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Sample records for accelerator-driven systems ads

  1. High Power Cyclotrons for Accelerator Driven System (ADS)

    NASA Astrophysics Data System (ADS)

    Calabretta, Luciano

    2012-03-01

    We present an accelerator module based on a injector cyclotron and a Superconducting Ring Cyclotron (SRC) able to accelerate H2+ molecules. H2+ molecules are extracted from the SRC stripping the binding electron by a thin carbon foil. The SRC will be able to deliver proton beam with maximum energy of 800 MeV and a maximum power of 8 MW. This module is forecasted for the DAEdALUS (Decay At rest Experiment for δcp At Laboratory for Underground Science) experiment, which is a neutrino experiment proposed by groups of MIT and Columbia University. Extensive beam dynamics studies have been carrying out in the last two years and proved the feasibility of the design. The use of H2+ molecules beam has three main advantages: 1) it reduces the space charge effects, 2) because of stripping extraction, it simplifies the extraction process w.r.t. single turn extraction and 3) we can extract more than one beam out of one SRC. A suitable upgraded version of the cyclotron module able to deliver up to 10MW beam is proposed to drive ADS. The accelerator system which is presented, consists of having three accelerators modules. Each SRC is equipped with two extraction systems delivering two beams each one with a power up to 5 MW. Each accelerator module, feeds both the two reactors at the same time. The three accelerators modules assure to maintain continuity in functioning of the two reactors. In normal operation, all the three accelerators module will deliver 6.6 MW each one, just in case one of the three accelerator module will be off, due to a fault or maintenance, the other two modules are pushed at maximum power of 10 MW. The superconducting magnetic sector of the SRC, as well as the normal conducting sector of the injector cyclotron, is calculated with the TOSCA module of OPERA3D. Here the main features of the injector cyclotron, of the SRC and the beam dynamic along the cyclotrons are presented.

  2. YALINA facility a sub-critical Accelerator- Driven System (ADS) for nuclear energy research facility description and an overview of the research program (1997-2008).

    SciTech Connect

    Gohar, Y.; Smith, D. L.; Nuclear Engineering Division

    2010-04-28

    The YALINA facility is a zero-power, sub-critical assembly driven by a conventional neutron generator. It was conceived, constructed, and put into operation at the Radiation Physics and Chemistry Problems Institute of the National Academy of Sciences of Belarus located in Minsk-Sosny, Belarus. This facility was conceived for the purpose of investigating the static and dynamic neutronics properties of accelerator driven sub-critical systems, and to serve as a neutron source for investigating the properties of nuclear reactions, in particular transmutation reactions involving minor-actinide nuclei. This report provides a detailed description of this facility and documents the progress of research carried out there during a period of approximately a decade since the facility was conceived and built until the end of 2008. During its history of development and operation to date (1997-2008), the YALINA facility has hosted several foreign groups that worked with the resident staff as collaborators. The participation of Argonne National Laboratory in the YALINA research programs commenced in 2005. For obvious reasons, special emphasis is placed in this report on the work at YALINA facility that has involved Argonne's participation. Attention is given here to the experimental program at YALINA facility as well as to analytical investigations aimed at validating codes and computational procedures and at providing a better understanding of the physics and operational behavior of the YALINA facility in particular, and ADS systems in general, during the period 1997-2008.

  3. Nuclear data needs for accelerator-driven transmutation systems

    SciTech Connect

    Arthur, E.D.; Wilson, W.B.; Young, P.G.

    1994-07-01

    The possibilities of several new technologies based on use of intense, medium-energy proton accelerators are being investigated at Los Alamos National Laboratory. The potential new areas include destruction of long-lived components of nuclear waste, plutonium burning, energy production, and production of tritium. The design, assessment, and safety analysis of potential facilities involves the understanding of complex combinations of nuclear processes, which in turn places new requirements on nuclear data that transcend the traditional needs of the fission and fusion reactor communities. In this paper an assessment of the nuclear data needs for systems currently being considered in the Los Alamos Accelerator-Driven Transmutation Technologies program is given.

  4. Inherent Safety of Fuels for Accelerator-Driven Systems

    SciTech Connect

    Eriksson, M.; Wallenius, J.; Jolkkonen, M.; Cahalan, J.E

    2005-09-15

    Transient safety characteristics of accelerator-driven systems using advanced minor actinide fuels have been investigated. Results for a molybdenum-based Ceramic-Metal (CerMet) fuel, a magnesia-based Ceramic-Ceramic fuel, and a zirconium-nitride-based fuel are reported. The focus is on the inherent safety aspects of core design. Accident analyses are carried out for the response to unprotected loss-of-flow and accelerator beam-overpower transients and coolant voiding scenarios. An attempt is made to establish basic design limits for the fuel and cladding. Maximum temperatures during transients are determined and compared with design limits. Reactivity effects associated with coolant void, fuel and structural expansion, and cladding relocation are investigated. Design studies encompass variations in lattice pitch and pin diameter. Critical mass studies are performed. The studies indicate favorable inherent safety features of the CerMet fuel. Major consideration is given to the potential threat of coolant voiding in accelerator-driven design proposals. Results for a transient test case study of a postulated steam generator tube rupture event leading to extensive coolant voiding are presented. The study underlines the importance of having a low coolant void reactivity value in a lead-bismuth system despite the high boiling temperature of the coolant. It was found that the power rise following a voiding transient increases dramatically near the critical state. The studies suggest that a reactivity margin of a few dollars in the voided state is sufficient to permit significant reactivity insertions.

  5. Radiological Hazard of Spallation Products in Accelerator-Driven System

    SciTech Connect

    Saito, M.; Stankovskii, A.; Artisyuk, V.; Korovin, Yu.; Shmelev, A.; Titarenko, Yu.

    2002-09-15

    The central issue underlying this paper is related to elucidating the hazard of radioactive spallation products that might be an important factor affecting the design option of accelerator-driven systems (ADSs). Hazard analysis based on the concept of Annual Limit on Intake identifies alpha-emitting isotopes of rare earths (REs) (dysprosium, gadolinium, and samarium) as the dominant contributors to the overall toxicity of traditional (W, Pb, Pb-Bi) targets. The matter is addressed from several points of view: code validation to simulate their yields, choice of material for the neutron producing targets, and challenging the beam type. The paper quantitatively determines the domain in which the toxicity of REs exceeds that of polonium activation products broadly discussed now in connection with advertising lead-bismuth technology for the needs of ADSs.

  6. Investigation of Lead Target Nuclei Used on Accelerator-Driven Systems for Tritium Production

    NASA Astrophysics Data System (ADS)

    Tel, E.; Aydin, A.

    2012-02-01

    High-current proton accelerators are being researched at Los Alamos National Laboratory and other laboratories for accelerator production of tritium, transmuting long-lived radioactive waste into shorter-lived products, converting excess plutonium, and producing energy. These technologies make use of spallation neutrons produced in ( p,xn) and ( n,xn) nuclear reactions on high-Z targets. Through ( p,xn) and ( n,xn) nuclear reactions, neutrons are produced and are moderated by heavy water. These moderated neutrons are subsequently captured on 3He to produce tritium via the ( n,p) reaction. Tritium self-sufficiency must be maintained for a commercial fusion power plant. Rubbia succeeded in a proposal of a full scale demonstration plant of the Energy Amplifier. This plant is to be known the accelerator-driven system (ADS). The ADS can be used for production of neutrons in spallation neutron source and they can act as an intense neutron source in accelerator-driven subcritical reactors, capable of incinerating nuclear waste and of producing energy. Thorium and Uranium are nuclear fuels and Lead, Bismuth, Tungsten are the target nuclei in these reactor systems. The spallation targets can be Pb, Bi, W, etc. isotopes and these target material can be liquid or solid. Naturally Lead includes the 204Pb (%1.42), 206Pb (%24.1), 207Pb (%22.1) and 208Pb (%52.3) isotopes. The design of ADS systems and also a fusion-fission hybrid reactor systems require the knowledge of a wide range of better data. In this study, by using Hartree-Fock method with an effective nucleon-nucleon Skyrme interactions rms nuclear charge radii, rms nuclear mass radii, rms nuclear proton, neutron radii and neutron skin thickness were calculated for the 204, 206, 208Pb isotopes . The calculated results have been compared with those of the compiled experimental and theoretical values of other studies.

  7. Disposition of nuclear waste using subcritical accelerator-driven systems

    SciTech Connect

    Venneri, F.; Li, N.; Williamson, M.; Houts, M.; Lawrence, G.

    1998-12-31

    Spent fuel from nuclear power plants contains large quantities of Pu, other actinides, and fission products (FP). This creates challenges for permanent disposal because of the long half-lives of some isotopes and the potential for diversion of the fissile material. Two issues of concern for the US repository concept are: (1) long-term radiological risk peaking tens-of-thousands of years in the future; and (2) short-term thermal loading (decay heat) that limits capacity. An accelerator-driven neutron source can destroy actinides through fission, and can convert long-lived fission products to shorter-lived or stable isotopes. Studies over the past decade have established that accelerator transmutation of waste (ATW) can have a major beneficial impact on the nuclear waste problem. Specifically, the ATW concept the authors are evaluating: (1) destroys over 99.9% of the actinides; (2) destroys over 99.9% of the Tc and I; (3) separates Sr-90 and Cs-137; (4) separates uranium from the spent fuel; (5) produces electric power.

  8. Shielding Assessment of the MYRRHA Accelerator-Driven System Using the MCNP Code

    NASA Astrophysics Data System (ADS)

    Coeck, M.; Aoust, Th.; Vermeersch, F.; Abderrahim, A.

    The MYRRHA project includes the design and the development of an accelerator driven system (ADS) aimed at providing protons and neutrons for various R&D applications. With regard to the safety aspects, the assessment of the shielding and of the dose rates around the installation is an important task. In a first approach standard semi-empirical equations and attenuation factors found in the literature were applied. A more detailed determination of the neutron flux around the reactor is made here by Monte Carlo simulation with the code MCNP4B. The results of the shielding assessment give an estimate of the neutron flux at several positions around the core vessel and along the beam tube. Dose rates will be determined by applying the ICRP74 conversion factor.

  9. Myrrha, a Multipurpose Accelerator Driven System for R&d - Present Status

    NASA Astrophysics Data System (ADS)

    D'Hondt, P.; Aït Abderrahim, H.; Kupschus, P.; Benoit, P.; Malambu, E.; Sobolev, V.; Aoust, T.; van Tichelen, K.; Arien, B.; Vermeersch, F.; de Bruyn, D.; Maes, D.; Haeck, W.; Jongen, Y.; Vandeplassche, D.

    2004-02-01

    Since 1998, SCK•CEN in partnership with IBA s.a., is designing a multipurpose ADS for R&D applications -MYRRHA - and is conducting an associated R&D support programme. MYRRHA is an Accelerator Driven System (ADS) under development at Mol in Belgium and aiming to serve as a basis for the European experimental ADS to provide protons and neutrons for various R&D applications. It consists of a proton accelerator delivering a 350 MeV*5 mA proton beam to a liquid Pb-Bi spallation target that in turn couples to a Pb-Bi cooled, subcritical fast core. In a first stage, the project focuses mainly on demonstration of the ADS concept, safety research on sub-critical systems and nuclear waste transmutation studies. In a later stage, the device will also be dedicated to research on structural materials, nuclear fuel, liquid metal technology and associated aspects and on sub-critical reactor physics. Subsequently, it will be used for research on applications such as radioisotope production. The MYRRHA system is expected to become a major research infrastructure for the European partners involved in the P&T and ADS Demo development.

  10. MYRRHA: A multipurpose accelerator driven system for research & development

    NASA Astrophysics Data System (ADS)

    Abderrahim, H. Aı̈t; Kupschus, P.; Malambu, E.; Benoit, Ph; Van Tichelen, K.; Arien, B.; Vermeersch, F.; D'hondt, P.; Jongen, Y.; Ternier, S.; Vandeplassche, D.

    2001-05-01

    SCK·CEN, the Belgian Nuclear Research Centre, in partnership with IBA s.a., Ion Beam Applications, is designing an ADS prototype, MYRRHA, and is conducting an associated R&D programme. The project focuses primarily on research on structural materials, nuclear fuel, liquid metals and associated aspects, on subcritical reactor physics and subsequently on applications such as nuclear waste transmutation, radioisotope production and safety research on sub-critical systems. The MYRRHA system is intended to be a multipurpose R&D facility and is expected to become a new major research infrastructure for the European partners presently involved in the ADS Demo development. Ion Beam Applications is performing the accelerator development. Currently the preliminary conceptual design of the MYRRHA system is under way and an intensive R&D programme is assessing the points of greatest risk in the present design. This work will define the final choice of characteristics of the facility. In this paper, we will report on the status of the pre-design study as of June 2000 as well as on the methods and results of the R&D programme.

  11. Detector positioning for the initial subcriticality level determination in accelerator-driven systems

    SciTech Connect

    Uyttenhove, W.; Van Den Eynde, G.; Baeten, P.; Kochetkov, A.; Vittiglio, G.; Wagemans, J.; Lathouwers, D.; Kloosterman, J. L.; Van Der Hagen, T. J. H. H.; Wols, F.; Billebaud, A.; Chabod, S.; Thybault, H. E.

    2012-07-01

    Within the GUINEVERE project (Generation of Uninterrupted Intense Neutrons at the lead Venus Reactor) carried out at SCK-CEN in Mol, the continuous deuteron accelerator GENEPI-3C was coupled to the VENUS-F fast simulated lead-cooled reactor. Today the FREYA project (Fast Reactor Experiments for hYbrid Applications) is ongoing to study the neutronic behavior of this Accelerator Driven System (ADS) during different phases of operation. In particular the set-up of a monitoring system for the subcriticality of an ADS is envisaged to guarantee safe operation of the installation. The methodology for subcriticality monitoring in ADS takes into account the determination of the initial subcriticality level, the monitoring of reactivity variations, and interim cross-checking. At start-up, the Pulsed Neutron Source (PNS) technique is envisaged to determine the initial subcriticality level. Thanks to its reference critical state, the PNS technique can be validated on the VENUS-F core. A detector positioning methodology for the PNS technique is set up in this paper for the subcritical VENUS-F core, based on the reduction of higher harmonics in a static evaluation of the Sjoestrand area method. A first case study is provided on the VENUS-F core. This method can be generalised in order to create general rules for detector positions and types for full-scale ADS. (authors)

  12. Physics design of an accelerator for an accelerator-driven subcritical system

    NASA Astrophysics Data System (ADS)

    Li, Zhihui; Cheng, Peng; Geng, Huiping; Guo, Zhen; He, Yuan; Meng, Cai; Ouyang, Huafu; Pei, Shilun; Sun, Biao; Sun, Jilei; Tang, Jingyu; Yan, Fang; Yang, Yao; Zhang, Chuang; Yang, Zheng

    2013-08-01

    An accelerator-driven subcritical system (ADS) program was launched in China in 2011, which aims to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power in multiple phases lasting about 20 years. The driver linac is defined to be 1.5 GeV in energy, 10 mA in current and in cw operation mode. To meet the extremely high reliability and availability, the linac is designed with much installed margin and fault tolerance, including hot-spare injectors and local compensation method for key element failures. The accelerator complex consists of two parallel 10-MeV injectors, a joint medium-energy beam transport line, a main linac, and a high-energy beam transport line. The superconducting acceleration structures are employed except for the radio frequency quadrupole accelerators (RFQs) which are at room temperature. The general design considerations and the beam dynamics design of the driver linac complex are presented here.

  13. Simulator for an Accelerator-Driven Subcritical Fissile Solution System

    SciTech Connect

    Klein, Steven Karl; Day, Christy M.; Determan, John C.

    2015-09-14

    LANL has developed a process to generate a progressive family of system models for a fissile solution system. This family includes a dynamic system simulation comprised of coupled nonlinear differential equations describing the time evolution of the system. Neutron kinetics, radiolytic gas generation and transport, and core thermal hydraulics are included in the DSS. Extensions to explicit operation of cooling loops and radiolytic gas handling are embedded in these systems as is a stability model. The DSS may then be converted to an implementation in Visual Studio to provide a design team the ability to rapidly estimate system performance impacts from a variety of design decisions. This provides a method to assist in optimization of the system design. Once design has been generated in some detail the C++ version of the system model may then be implemented in a LabVIEW user interface to evaluate operator controls and instrumentation and operator recognition and response to off-normal events. Taken as a set of system models the DSS, Visual Studio, and LabVIEW progression provides a comprehensive set of design support tools.

  14. Disposition of Nuclear Waste Using Subcritical Accelerator-Driven Systems

    SciTech Connect

    Doolen, G.D.; Venneri, F.; Li, N.; Williamson, M.A.; Houts, M.; Lawrence, G.

    1998-06-27

    ATW destroys virtually all the plutonium and higher actinides without reprocessing the spent fuel in a way that could lead to weapons material diversion. An ATW facility consists of three major elements: (1) a high-power proton linear accelerator; (2) a pyrochemical spent fuel treatment i waste cleanup system; (3) a liquid lead-bismuth cooled burner that produces and utilizes an intense source-driven neutron flux for transmutation in a heterogeneous (solid fuel) core. The concept is the result of many years of development at LANL as well as other major international research centers. Once demonstrated and developed, ATW could be an essential part of a global non-proliferation strategy for countries that could build up large quantities of plutonium from their commercial reactor waste. ATW technology, initially proposed in the US, has received wide and rapidly increasing attention abroad, especially in Europe and the Far East with major programs now being planned, organized and tided. Substantial convergence presently exists on the technology choices among the programs, opening the possibility of a strong and effective international collaboration on the phased development of the ATW technology.

  15. Temperature Profile of the Solution Vessel of an Accelerator-Driven Subcritical Fissile Solution System

    SciTech Connect

    Klein, Steven Karl; Determan, John C.

    2015-09-14

    Dynamic System Simulation (DSS) models of fissile solution systems have been developed and verified against a variety of historical configurations. DSS techniques have been applied specifically to subcritical accelerator-driven systems using fissile solution fuels of uranium. Initial DSS models were developed in DESIRE, a specialized simulation scripting language. In order to tailor the DSS models to specifically meet needs of system designers they were converted to a Visual Studio implementation, and one of these subsequently to National Instrument’s LabVIEW for human factors engineering and operator training. Specific operational characteristics of subcritical accelerator-driven systems have been examined using a DSS model tailored to this particular class using fissile fuel.

  16. Optimisation of composite metallic fuel for minor actinide transmutation in an accelerator-driven system

    NASA Astrophysics Data System (ADS)

    Uyttenhove, W.; Sobolev, V.; Maschek, W.

    2011-09-01

    A potential option for neutralization of minor actinides (MA) accumulated in spent nuclear fuel of light water reactors (LWRs) is their transmutation in dedicated accelerator-driven systems (ADS). A promising fuel candidate dedicated to MA transmutation is a CERMET composite with Mo metal matrix and (Pu, Np, Am, Cm)O 2-x fuel particles. Results of optimisation studies of the CERMET fuel targeting to increasing the MA transmutation efficiency of the EFIT (European Facility for Industrial Transmutation) core are presented. In the adopted strategy of MA burning the plutonium (Pu) balance of the core is minimized, allowing a reduction in the reactivity swing and the peak power form-factor deviation and an extension of the cycle duration. The MA/Pu ratio is used as a variable for the fuel optimisation studies. The efficiency of MA transmutation is close to the foreseen theoretical value of 42 kg TW -1 h -1 when level of Pu in the actinide mixture is about 40 wt.%. The obtained results are compared with the reference case of the EFIT core loaded with the composite CERCER fuel, where fuel particles are incorporated in a ceramic magnesia matrix. The results of this study offer additional information for the EFIT fuel selection.

  17. Pre-design of MYRRHA, A Multipurpose Accelerator Driven System for Research and Development

    SciTech Connect

    D'hondt, P.; Abderrahim, H. Aiet; Kupschus, P.; Malambu, E.; Aoust, Th.; Benoit, Ph.; Sobolev, V.; Tichelen, K. van; Arien, B.; Vermeersch, F.; Jongen, Y.; Ternier, S.; Vandeplassche, D.

    2003-08-26

    One of the main SCKCEN research facility, namely BR2, is nowadays arriving at an age of 40 years just like the major materials testing reactors (MTR) in the world and in Europe (i.e. BR2 (B-Mol), HFR (EU-Petten), OSIRIS (F-Saclay), R2 (S-Studsvik)). The MYRRHA facility in planning has been conceived as potentially replacing BR2 and to be a fast spectrum facility complementary to the thermal spectrum RJH (Reacteur Jules Horowitz) facility, in planning in France. This situation would give Europe a full research capability in terms of nuclear R and D. Furthermore, the disposal of radioactive wastes resulting from industrial nuclear energy production has still to find a fully satisfactory solution, especially in terms of environmental and social acceptability. Scientists are looking for ways to drastically reduce (by a factor of 100 or more) the radio-toxicity of the High Level Waste (HLW) to be stored in a deep geological repository. This can be achieved via burning of minor actinides (MA) and to a less extent of long-lived fission products (LLFP) in Accelerator Driven Systems. The MYRRHA project contribution will be in helping to demonstrate the ADS concept at reasonable power level and the demonstration of the technological feasibility of MA and LLFP transmutation under real conditions.

  18. Pre-design of MYRRHA, A Multipurpose Accelerator Driven System for Research and Development

    NASA Astrophysics Data System (ADS)

    D'hondt, P.; Abderrahim, H. Aït; Kupschus, P.; Malambu, E.; Aoust, Th.; Benoit, Ph.; Sobolev, V.; Van Tichelen, K.; Arien, B.; Vermeersch, F.; Jongen, Y.; Ternier, S.; Vandeplassche, D.

    2003-08-01

    One of the main SCK•CEN research facility, namely BR2, is nowadays arriving at an age of 40 years just like the major materials testing reactors (MTR) in the world and in Europe (i.e. BR2 (B-Mol), HFR (EU-Petten), OSIRIS (F-Saclay), R2 (S-Studsvik)). The MYRRHA facility in planning has been conceived as potentially replacing BR2 and to be a fast spectrum facility complementary to the thermal spectrum RJH (Réacteur Jules Horowitz) facility, in planning in France. This situation would give Europe a full research capability in terms of nuclear R&D. Furthermore, the disposal of radioactive wastes resulting from industrial nuclear energy production has still to find a fully satisfactory solution, especially in terms of environmental and social acceptability. Scientists are looking for ways to drastically reduce (by a factor of 100 or more) the radio-toxicity of the High Level Waste (HLW) to be stored in a deep geological repository. This can be achieved via burning of minor actinides (MA) and to a less extent of long-lived fission products (LLFP) in Accelerator Driven Systems. The MYRRHA project contribution will be in helping to demonstrate the ADS concept at reasonable power level and the demonstration of the technological feasibility of MA and LLFP transmutation under real conditions.

  19. Behaviour of materials for accelerator driven systems in stagnant molten lead

    NASA Astrophysics Data System (ADS)

    Benamati, Gianluca; Buttol, Patrizia; Imbeni, Valentina; Martini, Carla; Palombarini, Giuseppe

    2000-06-01

    The behaviour of a modified F82H martensitic steel (both uncoated and aluminised) and tungsten was evaluated by immersion tests in stagnant, oxygen-saturated liquid lead at 793 K under an argon atmosphere, for exposure times up to 3700 h. The F82H steel is a candidate structural material for Accelerator Driven Systems (ADS), while tungsten is potentially suitable for a beam window working immersed in liquid lead. Layers of Me 3O 4 consisting of an inner sublayer with Me=Fe and Cr and an outer chromium-free sublayer of Fe 3O 4, formed on the surface of the uncoated steel while the aluminised steel showed no significant alteration. On tungsten, a compact and adherent layer of WO 3 formed and reacted with liquid lead leading to the formation of friable Pb-W-O ternary compounds. A two-step mechanism is proposed for interactions of metals and alloys exposed to oxygen-saturated molten lead: the first step is the solid phase oxidation of the base metal; the second is the interaction between liquid lead and the oxide layer formed on the metal surface.

  20. A neutron booster for spallation sources—application to accelerator driven systems and isotope production

    NASA Astrophysics Data System (ADS)

    Galy, J.; Magill, J.; Van Dam, H.; Valko, J.

    2002-06-01

    One can design a critical system with fissile material in the form of a thin layer on the inner surface of a cylindrical neutron moderator such as graphite or beryllium. Recently, we have investigated the properties of critical and near critical systems based on the use of thin actinide layers of uranium, plutonium and americium. The thickness of the required fissile layer depends on the type of fissile material, its concentration in the layer and on the geometrical arrangement, but is typically in the μm-mm range. The resulting total mass of fissile material can be as low as 100 g. Thin fissile layers have a variety of applications in nuclear technology—for example in the design neutron amplifiers for medical applications and "fast" islands in thermal reactors for waste incineration. In the present paper, we investigate the properties of a neutron booster unit for spallation sources and isotope production. In those applications a layer of fissile material surrounds the spallation source. Such a module could be developed for spallation targets foreseen in the MYRRHA (L. Van Den Durpel, H. Aı̈t Abderrahim, P. D'hondt, G. Minsart, J.L. Bellefontaine, S. Bodart, B. Ponsard, F. Vermeersch, W. Wacquier. A prototype accelerator driven system in Belgium: the Myrrha project, Technical Committee Meeting on Feasibility and Motivation for Hybrid concepts for Nuclear Energy generation and Transmutation, Madrid, Spain, September 17-19, 1997 [1]). or MEGAPIE (M. Salvatores, G.S. Bauer, G. Heusener. The MEGAPIE initiative: executive outline and status as per November 1999, MPO-1-GB-6/0_GB, 1999 [2]) projects. With a neutron multiplication factor of the booster unit in the range 10-20 (i.e. with a keff of 0.9-0.95), considerably less powerful accelerators would be required to obtain the desired neutron flux. Instead of the powerful accelerators with proton energies of 1 GeV and currents of 10 mA foreseen for accelerator driven systems, similar neutron fluxes can be obtained

  1. Conceptual design of minor actinides burner with an accelerator-driven subcritical system.

    SciTech Connect

    Cao, Y.; Gohar, Y.

    2011-11-04

    In the environmental impact study of the Yucca Mountain nuclear waste repository, the limit of spent nuclear fuel (SNF) for disposal is assessed at 70,000 metric tons of heavy metal (MTHM), among which 63,000 MTHM are the projected SNF discharge from U.S. commercial nuclear power plants though 2011. Within the 70,000 MTHM of SNF in storage, approximately 115 tons would be minor actinides (MAs) and 585 tons would be plutonium. This study describes the conceptual design of an accelerator-driven subcritical (ADS) system intended to utilize (burn) the 115 tons of MAs. The ADS system consists of a subcritical fission blanket where the MAs fuel will be burned, a spallation neutron source to drive the fission blanket, and a radiation shield to reduce the radiation dose to an acceptable level. The spallation neutrons are generated from the interaction of a 1 GeV proton beam with a lead-bismuth eutectic (LBE) or liquid lead target. In this concept, the fission blanket consists of a liquid mobile fuel and the fuel carrier can be LBE, liquid lead, or molten salt. The actinide fuel materials are dissolved, mixed, or suspended in the liquid fuel carrier. Therefore, fresh fuel can be fed into the fission blanket to adjust its reactivity and to control system power during operation. Monte Carlo analyses were performed to determine the overall parameters of an ADS system utilizing LBE as an example. Steady-state Monte Carlo simulations were studied for three fission blanket configurations that are similar except that the loaded amount of actinide fuel in the LBE is either 5, 7, or 10% of the total volume of the blanket, respectively. The neutron multiplication factor values of the three configurations are all approximately 0.98 and the MA initial inventories are each approximately 10 tons. Monte Carlo burnup simulations using the MCB5 code were performed to analyze the performance of the three conceptual ADS systems. Preliminary burnup analysis shows that all three conceptual ADS

  2. Chemistry technology base and fuel cycle of the Los Alamos accelerator-driven transmutation system

    SciTech Connect

    Williamson, M.A.

    1997-12-01

    This paper provides a brief overview of the Los Alamos accelerator-driven transmutation system, a description of the pyrochemistry technology base and the fuel cycle for the system. The pyrochemistry technology base consists of four processes: direct oxide reduction, reductive extraction, electrorefining, and electrowinning. Each process and its utility is described. The fuel cycle is described for a liquid metal-based system with the focus being the conversion of commercial spent nuclear fuel to fuel for the transmutation system. Fission product separation and actinide recycle processes are also described.

  3. Comparison of Lead-Bismuth and Lead as Coolants for Accelerator Driven Systems

    SciTech Connect

    Bianchi, F.; Mattioda, F.; Meloni, P.

    2002-07-01

    In the framework of the Italian research program TRASCO (TRAsmutazione SCOrie, namely transmutation of radioactive wastes) and of the European research program PDS-XADS (Preliminary Design Study on an eXperimental Accelerator Driven System) the feasibility and operability of gas or liquid metal cooled accelerator driven system prototypes are currently under investigation. Initially the attention of the thermal-hydraulics group of ENEA research centre in Bologna has been focussed toward a lead-bismuth cooled subcritical system under natural or enhanced natural circulation according to the prototype design proposed. The interest in using lead as a coolant, which is characterized by a higher melting point, is explained by the need to increase the plant efficiency for the economic competitiveness, though the higher temperatures pose some technological problems. Moreover, the amount of activation products should result significantly lower. Of course the results obtained and the experience gained analysing the dynamical behaviour of the lead-bismuth cooled system cannot be directly transferred to lead cooled systems. This paper aims at presenting a preliminary comparison of lead-bismuth and lead in a simplified liquid metal cooled subcritical system, mainly from the thermal-hydraulics and system dynamics points of view. By means of the modified RELAP5 version, the dynamical behavior of a lead-bismuth or lead cooled system, which is intended to be a quite accurate representation of the Italian accelerator driven prototype XADS, has been studied. Although a more exhaustive comparison should take into account the necessarily different structural characteristics of lead-bismuth and lead cooled systems, the neutronic feedback on reactor power and also the slightly different neutronic properties of lead-bismuth and lead, the purely thermal-hydraulic analysis presented in this paper has shown that the dynamical behaviour of the XADS does not differ noticeable when lead is used

  4. Experimental study on the thorium-loaded accelerator-driven system at the Kyoto Univ. critical assembly

    SciTech Connect

    Pyeon, C. H.; Yagi, T.; Lim, J. Y.; Misawa, T.

    2012-07-01

    The experimental study on the thorium-loaded accelerator-driven system (ADS) is conducted in the Kyoto Univ. Critical Assembly (KUCA). The experiments are carried out in both the critical and subcritical states for attaining the reaction rates of the thorium capture and fission reactions. In the critical system, the thorium plate irradiation experiment is carried out for the thorium capture and fission reactions. From the results of the measurements, the thorium fission reactions are obtained apparently in the critical system, and the C/E values of reaction rates show the accuracy of relative difference of about 30%. In the ADS experiments with 14 MeV neutrons and 100 MeV protons, the subcritical experiments are carried out in the thorium-loaded cores to obtain the capture reaction rates through the measurements of {sup 115}In(n, {gamma}){sup 116m}In reactions. The results of the experiments reveal the difference between the reaction rate distributions for the change in not only the neutron spectrum but also the external neutron source. The comparison between the measured and calculated reaction rate distributions demonstrates a discrepancy of the accuracy of reaction rate analyses of thorium capture reactions through the thorium-loaded ADS experiments with 14 MeV neutrons. Hereafter, kinetic experiments are planned to be carried out to deduce the delayed neutron decay constants and subcriticality using the pulsed neutron method. (authors)

  5. A beamline systems model for Accelerator-Driven Transmutation Technology (ADTT) facilities

    NASA Astrophysics Data System (ADS)

    Todd, Alan M. M.; Paulson, C. C.; Peacock, M. A.; Reusch, M. F.

    1995-09-01

    A beamline systems code, that is being developed for Accelerator-Driven Transmutation Technology (ADTT) facility trade studies, is described. The overall program is a joint Grumman, G. H. Gillespie Associates (GHGA) and Los Alamos National Laboratory effort. The GHGA Accelerator Systems Model (ASM) has been adopted as the framework on which this effort is based. Relevant accelerator and beam transport models from earlier Grumman systems codes are being adapted to this framework. Preliminary physics and engineering models for each ADTT beamline component have been constructed. Examples noted include a Bridge Coupled Drift Tube Linac (BCDTL) and the accelerator thermal system. A decision has been made to confine the ASM framework principally to beamline modeling, while detailed target/blanket, balance-of-plant and facility costing analysis will be performed externally. An interfacing external balance-of-plant and facility costing model, which will permit the performance of iterative facility trade studies, is under separate development. An ABC (Accelerator Based Conversion) example is used to highlight the present models and capabilities.

  6. A beamline systems model for Accelerator-Driven Transmutation Technology (ADTT) facilities

    SciTech Connect

    Todd, Alan M. M.; Paulson, C. C.; Peacock, M. A.; Reusch, M. F.

    1995-09-15

    A beamline systems code, that is being developed for Accelerator-Driven Transmutation Technology (ADTT) facility trade studies, is described. The overall program is a joint Grumman, G. H. Gillespie Associates (GHGA) and Los Alamos National Laboratory effort. The GHGA Accelerator Systems Model (ASM) has been adopted as the framework on which this effort is based. Relevant accelerator and beam transport models from earlier Grumman systems codes are being adapted to this framework. Preliminary physics and engineering models for each ADTT beamline component have been constructed. Examples noted include a Bridge Coupled Drift Tube Linac (BCDTL) and the accelerator thermal system. A decision has been made to confine the ASM framework principally to beamline modeling, while detailed target/blanket, balance-of-plant and facility costing analysis will be performed externally. An interfacing external balance-of-plant and facility costing model, which will permit the performance of iterative facility trade studies, is under separate development. An ABC (Accelerator Based Conversion) example is used to highlight the present models and capabilities.

  7. Neutron cross-sections above 20 MeV for design and modeling of accelerator driven systems

    NASA Astrophysics Data System (ADS)

    Blomgren, J.

    2007-02-01

    One of the outstanding new developments in the field of partitioning and transmutation (P{&}T) concerns accelerator-driven systems (ADS) which consist of a combination of a high-power, high-energy accelerator, a spallation target for neutron production and a sub-critical reactor core. The development of the commercial critical reactors of today motivated a large effort on nuclear data up to about 20 MeV, and presently several million data points can be found in various data libraries. At higher energies, data are scarce or even non-existent. With the development of nuclear techniques based on neutrons at higher energies, nowadays there is a need also for higher-energy nuclear data. To provide alternative to this lack of data, a wide program on neutron-induced data related to ADS for P{&}T is running at the 20-180 MeV neutron beam facility at `The Svedberg Laboratory' (TSL), Uppsala. The programme encompasses studies of elastic scattering, inelastic neutron production, i.e., (n, xn') reactions, light-ion production, fission and production of heavy residues. Recent results are presented and future program of development is outlined.

  8. Experimental results from the VENUS-F critical reference state for the GUINEVERE accelerator driven system project

    SciTech Connect

    Uyttenhove, W.; Baeten, P.; Kochetkov, A.; Vittiglio, G.; Wagemans, J.; Ban, G.; Lecolley, F.R.; Lecouey, J.L.; Marie, N.; Steckmeyer, J.C.; Billebaud, A.; Chabod, S.; Thyebault, H.E.; Dessagne, P.; Kerveno, M.; Mellier, F.

    2012-12-15

    The GUINEVERE (Generation of Uninterrupted Intense Neutron pulses at the lead Venus Reactor) project was launched in 2006 within the framework of FP6 EUROTRANS in order to validate online reactivity monitoring and subcriticality level determination in accelerator driven systems (ADS). Therefore, the VENUS reactor at SCK.CEN in Mol, Belgium, was modified towards a fast core (VENUS-F) and coupled to the GENEPI-3C accelerator built by CNRS. The accelerator can operate in both continuous and pulsed mode. The VENUS-F core is loaded with enriched Uranium and reflected with solid lead. A well-chosen critical reference state is indispensable for the validation of the online subcriticality monitoring methodology. Moreover, a benchmarking tool is required for nuclear data research and code validation. In this paper, the design and the importance of the critical reference state for the GUINEVERE project are motivated. The results of the first experimental phase on the critical core are presented. The control rods worth is determined by the positive period method and the application of the Modified Source Multiplication (MSM) method allows the determination of the worth of the safety rods. The results are implemented in the VENUS-F core certificate for full exploitation of the critical core. (authors)

  9. Assessment of americium and curium transmutation in magnesia based targets in different spectral zones of an experimental accelerator driven system

    NASA Astrophysics Data System (ADS)

    Haeck, W.; Malambu, E.; Sobolev, V. P.; Aït Abderrahim, H.

    2006-06-01

    The potential to incinerate minor actinides (MA) in a sub-critical accelerator-driven system (ADS) is a subject of study in several countries where nuclear power plants are present. The performance of the MYRRHA experimental ADS, as to the transmutation of Am and Cm in the inert matrix fuel (IMF) samples consisting of 40 vol.% (Cm0.1Am0.5Pu0.4)O1.88 fuel and 60 vol.% MgO matrix with a density of 6.077 g cm-3 in three various spectrum regions, were analysed at the belgian nuclear research centre SCK · CEN. The irradiation period of 810 effective full power days (EFPD) followed by a storage period of 2 years was considered. The ALEPH code system currently under development at SCK · CEN was used to carry out this study. The total amount of MA is shown to decrease in all three considered cases. For Am, the decrease is the largest in the reflector (89% decrease) but at the cost of a net Cm production (92% increase). In the two other positions (inside the core region), 20-30% of Am has disappeared but with a lower production of Cm (between 7% and 11%). In the reflector, a significant build-up of long-lived 245Cm, 246Cm, 247Cm and 248Cm was also observed while the production of these isotopes is 10-1000 times smaller in the core. The reduction of the Pu content is also the highest in the reflector position (41%). In the other positions the incinerated amount of Pu is much smaller: 1-5%.

  10. Monitoring method for neutron flux for a spallation target in an accelerator driven sub-critical system

    NASA Astrophysics Data System (ADS)

    Zhao, Qiang, He, Zhi-Yong; Yang, Lei; Zhang, Xue-Ying; Cui, Wen-Juan; Chen, Zhi-Qiang; Xu, Hu-Shan

    2016-07-01

    In this paper, we study a monitoring method for neutron flux for the spallation target used in an accelerator driven sub-critical (ADS) system, where a spallation target located vertically at the centre of a sub-critical core is bombarded vertically by high-energy protons from an accelerator. First, by considering the characteristics in the spatial variation of neutron flux from the spallation target, we propose a multi-point measurement technique, i.e. the spallation neutron flux should be measured at multiple vertical locations. To explain why the flux should be measured at multiple locations, we have studied neutron production from a tungsten target bombarded by a 250 MeV-proton beam with Geant4-based Monte Carlo simulations. The simulation results indicate that the neutron flux at the central location is up to three orders of magnitude higher than the flux at lower locations. Secondly, we have developed an effective technique in order to measure the spallation neutron flux with a fission chamber (FC), by establishing the relation between the fission rate measured by FC and the spallation neutron flux. Since this relation is linear for a FC, a constant calibration factor is used to derive the neutron flux from the measured fission rate. This calibration factor can be extracted from the energy spectra of spallation neutrons. Finally, we have evaluated the proposed calibration method for a FC in the environment of an ADS system. The results indicate that the proposed method functions very well. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03010000 and XDA03030000) and the National Natural Science Foundation of China(91426301).

  11. Neutrino physics with accelerator driven subcritical reactors

    NASA Astrophysics Data System (ADS)

    Ciuffoli, Emilio; Evslin, Jarah; Zhao, Fengyi

    2016-01-01

    Accelerator driven system (ADS) subcritical nuclear reactors are under development around the world. They will be intense sources of free, 30-55 MeV μ + decay at rest {overline{ν}}_{μ } . These ADS reactor neutrinos can provide a robust test of the LSND anomaly and a precise measurement of the leptonic CP-violating phase δ, including sign(cos(δ)). The first phase of many ADS programs includes the construction of a low energy, high intensity proton or deuteron accelerator, which can yield competitive bounds on sterile neutrinos.

  12. High-value use of weapons-plutonium by burning in molten salt accelerator-driven subcritical systems or reactors

    SciTech Connect

    Bowman, C.D.; Venneri, F.

    1993-11-01

    The application of thermal-spectrum molten-salt reactors and accelerator-driven subcritical systems to the destruction of weapons-return plutonium is considered from the perspective of deriving the maximum societal benefit. The enhancement of electric power production from burning the fertile fuel {sup 232}Th with the plutonium is evaluated. Also the enhancement of destruction of the accumulated waste from commercial nuclear reactors is considered using the neutron-rich weapons plutonium. Most cases examined include the concurrent transmutation of the long-lived actinide and fission product waste ({sup 99}Tc, {sup 129}I, {sup 135}Cs, {sup 126}Sn and {sup 79}Se).

