this purpose based on the Hugoniot jump condition for the energy. The algorithm utilizes the time dependence of density, pressure and energy within each cell. The method is independent of the numerical dissipation used for shock capturing. It is local and can be used in one or more space dimensions. The burn model has a small number of parameters which can be calibrated to fit velocity gauge data from shock initiation experiments.

  14. Extrastriatal binding of [{sup 123}I]FP-CIT in the thalamus and pons: gender and age dependencies assessed in a European multicentre database of healthy controls

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Walter; Unterrainer, Marcus; Xiong, Guoming; Bartenstein, Peter [University of Munich, Department of Nuclear Medicine, Munich (Germany); Diemling, Markus [Hermes Medical Solutions, Stockholm (Sweden); Varrone, Andrea [Karolinska University Hospital, Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm (Sweden); Dickson, John C. [UCLH NHS Foundation Trust and University College, Institute of Nuclear Medicine, London (United Kingdom); Tossici-Bolt, Livia [University Hospitals Southampton NHS Trust, Department of Medical Physics, Southampton (United Kingdom); Sera, Terez [University of Szeged, Department of Nuclear Medicine and Euromedic Szeged, Szeged (Hungary); Asenbaum, Susanne [Medical University of Vienna, Department of Neurology, Vienna (Austria); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Centre, Amsterdam (Netherlands); Kapucu, Ozlem L. [Gazi University, Department of Nuclear Medicine, Faculty of Medicine, Ankara (Turkey); Kluge, Andreas [ABX-CRO, Dresden (Germany); Ziebell, Morten [Rigshospitalet and University of Copenhagen, Neurobiology Research Unit, Copenhagen (Denmark); Darcourt, Jacques [University of Nice-Sophia Antipolis, Nuclear Medicine Department, Centre Antoine Lacassagne, Nice (France); Nobili, Flavio [University of Genoa, Clinical Neurology Unit, Department of Neuroscience (DINOGMI), Genoa (Italy); Pagani, Marco [CNR, Institute of Cognitive Sciences and Technologies, Rome (Italy); Karolinska Hospital, Department of Nuclear Medicine, Stockholm (Sweden); Hesse, Swen [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Leipzig University Medical Centre, Molecular Neuroimaging IFB Adiposity Diseases, Leipzig (Germany); Borght, Thierry Vander [Universite Catholique de Louvain, Nuclear Medicine Division, CHU Dinant Godinne, Yvoir (Belgium); Laere, Koen van [University Hospital and K.U. Leuven, Nuclear Medicine, Leuven (Belgium); Tatsch, Klaus [Staedtisches Klinikum Karlsruhe, Department of Nuclear Medicine, Karlsruhe (Germany); La Fougere, Christian [University of Munich, Department of Nuclear Medicine, Munich (Germany); University of Tuebingen, Department of Nuclear Medicine, Tuebingen (Germany)

    2014-10-15

    Apart from binding to the dopamine transporter (DAT), [{sup 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 extrastriatal binding (predominantly due to SERT) and its age and gender dependencies in a large cohort of healthy controls. SPECT data from 103 healthy controls with well-defined criteria of normality acquired at 13 different imaging centres were analysed for extrastriatal binding using volumes of interest analysis for the thalamus and the pons. Data were examined for gender and age effects as well as for potential influence of striatal DAT radiotracer binding. Thalamic binding was significantly higher than pons binding. Partial correlations showed an influence of putaminal DAT binding on measured binding in the thalamus but not on the pons. Data showed high interindividual variation in extrastriatal binding. Significant gender effects with 31 % higher binding in women than in men were observed in the thalamus, but not in the pons. An age dependency with a decline per decade (±standard error) of 8.2 ± 1.3 % for the thalamus and 6.8 ± 2.9 % for the pons was shown. 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 [{sup 123}I]FP-CIT scans in healthy controls. For both the thalamus and the pons, an age-related decline in radiotracer binding was observed. Gender effects were demonstrated for binding in the thalamus only. As a potential clinical application, the data could be used as a reference to estimate SERT occupancy in addition to nigrostriatal integrity when using [{sup 123}I]FP-CIT for DAT imaging in patients treated with selective serotonin reuptake inhibitors. (orig.)

  15. Sodium citrate (Na{sub 3}Cit)-assisted hydrothermal synthesis of uniform spindle-like SrMoO{sub 4}:Eu{sup 3+} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Xiaolei; Zhang, Yu; Li, Qiuyu; Yu, Min, E-mail: yum406@nenu.edu.cn

    2014-11-15

    Graphical abstract: A facile hydrothermal method for the synthesis of uniform spindle-like SrMoO{sub 4}:Eu{sup 3+} phosphors with the assistance of sodium citrate (Na{sub 3}Cit). - Highlights: • Well-crystallized spindle-like SrMoO{sub 4}:Eu{sup 3+} phosphors have been synthesized. • The influence of the reaction temperature and reaction time were clearly shown. • The dosage of Na{sub 3}Cit has a strong effect on the spindle-like SrMoO{sub 4}:Eu{sup 3+} phosphors. • The growth mechanism for the formation of final samples was proposed. - Abstract: Highly uniform spindle-like SrMoO{sub 4}:Eu{sup 3+} phosphors have been prepared by a facile hydrothermal method using sodium citrate (Na{sub 3}Cit) as the chelating reagent. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrum (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Fourier transform-infrared spectroscopy (FT-IR) and photoluminescence spectra (PL) were used to characterize the resulting samples. The dosage of sodium citrate, reaction temperature and reaction time play key roles in the formation of the final samples. The possible formation mechanism for SrMoO{sub 4}:Eu{sup 3+} phosphors has been proposed. Upon excitation by ultraviolet radiation, the as-synthesized SrMoO{sub 4}:Eu{sup 3+} phosphors show the characteristic {sup 5}D{sub 0}–{sup 7}F{sub J} (J = 1, 2, 3, 4) emission lines with red emission {sup 5}D{sub 0}–{sup 7}F{sub 2} (613 nm) as the most prominent group.

  16. Warm compaction powder metallurgy of Cu

    Institute of Scientific and Technical Information of China (English)

    NGAI Tungwai Leo; WANG Shang-lin; LI Yuan-yuan; ZHOU Zho-yao; CHEN Wei-ping

    2005-01-01

    A series of experiments were carried out using different admixed lubricant contents,different compaction pressures and temperatures in order to study the warm compaction of copper powder.Results show that too much admixed lubricant will lead to the squeeze out of the lubricant from the compact during the warm compaction processing of Cu powder.Results also show that blisters can be found in sintered samples that contain lubricant less than 0.15% (mass fraction).Optimal warm compaction parameters for producing high density powder metallurgy copper material are obtained.Compacts with green density of 8.6 g/cm3 and a sintered density of 8.83 g/cm3 can be produced by warm compacting the Cu powder,which contains 0.2% admixed lubricant,and is compacted at 145 ℃ with a pressure of 700 Mpa.

  17. Improved dopamine transporter binding activity after bone marrow mesenchymal stem cell transplantation in a rat model of Parkinson's disease: small animal positron emission tomography study with F-18 FP-CIT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Bok-Nam; Lee, Kwanjae; An, Young-Sil [School of Medicine, Ajou University, Department of Nuclear Medicine and Molecular Imaging, Woncheon-dong, Yeongtong-gu, Gyeonggi-do, Suwon (Korea, Republic of); Kim, Jang-Hee; Park, So Hyun [Ajou University School of Medicine, Department of Pathology, Suwon (Korea, Republic of)

    2015-05-01

    We evaluated the effects of bone marrow-derived mesenchymal stem cells (BMSCs) in a model of Parkinson's disease (PD) using serial F-18 fluoropropylcarbomethoxyiodophenylnortropane (FP-CIT) PET. Hemiparkinsonian rats were treated with intravenously injected BMSCs, and animals without stem cell therapy were used as the controls. Serial FP-CIT PET was performed after therapy. The ratio of FP-CIT uptake in the lesion side to uptake in the normal side was measured. The changes in FP-CIT uptake were also analyzed using SPM. Behavioural and histological changes were observed using the rotational test and tyrosine hydroxylase (TH)-reactive cells. FP-CIT uptake ratio was significantly different in the BMSCs treated group (n = 28) at each time point. In contrast, there was no difference in the ratio in control rats (n = 25) at any time point. SPM analysis also revealed that dopamine transporter binding activity was enhanced in the right basal ganglia area in only the BMSC therapy group. In addition, rats that received BMSC therapy also exhibited significantly improved rotational behaviour and preservation of TH-positive neurons compared to controls. The therapeutic effect of intravenously injected BMSCs in a rat model of PD was confirmed by dopamine transporter PET imaging, rotational functional studies, and histopathological evaluation. (orig.)