  13. Front-end and back-end electrochemistry of molten salt in accelerator-driven transmutation systems

    SciTech Connect

    Williamson, M.A.; Venneri, F.

    1995-07-01

    The objective of this work is to develop preparation and clean-up processes for the fuel and carrier salt in the Los Alamos Accelerator-Driven Transmutation Technology molten salt nuclear system. The front-end or fuel preparation process focuses on the removal of fission products, uranium, and zirconium from spent nuclear fuel by utilizing electrochemical methods (i.e., electrowinning). The same method provides the separation of the so-called noble metal fission products at the back-end of the fuel cycle. Both implementations would have important diversion safeguards. The proposed separation processes and a thermodynamic analysis of the electrochemical separation method are presented.

  14. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W.

    2016-02-01

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  15. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac.

    PubMed

    Wu, Q; Ma, H Y; Yang, Y; Sun, L T; Zhang, X Z; Zhang, Z M; Zhao, H Y; He, Y; Zhao, H W

    2016-02-01

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  16. ORIGEN2 simulation of the Los Alamos accelerator-driven transmutation system

    SciTech Connect

    Landeyro, P.A. ); Buccafurni, A.; Orazi, A. )

    1992-01-01

    This work aims at analyzing different actinide-burning systems to evaluate their performance and verify the possibility of eliminating, or at least reducing, the storage time for nuclear wastes in the final repository. To achieve these goals, two steps are added to the normal fuel cycle: partitioning and transmutation. In the partitioning step, the actinides are extracted from the high-level wastes produced in reprocessing plants, while during the transmutation step, the actinides are burned. To evaluate the potential performance of the different systems suitable for actinide transmutation, it is necessary to determine and analyze the parameters that influence actinide burning as well as to compare the potential risk due to the waste produced by each system with that associated with radioactive materials existing in nature. Another important parameter to consider is the ratio between the transmutation and generation rates, which shows how fast the system burns actinides. For these considerations, an analysis of the parameters that influence actinide burning are followed by an evaluation by means of the ORIGEN2 generation and depletion code that is as accurate as possible.

  17. Kinetics of accelerator driven devices

    SciTech Connect

    Perry, R.T.; Buksa, J.; Houts, M.

    1994-09-01

    Kinetic calculations were made to show that subcritical accelerator driven devices are robust and stable. The calculations show that large changes in reactivity that would lead to an uncontrollable excursion in a reactor would lead only to a new power level in subcritical device. Calculations were also made to show the rate of power changes resulting from startup and shutdown, and that methods also exist for continuously monitoring the reactivity of a subcritical system.

  18. Neutronics Study on Accelerator Driven Subcritical Systems with Thorium-Based Fuel for Comparison Between Solid and Molten-Salt Fuels

    SciTech Connect

    Ishimoto, Shunsuke; Ishibashi, Kenji; Tenzou, Hideki; Sasa, Toshinobu

    2002-06-15

    Since thorium is an abundant fertile material, there is hope for the thorium-cycle fuels for an accelerator driven subcritical system (ADS). The ADS utilizes neutrons, which are generated by high-energy protons of giga-electron-volt-grade, but cross sections for the interaction of high-energy particles are not available for use in current ADS engineering design. In this paper the neutron behavior in the ADS target based on the related experimental data is clarified, and the feasibility of the ADS regarding both the molten salts (Flibe: {sup 7}LiF-BeF{sub 2}-ThF{sub 4}-{sup 233}UF{sub 4}, chloride: NaCl-ThCl{sub 4}-{sup 233}UCl{sub 4}) and oxide ([Th, {sup 233}U]O{sub 2}) fuels is examined. The difference between the experiment and the calculated result at the ADS high-energy region is discussed. In a comparison of the fuels, the time evolution of k{sub eff} and the beam current in the burning period are calculated. The calculated results suggest that the ADS with solid fuel has better future prospects than that with molten-salt fuels. The ADS with Flibe molten-salt fuel tends to require a high beam current and consequently needs the installation of a metallic spallation target and the continuous removal for fission products and protactinium. In comparison with the Flibe fuel, the ADS with chloride fuel has a flux distribution that is similar to a solid fuel reactor.

  19. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac.

    PubMed

    Wu, Q; Ma, H Y; Yang, Y; Sun, L T; Zhang, X Z; Zhang, Z M; Zhao, H Y; He, Y; Zhao, H W

    2016-02-01

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented. PMID:26932075

  20. Modelling the behaviour of oxide fuels containing minor actinides with urania, thoria and zirconia matrices in an accelerator-driven system

    NASA Astrophysics Data System (ADS)

    Sobolev, V.; Lemehov, S.; Messaoudi, N.; Van Uffelen, P.; Aı̈t Abderrahim, H.

    2003-06-01

    The Belgian Nuclear Research Centre, SCK • CEN, is currently working on the pre-design of the multipurpose accelerator-driven system (ADS) MYRRHA. A demonstration of the possibility of transmutation of minor actinides and long-lived fission products with a realistic design of experimental fuel targets and prognosis of their behaviour under typical ADS conditions is an important task in the MYRRHA project. In the present article, the irradiation behaviour of three different oxide fuel mixtures, containing americium and plutonium - (Am,Pu,U)O 2- x with urania matrix, (Am,Pu,Th)O 2- x with thoria matrix and (Am,Y,Pu,Zr)O 2- x with inert zirconia matrix stabilised by yttria - were simulated with the new fuel performance code MACROS, which is under development and testing at the SCK • CEN. All the fuel rods were considered to be of the same design and sizes: annular fuel pellets, helium bounded with the stainless steel cladding, and a large gas plenum. The liquid lead-bismuth eutectic was used as coolant. Typical irradiation conditions of the hottest fuel assembly of the MYRRHA subcritical core were pre-calculated with the MCNPX code and used in the following calculations as the input data. The results of prediction of the thermo-mechanical behaviour of the designed rods with the considered fuels during three irradiation cycles of 90 EFPD are presented and discussed.

  1. Experimental results from the VENUS-F critical reference state for the GUINEVERE accelerator driven system project

    SciTech Connect

    Uyttenhove, W.; Baeten, P.; Ban, G.; Billebaud, A.; Chabod, S.; Dessagne, P.; Kerveno, M.; Kochetkov, A.; Lecolley, F. R.; Lecouey, J. L.; Marie, N.; Mellier, F.; Steckmeyer, J. C.; Thyebault, H. E.; Vittiglio, G.; Wagemans, J.

    2011-07-01

    The GUINEVERE (Generation of Uninterrupted Intense Neutron pulses at the lead Venus Reactor) project was launched in 2006 within the framework of FP6 EUROTRANS in order to validate on-line reactivity monitoring and subcriticality level determination in Accelerator Driven Systems. Therefore the VENUS reactor at SCK.CEN in Mol (Belgium) was modified towards a fast core (VENUS-F) and coupled to the GENEPI-3C accelerator built by CNRS The accelerator can operate in both continuous and pulsed mode. The VENUS-F core is loaded with enriched Uranium and reflected with solid lead. A well-chosen critical reference state is indispensable for the validation of the on-line subcriticality monitoring methodology. Moreover a benchmarking tool is required for nuclear data research and code validation. In this paper the design and the importance of the critical reference state for the GUINEVERE project are motivated. The results of the first experimental phase on the critical core are presented. The control rods worth is determined by the rod drop technique and the application of the Modified Source Multiplication (MSM) method allows the determination of the worth of the safety rods. The results are implemented in the VENUS-F core certificate for full exploitation of the critical core. (authors)

  2. Reduction of the Radiotoxicity of Spent Nuclear Fuel Using a Two-Tiered System Comprising Light Water Reactors and Accelerator-Driven Systems

    SciTech Connect

    H.R. Trellue

    2003-06-01

    Two main issues regarding the disposal of spent nuclear fuel from nuclear reactors in the United States in the geological repository Yucca Mountain are: (1) Yucca Mountain is not designed to hold the amount of fuel that has been and is proposed to be generated in the next few decades, and (2) the radiotoxicity (i.e., biological hazard) of the waste (particularly the actinides) does not decrease below that of natural uranium ore for hundreds of thousands of years. One solution to these problems may be to use transmutation to convert the nuclides in spent nuclear fuel to ones with shorter half-lives. Both reactor and accelerator-based systems have been examined in the past for transmutation; there are advantages and disadvantages associated with each. By using existing Light Water Reactors (LWRs) to burn a majority of the plutonium in spent nuclear fuel and Accelerator-Driven Systems (ADSs) to transmute the remainder of the actinides, the benefits of each type of system can be realized. The transmutation process then becomes more efficient and less expensive. This research searched for the best combination of LWRs with multiple recycling of plutonium and ADSs to transmute spent nuclear fuel from past and projected nuclear activities (assuming little growth of nuclear energy). The neutronic design of each system is examined in detail although thermal hydraulic performance would have to be considered before a final system is designed. The results are obtained using the Monte Carlo burnup code Monteburns, which has been successfully benchmarked for MOX fuel irradiation and compared to other codes for ADS calculations. The best combination of systems found in this research includes 41 LWRs burning mixed oxide fuel with two recycles of plutonium ({approx}40 years operation each) and 53 ADSs to transmute the remainder of the actinides from spent nuclear fuel over the course of 60 years of operation.

  3. High-intensity cyclotrons for radioisotope production and accelerator driven systems

    NASA Astrophysics Data System (ADS)

    Jongen, Y.; Vandeplassche, D.; Kleeven, W.; Beeckman, W.; Zaremba, S.; Lannoye, G.; Stichelbaut, F.

    2002-04-01

    IBA recently proposed a new method to extract high-intensity positive ion beams from a cyclotron based on the concept of auto-extraction. We review the design of a 14 MeV, multi-milliampere cyclotron using this new technology. IBA is also involved in the design of the accelerator system foreseen to drive the MYRRHA facility, a multipurpose neutron source developed jointly by SCK-CEN and IBA.

  4. A version of the Trasco Intense Proton Source optimized for accelerator driven system purposes

    NASA Astrophysics Data System (ADS)

    Ciavola, G.; Celona, L.; Gammino, S.; Presti, M.; Andò, L.; Passarello, S.; Zhang, XZh.; Consoli, F.; Chines, F.; Percolla, C.; Calzona, V.; Winkler, M.

    2004-05-01

    A full set of measurements of the magnetic field has been carried out to define a different design of the TRASCO Intense Proton Source (TRIPS) magnetic system, based on permanent magnets, in order to increase the reliability of the source. The two coils of the source generate a maximum field of 150 mT and the optimum field was determined around 95 mT. The OPERA-3D package was used to simulate the magnetic field and a new magnetic system was designed as a combination of three rings of NdFeB magnets and soft iron. The high voltage insulation has been completely modified, in order to avoid any electronics at 80 kV voltage. The description of the magnetic measurements and the comparison with the simulations are presented, along with the mechanical design of the new version permanent magnet TRIPS (PM-TRIPS) and the new design of the extraction system. Finally the modification of the low energy beam transfer line (LEBT), which now includes a 30° bending magnet, will be outlined, with special regard to the accelerator availability improvement which can be obtained with the installation of two PM-TRIPS sources or more on the LEBT.

  5. Transient Thermo-Hydraulic Analysis of the Windowless Target System for the Lead Bismuth Eutectic Cooled Accelerator Driven System

    SciTech Connect

    Bianchi, Fosco; Ferri, Roberta; Moreau, Vincent

    2006-07-01

    The target system, whose function is to supply an external neutron source to the ADS sub-critical core to sustain the neutron chain reaction, is the most critical part of an ADS being subject to severe thermo-mechanical loading and material damage due to accelerator protons and fission neutrons. A windowless option was chosen as reference configuration for the target system of the LBE-cooled ADS within the European PDS-XADS project in order to reduce the material damage and to increase its life. This document deals with the thermo-hydraulic results of the calculations performed with STAR-CD and RELAP5 codes for studying the behaviour of the windowless target system during off-normal operating conditions. It also reports a description of modifications properly implemented in the codes needed for this analysis. The windowless target system shows a satisfactory thermo-hydraulic behaviour for the analysed accidents, except for the loss of both pumps without proton beam shut-off and the beam trips lasting more than one second. (authors)

  6. Design and test of a superconducting magnet in a linear accelerator for an Accelerator Driven Subcritical System

    NASA Astrophysics Data System (ADS)

    Peng, Quanling; Xu, Fengyu; Wang, Ting; Yang, Xiangchen; Chen, Anbin; Wei, Xiaotao; Gao, Yao; Hou, Zhenhua; Wang, Bing; Chen, Yuan; Chen, Haoshu

    2014-11-01

    A batch superconducting solenoid magnet for the ADS proton linear accelerator has been designed, fabricated, and tested in a vertical dewar in Sept. 2013. A total of ten superconducting magnets will be installed into two separate cryomodules. Each cryomodule contains six superconducting spoke RF cavities for beam acceleration and five solenoid magnets for beam focusing. The multifunction superconducting magnet contains a solenoid for beam focusing and two correctors for orbit correction. The design current for the solenoid magnet is 182 A. A quench performance test shows that the operating current of the solenoid magnet can reach above 300 A after natural quenching on three occasions during current ramping (260 A, 268 A, 308 A). The integrated field strength and leakage field at the nearby superconducting spoke cavities all meet the design requirements. The vertical test checked the reliability of the test dewar and the quench detection system. This paper presents the physical and mechanical design of the batch magnets, the quench detection technique, field measurements, and a discussion of the residual field resulting from persistent current effects.

  7. Accelerator driven sub-critical core

    SciTech Connect

    McIntyre, Peter M; Sattarov, Akhdiyor

    2015-03-17

    Systems and methods for operating an accelerator driven sub-critical core. In one embodiment, a fission power generator includes a sub-critical core and a plurality of proton beam generators. Each of the proton beam generators is configured to concurrently provide a proton beam into a different area of the sub-critical core. Each proton beam scatters neutrons within the sub-critical core. The plurality of proton beam generators provides aggregate power to the sub-critical core, via the proton beams, to scatter neutrons sufficient to initiate fission in the sub-critical core.

  8. Basic concept for an accelerator-driven subcritical system to be used as a long-pulse neutron source for Condensed Matter research

    NASA Astrophysics Data System (ADS)

    Vivanco, R.; Ghiglino, A.; de Vicente, J. P.; Sordo, F.; Terrón, S.; Magán, M.; Perlado, J. M.; Bermejo, F. J.

    2014-12-01

    A model for an accelerator-driven subcritical system to be operated as a source of cold neutrons for Condensed Matter research is developed at the conceptual level. Its baseline layout relies upon proven accelerator, spalattion target and fuel array technologies, and consists in a proton accelerator able to deliver some 67.5 mA of proton beam with kinetic energy 0.6 GeV, a pulse length of 2.86 ms, and repetition rate of 14 Hz. The particle beam hits a target of conventional design that is surrounded by a multiplicative core made of fissile/fertile material, composed by a subcritical array of fuel bars made of aluminium Cermet cooled by light water poisoned with boric acid. Relatively low enriched uranium is chosen as fissile material. An optimisation of several parameters is carried out, using as components of the objective function several characteristics pertaining the cold neutron pulse. The results show that the optimal device will deliver up to 80% of the cold neutron flux expected for some of the ongoing projects using a significantly lower proton beam power than that managed in such projects. The total power developed within the core rises up to 22.8 MW, and the criticality range shifts to a final keff value of around 0.9 after the 50 days cycle.

  9. Optimum design of a moderator system based on dose calculation for an accelerator driven Boron Neutron Capture Therapy.

    PubMed

    Inoue, R; Hiraga, F; Kiyanagi, Y

    2014-06-01

    An accelerator based BNCT has been desired because of its therapeutic convenience. However, optimal design of a neutron moderator system is still one of the issues. Therefore, detailed studies on materials consisting of the moderator system are necessary to obtain the optimal condition. In this study, the epithermal neutron flux and the RBE dose have been calculated as the indicators to look for optimal materials for the filter and the moderator. As a result, it was found that a combination of MgF2 moderator with Fe filter gave best performance, and the moderator system gave a dose ratio greater than 3 and an epithermal neutron flux over 1.0×10(9)cm(-2)s(-1).

  10. Accelerator Driven Nuclear Energy: The Thorium Option

    SciTech Connect

    Raja, Rajendran

    2009-03-18

    Conventional nuclear reactors use enriched Uranium as fuel and produce nuclear waste which needs to be stored away for over 10,000 years. At the current rate of use, existing sources of Uranium will last for 50-100 years. We describe a solution to the problem that uses particle accelerators to produce fast neutrons that can be used to burn existing nuclear waste and produce energy. Such systems, initially proposed by Carlo Rubbia and collaborators in the 1990's, are being seriously considered by many countries as a possible solution to the green energy problem. Accelerator driven reactors operate in a sub-critical regime and, thus, are safer and can obtain energy from plentiful elements such as Thorium-232 and Uranium-238. What is missing is the high intensity (10MW) accelerator that produces 1 GeV protons. We will describe scenarios which if implemented will make such systems a reality.

  11. Accelerator-driven Transmutation of Waste

    NASA Astrophysics Data System (ADS)

    Venneri, Francesco

    1998-04-01

    Nuclear waste from commercial power plants contains large quantities of plutonium, other fissionable actinides, and long-lived fission products that are potential proliferation concerns and create challenges for the long-term storage. Different strategies for dealing with nuclear waste are being followed by various countries because of their geologic situations and their views on nuclear energy, reprocessing and non-proliferation. The current United States policy is to store unprocessed spent reactor fuel in a geologic repository. Other countries are opting for treatment of nuclear waste, including partial utilization of the fissile material contained in the spent fuel, prior to geologic storage. Long-term uncertainties are hampering the acceptability and eventual licensing of a geologic repository for nuclear spent fuel in the US, and driving up its cost. The greatest concerns are with the potential for radiation release and exposure from the spent fuel for tens of thousands of years and the possible diversion and use of the actinides contained in the waste for weapons construction. Taking advantage of the recent breakthroughs in accelerator technology and of the natural flexibility of subcritical systems, the Accelerator-driven Transmutation of Waste (ATW) concept offers the United States and other countries the possibility to greatly reduce plutonium, higher actinides and environmentally hazardous fission products from the waste stream destined for permanent storage. ATW does not eliminate the need for, but instead enhances the viability of permanent waste repositories. Far from being limited to waste destruction, the ATW concept also brings to the table new technologies that could be relevant for next-generation power producing reactors. In the ATW concept, spent fuel would be shipped to the ATW site where the plutonium, transuranics and selected long-lived fission products would be destroyed by fission or transmutation in their first and only pass through the

  12. Accelerator Driven Nuclear Energy: The Thorium Option

    SciTech Connect

    Raja, Rajendran

    2009-03-18

    Conventional nuclear reactors use enriched Uranium as fuel and produce nuclear waste which needs to be stored away for over 10,000 years.   At the current rate of use, existing sources of Uranium will last for 50-100 years.  We describe a solution to the problem that uses particle accelerators to produce fast neutrons that can be used to burn existing nuclear waste and produce energy.  Such systems, initially proposed by Carlo Rubbia and collaborators in the 1990's, are being seriously considered by many countries as a possible solution to the green energy problem.  Accelerator driven reactors operate in a sub-critical regime and, thus, are safer and can obtain energy from plentiful elements such as Thorium-232 and Uranium-238. What is missing is the high intensity (10MW) accelerator that produces 1 GeV protons. We will describe scenarios which if implemented will make such systems a reality.  

  13. Accelerator Driven Nuclear Energy: The Thorium Option

    ScienceCinema

    Raja, Rajendran

    2016-07-12

    Conventional nuclear reactors use enriched Uranium as fuel and produce nuclear waste which needs to be stored away for over 10,000 years.   At the current rate of use, existing sources of Uranium will last for 50-100 years.  We describe a solution to the problem that uses particle accelerators to produce fast neutrons that can be used to burn existing nuclear waste and produce energy.  Such systems, initially proposed by Carlo Rubbia and collaborators in the 1990's, are being seriously considered by many countries as a possible solution to the green energy problem.  Accelerator driven reactors operate in a sub-critical regime and, thus, are safer and can obtain energy from plentiful elements such as Thorium-232 and Uranium-238. What is missing is the high intensity (10MW) accelerator that produces 1 GeV protons. We will describe scenarios which if implemented will make such systems a reality.  

  14. Materials Testing for an Accelerator-Driven Subcritical Molten Salt Fission System: A look at the Materials Science of Molten Salt Corrosion

    NASA Astrophysics Data System (ADS)

    Sooby, Elizabeth; Balachandran, Shreyas; Foley, David; Hartwig, Karl; McIntyre, Peter; Phongikaroon, Supathorn; Pogue, Nathaniel; Simpson, Michael; Tripathy, Prabhat

    2011-10-01

    For an accelerator-driven subcritical molten salt fission core to survive its 50+ year fuel life, the primary vessel, heat exchanger, and various internal components must be made of materials that resist corrosion and radiation damage in a high-temperature environment, (500-800 C). An experimental study of the corrosion behavior of candidate metals in contact with molten salt is being conducted at the Center for Advanced Energy Studies. Initial experiments have been run on Nb, Ta, Ni, two zirconium alloys, Hastelloy-N, and a series of steel alloys to form a base line for corrosion in both chloride and bromide salt. Metal coupons were immersed in LiCl-KCl or LiBr-KBr at 700 C in an inert-atmosphere. Salt samples were extracted on a time schedule over a 24-hr period. The samples were analyzed using inductively coupled plasma-mass spectrometry to determine concentrations of metals from corrosion. Preliminary results will be presented.

  15. Development and analysis of a metal-fueled accelerator-driven burner

    SciTech Connect

    Lypsch, F.; Hill, R.N.

    1994-08-01

    The purpose of this paper is to compare the safety characteristics of an accelerator driven metal fueled fast system to a critical core on a consistent basis to determine how these characteristics are affected solely by subcritically of the system. To accomplish this an accelerator proton beam/tungsten neutron source model is surrounded by a subcritical blanket using metallic fuel and sodium as coolant. The consequences of typical accident transients, namely unprotected transient overpower (TOP), loss of heat sink (LOHS), and loss of flow (LOP) were calculated for the hybrid system and compared to corresponding results for a metal-fueled fast reactor. Results indicate that the subcritical system exhibits superior performance for TOP (reactivity-induced) transits; however, only in the critical system are reactivity feedbacks able to cause passive shutdown in the LOHS ad LOP events. Therefore, for a full spectrum of accident initiators considered, the overall safety behavior of accelerator-driven metal-fueled systems can neither be concluded to be worse nor to be better than advanced reactor designs which rely on passive safety features.

  16. Accelerator-driven molten-salt blankets: Physics issues

    SciTech Connect

    Houts, M.G.; Beard, C.A.; Buksa, J.J.; Davidson, J.W.; Durkee, J.W.; Perry, R.T.; Poston, D.I.

    1994-10-01

    A number of nuclear physics issues concerning the Los Alamos molten-salt accelerator-driven plutonium converter are discussed. General descriptions of several concepts using internal and external moderation are presented. Burnup and salt processing requirement calculations are presented for four concepts, indicating that both the high power density externally moderated concept and an internally moderated concept achieve total plutonium burnups approaching 90% at salt processing rates of less than 2 m{sup 3} per year. Beginning-of-life reactivity temperature coefficients and system kinetic response are also discussed. Future research should investigate the effect of changing blanket composition on operational and safety characteristics.

  17. Development of the accelerator-driven energy production concept

    SciTech Connect

    Venneri, F.; Beard, C.; Bowman, C.

    1996-10-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Accelerator Driven Transmutation Technology (ADTT) offers a means of generating nuclear energy in a clean, safe way that can be attractive to the general public. However, there are issues associated with the energy story (both at the system level and technical detail) that have to be seriously addressed before the scientific community, the public, and potential industrial sponsors can be compellingly convinced of its cost/benefit.

  18. Overall Design of the ADS Injector I Cryogenic System in China

    NASA Astrophysics Data System (ADS)

    Li, Shaopeng; Ge, Rui; Zhang, Zhuo; Liu, Yaping; Sang, Minjing; Bian, Lin; Han, Ruixiong; Zhang, Jiehao; Sun, Liangrui; Xu, Miaofu; Ye, Rui; Zhang, Jianqin

    The accelerator driven sub-critical system (ADS) in China is a kind of transmutation machine to minimize nuclear waste. As one of the important parts in ADS, injector will be built at IHEP,CAS. Injector I needs two cryomodules operating at 2K cryogenic environment to realize a 10MeVproton beam energy. Each cryomodule includes seven spoke cavities and sevensuperconducting magnets. This paper describes the overall design of the cryogenic system, including the cooling flow chart, heat loads estimation, the structure of the operation cryomodule and some of the key components.

  19. Separations technology development to support accelerator-driven transmutation concepts

    SciTech Connect

    Venneri, F.; Arthur, E.; Bowman, C.

    1996-10-01

    This is the final report of a one-year Laboratory-Directed Research and Development (LDRD) Project at the Los Alamos National Laboratory (LANL). This project investigated separations technology development needed for accelerator-driven transmutation technology (ADTT) concepts, particularly those associated with plutonium disposition (accelerator-based conversion, ABC) and high-level radioactive waste transmutation (accelerator transmutation of waste, ATW). Specific focus areas included separations needed for preparation of feeds to ABC and ATW systems, for example from spent reactor fuel sources, those required within an ABC/ATW system for material recycle and recovery of key long-lived radionuclides for further transmutation, and those required for reuse and cleanup of molten fluoride salts. The project also featured beginning experimental development in areas associated with a small molten-salt test loop and exploratory centrifugal separations systems.

  20. Accelerator-driven X-ray Sources

    SciTech Connect

    Nguyen, Dinh Cong

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  1. Research opportunities with compact accelerator-driven neutron sources

    NASA Astrophysics Data System (ADS)

    Anderson, I. S.; Andreani, C.; Carpenter, J. M.; Festa, G.; Gorini, G.; Loong, C.-K.; Senesi, R.

    2016-10-01

    Since the discovery of the neutron in 1932 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator-driven neutron sources (CANS) is becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target-moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS.

  2. Study of a multi-beam accelerator driven thorium reactor

    SciTech Connect

    Ludewig, H.; Aronson, A.

    2011-03-01

    The primary advantages that accelerator driven systems have over critical reactors are: (1) Greater flexibility regarding the composition and placement of fissile, fertile, or fission product waste within the blanket surrounding the target, and (2) Potentially enhanced safety brought about by operating at a sufficiently low value of the multiplication factor to preclude reactivity induced events. The control of the power production can be achieved by vary the accelerator beam current. Furthermore, once the beam is shut off the system shuts down. The primary difference between the operation of an accelerator driven system and a critical system is the issue of beam interruptions of the accelerator. These beam interruptions impose thermo-mechanical loads on the fuel and mechanical components not found in critical systems. Studies have been performed to estimate an acceptable number of trips, and the value is significantly less stringent than had been previously estimated. The number of acceptable beam interruptions is a function of the length of the interruption and the mission of the system. Thus, for demonstration type systems and interruption durations of 1sec < t < 5mins, and t > 5mins 2500/yr and 50/yr are deemed acceptable. However, for industrial scale power generation without energy storage type systems and interruption durations of t < 1sec., 1sec < t < 10secs., 10secs < t < 5mins, and t > 5mins, the acceptable number of interruptions are 25000, 2500, 250, and 3 respectively. However, it has also been concluded that further development is required to reduce the number of trips. It is with this in mind that the following study was undertaken. The primary focus of this study will be the merit of a multi-beam target system, which allows for multiple spallation sources within the target/blanket assembly. In this manner it is possible to ameliorate the effects of sudden accelerator beam interruption on the surrounding reactor, since the remaining beams will still

  3. Heavy Ion Accelerator-Driven Inertial Fusion

    NASA Astrophysics Data System (ADS)

    Hofmann, Ingo

    The idea of using accelerators in the production of energy by inertial confinement fusion has been developed since the mid-1970s. The basic concept is to use accelerated beams of heavy ions to provide energy to implode and ignite a small fusion pellet. Accelerators have been seen as attractive for this application due to their reliability, high repetition rate, and potential efficiency. They are therefore competitive with high power lasers at least for the commercial production of electrical power. This review summarizes part of the development and scientific efforts directed toward this application, which has been realized over time to be an extremely demanding one. Here we focus primarily on the rf linac/storage ring driver system approach and summarize the specific development that culminated in the European HIDIF study of the late 1990s. We also discuss some of the relevant followup accelerator studies.

  4. An overview of accelerator-driven transmutation technology

    SciTech Connect

    Heighway, E.A.

    1994-07-01

    Accelerator-Driven Transmutation Technology, or ADT{sup 2}, is a collection of programs that share a common theme - they each have at their heart an intense source of neutrons generated by a high-energy proton beam striking a heavy metal target. The beam energy, typically 1000 MeV, is enough for a single proton to smash a target atom into atomic fragments. This so-called spallation process generates large numbers of neutrons (around 20 to 30 per proton) amid the atomic debris. These neutrons are of high value because they can be used to transmute neighboring atoms by neutron capture. Three distinct ADT{sup 2} program elements will be described. These are ADEP - accelerator-driven energy production, ABC - accelerator based conversion (of plutonium) and ATW - accelerator transmutation of waste.

  5. Design and simulation of a wire position monitor for cryogenic systems in an ADS linac

    NASA Astrophysics Data System (ADS)

    Zhu, Hong-Yan; Dong, Lan; Li, Bo

    2014-08-01

    This paper introduces the design and simulation of a Wire Position Monitor (WPM) used in the cryogenic system of an Accelerator Driven System (ADS). The WPM is designed to monitor the contraction of cold masses during the cooling-down operation. In this paper, POISSON-2D electrostatic field software is used to calculate the best characteristic impedance for the WPM. Furthermore, the time domain signal of different end structures is theoretically analyzed and simulated. The coupling of electrodes and the influence of signal carrier size, which may influence the induced signal, are also discussed. Finally, the linearity of the induced voltage and the sensitivity of the WPM are analyzed. The time domain simulation results are consistent with the theoretical analysis. The influences of the coupling and carrier size are very small, and the linearity of the normalized voltage is good within r/2.

  6. Tuner control system of Spoke012 SRF cavity for C-ADS injector I

    NASA Astrophysics Data System (ADS)

    Liu, Na; Sun, Yi; Wang, Guang-Wei; Mi, Zheng-Hui; Lin, Hai-Ying; Wang, Qun-Yao; Liu, Rong; Ma, Xin-Peng

    2016-09-01

    A new tuner control system for spoke superconducting radio frequency (SRF) cavities has been developed and applied to cryomodule I of the C-ADS injector I at the Institute of High Energy Physics, Chinese Academy of Sciences. We have successfully implemented the tuner controller based on Programmable Logic Controller (PLC) for the first time and achieved a cavity tuning phase error of ±0.7° (about ±4 Hz peak to peak) in the presence of electromechanical coupled resonance. This paper presents preliminary experimental results based on the PLC tuner controller under proton beam commissioning. Supported by Proton linac accelerator I of China Accelerator Driven sub-critical System (Y12C32W129)

  7. Neutron source in the MCNPX shielding calculating for electron accelerator driven facility

    SciTech Connect

    Zhong, Z.; Gohar, Y.

    2012-07-01

    Argonne National Laboratory (ANL) of USA and Kharkov Inst. of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of an experimental neutron source facility. It is an accelerator driven system (ADS) utilizing a subcritical assembly driven by electron accelerator. The facility will be utilized for performing basic and applied nuclear researches, producing medical isotopes, and training young nuclear specialists. Monte Carlo code MCNPX has been utilized as a design tool due to its capability to transport electrons, photons, and neutrons at high energies. However the facility shielding calculations with MCNPX need enormous computational resources and the small neutron yield per electron makes sampling difficulty for the Monte Carlo calculations. A method, based on generating and utilizing neutron source file, was proposed and tested. This method reduces significantly the required computer resources and improves the statistics of the calculated neutron dose outside the shield boundary. However the statistical errors introduced by generating the neutron source were not directly represented in the results, questioning the validity of this methodology, because an insufficiently sampled neutron source can cause error on the calculated neutron dose. This paper presents a procedure for the validation of the generated neutron source file. The impact of neutron source statistic on the neutron dose is examined by calculating the neutron dose as a function of the number of electron particles used for generating the neutron source files. When the value of the calculated neutron dose converges, it means the neutron source has scored sufficient records and statistic does not have apparent impact on the calculated neutron dose. In this way, the validity of neutron source and the shield analyses could be verified. (authors)

  8. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    SciTech Connect

    Wender, S. A.; Venneri, F.; Bowman, C. D.; Arthur, E. D.; Heighway, E.; Beard, C. A.; Bracht, R. R.; Buksa, J. J.; Chavez, W.; DeVolder, B. G.; Park, J. J.; Parker, R. B.; Pillai, C.; Pitcher, E.; Potter, R. C.; Reid, R. S.; Russell, G. J.; Trujillo, D. A.; Weinacht, D. J.; Wilson, W. B.

    1995-09-15

    A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning or transmutation of commercial spent fuel or energy production from thorium. The experiment will be operated at power levels up to 5 MWt.

  9. A small scale accelerator-driven subcritical assembly demonstration experiment at LAMPF

    SciTech Connect

    Wender, S.A.

    1994-12-31

    The coupling of a neutron-producing accelerator with a sub-critical fission assembly has been proposed at Los Alamos as a method of addressing (1) the destruction of weapons-grade plutonium, (2) the reduction of nuclear waste from commercial reactors and, (3) the generation of power using the thorium/uranium cycle. A small scale experiment is described that will demonstrate many of the aspects of this accelerator-driven transmutation technology. This experiment will use the high-power proton beam from the LAMPF accelerator. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning, transmutation of commercial spent fuel and energy production from thorium. The experiment will be operated at power levels around 5 MWt.

  10. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    SciTech Connect

    Wender, S.A.; Venneri, F.; Bowman, C.D.; Arthur, E.D.; Heighway, E.A.; Beard, C.A.; Bracht, R.R.; Buksa, J.J.; Chavez, W.; DeVolder, B.G.

    1994-10-01

    A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning or transmutation of commercial spent fuel or energy production from thorium. The experiment will be operated at power levels up to 5 MW{sub t}.

  11. Lifshitz-like systems and AdS null deformations

    SciTech Connect

    Narayan, K.

    2011-10-15

    Following K. Balasubramanian and K. Narayan [J. High Energy Phys. 08 (2010) 014], we discuss certain lightlike deformations of AdS{sub 5}xX{sup 5} in type IIB string theory sourced by a lightlike dilaton {Phi}(x{sup +}) dual to the N=4 super Yang-Mills theory with a lightlike varying gauge coupling. We argue that, in the case where the x{sup +} direction is noncompact, these solutions describe anisotropic 3+1-dim Lifshitz-like systems with a potential in the x{sup +} direction generated by the lightlike dilaton. We then describe solutions of this sort with a linear dilaton. This enables a detailed calculation of two-point correlation functions of operators dual to bulk scalars and helps illustrate the spatial structure of these theories. Following this, we discuss a nongeometric string construction involving a compactification along the x{sup +} direction of this linear dilaton system. We also point out similar IIB axionic solutions. Similar bulk arguments for x{sup +}-noncompact can be carried out for deformations of AdS{sub 4}xX{sup 7} in M theory.

  12. Important requirements for RF generators for Accelerator-Driven Transmutation Technologies (ADTT)

    SciTech Connect

    Lynch, M.T.; Tallerico, P.J.; Lawrence, G.P.

    1994-09-01

    All Accelerator-Driven Transmutation applications require very large amounts of RF Power. For example, one version of a Plutonium burning system requires an 800-MeV, 80-mA, proton accelerator running at 100% duty factor. This accelerator requires approximately 110-MW of continuous RF power if one assumes only 10% reserve power for control of the accelerator fields. In fact, to minimize beam spill, the RF controls may need as much as 15 to 20% of reserve power. In addition, unlike an electron accelerator in which the beam is relativistic, a failed RF station can disturb the synchronism of the beam, possibly shutting down the entire accelerator. These issues and more lead to a set of requirements for the RF generators which are stringent, and in some cases, conflicting. In this paper, we will describe the issues and requirements, and outline a plan for RF generator development to meet the needs of the Accelerator-Driven Transmutation Technologies. The key issues which will be discussed include: operating efficiency, operating linearity, effect on the input power grid, bandwidth, gain, reliability, operating voltage, and operating current.

  13. LINAC for ADS application - accelerator technologies

    SciTech Connect

    Garnett, Robert W; Sheffreld, Richard L

    2009-01-01

    Sifnificant high-current, high-intensity accelerator research and development have been done in the recent past in the US, centered primarily at Los Alamos National Laboratory. These efforts have included designs for the Accelerator Production of Tritium Project, Accelerator Transmutation of Waste, and Accelerator Driven Systems, as well as many others. This past work and some specific design principles that were developed to optimie linac designs for ADS and other high-intensity applications will be discussed briefly.

  14. A New Type of Plasma Wakefield Accelerator Driven By Magnetowaves

    SciTech Connect

    Chen, Pisin; Chang, Feng-Yin; Lin, Guey-Lin; Noble, Robert J.; Sydora, Richard; /Alberta U.

    2011-09-12

    We present a new concept for a plasma wakefield accelerator driven by magnetowaves (MPWA). This concept was originally proposed as a viable mechanism for the 'cosmic accelerator' that would accelerate cosmic particles to ultra-high energies in the astrophysical setting. Unlike the more familiar plasma wakefield accelerator (PWFA) and the laser wakefield accelerator (LWFA) where the drivers, the charged-particle beam and the laser, are independently existing entities, MPWA invokes the high-frequency and high-speed whistler mode as the driver, which is a medium wave that cannot exist outside of the plasma. Aside from the difference in drivers, the underlying mechanism that excites the plasma wakefield via the ponderomotive potential is common. Our computer simulations show that under appropriate conditions, the plasma wakefield maintains very high coherence and can sustain high-gradient acceleration over many plasma wavelengths. We suggest that in addition to its celestial application, the MPWA concept can also be of terrestrial utility. A proof-of-principle experiment on MPWA would benefit both terrestrial and celestial accelerator concepts.

  15. Operation and reactivity measurements of an accelerator driven subcritical TRIGA reactor

    NASA Astrophysics Data System (ADS)

    O'Kelly, David Sean

    Experiments were performed at the Nuclear Engineering Teaching Laboratory (NETL) in 2005 and 2006 in which a 20 MeV linear electron accelerator operating as a photoneutron source was coupled to the TRIGA (Training, Research, Isotope production, General Atomics) Mark II research reactor at the University of Texas at Austin (UT) to simulate the operation and characteristics of a full-scale accelerator driven subcritical system (ADSS). The experimental program provided a relatively low-cost substitute for the higher power and complexity of internationally proposed systems utilizing proton accelerators and spallation neutron sources for an advanced ADSS that may be used for the burning of high-level radioactive waste. Various instrumentation methods that permitted ADSS neutron flux monitoring in high gamma radiation fields were successfully explored and the data was used to evaluate the Stochastic Pulsed Feynman method for reactivity monitoring.

  16. Applications of compact accelerator-driven neutron sources: An updated assessment from the perspective of materials research in Italy

    DOE PAGES

    Andreani, C.; Anderson, I. S.; Carpenter, J. M.; Festa, G.; Gorini, G.; Loong, C. -K.; Senesi, R.

    2014-12-24

    In 2005 the International Atomic Energy Agency (IAEA) in Vienna published a report [1] on ‘Development Opportunities of Small and Medium Scale Accelerator Driven Neutron Sources’ which summarized the prospect of smaller sources in supporting the large spallation neutron sources for materials characterization and instrumentation, a theme advocated by Bauer, Clausen, Mank, and Mulhauser in previous publications [2-4]. In 2010 the Union for Compact Accelerator-driven Neutron Sources (UCANS) was established [5], galvanizing cross-disciplinary collaborations on new source and neutronics development and expanded applications based on both slow-neutron scattering and other neutron-matter interactions of neutron energies ranging from 10⁻⁶ to 10²more » MeV [6]. Here, we first cover the recent development of ongoing and prospective projects of compact accelerator-driven neutron sources (CANS) but concentrate on prospective accelerators currently proposed in Italy. Two active R&D topics, irradiation effects on electronics and cultural heritage studies, are chosen to illustrate the impact of state-of-the-art CANS on these programs with respect to the characteristics and complementarity of the accelerator and neutronics systems as well as instrumentation development.« less

  17. Applications of compact accelerator-driven neutron sources: An updated assessment from the perspective of materials research in Italy

    SciTech Connect

    Andreani, C.; Anderson, I. S.; Carpenter, J. M.; Festa, G.; Gorini, G.; Loong, C. -K.; Senesi, R.

    2014-12-24

    In 2005 the International Atomic Energy Agency (IAEA) in Vienna published a report [1] on ‘Development Opportunities of Small and Medium Scale Accelerator Driven Neutron Sources’ which summarized the prospect of smaller sources in supporting the large spallation neutron sources for materials characterization and instrumentation, a theme advocated by Bauer, Clausen, Mank, and Mulhauser in previous publications [2-4]. In 2010 the Union for Compact Accelerator-driven Neutron Sources (UCANS) was established [5], galvanizing cross-disciplinary collaborations on new source and neutronics development and expanded applications based on both slow-neutron scattering and other neutron-matter interactions of neutron energies ranging from 10⁻⁶ to 10² MeV [6]. Here, we first cover the recent development of ongoing and prospective projects of compact accelerator-driven neutron sources (CANS) but concentrate on prospective accelerators currently proposed in Italy. Two active R&D topics, irradiation effects on electronics and cultural heritage studies, are chosen to illustrate the impact of state-of-the-art CANS on these programs with respect to the characteristics and complementarity of the accelerator and neutronics systems as well as instrumentation development.

  18. Molten salt considerations for accelerator-driven subcritical fission to close the nuclear fuel cycle

    NASA Astrophysics Data System (ADS)

    Sooby, Elizabeth; Adams, Marvin; Baty, Austin; Gerity, James; McIntyre, Peter; Melconian, Karie; Phongikaroon, Supathorn; Pogue, Nathaniel; Sattarov, Akhdiyor; Simpson, Michael; Tripathy, Prabhat; Tsevkov, Pavel

    2013-04-01

    The host salt selection, molecular modeling, physical chemistry, and processing chemistry are presented here for an accelerator-driven subcritical fission in a molten salt core (ADSMS). The core is fueled solely with the transuranics (TRU) and long-lived fission products (LFP) from used nuclear fuel. The neutronics and salt composition are optimized to destroy the transuranics by fission and the long-lived fission products by transmutation. The cores are driven by proton beams from a strong-focusing cyclotron stack. One such ADSMS system can destroy the transuranics in the used nuclear fuel produced by a 1GWe conventional reactor. It uniquely provides a method to close the nuclear fuel cycle for green nuclear energy.

  19. Molten salt considerations for accelerator-driven subcritical fission to close the nuclear fuel cycle

    SciTech Connect

    Sooby, Elizabeth; Baty, Austin; Gerity, James; McIntyre, Peter; Melconian, Karie; Pogue, Nathaniel; Sattarov, Akhdiyor; Adams, Marvin; Tsevkov, Pavel; Phongikaroon, Supathorn; Simpson, Michael; Tripathy, Prabhat

    2013-04-19

    The host salt selection, molecular modeling, physical chemistry, and processing chemistry are presented here for an accelerator-driven subcritical fission in a molten salt core (ADSMS). The core is fueled solely with the transuranics (TRU) and long-lived fission products (LFP) from used nuclear fuel. The neutronics and salt composition are optimized to destroy the transuranics by fission and the long-lived fission products by transmutation. The cores are driven by proton beams from a strong-focusing cyclotron stack. One such ADSMS system can destroy the transuranics in the used nuclear fuel produced by a 1GWe conventional reactor. It uniquely provides a method to close the nuclear fuel cycle for green nuclear energy.

  20. Disposition of nuclear waste using subcritical accelerator-driven systems

    SciTech Connect

    Venneri, F.; Li, N.; Williamson, M.; Houts, M.; Lawrence, G.

    1998-12-01

    Studies have shown that the repository long-term radiological risk is from the long-lived transuranics and the fission products Tc-99 and I-129, thermal loading concerns arise mainly form the short-lived fission products Sr-90 and Cs-137. In relation to the disposition of nuclear waste, ATW is expected to accomplish the following: (1) destroy over 99.9% of the actinides; (2) destroy over 99.9% of the Tc and I; (3) separate Sr and Cs (short half-life isotopes); (4) separate uranium; (5) produce electricity. In the ATW concept, spent fuel would be shipped to a ATW site where the plutonium, other transuranics and selected long-lived fission products would be destroyed by fission or transmutation in their only pass through the facility. This approach contrasts with the present-day reprocessing practices in Europe and Japan, during which high purity plutonium is produced and used in the fabrication of fresh mixed-oxide fuel (MOX) that is shipped off-site for use in light water reactors.

  1. Spallation Target Design for Accelerator-Driven Systems

    NASA Astrophysics Data System (ADS)

    Gohar, Yousry

    2010-06-01

    A design methodology for the lead-bismuth eutectic (LBE) spallation target has been developed and applied. This methodology includes the target interface with the subcritical assembly and the different engineering aspects of the target design, physics, heat-transfer, hydraulics, structural, radiological, and safety analyses. Several design constrains were defined and utilized for the target design process to satisfy different engineering requirements and to minimize the time and the cost of the design development. Target interface requirements with the subcritical assembly were defined based on performance parameters and material damage issues to enhance the lifetime of the target structure. Different structural materials were considered to define the most promising candidate based on the current database including radiation effects.

  2. LWR (Light Water Reactor) power plant simulations using the AD10 and AD100 systems

    SciTech Connect

    Wulff, W.; Cheng, H.S.; Chien, C.J.; Jang, J.Y.; Lin, H.C.; Mallen, A.N.; Wang, S.J.; Institute of Nuclear Energy Research, Lung-Tan; Tawian Power Co., Taipei; Brookhaven National Lab., Upton, NY; Institute of Nuclear Energy Research, Lung-Tan )

    1989-01-01

    Boiling (BWR) and Pressurized (PWR) Water Reactor Power Plants are being simulated at BNL with the AD10 and AD100 Peripheral Processor Systems. The AD10 system has been used for BWR simulations since 1984 for safety analyses, emergency training and optimization studies. BWR simulation capabilities have been implemented recently on the AD100 system and PWR simulation capabilities are currently being developed under the auspices of international cooperation. Modeling and simulation methods are presented with emphasis on the simulation of the Nuclear Steam Supply System. Results are presented for BWR simulation and performance characteristics are compared of the AD10 and AD100 systems. It will be shown that the AD100 simulates two times faster than two AD10 processors operating in parallel and that the computing capacity of one AD100 (with FMU processor) is twice as large as that of two AD10 processors. 9 refs., 5 figs., 1 tab.

  3. The MYRRHA ADS Project in Belgium Enters the Front End Engineering Phase

    NASA Astrophysics Data System (ADS)

    Schyns, M.; Aït Abderrahim, H.; Baeten, P.; Fernandez, R.; De Bruyn, D.

    MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a multipurpose research facility currently being developed at SCK•CEN. MYRRHA is based on the ADS (Accelerator Driven System) concept where a proton accelerator, a spallation target and a subcritical reactor are coupled. MYRRHA will demonstrate the ADS full concept by coupling these three components at a reasonable power level.

  4. Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron Source

    SciTech Connect

    Vainionpaa, J.H.; Gough, R.; Hoff, M.; Kwan, J.W.; Ludewigt,B.A.; Regis, M.J.; Wallig, J.G.; Wells, R.

    2007-02-15

    An over-dense microwave driven ion source capable ofproducing deuterium (or hydrogen) beams at 100-200 mA/cm2 and with atomicfraction>90 percent was designed and tested with an electrostaticlow energy beam transport section (LEBT). This ion source wasincorporatedinto the design of an Accelerator Driven Neutron Source(ADNS). The other key components in the ADNS include a 6 MeV RFQaccelerator, a beam bending and scanning system, and a deuterium gastarget. In this design a 40 mA D+ beam is produced from a 6 mm diameteraperture using a 60 kV extraction voltage. The LEBT section consists of 5electrodes arranged to form 2 Einzel lenses that focus the beam into theRFQ entrance. To create the ECR condition, 2 induction coils are used tocreate ~; 875 Gauss on axis inside the source chamber. To prevent HVbreakdown in the LEBT a magnetic field clamp is necessary to minimize thefield in this region. Matching of the microwave power from the waveguideto the plasma is done by an autotuner. We observed significantimprovement of the beam quality after installing a boron nitride linerinside the ion source. The measured emittance data are compared withPBGUNS simulations.

  5. CANCELLED Microwave Ion Source and Beam Injection for anAccelerator-Driven Neut ron Source

    SciTech Connect

    Vainionpaa, J.H.; Gough, R.; Hoff, M.; Kwan, J.W.; Ludewigt,B.A.; Regis, M.J.; Wallig, J.G.; Wells, R.

    2007-02-27

    An over-dense microwave driven ion source capable of producing deuterium (or hydrogen) beams at 100-200 mA/cm{sup 2} and with atomic fraction > 90% was designed and tested with an electrostatic low energy beam transport section (LEBT). This ion source was incorporated into the design of an Accelerator Driven Neutron Source (ADNS). The other key components in the ADNS include a 6 MeV RFQ accelerator, a beam bending and scanning system, and a deuterium gas target. In this design a 40 mA D{sup +} beam is produced from a 6 mm diameter aperture using a 60 kV extraction voltage. The LEBT section consists of 5 electrodes arranged to form 2 Einzel lenses that focus the beam into the RFQ entrance. To create the ECR condition, 2 induction coils are used to create {approx} 875 Gauss on axis inside the source chamber. To prevent HV breakdown in the LEBT a magnetic field clamp is necessary to minimize the field in this region. Matching of the microwave power from the waveguide to the plasma is done by an autotuner. They observed significant improvement of the beam quality after installing a boron nitride liner inside the ion source. The measured emittance data are compared with PBGUNS simulations.

  6. Basis and objectives of the Los Alamos Accelerator-Driven Transmutation technology project

    NASA Astrophysics Data System (ADS)

    Bowman, Charles D.

    1995-09-01

    The Accelerator-Driven Transmutation Technology (ADTT) Project carries three approaches for dealing with waste from the defense and commercial nuclear energy enterprise. First, the problem of excess weapons plutonium in the U.S. and Russia originating both from stockpile reductions and from defense production site clean-up is one of significant current and long-term concern. The ADTT technology offers the possibility of almost complete destruction of this plutonium by fission. The technology might be particularly effective for destruction of the low quality plutonium from defense site clean-up since the system does not require the fabrication of the waste into fuel assemblies, does not require reprocessing and refabrication, and can tolerate a high level of impurities in the feed stream. Second, the ADTT system also can destroy the plutonium, other higher actinide, and long-lived fission product from commercial nuclear waste which now can only be dealt with by geologic storage. And finally, and probably most importantly the system can be used for the production of virtually unlimited electric power from thorium with concurrent destruction of its long-lived waste components so that geologic containment for them is not required. In addition plutonium is not a significant byproduct of the power generation so that non-proliferation concerns about nuclear power are almost completely eliminated. All of the ADTT systems operate with an accelerator supplementing the neutrons which in reactors are provided only by the fission process, and therefore the system can be designed to eliminate the possibility for a runaway chain reaction. The means for integration of the accelerator into nuclear power technology in order to make these benefits possible is described including estimates of accelerator operating parameters required for the three objectives.

  7. Burnup calculations for KIPT accelerator driven subcritical facility using Monte Carlo computer codes-MCB and MCNPX.

    SciTech Connect

    Gohar, Y.; Zhong, Z.; Talamo, A.; Nuclear Engineering Division

    2009-06-09

    Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an electron accelerator driven subcritical (ADS) facility, using the KIPT electron accelerator. The neutron source of the subcritical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The electron beam has a uniform spatial distribution and electron energy in the range of 100 to 200 MeV. The main functions of the subcritical assembly are the production of medical isotopes and the support of the Ukraine nuclear power industry. Neutron physics experiments and material structure analyses are planned using this facility. With the 100 KW electron beam power, the total thermal power of the facility is {approx}375 kW including the fission power of {approx}260 kW. The burnup of the fissile materials and the buildup of fission products reduce continuously the reactivity during the operation, which reduces the neutron flux level and consequently the facility performance. To preserve the neutron flux level during the operation, fuel assemblies should be added after long operating periods to compensate for the lost reactivity. This process requires accurate prediction of the fuel burnup, the decay behavior of the fission produces, and the introduced reactivity from adding fresh fuel assemblies. The recent developments of the Monte Carlo computer codes, the high speed capability of the computer processors, and the parallel computation techniques made it possible to perform three-dimensional detailed burnup simulations. A full detailed three-dimensional geometrical model is used for the burnup simulations with continuous energy nuclear data libraries for the transport calculations and 63-multigroup or one group cross sections libraries for the depletion calculations. Monte Carlo Computer code MCNPX and MCB are utilized for this study. MCNPX transports the

  8. Accelerator-Driven Neutron Source for Cargo Screening

    SciTech Connect

    Ludewigt, B.A.; Bleuel, D.L.; Hoff, M.D.; Kwan, J.W.; Li, D.; Ratti, A.; Staples, J.W.; Virostek, S.P.; Wells, R.P.

    2006-11-15

    Advanced neutron interrogation systems for the screening ofsea-land cargo containers for shielded special nuclear materials (SNM)require a high-yield neutron source to achieve the desired detectionprobability, false alarm rate, and throughput. An accelerator-drivenneutron source is described that produces a forward directed beam ofhigh-energy (up to 8.5 MeV) neutrons utilizing the D(d,n)3He reaction atdeuteron beam energies of up to 6 MeV. The key components of the neutronsource are a high-current RFQ accelerator and an innovative neutronproduction target. A microwave-driven deuteron source is coupled to anelectrostatic LEBT that injects a 40 mA D+-beam into a 6 MeV, 5.1meter-long, 200 MHz RFQ. The RFQ is based on an unusual beam dynamicsdesign and is capable of operating at a duty factor that produces morethan 1.2 mA timeaverage beam current. The beam is transported to a2-atmosphere deuterium gas target with a specially-designed, thinentrance window. A high-frequency dipole magnet is used to spread thebeam over the long dimension of the 4 by 35 cm target window. The sourcewill be capable of delivering a neutron flux of ~;2 x 107 n/(cm2 x s) tothe center of a sea-land cargo container and is expected t o satisfy therequirements for full testing and demonstration of advanced neutroninterrogation techniques based on stimulated SNM signatures.

  9. Ice-sheet acceleration driven by melt supply variability.

    PubMed

    Schoof, Christian

    2010-12-01

    Increased ice velocities in Greenland are contributing significantly to eustatic sea level rise. Faster ice flow has been associated with ice-ocean interactions in water-terminating outlet glaciers and with increased surface meltwater supply to the ice-sheet bed inland. Observed correlations between surface melt and ice acceleration have raised the possibility of a positive feedback in which surface melting and accelerated dynamic thinning reinforce one another, suggesting that overall warming could lead to accelerated mass loss. Here I show that it is not simply mean surface melt but an increase in water input variability that drives faster ice flow. Glacier sliding responds to melt indirectly through changes in basal water pressure, with observations showing that water under glaciers drains through channels at low pressure or through interconnected cavities at high pressure. Using a model that captures the dynamic switching between channel and cavity drainage modes, I show that channelization and glacier deceleration rather than acceleration occur above a critical rate of water flow. Higher rates of steady water supply can therefore suppress rather than enhance dynamic thinning, indicating that the melt/dynamic thinning feedback is not universally operational. Short-term increases in water input are, however, accommodated by the drainage system through temporary spikes in water pressure. It is these spikes that lead to ice acceleration, which is therefore driven by strong diurnal melt cycles and an increase in rain and surface lake drainage events rather than an increase in mean melt supply.

  10. Design and testing of a DC ion injector suitable for accelerator-driven transmutation

    NASA Astrophysics Data System (ADS)

    Schneider, J. David; Meyer, Earl; Stevens, Ralph R.; Hansborough, Lash; Sherman, Joseph

    1995-09-01

    For a number of years, Los Alamos personnel have collaborated with a team of experimentalists at Chalk River Labs (CRL) near Deep River, Ontario, Canada who were pursuing the development of the front end of a high power cw proton accelerator. At the termination of this program last year, Los Alamos acquired this equipment. With the help of internal Laboratory funding and modest defense conversion funds, we have set up and operated the accelerator at Los Alamos. Operational equipment includes a slightly modified Chalk River Injector Test Stand (CRITS) including a 50 keV proton injector and a 1.25 MeV radio-frequency quadrupole (RFQ) with a klystrode rf power system. Substantial upgrading and modification of the ac power system was necessary to provide the required ac voltage (2400 vac) and power (2 MVA) needed for the operation of this equipment. A companion paper describes in detail the first ion source and beam-transport measurements at Los Alamos. Many of the challenges involved in operating an rf linear accelerator to provide neutrons for an accelerator-driven reactor are encountered at the front (low energy) end of this system. The formation of the ion beam, the control of the beam parameters, and the focusing and matching of a highly space-charge-dominated beam are major problems. To address the operating problems in this critical front end, the Accelerator Operations and Technology Division at the Los Alamos National Laboratory has designed the APDF (Accelerator Prototype Demonstration Facility). The front end of this facility is a 75 keV, high-current, ion injector which has been assembled and is now being tested. This paper discusses the design modifications required in going from the 50 keV CRITS injector to the higher current, 75 keV injector. Major innovative changes were made in the design of this injector. This design eliminates all the control electronics and most of the ion source equipment at high potential. Also, a new, high-quality, ion

  11. Adding PCs to SLC Control System

    SciTech Connect

    Lahey, T.; Levitt, S.; MacKenzie, R.; Spencer, N.; Underwood, K.

    1993-05-01

    The SLAC Controls Department has interfaced IBM-Compatible PCs to the SLC Control System, for use by the Final Focus Test Beam (FFTB) experimenters, who are building new accelerator equipment and developing and testing it at their home institutions. They will bring the equipment to SLAC and integrate it into the control system using a new software package. The machine physicists and operators will use the existing SLC control system applications and database device types to control and monitor the equipment. The PCs support a limited control environment: they run DOS and exchange messages with the existing control system via TCP/IP over ethernet, using the new SLC Area Message Service. This mechanism will also allow SLC to implement other commercial device controllers that can communicate over ethernet and run the same software interface code.

  12. Neutronics of accelerator-driven subcritical fission for burning transuranics in used nuclear fuel

    SciTech Connect

    Sattarov, A.; Assadi, S.; Badgley, K.; Baty, A.; Comeaux, J.; Gerity, J.; Kellams, J.; Mcintyre, P.; Pogue, N.; Sooby, E.; Tsvetkov, P.; Rosaire, G.; Mann, T.

    2013-04-19

    We report the development of a conceptual design for accelerator-driven subcritical fission in a molten salt core (ADSMS). ADSMS is capable of destroying all of the transuranics at the same rate and proportion as they are produced in a conventional nuclear power plant. The ADSMS core is fueled solely by transuranics extracted from used nuclear fuel and reduces its radiotoxicity by a factor 10,000. ADSMS offers a way to close the nuclear fuel cycle so that the full energy potential in the fertile fuels uranium and thorium can be recovered.

  13. Neutronics of accelerator-driven subcritical fission for burning transuranics in used nuclear fuel

    NASA Astrophysics Data System (ADS)

    Sattarov, A.; Assadi, S.; Badgley, K.; Baty, A.; Comeaux, J.; Gerity, J.; Kellams, J.; Mcintyre, P.; Pogue, N.; Sooby, E.; Tsvetkov, P.; Rosaire, G.; Mann, T.

    2013-04-01

    We report the development of a conceptual design for accelerator-driven subcritical fission in a molten salt core (ADSMS). ADSMS is capable of destroying all of the transuranics at the same rate and proportion as they are produced in a conventional nuclear power plant. The ADSMS core is fueled solely by transuranics extracted from used nuclear fuel and reduces its radiotoxicity by a factor 10,000. ADSMS offers a way to close the nuclear fuel cycle so that the full energy potential in the fertile fuels uranium and thorium can be recovered.

  14. Secure ADS-B authentication system and method

    NASA Technical Reports Server (NTRS)

    Viggiano, Marc J (Inventor); Valovage, Edward M (Inventor); Samuelson, Kenneth B (Inventor); Hall, Dana L (Inventor)

    2010-01-01

    A secure system for authenticating the identity of ADS-B systems, including: an authenticator, including a unique id generator and a transmitter transmitting the unique id to one or more ADS-B transmitters; one or more ADS-B transmitters, including a receiver receiving the unique id, one or more secure processing stages merging the unique id with the ADS-B transmitter's identification, data and secret key and generating a secure code identification and a transmitter transmitting a response containing the secure code and ADSB transmitter's data to the authenticator; the authenticator including means for independently determining each ADS-B transmitter's secret key, a receiver receiving each ADS-B transmitter's response, one or more secure processing stages merging the unique id, ADS-B transmitter's identification and data and generating a secure code, and comparison processing comparing the authenticator-generated secure code and the ADS-B transmitter-generated secure code and providing an authentication signal based on the comparison result.

  15. A Secure and Privacy-Preserving Targeted Ad-System

    NASA Astrophysics Data System (ADS)

    Androulaki, Elli; Bellovin, Steven M.

    Thanks to its low product-promotion cost and its efficiency, targeted online advertising has become very popular. Unfortunately, being profile-based, online advertising methods violate consumers' privacy, which has engendered resistance to the ads. However, protecting privacy through anonymity seems to encourage click-fraud. In this paper, we define consumer's privacy and present a privacy-preserving, targeted ad system (PPOAd) which is resistant towards click fraud. Our scheme is structured to provide financial incentives to all entities involved.

  16. Towards the final BSA modeling for the accelerator-driven BNCT facility at INFN LNL.

    PubMed

    Ceballos, C; Esposito, J; Agosteo, S; Colautti, P; Conte, V; Moro, D; Pola, A

    2011-12-01

    Some remarkable advances have been made in the last years on the SPES-BNCT project of the Istituto Nazionale di Fisica Nucleare (INFN) towards the development of the accelerator-driven thermal neutron beam facility at the Legnaro National Laboratories (LNL), aimed at the BNCT experimental treatment of extended skin melanoma. The compact neutron source will be produced via the (9)Be(p,xn) reactions using the 5 MeV, 30 mA beam driven by the RFQ accelerator, whose modules construction has been recently completed, into a thick beryllium target prototype already available. The Beam Shaping Assembly (BSA) final modeling, using both neutron converter and the new, detailed, Be(p,xn) neutron yield spectra at 5 MeV energy recently measured at the CN Van de Graaff accelerator at LNL, is summarized here.

  17. Adding Value to Scholarly Journals through a Citation Indexing System

    ERIC Educational Resources Information Center

    Zainab, A. N.; Abrizah, A.; Raj, R. G.

    2013-01-01

    Purpose: The purpose of this paper is to relate the problems identified about scholarly journal publishing in Malaysia to establish motivation for the system development; to describe the design of MyCite, a Malaysian citation indexing system and to highlight the added value to journals and articles indexed through the generation of bibliometrics…

  18. An Online Satellite Altimetry Data Processing System: Ads Central

    NASA Astrophysics Data System (ADS)

    Helm, A.; Braun, A.; Schöne, T.; Wen, H.; Reigber, C.

    To help solving important issues of climate change and sea level change and to un- derstand the complex system Earth, an interdisciplinary interpretation of various data sets is needed. Several groups on the national and international level are recently ac- tive in building up services to faciliate the access to geoscientific data to a broader community, especially the access to higher level products. In Germany, GFZ-Potsdam is currently building up the modular German Earth Science and Information System (GESIS). In the frame of GESIS the Altimeter Database System (ADS) has been com- pleted recently. This modul provides high quality data and processing capabilities for radar altimetry data to a wide range of users. The ADS modul can be accessed worldwide via the internet based user-interface "ADS Central" with a standard browser at (http://gesis.gfz-potsdam.de/ads). After a registra- tion process the system offers higher level standard products, calculated routinely from the harmonised and intercalibrated satellite database. Additionally, ADS allows to generate individual user specific products. The user is able to perform several processing and analysing steps, e.g. to generate mean sea sur- face height grids, to extract altimetry data time series around a given location, to anal- yse parameter variability, or to perform a crossover analysis. The user can specify general parameters like the satellite mission, time interval and region of the used data. Additionally, different available correction models can be choosen, which will be ap- plied to the data. It is further possible to enter several quality parameters to optimize the data for individual applications. These individual user defined products are au- tomatically processed by ADS at GFZ-Potsdam and are subsequently distributed via anonymous ftp. The system is an attempt to offer easy access to the daily growing satellite altime- try database and numerous correction models and orbits. Due to the effectiveness

  19. Multimodal Geographic Information Systems: Adding Haptic and Auditory Display.

    ERIC Educational Resources Information Center

    Jeong, Wooseob; Gluck, Myke

    2003-01-01

    Investigated the feasibility of adding haptic and auditory displays to traditional visual geographic information systems (GISs). Explored differences in user performance, including task completion time and accuracy, and user satisfaction with a multimodal GIS which was implemented with a haptic display, auditory display, and combined display.…

  20. Direct numerical simulation of incompressible acceleration-driven variable-density turbulence

    NASA Astrophysics Data System (ADS)

    Gat, Ilana; Matheou, Georgios; Chung, Daniel; Dimotakis, Paul

    2015-11-01

    Fully developed turbulence in variable-density flow driven by an externally imposed acceleration field, e.g., gravity, is fundamental in many applications, such as inertial confinement fusion, geophysics, and astrophysics. Aspects of this turbulence regime are poorly understood and are of interest to fluid modeling. We investigate incompressible acceleration-driven variable-density turbulence by a series of direct numerical simulations of high-density fluid in-between slabs of low-density fluid, in a triply-periodic domain. A pseudo-spectral numerical method with a Helmholtz-Hodge decomposition of the pressure field, which ensures mass conservation, is employed, as documented in Chung & Pullin (2010). A uniform dynamic viscosity and local Schmidt number of unity are assumed. This configuration encapsulates a combination of flow phenomena in a temporally evolving variable-density shear flow. Density ratios up to 10 and Reynolds numbers in the fully developed turbulent regime are investigated. The temporal evolution of the vertical velocity difference across the shear layer, shear-layer growth, mean density, and Reynolds number are discussed. Statistics of Lagrangian accelerations of fluid elements and of vorticity as a function of the density ratio are also presented. This material is based upon work supported by the AFOSR, the DOE, the NSF GRFP, and Caltech.

  1. Burn-up and neutron economy of accelerator-driven reactor

    SciTech Connect

    Takahashi, H.; Yang, W.; An, Y.; Yamazaki, Y.

    1997-07-01

    It is desirable to have only a small reactivity change in the large burn-up of a solid fuel fast reactor, so that the number of replacements or shuffling of the fuel can be reduced, and plant factor accordingly increased. Also, this reduces the number of control rods needed for the change in burn-up reactivity. In subcritical operation, power controlled by beam power is suggested, but this practice is not as economical as the use of control rods and makes more careful operation of the accelerator is required due to changes in the wake field. In subcritical operation, even a slightly subcritical one, the safety problems associated with a hard neutron spectrum can be alleviated. Neutron leakage from a flattened core, which is needed for operation of the critical fast reactor can be lessen by using the non flat core which has good neutron economy. For generating nuclear energy, it is essential to have a high neutron economy, although breeding the fuel is not welcomed in the present political climate, as is needed for transmuting long lived fission products. In contrast to the breeder, the accelerator driven reactor can separate the energy production from fuel production and processing. Thus, it is suited for non-proliferation of nuclear material by prohibiting the processing and production of fuel in the unrestricted area so this can be only done in international controlled areas which are restricted and remote.

  2. Radiation effects in materials for accelerator-driven neutron technologies. Revision

    SciTech Connect

    Wechsler, M.S.; Lin, C.; Sommer, W.F.

    1997-04-01

    Accelerator-driven neutron technologies use spallation neutron sources (SNS`s) in which high-energy protons bombard a heavy-element target and spallation neutrons are produced. The materials exposed to the most damaging radiation environments in an SNS are those in the path of the incident proton beam. This includes target and window materials. These materials will experience damage from the incident protons and the spallation neutrons. In addition, some materials will be damaged by the spallation neutrons alone. The principal materials of interest for SNS`s are discussed elsewhere. The target should consist of one or more heavy elements, so as to increase the number of neutrons produced per incident proton. A liquid metal target (e.g., Pb, Bi, Pb-Bi, Pb-Mg, and Hg) has the advantage of eliminating the effects of radiation damage on the target material itself, but concerns over corrosion problems and the influence of transmutants remain. The major solid targets in operating SNS`s and under consideration for the 1-5 MW SNS`s are W, U, and Pb. Tungsten is the target material at LANSCE, and is the projected target material for an upgraded LANSCE target that is presently being designed. It is also the projected target material for the tritium producing SNS under design at LANL. In this paper, the authors present the results of spallation radiation damage calculations (displacement and He production) for tungsten.

  3. The Grid Analysis and Display System (GrADS)

    NASA Technical Reports Server (NTRS)

    Kinter, James L., III

    1994-01-01

    During the period 1 September 1993 - 31 August 1994, further development of the Grid Analysis and Display System (GrADS) was conducted at the Center for Ocean-Land-Atmosphere Studies (COLA) of the Institute of Global Environment and Society, Inc. (IGES) under subcontract 5555-31 from the University Space Research Association (USRA) administered by The Center of Excellence in Space Data and Information Sciences (CESDIS). This final report documents progress made under this subcontract and provides directions on how to access the software and documentation developed therein. A short description of GrADS is provided followed by summary of progress completed and a summary of the distribution of the software to date and the establishment of research collaborations.

  4. Accelerator-driven destruction of long-lived radioactive waste and energy production

    SciTech Connect

    Schriber, S.O.

    1997-12-31

    Nuclear waste management involves many issues. ATW is an option that can assist a repository by enhancing its capability and thereby assist nuclear waste management. Technology advances and the recent release of liquid metal coolant information from Russia has had an enormous impact on the viability of an ATW system. It now appears economic with many repository enhancing attributes. In time, an ATW option added to present repository activities will provide the public with a nuclear fuel cycle that is acceptable from economic and environmental points of view.

  5. Asynchronous ad hoc network discovery for low-power systems

    NASA Astrophysics Data System (ADS)

    Joslin, Todd W.

    2008-04-01

    Unattended ground sensor systems (UGS) have become an important part of a covert monitoring arsenal in operations throughout the world. With the increased use of unattended ground sensor systems, there is a need to develop communication architectures that allow the systems to have simple emplacement procedures, have a long mission life, and be difficult to detect. Current ad-hoc networking schemes use either a network beacon, extensive preambles, or guaranteed time synchronization to achieve reliable communications. When used in wireless sensor systems many of these schemes waste power through unnecessary transmissions. These schemes compromise the covert nature of UGS through excess transmissions for a non-beaconed network or the periodic beaconing in a beaconed network. These factors are detrimental to sensor systems, which chiefly rely on being covert and low-power. This paper discusses a nonarbitrated, non-GPS synchronized, beaconless approach to discovering, joining, and reliably transmitting and receiving in a low-power ad-hoc wireless sensor network. This solution is capable of performing network discovery upon demand to get an initial alignment with other nodes in the network. Once aligned, end points maintain alignment and can predict when other nodes will be available to listen.

  6. Indoor Positioning - An Ad-Hoc Positioning System

    NASA Astrophysics Data System (ADS)

    Mautz, Rainer

    2008-06-01

    The aim of this paper is to discuss the development of an automatic, low-cost system that exploits current or near future wireless communications technology to enable continuous tracking of the location of devices in all environments. The development of such a wireless sensor network involves system design, digital signal processing, protocol development, extraction of ranges and localisation. This paper focuses on the user requirements, system architecture and network positioning. The user requirements are presented with a focus on applications in geodesy. A high level strategy for the positioning function is presented based on an ad-hoc geodetic network positioning method including issues of accuracy, quality and reliability of the node positions. Results show that it is possible to achieve a position deviation that is of the size of the ranging error.

  7. Effect of the transverse parasitic mode on beam performance for the ADS driver linac in China

    NASA Astrophysics Data System (ADS)

    Cheng, Peng; Pei, Shi-Lun; Wang, Jiu-Qing; Li, Zhi-Hui

    2015-05-01

    The ADS (Accelerator Driven subcritical System) driver linac in China is designed to run in CW (Continuous Wave) mode with 10 mA designed beam current. In this scenario, the beam-induced parasitic modes in the ADS driver linac may make the beam unstable or deteriorate the beam performance. To evaluate the parasitic mode effect on the beam dynamics systematically, simulation studies using the ROOT-based numerical code SMD have been conducted. The longitudinal beam instability induced by the HOMs (High Order Modes) and SOMs (Same Order Modes) has little effect on the longitudinal beam performance for the current ADS driver linac design based on the 10 MeV/325 MHz injector I from previous studies. Here the transverse parasitic mode (i.e., dipole HOM) effect on the transverse beam performance at the ADS driver linac exit is investigated. To more reasonably quantify the dipole mode effect, the multi-bunch effective emittance is introduced in this paper.

  8. Properties of the Feynman-alpha method applied to accelerator-driven subcritical systems.

    PubMed

    Taczanowski, S; Domanska, G; Kopec, M; Janczyszyn, J

    2005-01-01

    A Monte Carlo study of the Feynman-method with a simple code simulating the multiplication chain, confined to pertinent time-dependent phenomena has been done. The significance of its key parameters (detector efficiency and dead time, k-source and spallation neutrons multiplicities, required number of fissions etc.) has been discussed. It has been demonstrated that this method can be insensitive to properties of the zones surrounding the core, whereas is strongly affected by the detector dead time. In turn, the influence of harmonics in the neutron field and of the dispersion of spallation neutrons has proven much less pronounced.

  9. Accelerator driven system based on plutonium subcritical reactor and 660 MeV phasotron

    NASA Astrophysics Data System (ADS)

    Arkhipov, V. A.; Barashenkov, V. S.; Buttsev, V. S.; Chultem, D.; Dudarev, S. Yu.; Furman, V. I.; Gudowski, W.; Janczyszyn, J.; Maltsev, A. A.; Onischenko, L. M.; Pogodajev, G. N.; Polanski, A.; Popov, Yu. P.; Puzynin, I. V.; Sissakian, A. N.; Taczanowski, S.

    1999-11-01

    The proposal presents a PLUTONIUM BASED ENERGY AMPLIFIER TESTING CONCEPT which employs a plutonium subcritical assembly and a 660 MeV proton accelerator, operating in the the JINR (Dubna, Russia). To make the present conceptual design of the Plutonium Energy Amplifier we have chosen a nominal unit capacity of 20 kW (thermal). This corresponds to the multiplication coefficient keff between 0.94 and 0.95 and the energetic gain about 20.

  10. YALINA analytical benchmark analyses using the deterministic ERANOS code system.

    SciTech Connect

    Gohar, Y.; Aliberti, G.; Nuclear Engineering Division

    2009-08-31

    The growing stockpile of nuclear waste constitutes a severe challenge for the mankind for more than hundred thousand years. To reduce the radiotoxicity of the nuclear waste, the Accelerator Driven System (ADS) has been proposed. One of the most important issues of ADSs technology is the choice of the appropriate neutron spectrum for the transmutation of Minor Actinides (MA) and Long Lived Fission Products (LLFP). This report presents the analytical analyses obtained with the deterministic ERANOS code system for the YALINA facility within: (a) the collaboration between Argonne National Laboratory (ANL) of USA and the Joint Institute for Power and Nuclear Research (JIPNR) Sosny of Belarus; and (b) the IAEA coordinated research projects for accelerator driven systems (ADS). This activity is conducted as a part of the Russian Research Reactor Fuel Return (RRRFR) Program and the Global Threat Reduction Initiative (GTRI) of DOE/NNSA.

  11. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    NASA Astrophysics Data System (ADS)

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Phongikaroon, Supathorn; Sattarov, Akhdiyor; Simpson, Michael; Sooby, Elizabeth; Tsvetkov, Pavel

    2013-04-01

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  12. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    SciTech Connect

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Sattarov, Akhdiyor; Sooby, Elizabeth; Tsvetkov, Pavel; Phongikaroon, Supathorn; Simpson, Michael

    2013-04-19

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  13. Sensitivity and Uncertainty Analysis to Burnup Estimates on ADS using the ACAB Code

    NASA Astrophysics Data System (ADS)

    Cabellos, O.; Sanz, J.; Rodríguez, A.; González, E.; Embid, M.; Alvarez, F.; Reyes, S.

    2005-05-01

    Within the scope of the Accelerator Driven System (ADS) concept for nuclear waste management applications, the burnup uncertainty estimates due to uncertainty in the activation cross sections (XSs) are important regarding both the safety and the efficiency of the waste burning process. We have applied both sensitivity analysis and Monte Carlo methodology to actinides burnup calculations in a lead-bismuth cooled subcritical ADS. The sensitivity analysis is used to identify the reaction XSs and the dominant chains that contribute most significantly to the uncertainty. The Monte Carlo methodology gives the burnup uncertainty estimates due to the synergetic/global effect of the complete set of XS uncertainties. These uncertainty estimates are valuable to assess the need of any experimental or systematic re-evaluation of some uncertainty XSs for ADS.

  14. Sensitivity and Uncertainty Analysis to Burn-up Estimates on ADS Using ACAB Code

    SciTech Connect

    Cabellos, O; Sanz, J; Rodriguez, A; Gonzalez, E; Embid, M; Alvarez, F; Reyes, S

    2005-02-11

    Within the scope of the Accelerator Driven System (ADS) concept for nuclear waste management applications, the burnup uncertainty estimates due to uncertainty in the activation cross sections (XSs) are important regarding both the safety and the efficiency of the waste burning process. We have applied both sensitivity analysis and Monte Carlo methodology to actinides burnup calculations in a lead-bismuth cooled subcritical ADS. The sensitivity analysis is used to identify the reaction XSs and the dominant chains that contribute most significantly to the uncertainty. The Monte Carlo methodology gives the burnup uncertainty estimates due to the synergetic/global effect of the complete set of XS uncertainties. These uncertainty estimates are valuable to assess the need of any experimental or systematic reevaluation of some uncertainty XSs for ADS.

  15. Sensitivity and Uncertainty Analysis to Burnup Estimates on ADS using the ACAB Code

    SciTech Connect

    Cabellos, O.; Sanz, J.; Rodriguez, A.; Gonzalez, E.; Embid, M.; Alvarez, F.; Reyes, S.

    2005-05-24

    Within the scope of the Accelerator Driven System (ADS) concept for nuclear waste management applications, the burnup uncertainty estimates due to uncertainty in the activation cross sections (XSs) are important regarding both the safety and the efficiency of the waste burning process. We have applied both sensitivity analysis and Monte Carlo methodology to actinides burnup calculations in a lead-bismuth cooled subcritical ADS. The sensitivity analysis is used to identify the reaction XSs and the dominant chains that contribute most significantly to the uncertainty. The Monte Carlo methodology gives the burnup uncertainty estimates due to the synergetic/global effect of the complete set of XS uncertainties. These uncertainty estimates are valuable to assess the need of any experimental or systematic re-evaluation of some uncertainty XSs for ADS.

  16. Design of the new couplers for C-ADS RFQ

    NASA Astrophysics Data System (ADS)

    Shi, Ai-Min; Sun, Lie-Peng; Zhang, Zhou-Li; Xu, Xian-Bo; Shi, Long-Bo; Li, Chen-Xing; Wang, Wen-Bin

    2015-04-01

    A new special coupler with a kind of bowl-shaped ceramic window for a proton linear accelerator named the Chinese Accelerator Driven System (C-ADS) at the Institute of Modern Physics (IMP) has been simulated and constructed and a continuous wave (CW) beam commissioning through a four-meter long radio frequency quadruple (RFQ) was completed by the end of July 2014. In the experiments of conditioning and beam, some problems were promoted gradually such as sparking and thermal issues. Finally, two new couplers were passed with almost 110 kW CW power and 120 kW pulsed mode, respectively. The 10 mA intensity beam experiments have now been completed, and the couplers during the operation had no thermal or electro-magnetic problems. The detailed design and results are presented in the paper. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03020500)

  17. Grid Analysis and Display System (GrADS): A practical tool for earth science visualization

    NASA Technical Reports Server (NTRS)

    Kinter, James L., III; Doty, Brian E.

    1991-01-01

    Viewgraphs on grid analysis and display system (GrADS): a practical tool for earth science visualization are presented. Topics covered include: GrADS design goals; data sets; and temperature profiles.

  18. Theoretical and experimental evaluation of the windowless interface for the TRASCO-ADS project

    NASA Astrophysics Data System (ADS)

    Michelato, P.; Bari, E.; Monaco, L.; Sertore, D.; Bonucci, A.; Giannantonio, R.; Urbano, M.; Viale, L.; Turroni, P.; Cinotti, L.