  18. Some aspects of the aqueous solution chemistry of the Na+/Ca2+/OH-/Cit3- system: The structure of a new calcium citrate complex forming under hyperalkaline conditions

    Science.gov (United States)

    Gácsi, Attila; Kutus, Bence; Buckó, Ákos; Csendes, Zita; Peintler, Gábor; Pálinkó, István; Sipos, Pál

    2016-08-01

    In the present study, we show that in hyperalkaline (pH > 13) aqueous solutions, Ca2+ forms a new, so far unknown complex species with the citrate ion, the structure of which is different from the well-known CaCit-(aq) species present in solutions of close to neutral pH. The solubility of Ca3Cit2(s) was found to increase significantly under hyperalkaline conditions. The decrease in the electric conductivity and the variations observed in the freezing point depression of such solutions also indicate complexation. From 1H NMR measurements, in this complex, the citrate ion is suggested to be in quadruply deprotonated form. From the variation of the 2JHH geminal proton coupling constant, two neighboring carboxylate groups are coordinated to the calcium ion in a monodentate mode (besides the alcoholate). The optimal structure of the complex with the composition of CaCitH-12-(aq) has also been calculated using DFT calculations, applying the Polarizable Continuum Model. Sodium ion-pairing was found to compete efficiently with this calcium complexation process, and in solutions with high Na-ion content, the equilibria are shifted towards the formation of NaCit2-(aq) and Na2Cit-(aq) ion pairs.

  19. Implementation of the European multicentre database of healthy controls for [{sup 123}I]FP-CIT SPECT increases diagnostic accuracy in patients with clinically uncertain parkinsonian syndromes

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Nathalie L.; Unterrainer, Marcus; Xiong, Guoming; Bartenstein, Peter; Koch, Walter [University of Munich, Department of Nuclear Medicine, Munich (Germany); Diemling, Markus [Hermes Medical Solutions, Stockholm (Sweden); Varrone, Andrea [Karolinska University Hospital, Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm (Sweden); Dickson, John C. [UCLH NHS Foundation Trust and University College, Institute of Nuclear Medicine, London (United Kingdom); Tossici-Bolt, Livia [University Hospitals Southampton NHS Trust, Department of Medical Physics, Southampton (United Kingdom); Sera, Terez [University of Szeged, Department of Nuclear Medicine and Euromedic Szeged, Szeged (Hungary); Asenbaum, Susanne [Medical University of Vienna, Department of Neurology, Vienna (Austria); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Centre, Amsterdam (Netherlands); Kapucu, L. Oezlem A. [Gazi University, Department of Nuclear Medicine, Faculty of Medicine, Ankara (Turkey); Kluge, Andreas [ABX-CRO, Dresden (Germany); Ziebell, Morten [Rigshospitalet and University of Copenhagen, Neurobiology Research Unit, Copenhagen (Denmark); Darcourt, Jacques [University of Nice-Sophia Antipolis, Nuclear Medicine Department, Centre Antoine Lacassagne, Nice (France); Nobili, Flavio [University of Genoa, Clinical Neurology Unit, Department of Neuroscience (DINOGMI), Genoa (Italy); Pagani, Marco [Institute of Cognitive Sciences and Technologies, CNR, Rome (Italy); Karolinska Hospital, Department of Nuclear medicine, Stockholm (Sweden); Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Hesse, Swen [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Leipzig University Medical Centre, Molecular Neuroimaging IFB Adiposity Diseases, Leipzig (Germany); Borght, Thierry vander [Universite Catholique de Louvain, Nuclear Medicine Division, Mont-Godinne Medical Center, Yvoir (Belgium); Laere, Koen van [University Hospital and K.U. Leuven, Nuclear Medicine, Leuven (Belgium); Tatsch, Klaus [Staedtisches Klinikum Karlsruhe, Department of Nuclear Medicine, Karlsruhe (Germany); La Fougere, Christian [University of Tuebingen, Division of Nuclear Medicine, Department of Radiology, Tuebingen (Germany)

    2016-07-15

    Even though [{sup 123}I]FP-CIT SPECT provides high accuracy in detecting nigrostriatal cell loss in neurodegenerative parkinsonian syndromes (PS), some patients with an inconclusive diagnosis remain. We investigated whether the diagnostic accuracy in patients with clinically uncertain PS with previously inconclusive findings can be improved by the use of iterative reconstruction algorithms and an improved semiquantitative evaluation which additionally implemented a correction algorithm for patient age and gamma camera dependency (EARL-BRASS; Hermes Medical Solutions, Sweden). We identified 101 patients with inconclusive findings who underwent an [{sup 123}I]FP-CIT SPECT between 2003 and 2010 as part of the diagnostic process of suspected PS at the University of Munich, and re-evaluated these scans using iterative reconstruction algorithms and the new corrected EARL-BRASS. Clinical follow-up was obtained in 62 out of the 101 patients and constituted the gold standard for the re-evaluation to assess the possible improvement in diagnostic accuracy. Clinical follow-up confirmed the diagnosis of PS in 11 of the 62 patients. In patients in whom both visual and semiquantitative analysis showed concordant findings (48 patients), a high negative predictive value (93 %), positive predictive value (100 %) and accuracy (94 %) were found, and thus a correct diagnosis was obtained in 45 of the 48 patients. Among the 14 patients with discordant findings, the additional semiquantitative analysis correctly identified all five of nine patients patients without PS by nonpathological semiquantitative findings in visually pathological or inconclusive scans. In contrast, four of the remaining five patients with decreased semiquantitative values but visually normal scans did not show a PS during follow-up. The age-corrected and camera-corrected mode of evaluation using EARL-BRASS provided a notable improvement in the diagnostic accuracy of [{sup 123}I]FP-CIT SPECT in PS patients with

  20. Comparison of the performance of {sup 18}F-FP-CIT brain PET/MR and simultaneous PET/CT: A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Sang Don; Chun, Kyung Ah [Dept. of Nuclear Medicine, Yeungnam University Hospital, Daegu (Korea, Republic of)

    2016-09-15

    {sup 18}F-FP-CIT [{sup 1'}8F-fluorinated N-3-fluoropropyl-2-beta-carboxymethoxy-3-beta-(4-iodophenyl) nortropane] has been well established and used for the differential diagnosis of atypical parkinsonian disorders. Recently, combined positron emission tomography (PET)/magnetic resonance (MR) was proposed as a viable alternative to PET/computed tomography (CT). The aim of this study was to compare the performances of conventional {sup 18}F-FP-CIT brain PET/CT and simultaneous PET/MR by visual inspection and quantitative analysis. Fifteen consecutive patients clinically suspected of having Parkinson's disease were recruited for the study.{sup 18}F-FP-CIT PET was performed during PET/CT and PET/MR. PET/CT image acquisition was started 90 min after intravenous injection of {sup 18}F-FP-CIT and then PET/MR images were acquired. Dopamine transporter (DAT) density in bilateral striatal subregions was assessed visually. Quantitative analyses were performed on bilateral striatal volumes of interest (VOIs) using average standardized uptake values (SUVmeans). Intraclass correlation coefficients (ICCs) and their 95 % confidence intervals (CIs) were assessed to compare PET/CT and PET/MR data. Bland-Altman plots were drawn to perform method-comparisons. All subjects showed a preferential decrease in DAT binding in the posterior putamen (PP), with relative sparing of the ventral putamen (VP). Bilateral striatal subregional binding ratio (BR) determined PET/CT and PET/MR demonstrated close interequipment correspondence (BRright caudate - ICC, 0.944; 95 % CI, 0.835-0.981, BRleft caudate - ICC, 0.917; 95 % CI, 0.753-0.972, BRright putamen - ICC, 0.976; 95 % CI, 0.929-0.992 and BRleft putamen - ICC, 0.970; 95 % CI, 0.911-0.990, respectively), and Bland-Altman plots showed interequipment agreement between the two modalities. It is known that MR provides more information about anatomical changes associated with brain diseases and to enable the anatomical allocations of

  1. Laser-induced multi-point ignition for enabling high-performance engines

    KAUST Repository

    Chung, Suk-Ho

    2015-01-01

    Various multi-point laser-induced ignition techniques were reviewed, which adopted conical cavity and prechamber configurations. Up to five-point ignitions have been achieved with significant reduction in combustion duration, demonstrating potential increase in combustion system efficiency.