    2004-07-01

    TRASCO-ADS is a national funded program in which INFN, ENEA, and Italian industries work on the design of an accelerator driven subcritical system for nuclear waste transmutation. TRASCO is the Italian acronym for Transmutation (TRAsmutazione) of Waste (SCOrie). One of the most critical aspects in the design of an Accelerator Driven System is related to the interface region, which is the part of the beamline located between the accelerator, operating under UHV conditions, and the pressurized reactor vessel, consisting of a contained plenum of Pb-Bi eutectic (LBE). A so-called window could separate these two environments, but thermomechanical considerations and radioprotection issues point out that this component could be critical. In the windowless interface, no window is located between the linac and the spallation target. Only a suitable pumping and trapping system, for the gases and the vapors outcoming from LBE, divides the UHV accelerator and the spallation target vacuum. Vacuum gas dynamics theoretical considerations and calculations are presented in this article. The need for a validation of the theoretical models gave the motivation for an experimental work, whose results are also discussed. Scale-up of the experimental setup to the full system needs accurate analyses for a proper dimensioning of the system in the interface region. .

  19. Perfect fluidity of a dissipative system: Analytical solution for the Boltzmann equation in AdS2 Ⓧ S2

    DOE PAGES

    Noronha, Jorge; Denicol, Gabriel S.

    2015-12-30

    In this paper we obtain an analytical solution of the relativistic Boltzmann equation under the relaxation time approximation that describes the out-of-equilibrium dynamics of a radially expanding massless gas. This solution is found by mapping this expanding system in flat spacetime to a static flow in the curved spacetime AdS2 Ⓧ S2. We further derive explicit analytic expressions for the momentum dependence of the single-particle distribution function as well as for the spatial dependence of its moments. We find that this dissipative system has the ability to flow as a perfect fluid even though its entropy density does not matchmore » the equilibrium form. The nonequilibrium contribution to the entropy density is shown to be due to higher-order scalar moments (which possess no hydrodynamical interpretation) of the Boltzmann equation that can remain out of equilibrium but do not couple to the energy-momentum tensor of the system. Furthermore, in this system the slowly moving hydrodynamic degrees of freedom can exhibit true perfect fluidity while being totally decoupled from the fast moving, nonhydrodynamical microscopic degrees of freedom that lead to entropy production.« less

  20. Accelerator-driven transmutation of high-level waste from the defense and commercial sectors

    SciTech Connect

    Bowman, C.; Arthur, E.; Beard, C.

    1996-09-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The major goal has been to develop accelerator transmutation of waste (ATW) system designs that will thoroughly and rapidly transmute nuclear waste, including plutonium from dismantled weapons and spent reactor fuel, while generating useful electrical power and without producing a long-lived radioactive waste stream. We have identified and quantified the unique qualities of subcritical nuclear systems and their capabilities in bringing about the complete destruction of plutonium. Although the 1191 subcritical systems involved in our most effective designs radically depart from traditional nuclear reactor concepts, they are based on extrapolations of existing technologies. Overall, care was taken to retain the highly desired features that nuclear technology has developed over the years within a conservative design envelope. We believe that the ATW systems designed in this project will enable almost complete destruction of nuclear waste (conversion to stable species) at a faster rate and without many of the safety concerns associated with the possible reactor approaches.

  1. Space Moves: Adding Movement to Solar System Lessons

    ERIC Educational Resources Information Center

    Jenkins, Deborah Bainer; Heidorn, Brent

    2009-01-01

    Earth and space science figure prominently in the National Science Education Standards for levels 5-8 (NRC 1996). The Earth in the Solar System standard focuses on students' ability to understand (1) the composition of the solar system (Earth, Moon, Sun, planets with their moons, and smaller objects like asteroids and comets) and (2) that…

  2. Method for adding nodes to a quantum key distribution system

    DOEpatents

    Grice, Warren P

    2015-02-24

    An improved quantum key distribution (QKD) system and method are provided. The system and method introduce new clients at intermediate points along a quantum channel, where any two clients can establish a secret key without the need for a secret meeting between the clients. The new clients perform operations on photons as they pass through nodes in the quantum channel, and participate in a non-secret protocol that is amended to include the new clients. The system and method significantly increase the number of clients that can be supported by a conventional QKD system, with only a modest increase in cost. The system and method are compatible with a variety of QKD schemes, including polarization, time-bin, continuous variable and entanglement QKD.

  3. High-energy in-beam neutron measurements of metal-based shielding for accelerator-driven spallation neutron sources

    NASA Astrophysics Data System (ADS)

    DiJulio, D. D.; Cooper-Jensen, C. P.; Björgvinsdóttir, H.; Kokai, Z.; Bentley, P. M.

    2016-05-01

    Metal-based shielding plays an important role in the attenuation of harmful and unwanted radiation at an accelerator-driven spallation neutron source. At the European Spallation Source, currently under construction in Lund, Sweden, metal-based materials are planned to be used extensively as neutron guide substrates in addition to other shielding structures around neutron guides. The usage of metal-based materials in the vicinity of neutron guides however requires careful consideration in order to minimize potential background effects in a neutron instrument at the facility. Therefore, we have carried out a combined study involving high-energy neutron measurements and Monte Carlo simulations of metal-based shielding, both to validate the simulation methodology and also to investigate the benefits and drawbacks of different metal-based solutions. The measurements were carried out at The Svedberg Laboratory in Uppsala, Sweden, using a 174.1 MeV neutron beam and various thicknesses of aluminum-, iron-, and copper-based shielding blocks. The results were compared to geant4 simulations and revealed excellent agreement. Our combined study highlights the particular situations where one type of metal-based solution may be preferred over another.

  4. Mechanical Design and Analysis of a 200 MHz, Bolt-together RFQ forthe Accelerator Driven Neutron Source

    SciTech Connect

    Virostek, Steve; Hoff, Matt; Li, Derun; Staples, John; Wells,Russell

    2007-06-20

    A high-yield neutron source to screen sea-land cargocontainers for shielded Special Nuclear Materials (SNM) has been designedat LBNL [1,2]. The Accelerator-Driven Neutron Source (ADNS) uses theD(d,n)3He reaction to create a forward directed neutron beam. Keycomponents are a high-current radio-frequency quadrupole (RFQ)accelerator and a high-power target capable of producing a neutron fluxof>107 n/(cm2 cdot s) at a distance of 2.5 m. The mechanical designand analysis of the four-module, bolt-together RFQ will be presentedhere. Operating at 200 MHz, the 5.1 m long RFQ will accelerate a 40 mAdeuteron beam to 6 MeV. At a 5 percent duty factor, the time-average d+beam current on target is 1.5 mA. Each of the 1.27 m long RFQ moduleswill consist of four solid OFHC copper vanes. A specially designed 3-DO-ring will provide vacuum sealing between both the vanes and themodules. RF connections are made with canted coil spring contacts. Aseries of 60 water-cooled pi-mode rods provides quadrupole modestabilization. A set of 80 evenly spaced fixed slug tuners is used forfinal frequency adjustment and local field perturbationcorrection.

  5. Nuclear modeling for applications in medical radiation therapy and accelerator-driven technologies

    SciTech Connect

    Chadwick, M.B.

    1995-06-01

    An understanding of the interactions of neutrons and protons below a few hundred MeV with nuclei is important for a number of applications. In this paper, two new applications are discussed: radiation transport calculations of energy deposition in fast neutron and proton cancer radiotherapy to optimize the dose given to a tumor; and intermediate-energy proton accelerators which are currently being designed for a range of applications including the destruction of long-lived radioactive nuclear waste. We describe nuclear theory calculations of direct, preequilibrium, and compound nucleus reaction mechanisms important for the modeling of these systems.

  6. Supporting health systems in Europe: added value of EU actions?

    PubMed

    Clemens, Timo; Michelsen, Kai; Brand, Helmut

    2014-01-01

    Since the start of the economic crisis, the European Union's (EU's) predominant discourse has been austerity and fiscal consolidation. The detrimental effects on Europe's health systems and the health status of its citizens are well described. However, little is known about the emerging EU-level initiatives to support national health systems handle the challenges of efficient care provision and system reorganisation aimed to meet their future needs. This review analyses the manner, conditions and prospects of such EU support. First, health system objectives are increasingly entering the EU health policy agenda. Second, professional and patient mobility provisions may support member states (MS) in copying with crisis related health challenges but can potentially acerbate them at the same time. Third, in recent initiatives health system goals are more closely tied to the EU's economic growth narrative. And fourth, health system issues are taken up in existing EU-level structures for debate and exchange between MS. In addition, the design of some policies may have the potential to intensify socioeconomic and health inequalities rather than ameliorate them.

  7. Adding Data Management Services to Parallel File Systems

    SciTech Connect

    Brandt, Scott

    2015-03-04

    The objective of this project, called DAMASC for “Data Management in Scientific Computing”, is to coalesce data management with parallel file system management to present a declarative interface to scientists for managing, querying, and analyzing extremely large data sets efficiently and predictably. Managing extremely large data sets is a key challenge of exascale computing. The overhead, energy, and cost of moving massive volumes of data demand designs where computation is close to storage. In current architectures, compute/analysis clusters access data in a physically separate parallel file system and largely leave it scientist to reduce data movement. Over the past decades the high-end computing community has adopted middleware with multiple layers of abstractions and specialized file formats such as NetCDF-4 and HDF5. These abstractions provide a limited set of high-level data processing functions, but have inherent functionality and performance limitations: middleware that provides access to the highly structured contents of scientific data files stored in the (unstructured) file systems can only optimize to the extent that file system interfaces permit; the highly structured formats of these files often impedes native file system performance optimizations. We are developing Damasc, an enhanced high-performance file system with native rich data management services. Damasc will enable efficient queries and updates over files stored in their native byte-stream format while retaining the inherent performance of file system data storage via declarative queries and updates over views of underlying files. Damasc has four key benefits for the development of data-intensive scientific code: (1) applications can use important data-management services, such as declarative queries, views, and provenance tracking, that are currently available only within database systems; (2) the use of these services becomes easier, as they are provided within a familiar file

  8. New Compressor Added to Glenn's 450- psig Combustion Air System

    NASA Technical Reports Server (NTRS)

    Swan, Jeffrey A.

    2000-01-01

    In September 1999, the Central Process Systems Engineering Branch and the Maintenance and the Central Process Systems Operations Branch, released for service a new high pressure compressor to supplement the 450-psig Combustion Air System at the NASA Glenn Research Center at Lewis Field. The new compressor, designated C-18, is located in Glenn s Central Air Equipment Building and is remotely operated from the Central Control Building. C-18 can provide 40 pounds per second (pps) of airflow at pressure to our research customers. This capability augments our existing system capacity (compressors C 4 at 38 pps and C-5 at 32 pps), which is generated from Glenn's Engine Research Building. The C-18 compressor was originally part of Glenn's 21-Inch Hypersonic Tunnel, which was transferred from the Jet Propulsion Laboratory to Glenn in the mid-1980's. With the investment of construction of facilities funding, the compressor was modified, new mechanical and electrical support equipment were purchased, and the unit was installed in the basement of the Central Air Equipment Building. After several weeks of checkout and troubleshooting, the new compressor was ready for long-term, reliable operations. With a total of 110 pps in airflow now available, Glenn is well positioned to support the high-pressure air test requirements of our research customers.

  9. Adding intelligent services to an object oriented system

    NASA Technical Reports Server (NTRS)

    Robideaux, Bret R.; Metzler, Theodore A.

    1994-01-01

    As today's software becomes increasingly complex, the need grows for intelligence of one sort or another to becomes part of the application, often an intelligence that does not readily fit the paradigm of one's software development. There are many methods of developing software, but at this time, the most promising is the object oriented (OO) method. This method involves an analysis to abstract the problem into separate 'objects' that are unique in the data that describe them and the behavior that they exhibit, and eventually to convert this analysis into computer code using a programming language that was designed (or retrofitted) for OO implementation. This paper discusses the creation of three different applications that are analyzed, designed, and programmed using the Shlaer/Mellor method of OO development and C++ as the programming language. All three, however, require the use of an expert system to provide an intelligence that C++ (or any other 'traditional' language) is not directly suited to supply. The flexibility of CLIPS permitted us to make modifications to it that allow seamless integration with any of our applications that require an expert system. We illustrate this integration with the following applications: (1) an after action review (AAR) station that assists a reviewer in watching a simulated tank battle and developing an AAR to critique the performance of the participants in the battle; (2) an embedded training system and over-the-shoulder coach for howitzer crewmen; and (3) a system to identify various chemical compounds from their infrared absorption spectra.

  10. Multimodal Geographic Information Systems: Adding Haptic and Auditory Displays.

    ERIC Educational Resources Information Center

    Jeong, Wooseob

    2001-01-01

    This study consists of two experiments. Pitch, volume, and tempo in auditory-haptic geographic information systems were compared in terms of effectiveness for multimodal interface; volume was determined to be better. Auditory display with volume and haptic display with vibration were compared and the results showed that, in more complex geographic…

  11. Periodic orbits of hybrid systems and parameter estimation via AD.

    SciTech Connect

    Guckenheimer, John.; Phipps, Eric Todd; Casey, Richard

    2004-07-01

    Rhythmic, periodic processes are ubiquitous in biological systems; for example, the heart beat, walking, circadian rhythms and the menstrual cycle. Modeling these processes with high fidelity as periodic orbits of dynamical systems is challenging because: (1) (most) nonlinear differential equations can only be solved numerically; (2) accurate computation requires solving boundary value problems; (3) many problems and solutions are only piecewise smooth; (4) many problems require solving differential-algebraic equations; (5) sensitivity information for parameter dependence of solutions requires solving variational equations; and (6) truncation errors in numerical integration degrade performance of optimization methods for parameter estimation. In addition, mathematical models of biological processes frequently contain many poorly-known parameters, and the problems associated with this impedes the construction of detailed, high-fidelity models. Modelers are often faced with the difficult problem of using simulations of a nonlinear model, with complex dynamics and many parameters, to match experimental data. Improved computational tools for exploring parameter space and fitting models to data are clearly needed. This paper describes techniques for computing periodic orbits in systems of hybrid differential-algebraic equations and parameter estimation methods for fitting these orbits to data. These techniques make extensive use of automatic differentiation to accurately and efficiently evaluate derivatives for time integration, parameter sensitivities, root finding and optimization. The boundary value problem representing a periodic orbit in a hybrid system of differential algebraic equations is discretized via multiple-shooting using a high-degree Taylor series integration method [GM00, Phi03]. Numerical solutions to the shooting equations are then estimated by a Newton process yielding an approximate periodic orbit. A metric is defined for computing the distance

  12. Spacecraft Testing Programs: Adding Value to the Systems Engineering Process

    NASA Technical Reports Server (NTRS)

    Britton, Keith J.; Schaible, Dawn M.

    2011-01-01

    Testing has long been recognized as a critical component of spacecraft development activities - yet many major systems failures may have been prevented with more rigorous testing programs. The question is why is more testing not being conducted? Given unlimited resources, more testing would likely be included in a spacecraft development program. Striking the right balance between too much testing and not enough has been a long-term challenge for many industries. The objective of this paper is to discuss some of the barriers, enablers, and best practices for developing and sustaining a strong test program and testing team. This paper will also explore the testing decision factors used by managers; the varying attitudes toward testing; methods to develop strong test engineers; and the influence of behavior, culture and processes on testing programs. KEY WORDS: Risk, Integration and Test, Validation, Verification, Test Program Development

  13. System for adding sulfur to a fuel cell stack system for improved fuel cell stability

    DOEpatents

    Mukerjee, Subhasish; Haltiner, Jr., Karl J; Weissman, Jeffrey G

    2013-08-13

    A system for adding sulfur to a reformate stream feeding a fuel cell stack, having a sulfur source for providing sulfur to the reformate stream and a metering device in fluid connection with the sulfur source and the reformate stream. The metering device injects sulfur from the sulfur source to the reformate stream at a predetermined rate, thereby providing a conditioned reformate stream to the fuel cell stack. The system provides a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.

  14. CYBERSECURITY AND USER ACCOUNTABILITY IN THE C-AD CONTROL SYSTEM

    SciTech Connect

    MORRIS,J.T.; BINELLO, S.; D OTTAVIO, T.; KATZ, R.A.

    2007-10-15

    A heightened awareness of cybersecurity has led to a review of the procedures that ensure user accountability for actions performed on the computers of the Collider-Accelerator Department (C-AD) Control System. Control system consoles are shared by multiple users in control rooms throughout the C-AD complex. A significant challenge has been the establishment of procedures that securely control and monitor access to these shared consoles without impeding accelerator operations. This paper provides an overview of C-AD cybersecurity strategies with an emphasis on recent enhancements in user authentication and tracking methods.

  15. A new method for compensation and rematch of cavity failure in the C-ADS linac

    NASA Astrophysics Data System (ADS)

    Xue, Zhou; Dai, Jian-Ping; Meng, Cai

    2016-06-01

    For proton linear accelerators used in applications such as accelerator-driven systems, due to the nature of the operation, it is essential for the beam failure rate to be several orders of magnitude lower than usual performance of similar accelerators. A fault-tolerant mechanism should be mandatorily imposed in order to maintain short recovery time, high uptime and extremely low frequency of beam loss. This paper proposes an innovative and challenging way for compensation and rematch of cavity failure using fast electronic devices and Field Programmable Gate Arrays (FPGAs) instead of embedded computers to complete the computation of beam dynamics. A method of building an equivalent model for the FPGA, with optimization using a genetic algorithm, is shown. Results based on the model and algorithm are compared with TRACEWIN simulation to show the precision and correctness of the mechanism. Supported by China ADS Project (XDA03020600) and Natural Science Foundation of China (11575216)

  16. Noninterceptive transverse emittance measurements using BPM for Chinese ADS R&D project

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Jun; Feng, Chi; He, Yuan; Dou, Weiping; Tao, Yue; Chen, Wei-long; Jia, Huan; Liu, Shu-hui; Wang, Wang-sheng; Zhang, Yong; Wu, Jian-qiang; Zhang, Sheng-hu; Zhang, X. L.

    2016-04-01

    The noninterceptive four-dimensional transverse emittance measurements are essential for commissioning the high power continue-wave (CW) proton linacs as well as their operations. The conventional emittance measuring devices such as slits and wire scanners are not well suited under these conditions due to sure beam damages. Therefore, the method of using noninterceptive Beam Position Monitor (BPM) is developed and demonstrated on Injector Scheme II at the Chinese Accelerator Driven Sub-critical System (China-ADS) proofing facility inside Institute of Modern Physics (IMP) [1]. The results of measurements are in good agreements with wire scanners and slits at low duty-factor pulsed (LDFP) beam. In this paper, the detailed experiment designs, data analysis and result benchmarking are presented.

  17. Cholinotrophic basal forebrain system alterations in 3xTg-AD transgenic mice.

    PubMed

    Perez, Sylvia E; He, Bin; Muhammad, Nadeem; Oh, Kwang-Jin; Fahnestock, Margaret; Ikonomovic, Milos D; Mufson, Elliott J

    2011-02-01

    The cholinotrophic system, which is dependent upon nerve growth factor and its receptors for survival, is selectively vulnerable in Alzheimer's disease (AD). But, virtually nothing is known about how this deficit develops in relation to the hallmark lesions of this disease, amyloid plaques and tau containing neurofibrillary tangles. The vast majority of transgenic models of AD used to evaluate the effect of beta amyloid (Aβ) deposition upon the cholinotrophic system over-express the amyloid precursor protein (APP). However, nothing is known about how this system is affected in triple transgenic (3xTg)-AD mice, an AD animal model displaying Aβ plaque- and tangle-like pathology in the cortex and hippocampus, which receive extensive cholinergic innervation. We performed a detailed morphological and biochemical characterization of the cholinotrophic system in young (2-4 months), middle-aged (13-15 months) and old (18-20 months) 3xTg-AD mice. Cholinergic neuritic swellings increased in number and size with age, and were more conspicuous in the hippocampal-subicular complex in aged female than in 3xTg-AD male mice. Stereological analysis revealed a reduction in choline acetyltransferase (ChAT) positive cells in the medial septum/vertical limb of the diagonal band of Broca in aged 3xTg-AD mice. ChAT enzyme activity levels decreased significantly in the hippocampus of middle-aged 3xTg-AD mice compared to age-matched non-transgenic (or wild type) mice. ProNGF protein levels increased in the cortex of aged 3xTg-AD mice, whereas TrkA protein levels were reduced in a gender-dependent manner in aged mutant mice. In contrast, p75(NTR) protein cortical levels were stable but increased in the hippocampus of aged 3xTg-AD mice. These data demonstrate that cholinotrophic alterations in 3xTg-AD mice are age- and gender-dependent and more pronounced in the hippocampus, a structure more severely affected by Aβ plaque pathology. PMID:20937383

  18. System for adding sulfur to a fuel cell stack system for improved fuel cell stability

    DOEpatents

    Mukerjee, Subhasish; Haltiner, Jr., Karl J; Weissman, Jeffrey G.

    2012-03-06

    A system for adding sulfur to a fuel cell stack, having a reformer adapted to reform a hydrocarbon fuel stream containing sulfur contaminants, thereby providing a reformate stream having sulfur; a sulfur trap fluidly coupled downstream of the reformer for removing sulfur from the reformate stream, thereby providing a desulfurized reformate stream; and a metering device in fluid communication with the reformate stream upstream of the sulfur trap and with the desulfurized reformate stream downstream of the sulfur trap. The metering device is adapted to bypass a portion of the reformate stream to mix with the desulfurized reformate stream, thereby producing a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.

  19. Stability of Schwarzschild-AdS for the Spherically Symmetric Einstein-Klein-Gordon System

    NASA Astrophysics Data System (ADS)

    Holzegel, Gustav; Smulevici, Jacques

    2013-01-01

    In this paper, we study the global behavior of solutions to the spherically symmetric coupled Einstein-Klein-Gordon (EKG) system in the presence of a negative cosmological constant. For the Klein-Gordon mass-squared satisfying a ≥ -1 (the Breitenlohner-Freedman bound being a > -9/8), we prove that the Schwarzschild-AdS spacetimes are asymptotically stable: Small perturbations of Schwarzschild-AdS initial data again lead to regular black holes, with the metric on the black hole exterior approaching, at an exponential rate, a Schwarzschild-AdS spacetime. The main difficulties in the proof arise from the lack of monotonicity for the Hawking mass and the asymptotically AdS boundary conditions, which render even (part of) the orbital stability intricate. These issues are resolved in a bootstrap argument on the black hole exterior, with the redshift effect and weighted Hardy inequalities playing the fundamental role in the analysis. Both integrated decay and pointwise decay estimates are obtained. As a corollary of our estimates on the Klein-Gordon field, one obtains in particular exponential decay in time of spherically-symmetric solutions to the linear Klein-Gordon equation on Schwarzschild-AdS.

  20. Adding a Mission to the Joint Polar Satellite System (JPSS) Common Ground System (CGS)

    NASA Astrophysics Data System (ADS)

    Miller, S. W.; Grant, K. D.; Jamilkowski, M. L.

    2014-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners. The CGS provides a wide range of support to a number of missions: 1) Command and control and mission management for the Suomi National Polar-orbiting Partnership (S-NPP) mission today, expanding this support to the JPSS-1 satellite and the Polar Free Flyer mission in 2017 2) Data acquisition via a Polar Receptor Network (PRN) for S-NPP, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the Department of Defense (DoD) 3) Data routing over a global fiber Wide Area Network (WAN) for S-NPP, JPSS-1, Polar Free Flyer, GCOM-W1, POES, DMSP, Coriolis/WindSat, the NASA Space Communications and Navigation (SCaN, which includes several Earth Observing System [EOS] missions), MetOp for the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Science Foundation (NSF) 4) Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 With this established infrastructure and existing suite of missions, the CGS

  1. Dynamical systems analysis of spike-adding mechanisms in transient bursts.

    PubMed

    Nowacki, Jakub; Osinga, Hinke M; Tsaneva-Atanasova, Krasimira

    2012-01-01

    Transient bursting behaviour of excitable cells, such as neurons, is a common feature observed experimentally, but theoretically, it is not well understood. We analyse a five-dimensional simplified model of after-depolarisation that exhibits transient bursting behaviour when perturbed with a short current injection. Using one-parameter continuation of the perturbed orbit segment formulated as a well-posed boundary value problem, we show that the spike-adding mechanism is a canard-like transition that has a different character from known mechanisms for periodic burst solutions. The biophysical basis of the model gives a natural time-scale separation, which allows us to explain the spike-adding mechanism using geometric singular perturbation theory, but it does not involve actual bifurcations as for periodic bursts. We show that unstable sheets of the critical manifold, formed by saddle equilibria of the system that only exist in a singular limit, are responsible for the spike-adding transition; the transition is organised by the slow flow on the critical manifold near folds of this manifold. Our analysis shows that the orbit segment during the spike-adding transition includes a fast transition between two unstable sheets of the slow manifold that are of saddle type. We also discuss a different parameter regime where the presence of additional saddle equilibria of the full system alters the spike-adding mechanism. PMID:22655748

  2. Experimental verification of neutron phenomenology in lead and transmutation by adiabatic resonance crossing in accelerator driven systems

    NASA Astrophysics Data System (ADS)

    Arnould, H.; Bompas, C. A.; del Moral, R.; Lacoste, V.; Vlachoudis, V.; Aleixandre, J.; Bueno, J.; Cerro, E.; González, O.; Tamarit, J.; Andriamonje, S.; Brozzi, D.; Buono, S.; Carminati, F.; Casagrande, F.; Cennini, P.; Collar, J. I.; Dumps, L.; Gelès, C.; Goulas, I.; Fernández, R.; Kadi, Y.; Klapisch, R.; Oropesa, J.; Placci, A.; Revol, J.-P.; Rubbia, C.; Rubio, J. A.; Saldaa, F.; Embid, M.; Gálvez, J.; López, C.; Pérez-Enciso, E.; Poza, M.; Sirvent, C.; Vieira, S.; Abánades, A.; Garcia, J.; Martinez-Val, J. M.; Perlado, M.; González, E.; Hussonnois, M.; Le Naour, C.; Trubert, D.; Belle, E.; Giorni, A.; Heuer, D.; Loiseaux, J. M.; Méplan, O.; Nifenecker, H.; Schussler, F.; Viano, J. B.; Angelopoulos, A.; Apostolakis, A.; Karaiskos, P.; Sakelliou, L.; Kokkas, P.; Pavlopoulos, P.; Eleftheriadis, C.; Kitis, G.; Papadopoulos, I.; Savvidis, E.; Tzima, A.; Zioutas, K.; Diez, S.; Pérez-Navarro, A.

    1999-07-01

    Energy and space distributions of spallation neutrons (from 2.5 and 3.57 GeV/c CERN proton beams) slowing down in a 3.3 x 3.3 x 3 m3 lead volume and neutron capture rates on long-lived fission fragments 99Tc and 129I demonstrate that Adiabatic Resonance Crossing (ARC) can be used to eliminate efficiently such nuclear waste and validate innovative simulation.

  3. An artificial immune system approach with secondary response for misbehavior detection in mobile ad hoc networks.

    PubMed

    Sarafijanović, Slavisa; Le Boudec, Jean-Yves

    2005-09-01

    In mobile ad hoc networks, nodes act both as terminals and information relays, and they participate in a common routing protocol, such as dynamic source routing (DSR). The network is vulnerable to routing misbehavior, due to faulty or malicious nodes. Misbehavior detection systems aim at removing this vulnerability. In this paper, we investigate the use of an artificial immune system (AIS) to detect node misbehavior in a mobile ad hoc network using DSR. The system is inspired by the natural immune system (IS) of vertebrates. Our goal is to build a system that, like its natural counterpart, automatically learns, and detects new misbehavior. We describe our solution for the classification task of the AIS; it employs negative selection and clonal selection, the algorithms for learning and adaptation used by the natural IS. We define how we map the natural IS concepts such as self, antigen, and antibody to a mobile ad hoc network and give the resulting algorithm for classifying nodes as misbehaving. We implemented the system in the network simulator Glomosim; we present detection results and discuss how the system parameters affect the performance of primary and secondary response. Further steps will extend the design by using an analogy to the innate system, danger signal, and memory cells.

  4. Vehicular ad hoc network for a surveillance system using multifrequency band enhancement

    NASA Astrophysics Data System (ADS)

    Bunruangses, Montree; Sunat, Khamron; Mitatha, Somsak; Yupapin, Preecha P.

    2010-09-01

    We present a new design of a surveillance system via a vehicular ad hoc network (VANET) integrated by a 3-G or 4-G cellular wireless network. We propose dense wavelength division multiplexing wavelength enhancement for increasing the channel capacity and signal security. Increase in the number of channels can be obtained by increasing the wavelength density. Signal security is introduced by a specific wavelength filter controlled by the central operator. Optical communication wavelength enhancement is reviewed. The advantage of this proposed system is that it can easily be implemented and incorporated into the existing communication link in either a cellular or ad hoc wireless system, where signal security and hence privacy can be provided.

  5. A Dirichlet reputation system in reliable routing of wireless ad hoc network

    SciTech Connect

    Yang, Dr. Li; Cui, Xiaohui; Cemerlic, Alma

    2010-01-01

    Ad hoc networks are very helpful in situations when no fixed network infrastructure is available, such as natural disasters and military conflicts. In such a network, all wireless nodes are equal peers simultaneously serving as both senders and routers for other nodes. Therefore, how to route packets through reliable paths becomes a fundamental problems when behaviors of certain nodes deviate from wireless ad hoc routing protocols. We proposed a novel Dirichlet reputation model based on Bayesian inference theory which evaluates reliability of each node in terms of packet delivery. Our system offers a way to predict and select a reliable path through combination of first-hand observation and second-hand reputation reports. We also proposed moving window mechanism which helps to adjust ours responsiveness of our system to changes of node behaviors. We integrated the Dirichlet reputation into routing protocol of wireless ad hoc networks. Our extensive simulation indicates that our proposed reputation system can improve good throughput of the network and reduce negative impacts caused by misbehaving nodes.

  6. A flexible statistics web processing service--added value for information systems for experiment data.

    PubMed

    Heimann, Dennis; Nieschulze, Jens; König-Ries, Birgitta

    2010-01-01

    Data management in the life sciences has evolved from simple storage of data to complex information systems providing additional functionalities like analysis and visualization capabilities, demanding the integration of statistical tools. In many cases the used statistical tools are hard-coded within the system. That leads to an expensive integration, substitution, or extension of tools because all changes have to be done in program code. Other systems are using generic solutions for tool integration but adapting them to another system is mostly rather extensive work. This paper shows a way to provide statistical functionality over a statistics web service, which can be easily integrated in any information system and set up using XML configuration files. The statistical functionality is extendable by simply adding the description of a new application to a configuration file. The service architecture as well as the data exchange process between client and service and the adding of analysis applications to the underlying service provider are described. Furthermore a practical example demonstrates the functionality of the service. PMID:20410555

  7. a European Global Navigation Satellite System — the German Market and Value Adding Chain Effects

    NASA Astrophysics Data System (ADS)

    Vollerthun, A.; Wieser, M.

    2002-03-01

    Since Europe is considering to establish a "market-driven" European Global Navigation Satellite System, the German Center of Aerospace initiated a market research to justify a German investment in such a European project. The market research performed included the following market segments: aviation, railway, road traffic, shipping, surveying, farming, military, space applications, leisure, and sport. In these market segments, the forementioned inputs were determined for satellite navigation hardware (receivers) as well as satellite navigation services. The forecast period was from year 2007 to 2017. For the considered period, the market amounts to a total of DM 83.0 billion (approx. US $50 billion), whereas the satellite navigation equipment market makes up DM 39.8 billion, and charges for value-added-services amount to DM 43.2 billion. On closer examination road traffic can be identified as the dominant market share, both in the receiver-market and service-market. With a share of 96% for receivers and 73% for services the significance of the road traffic segment becomes obvious. The second part of this paper investigates the effects the market potential has on the Value-Adding-Chain. Therefore, all participants in the Value-Adding-Chain are identified, using industrial cost structure models the employment effect is analyzed, and possible tax revenues for the state are examined.

  8. Trilateration-based localization algorithm for ADS-B radar systems

    NASA Astrophysics Data System (ADS)

    Huang, Ming-Shih

    Rapidly increasing growth and demand in various unmanned aerial vehicles (UAV) have pushed governmental regulation development and numerous technology research advances toward integrating unmanned and manned aircraft into the same civil airspace. Safety of other airspace users is the primary concern; thus, with the introduction of UAV into the National Airspace System (NAS), a key issue to overcome is the risk of a collision with manned aircraft. The challenge of UAV integration is global. As automatic dependent surveillance-broadcast (ADS-B) system has gained wide acceptance, additional exploitations of the radioed satellite-based information are topics of current interest. One such opportunity includes the augmentation of the communication ADS-B signal with a random bi-phase modulation for concurrent use as a radar signal for detecting other aircraft in the vicinity. This dissertation provides detailed discussion about the ADS-B radar system, as well as the formulation and analysis of a suitable non-cooperative multi-target tracking method for the ADS-B radar system using radar ranging techniques and particle filter algorithms. In order to deal with specific challenges faced by the ADS-B radar system, several estimation algorithms are studied. Trilateration-based localization algorithms are proposed due to their easy implementation and their ability to work with coherent signal sources. The centroid of three most closely spaced intersections of constant-range loci is conventionally used as trilateration estimate without rigorous justification. In this dissertation, we address the quality of trilateration intersections through range scaling factors. A number of well-known triangle centers, including centroid, incenter, Lemoine point (LP), and Fermat point (FP), are discussed in detail. To the author's best knowledge, LP was never associated with trilateration techniques. According our study, LP is proposed as the best trilateration estimator thanks to the

  9. Strategies for adding adaptive learning mechanisms to rule-based diagnostic expert systems

    NASA Technical Reports Server (NTRS)

    Stclair, D. C.; Sabharwal, C. L.; Bond, W. E.; Hacke, Keith

    1988-01-01

    Rule-based diagnostic expert systems can be used to perform many of the diagnostic chores necessary in today's complex space systems. These expert systems typically take a set of symptoms as input and produce diagnostic advice as output. The primary objective of such expert systems is to provide accurate and comprehensive advice which can be used to help return the space system in question to nominal operation. The development and maintenance of diagnostic expert systems is time and labor intensive since the services of both knowledge engineer(s) and domain expert(s) are required. The use of adaptive learning mechanisms to increment evaluate and refine rules promises to reduce both time and labor costs associated with such systems. This paper describes the basic adaptive learning mechanisms of strengthening, weakening, generalization, discrimination, and discovery. Next basic strategies are discussed for adding these learning mechanisms to rule-based diagnostic expert systems. These strategies support the incremental evaluation and refinement of rules in the knowledge base by comparing the set of advice given by the expert system (A) with the correct diagnosis (C). Techniques are described for selecting those rules in the in the knowledge base which should participate in adaptive learning. The strategies presented may be used with a wide variety of learning algorithms. Further, these strategies are applicable to a large number of rule-based diagnostic expert systems. They may be used to provide either immediate or deferred updating of the knowledge base.

  10. Mechanisms for lowering of interfacial tension in alkali/acidic oil systems; Effect of added surfactant

    SciTech Connect

    Rudin, J. Wasan, D.T. . Dept. of Chemical Engineering)

    1992-08-01

    This paper reports that experimental studies are conducted in order to determine the physicochemical mechanism responsible for lowering of interfacial tension in alkali, surfactant, and surfactant-enhanced alkali/acidic oil systems. A well-defined model oil is chosen to examine the influence of various surfactants and surfactant mixtures, such as oleic acid and its ionic counterpart, sodium dodecyl sulfate, petroleum sulfonate, and isobutanol, on equilibrium interfacial tension. With added surfactant alone, the interfacial tension goes through an ultralow minimum with increasing acid concentration. This proves for the first time that the un-ionized acid species plays a major role in affecting interfacial tension, and the ionized acid species.

  11. A climate simulation of the first millennium AD using a comprehensive Earth System Model

    NASA Astrophysics Data System (ADS)

    Wagner, Sebastian; Zorita, Eduardo

    2014-05-01

    Investigations of past climate using fully coupled comprehensive Earth System Models are restricted by the large computational costs of these simulations. Here we present first results from an on-going simulation with the MPI-ESM-P starting in year 100 BC. The simulation is forced with changes in orbital forcing and long-term solar variations augmented by a synthetic 11-year cycle including an interactive ozone cycle. For the first time also changes in volcanic activity are implemented based on the reconstruction method by Crowley and Unterman (2012). The basis of the extended volcanic forcing in terms of aerosol optical depth and effective radius are new sulfate estimations from ice cores from Greenland (NEEM) and Antarctica (WAIS) presented by Sigl et al. (2013). Because the NEEM record only reaches back as far as 79 AD, the time until 100 BC was filled by earlier information contained in the Dye 3 and GRIP record (Clausen et al., 1997). Compared to the 2nd millennium AD, the first millennium does however show a considerably reduced amount of large explosive tropical eruptions. On hemispheric and global scale the large outbreaks around the years 530 and 740 AD are well reflected as negative temperature anomalies. The 79 AD Vesuvius eruption does not however produce a pronounced hemispheric signal. The amount of sulphate ejected into the stratosphere may have been too low for a sustained hemispheric-scale cooling. The large eruption of 530 AD (so called 'mystic cloud') is however well reflected within the temperature evolution and is more pronounced over the northern hemisphere during summertime. On longer, multi-centennial, time scales, global temperatures show a slight decrease. This decrease is more pronounced over the NH hemisphere during JJA and is caused by the decline in the TOA short wave incoming radiation. Over the extratropical SH changes in orbital forcing are not reflected in temperature trends as clearly as over the NH due to the larger oceanic and

  12. Soil Decomposition of Added Organic C in an Organic Farming System

    NASA Astrophysics Data System (ADS)

    Kpomblekou-A, Kokoasse; Sissoko, Alassane; McElhenney, Wendell

    2015-04-01

    In the United States, large quantities of poultry waste are added every year to soil under organic management. Decomposition of the added organic C releases plant nutrients, promotes soil structure, and plays a vital role in the soil food web. In organic agriculture the added C serves as the only source of nutrients for plant growth. Thus understanding the decomposition rates of such C in organic farming systems are critical in making recommendations of organic inputs to organic producers. We investigated and compared relative accumulation and decomposition of organic C in an organic farming system trial at the George Washington Carver Agricultural Experiment Station at Tuskegee, Alabama on a Marvyn sandy loam (fine-loamy, kaolinitic, thermic, Typic Kanhapludults) soil. The experimental design was a randomized complete block with four replicates and four treatments. The main plot (54' × 20') was split into three equal subplots to plant three sweet potato cultivars. The treatments included a weed (control with no cover crop, no fertilizer), crimson clover alone (CC), crimson clover plus broiler litter (BL), and crimson clover plus NPK mineral fertilizers (NPK). For five years, late in fall, the field was planted with crimson clover (Trifolium incarnatum L) that was cut with a mower and incorporated into soil the following spring. Moreover, broiler litter (4.65 Mg ha-1) or ammonium nitrate (150 kg N ha-1), triple super phosphate (120 kg P2O5 ha-1), and potassium chloride (160 kg K2O ha-1) were applied to the BL or the NPK plot and planted with sweet potato. Just before harvest, six soil samples were collected within the two middle rows of each sweet potato plot with an auger at incremental depths of 0-1, 1-2, 2-3, 3-5, 5-10, and 10-15 cm. Samples from each subplot and depth were composited and mixed in a plastic bag. The samples were sieved moist through a

  13. Runway Incursion Prevention System ADS-B and DGPS Data Link Analysis Dallas-Fort Worth International Airport

    NASA Technical Reports Server (NTRS)

    Timmerman, J.; Jones, Denise R. (Technical Monitor)

    2001-01-01

    A Runway Incursion Prevention System (RIPS) was tested at the Dallas - Ft. Worth International Airport in October 2000. The system integrated airborne and ground components to provide both pilots and controllers with enhanced situational awareness, supplemental guidance cues, a real-time display of traffic information, and warning of runway incursions in order to prevent runway incidents while also improving operational capability. Rockwell Collins provided and supported a prototype Automatic Dependent Surveillance - Broadcast (ADS-B) system using 1090 MHz and a prototype Differential GPS (DGPS) system onboard the NASA Boeing 757 research aircraft. This report describes the Rockwell Collins contributions to the RIPS flight test, summarizes the development process, and analyzes both ADS-B and DGPS data collected during the flight test. In addition, results are report on interoperability tests conducted between the NASA Advanced General Aviation Transport Experiments (AGATE) ADS-B flight test system and the NASA Boeing 757 ADS-B system.