  2. Development of a Novel Non-Equilibrium Pulsed Plasma Ignition Module for High Altitude Turbojets Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An experimental research program focusing on design, development, and testing of a novel nonequilibrium plasma ignition module is proposed. The ignition module will...

  3. Experimental study on ignition characteristics of pulverized coal under high-temperature oxygen condition

    Science.gov (United States)

    Liu, G. W.; Liu, Y. H.; Dong, P.

    2016-08-01

    The high-temperature oxygen ignition technology of pulverized coal, which can replace the oil gun and achieve oil-free pulverized coal ignition by mixing the high- temperature oxygen and the pulverized coal stream directly, was proposed and a relevant ignition experimental system was built. The ignition characteristics of pulverized coal under high-temperature oxygen condition were investigated: the ignition process was described and analyzed, the influence of relevant parameters on the pulverized coal stream ignition were obtained and analyzed. The results showed: when the oxygen heating temperature is over 750 °C, the pulverized coal stream could be ignited successfully by high-temperature oxygen; increasing the pulverized coal concentration, primary air temperature and oxygen volume flow rate or decreasing the primary air velocity is helpful for the ignition and combustion of the pulverized coal stream.

  4. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Duffy, Kevin P.; Kieser, Andrew J.; Rodman, Anthony; Liechty, Michael P.; Hergart, Carl-Anders; Hardy, William L.

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  5. Optical pulse generation system for the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Penko, F; Braucht,; Browning, D; Crane, J K; Dane, B; Deadrick, F; Dreifuerst, G; Henesian, M; Jones, B A; Kot, L; Laumann, C; Martinez, M; Moran, B; Rothenberg, J E; Skulina, K; Wilcox, R B

    1998-06-18

    We describe the Optical Pulse Generation (OPG) system for the National Ignition Facility ( NIF ). The OPG system begins with the Master Oscillator Room ( MOR ) where the initial, seed pulse for the entire laser system is produced and properly formatted to enhance ignition in the target. The formatting consists of temporally shaping the pulse and adding additional bandwidth to increase the coupling of the laser generated x-rays to the high density target plasma. The pulse produced in the MOR fans out to 48 identical preamplifier modules where it is amplified by a factor of ten billion and spatially shaped for injection into the 192 main amplifier chai

  6. Ignite HD采集和制作平台

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Thomson新推出的Ignite HD解决方案,包括Ignite SDC和HDC自动控制摄像系统。Ignite系列产品为控制室和新闻编辑室提供了完备的链路.并且使广播机构和视频制作公司利用新Kayak HD紧凑视频制作切换台,高效、节约地从SD过渡到HD。其中,Ignire HDC是全合一自动控制HD广播摄像系统。

  7. Ignition of Metal Powders in Combustion Products of Model Fuel

    Science.gov (United States)

    1974-11-13

    y AD/A-001 172 IGNITION OF METAL POWDERS IN COMBUSTION PRODUCTS OF MODEL FUEL A. K. Klyauzov, et al Foreign Technology...S. Air Force UNCLASSIFIED »b. s»ouc » "I»0«T TITLE IGNITION OF METAL POWDERS IN COMBUSTION PRODUCTS OF MODEL FUEL f* OCJCPIPTIVK NOTKI (Typ* o...report mnd Inclumiv «**»••) Translation S »UTMö«I|I ( Firn tSSS», rnlddl* Inltlml, faar .tarna; A. K. Klyauzov, M. M. Arsh, et al 6

  8. Role of fast ignitor in fast-shock ignition concept

    Directory of Open Access Journals (Sweden)

    S. A. Ghasemi

    2014-03-01

    Full Text Available This paper deals with the role of fast ignitor in fast-shock ignition (FSI concept. The semi-analytical model indicates that the FSI target gain is a function of fast ignitor laser wavelength. If the energy of fast ignitor driver is and the laser wavelength is less than 0.53 micron, then with a fuel mass about 2 mg the FSI has a considerable advantage over pure shock ignition and the figure of merit is better than 1.2. When the wavelength of fast ignitor becomes shorter, the approaches , and for wavelengths shorter than 0.25 micron no additional is advantage is obtained.

  9. Beryllium ignition target design for indirect drive NIF experiments

    Science.gov (United States)

    Simakov, A. N.; Wilson, D. C.; Yi, S. A.; Kline, J. L.; Salmonson, J. D.; Clark, D. S.; Milovich, J. L.; Marinak, M. M.

    2016-03-01

    Beryllium (Be) ablator offers multiple advantages over carbon based ablators for indirectly driven NIF ICF ignition targets. These are higher mass ablation rate, ablation pressure and ablation velocity, lower capsule albedo, and higher thermal conductivity at cryogenic temperatures. Such advantages can be used to improve the target robustness and performance. While previous NIF Be target designs exist, they were obtained a long time ago and do not incorporate the latest improved physical understanding and models based upon NIF experiments. Herein, we propose a new NIF Be ignition target design at 1.45 MJ, 430 TW that takes all this knowledge into account.

  10. Ús il·lícit i falsificació de targetes bancàries

    Directory of Open Access Journals (Sweden)

    Luis Ramón Ruiz

    2006-11-01

    Full Text Available

    Les targetes bancàries, de crèdit i de dèbit, han constitu¨t tradicionalment l'objecte central dels atacs no violents a patrimonis de les entitats bancàries i dels seus clients, a partir de la utilització de tecnologies basades en el desenvolupament de la informàtica i de les telecomunicacions. Si bé altres fraus i atacs patrimonials s'han sumat a aquestes pràctiques, el frau de targetes continua constituint una realitat criminològica de primer ordre.

    La resposta del dret penal a aquestes pràctiques ha anat mantenint una notable falta de sistemàtica, que en certa manera ha estat substitu¨da per l'actuació dels tribunals, els quals han anat distribuint la variada fenomenologia delictiva en els diferents tipus penals en els quals han encaixat millor. L'absència d'un delicte de frau amb targetes, la possibilitat d'actuar il·lícitament amb targetes reals o de confecció falsa, l'ús d'aquestes en caixers automàtics, en comerços o la seva numeració per Internet dificulten notablement la qualificació jurídica de les conductes. Els tribunals han anat aplicant els delictes de robatori amb força, estafa i estafa informàtica segons l'execució concreta de la conducta delictiva derivada de l'ús il·lícit de la targeta, si bé la voluntat de reduir al màxim els espais d'impunitat ha portat en algunes resolucions judicials a forçar la interpretació dels tipus penals més enllà de l'exigible.

    A això cal sumar-hi el tractament incongruent que el legislador ha donat a la falsificació de targetes bancàries, assimilant-la de forma genèrica a la falsificació de moneda, provocant una interpretació novament extensiva del Tribunal Suprem i assignant-li una penalitat sens dubte desorbitada.

    El recurs al principi de legalitat i al de protecció exclusiva de béns jurídics s'imposa en una matèria normativament confusa i amb un tractament judicial erràtic.