  14. Implementation and performance evaluation of mobile ad hoc network for Emergency Telemedicine System in disaster areas.

    PubMed

    Kim, J C; Kim, D Y; Jung, S M; Lee, M H; Kim, K S; Lee, C K; Nah, J Y; Lee, S H; Kim, J H; Choi, W J; Yoo, S K

    2009-01-01

    So far we have developed Emergency Telemedicine System (ETS) which is a robust system using heterogeneous networks. In disaster areas, however, ETS cannot be used if the primary network channel is disabled due to damages on the network infrastructures. Thus we designed network management software for disaster communication network by combination of Mobile Ad hoc Network (MANET) and Wireless LAN (WLAN). This software maintains routes to a Backbone Gateway Node in dynamic network topologies. In this paper, we introduce the proposed disaster communication network with management software, and evaluate its performance using ETS between Medical Center and simulated disaster areas. We also present the results of network performance analysis which identifies the possibility of actual Telemedicine Service in disaster areas via MANET and mobile network (e.g. HSDPA, WiBro).

  15. Aharonov-Bohm effect on AdS{sub 2} and nonlinear supersymmetry of reflectionless Poeschl-Teller system

    SciTech Connect

    Correa, Francisco Jakubsky, Vit Plyushchay, Mikhail S.

    2009-05-15

    We explain the origin and the nature of a special nonlinear supersymmetry of a reflectionless Poeschl-Teller system by the Aharonov-Bohm effect for a non-relativistic particle on the AdS{sub 2}. A key role in the supersymmetric structure appearing after reduction by a compact generator of the AdS{sub 2} isometry is shown to be played by the discrete symmetries related to the space and time reflections in the ambient Minkowski space. We also observe that a correspondence between the two quantum non-relativistic systems is somewhat of the AdS/CFT holography nature.

  16. Delay-dependent asymptotic stability of mobile ad-hoc networks: A descriptor system approach

    NASA Astrophysics Data System (ADS)

    Yang, Juan; Yang, Dan; Huang, Bin; Zhang, Xiao-Hong; Luo, Jian-Lu

    2014-07-01

    In order to analyze the capacity stability of the time-varying-propagation and delay-dependent of mobile ad-hoc networks (MANETs), in this paper, a novel approach is proposed to explore the capacity asymptotic stability for the delay-dependent of MANETs based on non-cooperative game theory, where the delay-dependent conditions are explicitly taken into consideration. This approach is based on the Lyapunov—Krasovskii stability theory for functional differential equations and the linear matrix inequality (LMI) technique. A corresponding Lyapunov—Krasovskii functional is introduced for the stability analysis of this system with use of the descriptor and “neutral-type” model transformation without producing any additional dynamics. The delay-dependent stability criteria are derived for this system. Conditions are given in terms of linear matrix inequalities, and for the first time referred to neutral systems with the time-varying propagation and delay-dependent stability for capacity analysis of MANETs. The proposed criteria are less conservative since they are based on an equivalent model transformation. Furthermore, we also provide an effective and efficient iterative algorithm to solve the constrained stability control model. Simulation experiments have verified the effectiveness and efficiency of our algorithm.

  17. A Threshold-Adaptive Reputation System on Mobile Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Tsai, Hsiao-Chien; Lo, Nai-Wei; Wu, Tzong-Chen

    In recent years huge potential benefits from novel applications in mobile ad hoc networks (MANET) have been discussed extensively. However, without robust security mechanisms and systems to provide safety shell through the MANET infrastructure, MANET applications can be vulnerable and hammered by malicious attackers easily. In order to detect misbehaved message routing and identify malicious attackers in MANET, schemes based on reputation concept have shown their advantages in this area in terms of good scalability and simple threshold-based detection strategy. We observed that previous reputation schemes generally use predefined thresholds which do not take into account the effect of behavior dynamics between nodes in a period of time. In this paper, we propose a Threshold-Adaptive Reputation System (TARS) to overcome the shortcomings of static threshold strategy and improve the overall MANET performance under misbehaved routing attack. A fuzzy-based inference engine is introduced to evaluate the trustiness of a node's one-hop neighbors. Malicious nodes whose trust values are lower than the adaptive threshold, will be detected and filtered out by their honest neighbors during trustiness evaluation process. The results of network simulation show that the TARS outperforms other compared schemes under security attacks in most cases and at the same time reduces the decrease of total packet delivery ratio by 67% in comparison with MANET without reputation system.

  18. Union of Compact Accelerator-Driven Neutron Sources (UCANS) I & II Neutron applications laboratory for ESS-Bilbao

    NASA Astrophysics Data System (ADS)

    Terrón, S.; Magán, M.; Sordo, F.; Ghiglino, A.; Mart«ınez, F.; Bermejo, F. J.; Perlado, J. M.

    The ESS-Bilbao Accelerator Center site at Lejoa UPV/EHU campus will be provided with a proton accelerator up to 300-400 MeV. In the first construction phase, a beam extraction will be set at the end of the DTL, which will produce a 50 MeV proton beam with an average current of 2.25 mA and 1.5 ms pulses at a frequency of 20 Hz. These beam characteristics allow to configure a low intensity neutron source based on Be (p, n) reactions, which enables experimentation with cold neutrons similar to that of LENS. The total beam power will be 112 kW, so the configuration of the neutron production target will be based on a rotating disk of beryllium slabs facing the beam on one side and a cryogenic methane moderator on the other, with the target-moderator system surrounded by a beryllium reflector. In this paper, first estimates will be presented for thermomechanical conditions of the target cooling scheme, neutron source intensities, and cold neutron pulses.

  19. A Unique U.S. Approach for Accelerator-Driven Warm Dense Matter Research--Preliminary Report

    SciTech Connect

    Logan, B G; Davidson, R C; Barnard, J J; Lee, R

    2004-12-22

    The warm density matter regime of high energy density physics [1, 2, 3] has a high scientific discovery potential for the properties of plasmas at high densities and pressures and at moderate temperatures (kT) in which the Coulomb interaction energy between plasma particles exceed kT. This leads to correlations in the plasma characterized by the dimensionless ''coupling'' parameter {Lambda} > 1, where {Lambda} is defined by {Lambda} = q{sup 2}n{sup 1/3}/kT. Here q is the effective ion charge and n the ion density. Strongly-coupled plasmas with {Lambda} > 1 are difficult to study analytically and by numerical simulation. Many astrophysical systems (e.g., brown dwarfs, and giant planets) and inertial fusion plasmas in the beginning stages of compression fall into this regime. There is an opportunity to develop improved understanding and models through accurate measurements of properties in the large parameter space of temperature and density where data is currently limited or non-existent. X-ray free-electron lasers (Fourth generation light sources), ultra-short pulse and high energy optical lasers, pulsed-power z-pinch x-ray sources, and high explosives are all capable of producing warm dense matter conditions at various temperatures, pressures, and sample sizes. Therefore, the challenge is not how to create warm dense matter conditions, but to create it so that it's fundamental properties can be best studied. The goal is to advance this field of science through a variety of complementary facilities and methods which offer several combinations of desirable attributes: Precise control and uniformity of energy deposition; Large sample sizes compared to diagnostic resolution volumes; A benign environment for diagnostics (low debris and radiation background); High shot rates (10/hour to 1/second) and multiple beamlines/target chambers; and Sites with easy access for broad participation by university scientists and students; and with the technical support for designing

  20. Polarised black holes in AdS

    NASA Astrophysics Data System (ADS)

    Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-06-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.

  1. Spectral energy distributions and model atmosphere parameters of the quadruple system ADS11061.

    NASA Astrophysics Data System (ADS)

    Al-Wardat, M. A.

    2002-06-01

    The spectral energy distribution between λ 3700 Å, and λ 8100 Å, of the two subsystems 41Dra and 40Dra of the multiple system ADS11061 has been introduced with a description of methodology of getting the spectra on Carl-Zeiss-Jena 1 m telescope of Special Astrophysical Observatory. The spectral type and luminosity class for each of them have been deduced and compared with earlier investigations, the B,V, and R magnitudes and B-V colour indices have been computed, the interstellar reddening of both subsystems have been calculated and an envelope around 40Dra has been suggested, model atmosphere parameters of the subsystem 40Dra' components have been derived: TeffBa =6100 degr K, TeffBb =6100 degr K, lg gBa=4.03, lg gBb=4.20, RBa=1.82R⊙, RBb=1.44R⊙, and finally the formation and evolution of the system have been discussed depending on the filament fragmentation process.

  2. Investigations of high-speed optical transmission systems employing Absolute Added Correlative Coding (AACC)

    NASA Astrophysics Data System (ADS)

    Dong-Nhat, Nguyen; Elsherif, Mohamed A.; Malekmohammadi, Amin

    2016-07-01

    A novel multilevel modulation format based on partial-response signaling called Absolute Added Correlative Coding (AACC) is proposed and numerically demonstrated for high-speed fiber-optic communication systems. A bit error rate (BER) estimation model for the proposed multilevel format has also been developed. The performance of AACC is examined and compared against other prevailing On-Off-Keying and multilevel modulation formats e.g. non-return-to-zero (NRZ), 50% return-to-zero (RZ), 67% carrier-suppressed return-to-zero (CS-RZ), duobinary and four-level pulse-amplitude modulation (4-PAM) in terms of receiver sensitivity, spectral efficiency and dispersion tolerance. Calculated receiver sensitivity at a BER of 10-9 and chromatic dispersion tolerance of the proposed system are ∼-28.3 dBm and ∼336 ps/nm, respectively. The performance of AACC is delineated to be improved by 7.8 dB in terms of receiver sensitivity compared to 4-PAM in back-to-back scenario. The comparison results also show a clear advantage of AACC in achieving longer fiber transmission distance due to the higher dispersion tolerance in optical access networks.

  3. Investigations of high-speed optical transmission systems employing Absolute Added Correlative Coding (AACC)

    NASA Astrophysics Data System (ADS)

    Dong-Nhat, Nguyen; Elsherif, Mohamed A.; Malekmohammadi, Amin

    2016-07-01

    A novel multilevel modulation format based on partial-response signaling called Absolute Added Correlative Coding (AACC) is proposed and numerically demonstrated for high-speed fiber-optic communication systems. A bit error rate (BER) estimation model for the proposed multilevel format has also been developed. The performance of AACC is examined and compared against other prevailing On-Off-Keying and multilevel modulation formats e.g. non-return-to-zero (NRZ), 50% return-to-zero (RZ), 67% carrier-suppressed return-to-zero (CS-RZ), duobinary and four-level pulse-amplitude modulation (4-PAM) in terms of receiver sensitivity, spectral efficiency and dispersion tolerance. Calculated receiver sensitivity at a BER of 10-9 and chromatic dispersion tolerance of the proposed system are ˜-28.3 dBm and ˜336 ps/nm, respectively. The performance of AACC is delineated to be improved by 7.8 dB in terms of receiver sensitivity compared to 4-PAM in back-to-back scenario. The comparison results also show a clear advantage of AACC in achieving longer fiber transmission distance due to the higher dispersion tolerance in optical access networks.

  4. An artificial immune system for securing mobile ad hoc networks against intrusion attacks

    NASA Astrophysics Data System (ADS)

    Hortos, William S.

    2003-08-01

    To mitigate the problem of intrusion attacks by malicious nodes in mobile ad hoc networks (MANETs), security attributes and quantifiable trust levels, unique to the MANET's transient, self-organizing topology, augment or replace traditional protocol metrics of throughput, packet delay and hop-count in the ad hoc route discovery procedures. The new features are unique to the candidate security protocol, which views security as a quality metric to improve the relevance of the routes discovered by established reactive ad hoc routing protocols. Attributes of a secure route are identified in order to define the appropriate metrics to quantify the "level of security" associated with the protocol messaging and the detection of malicious activities by some intrusive nodes. A state vector of features and metrics based on the published Secure Routing Protocol (SRP) for MANETs is constructed to encode network security characteristics. This route discovery protocol mitigates the detrimental effects of various malicious behaviors to provide trustworthy connectivity information. The protocol ensures that fabricated, compromised, or replayed route replies would either be rejected or never reach the querying source node. In this paper, the pattern of values, taken by the state vector of the SRP features in the route request, discovery and reply operations, are analyzed to detect evidence of intrusion attacks by malicious nodes that could lead to denial of service and network shutdown. The pattern analysis applies a technique based on negative selection found in natural immune systems that can detect extraneous patterns in the (nonself) space that is the complement of vector values associated with correct route discovery and route maintenance. The immune system is well-suited to the distributed nature of the MANET. It does not rely on a central controller, but instead uses a distributed detection and response mechanism in order to respond to foreign invaders, mirroring the

  5. Study on transient beam loading compensation for China ADS proton linac injector II

    NASA Astrophysics Data System (ADS)

    Gao, Zheng; He, Yuan; Wang, Xian-Wu; Chang, Wei; Zhang, Rui-Feng; Zhu, Zheng-Long; Zhang, Sheng-Hu; Chen, Qi; Powers, Tom

    2016-05-01

    Significant transient beam loading effects were observed during beam commissioning tests of prototype II of the injector for the accelerator driven sub-critical (ADS) system, which took place at the Institute of Modern Physics, Chinese Academy of Sciences, between October and December 2014. During these tests experiments were performed with continuous wave (CW) operation of the cavities with pulsed beam current, and the system was configured to make use of a prototype digital low level radio frequency (LLRF) controller. The system was originally operated in pulsed mode with a simple proportional plus integral and deviation (PID) feedback control algorithm, which was not able to maintain the desired gradient regulation during pulsed 10 mA beam operations. A unique simple transient beam loading compensation method which made use of a combination of proportional and integral (PI) feedback and feedforward control algorithm was implemented in order to significantly reduce the beam induced transient effect in the cavity gradients. The superconducting cavity field variation was reduced to less than 1.7% after turning on this control algorithm. The design and experimental results of this system are presented in this paper. Supported by National Natural Science Foundation of China (91426303, 11525523)

  6. Proliferation Potential of Accelerator-Drive Systems: Feasibility Calculations

    SciTech Connect

    Riendeau, C.D.; Moses, D.L.; Olson, A.P.

    1998-11-01

    Accelerator-driven systems for fissile materials production have been proposed and studied since the early 1950s. Recent advances in beam power levels for small accelerators have raised the possibility that such use could be feasible for a potential proliferator. The objective of this study is to review the state of technology development for accelerator-driven spallation neutron sources and subcritical reactors. Energy and power requirements were calculated for a proton accelerator-driven neutron spallation source and subcritical reactors to produce a significant amount of fissile material--plutonium.

  7. The ADS Abstract Service: A Free Search System for Literature in Astronomy, Planetary Sciences, Physics, Geophysics, and Instrumentation.

    NASA Astrophysics Data System (ADS)

    Eichhorn, G.; Accomazzi, A.; Grant, C. S.; Kurtz, M. J.; Rey Bacaicoa, V.; Murray, S. S.

    2002-05-01

    The Astrophysics Data System (ADS) provides access to the astronomical literature through the World Wide Web. It is a NASA funded project and access to all the ADS services is free to everybody world-wide. The ADS Abstract Service allows searching of four databases with abstracts in Astronomy, Instrumentation, Physics/Geophysics, and the astro-ph Preprints with a total of almost 2.5 million references in the databases. The system also provides access to reference and citation information, links to on-line data and other on-line information, and to on-line electronic journals. In addition the ADS has 1.9 million scanned article pages from about 250,000 articles, dating back as far as 1829. The ADS Article Service contains the full articles for most of the astronomical literature back to volume 1. It contains the scanned pages of all the major journals in Astronomy (Astrophysical Journal, Astronomical Journal, Astronomy & Astrophysics, Monthly Notices of the Royal Astronomical Society, and Solar Physics), as well as most smaller journals back to volume 1 for each of these journals. One important aspect of the ADS is the system of links to other data systems. We have currently more than 6 million links to other on-line resources, including on-line data and on-line journal articles. There are currently more than 10,000 regular users (more than 10 queries/month). The total number of users is greater than 50,000 per month. They issue almost 1 million queries per month and receive more than 30 million records and 1.2 million scanned article pages per month. The ADS is accessed from almost 100 countries. Approximately 1/3 of the use is from the USA, 1/3 from Europe, and 1/3 from the rest of the world. Usage depends primarily on the number of astronomers in each country, but also on the Gross Domestic Product of that country. In order to improve access from different parts of the world, we maintain 9 mirror sites of the ADS in Brazil, Chile, China, England, France, Germany

  8. Emergency Situation Prediction Mechanism: A Novel Approach for Intelligent Transportation System Using Vehicular Ad Hoc Networks.

    PubMed

    Ganeshkumar, P; Gokulakrishnan, P

    2015-01-01

    In Indian four-lane express highway, millions of vehicles are travelling every day. Accidents are unfortunate and frequently occurring in these highways causing deaths, increase in death toll, and damage to infrastructure. A mechanism is required to avoid such road accidents at the maximum to reduce the death toll. An Emergency Situation Prediction Mechanism, a novel and proactive approach, is proposed in this paper for achieving the best of Intelligent Transportation System using Vehicular Ad Hoc Network. ESPM intends to predict the possibility of occurrence of an accident in an Indian four-lane express highway. In ESPM, the emergency situation prediction is done by the Road Side Unit based on (i) the Status Report sent by the vehicles in the range of RSU and (ii) the road traffic flow analysis done by the RSU. Once the emergency situation or accident is predicted in advance, an Emergency Warning Message is constructed and disseminated to all vehicles in the area of RSU to alert and prevent the vehicles from accidents. ESPM performs well in emergency situation prediction in advance to the occurrence of an accident. ESPM predicts the emergency situation within 0.20 seconds which is comparatively less than the statistical value. The prediction accuracy of ESPM against vehicle density is found better in different traffic scenarios.

  9. VehiHealth: An Emergency Routing Protocol for Vehicular Ad Hoc Network to Support Healthcare System.

    PubMed

    Bhoi, S K; Khilar, P M

    2016-03-01

    Survival of a patient depends on effective data communication in healthcare system. In this paper, an emergency routing protocol for Vehicular Ad hoc Network (VANET) is proposed to quickly forward the current patient status information from the ambulance to the hospital to provide pre-medical treatment. As the ambulance takes time to reach the hospital, ambulance doctor can provide sudden treatment to the patient in emergency by sending patient status information to the hospital through the vehicles using vehicular communication. Secondly, the experienced doctors respond to the information by quickly sending a treatment information to the ambulance. In this protocol, data is forwarded through that path which has less link breakage problem between the vehicles. This is done by calculating an intersection value I v a l u e for the neighboring intersections by using the current traffic information. Then the data is forwarded through that intersection which has minimum I v a l u e . Simulation results show VehiHealth performs better than P-GEDIR, GyTAR, A-STAR and GSR routing protocols in terms of average end-to-end delay, number of link breakage, path length, and average response time.

  10. Emergency Situation Prediction Mechanism: A Novel Approach for Intelligent Transportation System Using Vehicular Ad Hoc Networks

    PubMed Central

    Gokulakrishnan, P.

    2015-01-01

    In Indian four-lane express highway, millions of vehicles are travelling every day. Accidents are unfortunate and frequently occurring in these highways causing deaths, increase in death toll, and damage to infrastructure. A mechanism is required to avoid such road accidents at the maximum to reduce the death toll. An Emergency Situation Prediction Mechanism, a novel and proactive approach, is proposed in this paper for achieving the best of Intelligent Transportation System using Vehicular Ad Hoc Network. ESPM intends to predict the possibility of occurrence of an accident in an Indian four-lane express highway. In ESPM, the emergency situation prediction is done by the Road Side Unit based on (i) the Status Report sent by the vehicles in the range of RSU and (ii) the road traffic flow analysis done by the RSU. Once the emergency situation or accident is predicted in advance, an Emergency Warning Message is constructed and disseminated to all vehicles in the area of RSU to alert and prevent the vehicles from accidents. ESPM performs well in emergency situation prediction in advance to the occurrence of an accident. ESPM predicts the emergency situation within 0.20 seconds which is comparatively less than the statistical value. The prediction accuracy of ESPM against vehicle density is found better in different traffic scenarios. PMID:26065014

  11. Small Delay and High Performance AD/DA Converters of Lease Circuit System for AM&FM Broadcast

    NASA Astrophysics Data System (ADS)

    Takato, Kenji; Suzuki, Dai; Ishii, Takashi; Kobayashi, Masato; Yamada, Hirokazu; Amano, Shigeru

    Many AM&FM broadcasting stations in Japan are connected by the leased circuit system of NTT. Small delay and high performance AD/DA converter was developed for the system. The system was designed based on ITU-T J.41 Recommendation (384kbps), the transmission signal is 11bit-32 kHz where the Gain-frequency characteristics between 40Hz to 15kHz have to be quite flat. The ΔΣAD/DA converter LSIs for audio application in the market today realize very high performance. However the performance is not enough for the leased circuit system. We found that it is not possible to meet the delay and Gain-frequency requirements only by using ΔΣAD/DA converter LSI in normal operation, because 15kHz the highest frequency and 16kHz Nyquist frequency are too close, therefore there are aliasing around Nyquist frequency. In this paper, we designed AD/DA architecture having small delay (1msec) and sharp cut off LPF (100dB attenuation at 16kHz, and 1500dB/Oct from 15kHz to 16kHz) by operating ΔΣAD/DA converter LSIs over-sampling rate such as 128kHz and by adding custom LPF designed Infinite Impulse Response (IIR) filter. The IIR filter is a 16th order elliptic type and it is consist of eight biquad filters in series. We described how to evaluate the stability of IIR filter theoretically by calculating frequency response, Pole and Zero Layout and impulse response of each biquad filter, and experimentally by adding overflow detection circuit on each filters and input overlord signal.

  12. Myrrha, Technology Development for the Realisation of ADS in Eu:. Current Status & Prospects for Realisation

    NASA Astrophysics Data System (ADS)

    Fernandez, R.; Abderrahim, H. Aït; Baeten, P.; de Bruyn, D.; Maes, D.; Mazouzi, A. Al; Ariën, B.; Malambu, E.; Schuurmans, P.; Schyns, M.; Sobolev, V.; van den Eynde, G.; Vandeplassche, D.

    2010-06-01

    The coupling between an accelerator, a spallation target and a subcritical core has been studied for the first time at SCK•CEN in collaboration with Ion Beam Applications (IBA, Louvain-la-Neuve) in the frame of the ADONIS project (1995-1997). ADONIS was a small irradiation facility, based on the ADS concept, having a dedicated objective to produce radioisotopes for medical purposes and more particularly 99Mo as a fission product from highly enriched 235U (HEU) fissile targets. The ad-hoc scientific advisory committee recommended extending the purpose of the ADONIS machine to become a Material Testing Reactor (MTR) for material and fuel research, to study the feasibility of transmutation of the minor actinides and to demonstrate at a reasonable power scale the principle of the ADS. The project, since 1998 named MYRRHA, has then evolved to a larger installation. MYRRHA is now conceived as a flexible irradiation facility, able to work as an Accelerator Driven (subcritical mode) and in critical mode. In this way, MYRRHA will allow fuel developments for innovative reactor systems, material developments for GEN IV systems, material developments for fusion reactors, radioisotope production for medical and industrial applications and industrial applications, such as Si-doping. MYRRHA will also demonstrate the ADS full concept by coupling the three components (accelerator, spallation target and subcritical reactor) at reasonable power level to allow operation feedback, scalable to an industrial demonstrator and allow the study of efficient transmutation of high-level nuclear waste. Since MYRRHA is based on the heavy liquid metal technology, the eutectic lead-bismuth, it will be able to significantly contribute to the development of Lead Fast Reactor Technology. Since MYRRHA will also be operated in critical mode, MYRRHA can even better play the role of European Technology Pilot Plant in the roadmap for LFR.

  13. MYRRHA, a Pb-Bi experimental ADS: specific approach to radiation protection aspects.

    PubMed

    Abderrahim, H Aït; Aoust, Th; Malambu, E; Sobolev, V; Van Tichelen, K; De Bruyn, D; Maes, D; Haeck, W; Van den Eynde, G

    2005-01-01

    Since 1998, SCK*CEN, in partnership with IBA s.a. and many European research laboratories, is designing a multipurpose accelerator driven system (ADS) for Research and Development (R&D) applications-MYRRHA-and is conducting an associated R&D support programme. MYRRHA is an ADS under development at Mol in Belgium and is aiming to serve as a basis for the European experimental ADS to provide protons and neutrons for various R&D applications. It consists of a proton accelerator delivering a 350 MeV x 5 mA proton beam to a liquid Pb-Bi spallation target that in turn couples to a Pb-Bi cooled, subcritical fast core. In the first stage, the project focuses mainly on demonstration of the ADS concept, safety research on sub-critical systems and nuclear waste transmutation studies. In a later stage, the device will also be dedicated to research on structural materials, nuclear fuel, liquid metal technology and associated aspects, and on sub-critical reactor physics. Subsequently, it will be used for research on applications such as radioisotope production. A first preliminary conceptual design file of MYRRHA was completed by the end of 2001 and has been reviewed by an International Technical Guidance Committee, which concluded that there are no show stoppers in the project and even though some topics such as the safety studies and the fuel qualification need to be addressed more deeply before concluding it. In this paper, we are reporting on the state-of-the art of the MYRRHA project at the beginning of 2004 and in particular on the radiation shielding assessment and the radiation protection particular aspects through a remote handling operation approach in order to minimise the personnel exposure to radiation.

  14. Chromospherically active stars. 12: ADS 11060 C: A double lined K dwarf binary in a quintuple system

    NASA Technical Reports Server (NTRS)

    Fekel, Francis C.; Henry, Gregory W.; Hampton, Melissa L.; Fried, Robert; Morton, Mary D.

    1994-01-01

    ADS 11060 C is a double lined spectroscopic binary with a period of 25.7631 days and an eccentricity of 0.565. Spectral types of the two stars are estimated as K7 V and MO V with a magnitude difference of about 0.55 mag in V. The stars appear to be somewhat metal rich with respect to the Sun. Despite the relatively large masses of 0.53 and 0.51 solar mass, our photometric observations find no evidence for eclipses and we estimate an inclination of 77 deg plus or minus 11 deg. ADS 11060 C is, however, photometrically variable with a period of 9 plus or minus 1 day and an amplitude of 0.05 mag in V. Thus, it is a newly identified BY Draconis variable. The center-of-mass velocity of ADS 11060 C and an estimated parallax of 0.030 sec support its physical association with ADS 11060 AB, making this a quintuple system. The projected separation of the AB-C system is nearly 1200 AU. Although the log lithium abundances of the two components of ADS 11060 C are only upper limits, less than or equal to -0.14, lithium abundances of the AB-C components appear to be consistent with those of similar stars in the alpha Persei and Pleiades clusters, suggesting an age of about 70 Myr for ADS 11060 AB-C. The system is a possible member of the Pleiades moving group. Listed as an optical counterpart to a source in the ROSAT Wide Field Camera extreme-ultraviolet bright source catalog, both ADS 11060 AB and C may contribute to the observed flux.

  15. Automatic Dependent Surveillance Broadcast (ADS-B) System for Ownership and Traffic Situational Awareness

    NASA Technical Reports Server (NTRS)

    Arteaga, Ricardo A. (Inventor)

    2016-01-01

    The present invention proposes an automatic dependent surveillance broadcast (ADS-B) architecture and process, in which priority aircraft and ADS-B IN traffic information are included in the transmission of data through the telemetry communications to a remote ground control station. The present invention further proposes methods for displaying general aviation traffic information in three and/or four dimension trajectories using an industry standard Earth browser for increased situation awareness and enhanced visual acquisition of traffic for conflict detection. The present invention enable the applications of enhanced visual acquisition of traffic, traffic alerts, and en-route and terminal surveillance used to augment pilot situational awareness through ADS-B IN display and information in three or four dimensions for self-separation awareness.

  16. Hairy AdS solitons

    NASA Astrophysics Data System (ADS)

    Anabalón, Andrés; Astefanesei, Dumitru; Choque, David

    2016-11-01

    We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We examine their thermodynamic properties and discuss the role of these solutions for the existence of first order phase transitions for hairy black holes. The negative energy density associated to hairy AdS solitons can be interpreted as the Casimir energy that is generated in the dual filed theory when the fermions are antiperiodic on the compact coordinate.

  17. Houston, We Have a Problem: Teachers Find No Value in the SAS Education Value-Added Assessment System (EVAAS®)

    ERIC Educational Resources Information Center

    Collins, Clarin

    2014-01-01

    This study examined the SAS Education Value-Added Assessment System (EVAAS®) in practice, as perceived and experienced by teachers in the Southwest School District (SSD). To evaluate teacher effectiveness, SSD is using SAS EVAAS® for high-stakes consequences more than any other district or state in the country. A mixed-method design including a…

  18. Validating "Value Added" in the Primary Grades: One District's Attempts to Increase Fairness and Inclusivity in Its Teacher Evaluation System

    ERIC Educational Resources Information Center

    Amrein-Beardsley, Audrey; Polasky, Sarah; Holloway-Libell, Jessica

    2016-01-01

    One urban district in the state of Arizona sought to use an alternative achievement test (i.e., the Northwest Evaluation Association's (NWEA) Measures of Academic Progress for Primary Grades (MAP)) to include more value-added ineligible teachers in the districts' growth and merit pay system. The goal was to allow for its K-2 teachers to be more…

  19. Fourth-Year Achievement Results on the Tennessee Value-Added Assessment System for Restructuring Schools in Memphis.

    ERIC Educational Resources Information Center

    Ross, Steven M.; Wang, L. Weiping; Alberg, Marty; Sanders, William L.; Wright, S. Paul; Stringfield, Sam

    This paper analyzes data on elementary schools in Memphis, Tennessee, that had reorganized 4 years prior to the study. The Tennessee Value-Added Assessment System (TVAAS) was used to provide performance scores showing students' year-to-year gains, whereas data analyzed for this paper were derived from scores on the TerraNova, the state-mandated…

  20. Ad Duwayhi, Saudi Arabia: Geology and geochronology of a neoproterozoic intrusion-related gold system in the Arabian shield

    USGS Publications Warehouse

    Doebrich, Jeff L.; Zahony, S.G.; Leavitt, J.D.; Portacio, J.S.; Siddiqui, A.A.; Wooden, Joseph L.; Fleck, Robert J.; Stein, Holly J.

    2004-01-01

    In light of our findings at Ad Duwayhi, a reassessment of similar intrusion-hosted deposits in the Arabian shield is warranted, and areas of late- to postorogenic plutonism, particularly in the Afif composite terrane, should be considered prospective for intrusion-related gold systems.

  1. CycADS: an annotation database system to ease the development and update of BioCyc databases.

    PubMed

    Vellozo, Augusto F; Véron, Amélie S; Baa-Puyoulet, Patrice; Huerta-Cepas, Jaime; Cottret, Ludovic; Febvay, Gérard; Calevro, Federica; Rahbé, Yvan; Douglas, Angela E; Gabaldón, Toni; Sagot, Marie-France; Charles, Hubert; Colella, Stefano

    2011-01-01

    In recent years, genomes from an increasing number of organisms have been sequenced, but their annotation remains a time-consuming process. The BioCyc databases offer a framework for the integrated analysis of metabolic networks. The Pathway tool software suite allows the automated construction of a database starting from an annotated genome, but it requires prior integration of all annotations into a specific summary file or into a GenBank file. To allow the easy creation and update of a BioCyc database starting from the multiple genome annotation resources available over time, we have developed an ad hoc data management system that we called Cyc Annotation Database System (CycADS). CycADS is centred on a specific database model and on a set of Java programs to import, filter and export relevant information. Data from GenBank and other annotation sources (including for example: KAAS, PRIAM, Blast2GO and PhylomeDB) are collected into a database to be subsequently filtered and extracted to generate a complete annotation file. This file is then used to build an enriched BioCyc database using the PathoLogic program of Pathway Tools. The CycADS pipeline for annotation management was used to build the AcypiCyc database for the pea aphid (Acyrthosiphon pisum) whose genome was recently sequenced. The AcypiCyc database webpage includes also, for comparative analyses, two other metabolic reconstruction BioCyc databases generated using CycADS: TricaCyc for Tribolium castaneum and DromeCyc for Drosophila melanogaster. Linked to its flexible design, CycADS offers a powerful software tool for the generation and regular updating of enriched BioCyc databases. The CycADS system is particularly suited for metabolic gene annotation and network reconstruction in newly sequenced genomes. Because of the uniform annotation used for metabolic network reconstruction, CycADS is particularly useful for comparative analysis of the metabolism of different organisms. Database URL: http://www.cycadsys.org.

  2. CycADS: an annotation database system to ease the development and update of BioCyc databases.

    PubMed

    Vellozo, Augusto F; Véron, Amélie S; Baa-Puyoulet, Patrice; Huerta-Cepas, Jaime; Cottret, Ludovic; Febvay, Gérard; Calevro, Federica; Rahbé, Yvan; Douglas, Angela E; Gabaldón, Toni; Sagot, Marie-France; Charles, Hubert; Colella, Stefano

    2011-01-01

    In recent years, genomes from an increasing number of organisms have been sequenced, but their annotation remains a time-consuming process. The BioCyc databases offer a framework for the integrated analysis of metabolic networks. The Pathway tool software suite allows the automated construction of a database starting from an annotated genome, but it requires prior integration of all annotations into a specific summary file or into a GenBank file. To allow the easy creation and update of a BioCyc database starting from the multiple genome annotation resources available over time, we have developed an ad hoc data management system that we called Cyc Annotation Database System (CycADS). CycADS is centred on a specific database model and on a set of Java programs to import, filter and export relevant information. Data from GenBank and other annotation sources (including for example: KAAS, PRIAM, Blast2GO and PhylomeDB) are collected into a database to be subsequently filtered and extracted to generate a complete annotation file. This file is then used to build an enriched BioCyc database using the PathoLogic program of Pathway Tools. The CycADS pipeline for annotation management was used to build the AcypiCyc database for the pea aphid (Acyrthosiphon pisum) whose genome was recently sequenced. The AcypiCyc database webpage includes also, for comparative analyses, two other metabolic reconstruction BioCyc databases generated using CycADS: TricaCyc for Tribolium castaneum and DromeCyc for Drosophila melanogaster. Linked to its flexible design, CycADS offers a powerful software tool for the generation and regular updating of enriched BioCyc databases. The CycADS system is particularly suited for metabolic gene annotation and network reconstruction in newly sequenced genomes. Because of the uniform annotation used for metabolic network reconstruction, CycADS is particularly useful for comparative analysis of the metabolism of different organisms. Database URL: http

  3. Investigation on heavy liquid metal cooling of ADS fuel pin assemblies

    NASA Astrophysics Data System (ADS)

    Litfin, K.; Batta, A.; Class, A. G.; Wetzel, Th.; Stieglitz, R.

    2011-08-01

    In the framework of accelerator driven sub-critical reactor systems heavy liquid metals are considered as coolant for the reactor core and the spallation target. In particular lead or lead bismuth eutectic (LBE) exhibit efficient heat removal properties and high production rate of neutrons. However, the excellent heat conductivity of LBE-flows expressed by a low molecular Prandtl number of the order 10 -2 requires improved modeling of the turbulent heat transfer. Although various models for thermal hydraulics of LBE flows are existing, validated heat transfer correlations for ADS-relevant conditions are still missing. In order to validate the sub-channel codes and computational fluid dynamics codes used to design fuel assemblies, the comparison with experimental data is inevitable. Therefore, an experimental program composed of three major experiments, a single electrically heated rod, a 19-pin hexagonal water rod bundle and a LBE rod bundle, has been initiated at the Karlsruhe Liquid metal Laboratory (KALLA) of the Karlsruhe Institute of Technology, in order to quantify and separate the individual phenomena occurring in the momentum and energy transfer of a fuel assembly.

  4. Value Added?

    ERIC Educational Resources Information Center

    UCLA IDEA, 2012

    2012-01-01

    Value added measures (VAM) uses changes in student test scores to determine how much "value" an individual teacher has "added" to student growth during the school year. Some policymakers, school districts, and educational advocates have applauded VAM as a straightforward measure of teacher effectiveness: the better a teacher, the better students…

  5. Irradiation conditions of ADS beam window and implications for window material

    NASA Astrophysics Data System (ADS)

    Vladimirov, P.; Möslang, A.

    2006-09-01

    Accelerator driven systems (ADS) are aimed at incineration of long living radioactive isotopes of spent nuclear reactor fuel, thus providing a solution for nuclear waste utilization. The idea is to couple a subcritical nuclear reactor with a high-energy proton accelerator. Protons interacting with the liquid metal target inside the reactor will produce neutrons with energy sufficient to transform long living fuel isotopes to those with shorter decay time. In some design variants a proton beam guide and window separate the vacuum of the accelerator from the liquid metal target. The window appears to be the most critical component of the whole facility as besides liquid metal corrosion it undergoes irradiation damage from incident protons, from protons and neutrons produced by spallation inside the target as well as from fission neutrons generated in the reactor fuel assemblies. In the present work we have evaluated irradiation conditions of the ADS beam window using Monte Carlo neutron, photon and charged particle transport code MCNPX. The code and the detailed geometric model of the experimental ADS (XADS) facility allow a realistic simulation of the spallation process and transport of generated nucleons as well as evaluation of various damage and operational characteristics like displacement damage, heat deposition, gas and spallation element production rates. Present results based on the reduced beam parameters provide a hope that apart from the liquid metal corrosion (not considered in the present paper) the window material could sustain full operation during the period of 3-4 month between replacements. These results may allow reconsideration of pro and contra of the window and the windowless XADS concepts.

  6. Simple system for measuring tritium Ad/absorption using a 2. pi. counter and thermal desorption spectrometer

    SciTech Connect

    Miyake, H.; Matsuyama, M.; Watanabe, K. ); Cowgill, D.F. )

    1992-03-01

    In this paper, the authors develop a simple system using tritium tracer and thermal desorption techniques to measure the tritium adsorption and/or absorption on/in a material having typical surface conditions: namely, not cleaned surface. The tritium counting devices used were a 2{pi} counter and conventional proportional counter. With this system, the amounts of ad/absorption could be measured without exposing the samples to air after exposing them to tritium gas. The overall efficiency (F) of the 2{pi} counter was described at F = exp({minus}2.64h), where h is the distance from the sample to the detector. Ad/absorption measurements were carried out for several materials used for fabricating conventional vacuum systems. The results were, in the order of decreasing amounts of ad/absorption, as (fiber reinforced plastics(FRP)) {gt} (nickel(Ni), molybdenum disulfide(MoS{sub 2})) {gt} (stainless steel (SS304), iron(Fe), aluminum alloy(A2219)) {gt} (boron nitride(h-BN), silicon carbide (SiC), SS304 passivated by anodic oxidation layers(ASS) and that by boron nitride segregation layers (BSS)). The relative amounts were abut 100 for Ni and 0.1 for ASS and BSS, being normalized to Fe = 1.

  7. A high performance, ad-hoc, fuzzy query processing system for relational databases

    NASA Technical Reports Server (NTRS)

    Mansfield, William H., Jr.; Fleischman, Robert M.

    1992-01-01

    Database queries involving imprecise or fuzzy predicates are currently an evolving area of academic and industrial research. Such queries place severe stress on the indexing and I/O subsystems of conventional database environments since they involve the search of large numbers of records. The Datacycle architecture and research prototype is a database environment that uses filtering technology to perform an efficient, exhaustive search of an entire database. It has recently been modified to include fuzzy predicates in its query processing. The approach obviates the need for complex index structures, provides unlimited query throughput, permits the use of ad-hoc fuzzy membership functions, and provides a deterministic response time largely independent of query complexity and load. This paper describes the Datacycle prototype implementation of fuzzy queries and some recent performance results.

  8. Fate of systemically administered cocaine in nonhuman primates treated with the dAd5GNE anticocaine vaccine.

    PubMed

    Hicks, Martin J; Kaminsky, Stephen M; De, Bishnu P; Rosenberg, Jonathan B; Evans, Suzette M; Foltin, Richard W; Andrenyak, David M; Moody, David E; Koob, George F; Janda, Kim D; Ricart Arbona, Rodolfo J; Lepherd, Michelle L; Crystal, Ronald G

    2014-03-01

    Cocaine use disorders are mediated by the cocaine blockade of the dopamine transporter in the central nervous system (CNS). On the basis of the concept that these effects could be obviated if cocaine were prevented from reaching its cognate receptors in the CNS, we have developed an anticocaine vaccine, dAd5GNE, based on a cocaine analog covalently linked to capsid proteins of an E1(-)E3(-) serotype 5 adenovirus. While the vaccine effectively blocks systemically administered cocaine from reaching the brain by mediating sequestration of the cocaine in the blood, the fact that cocaine also has significant peripheral effects raises concerns that vaccination-mediated redistribution could lead to adverse effects in the visceral organs. The distribution of systemically administered cocaine at a weight-adjusted typical human dose was evaluated along with cocaine metabolites in both dAd5GNE-vaccinated and control nonhuman primates. dAd5GNE sequestration of cocaine to the blood not only prevented cocaine access to the CNS, but also limited access of both the drug and its metabolites to other cocaine-sensitive organs. The levels of cocaine in the blood of vaccinated animals rapidly decreased, suggesting that while the antibody limits access of the drug and its active metabolites to the brain and sensitive organs of the periphery, it does not prolong drug levels in the blood compartment. Gross and histopathology of major organs found no vaccine-mediated untoward effects. These results build on our earlier measures of efficacy and demonstrate that the dAd5GNE vaccine-mediated redistribution of administered cocaine is not likely to impact the vaccine safety profile.

  9. Fate of Systemically Administered Cocaine in Nonhuman Primates Treated with the dAd5GNE Anticocaine Vaccine

    PubMed Central

    Hicks, Martin J.; Kaminsky, Stephen M.; De, Bishnu P.; Rosenberg, Jonathan B.; Evans, Suzette M.; Foltin, Richard W.; Andrenyak, David M.; Moody, David E.; Koob, George F.; Janda, Kim D.; Ricart Arbona, Rodolfo J.; Lepherd, Michelle L.

    2014-01-01

    Abstract Cocaine use disorders are mediated by the cocaine blockade of the dopamine transporter in the central nervous system (CNS). On the basis of the concept that these effects could be obviated if cocaine were prevented from reaching its cognate receptors in the CNS, we have developed an anticocaine vaccine, dAd5GNE, based on a cocaine analog covalently linked to capsid proteins of an E1−E3− serotype 5 adenovirus. While the vaccine effectively blocks systemically administered cocaine from reaching the brain by mediating sequestration of the cocaine in the blood, the fact that cocaine also has significant peripheral effects raises concerns that vaccination-mediated redistribution could lead to adverse effects in the visceral organs. The distribution of systemically administered cocaine at a weight-adjusted typical human dose was evaluated along with cocaine metabolites in both dAd5GNE-vaccinated and control nonhuman primates. dAd5GNE sequestration of cocaine to the blood not only prevented cocaine access to the CNS, but also limited access of both the drug and its metabolites to other cocaine-sensitive organs. The levels of cocaine in the blood of vaccinated animals rapidly decreased, suggesting that while the antibody limits access of the drug and its active metabolites to the brain and sensitive organs of the periphery, it does not prolong drug levels in the blood compartment. Gross and histopathology of major organs found no vaccine-mediated untoward effects. These results build on our earlier measures of efficacy and demonstrate that the dAd5GNE vaccine-mediated redistribution of administered cocaine is not likely to impact the vaccine safety profile. PMID:24649839

  10. Fate of systemically administered cocaine in nonhuman primates treated with the dAd5GNE anticocaine vaccine.

    PubMed

    Hicks, Martin J; Kaminsky, Stephen M; De, Bishnu P; Rosenberg, Jonathan B; Evans, Suzette M; Foltin, Richard W; Andrenyak, David M; Moody, David E; Koob, George F; Janda, Kim D; Ricart Arbona, Rodolfo J; Lepherd, Michelle L; Crystal, Ronald G

    2014-03-01

    Cocaine use disorders are mediated by the cocaine blockade of the dopamine transporter in the central nervous system (CNS). On the basis of the concept that these effects could be obviated if cocaine were prevented from reaching its cognate receptors in the CNS, we have developed an anticocaine vaccine, dAd5GNE, based on a cocaine analog covalently linked to capsid proteins of an E1(-)E3(-) serotype 5 adenovirus. While the vaccine effectively blocks systemically administered cocaine from reaching the brain by mediating sequestration of the cocaine in the blood, the fact that cocaine also has significant peripheral effects raises concerns that vaccination-mediated redistribution could lead to adverse effects in the visceral organs. The distribution of systemically administered cocaine at a weight-adjusted typical human dose was evaluated along with cocaine metabolites in both dAd5GNE-vaccinated and control nonhuman primates. dAd5GNE sequestration of cocaine to the blood not only prevented cocaine access to the CNS, but also limited access of both the drug and its metabolites to other cocaine-sensitive organs. The levels of cocaine in the blood of vaccinated animals rapidly decreased, suggesting that while the antibody limits access of the drug and its active metabolites to the brain and sensitive organs of the periphery, it does not prolong drug levels in the blood compartment. Gross and histopathology of major organs found no vaccine-mediated untoward effects. These results build on our earlier measures of efficacy and demonstrate that the dAd5GNE vaccine-mediated redistribution of administered cocaine is not likely to impact the vaccine safety profile. PMID:24649839

  11. Land-surface parameter optimisation using data assimilation techniques: the adJULES system V1.0

    NASA Astrophysics Data System (ADS)

    Raoult, Nina M.; Jupp, Tim E.; Cox, Peter M.; Luke, Catherine M.

    2016-08-01

    Land-surface models (LSMs) are crucial components of the Earth system models (ESMs) that are used to make coupled climate-carbon cycle projections for the 21st century. The Joint UK Land Environment Simulator (JULES) is the land-surface model used in the climate and weather forecast models of the UK Met Office. JULES is also extensively used offline as a land-surface impacts tool, forced with climatologies into the future. In this study, JULES is automatically differentiated with respect to JULES parameters using commercial software from FastOpt, resulting in an analytical gradient, or adjoint, of the model. Using this adjoint, the adJULES parameter estimation system has been developed to search for locally optimum parameters by calibrating against observations. This paper describes adJULES in a data assimilation framework and demonstrates its ability to improve the model-data fit using eddy-covariance measurements of gross primary production (GPP) and latent heat (LE) fluxes. adJULES also has the ability to calibrate over multiple sites simultaneously. This feature is used to define new optimised parameter values for the five plant functional types (PFTs) in JULES. The optimised PFT-specific parameters improve the performance of JULES at over 85 % of the sites used in the study, at both the calibration and evaluation stages. The new improved parameters for JULES are presented along with the associated uncertainties for each parameter.

  12. Integrated health care delivery system conducts ad agency search as part of its brand-launching effort.

    PubMed

    Lewicki, G

    1999-01-01

    PennState Geisinger Health System, Hershey, Pa., conducted an extensive ad agency search after its inception in 1997. The integrated health care delivery system needed to introduce its brand to an audience that was confused by the wide array of available health care options. BVK/McDonald, Milwaukee, the agency selected, has created a branding campaign that revolves around the tag-line "The power of health." PennState Geisinger will tabulate the results of BVK/McDonald's multi-million dollar campaign in 2000; at that time it will know whether its selection committee chose wisely.

  13. Evidence of active tectonics on a Roman aqueduct system (II-III century A.D.) near Rome, Italy

    NASA Astrophysics Data System (ADS)

    Marra, Fabrizio; Montone, Paola; Pirro, Mario; Boschi, Enzo

    2004-04-01

    In this paper we describe evidence of strong tectonic deformation affecting two aqueducts of Roman age (II-III century A.D.). The channels are located approximately 20 km northeast of Rome along the ancient Via Tiburtina. Brittle and ductile deformation affects these two structures, including extensional joint systems, NE-oriented faults, and horizontal distortion. This deformation is consistent with right-lateral movement on major N-striking faults, and represents the first evidence that tectonic deformation took place in historical times in the vicinity of Rome, with local strike-slip movement superimposed on a regional extensional fault system.

  14. A Time-Slotted On-Demand Routing Protocol for Mobile Ad Hoc Unmanned Vehicle Systems

    SciTech Connect

    Hope Forsmann; Robert Hiromoto; John Svoboda

    2007-04-01

    The popularity of UAVs has increased dramatically because of their successful deployment in military operations, their ability to preserve human life, and the continual improvements in wireless communication that serves to increase their capabilities. We believe the usefulness of UAVs would be dramatically increased if formation flight were added to the list of capabilities. Currently, sustained formation flight with a cluster of UAVs has only been achieved with two nodes by the Multi-UAV Testbed at the Massachusetts Institute of Technology. (Park, 2004) Formation flight is a complex operation requiring the ability to adjust the flight patterns on the fly and correct for wind gusts, terrain, and differences in node equipment. All of which increases the amount of inner node communication. Since one of the problems with MANET communication is network congestion, we believe a first step towards formation flight can be made through improved inner node communication. We have investigated current communication routing protocols and developed an altered hybrid routing protocol in order to provide communication with less network congestion.

  15. Adding Concrete Syntax to a Prolog-Based Program Synthesis System

    NASA Technical Reports Server (NTRS)

    Fischer, Bernd; Visser, Eelco

    2004-01-01

    Program generation and transformation systems work on two language levels, the object-level (i e., the language of the manipulated programs), and the meta-level (i.e., the implementation language of the system itself). The meta-level representations of object-level program fragments are usually built in an essentially syntax-free fashion using the operations provided by the meta-language. However, syntax matters and a large conceptual distance between the two languages makes it difficult to maintain and extend such systems. Here we describe how an existing Prolog-based system can gradually be retrofitted with concrete object-level syntax, thus shrinking this distance.

  16. Experimental verification of neutron phenomenology in lead and of transmutation by adiabatic resonance crossing in accelerator driven systems. A summary of the TARC Project at CERN

    NASA Astrophysics Data System (ADS)

    Abánades, A.; Aleixandre, J.; Andriamonje, S.; Angelopoulos, A.; Apostolakis, A.; Arnould, H.; Belle, E.; Bompas, C. A.; Brozzi, D.; Bueno, J.; Buono, S.; Carminati, F.; Casagrande, F.; Cennini, P.; Collar, J. I.; Cerro, E.; Del Moral, R.; Díez, S.; Dumps, L.; Eleftheriadis, C.; Embid, M.; Fernández, R.; Gálvez, J.; García, J.; Gelès, C.; Giorni, A.; González, E.; González, O.; Goulas, I.; Heuer, D.; Hussonnois, M.; Kadi, Y.; Karaiskos, P.; Kitis, G.; Klapisch, R.; Kokkas, P.; Lacoste, V.; Le Naour, C.; López, C.; Loiseaux, J. M.; Martínez-Val, J. M.; Méplan, O.; Nifenecker, H.; Oropesa, J.; Papadopoulos, I.; Pavlopoulos, P.; Pérez-Enciso, E.; Pérez-Navarro, A.; Perlado, M.; Placci, A.; Poza, M.; Revol, J.-P.; Rubbia, C.; Rubio, J. A.; Sakelliou, L.; Saldaña, F.; Savvidis, E.; Schussler, F.; Sirvent, C.; Tamarit, J.; Trubert, D.; Tzima, A.; Viano, J. B.; Vieira, S.; Vlachoudis, V.; Zioutas, K.

    2001-05-01

    The Transmutation by Adiabatic Resonance Crossing (TARC) experiment was carried out as PS211 at the CERN PS from 1996 to 1999. Energy and space distributions of spallation neutrons (produced by 2.5 and 3.57 GeV/ c CERN proton beams) slowing down in a 3.3×3.3×3 m 3 lead volume and neutron capture rates on long-lived fission fragments 99Tc and 129I demonstrate that Adiabatic Resonance Crossing (ARC) can be used to eliminate efficiently such nuclear waste and validate innovative simulation.

  17. Fuzzy inference systems, ASKE, knowledge value added, and Monte Carlo risk simulation for evaluating intangible human capital investments

    NASA Astrophysics Data System (ADS)

    Mun, Johnathan; de Albuquerque, Nelson R.; Liong, Choong-Yeun; Salleh, Abdul Razak

    2013-04-01

    This paper presents the ASKE-Risk method, coupled with Fuzzy Inference Systems, and Monte Carlo Risk Simulation to measure and prioritize Individual Technical Competence of a value chain to assess changes in the human capital of a company. ASKE is an extension of the method Knowledge Value Added, which proposes the use of a proxy variable for measuring the flow of knowledge used in a key process, creating a relationship between the company's financial results and the resources used in each of the business processes.

  18. Verification and validation guidelines for high integrity systems: Appendices A--D, Volume 2

    SciTech Connect

    Hecht, H,; Hecht, M.; Dinsmore, G.; Hecht, S.; Tang, D.

    1995-03-01

    The following material is furnished as an experimental guide for the use of risk based classification for nuclear plant protection systems. As shown in Sections 2 and 3 of this report, safety classifications for the nuclear field are application based (using the function served as the primary criterion), whereas those in use by the process industry and the military are risk based. There are obvious obstacles to the use of risk based classifications (and the associated integrity levels) for nuclear power plants, yet there are also many potential benefits, including: it considers all capabilities provided for dealing with a specific hazard, thus assigning a lower risk where multiple protection is provided (either at the same or at lower layers); this permits the plant management to perform trade-offs between systems that meet the highest qualification levels or multiple diverse systems at lower qualification levels; it motivates the use (and therefore also the development) of protection systems with demonstrated low failure probability; and it may permit lower cost process industry equipment of an established integrity level to be used in nuclear applications (subject to verification of the integrity level and regulatory approval). The totality of these benefits may reduce the cost of digital protection systems significantly an motivate utilities to much more rapid upgrading of the capabilities than is currently the case. Therefore the outline of a risk based classification is presented here, to serve as a starting point for further investigation and possible trial application.

  19. Performance Evaluation of Mobile Ad Hoc Network Based Communications for Future Mobile Tele-Emergency System

    NASA Astrophysics Data System (ADS)

    Viswacheda, D. V.; Barukang, L.; Hamid, M. Y.; Arifianto, M. S.

    Sparked by awareness of the limitations to provide medical services in remote areas, researchers have perceived that developing telemedicine systems is inevitable. In most cases very remote areas and disaster struck areas lack telecommunication infrastructure. Telemedicine system operating in such areas must have advanced wireless technology supporting it in devastating situation, hence it is called as tele-emergency system. Our approach is on MANET combined with Mobile IP and MIPV6, is the basis of infrastructure for the mobile tele-emergency system. The tele-emergency system requires data, voice and video transmission in its network. In this investigation, evaluation is based on simulation of the various ITU-T standard CODECs of VoIP and video transmission over MANET using discrete event simulator NS-2. The results of simulation showed that ITU-T G723.1 worked well in the MANET environment than the other CODECs for VoIP in fixed and mobility tele-emergency environments. From the simulation of video CODEC performance evaluation, it was observed that H.263 performed to a great extent in random small scale environment and also in multiple video flow of 57.6kbps speed video transmission.

  20. Adding Concrete Syntax to a Prolog-Based Program Synthesis System

    NASA Technical Reports Server (NTRS)

    Fischer, Bernd; Visser, Eelco

    2003-01-01

    Program generation and transformation systems manipulate large, pa- rameterized object language fragments. Support for user-definable concrete syntax makes this easier but is typically restricted to certain object and meta languages. We show how Prolog can be retrofitted with concrete syntax and describe how a seamless interaction of concrete syntax fragments with an existing legacy meta-programming system based on abstract syntax is achieved. We apply the approach to gradually migrate the schemas of the AUTOBAYES program synthesis system to concrete syntax. Fit experiences show that this can result in a considerable reduction of the code size and an improved readability of the code. In particular, abstracting out fresh-variable generation and second-order term construction allows the formulation of larger continuous fragments and improves the locality in the schemas.

  1. The diagram development for Computer Added Control and Monitoring system of drilling

    NASA Astrophysics Data System (ADS)

    Epikhin, A. V.; Mikhalev, R. S.; Anisimov, A. V.; Ulyanova, O. S.

    2015-11-01

    The paper is concerned with the first stage of the extensive research aimed at developing design-automation system and well drilling process control. The proposed system is going to have some advantages over modern analogues, such as economic analysis at all levels, active engineering staff feedback, precedent-related principle for recommendations, etc. It will essentially reduce the risk of human errors and also optimize the well construction process from design to commissioning. The paper considers the results of the first design stage in a form of flow diagrams.

  2. Adding Eyes: The Rise, Rewards, and Risks of Multi-Rater Teacher Observation Systems. Issue Brief

    ERIC Educational Resources Information Center

    White, Taylor

    2014-01-01

    New teacher evaluation systems have emerged as the cornerstone of the recent movement to improve public school teaching. Fueled by incentives from the federal government, state and local policymakers have sought to replace the often-cursory evaluation models of the past with more comprehensive ones. In contrast to past evaluations, which often…

  3. Combustion control system adding a liquid, exhaust gases, and PCV gases

    SciTech Connect

    Lindberg, J.E.

    1980-01-15

    A combustion control system is disclosed that adds a fluid and heat energy to the air-fuel mixture of the induction system of an internal combustion engine in response to engine need to improve combustion, to increase power, to improve efficiency, and to reduce emissions. The system incorporates fluidic control mechanisms which provide the control functions without any moving parts. The system incorporates one or more variable impedance flow control mechanisms, each of which produces an impedance to flow through the control mechanism which varies in a controlled relationship to the pressure differential across the control mechanism. In one embodiment, the main variable impedance control mechanism is a vortex chamber. The outlet of the vortex chamber is connected to the positive crankcase ventilation (PCV) inlet to intake manifold downstream of the butterfly valve. The vortex chamber has inputs for supplying air, the liquid, exhaust gases, and PCV gases for mixing within the vortex chamber. The incoming liquid, air, exhaust gases, and PCV gases are transmitted into the main vortex chamber by input constructions which, in themselves, provide for controlled regulation of both the relative proportions and total amounts of the incoming liquid and gases. In a specific embodiment, the input constructions include a liquid-exhaust gas acceleration chamber for mixing liquid with exhaust gases and a PCV-exhaust gas vortex chamber for mixing exhaust gases with PCV gases and air and swirl producing devices for causing controlled choking of the inlets of one or more of the vortex chambers. The system also incorporates a variable impedance syphon break in the line connecting the liquid source with the liquid-exhaust gas acceleration chamber.

  4. Cooling for SC devices of test cryomodule for ADS Injector II at IMP

    SciTech Connect

    Wang, L.; Wang, S. Y.; Sun, S.; Wang, S. H.; Liu, Y. Y.; Guo, X. L.

    2014-01-29

    The superconducting half-wave resonance cavities connected in series with superconducting solenoids will be applied to the Injector II of the Accelerator Driven Sub-critical System (ADS) to be built at the Modern Physics Institute, China. A test system has been developed for the purpose of performance test of the HWR cavities as well as validating the relevant technique for cooling the cavity and the solenoids together. It mainly comprises a cryogenic valve box (TVB), a test cryomodule (TCM1) and transfer lines. The TCM1 includes one HWR cavity, two superconducting solenoids, one cold BPM and their cooling system. The design of the TCM1 cryostat was carried out by the Shanghai Institute of Applied Physics (SINAP), CAS. Both the cavity and the solenoids will work at 4.4 K by bath cooling. The fast cooling down for the cavity from around 100 K to 120 K is required to avoid degrading of the cavity performance. After cool down and before energization, the solenoids should be warmed up to above 10 K and re-cooled down for the purpose of degaussing. The TCM1 can not only be cooled by using the dewar-filling system, but also operated by the refrigerator system. For the purpose of reducing the heat loads to the cold mass at 4 K from room temperature, thermal radiation shields cooled by liquid nitrogen flowing in tubing were employed. This paper presents the design details of cooling circuits and thermal shields of the TCM1 as well as related calculations and analyses.

  5. Dynamics of quadruple system Finsen 332 = ADS 11640 = Hip 92027 = WDS

    NASA Astrophysics Data System (ADS)

    Olevic, D.; Cvetkovic, Z.

    In 1829 Struve discovered a double star denoted as STF 2375 AB later on. Its separation was 2.2". It was noticed by Finsen from the Southern Observatory (Johannesburg) in 1953 that the components A and B are close binaries with separations about 0.15. The motion within this quadruple system - FIN 332 Aa and FIN 332 Bb - has been monitored from that time on. The data about the motion of these close binaries are analysed by the present authors and the preliminary orbital elements are calculated for each of them. The dynamical parallax from the obtained period and the semimajor axis for pair FIN 332 Bb agrees completely with that obtained from the Hipparcos programme. In the case of FIN 332 Aa a somewhat higher parallax, but within the error limits following from the errors of the period and semimajor axis, is obtained and it agrees with the parallax for FIN 332 Bb. The dynamical masses for the components of both systems are as expected for their spectral type A1V (all of them belong to the Main Sequence and here one uses Angelov's (1993) relation). According to our results, the motion of both systems takes place approximately in the same plane, confirming thus some general properties already noticed in the case of multiple stars.

  6. The BEHAVE-AD Assessment System: A Perspective, A Commentary on New Findings, and A Historical Review

    PubMed Central

    Reisberg, Barry; Monteiro, Isabel; Torossian, Carol; Auer, Stefanie; Shulman, Melanie B.; Ghimire, Santosh; Boksay, Istvan; BenArous, Francoise Guillo; Osorio, Ricardo; Vengassery, Aninditha; Imran, Sheema; Shaker, Hussam; Noor, Sadaf; Naqvi, Shazia; Kenowsky, Sunnie; Xu, Jinfeng

    2014-01-01

    Background Behavioral and psychological symptoms of dementia (BPSD) and associated disturbances in Alzheimer's disease (AD) are a source of distress and burden for spouses, professional caregivers, and others with responsibilities for the care of individuals with AD. BPSD with behavioral disturbances are also associated with more rapid institutionalization and increased morbidity and mortality for persons with AD. Objectives In this review and commentary, we discuss the history of the development of BPSD and behavioral disturbance assessments, which are distinct from those evaluating cognitive and functional symptoms of AD. In particular, we review the informant-based Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD), the related, potentially more sensitive, BEHAVE-AD Frequency-Weighted Severity Scale (BEHAVE-AD-FW), and the direct subject evaluation-based Empirical BEHAVE-AD Rating Scale (E-BEHAVE-AD). The kinds of medications that alleviate behavioral symptoms on these measures as well as the problems and possibilities for further advances with these medications are discussed. Finally, the importance of distinguishing BPSD and behavioral disturbance remediation in AD from the treatment of cognitive decline and other aspects of AD is emphasized in the context of appropriate assessment methodology. The objective of this paper is to provide a framework for further advances in the treatment of BPSD and associated behavioral disturbances in AD and, consequently, a framework for continuing improvements in the lives of individuals with AD and those who share the burden of the disease with the AD person. PMID:24714384

  7. The SAS Education Value-Added Assessment System (SAS[R] EVAAS[R]) in the Houston Independent School District (HISD): Intended and Unintended Consequences

    ERIC Educational Resources Information Center

    Amrein-Beardsley, Audrey; Collins, Clarin

    2012-01-01

    The SAS Educational Value-Added Assessment System (SAS[R] EVAAS[R]) is the most widely used value-added system in the country. It is also self-proclaimed as "the most robust and reliable" system available, with its greatest benefit to help educators improve their teaching practices. This study critically examined the effects of SAS[R] EVAAS[R] as…

  8. Molten salt fuels for treatment of plutonium and radwastes in ADS critical systems

    NASA Astrophysics Data System (ADS)

    Ignatiev, Victor V.

    2000-07-01

    Introduction of the innovative reactor concept of the incinerator type in the future nuclear power system should provide the following: • Low Plutonium and Minor Actinides Total Inventory in the Nuclear Fuel Cycle (M) • Reduced Actinides Total Losses to Waste (W) • Minimal Uranium-235 SupportMinimal Neutron Captures Outside Actinides (Coolant & Structural Material Activation Products). Estimations have shown strong dependence of the first two parameters (M and W), which are responsible for incinerator efficiency, from the burnup (c) reached in the core of an incinerator and the actinides mass flow rate in the fuel cycle (A(t)=G(t)/Q(t), where G(t)=amount of TRU fed to the process during t, and Q(t)=electricity produced during (t).

  9. [Application of over sampling sigma-delta A/D in DOAS system].

    PubMed

    Li, Su-wen; Liu, Wen-qing; Xie, Pin-hua

    2006-12-01

    Differential optical absorption spectroscopy (DOAS) has become a widely used method to measure trace gases in the atmosphere. Concentration of trace gases is retrieved using least-squares fits of reference spectra to the measurement spectra. The measurement precision not only depends on the measurement precision of spectra and the noise of instrument and disturbing of other gases in measuring band, but suffers the influence of signal sampling and pre-processing. The present paper simply introduced DOAS measuring principle and the setup of instrument and put forward improving method-the technology of over sampling sigma- deltaA/D. Using the sigma-delta modulator structure to shape noises together with the over sampling technology can doubly restrain quantifying noises, which can improve the signal-to-noise ratio within the measuring band. So the measurement precision of DOAS system is improved with this technology. PMID:17361733

  10. Radar systems for a polar mission, volume 3, appendices A-D, S, T

    NASA Technical Reports Server (NTRS)

    Moore, R. K.; Claassen, J. P.; Erickson, R. L.; Fong, R. K. T.; Hanson, B. C.; Komen, M. J.; Mcmillan, S. B.; Parashar, S. K.

    1976-01-01

    Success is reported in the radar monitoring of such features of sea ice as concentration, floe size, leads and other water openings, drift, topographic features such as pressure ridges and hummocks, fractures, and a qualitative indication of age and thickness. Scatterometer measurements made north of Alaska show a good correlation with a scattering coefficient with apparent thickness as deduced from ice type analysis of stereo aerial photography. Indications are that frequencies from 9 GHz upward seem to be better for sea ice radar purposes than the information gathered at 0.4 GHz by a scatterometer. Some information indicates that 1 GHz is useful, but not as useful as higher frequencies. Either form of like-polarization can be used and it appears that cross-polarization may be more useful for thickness measurement. Resolution requirements have not been fully established, but most of the systems in use have had poorer resolution than 20 meters. The radar return from sea ice is found to be much different than that from lake ice. Methods to decrease side lobe levels of the Fresnel zone-plate processor and to decrease the memory requirements of a synthetic radar processor are discussed.

  11. Identifying the types of waves: A value adding study on the ocean observing data buoy system

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, B.; Sannasiraj, S.; Sundar, V.

    2007-05-01

    Understanding of the wave climate in a particular place of interest is one of the primary aspects of any ocean observing system. Engineers and scientists working in the area of coastal or offshore engineering require to have knowledge on the types of waves that predominantly prevailing not only for the design of the ocean structures but also to understand the physical behavior of ocean surface. For example, identification of breaking waves is given prime importance as it has potential to answer for many of the water-air interaction or turbulence mixing problems. On the other hand, group of waves in which successive wave heights exceed the significant value could exert tremendous forces on the ocean structures and may lead catastrophic damage to it. Apart from deriving the conventional information such as the significant wave periods, heights and the predominant direction of prevailing, knowledge on the existence of type of waves would certainly help the designers, engineers and researchers. In an attempt to classify the types of waves from the buoy measurements, a detailed experimental program was conducted in the Department of Ocean Engineering, Indian Institute of Technology Madras. The buoy model was subjected to variety of waves such as group and breaking waves. The challenging task of the study is to simulate the group and breaking waves in the controlled laboratory environment. For which, initially, these waves are simulated theoretically, which intern converted into first order wave paddle signals to simulate the waves in the flume. The buoy heave, surge and pitch motions were measured by using potentiometers and the non-contact motion capturing cameras. The experimentally obtained wave elevation and the buoy motions time histories were analyzed by statistical, continuous wavelet transformation and phase-time methods to find the traces of wave types. A careful step by step analysis of the buoy motions yields presence of wave groupiness and breaking events

  12. Comparison of the Pharmacokinetics of Nicotine Following Single and Ad Libitum Use of a Tobacco Heating System or Combustible Cigarettes

    PubMed Central

    Picavet, Patrick; Haziza, Christelle; Lama, Nicola; Weitkunat, Rolf

    2016-01-01

    Introduction: We aimed to compare the pharmacokinetics of nicotine between the heat-not-burn Tobacco Heating System 2.1 (THS 2.1) and combustible cigarettes (CCs). We also examined whether the subjective urge to smoke was associated with the pharmacokinetics of nicotine. Methods: This open-label, randomized, two-period, two-sequence crossover study conducted in 28 healthy smokers assessed the pharmacokinetics of nicotine after single and ad libitum use of the THS 2.1 or CCs. During the 7-day confinement period, blood samples were drawn for pharmacokinetic analysis. Subjective effects related to THS 2.1 or CC use were assessed using the Questionnaire of Smoking Urges (QSU-Brief). Results: The nicotine delivery rate was similar with the THS 2.1 and CCs after single and ad libitum use. The time to the maximum nicotine concentration was 8 minutes after single use of the THS 2.1 and CCs. The time to the peak concentration following ad libitum use was similar between the THS 2.1 and CCs. The maximum plasma nicotine concentration after single use of the THS 2.1 was 8.4ng/mL, 70.3% of that obtained with CCs. A transient reduction from baseline in the urge to smoke of 40% was observed 15 minutes after the single use of both the THS 2.1 and CCs. The mean QSU-Brief total scores following single and ad libitum use were similar for the THS 2.1 and CCs. Conclusions: These results suggest that the THS 2.1 effectively delivers nicotine and achieves similar pharmacokinetic profiles to CCs. The THS 2.1 also reduced the urge to smoke similarly to CCs. Implications: Reducing exposure to toxicants and safer delivery of nicotine are among the strategies that may reduce the harm of smoking-related diseases. In the present study, we investigated the pharmacokinetics of nicotine and their effects on the urge to smoke using the THS 2.1. It was developed to replicate the ritual of smoking as closely as possible by providing nicotine in a way that mimics CC smoking, but limits pyrolysis and

  13. Early Identification and Systemic Educational Intervention for Young Children with Attention-Deficit/Hyperactivity Disorder (AD/HD)

    ERIC Educational Resources Information Center

    Brandau, Hannes; Pretis, Manfred

    2004-01-01

    This paper focuses on the international experience with early identification and intervention for children with AD/HD. Much less is known about AD/HD in two- to five-year-old preschool children than is known for older school-aged youngsters. Despite this lack of knowledge, AD/HD is increasingly recognized in this population and stimulant…

  14. Reactivation of the Pleistocene trans-Arabian Wadi ad Dawasir fluvial system (Saudi Arabia) during the Holocene humid phase

    NASA Astrophysics Data System (ADS)

    Matter, Albert; Mahjoub, Ayman; Neubert, Eike; Preusser, Frank; Schwalb, Antje; Szidat, Sönke; Wulf, Gerwin

    2016-10-01

    The Wadi ad Dawasir fluvial system in central Saudi Arabia is investigated using remote sensing and sedimentology, in combination with bio-proxy analyses (molluscs and ostracods). Age control is provided by radiocarbon as well as luminescence dating, using both quartz and feldspar grains. It is shown that the fluvial system was active from the Asir Mountains across the partially sand-covered interior of the Arabian Peninsula to the Arabian Gulf during the Holocene humid period. Sedimentology and faunal analysis reveal the presence of perennial streams and a permanent freshwater lake in the distal reach of the Dawasir system that are synchronous with fluvial accumulation in the headwaters of its major tributary, Wadi Tathlith. The increased runoff during the Holocene led to a re-activation of streams that largely followed pre-existing Late Pleistocene courses and eroded into older sediments. The absence of Holocene lakes in most of the Rub' al-Khali implies that trans-Arabian rivers were mainly fed by precipitation in the Asir Mountains. Monsoonal rainfall was apparently stronger there as well as in the northern, south-eastern and southern part of the Arabian Peninsula (southern Yemen and Oman), but it apparently did not directly affect the interior during the Holocene. The palaeoenvironmental reconstruction shows a narrow trans-Arabian green freshwater corridor as the result of phases of sustained flow lasting up to several centuries. The permanent availability of water and subsistence for wildlife provided a favourable environment for human occupation as documented by Neolithic stone tools that are found all along Wadi ad Dawasir.

  15. Positioning Accuracy in Stereotactic Radiotherapy Using a Mask System With Added Vacuum Mouth Piece and Stereoscopic X-Ray Positioning

    SciTech Connect

    Santvoort, Jan van Wiggenraad, Ruud; Bos, Petra

    2008-09-01

    Purpose: For cranial patients receiving stereotactic radiotherapy, we use the Exactrac stereoscopic X-ray system to optimize patient positioning. Patients are immobilized with the BrainLAB Mask System (BrainLAB, Feldkirchen, Germany). We have developed an adapter to this system that accommodates a vacuum mouth piece (VMP). Measurements with the Exactrac system have been performed to study the positioning accuracy after corrections with this system and to evaluate the accuracy of the VMP vs. the standard available upper jaw support (UJS). Methods and Materials: Positioning results were collected for 20 patients with the UJS and 20 patients with the VMP, before treatment (1,122 fractions) and after treatment (400 fractions). For all 6 degrees of freedom the average, the random error and systematic error were calculated. Results: The average vector length before and after correction with the Exactrac system was 2.1 {+-} 1.2 mm and 0.7 {+-} 0.6 mm respectively for UJS and 1.7 {+-} 0.7 mm and 0.4 {+-} 0.4 mm for VMP. Interfraction positioning for translations was greatly improved after correction with the Exactrac system (p < 0.0005) and is better with VMP than with UJS (p = 0.005). Outliers were greatly reduced. Interfraction rotations were significantly smaller for VMP. Intrafraction errors for vertical and longitudinal translations and for rotations were smaller for the VMP. Conclusions: Positioning correction using the Exactrac X-ray system greatly improves accuracy. Adding the VMP results in even better patient fixation and smaller rotations, making it a useful addition to the Mask System. Combined, this is a convenient and accurate alternative to invasive fixation methods.

  16. Behavioral Risk Factor Surveillance System State-Added Questions: Leveraging an Existing Surveillance System to Improve Knowledge of Women's Reproductive Health.

    PubMed

    Boulet, Sheree L; Warner, Lee; Adamski, Alys; Smith, Ruben A; Burley, Kim; Grigorescu, Violanda

    2016-06-01

    As the prevalence of chronic conditions among women of reproductive age continues to rise, studies assessing the intersection of chronic disease and women's reproductive health status are increasingly needed. However, many data systems collect only limited information on women's reproductive health, thereby hampering the appraisal of risk and protective factors across the life span. One way to expand the study of women's health with minimal investment in time and resources is to integrate questions on reproductive health into existing surveillance systems. In 2013, previously validated questions on women's self-reported reproductive history, use of contraception, and infertility were added to the Behavioral Risk Factor Surveillance System (BRFSS) by seven states (Connecticut, Kentucky, Massachusetts, Mississippi, Ohio, Texas, and Utah); all female respondents aged 18-50 years were included in the pool of respondents for these state-added questions. Of 8691 women who completed the questions, 13.2% reported ever experiencing infertility and 59.8% of those at risk for unintended pregnancy reported using contraception at last intercourse. The information garnered from the state-added reproductive health questions can be augmented with the BRFSS core questions on health-related risk behaviors, chronic conditions, and use of preventive services. Expanding existing data collection systems with supplemental questions on women's reproductive health can provide important information on risk factors and outcomes that may not be available from other sources. PMID:27227657

  17. DIS in AdS

    SciTech Connect

    Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios

    2009-03-23

    We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS{sub 5}. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS{sub 5} shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Q{sub s} is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Q{sub s}{approx}A{sup 1/3}. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of {alpha}{sub P} = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of {alpha}{sub P} = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be {alpha}{sub P} = 1.5.

  18. Separation of no-carrier-added rhenium from bulk tantalum by the sodium malonate-PEG aqueous biphasic system.

    PubMed

    Dutta, Binita; Lahiri, Susanta; Tomar, B S

    2014-02-01

    The aqueous biphasic system (ABS) involving sodium malonate-polyethylene glycol (PEG) phases has been applied for the first time for separation of no-carrier-added (183)Re (T1/2=70 d) from α-particle irradiated bulk tantalum target. The various ABS conditions were applied for investigating the separation by varying pH, temperature, PEG-molecular weight, concentration of salt. The extraction pattern was hardly affected by change in pH and the molecular weight of PEG. One step separation of nca (183)Re from Ta was achieved at the optimal conditions of (i) 50% (w/w) PEG-4000-2 M sodium malonate, 40 °C and (ii) 50% (w/w) PEG-4000-3 M sodium malonate, room temperature (27 °C).

  19. ADS pilot program Plan

    NASA Technical Reports Server (NTRS)

    Clauson, J.; Heuser, J.

    1981-01-01

    The Applications Data Service (ADS) is a system based on an electronic data communications network which will permit scientists to share the data stored in data bases at universities and at government and private installations. It is designed to allow users to readily locate and access high quality, timely data from multiple sources. The ADS Pilot program objectives and the current plans for accomplishing those objectives are described.

  20. An experimental seasonal hydrological forecasting system over the Yellow River basin - Part 2: The added value from climate forecast models

    NASA Astrophysics Data System (ADS)

    Yuan, Xing

    2016-06-01

    This is the second paper of a two-part series on introducing an experimental seasonal hydrological forecasting system over the Yellow River basin in northern China. While the natural hydrological predictability in terms of initial hydrological conditions (ICs) is investigated in a companion paper, the added value from eight North American Multimodel Ensemble (NMME) climate forecast models with a grand ensemble of 99 members is assessed in this paper, with an implicit consideration of human-induced uncertainty in the hydrological models through a post-processing procedure. The forecast skill in terms of anomaly correlation (AC) for 2 m air temperature and precipitation does not necessarily decrease over leads but is dependent on the target month due to a strong seasonality for the climate over the Yellow River basin. As there is more diversity in the model performance for the temperature forecasts than the precipitation forecasts, the grand NMME ensemble mean forecast has consistently higher skill than the best single model up to 6 months for the temperature but up to 2 months for the precipitation. The NMME climate predictions are downscaled to drive the variable infiltration capacity (VIC) land surface hydrological model and a global routing model regionalized over the Yellow River basin to produce forecasts of soil moisture, runoff and streamflow. And the NMME/VIC forecasts are compared with the Ensemble Streamflow Prediction method (ESP/VIC) through 6-month hindcast experiments for each calendar month during 1982-2010. As verified by the VIC offline simulations, the NMME/VIC is comparable to the ESP/VIC for the soil moisture forecasts, and the former has higher skill than the latter only for the forecasts at long leads and for those initialized in the rainy season. The forecast skill for runoff is lower for both forecast approaches, but the added value from NMME/VIC is more obvious, with an increase of the average AC by 0.08-0.2. To compare with the observed

  1. Role of ADS in the back-end of the fuel cycle strategies and associated design activities: The case of Japan

    NASA Astrophysics Data System (ADS)

    Oigawa, Hiroyuki; Tsujimoto, Kazufumi; Nishihara, Kenji; Sugawara, Takanori; Kurata, Yuji; Takei, Hayanori; Saito, Shigeru; Sasa, Toshinobu; Obayashi, Hironari

    2011-08-01

    Reduction of burden caused by radioactive waste management is one of the most critical issues for the sustainable utilization of nuclear power. The Partitioning and Transmutation (P&T) technology provides the possibility to reduce the amount of the radiotoxic inventory of the high-level radioactive waste (HLW) dramatically and to extend the repository capacity. The accelerator-driven system (ADS) is regarded as a powerful tool to effectively transmute minor actinides (MAs) in the "double-strata" fuel cycle strategy. The ADS has a potential to flexibly manage MA in the transient phase from light water reactors (LWRs) to fast breeder reactors (FBRs), and can co-exist with FBR symbiotically and complementarily to enhance the reliability and the safety of the commercial FBR cycle. The concept of ADS in JAEA is a lead-bismuth eutectic (LBE) cooled, tank-type subcritical reactor with the power of 800 MWth driven by a 30 MW superconducting LINAC. By such an ADS, 250 kg of MA can be transmuted annually, which corresponds to the amount of MA produced in 10 units of LWR with 1 GWe. The design study was performed mainly for the subcritical reactor and the spallation target with a beam window. In Japan, Atomic Energy Commission (AEC) has implemented the check and review (C&R) on P&T technology from 2008 to 2009. In the C&R, the benefit of P&T technology, the current status of the R&D, and the way forward to promote it were discussed.

  2. A Proposal and Evaluation of Security Camera System at a Car Park in an Ad-Hoc Network

    NASA Astrophysics Data System (ADS)

    Uemura, Wataru; Murata, Masashi

    In recent year, ad-hoc network technology has gained attention, which consists of not access points and base stations but of wireless nodes. In this network, it is difficult to maintain the whole data flow because of the absence of access points as the network administrator when nodes share the data. This paper proposes the security camera system which has only nodes sharing the taken pictures and has the robustness against the data destroying. The sender node cannot know whether packets are received or not by neighboring nodes in broadcasting because of a unidirectional communication. So in our proposed method, the sender node selects the receiver node from neighboring nodes, and they communicate with each other. On the other hand, neighboring nodes listen to packets between the sender node and the receiver node. After that, this method guarantees nodes of more than 1 which receive a data in broadcasting. We construct the security camera system using wireless nodes with the IEEE 802.15.4 specification and show the performance for security. At last, using the simulator we show the efficiency in the large environment, and conclude this paper.