  11. Saint-Junien début de siècle, à travers trois récits distincts

    Directory of Open Access Journals (Sweden)

    Vincent Brousse

    2008-11-01

    Full Text Available À partir de trois récits distincts étalés sur 60 ans et tous relatifs à une période très brève de l’histoire, au début du xxe siècle, d’une ville industrielle du Limousin, Saint-Junien, il s’agit de confronter trois points de vue, celui d’un prêtre Simon Delort, celui d’un militant de l’Action française Georges Gaudy, et celui d’un militant anarchiste Jean Bourgoin. Le propos vise à interroger la présentation historique de la ville, sa construction mémorielle, certains de ses acteurs de premier plan, et l’émergence d’une société nouvelle en construction où les libertaires semblent, un instant, jouer le premier rôle. Cela permet aussi de comprendre pourquoi aujourd’hui, toujours municipalité communiste, depuis 87 ans, Saint-Junien est demeurée « la ville rouge ».This paper is based on three different stories, written over 60 years, and all three related to a very short period of the xxth-century-history of Saint-Junien, an industrial town in Limousin. Three different points of view are compared : fromSimon Delort, a priest ; from Georges Gaudy an Action-Française militant, and from Jean Bourgoin, an anarchist militant.We aim at tackling the historical presentation of the town, its memorial construction, some of its first-rank actors, and the rising up of a new society where the Libertarians played the first part for a very short time. This paper is also the occasion to understand how Saint-Junien has remained a Communist town for 87 years and is still named « the red town ».

  12. Equationally Compact Acts : Coproducts / Peeter Normak

    Index Scriptorium Estoniae

    Normak, Peeter

    1998-01-01

    In this article equational compactness of acts and its generalizations are discussed. As equational compactness does not carry over to coproducts a slight generalization of c-equational campactness is introduced. It is proved that a coproduct of acts is c-equationally compact if and only if all components are c-equationally campact

  13. The Kolmogorov-Riesz compactness theorem

    CERN Document Server

    Hanche-Olsen, Harald

    2009-01-01

    We show that the Arzela-Ascoli theorem and Kolmogorov compactness theorem both are consequences of a simple lemma on compactness in metric spaces. Their relation to Helly's theorem is discussed. The paper contains a detailed discussion on the historical background of the Kolmogorov compactness theorem.

  14. Formation and evolution of compact binaries

    NARCIS (Netherlands)

    Sluijs, Marcel Vincent van der

    2006-01-01

    In this thesis we investigate the formation and evolution of compact binaries. Chapters 2 through 4 deal with the formation of luminous, ultra-compact X-ray binaries in globular clusters. We show that the proposed scenario of magnetic capture produces too few ultra-compact X-ray binaries to explain

  15. Storage Reliability of Missile Materiel Program. Igniters and Safe and Arm Device Analysis.

    Science.gov (United States)

    1976-05-01

    currenk is applied to the squibs which ignite the pyrogen motor. Hot gases from the pyrogen motor exhaust up the blast tube to the rocket motor...acts as a back- up in case of failure of the primary ignition spark plug. The hot gas igniter has a burn-time of 80 to 100 milliseconds. It consists of...Reliability The data collected todate indicates two separate character- istics effecting the reliability of igniters and safe and arm devices. The first

  16. Photothermal Deoxygenation of Graphene Oxide for Distributed Ignition and Patterning Applications (Postprint)

    Science.gov (United States)

    2010-01-01

    and in high efficiency homogenous charge compression ignition ( HCCI ) engines , where ignition control is of paramount importance. 15. SUBJECT TERMS... HCCI ) engine that combines the high efficiency of a diesel engine with the low emissions of a spark ignition engine . In a typical HCCI engine , fuel... engine .[40] The high compression ratio of HCCI engines provides an efficiency increase of up to 15% over traditional spark ignition engines .[41,42

  17. CitEST libraries

    Directory of Open Access Journals (Sweden)

    Maria Luísa P. Natividade Targon

    2007-01-01

    Full Text Available In order to obtain a better understanding of what is citrus, 33 cDNA libraries were constructed from different citrus species and genera. Total RNA was extracted from fruits, leaves, flowers, bark, seeds and roots, and subjected or not to different biotic and abiotic stresses (pathogens and drought and at several developmental stages. To identify putative promoter sequences, as well as molecular markers that could be useful for breeding programs, one shotgun library was prepared from sweet orange (Citrus sinensis var. Olimpia. In addition, EST libraries were also constructed for a citrus pathogen, the oomycete Phythophthora parasitica in either virulent or avirulent form. A total of 286,559 cDNA clones from citrus were sequenced from their 5’ end, generating 242,790 valid reads of citrus. A total of 9,504 sequences were produced in the shotgun library and the valid reads were assembled using CAP3. In this procedure, we obtained 1,131 contigs and 4,083 singletons. A total of 19,200 cDNA clones from P. parasitica were sequenced, resulting in 16,400 valid reads. The number of ESTs generated in this project is, to our knowledge, the largest citrus sequence database in the world.

  18. Compact differences of composition operators

    CERN Document Server

    Heller, Katherine; Weir, Rachel J

    2010-01-01

    When $\\varphi$ and $\\psi$ are linear-fractional self-maps of the unit ball $B_N$ in ${\\mathbb C}^N$, $N\\geq 1$, we show that the difference $C_{\\varphi}-C_{\\psi}$ cannot be non-trivially compact on either the Hardy space $H^2(B_N)$ or any weighted Bergman space $A^2_{\\alpha}(B_N)$. Our arguments emphasize geometrical properties of the inducing maps $\\varphi$ and $\\psi$.

  19. Weak compactness of biharmonic maps

    Directory of Open Access Journals (Sweden)

    Shenzhou Zheng

    2012-10-01

    Full Text Available This article shows that if a sequence of weak solutions of a perturbed biharmonic map satisfies $Phi_ko 0$ in $(W^{2,2}^*$ and $u_kightharpoonup u$ weakly in $W^{2,2}$, then $u$ is a biharmonic map. In particular, we show that the space of biharmonic maps is sequentially compact under the weak-$W^{2,2}$ topology.

  20. Multipole structure of compact objects

    CERN Document Server

    Quevedo, Hernando

    2016-01-01

    We analyze the applications of general relativity in relativistic astrophysics in order to solve the problem of describing the geometric and physical properties of the interior and exterior gravitational and electromagnetic fields of compact objects. We focus on the interpretation of exact solutions of Einstein's equations in terms of their multipole moments structure. In view of the lack of physical interior solutions, we propose an alternative approach in which higher multipoles should be taken into account.

  1. Target-local Gromov compactness

    CERN Document Server

    Fish, Joel W

    2009-01-01

    We prove a version of Gromov's compactness theorem for pseudo-holomorphic curves which holds locally in the target symplectic manifold. This result applies to sequences of curves with an unbounded number of free boundary components, and in families of degenerating target manifolds which have unbounded geometry (e.g. no uniform energy threshold). Core elements of the proof regard curves as submanifolds (rather than maps) and then adapt methods from the theory of minimal surfaces.

  2. Ignition et oxydation des particules de combustible solide pulvérisé Ignition and Oxidation of Pulverized Solid Fuel

    Directory of Open Access Journals (Sweden)

    De Soete G. G.

    2006-11-01

    Full Text Available On présente dans cet article, en utilisant la méthode du ruban chauffé, une étude de la compétition entre (1 la dévolatilisation et l'oxydation consécutive des produits de pyrolyse et (2 l'ignition de la matrice solide et sa combustion rapide. La comparaison entre le moment de l'ignition et le début de la pyrolyse permet de déterminer en fonction de la température, de la taille des particules et de la concentration en oxygène, le domaine dans lequel l'ignition d'un combustible solide pyrolysable est du type whole coal ignition (c'est-à-dire lorsque l'ignition intervient avant que la pyrolyse devienne mesurable. Les résultats suggèrent que ce type d'ignition doit s'effectuer en règle générale dans les conditions de mise en oeuvre des combustibles solides pulvérisés dans les flammes industrielles. Dans le cas de l'ignition whole coal , la vitesse de combustion de la matrice solide est inhibée dans la période qui suit l'ignition. Cette inhibition est due d'une part à la difficulté pour l'oxygène de diffuser dans les pores pendant la sortie des produits de pyrolyse, et d'autre part à la consommation préférentielle de l'oxygène dans l'oxydation des produits de pyrolyse, principalement dans le cas où cette oxydation se développe sous forme de flamme. Ce n'est que lorsque la pyrolyse s'achève que la vitesse de combustion hétérogène peut atteindre sa valeur stationnaire normale, qui est alors pratiquement identique à celle du coke. Aux températures situées entre la température d'ignition du combustible solide et la température d'extinction du coke résiduel, la combustion est incomplète, une extinction intervenant à un degré de dévolatilisation d'autant plus grande que la température est élevée. Ce phénomène s'explique qualitativement par la théorie classique d'ignition thermique lorsqu'on l'applique au cas particulier des combustibles solides pyrolysables. Les températures d'ignition ainsi que les d