  3. Dressing phases of AdS3/CFT2

    NASA Astrophysics Data System (ADS)

    Borsato, Riccardo; Ohlsson Sax, Olof; Sfondrini, Alessandro; Stefański, Bogdan, Jr.; Torrielli, Alessandro

    2013-09-01

    We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3×S3×T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their subleading order and compare it with recent one-loop perturbative results and comment on their weak-coupling expansion.

  4. Enhanced Gene Detection Assays for Fumarate-Adding Enzymes Allow Uncovering of Anaerobic Hydrocarbon Degraders in Terrestrial and Marine Systems

    PubMed Central

    von Netzer, Frederick; Pilloni, Giovanni; Kleindienst, Sara; Krüger, Martin; Knittel, Katrin; Gründger, Friederike

    2013-01-01

    The detection of anaerobic hydrocarbon degrader populations via catabolic gene markers is important for the understanding of processes at contaminated sites. Fumarate-adding enzymes (FAEs; i.e., benzylsuccinate and alkylsuccinate synthases) have already been established as specific functional marker genes for anaerobic hydrocarbon degraders. Several recent studies based on pure cultures and laboratory enrichments have shown the existence of new and deeply branching FAE gene lineages, such as clostridial benzylsuccinate synthases and homologues, as well as naphthylmethylsuccinate synthases. However, established FAE gene detection assays were not designed to target these novel lineages, and consequently, their detectability in different environments remains obscure. Here, we present a new suite of parallel primer sets for detecting the comprehensive range of FAE markers known to date, including clostridial benzylsuccinate, naphthylmethylsuccinate, and alkylsuccinate synthases. It was not possible to develop one single assay spanning the complete diversity of FAE genes alone. The enhanced assays were tested with a range of hydrocarbon-degrading pure cultures, enrichments, and environmental samples of marine and terrestrial origin. They revealed the presence of several, partially unexpected FAE gene lineages not detected in these environments before: distinct deltaproteobacterial and also clostridial bssA homologues as well as environmental nmsA homologues. These findings were backed up by dual-digest terminal restriction fragment length polymorphism diagnostics to identify FAE gene populations independently of sequencing. This allows rapid insights into intrinsic degrader populations and degradation potentials established in aromatic and aliphatic hydrocarbon-impacted environmental systems. PMID:23124238

  5. Effects of CX3CR1 and Fractalkine Chemokines in Amyloid Beta Clearance and p-Tau Accumulation in Alzheimer's Disease (AD) Rodent Models: Is Fractalkine a Systemic Biomarker for AD?

    PubMed

    Merino, José Joaquín; Muñetón-Gómez, Vilma; Alvárez, María-Isabel; Toledano-Díaz, Adolfo

    2016-01-01

    Microglia and astrocytes are the major source of cytokines in Alzheimer,s disease (AD). CX3CR1 is a delta chemokine receptor found in microglia and its neuronal ligand, Fractalkine, has two isoforms: an anchored-membrane isoform, and a soluble isoform. The reduced soluble fractalkine levels found in the brain (cortex/hippocampus) of aged rats, may be a consequence of neuronal loss. This soluble fractalkine maintains microglia in an appropiate state by interacting with CX3CR1. The ablation of the CX3CR1 gene in mice overexpressing human amyloid precursor protein (APP/PS-1) increased cytokine levels, enhanced Tau pathology and worsened behavioural performance in these mice. However, CX3CR1 deficiency resulted in a gene dose-dependent Aβ clearance in the brain, and induced microglial activation. In addition, CX3CR1 deficiency can have benefical effects by preventing neuronal loss in the 3xTg model. In fact, CX3CR1 deficiency increases microglial phagocytosome activity by inducing selective protofibrillar amyloid-beta phagocytosis in microglial cells in transgenic AD models. On the other hand, the fractalkine membrane isoform plays a differential role in amyloid beta clearance and Tau deposition. This anchored membrane FKN signalling might increase amyloid pathology while soluble fractalkine levels could prevent taupathies. However, in human AD, the only published study has reported higher systemic fractalkine levels in AD patients with cognitive impairment. In mouse models, inflammatory activation of microglia accelerates Tau pathology. Studies in transgenic mice with fractalkine null mice suggest that APP/PS-1 mice deficient for the anchored membrane-fractalkine isoform exhibited enhanced neuronal MAPT phosphorylation despite their reduced amyloid burden. The soluble fractalkine overexpression with adenoviral vectors reduced tau pathology and prevented neurodegeneration in a Tg4510 model of taupathy Finally, animals with Aβ (1-42) infused by lentivirus (cortex) or

  6. Systems biology network-based discovery of a small molecule activator BL-AD008 targeting AMPK/ZIPK and inducing apoptosis in cervical cancer

    PubMed Central

    Tong, Xupeng; Zhang, Jin; Zhang, Yonghui; Ouyang, Liang; Liu, Bo; Huang, Jian

    2015-01-01

    The aim of this study was to discover a small molecule activator BL-AD008 targeting AMPK/ZIPK and inducing apoptosis in cervical cancer. In this study, we systematically constructed the global protein-protein interaction (PPI) network and predicted apoptosis-related protein connections by the Naïve Bayesian model. Then, we identified some classical apoptotic PPIs and other previously unrecognized PPIs between apoptotic kinases, such as AMPK and ZIPK. Subsequently, we screened a series of candidate compounds targeting AMPK/ZIPK, synthesized some compounds and eventually discovered a novel dual-target activator (BL-AD008). Moreover, we found BL-AD008 bear remarkable anti-proliferative activities toward cervical cancer cells and could induce apoptosis by death-receptor and mitochondrial pathways. Additionally, we found that BL-AD008-induced apoptosis was affected by the combination of AMPK and ZIPK. Then, we found that BL-AD008 bear its anti-tumor activities and induced apoptosis by targeting AMPK/ZIPK in vivo. In conclusion, these results demonstrate the ability of systems biology network to identify some key apoptotic kinase targets AMPK and ZIPK; thus providing a dual-target small molecule activator (BL-AD008) as a potential new apoptosis-modulating drug in future cervical cancer therapy. PMID:25797270

  7. Nonclassical properties and purity of a qubit system in photon-added squeezed thermal states with time-dependent coupling effect

    NASA Astrophysics Data System (ADS)

    Berrada, K.; Abdel-Khalek, S.

    2016-10-01

    The degree of purity and nonclassical properties for a two-level system interacting with a photon-added squeezed thermal field (PASTF) are described in terms of the physical parameters involved in the whole system state with and without time-dependent coupling effect. Specially, we investigate the influence of the squeezed parameter and photon-added number on the behavior of the linear entropy and the Mandel's parameter. We find that for each value of the photon-added number, there exist critical value of the squeezed parameter for which the linear entropy is maximal and the statistical properties get farther from the trivial case. Moreover, we show that the presence of the time-dependent coupling effect may increase the periodicity time and lead to quench oscillations of the Mandel's parameter during the evolution. Finally, we exploit an interesting relationship between the linear entropy and the Mandel's parameter in terms of the physical parameters.

  8. Generation and pointing stabilization of multi-GeV electron beams from a laser plasma accelerator driven in a pre-formed plasma waveguide

    SciTech Connect

    Gonsalves, A. J.; Nakamura, K.; Daniels, J.; Mao, H.-S.; Benedetti, C.; Schroeder, C. B.; Tóth, Cs.; Tilborg, J. van; Vay, J.-L.; Geddes, C. G. R.; Esarey, E.; Mittelberger, D. E.; Bulanov, S. S.; Leemans, W. P.

    2015-05-15

    Laser pulses with peak power 0.3 PW were used to generate electron beams with energy >4 GeV within a 9 cm-long capillary discharge waveguide operated with a plasma density of ≈7×10{sup 17} cm{sup −3}. Simulations showed that the super-Gaussian near-field laser profile that is typical of high-power femtosecond laser systems reduces the efficacy of guiding in parabolic plasma channels compared with the Gaussian laser pulses that are typically simulated. In the experiments, this was mitigated by increasing the plasma density and hence the contribution of self-guiding. This allowed for the generation of multi-GeV electron beams, but these had angular fluctuation ≳2 mrad rms. Mitigation of capillary damage and more accurate alignment allowed for stable beams to be produced with energy 2.7±0.1 GeV. The pointing fluctuation was 0.6 mrad rms, which was less than the beam divergence of ≲1 mrad full-width-half-maximum.

  9. Natural removal of added N-nutrients, reactive phosphorus, crude oil, and heavy metals from the water phase in a simulated water/sediment system

    SciTech Connect

    Lam-Leung, S.Y.; Cheung, M.T.; He, Y.Q.

    1996-08-01

    Water/sediment simulation systems were constructed by using an aquarium (0.45 x 0.29 x 0.35 m{sup 3}), filled with suitable amounts of water and sediment collected from three selected locations: Lan Hau Shan (LHS), Tai Hu (TH), and Loong Yu Tao (LYT) of the Zhujiang (Pearl River) Estuary of China in November 1992 at low-tide period. The salinities of the water samples collected form LHS, TH, LYT were found to be 0.2, 4.6, 16.2 g L{sup -1}, respectively. Known amounts of ammonium, nitrate, nitrite, reactive phosphorous, crude oil, arsenate(III), cadmium (II), copper(II), and zinc(II) were added as pollutants into each of the water/sediment simulation systems. The rates of the natural removal of each added pollutant in all water/sediment simulation systems were studied by monitoring their concentrations at various intrevals in the investigation period. Except for Cr(III) and reactive phosphorous in the water/sediment systems of the LHS, TH, and LYT sites, and nitrate in the TH and LYT sites, the concentrations of the added pollutants in the water phase of the studied systems under a flow-condition simulation were reduced to 8% or less of the corresponding added amount on or before the 12th day by natural processes. The rate of self-purification and the estimated assimulative capacity of each added pollutant in all water/sediment simulation systems is discussed. 30 refs., 11 figs., 4 tabs.

  10. Houston, We Have a Problem: Studying the SAS Education Value-Added Assessment System (EVAAS) from Teachers' Perspectives in the Houston Independent School District (HISD)

    ERIC Educational Resources Information Center

    Collins, Clarin

    2012-01-01

    This study examined the intended and unintended consequences associated with the Education Value-Added Assessment System (EVAAS) as perceived and experienced by teachers in the Houston Independent School District (HISD). To evaluate teacher effectiveness, HISD is using EVAAS for high-stakes consequences more than any other district or state in the…

  11. Miniature accelerator-driven gamma source concept.

    SciTech Connect

    Garnett, R. W.; Chan, K. D.; Wangler, Thomas P.,; Wood R. L.; Carlsten, B. E.; Kirbie, H. C.

    2003-01-01

    Recent developments in W-band (-100 GHz) traveling wave tube technology at Los Alarnos may lead to a compact high-power W-band RE source. A conceptual design of a compact 8-MeV electron linac that codd be powered by this source is presented, including electromagnetic structure calculations, proposed rnicrojbbrication and manufacturing methods, supporting calculations to estimate accelerator performance, and gumma production rates based on preliminary target geometries and expected output beam current.

  12. Accelerator-driven boron neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Edgecock, Rob

    2014-05-01

    Boron Neutron Capture Therapy is a binary treatment for certain types of cancer. It works by loading the cancerous cells with a boron-10 carrying compound. This isotope has a large cross-section for thermal neutrons, the reaction producing a lithium nucleus and alpha particle that kill the cell in which they are produced. Recent studies of the boron carrier compound indicate that the uptake process works best in particularly aggressive cancers. Most studied is glioblastoma multiforme and a trial using a combination of BNCT and X-ray radiotherapy has shown an increase of nearly a factor of two in mean survival over the state of the art. However, the main technical problem with BNCT remains producing a sufficient flux of neutrons for a reasonable treatment duration in a hospital environment. This paper discusses this issue.

  13. Segmented strings in AdS 3

    NASA Astrophysics Data System (ADS)

    Callebaut, Nele; Gubser, Steven S.; Samberg, Andreas; Toldo, Chiara

    2015-11-01

    We study segmented strings in flat space and in AdS 3. In flat space, these well known classical motions describe strings which at any instant of time are piecewise linear. In AdS 3, the worldsheet is composed of faces each of which is a region bounded by null geodesics in an AdS 2 subspace of AdS 3. The time evolution can be described by specifying the null geodesic motion of kinks in the string at which two segments are joined. The outcome of collisions of kinks on the worldsheet can be worked out essentially using considerations of causality. We study several examples of closed segmented strings in AdS 3 and find an unexpected quasi-periodic behavior. We also work out a WKB analysis of quantum states of yo-yo strings in AdS 5 and find a logarithmic term reminiscent of the logarithmic twist of string states on the leading Regge trajectory.

  14. Influence of different types and proportions of added edible seaweeds on characteristics of low-salt gel/emulsion meat systems.

    PubMed

    Cofrades, S; López-López, I; Solas, M T; Bravo, L; Jiménez-Colmenero, F

    2008-08-01

    The effects of three different types of edible seaweeds, Sea Spaghetti (Himanthalia elongata), Wakame (Undaria pinnatifida), and Nori (Porphyra umbilicalis) added at two concentrations (2.5% and 5% dry matter) on the physicochemical and morphological characteristics of gel/emulsion systems were evaluated. The addition of seaweeds improved (P<0.05) water- and fat-binding properties except in the case of Nori added at 2.5%. Hardness and chewiness of the cooked products with added seaweed were higher (P<0.05), and springiness and cohesiveness were lower (P<0.05) than in control samples. Colour changes in meat systems were affected by the type of seaweed. The morphology of sample differed depending on the type of seaweed added, and this is the result of differences in physical and chemical characteristic of the seaweed powder used. In general, products formulated with the brown seaweeds (Sea Spaghetti and Wakame) exhibited similar behaviour, different from that of products made with the red seaweed Nori. PMID:22063041

  15. The Internet and healthcare in Taiwan: value-added applications on the medical network in the National Health Insurance smart card system.

    PubMed

    Tsai, Wen-Hsien; Kuo, Hsiao-Chiao

    2007-01-01

    The introduction of smart card technology has ushered in a new era of electronic medical information systems. Taiwan's Bureau of National Health Insurance (BNHI) implemented the National Health Insurance (NHI) smart card project in 2004. The purpose of the project was to replace all paper cards with one smart card. The NHI medical network now provides three kinds of services. In this paper, we illustrate the status of the NHI smart card system in Taiwan and propose three kinds of value-added applications for the medical network, which are electronic exchange of medical information, retrieval of personal medical records and medical e-learning for future development of health information systems.

  16. An effective method for enhancing metal-ions' selectivity of ionic liquid-based extraction system: Adding water-soluble complexing agent.

    PubMed

    Sun, Xiao Qi; Peng, Bo; Chen, Ji; Li, De Qian; Luo, Fang

    2008-01-15

    Selective extraction-separation of yttrium(III) from heavy lanthanides into 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)mim][PF(6)]) containing Cyanex 923 was achieved by adding a water-soluble complexing agent (EDTA) to aqueous phase. The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of [C(n)mim][PF(6)]/[Tf(2)N]-based extraction system without increasing the loss of [C(n)mim](+).

  17. 1 GeV CW nonscaling FFAG for ADS, and magnet parameters

    SciTech Connect

    Johnstone C.; Meot, F.; Snopok, P.; Weng, W.

    2012-05-20

    Multi-MW proton driver capability remains a challenging, critical technology for many core HEP programs, particularly the neutrino ones such as the Muon Collider and Neutrino factory, and for high-profile energy applications such as Accelerator Driven Subcritical Reactors (ADS) and Accelerator Transmutation of Waste for nuclear power and waste management. Work is focused almost exclusively on an SRF linac, as, to date, no re-circulating accelerator can attain the 10-20 MW capability necessary for the nuclear applications. Recently, the concept of isochronous orbits has been explored and developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. Work is progressing on a stable, high-intensity, 1 GeV isochronous FFAG. Initial specifications of novel magnets with the nonlinear radial fields required to support isochronous operation are also reported here.

  18. AdS duals of matrix strings

    NASA Astrophysics Data System (ADS)

    Morales, Jose F.; Samtleben, Henning

    2003-06-01

    We review recent work on the holographic duals of type II and heterotic matrix string theories described by warped AdS3 supergravities. In particular, we compute the spectra of Kaluza-Klein primaries for type I, II supergravities on warped AdS3 × S7 and match them with the primary operators in the dual two-dimensional gauge theories. The presence of non-trivial warp factors and dilaton profiles requires a modification of the familiar dictionary between masses and 'scaling' dimensions of fields and operators. We present these modifications for the general case of domain wall/QFT correspondences between supergravities on warped AdSd+1 × Sq geometries and super Yang-Mills theories with 16 supercharges.

  19. Electrical conductivity of a system of Ag2SO4:AgI eutectic added to 30Li2SO4:70Ag2SO4

    NASA Astrophysics Data System (ADS)

    Chandrayan, V. R.; Tejpal, A.; Singh, K.

    1989-10-01

    The electrical conductivity of rapidly quenched specimens of 48Ag2SO4:52AgI eutectic added to 30Li2SO4:70Ag2SO4 has been measured as a function of frequency and temperature. The results show a significant enhancement in the conductivity of the 30Li2SO4:70Ag2SO4 system with a maximum value at 12.5 mol. pct eutectic. This phenomenon is explained in terms of the dispersive nature of the fine eutectic crystallites in the crystalline matrix of the Li2SO4:Ag2SO4 system.

  20. Development of an intelligent interface for adding spatial objects to a knowledge-based geographic information system

    NASA Technical Reports Server (NTRS)

    Campbell, William J.; Goettsche, Craig

    1989-01-01

    Earth Scientists lack adequate tools for quantifying complex relationships between existing data layers and studying and modeling the dynamic interactions of these data layers. There is a need for an earth systems tool to manipulate multi-layered, heterogeneous data sets that are spatially indexed, such as sensor imagery and maps, easily and intelligently in a single system. The system can access and manipulate data from multiple sensor sources, maps, and from a learned object hierarchy using an advanced knowledge-based geographical information system. A prototype Knowledge-Based Geographic Information System (KBGIS) was recently constructed. Many of the system internals are well developed, but the system lacks an adequate user interface. A methodology is described for developing an intelligent user interface and extending KBGIS to interconnect with existing NASA systems, such as imagery from the Land Analysis System (LAS), atmospheric data in Common Data Format (CDF), and visualization of complex data with the National Space Science Data Center Graphics System. This would allow NASA to quickly explore the utility of such a system, given the ability to transfer data in and out of KBGIS easily. The use and maintenance of the object hierarchies as polymorphic data types brings, to data management, a while new set of problems and issues, few of which have been explored above the prototype level.

  1. Removal of added nitrate in the single, binary, and ternary systems of cotton burr compost, zerovalent iron, and sediment: Implications for groundwater nitrate remediation using permeable reactive barriers.

    PubMed

    Su, Chunming; Puls, Robert W

    2007-04-01

    Recent research has shown that carbonaceous solid materials and zerovalent iron (Fe(0)) may potentially be used as media in permeable reactive barriers (PRBs) to degrade groundwater nitrate via heterotrophic denitrification in the solid carbon system, and via abiotic reduction and autotrophic denitrification in the Fe(0) system. Questions arise as whether the more expensive Fe(0) is more effective than the less expensive carbonaceous solid materials for groundwater nitrate remediation, and whether there is any synergistic effect of mixing the two different types of materials. We carried out batch tests to study the nature and rates of removal of added nitrate in the suspensions of single, binary, and ternary systems of cotton burr compost, Peerless Fe(0), and a sediment low in organic carbon. Cotton burr compost acted as both organic carbon source and supporting material for the growth of indigenous denitrifiers. Batch tests showed that cotton burr compost alone removed added nitrate at a greater rate than did Peerless Fe(0) alone on an equal mass basis with a pseudo-first-order rate constant k=0.0830+/-0.0031 h(-1) for cotton burr compost and a k=0.00223+/-0.00022 h(-1) for Peerless Fe(0); cotton burr compost also removed added nitrate at a faster rate than did cotton burr compost mixed with Peerless Fe(0) and/or the sediment. Furthermore, there was no substantial accumulation of ammonium ions in the cotton burr compost system, in contrast to the systems containing Peerless Fe(0) in which ammonium ions persisted as major products of nitrate reduction. It is concluded that cotton burr compost alone may be used as an excellent denitrification medium in a PRB for groundwater nitrate removal. Further study is needed to evaluate performance of its field applications. PMID:17257645

  2. Removal of added nitrate in the single, binary, and ternary systems of cotton burr compost, zerovalent iron, and sediment: Implications for groundwater nitrate remediation using permeable reactive barriers.

    PubMed

    Su, Chunming; Puls, Robert W

    2007-04-01

    Recent research has shown that carbonaceous solid materials and zerovalent iron (Fe(0)) may potentially be used as media in permeable reactive barriers (PRBs) to degrade groundwater nitrate via heterotrophic denitrification in the solid carbon system, and via abiotic reduction and autotrophic denitrification in the Fe(0) system. Questions arise as whether the more expensive Fe(0) is more effective than the less expensive carbonaceous solid materials for groundwater nitrate remediation, and whether there is any synergistic effect of mixing the two different types of materials. We carried out batch tests to study the nature and rates of removal of added nitrate in the suspensions of single, binary, and ternary systems of cotton burr compost, Peerless Fe(0), and a sediment low in organic carbon. Cotton burr compost acted as both organic carbon source and supporting material for the growth of indigenous denitrifiers. Batch tests showed that cotton burr compost alone removed added nitrate at a greater rate than did Peerless Fe(0) alone on an equal mass basis with a pseudo-first-order rate constant k=0.0830+/-0.0031 h(-1) for cotton burr compost and a k=0.00223+/-0.00022 h(-1) for Peerless Fe(0); cotton burr compost also removed added nitrate at a faster rate than did cotton burr compost mixed with Peerless Fe(0) and/or the sediment. Furthermore, there was no substantial accumulation of ammonium ions in the cotton burr compost system, in contrast to the systems containing Peerless Fe(0) in which ammonium ions persisted as major products of nitrate reduction. It is concluded that cotton burr compost alone may be used as an excellent denitrification medium in a PRB for groundwater nitrate removal. Further study is needed to evaluate performance of its field applications.

  3. Cloning and expression of antibacterial goat lactoferricin from Escherichia coli AD494(DE3)pLysS expression system.

    PubMed

    Chen, Gen-Hung; Yin, Li-Jung; Chiang, I-Hua; Jiang, Shann-Tzong

    2008-12-01

    Goat lactoferricin (GLfcin), an antibacterial peptide, is released from the N terminus of goat lactoferrin by pepsin digestion. Two GLfcin-related cDNAs, GLfcin L and GLfcin S, encoding Ala20-Ser60 and Ser36-Ser60 of goat lactoferrin, respectively, were cloned into the pET-23a(+) expression vector upstream from (His)6-Tag gene and transformed into Escherichia coli AD494(DE3)pLysS expression host. After being induced by isopropyl-beta-D-thiogalactopyranoside (IPTG), two (His)6-Tag fused recombinant lactoferricins, GLfcin L-His*Tag and GLfcin S-His*Tag, were expressed in soluble form within the E. coli cytoplasm. The GLfcin L-His*Tag and GLfcin S-His*Tag were purified using HisTrap affinity chromatography. According to an antibacterial activity assay using the agar diffusion method, GLfcin L-His*Tag had antibacterial activity against E. coli BCRC 11549, Staphylococcus aureus BCRC 25923, and Propionibacterium acnes BCRC 10723, while GLfcin S-His*Tag was able to inhibit the growth of E. coli BCRC 11549 and P. acnes BCRC 10723. These two recombinant lactoferricins behaved as thermostable peptides, which could retain their activity for up to 30 min of exposure at 100 degrees C.

  4. Cloning and expression of antibacterial goat lactoferricin from Escherichia coli AD494(DE3)pLysS expression system.

    PubMed

    Chen, Gen-Hung; Yin, Li-Jung; Chiang, I-Hua; Jiang, Shann-Tzong

    2008-12-01

    Goat lactoferricin (GLfcin), an antibacterial peptide, is released from the N terminus of goat lactoferrin by pepsin digestion. Two GLfcin-related cDNAs, GLfcin L and GLfcin S, encoding Ala20-Ser60 and Ser36-Ser60 of goat lactoferrin, respectively, were cloned into the pET-23a(+) expression vector upstream from (His)6-Tag gene and transformed into Escherichia coli AD494(DE3)pLysS expression host. After being induced by isopropyl-beta-D-thiogalactopyranoside (IPTG), two (His)6-Tag fused recombinant lactoferricins, GLfcin L-His*Tag and GLfcin S-His*Tag, were expressed in soluble form within the E. coli cytoplasm. The GLfcin L-His*Tag and GLfcin S-His*Tag were purified using HisTrap affinity chromatography. According to an antibacterial activity assay using the agar diffusion method, GLfcin L-His*Tag had antibacterial activity against E. coli BCRC 11549, Staphylococcus aureus BCRC 25923, and Propionibacterium acnes BCRC 10723, while GLfcin S-His*Tag was able to inhibit the growth of E. coli BCRC 11549 and P. acnes BCRC 10723. These two recombinant lactoferricins behaved as thermostable peptides, which could retain their activity for up to 30 min of exposure at 100 degrees C. PMID:19244908

  5. Introducing ADS 2.0

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.

    2014-01-01

    In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.

  6. The Added Economic and Environmental Value of Solar Thermal Systems in Microgrids with CombinedHeat and Power

    SciTech Connect

    Marnay, Chris; Stadler, Michael; Cardoso, Goncalo; Megel, Olivier; Lai, Judy; Siddiqui, Afzal

    2009-08-15

    The addition of solar thermal and heat storage systems can improve the economic, as well as environmental attraction of micro-generation systems, e.g. fuel cells with or without combined heat and power (CHP) and contribute to enhanced CO2 reduction. However, the interactions between solar thermal collection and storage systems and CHP systems can be complex, depending on the tariff structure, load profile, etc. In order to examine the impact of solar thermal and heat storage on CO2 emissions and annual energy costs, a microgrid's distributed energy resources (DER) adoption problem is formulated as a mixed-integer linear program. The objective is minimization of annual energy costs. This paper focuses on analysis of the optimal interaction of solar thermal systems, which can be used for domestic hot water, space heating and/or cooling, and micro-CHP systems in the California service territory of San Diego Gas and Electric (SDG&E). Contrary to typical expectations, our results indicate that despite the high solar radiation in southern California, fossil based CHP units are dominant, even with forecast 2020 technology and costs. A CO2 pricing scheme would be needed to incent installation of combined solar thermal absorption chiller systems, and no heat storage systems are adopted. This research also shows that photovoltaic (PV) arrays are favored by CO2 pricing more than solar thermal adoption.

  7. A comparative, randomized, controlled study on clinical efficacy and dental staining reduction of a mouthwash containing Chlorhexidine 0.20% and Anti Discoloration System (ADS)

    PubMed Central

    Marrelli, Massimo; Amantea, Massimiliano; Tatullo, Marco

    2015-01-01

    Summary Introduction A good control of bacterial plaque is an essential factor for the success of periodontal therapy, therefore it is the main objective that the clinician together with the patient must get to have a healthy periodontium. The plaque control with mouthwashes is the most important home therapy as it helps to reduce the formation of plaque between the mechanical removal with a toothbrush. Aim Authors analyzed the clinical data from a trial carried out with 3 different mouthwashes containing 0.2% Chlorhexidine (CHX). In addition, the ADS (Anti Discoloration System - Curaden Healthcare) was tested in comparison with the other mouthwashes without this system. Materials and methods We tested antiplaque activity showed by 3 of the most commercialized mouthwashes, moreover, we tested the ability in reducing the dental staining related to the oral assumption of Chlorhexidine. Discussion and conclusion Our results demonstrated the clinical efficacy of the 3 mouthwashes with CHX. Particularly performing was the anti discoloration system (Curaden Healthcare), with a clinical detection of dental stainings significantly less than the others tested. This study demonstrated the clinical efficacy of ADS system in the reduction of tooth staining, without a loss of antiplaque activity with respect to the competing mouthwashes containing CHX. PMID:26330902

  8. Total Body Water, Electrolyte, and Thermoregulatory Responses to Ad Libitum Water Replacement Using Two Different Water Delivery Systems During a 19-km Route March.

    PubMed

    Nolte, Heinrich W; Nolte, Kim; van der Meulen, Julia

    2015-11-01

    Hands-free hydration systems are often advocated for improved hydration and performance in military populations. The aim was to assess whether such systems indeed result in improved hydration in exercising soldiers. Subjects were required to complete a route march while consuming water ad libitum from either a hydration bladder (BG) or traditional canteen (CG). Water intakes of 538 ml·h⁻¹ (BG) and 533 ml·h⁻¹ (CG) resulted in no differences for changes in body mass, serum [Na], plasma osmolality, total body water, or time required to complete the march. There were no differences between peak exercise core temperature of the BG (38.9° C) and CG (38.7° C) groups. There were no differences between the groups for fluid balance, thermoregulation, or performance. This is a not a surprising finding because the amount of fluid consumed ad libitum is determined by changes in serum osmolality and not the fluid delivery system as often proposed. PMID:26506205

  9. Adding Innovation Diffusion Theory to the Technology Acceptance Model: Supporting Employees' Intentions to Use E-Learning Systems

    ERIC Educational Resources Information Center

    Lee, Yi-Hsuan; Hsieh, Yi-Chuan; Hsu, Chia-Ning

    2011-01-01

    This study intends to investigate factors affecting business employees' behavioral intentions to use the e-learning system. Combining the innovation diffusion theory (IDT) with the technology acceptance model (TAM), the present study proposes an extended technology acceptance model. The proposed model was tested with data collected from 552…

  10. The Tanzania Connect Project: a cluster-randomized trial of the child survival impact of adding paid community health workers to an existing facility-focused health system

    PubMed Central

    2013-01-01

    Background Tanzania has been a pioneer in establishing community-level services, yet challenges remain in sustaining these systems and ensuring adequate human resource strategies. In particular, the added value of a cadre of professional community health workers is under debate. While Tanzania has the highest density of primary health care facilities in Africa, equitable access and quality of care remain a challenge. Utilization for many services proven to reduce child and maternal mortality is unacceptably low. Tanzanian policy initiatives have sought to address these problems by proposing expansion of community-based providers, but the Ministry of Health and Social Welfare (MoHSW ) lacks evidence that this merits national implementation. The Tanzania Connect Project is a randomized cluster trial located in three rural districts with a population of roughly 360,000 ( Kilombero, Rufiji, and Ulanga). Description of intervention Connect aims to test whether introducing a community health worker into a general program of health systems strengthening and referral improvement will reduce child mortality, improve access to services, expand utilization, and alter reproductive, maternal, newborn and child health seeking behavior; thereby accelerating progress towards Millennium Development Goals 4 and 5. Connect has introduced a new cadre — Community Health Agents (CHA) — who were recruited from and work in their communities. To support the CHA, Connect developed supervisory systems, launched information and monitoring operations, and implemented logistics support for integration with existing district and village operations. In addition, Connect’s district-wide emergency referral strengthening intervention includes clinical and operational improvements. Evaluation design Designed as a community-based cluster-randomized trial, CHA were randomly assigned to 50 of the 101 villages within the Health and Demographic Surveillance System (HDSS) in the three study districts

  11. Agricultural Education: Value Adding.

    ERIC Educational Resources Information Center

    Riesenberg, Lou E.; And Others

    1989-01-01

    This issue develops the theme of "Agricultural Education--Value Adding." The concept value adding has been a staple in the world of agricultural business for describing adding value to a commodity that would profit the producer and the local community. Agricultural education should add value to individuals and society to justify agricultural…

  12. Adding a strategic edge to human factors/ergonomics: principles for the management of uncertainty as cornerstones for system design.

    PubMed

    Grote, Gudela

    2014-01-01

    It is frequently lamented that human factors and ergonomics knowledge does not receive the attention and consideration that it deserves. In this paper I argue that in order to change this situation human factors/ergonomics based system design needs to be positioned as a strategic task within a conceptual framework that incorporates both business and design concerns. The management of uncertainty is presented as a viable candidate for such a framework. A case is described where human factors/ergonomics experts in a railway company have used the management of uncertainty perspective to address strategic concerns at firm level. Furthermore, system design is discussed in view of the relationship between organization and technology more broadly. System designers need to be supported in better understanding this relationship in order to cope with the uncertainties this relationship brings to the design process itself. Finally, the emphasis on uncertainty embedded in the recent surge of introducing risk management across all business sectors is suggested as another opportunity for bringing human factors and ergonomics expertise to the fore.

  13. Partly exhausted soda lime or soda lime with water added, inhibits the increase in compound A concentration in the circle system during low-flow sevoflurane anaesthesia.

    PubMed

    Moriwaki, G; Bito, H; Ikeda, K

    1997-12-01

    We performed low-flow sevoflurane anaesthesia at a flow rate of 1 litre min-1 in three groups (n = 8 each) using 600 g of fresh soda lime (control group), 600 g of soda lime with 60 ml of water added (water group) or 600 g of soda lime saturated with carbon dioxide, that is partly exhausted soda lime (carbon dioxide group). Degradation products in the system were measured hourly. Inspired and end-tidal carbon dioxide and sevoflurane concentrations, carbon dioxide and temperature of the soda lime were monitored. CF2 = C(CF3)-O-CH2F (compound A) was the only sevoflurane degradation product detected. The mean maximum concentration of compound A was significantly higher in the control group (mean 16.0 (SD 5.0) ppm) than in the water (1.4 (1.0) ppm) or carbon dioxide (4.0 (1.8) ppm) group, and the maximum temperature of the soda lime was significantly lower in the carbon dioxide group (30.7 (3.5) degrees C) than in the control (43.4 (1.8) degrees C) or water (40.8 (1.8) degrees C) group (P < 0.05). The use of partly exhausted soda lime or soda lime with water added reduced compound A concentrations in the system during low-flow sevoflurane anaesthesia.

  14. Adding Industry and Occupation Questions to the Behavioral Risk Factor Surveillance System: New Opportunities in Public Health Surveillance

    PubMed Central

    Tolliver, Rickey; Bui, Alison Grace; Warner, Amy; Van Dyke, Mike

    2015-01-01

    Objectives Industry and occupation variables are overlooked in many public health surveillance efforts, yet they are useful for describing the burden and distribution of various public health diseases, behaviors, and conditions. This study is the first ever analysis of the Colorado Behavioral Risk Factor Surveillance System (BRFSS) to describe chronic conditions and risk behaviors by occupation. It is intended to provide a new perspective on this existing data source and demonstrate the value of occupation as a core demographic variable for public health research, policy, and practice. Methods Two standardized employment questions were included in the 2012 Colorado BRFSS survey and administered to eligible survey respondents who were employed, self-employed, or out of work for less than one year. Occupation data were coded using the National Institute for Occupational Safety and Health (NIOSH) Industry and Occupation Computerized Coding System. We analyzed health behaviors and conditions by major occupation groups. We calculated prevalence estimates and 95% confidence intervals (CIs). Results The prevalence of chronic conditions, health statuses, and risk behaviors (e.g., smoking and seatbelt use) varied significantly by occupation. For example, compared with all workers (93.6%, 95% CI 92.7, 94.5), significantly fewer workers in farming, forestry, fishing and construction, extraction jobs (87.0%, 95% CI 82.0, 92.0) reported always or nearly always wearing a seatbelt while driving. Additionally, significantly more office and administrative support workers (27.5%, 95% CI 22.5, 32.4) compared with all workers (20.6%, 95% CI 19.3, 22.0) were obese. Further observation and research is needed to understand the effects of occupation on health outcomes and behaviors. Conclusion There are no other Colorado state-level datasets that link health behaviors and chronic conditions with occupation. This study shows that the prevalence of chronic conditions and risk behaviors

  15. Adding flavor to AdS4/CFT3

    NASA Astrophysics Data System (ADS)

    Ammon, Martin; Erdmenger, Johanna; Meyer, René; O'Bannon, Andy; Wrase, Timm

    2009-11-01

    Aharony, Bergman, Jafferis, and Maldacena have proposed that the low-energy description of multiple M2-branes at a Bbb C4/Bbb Zk singularity is a (2+1)-dimensional Script N = 6 supersymmetric U(Nc) × U(Nc) Chern-Simons matter theory, the ABJM theory. In the large-Nc limit, its holographic dual is supergravity in AdS4 × S7/Bbb Zk. We study various ways to add fields that transform in the fundamental representation of the gauge groups, i.e. flavor fields, to the ABJM theory. We work in a probe limit and perform analyses in both the supergravity and field theory descriptions. In the supergravity description we find a large class of supersymmetric embeddings of probe flavor branes. In the field theory description, we present a general method to determine the couplings of the flavor fields to the fields of the ABJM theory. We then study four examples in detail: codimension-zero Script N = 3 supersymmetric flavor, described in supergravity by Kaluza-Klein monopoles or D6-branes; codimension-one Script N = (0,6) supersymmetric chiral flavor, described by D8-branes; codimension-one Script N = (3,3) supersymmetric non-chiral flavor, described by M5/D4-branes; codimension-two Script N = 4 supersymmetric flavor, described by M2/D2-branes. Finally we discuss special physical equivalences between brane embeddings in M-theory, and their interpretation in the field theory description.

  16. Twistor methods for AdS5

    NASA Astrophysics Data System (ADS)

    Adamo, Tim; Skinner, David; Williams, Jack

    2016-08-01

    We consider the application of twistor theory to five-dimensional anti-de Sitter space. The twistor space of AdS5 is the same as the ambitwistor space of the four-dimensional conformal boundary; the geometry of this correspondence is reviewed for both the bulk and boundary. A Penrose transform allows us to describe free bulk fields, with or without mass, in terms of data on twistor space. Explicit representatives for the bulk-to-boundary propagators of scalars and spinors are constructed, along with twistor action functionals for the free theories. Evaluating these twistor actions on bulk-to-boundary propagators is shown to produce the correct two-point functions.

  17. AdS3: the NHEK generation

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Heurtier, Lucien; Puhm, Andrea

    2016-05-01

    It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.

  18. Shadows, currents, and AdS fields

    SciTech Connect

    Metsaev, R. R.

    2008-11-15

    Conformal totally symmetric arbitrary spin currents and shadow fields in flat space-time of dimension greater than or equal to four are studied. A gauge invariant formulation for such currents and shadow fields is developed. Gauge symmetries are realized by involving the Stueckelberg fields. A realization of global conformal boost symmetries is obtained. Gauge invariant differential constraints for currents and shadow fields are obtained. AdS/CFT correspondence for currents and shadow fields and the respective normalizable and non-normalizable solutions of massless totally symmetric arbitrary spin AdS fields are studied. The bulk fields are considered in a modified de Donder gauge that leads to decoupled equations of motion. We demonstrate that leftover on shell gauge symmetries of bulk fields correspond to gauge symmetries of boundary currents and shadow fields, while the modified de Donder gauge conditions for bulk fields correspond to differential constraints for boundary conformal currents and shadow fields. Breaking conformal symmetries, we find interrelations between the gauge invariant formulation of the currents and shadow fields, and the gauge invariant formulation of massive fields.

  19. Influence of fresh date palm co-products on the ripening of a paprika added dry-cured sausage model system.

    PubMed

    Martín-Sánchez, Ana María; Ciro-Gómez, Gelmy; Vilella-Esplá, José; Ben-Abda, Jamel; Pérez-Álvarez, José Ángel; Sayas-Barberá, Estrella

    2014-06-01

    Date palm co-products are a source of bioactive compounds that could be used as a new ingredient for the meat industry. An intermediate food product (IFP) from date palm co-products (5%) was incorporated into a paprika added dry-cured sausage (PADS) model system and was analysed for physicochemical parameters, lipid oxidation and sensory attributes during ripening. Addition of 5% IFP yielded a product with physicochemical properties similar to the traditional one. Instrumental colour differences were found, but were not detected visually by panellists, who also evaluated positively the sensory properties of the PADS with IFP. Therefore, the IFP from date palm co-products could be used as a natural ingredient in the formulation of PADS.

  20. Perfect fluidity of a dissipative system: Analytical solution for the Boltzmann equation in AdS2 Ⓧ S2

    SciTech Connect

    Noronha, Jorge; Denicol, Gabriel S.