  3. Comminution circuits for compact itabirites

    Directory of Open Access Journals (Sweden)

    Pedro Ferreira Pinto

    Full Text Available Abstract In the beneficiation of compact Itabirites, crushing and grinding account for major operational and capital costs. As such, the study and development of comminution circuits have a fundamental importance for feasibility and optimization of compact Itabirite beneficiation. This work makes a comparison between comminution circuits for compact Itabirites from the Iron Quadrangle. The circuits developed are: a crushing and ball mill circuit (CB, a SAG mill and ball mill circuit (SAB and a single stage SAG mill circuit (SSSAG. For the SAB circuit, the use of pebble crushing is analyzed (SABC. An industrial circuit for 25 million tons of run of mine was developed for each route from tests on a pilot scale (grinding and industrial scale. The energy consumption obtained for grinding in the pilot tests was compared with that reported by Donda and Bond. The SSSAG route had the lowest energy consumption, 11.8kWh/t and the SAB route had the highest energy consumption, 15.8kWh/t. The CB and SABC routes had a similar energy consumption of 14.4 kWh/t and 14.5 kWh/t respectively.

  4. Strings in compact cosmological spaces

    CERN Document Server

    Craps, Ben; Konechny, Anatoly

    2013-01-01

    We confront the problem of giving a fundamental definition to perturbative string theory in spacetimes with totally compact space (taken to be a torus for simplicity, though the nature of the problem is very general) and non-compact time. Due to backreaction induced by the presence of even a single string quantum, the usual formulation of perturbative string theory in a fixed classical background is infrared-divergent at all subleading orders in the string coupling, and needs to be amended. The problem can be seen as a closed string analogue of D0-brane recoil under an impact by closed strings (a situation displaying extremely similar infrared divergences). Inspired by the collective coordinate treatment of the D0-brane recoil, whereby the translational modes of the D0-brane are introduced as explicit dynamical variables in the path integral, we construct a similar formalism for the case of string-induced gravitational backreaction, in which the spatially uniform modes of the background fields on the compact ...

  5. 78 FR 61384 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Science.gov (United States)

    2013-10-03

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... of this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  6. 78 FR 20355 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Science.gov (United States)

    2013-04-04

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  7. 77 FR 60475 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Science.gov (United States)

    2012-10-03

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... of this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  8. 76 FR 20044 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Science.gov (United States)

    2011-04-11

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  9. 75 FR 62568 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Science.gov (United States)

    2010-10-12

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  10. 76 FR 66326 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Science.gov (United States)

    2011-10-26

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  11. 77 FR 20051 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Science.gov (United States)

    2012-04-03

    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  12. Experimental Study of Ignition over Impact-Driven Supersonic Liquid Fuel Jet

    Directory of Open Access Journals (Sweden)

    Anirut Matthujak

    2013-01-01

    Full Text Available This study experimentally investigates the mechanism of the ignition of the supersonic liquid fuel jet by the visualization. N-Hexadecane having the cetane number of 100 was used as a liquid for the jet in order to enhance the ignition potential of the liquid fuel jet. Moreover, the heat column and the high intensity CO2 laser were applied to initiate the ignition. The ignition over the liquid fuel jet was visualized by a high-speed digital video camera with a shadowgraph system. From the shadowgraph images, the autoignition or ignition of the supersonic liquid fuel jet, at the velocity of 1,186 m/s which is a Mach number relative to the air of 3.41, did not take place. The ignition still did not occur, even though the heat column or the high intensity CO2 laser was alone applied. The attempt to initiate the ignition over the liquid fuel jet was achieved by applying both the heat column and the high intensity CO2 laser. Observing the signs of luminous spots or flames in the shadowgraph would readily indicate the presence of ignitions. The mechanism of the ignition and combustion over the liquid fuel jet was clearly clarified. Moreover, it was found that the ignition over the supersonic liquid fuel jet in this study was rather the force ignition than being the auto-ignition induced by shock wave heating.

  13. Passive, Low Cost Neutron Detectors for Neutron Diagnostics at the National Ignition Facility

    Science.gov (United States)

    2013-03-01

    1  1.1  NIF Collaboration and Problem Identification ....................................................1  1.2  Statement of Short and Long Term...Momentum Change During De-Excitation n Electron Shell Designation or Empirical Constant for Electron Range NIF National Ignition...DIAGNOSTICS AT THE NATIONAL IGNITION FACILITY I. Introduction 1.1 NIF Collaboration and Problem Identification The National Ignition

  14. Photothermal Deoxygenation of Graphene Oxide to Graphitic Carbon for Distributed Ignition and Patterning Applications (Preprint)

    Science.gov (United States)

    2009-04-13

    liquid fuel rocket engines and in high efficiency homogenous charge compression ignition ( HCCI ) engines , where ignition control is of paramount importance...distributed ignition” has applications in liquid fuel rocket engines and in high efficiency homogenous charge compression ignition ( HCCI ) engines , where... HCCI engine application: Over the last decade, extraordinary effort has been undertaken to both improve the fuel efficiency in

  15. Motion Analysis of Fiber Band in Compact Field of Compact Spinning

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The technological process of compact spinning and the compact procedure of fiber band in compact field are briefly illustrated. The motions of fiber band in compact field are discussed theoretically from which tilting angle of suction slot in profile tube, additional twists created by fiber band's rotating around its own axis and ultimate twists in compact yarn are deduced accordingly. The existence of additional twists is also verified through experiments.

  16. Ignition delay time measurements of primary reference fuel blends

    KAUST Repository

    Alabbad, Mohammed

    2017-02-07

    Ignition delay times of four different primary reference fuels (PRF), mixtures of n-heptane and iso-octane, were measured behind reflected shock waves in a high-pressure shock tube facility. The PRFs were formulated to match the RON of two high-octane gasolines (RON 95 and 91) and two prospective low-octane naphtha fuels (RON 80 and 70). Experiments were carried out over a wide range of temperatures (700–1200K), pressures (10, 20, and 40bar) and equivalence ratios (0.5 and 1). Kinetic modeling predictions from four chemical kinetic mechanisms are compared with the experimental data. Ignition delay correlations are developed to reproduce the measured ignition delay times. Brute force sensitivity analyses are carried out to identify reactions that affect ignition delay times at specific temperature, pressure and equivalence ratio. The large experimental data set provided in the current work will serve as a benchmark for the validation of chemical kinetic mechanisms of primary reference fuel blends.

  17. Computational Modeling in Support of the National Ignition Facilty Operations

    CERN Document Server

    Shaw, M J; Haynam, C A; Williams, W H

    2001-01-01

    Numerical simulation of the National Ignition Facility (NIF) laser performance and automated control of the laser setup process are crucial to the project's success. These functions will be performed by two closely coupled computer code: the virtual beamline (VBL) and the laser performance operations model (LPOM).

  18. Computational Modeling in Support of National Ignition Facility Operations

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M J; Sacks, R A; Haynam, C A; Williams, W H

    2001-10-23

    Numerical simulation of the National Ignition Facility (NIF) laser performance and automated control of laser setup process are crucial to the project's success. These functions will be performed by two closely coupled computer codes: the virtual beamline (VBL) and the laser operations performance model (LPOM).

  19. 49 CFR 192.751 - Prevention of accidental ignition.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Prevention of accidental ignition. 192.751 Section 192.751 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.751 Prevention...

  20. Cone-guided fast ignition with no imposed magnetic fields

    Directory of Open Access Journals (Sweden)

    Strozzi D.

    2013-11-01

    Full Text Available Simulations are presented of ignition-scale fast ignition targets with the integrated Zuma-Hydra PIC-hydrodynamic capability. We consider a spherical DT fuel assembly with a carbon cone, and an artificially-collimated fast electron source. We study the role of E and B fields and the fast electron energy spectrum. For mono-energetic 1.5 MeV fast electrons, without E and B fields, ignition can be achieved with fast electron energy Efig = 30kJ. This is 3.5× the minimal deposited ignition energy of 8.7 kJ for our fuel density of 450 g/cm3. Including E and B fields with the resistive Ohm's law E = ηJb gives Efig = 20kJ, while using the full Ohm's law gives Efig > 40 kJ. This is due to magnetic self-guiding in the former case, and ∇n ×∇T magnetic fields in the latter. Using a realistic, quasi two-temperature energy spectrum derived from PIC laser-plasma simulations increases Efig to (102, 81, 162 kJ for (no E/B, E = ηJb, full Ohm's law. Such electrons are too energetic to stop in the optimal hot spot depth.

  1. Knock Prediction Using a Simple Model for Ignition Delay

    KAUST Repository

    Kalghatgi, Gautam

    2016-04-05

    An earlier paper has shown the ability to predict the phasing of knock onset in a gasoline PFI engine using a simple ignition delay equation for an appropriate surrogate fuel made up of toluene and PRF (TPRF). The applicability of this approach is confirmed in this paper in a different engine using five different fuels of differing RON, sensitivity, and composition - including ethanol blends. An Arrhenius type equation with a pressure correction for ignition delay can be found from interpolation of previously published data for any gasoline if its RON and sensitivity are known. Then, if the pressure and temperature in the unburned gas can be estimated or measured, the Livengood-Wu integral can be estimated as a function of crank angle to predict the occurrence of knock. Experiments in a single cylinder DISI engine over a wide operating range confirm that this simple approach can predict knock very accurately. The data presented should enable engineers to study knock or other auto-ignition phenomena e.g. in premixed compression ignition (PCI) engines without explicit chemical kinetic calculations. © Copyright 2016 SAE International.

  2. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Science.gov (United States)

    2010-07-01

    ...-constantan or chromelalumel—and a potentiometer shall be used for all temperature measurements. (3) Syringe...) Temperature control. Each autotransformer shall be so adjusted that the temperature at the neck, mid-section... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Autogenous-ignition temperature test....

  3. The first experiments on the national ignition facility

    Science.gov (United States)

    Landen, O. L.; Glenzer, S.; Froula, D.; Dewald, E.; Suter, L. J.; Schneider, M.; Hinkel, D.; Fernandez, J.; Kline, J.; Goldman, S.; Braun, D.; Celliers, P.; Moon, S.; Robey, H.; Lanier, N.; Glendinning, G.; Blue, B.; Wilde, B.; Jones, O.; Schein, J.; Divol, L.; Kalantar, D.; Campbell, K.; Holder, J.; McDonald, J.; Niemann, C.; MacKinnon, A.; Collins, R.; Bradley, D.; Eggert, J.; Hicks, D.; Gregori, G.; Kirkwood, R.; Niemann, C.; Young, B.; Foster, J.; Hansen, F.; Perry, T.; Munro, D.; Baldis, H.; Grim, G.; Heeter, R.; Hegelich, B.; Montgomery, D.; Rochau, G.; Olson, R.; Turner, R.; Workman, J.; Berger, R.; Cohen, B.; Kruer, W.; Langdon, B.; Langer, S.; Meezan, N.; Rose, H.; Still, B.; Williams, E.; Dodd, E.; Edwards, J.; Monteil, M.-C.; Stevenson, M.; Thomas, B.; Coker, R.; Magelssen, G.; Rosen, P.; Stry, P.; Woods, D.; Weber, S.; Alvarez, S.; Armstrong, G.; Bahr, R.; Bourgade, J.-L.; Bower, D.; Celeste, J.; Chrisp, M.; Compton, S.; Cox, J.; Constantin, C.; Costa, R.; Duncan, J.; Ellis, A.; Emig, J.; Gautier, C.; Greenwood, A.; Griffith, R.; Holdner, F.; Holtmeier, G.; Hargrove, D.; James, T.; Kamperschroer, J.; Kimbrough, J.; Landon, M.; Lee, D.; Malone, R.; May, M.; Montelongo, S.; Moody, J.; Ng, E.; Nikitin, A.; Pellinen, D.; Piston, K.; Poole, M.; Rekow, V.; Rhodes, M.; Shepherd, R.; Shiromizu, S.; Voloshin, D.; Warrick, A.; Watts, P.; Weber, F.; Young, P.; Arnold, P.; Atherton, L.; Bardsley, G.; Bonanno, R.; Borger, T.; Bowers, M.; Bryant, R.; Buckman, S.; Burkhart, S.; Cooper, F.; Dixit, S.; Erbert, G.; Eder, D.; Ehrlich, B.; Felker, B.; Fornes, J.; Frieders, G.; Gardner, S.; Gates, C.; Gonzalez, M.; Grace, S.; Hall, T.; Haynam, C.; Heestand, G.; Henesian, M.; Hermann, M.; Hermes, G.; Huber, S.; Jancaitis, K.; Johnson, S.; Kauffman, B.; Kelleher, T.; Kohut, T.; Koniges, A. E.; Labiak, T.; Latray, D.; Lee, A.; Lund, D.; Mahavandi, S.; Manes, K. R.; Marshall, C.; McBride, J.; McCarville, T.; McGrew, L.; Menapace, J.; Mertens, E.; Munro, D.; Murray, J.; Neumann, J.; Newton, M.; Opsahl, P.; Padilla, E.; Parham, T.; Parrish, G.; Petty, C.; Polk, M.; Powell, C.; Reinbachs, I.; Rinnert, R.; Riordan, B.; Ross, G.; Robert, V.; Tobin, M.; Sailors, S.; Saunders, R.; Schmitt, M.; Shaw, M.; Singh, M.; Spaeth, M.; Stephens, A.; Tietbohl, G.; Tuck, J.; van Wonterghem, B.; Vidal, R.; Wegner, P.; Whitman, P.; Williams, K.; Winward, K.; Work, K.; Wallace, R.; Nobile, A.; Bono, M.; Day, B.; Elliott, J.; Hatch, D.; Louis, H.; Manzenares, R.; O'Brien, D.; Papin, P.; Pierce, T.; Rivera, G.; Ruppe, J.; Sandoval, D.; Schmidt, D.; Valdez, L.; Zapata, K.; MacGowan, B.; Eckart, M.; Hsing, W.; Springer, P.; Hammel, B.; Moses, E.; Miller, G.

    2006-06-01

    A first set of shock propagation, laser-plasma interaction, hohlraum energetics and hydrodynamic experiments have been performed using the first 4 beams of the National Ignition Facility (NIF), in support of indirect drive Inertial Confinement Fusion (ICF) and High Energy Density Physics.

  4. Optimization of the process of plasma ignition of coal

    Energy Technology Data Exchange (ETDEWEB)

    Peregudov, V.S. [Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2009-04-15

    Results are given of experimental and theoretical investigations of plasma ignition of coal as a result of its thermochemical preparation in application to the processes of firing up a boiler and stabilizing the flame combustion. The experimental test bed with a commercial-scale burner is used for determining the conditions of plasma ignition of low-reactivity high-ash anthracite depending on the concentration of coal in the air mixture and velocity of the latter. The calculations produce an equation (important from the standpoint of practical applications) for determining the energy expenditure for plasma ignition of coal depending on the basic process parameters. The tests reveal the difficulties arising in firing up a boiler with direct delivery of pulverized coal from the mill to furnace. A scheme is suggested, which enables one to reduce the energy expenditure for ignition of coal and improve the reliability of the process of firing up such a boiler. Results are given of calculation of plasma thermochemical preparation of coal under conditions of lower concentration of oxygen in the air mixture.

  5. Real fuel effects on flame extinction and re-ignition

    Science.gov (United States)

    Zhao, Xinyu; Wu, Bifen; Xu, Chao; Lu, Tianfeng; Chen, Jacqueline H.

    2016-11-01

    Flame-vortex interactions have significant implications in studying combustion in practical aeronautical engines, and can be used to facilitate the model development in capturing local extinction and re-ignition. To study the interactions between the complex fuel and the intense turbulence that are commonly encountered in engines, direct numerical simulations of the interactions between a flame and a vortex pair are carried out using a recently-developed 24-species reduced chemistry for n-dodecane. Both non-premixed and premixed flames with different initial and inlet thermochemical conditions are studied. Parametric studies of different vortex strengths and orientations are carried out to induce maximum local extinction and re-ignition. Chemical-explosive-mode-analysis based flame diagnostic tools are used to identify different modes of combustion, including auto-ignition and extinction. Results obtained from the reduced chemistry are compared with those obtained from one-step chemistry to quantify the effect of fuel pyrolysis on the extinction limit. Effects of flame curvature, heat loss and unsteadiness on flame extinction are also explored. Finally, the validity of current turbulent combustion models to capture the local extinction and re-ignition will be discussed.

  6. Electric ignition and airless kindle for underfeed stokers

    Energy Technology Data Exchange (ETDEWEB)

    Crowther, M.E. [CRE Group Ltd., Stoke Orchard (United Kingdom)

    1996-02-01

    The leaflet describes a project carried out to assess the effectiveness and reliability of two methods of reducing the amount of coal used for kindling on boilers fitted with underfeed stokers. Many coal-fired boilers use underfeed stokers to deliver their fuel. When heat is not required, the stoker is put into standby `kindle` mode, and the fire kept alight by the periodic delivery of small amounts of coal and air. CRE Group Ltd., assessed two techniques for reducing the fuel used for kindling: electric ignition and airless kindle. Electric ignition eliminates entirely the need for kindling by automatically re-igniting the coal in the stoker retort using a hot air jet. CRE Group`s development work aimed to overcome earlier design problems and improve cost-effectiveness and reliability. Airless kindle reduces the size and frequency of coal feed in kindle mode. Although it does not entirely eliminate the use of kindle, it saves almost as much fuel for a lower capital outlay and minimal maintenance costs. This option has proved so attractive to the host organisations (Derbyshire Country Council, Nottinghamshire Country Council and Haven Nurseries) that the boiler used for trials for the electric ignition system has now been converted to airless kindle. 3 figs., 4 photos.

  7. Utilization of Alcohol Fuel in Spark Ignition and Diesel Engines.

    Science.gov (United States)

    Berndt, Don; Stengel, Ron

    These five units comprise a course intended to prepare and train students to conduct alcohol fuel utilization seminars in spark ignition and diesel engines. Introductory materials include objectives and a list of instructor requirements. The first four units cover these topics: ethanol as an alternative fuel (technical and economic advantages,…

  8. Theory of Fast Electron Transport for Fast Ignition

    CERN Document Server

    Robinson, A P L; Davies, J R; Gremillet, L; Honrubia, J J; Johzaki, T; Kingham, R J; Sherlock, M; Solodov, A A

    2013-01-01

    Fast Ignition Inertial Confinement Fusion is a variant of inertial fusion in which DT fuel is first compressed to high density and then ignited by a relativistic electron beam generated by a fast (< 20 ps) ultra-intense laser pulse, which is usually brought in to the dense plasma via the inclusion of a re-entrant cone. The transport of this beam from the cone apex into the dense fuel is a critical part of this scheme, as it can strongly influence the overall energetics. Here we review progress in the theory and numerical simulation of fast electron transport in the context of Fast Ignition. Important aspects of the basic plasma physics, descriptions of the numerical methods used, a review of ignition-scale simulations, and a survey of schemes for controlling the propagation of fast electrons are included. Considerable progress has taken place in this area, but the development of a robust, high-gain FI `point design' is still an ongoing challenge.

  9. Laser diode ignition characteristics of Zirconium Potassium Perchlorate (ZPP)

    Science.gov (United States)

    Callaghan, Jerry D.; Tindol, Scot

    1993-01-01

    Hi-Shear Technology, Corp., (HSTC) has designed and built a Laser equivalent NASA Standard Initiator (LNSI). Langlie tests with a laser diode output initiating ZPP were conducted as a part of this effort. The test parameters include time to first pressure, laser power density requirements, and ignition time. The data from these laser tests on ZPP are presented.

  10. Antiutopiskie romāni pusaudžiem „Citādie”, „Delīrijs”, „Devējs”

    OpenAIRE

    Korčevska, Jūlija

    2015-01-01

    Šis pētījums ir veltīts antiutopiskās pusaudžu literatūras analīzei V. Rotas grāmatā „Citādie”, L. Oliveras romānā „Delīrijs” un L. Lorijas darbā „Devējs”. Darba teorētisko daļu veido informācija par pusaudžiem domāto literatūru utopiskās un antiutopiskās literatūras žanru attīstību. Praktiskā daļa veltīta antiutopijas pazīmju analīzei pusaudžiem paredzētajās grāmatās „Citādie”, „Delīrijs” un „Devējs”. Pētījumā izmantota kvalitatīvā pētījumu metode, kas sevī ietver saistīto teoriju izpēti un ...

  11. Railplug Ignition System for Enhanced Engine Performance and Reduced Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    DK Ezekoye; Matt Hall; Ron Matthews

    2005-08-01

    This Final Technical Report discusses the progress that was made on the experimental and numerical tasks over the duration of this project. The primary objectives of the project were to (1) develop an improved understanding of the spark ignition process, and (2) develop the railplug as an improved ignitor for large bore stationary natural gas engines. We performed fundamental experiments on the physical processes occurring during spark ignition and used the results from these experiments to aid our development of the most complete model of the spark ignition process ever devised. The elements in this model include (1) the dynamic response of the ignition circuit, (2) a chemical kinetics mechanism that is suitable for the reactions that occur in the plasma, (3) conventional flame propagation kinetics, and (4) a multi-dimensional formulation so that bulk flow through the spark gap can be incorporated. This model (i.e., a Fortran code that can be used as a subroutine within an engine modeling code such as KIVA) can be obtained from Prof. Ron Matthews at rdmatt{at}mail.utexas.edu or Prof. DK Ezekoye at dezekoye{at}mail.utexas.edu. Fundamental experiments, engine experiments, and modeling tasks were used to help develop the railplug as a new ignitor for large bore natural gas engines. As the result of these studies, we developed a railplug that could extend the Lean Stability Limit (LSL) of an engine operating at full load on natural gas from {phi} = 0.59 for operation on spark plugs down to {phi} = 0.53 using railplugs with the same delivered energy (0.7 J). However, this delivered energy would rapidly wear out the spark plug. For a conventional delivered energy (<0.05 J), the LSL is {phi} = 0.63 for a spark plug. Further, using a permanent magnet to aid the plasma movement, the LSL was extended to {phi} = 0.54 for a railplug with a delivered energy of only 0.15 J/shot, a typical discharge energy for commercial capacitive discharge ignition systems. Here, it should be

  12. Determining Fire Dates and Locating Ignition Points With Satellite Data

    Directory of Open Access Journals (Sweden)

    Akli Benali

    2016-04-01

    Full Text Available Each wildfire has its own “history”, burns under specific conditions and leads to unique environmental impacts. Information on where and when it has started and its duration is important to improve understanding on the dynamics of individual wildfires. This information is typically included in fire databases that are known to have: (i multiple error sources; (ii limited spatial coverage and/or time span, and; (iii often unknown accuracy and uncertainty. Satellite data have a large potential to reduce such limitations. We used active fire data from the MODerate Resolution Imaging Spectroradiometer (MODIS to estimate fire start/end dates and ignition location(s for large wildfires that occurred in Alaska, Portugal, Greece, California and southeastern Australia. We assessed the agreement between satellite-derived estimates and data from fire databases, and determined the associated uncertainty. Fire dates and ignition location(s were estimated for circa 76% of the total burnt area extent for the five study regions. The ability to estimate fire dates and ignitions from satellite data increased with fire size. The agreement between reported and estimated fire dates was very good for start dates (Model efficiency index, MEF = 0.91 and reasonable for end dates (MEF = 0.73. The spatio-temporal agreement between reported and satellite-derived wildfire ignitions showed temporal lags and distances within 12 h and 2 km, respectively. Uncertainties associated with ignition estimates were generally larger than the disagreements with data reported in fire databases. Our results show how satellite data can contribute to improve information regarding dates and ignitions of large wildfires. This contribution can be particularly relevant in regions with scarce fire information, while in well-documented areas it can be used to complement, potentially detect, and correct inconsistencies in existing fire databases. Using data from other existing and/or upcoming

  13. The Comparison of Hydrotreated Vegetable Oils With Respect to Petroleum Derived Fuels and the Effects of Transient Plasma Ignition in a Compression-Ignition Engine

    Science.gov (United States)

    2012-09-01

    HYDROTREATED VEGETABLE OILS WITH RESPECT TO PETROLEUM DERIVED FUELS AND THE EFFECTS OF TRANSIENT PLASMA IGNITION IN A COMPRESSION-IGNITION ENGINE by...SUBTITLE The Comparison of Hydrotreated Vegetable Oils With respect to Petroleum Derived Fuels and the Effects of Transient Plasma Ignition in a... Hydrotreated Renewable Diesel, algae, and benchmarked against F-76 and Diesel #2 fuels as well as Hydrotreated Renewable Jet, camelina, benchmarked

  14. Are Published Minimum Vapor Phase Spark Ignition Energy Data Valid?

    Energy Technology Data Exchange (ETDEWEB)

    Staggs, K J; Alvares, N J; Greenwood, D W

    2001-11-21

    The use of sprayed flammable fluids as solvents in dissolution and cleaning processes demand detailed understanding of ignition and fire hazards associated with these applications. When it is not feasible to inert the atmosphere in which the spraying process takes place, then elimination of all possible ignition sources must be done. If operators are involved in the process, the potential for human static build-up and ultimate discharge is finite, and it is nearly impossible to eliminate. The specific application discussed in this paper involved the use of heated Dimethyl Sulfoxide (DMSO) to dissolve high explosives (HE). Search for properties of DMSO yielded data on flammability limits and flash point, but there was no published information pertaining to the minimum energy for electrical arc ignition. Due to the sensitivity of this procedure, The Hazards Control Department of Lawrence Livermore National Laboratory (LLNL) was tasked to determine the minimum ignition energy of DMSO aerosol and vapor an experimental investigation was thus initiated. Because there were no electrical sources in spray chamber, Human Electro-Static Discharge (HESD) was the only potential ignition source. Consequently, the electrostatic generators required for this investigation were designed to produce electrostatic arcs with the defined voltage and current pulse characteristics consistent with simulated human capacitance. Diagnostic procedures required to insure these characteristics involve specific data gathering techniques where the voltage and current sensors are in close proximity to the electrodes, thus defining the arc energy directly between the electrodes. The intriguing finding derived from this procedure is how small these measured values are relative to the arc energy as defined by the capacitance and the voltage measure at the capacitor terminals. The suggested reason for this difference is that the standard procedure for determining arc energy from the relation; E = 1/2CV

  15. Localized microwave pulsed plasmas for ignition and flame front enhancement

    Science.gov (United States)

    Michael, James Bennett

    Modern combustor technologies require the ability to match operational parameters to rapidly changing demands. Challenges include variable power output requirements, variations in air and fuel streams, the requirement for rapid and well-controlled ignition, and the need for reliability at low fuel mixture fractions. Work on subcritical microwave coupling to flames and to weakly ionized laser-generated plasmas has been undertaken to investigate the potential for pulsed microwaves to allow rapid combustion control, volumetric ignition, and leaner combustion. Two strategies are investigated. First, subcritical microwaves are coupled to femtosecond laser-generated ionization to ignite methane/air mixtures in a quasi-volumetric fashion. Total energy levels are comparable to the total minimum ignition energies for laser and spark discharges, but the combined strategy allows a 90 percent reduction in the required laser energy. In addition, well-defined multi-dimensional ignition patterns are designated with multiple laser passes. Second, microwave pulse coupling to laminar flame fronts is achieved through interaction with chemiionization-produced electrons in the reaction zone. This energy deposition remains well-localized for a single microwave pulse, resulting in rapid temperature rises of greater than 200 K and maintaining flame propagation in extremely lean methane/air mixtures. The lean flammability limit in methane/air mixtures with microwave coupling has been decreased from an equivalence ratio 0.6 to 0.3. Additionally, a diagnostic technique for laser tagging of nitrogen for velocity measurements is presented. The femtosecond laser electronic excitation tagging (FLEET) technique utilizes a 120 fs laser to dissociate nitrogen along a laser line. The relatively long-lived emission from recombining nitrogen atoms is imaged with a delayed and fast-gated camera to measure instantaneous velocities. The emission strength and lifetime in air and pure nitrogen allow

  16. Safety Implementation of Hydrogen Igniters and Recombiners for Nuclear Power Plant Severe Accident Management

    Institute of Scientific and Technical Information of China (English)

    XIAO Jianjun; ZHOU Zhiwei; JING Xingqing

    2006-01-01

    Hydrogen combustion in a nuclear power plant containment building may threaten the integrity of the containment. Hydrogen recombiners and igniters are two methods to reduce hydrogen levels in containment buildings during severe accidents. The purpose of this paper is to evaluate the safety implementation of hydrogen igniters and recombiners. This paper analyzes the risk of deliberate hydrogen ignition and investigates three mitigation measures using igniters only, hydrogen recombiners only or a combination of recombiners and igniters. The results indicate that steam can effectively control the hydrogen flame acceleration and the deflagration-to-detonation transition.

  17. Experimental and Numerical Study on Effect of Sample Orientation on Auto-Ignition and Piloted Ignition of Poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Fei Peng

    2015-07-01

    Full Text Available In this work, the effect of seven different sample orientations from 0° to 90° on pilot and non-pilot ignition of PMMA (poly(methyl methacrylate exposed to radiation has been studied with experimental and numerical methods. Some new and significant conclusions are drawn from the study, including a U-shape curve of ignition time and critical mass flux as sample angle increases for pilot ignition conditions. However, in auto-ignition, the ignition time and critical mass flux increases with sample angle α. Furthermore, a computational fluid dynamic model have been built based on the Fire Dynamics Simulator (FDS6 code to investigate the mechanisms controlling the dependence on sample orientation of the ignition of PMMA under external radiant heating. The results of theoretical analysis and modeling results indicate the decrease of total incident heat flux at sample surface plays the dominant role during the ignition processes of auto-ignition, but the volatiles gas flow has greater influence for piloted ignition conditions.

  18. Der Global Compact und der Schutz der Menschenrechte

    OpenAIRE

    Hamm, Brigitte I.

    2011-01-01

    Inhalt: - I. Einleitung - II. Was ist der Global Compact? - III. Wie funktioniert der Global Compact? - IV. Der Global Compact will kein Verhaltenskodex sein. - V. Der Global Compact als Bestandteil von „global governance“ - VI. Der Global Compact und der Schutz der Menschenrechte - VII. Ausschau - Literatur - Teilnehmer des Global Compact

  19. Porewater chemistry in compacted bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Muurinen, A.; Lehikoinen, J. [VTT Chemical Technology, Espoo (Finland)

    1999-03-01

    In this study, the porewater chemistry in compacted bentonite, considered as an engineered barrier in the repository of spent fuel, has been studied in interaction experiments. Many parameters, like the composition and density of bentonite, composition of the solution, bentonite-to-water ratio (B/W), surrounding conditions and experimental time have been varied in the experiments. At the end of the interaction the equilibrating solution, the porewaters squeezed out of the bentonite samples, and bentonites themselves were analyzed to give information for the interpretation and modelling of the interaction. Equilibrium modelling was performed with the HYDRAQL/CE computer code 33 refs.

  20. Compact Hermitian Young Projection Operators

    CERN Document Server

    Alcock-Zeilinger, Judith

    2016-01-01

    In this paper, we describe a compact and practical algorithm to construct Hermitian Young projection operators for irreducible representations of the special unitary group SU(N), and discuss why ordinary Young projection operators are unsuitable for physics applications. The proof of this construction algorithm uses the iterative method described by Keppeler and Sj\\"odahl. We further show that Hermitian Young projection operators share desirable properties with Young tableaux, namely a nested hierarchy when "adding a particle". We end by exhibiting the enormous advantage of the Hermitian Young projection operators constructed in this paper over those given by Keppeler and Sj\\"odahl.