    2015-12-30

    In this paper we obtain an analytical solution of the relativistic Boltzmann equation under the relaxation time approximation that describes the out-of-equilibrium dynamics of a radially expanding massless gas. This solution is found by mapping this expanding system in flat spacetime to a static flow in the curved spacetime AdS2 Ⓧ S2. We further derive explicit analytic expressions for the momentum dependence of the single-particle distribution function as well as for the spatial dependence of its moments. We find that this dissipative system has the ability to flow as a perfect fluid even though its entropy density does not match the equilibrium form. The nonequilibrium contribution to the entropy density is shown to be due to higher-order scalar moments (which possess no hydrodynamical interpretation) of the Boltzmann equation that can remain out of equilibrium but do not couple to the energy-momentum tensor of the system. Furthermore, in this system the slowly moving hydrodynamic degrees of freedom can exhibit true perfect fluidity while being totally decoupled from the fast moving, nonhydrodynamical microscopic degrees of freedom that lead to entropy production.

  1. Capacitive beam position monitors for the low-β beam of the Chinese ADS proton linac

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Wu, Jun-Xia; Zhu, Guang-Yu; Jia, Huan; Xue, Zong-Heng; Zheng, Hai; Xie, Hong-Ming; Kang, Xin-Cai; He, Yuan; Li, Lin; Denard, Jean Claude

    2016-02-01

    Beam Position Monitors (BPMs) for the low-β beam of the Chinese Accelerator Driven Subcritical system (CADS) Proton linac are of the capacitive pick-up type. They provide higher output signals than that of the inductive type. This paper will describe the design and tests of the capacitive BPM system for the low-β proton linac, including the pick-ups, the test bench and the read-out electronics. The tests done with an actual proton beam show a good agreement between the measurements and the simulations in the time domain. Supported by National Natural Science Foundation of China (11405240) and “Western Light” Talents Training Program of Chinese Academy of Sciences

  2. New Features in ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Di Milia, G.; Luker, J.; Murray, S. S.

    2013-01-01

    The NASA Astrophysics Data System (ADS) has been working hard on updating its services and interfaces to better support our community's research needs. ADS Labs is a new interface built on the old tried-and-true ADS Abstract Databases, so all of ADS's content is available through it. In this presentation we highlight the new features that have been developed in ADS Labs over the last year: new recommendations, metrics, a citation tool and enhanced fulltext search. ADS Labs has long been providing article-level recommendations based on keyword similarity, co-readership and co-citation analysis of its corpus. We have now introduced personal recommendations, which provide a list of articles to be considered based on a individual user's readership history. A new metrics interface provides a summary of the basic impact indicators for a list of records. These include the total and normalized number of papers, citations, reads, and downloads. Also included are some of the popular indices such as the h, g and i10 index. The citation helper tool allows one to submit a set of records and obtain a list of top 10 papers which cite and/or are cited by papers in the original list (but which are not in it). The process closely resembles the network approach of establishing "friends of friends" via an analysis of the citation network. The full-text search service now covers more than 2.5 million documents, including all the major astronomy journals, as well as physics journals published by Springer, Elsevier, the American Physical Society, the American Geophysical Union, and all of the arXiv eprints. The full-text search interface interface allows users and librarians to dig deep and find words or phrases in the body of the indexed articles. ADS Labs is available at http://adslabs.org

  3. Ocean-Based Alkalinity Enhancement: Mitigation Potential, Side Effects and the Fate of Added Alkalinity Assessed in an Earth System Model

    NASA Astrophysics Data System (ADS)

    Gonzalez, M. F.; Ilyina, T.

    2014-12-01

    Artificial ocean alkalinization (AOA) has been proposed as a mean to mitigate climate change and ocean acidification. Whilst the mitigation potential of this geo-engineering technology may sound promising, it poses environmental risks. Within the Priority Program "Climate Engineering" of the German Science Foundation (DFG), we investigate the mitigation potential of AOA to reduce atmospheric CO2 and counteract the consequences of ocean acidification. We are particularly interested in the residence time of the added alkalinity at the ocean surface because it must stay in the upper ocean in order to increase the oceanic CO2 uptake. The mitigation potential, risks and the unintended consequences of this geo-engineering method are also exhaustively studied. These questions are tackled through the analysis of different alkalinity enhancement scenarios in the state-of-the-art Earth system model of the Max Planck Institute for Meteorology (MPI-ESM) in a configuration based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Model scenarios are designed so that AOA is performed to keep the atmospheric CO2 concentrations similar to values of the stabilization scenario RCP4.5, while fossil fuel CO2 emissions follow the pathway of the high-CO2 scenario RCP8.5. Alkalinity is added globally into the upper 12 meters of the ocean in different seasons and years. We found that on the time scale of relevance (i.e. from years to decades), season and location are key aspects to take into account in the implementation of AOA. This is because of inhomogeneous vertical mixing of added alkalinity due to the mixed layer depth which is established by the season. We also show that the rate of addition greatly determines impact and outcome of this geo-engineering method. Changes driven by the implementation of this method in the ocean biogeochemistry are also discussed. For instance, the associated changes in the carbon cycle, marine oxygen levels, saturation state of

  4. The Added-Value of Using Participatory Approaches to Assess the Acceptability of Surveillance Systems: The Case of Bovine Tuberculosis in Belgium

    PubMed Central

    Calba, Clémentine; Goutard, Flavie Luce; Vanholme, Luc; Antoine-Moussiaux, Nicolas; Hendrikx, Pascal; Saegerman, Claude

    2016-01-01

    Context and Objective Bovine tuberculosis (bTB) surveillance in Belgium is essential to maintain the officially free status and to preserve animal and public health. An evaluation of the system is thus needed to ascertain the surveillance provides a precise description of the current situation in the country. The evaluation should assess stakeholders’ perceptions and expectations about the system due to the fact that the acceptability has an influence on the levels of sensitivity and timeliness of the surveillance system. The objective of the study was to assess the acceptability of the bTB surveillance in Belgium, using participatory tools and the OASIS flash tool (‘analysis tool for surveillance systems’). Methods For the participatory process, focus group discussions and individual interviews were implemented with representatives involved with the system, both from cattle and wildlife part of the surveillance. Three main tools were used: (i) relational diagrams associated with smileys, (ii) flow diagrams associated with proportional piling, and (iii) impact diagrams associated with proportional piling. A total of six criteria were assessed, among which five were scored on a scale from -1 to +1. For the OASIS flash tool, one full day meeting with representatives from stakeholders involved with the surveillance was organised. A total of 19 criteria linked to acceptability were scored on a scale from 0 to 3. Results and Conclusion Both methods highlighted a medium acceptability of the bTB surveillance. The main elements having a negative influence were the consequences of official notification of a bTB suspect case in a farm, the low remuneration paid to private veterinarians for execution of intradermal tuberculin tests and the practical difficulties about the containment of the animals. Based on the two evaluation processes, relevant recommendations to improve the surveillance were made. Based on the comparison between the two evaluation processes, the

  5. Effect of added water, sodium erythorbate and storage time on the functional properties of prerigor beef preblends in a model system.

    PubMed

    Abu-Bakar, A; Reagan, J O; Carpenter, J A; Miller, M F

    1989-01-01

    Singular and combined effects of added water, sodium erythorbate and storage time on salt soluble protein extractability, bacteriological and chemical characteristics of preblended hot-boned beef were evaluated. Waterholding and gel forming capacities of preblended hot-boned beef containing either 0, 10 or 20% added water were determined. Significant interactions between added water level and storage time on microbial counts and between sodium erythorbate level and storage time on thiobarbituric acid values and residual nitrite levels were noted. The presence of sodium erythorbate resulted in a more (P < 0·05) rapid rate of nitrite disappearance, but it did not affect (P > 0·05) microbial counts. Salt-soluble protein extractability was not affected (P > 0·05) by added water, but more protein could be extracted with increasing storage time. A trend existed to suggest that the presence of added water in the meat preblends slightly improved the gel formation and waterholding capacities.

  6. ADS's Dexter Data Extraction Applet

    NASA Astrophysics Data System (ADS)

    Demleitner, M.; Accomazzi, A.; Eichhorn, G.; Grant, C. S.; Kurtz, M. J.; Murray, S. S.

    The NASA Astrophysics Data System (ADS) now holds 1.3 million scanned pages, containing numerous plots and figures for which the original data sets are lost or inaccessible. The availability of scans of the figures can significantly ease the regeneration of the data sets. For this purpose, the ADS has developed Dexter, a Java applet that supports the user in this process. Dexter's basic functionality is to let the user manually digitize a plot by marking points and defining the coordinate transformation from the logical to the physical coordinate system. Advanced features include automatic identification of axes, tracing lines and finding points matching a template. This contribution both describes the operation of Dexter from a user's point of view and discusses some of the architectural issues we faced during implementation.

  7. Cryogenic system for the MYRRHA superconducting linear accelerator

    SciTech Connect

    Chevalier, Nicolas R.; Junquera, Tomas; Thermeau, Jean-Pierre; Romão, Luis Medeiros; Vandeplassche, Dirk

    2014-01-29

    SCK⋅CEN, the Belgian Nuclear Research Centre, is designing MYRRHA, a flexible fast spectrum research reactor (80 MW{sub th}), conceived as an accelerator driven system (ADS), able to operate in sub-critical and critical modes. It contains a continuous-wave (CW) superconducting (SC) proton accelerator of 600 MeV, a spallation target and a multiplying core with MOX fuel, cooled by liquid lead-bismuth (Pb-Bi). From 17 MeV onward, the SC accelerator will consist of 48 β=0.36 spoke-loaded cavities (352 MHz), 34 β=0.47 elliptical cavities (704 MHz) and 60 β=0.65 elliptical cavities (704 MHz). We present an analysis of the thermal loads and of the optimal operating temperature of the cryogenic system. In particular, the low operating frequency of spoke cavities makes their operation in CW mode possible both at 4.2 K or at 2 K. Our analysis outlines the main factors that determine at what temperature the spoke cavities should be operated. We then present different cryogenic fluid distribution schemes, important characteristics (storage, transfer line, etc.) and the main challenges offered by MYRRHA in terms of cryogenics.

  8. Cryogenic system for the MYRRHA superconducting linear accelerator

    NASA Astrophysics Data System (ADS)

    Chevalier, Nicolas R.; Junquera, Tomas; Thermeau, Jean-Pierre; Romão, Luis Medeiros; Vandeplassche, Dirk

    2014-01-01

    SCKṡCEN, the Belgian Nuclear Research Centre, is designing MYRRHA, a flexible fast spectrum research reactor (80 MWth), conceived as an accelerator driven system (ADS), able to operate in sub-critical and critical modes. It contains a continuous-wave (CW) superconducting (SC) proton accelerator of 600 MeV, a spallation target and a multiplying core with MOX fuel, cooled by liquid lead-bismuth (Pb-Bi). From 17 MeV onward, the SC accelerator will consist of 48 β=0.36 spoke-loaded cavities (352 MHz), 34 β=0.47 elliptical cavities (704 MHz) and 60 β=0.65 elliptical cavities (704 MHz). We present an analysis of the thermal loads and of the optimal operating temperature of the cryogenic system. In particular, the low operating frequency of spoke cavities makes their operation in CW mode possible both at 4.2 K or at 2 K. Our analysis outlines the main factors that determine at what temperature the spoke cavities should be operated. We then present different cryogenic fluid distribution schemes, important characteristics (storage, transfer line, etc.) and the main challenges offered by MYRRHA in terms of cryogenics.

  9. Monitoring of slope-instabilities and deformations with Micro-Electro-Mechanical-Systems (MEMS) in wireless ad-hoc Sensor Networks

    NASA Astrophysics Data System (ADS)

    Arnhardt, C.; Fernández-Steeger, T. M.; Azzam, R.

    2009-04-01

    In most mountainous regions, landslides represent a major threat to human life, properties and infrastructures. Nowadays existing landslide monitoring systems are often characterized by high efforts in terms of purchase, installation, maintenance, manpower and material. In addition (or because of this) only small areas or selective points of the endangered zone can be observed by the system. Therefore the improvement of existing and the development of new monitoring and warning systems are of high relevance. The joint project "Sensor based Landslide Early Warning Systems" (SLEWS) deals with the development of a prototypic Alarm- and Early Warning system (EWS) for different types of landslides using low-cost micro-sensors (MEMS) integrated in a wireless sensor network (WSN). Modern so called Ad-Hoc, Multi-Hop wireless sensor networks (WSN) are characterized by a self organizing and self-healing capacity of the system (autonomous systems). The network consists of numerous individual and own energy-supply operating sensor nodes, that can send data packages from their measuring devices (here: MEMS) over other nodes (Multi-Hop) to a collection point (gateway). The gateway provides the interface to central processing and data retrieval units (PC, Laptop or server) outside the network. In order to detect and monitor the different landslide processes (like fall, topple, spreading or sliding) 3D MEMS capacitive sensors made from single silicon crystals and glass were chosen to measure acceleration, tilting and altitude changes. Based on the so called MEMS (Micro-Electro-Mechanical Systems) technology, the sensors combine very small mechanical and electronic units, sensing elements and transducers on a small microchip. The mass production of such type of sensors allows low cost applications in different areas (like automobile industries, medicine, and automation technology). Apart from the small and so space saving size and the low costs another advantage is the energy

  10. What Value "Value Added"?

    ERIC Educational Resources Information Center

    Richards, Andrew

    2015-01-01

    Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…

  11. Introducing ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Henneken, E.; Grant, C. S.; Kurtz, M. J.; Di Milia, G.; Luker, J.; Thompson, D. M.; Bohlen, E.; Murray, S. S.

    2011-05-01

    ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties ("facets"), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org

  12. Subsurface geology, ancient hydrothermal systems and crater excavation processes beneath Lake Rotomahana: Evidence from lithic clasts of the 1886 AD Rotomahana Pyroclastics

    NASA Astrophysics Data System (ADS)

    Pittari, A.; Briggs, R. M.; Bowyer, D. A.

    2016-03-01

    The craters associated with the 1886 AD phreatomagmatic Rotomahana eruption, Okataina Volcanic Centre, New Zealand, and the near-vent geology are now hidden beneath Lake Rotomahana and its post-eruptive sediment fill. Lithic clasts from the near-vent lithic lapilli ash deposits of the Rotomahana Pyroclastics are used in this study to trace geological and geothermal conditions before the eruption, as well as vent excavation dynamics. Near-vent deposit characteristics were described in the field, representative lithic clasts were documented petrographically, and unaltered clasts were analysed for major and trace element compositions. The majority of the lithic clasts were rhyolites with subordinate ignimbrites and hydrothermally altered clasts, and trace siltstone and silicified clasts. The rhyolites were classified into four petrographic groups according to phenocryst content and assemblage and were more diverse with respect to geochemical compositions. Most of the rhyolite lithics in the Rotomahana Pyroclastics did not match the rhyolite domes exposed subaerially around the lake, but did have affinities with the pre-Matahina caldera Wairua Rhyolite, and potentially other older non-exposed domes. Ignimbrites most likely correlated either to the Matahina ignimbrite or older non-exposed units. Hydrothermally altered rhyolite and ignimbrite lithic clasts are common and suggest that there has been a long-lived hydrothermal system in this sector, possibly dating back to early activity of the Okataina Volcanic Centre. The diversity in lithic types indicate a spatial variation in country rock lithology and strength, which probably contributed to the vent position and morphology along the Rotomahana fissure.

  13. Parallel implementation of inverse adding-doubling and Monte Carlo multi-layered programs for high performance computing systems with shared and distributed memory

    NASA Astrophysics Data System (ADS)

    Chugunov, Svyatoslav; Li, Changying

    2015-09-01

    Parallel implementation of two numerical tools popular in optical studies of biological materials-Inverse Adding-Doubling (IAD) program and Monte Carlo Multi-Layered (MCML) program-was developed and tested in this study. The implementation was based on Message Passing Interface (MPI) and standard C-language. Parallel versions of IAD and MCML programs were compared to their sequential counterparts in validation and performance tests. Additionally, the portability of the programs was tested using a local high performance computing (HPC) cluster, Penguin-On-Demand HPC cluster, and Amazon EC2 cluster. Parallel IAD was tested with up to 150 parallel cores using 1223 input datasets. It demonstrated linear scalability and the speedup was proportional to the number of parallel cores (up to 150x). Parallel MCML was tested with up to 1001 parallel cores using problem sizes of 104-109 photon packets. It demonstrated classical performance curves featuring communication overhead and performance saturation point. Optimal performance curve was derived for parallel MCML as a function of problem size. Typical speedup achieved for parallel MCML (up to 326x) demonstrated linear increase with problem size. Precision of MCML results was estimated in a series of tests - problem size of 106 photon packets was found optimal for calculations of total optical response and 108 photon packets for spatially-resolved results. The presented parallel versions of MCML and IAD programs are portable on multiple computing platforms. The parallel programs could significantly speed up the simulation for scientists and be utilized to their full potential in computing systems that are readily available without additional costs.

  14. The forecaster's added value

    NASA Astrophysics Data System (ADS)

    Turco, M.; Milelli, M.

    2009-09-01

    skill scores of two competitive forecast. It is important to underline that the conclusions refer to the analysis of the Piemonte operational alert system, so they cannot be directly taken as universally true. But we think that some of the main lessons that can be derived from this study could be useful for the meteorological community. In details, the main conclusions are the following: - despite the overall improvement in global scale and the fact that the resolution of the limited area models has increased considerably over recent years, the QPF produced by the meteorological models involved in this study has not improved enough to allow its direct use, that is, the subjective HQPF continues to offer the best performance; - in the forecast process, the step where humans have the largest added value with respect to mathematical models, is the communication. In fact the human characterisation and communication of the forecast uncertainty to end users cannot be replaced by any computer code; - eventually, although there is no novelty in this study, we would like to show that the correct application of appropriated statistical techniques permits a better definition and quantification of the errors and, mostly important, allows a correct (unbiased) communication between forecasters and decision makers.

  15. Canonical energy and hairy AdS black holes

    NASA Astrophysics Data System (ADS)

    Hyun, Seungjoon; Park, Sang-A.; Yi, Sang-Heon

    2016-08-01

    We propose the modified version of the canonical energy which was introduced originally by Hollands and Wald. Our construction depends only on the Euler-Lagrange expression of the system and thus is independent of the ambiguity in the Lagrangian. After some comments on our construction, we briefly mention on the relevance of our construction to the boundary information metric in the context of the AdS/CFT correspondence. We also study the stability of three-dimensional hairy extremal black holes by using our construction.

  16. Monitoring of slope-instabilities and deformations with Micro-Electro-Mechanical-Systems (MEMS) in wireless ad-hoc Sensor Networks

    NASA Astrophysics Data System (ADS)

    Arnhardt, C.; Fernández-Steeger, T. M.; Azzam, R.

    2009-04-01

    In most mountainous regions, landslides represent a major threat to human life, properties and infrastructures. Nowadays existing landslide monitoring systems are often characterized by high efforts in terms of purchase, installation, maintenance, manpower and material. In addition (or because of this) only small areas or selective points of the endangered zone can be observed by the system. Therefore the improvement of existing and the development of new monitoring and warning systems are of high relevance. The joint project "Sensor based Landslide Early Warning Systems" (SLEWS) deals with the development of a prototypic Alarm- and Early Warning system (EWS) for different types of landslides using low-cost micro-sensors (MEMS) integrated in a wireless sensor network (WSN). Modern so called Ad-Hoc, Multi-Hop wireless sensor networks (WSN) are characterized by a self organizing and self-healing capacity of the system (autonomous systems). The network consists of numerous individual and own energy-supply operating sensor nodes, that can send data packages from their measuring devices (here: MEMS) over other nodes (Multi-Hop) to a collection point (gateway). The gateway provides the interface to central processing and data retrieval units (PC, Laptop or server) outside the network. In order to detect and monitor the different landslide processes (like fall, topple, spreading or sliding) 3D MEMS capacitive sensors made from single silicon crystals and glass were chosen to measure acceleration, tilting and altitude changes. Based on the so called MEMS (Micro-Electro-Mechanical Systems) technology, the sensors combine very small mechanical and electronic units, sensing elements and transducers on a small microchip. The mass production of such type of sensors allows low cost applications in different areas (like automobile industries, medicine, and automation technology). Apart from the small and so space saving size and the low costs another advantage is the energy

  17. Two Virasoro symmetries in stringy warped AdS3

    NASA Astrophysics Data System (ADS)

    Compère, Geoffrey; Guica, Monica; Rodriguez, Maria J.

    2014-12-01

    We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS3. Consequently, for each consistent choice of boundary conditions in AdS3, we can define a consistent phase space in warped AdS3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS3; two different types of Virasoro × Kač-Moody symmetries are also consistent alternatives.

  18. Scientific and Technological Information for Development. Proceedings of the Ad-hoc Panel of Experts on Information Systems for Science and Technology for Development (Rome, Italy, January 21-25, 1985).

    ERIC Educational Resources Information Center

    United Nations, New York, NY.

    The report of the ad-hoc panel and the 25 papers in these proceedings cover a wide spectrum of issues and perspectives relating to information systems, services, and networks at both the national and international levels. The first part of this six-part volume presents the panel's report, which reviews the history of the panel and its purpose and…

  19. Leading Change, Adding Value.

    PubMed

    Evans, Nick

    2016-09-12

    Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View. PMID:27615573

  20. A stochasticity threshold in holography and the instability of AdS

    NASA Astrophysics Data System (ADS)

    Basu, Pallab; Krishnan, Chethan; Saurabh, Ayush

    2015-07-01

    We give strong numerical evidence that a self-interacting probe scalar field in AdS, with only a few modes turned on initially, will undergo fast thermalization only if it is above a certain energetic threshold. Below the threshold the energy stays close to constant in a few modes for a very long time instead of cascading quickly. This indicates the existence of a Strong Stochasticity Threshold (SST) in holography. The idea of SST is familiar from certain statistical mechanical systems, and we suggest that it exists also in AdS gravity. This would naturally reconcile the generic nonlinear instability of AdS observed by Bizon and Rostworowski, with the Fermi-Pasta-Ulam-Tsingou-like quasiperiodicity noticed recently for some classes of initial conditions. We show that our simple setup captures many of the relevant features of the full gravity-scalar system.

  1. Nonlinear realization of local symmetries of AdS space

    SciTech Connect

    Clark, T.E.; Love, S.T.; Nitta, Muneto; Veldhuis, T. ter

    2005-10-15

    Coset methods are used to construct the action describing the dynamics associated with the spontaneous breaking of the local symmetries of AdS{sub d+1} space due to the embedding of an AdS{sub d} brane. The resulting action is an SO(2,d) invariant AdS form of the Einstein-Hilbert action, which in addition to the AdS{sub d} gravitational vielbein, also includes a massive vector field localized on the brane. Its long wavelength dynamics is the same as a massive Abelian vector field coupled to gravity in AdS{sub d} space.

  2. Bubbling geometries for AdS2× S2

    NASA Astrophysics Data System (ADS)

    Lunin, Oleg

    2015-10-01

    We construct BPS geometries describing normalizable excitations of AdS2×S2. All regular horizon-free solutions are parameterized by two harmonic functions in R 3 with sources along closed curves. This local structure is reminiscent of the "bubbling solutions" for the other AdS p ×S q cases, however, due to peculiar asymptotic properties of AdS2, one copy of R 3 does not cover the entire space, and we discuss the procedure for analytic continuation, which leads to a nontrivial topological structure of the new geometries. We also study supersymmetric brane probes on the new geometries, which represent the AdS2×S2 counterparts of the giant gravitons.

  3. Status of the LAHET{trademark} Code System

    SciTech Connect

    Waters, L.S.; Prael, R.E.

    1995-12-31

    The LAHET Code System (LCS) is extensively used for medium energy accelerator applications, including spallation target design and deep penetration shielding problems. Current applications include Accelerator Production of Tritium (APT), Accelerator Driven Transmutation Technologies (ADTT), LANSCE and WNR spallation target upgrades, as well as various medical projects. We will discuss recent upgrades to the MCNP and LAHET components of LCS, AND review the work in progress now funded under the APT program.

  4. [Value-Added--Adding Economic Value in the Food Industry].

    ERIC Educational Resources Information Center

    Welch, Mary A., Ed.

    1989-01-01

    This booklet focuses on the economic concept of "value added" to goods and services. A student activity worksheet illustrates how the steps involved in processing food are examples of the concept of value added. The booklet further links food processing to the idea of value added to the Gross National Product (GNP). Discussion questions, a student…

  5. The ADS All Sky Survey

    NASA Astrophysics Data System (ADS)

    Goodman, Alyssa

    We will create the first interactive sky map of astronomers' understanding of the Universe over time. We will accomplish this goal by turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource, into a data resource. GIS and GPS systems have made it commonplace to see and explore information about goings-on on Earth in the context of maps and timelines. Our proposal shows an example of a program that lets a user explore which countries have been mentioned in the New York Times, on what dates, and in what kinds of articles. By analogy, the goal of our project is to enable this kind of exploration-on the sky-for the full corpus of astrophysical literature available through ADS. Our group's expertise and collaborations uniquely position us to create this interactive sky map of the literature, which we call the "ADS All-Sky Survey." To create this survey, here are the principal steps we need to follow. First, by analogy to "geotagging," we will "astrotag," the ADS literature. Many "astrotags" effectively already exist, thanks to curation efforts at both CDS and NED. These efforts have created links to "source" positions on the sky associated with each of the millions of articles in the ADS. Our collaboration with ADS and CDS will let us automatically extract astrotags for all existing and future ADS holdings. The new ADS Labs, which our group helps to develop, includes the ability for researchers to filter article search results using a variety of "facets" (e.g. sources, keywords, authors, observatories, etc.). Using only extracted astrotags and facets, we can create functionality like what is described in the Times example above: we can offer a map of the density of positions' "mentions" on the sky, filterable by the properties of those mentions. Using this map, researchers will be able to interactively, visually, discover what regions have been studied for what reasons, at what times, and by whom. Second, where

  6. 78 FR 8145 - Sequence 24 Findings of the EISA 436(h) Ad-Hoc Review Group on Green Building Certification Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... certification system(s) most likely to encourage a comprehensive and environmentally- sound approach to the... to the Secretary of Energy on what green building certification system(s) the Federal government... certification systems and provide a formal recommendation to the Secretary of Energy on how green...

  7. Action growth for AdS black holes

    NASA Astrophysics Data System (ADS)

    Cai, Rong-Gen; Ruan, Shan-Ming; Wang, Shao-Jiang; Yang, Run-Qiu; Peng, Rong-Hui

    2016-09-01

    Recently a Complexity-Action (CA) duality conjecture has been proposed, which relates the quantum complexity of a holographic boundary state to the action of a Wheeler-DeWitt (WDW) patch in the anti-de Sitter (AdS) bulk. In this paper we further investigate the duality conjecture for stationary AdS black holes and derive some exact results for the growth rate of action within the Wheeler-DeWitt (WDW) patch at late time approximation, which is supposed to be dual to the growth rate of quantum complexity of holographic state. Based on the results from the general D-dimensional Reissner-Nordström (RN)-AdS black hole, rotating/charged Bañados-Teitelboim-Zanelli (BTZ) black hole, Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a universal formula for the action growth expressed in terms of some thermodynamical quantities associated with the outer and inner horizons of the AdS black holes. And we leave the conjecture unchanged that the stationary AdS black hole in Einstein gravity is the fastest computer in nature.

  8. The fast-spectrum transmutation experimental facility FASTEF: Main design achievements (Part 1: Core and primary system) within the FP7-CDT collaborative project of the European Commission

    SciTech Connect

    De Bruyn, D.; Fernandez, R.; Mansani, L.; Woaye-Hune, A.; Sarotto, M.; Bubelis, E.

    2012-07-01

    MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) is the flexible experimental accelerator-driven system (ADS) in development at SCK CEN in replacement of its material testing reactor BR2. SCK CEN in association with 17 European partners from industry, research centres and academia, responded to the FP7 (Seventh Framework Programme) call from the European Commission to establish a Central Design Team (CDT) for the design of a Fast Spectrum Transmutation Experimental Facility (FASTEF) able to demonstrate efficient transmutation and associated technology through a system working in subcritical and/or critical mode. The project has started on April 01, 2009 for a period of three years. In this paper, we present the latest configuration of the reactor core and primary system. The FASTEF facility has evolved quite a lot since the intermediate reporting done at the ICAPP'10 and ICAPP'11 conferences 1 2. If it remains a small-scale facility, the core power amounts now up to 100 MWth in critical mode. In a companion paper 3, we present the concept of the reactor building and the plant layout. (authors)

  9. Superstring theory in AdS(3) and plane waves

    NASA Astrophysics Data System (ADS)

    Son, John Sang Won

    This thesis is devoted to the study of string theory in AdS 3 and its applications to recent developments in string theory. The difficulties associated with formulating a consistent string theory in AdS3 and its underlying SL(2, R) WZW model are explained. We describe how these difficulties can be overcome by assuming that the SL(2, R) WZW model contains spectral flow symmetry. The existence of spectral flow symmetry in the fully quantum treatment is proved by a calculation of the one-loop string partition function. We consider Euclidean AdS 3 with the time direction periodically identified, and compute the torus partition function in this background. The string spectrum can be reproduced by viewing the one-loop calculation as the free energy of a gas of strings, thus providing a rigorous proof of the results based on spectral flow arguments. Next, we turn to spacetimes that are quotients of AdS 3, which include the BTZ black hole and conical spaces. Strings propagating in the conical space are described by taking an orbifold of strings in AdS3. We show that the twisted states of these orbifolds can be obtained by fractional spectral flow. We show that the shift in the ground state energy usually associated with orbifold twists is absent in this case, and offer a unified framework in which to view spectral flow. Lastly, we consider the RNS superstrings in AdS 3 x S3 x M , where M may be K3 or T 4, based on supersymmetric extensions of SL(2, R) and SU(2) WZW models. We construct the physical states and calculate the spectrum. A subsector of this theory describes strings propagating in the six dimensional plane wave obtained by the Penrose limit of AdS3 x S3 x M . We reproduce the plane wave spectrum by taking J and the radius to infinity. We show that the plane wave spectrum actually coincides with the large J spectrum at fixed radius, i.e. in AdS3 x S3. Relation to some recent topics of interest such as the Frolov-Tseytlin string and strings with critical tension

  10. Value-Added Modeling in Physical Education

    ERIC Educational Resources Information Center

    Hushman, Glenn; Hushman, Carolyn

    2015-01-01

    The educational reform movement in the United States has resulted in a variety of states moving toward a system of value-added modeling (VAM) to measure a teacher's contribution to student achievement. Recently, many states have begun using VAM scores as part of a larger system to evaluate teacher performance. In the past decade, only "core…

  11. Entanglement entropy for free scalar fields in AdS

    NASA Astrophysics Data System (ADS)

    Sugishita, Sotaro

    2016-09-01

    We compute entanglement entropy for free massive scalar fields in anti-de Sitter (AdS) space. The entangling surface is a minimal surface whose boundary is a sphere at the boundary of AdS. The entropy can be evaluated from the thermal free energy of the fields on a topological black hole by using the replica method. In odd-dimensional AdS, exact expressions of the Rényi entropy S n are obtained for arbitrary n. We also evaluate 1-loop corrections coming from the scalar fields to holographic entanglement entropy. Applying the results, we compute the leading difference of entanglement entropy between two holographic CFTs related by a renormalization group flow triggered by a double trace deformation. The difference is proportional to the shift of a central charge under the flow.

  12. Asymptotically AdS spacetimes with a timelike Kasner singularity

    NASA Astrophysics Data System (ADS)

    Ren, Jie

    2016-07-01

    Exact solutions to Einstein's equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution's appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.

  13. New massive gravity and AdS(4) counterterms.

    PubMed

    Jatkar, Dileep P; Sinha, Aninda

    2011-04-29

    We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory. PMID:21635026

  14. Detailed ultraviolet asymptotics for AdS scalar field perturbations

    NASA Astrophysics Data System (ADS)

    Evnin, Oleg; Jai-akson, Puttarak

    2016-04-01

    We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.

  15. Holography and AdS4 self-gravitating dyons

    NASA Astrophysics Data System (ADS)

    Lugo, A. R.; Moreno, E. F.; Schaposnik, F. A.

    2010-11-01

    We present a self-gravitating dyon solution of the Einstein-Yang-Mills-Higgs equations of motion in asymptotically AdS space. The back reaction of gauge and Higgs fields on the space-time geometry leads to the metric of an asymptotically AdS black hole. Using the gauge/gravity correspondence we analyze relevant properties of the finite temperature quantum field theory defined on the boundary. In particular we identify an order operator, characterize a phase transition of the dual theory on the border and also compute the expectation value of the finite temperature Wilson loop.

  16. AdS box graphs, unitarity and operator product expansions

    NASA Astrophysics Data System (ADS)

    Hoffmann, L.; Mesref, L.; Rühl, W.

    2000-11-01

    We develop a method of singularity analysis for conformal graphs which, in particular, is applicable to the holographic image of AdS supergravity theory. It can be used to determine the critical exponents for any such graph in a given channel. These exponents determine the towers of conformal blocks that are exchanged in this channel. We analyze the scalar AdS box graph and show that it has the same critical exponents as the corresponding CFT box graph. Thus pairs of external fields couple to the same exchanged conformal blocks in both theories. This is looked upon as a general structural argument supporting the Maldacena hypothesis.

  17. Phases of global AdS black holes

    NASA Astrophysics Data System (ADS)

    Basu, Pallab; Krishnan, Chethan; Subramanian, P. N. Bala

    2016-06-01

    We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ( AdS 4) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.

  18. Maintenance information: value added?

    SciTech Connect

    Tomlingson, P.D.

    2005-11-01

    A study of how well the mining industry uses information management systems for maintenance suggests there's plenty of room for improvement. The article presents results of a study of 13 mining and mineral processing operations over a four year period combined with a questionnaire completed by 91 attendees at seminars. None of the organizations had a well-defined, documented maintenance program and consequently were not able to use information effectively. Packaged information system providers did not recognise that industrial maintenance organizations had different information needs.

  19. Value added data archiving

    NASA Technical Reports Server (NTRS)

    Berard, Peter R.

    1993-01-01

    Researchers in the Molecular Sciences Research Center (MSRC) of Pacific Northwest Laboratory (PNL) currently generate massive amounts of scientific data. The amount of data that will need to be managed by the turn of the century is expected to increase significantly. Automated tools that support the management, maintenance, and sharing of this data are minimal. Researchers typically manage their own data by physically moving datasets to and from long term storage devices and recording a dataset's historical information in a laboratory notebook. Even though it is not the most efficient use of resources, researchers have tolerated the process. The solution to this problem will evolve over the next three years in three phases. PNL plans to add sophistication to existing multilevel file system (MLFS) software by integrating it with an object database management system (ODBMS). The first phase in the evolution is currently underway. A prototype system of limited scale is being used to gather information that will feed into the next two phases. This paper describes the prototype system, identifies the successes and problems/complications experienced to date, and outlines PNL's long term goals and objectives in providing a permanent solution.

  20. Radiation effects in materials for accelerator-driven neutron technologies

    SciTech Connect

    Wechsler, M.S.; Lin, C.; Sommer, W.F.; Daemen, L.L.; Ferguson, P.D.

    1997-03-01

    The materials exposed to the most damaging radiation environments in an SNS (spallation neutron source) are those in the path of the incident proton beam. This includes target and window materials. These materials will experience damage from the incident protons and the spallation neutrons. The major solid targets in operating SNS`s and under consideration for the 1--5 MW SNS`s are W, U, and Pb. Tungsten is the target material at LANSCE, and is the project target material for an upgraded LANSCE target that is presently being designed. It is also the projected target material for the tritium producing SNS under design at LANL. In this paper, the authors present the results of spallation radiation damage calculations (displacement and He production) for tungsten.

  1. Accelerator-driven transmutation of spent fuel elements

    DOEpatents

    Venneri, Francesco; Williamson, Mark A.; Li, Ning

    2002-01-01

    An apparatus and method is described for transmuting higher actinides, plutonium and selected fission products in a liquid-fuel subcritical assembly. Uranium may also be enriched, thereby providing new fuel for use in conventional nuclear power plants. An accelerator provides the additional neutrons required to perform the processes. The size of the accelerator needed to complete fuel cycle closure depends on the neutron efficiency of the supported reactors and on the neutron spectrum of the actinide transmutation apparatus. Treatment of spent fuel from light water reactors (LWRs) using uranium-based fuel will require the largest accelerator power, whereas neutron-efficient high temperature gas reactors (HTGRs) or CANDU reactors will require the smallest accelerator power, especially if thorium is introduced into the newly generated fuel according to the teachings of the present invention. Fast spectrum actinide transmutation apparatus (based on liquid-metal fuel) will take full advantage of the accelerator-produced source neutrons and provide maximum utilization of the actinide-generated fission neutrons. However, near-thermal transmutation apparatus will require lower standing

  2. Dogs lap using acceleration-driven open pumping

    PubMed Central

    Gart, Sean; Socha, John J.; Vlachos, Pavlos P.; Jung, Sunghwan

    2015-01-01

    Dogs lap because they have incomplete cheeks and cannot suck. When lapping, a dog’s tongue pulls a liquid column from the bath, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured lapping in 19 dogs and used the results to generate a physical model of the tongue’s interaction with the air–fluid interface. These experiments help to explain how dogs exploit the fluid dynamics of the generated column. The results demonstrate that effects of acceleration govern lapping frequency, which suggests that dogs curl the tongue to create a larger liquid column. Comparing lapping in dogs and cats reveals that, despite similar morphology, these carnivores lap in different physical regimes: an unsteady inertial regime for dogs and steady inertial regime for cats. PMID:26668382

  3. Dogs lap using acceleration-driven open pumping.

    PubMed

    Gart, Sean; Socha, John J; Vlachos, Pavlos P; Jung, Sunghwan

    2015-12-29

    Dogs lap because they have incomplete cheeks and cannot suck. When lapping, a dog's tongue pulls a liquid column from the bath, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured lapping in 19 dogs and used the results to generate a physical model of the tongue's interaction with the air-fluid interface. These experiments help to explain how dogs exploit the fluid dynamics of the generated column. The results demonstrate that effects of acceleration govern lapping frequency, which suggests that dogs curl the tongue to create a larger liquid column. Comparing lapping in dogs and cats reveals that, despite similar morphology, these carnivores lap in different physical regimes: an unsteady inertial regime for dogs and steady inertial regime for cats.

  4. Laser plasma accelerator driven by a super-Gaussian pulse

    NASA Astrophysics Data System (ADS)

    Ostermayr, Tobias; Petrovics, Stefan; Iqbal, Khalid; Klier, Constantin; Ruhl, Hartmut; Nakajima, Kazuhisa; Deng, Aihua; Zhang, Xiaomei; Shen, Baifei; Liu, Jiansheng; Li, Ruxin; Xu, Zhizhan; Tajima, Toshiki; Tajima

    2012-08-01

    A laser wakefield accelerator (LWFA) with a weak focusing force is considered to seek improved beam quality in LWFA. We employ super-Gaussian laser pulses to generate the wakefield and study the behavior of the electron beam dynamics and synchrotron radiation arising from the transverse betatron oscillations through analysis and computation. We note that the super-Gaussian wakefields radically reduce the betatron oscillations and make the electron orbits mainly ballistic over a single stage. This feature permits to obtain small emittance and thus high luminosity, while still benefitting from the low-density operation of LWFA (Nakajima et al. 2011 Phys. Rev. ST Accel. Beams 14, 091301), such as the reduced radiation loss, less number of stages, less beam instabilities, and less required wall plug power than in higher density regimes.

  5. D-branes on AdS flux compactifications

    NASA Astrophysics Data System (ADS)

    Koerber, Paul; Martucci, Luca

    2008-01-01

    We study D-branes in Script N = 1 flux compactifications to AdS4. We derive their supersymmetry conditions and express them in terms of background generalized calibrations. Basically because AdS has a boundary, the analysis of stability is more subtle and qualitatively different from the usual case of Minkowski compactifications. For instance, stable D-branes filling AdS4 may wrap trivial internal cycles. Our analysis gives a geometric realization of the four-dimensional field theory approach of Freedman and collaborators. Furthermore, the one-to-one correspondence between the supersymmetry conditions of the background and the existence of generalized calibrations for D-branes is clarified and extended to any supersymmetric flux background that admits a time-like Killing vector and for which all fields are time-independent with respect to the associated time. As explicit examples, we discuss supersymmetric D-branes on IIA nearly Kähler AdS4 flux compactifications.

  6. Dyonic AdS black holes from magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Caldarelli, Marco M.; Dias, Óscar J. C.; Klemm, Dietmar

    2009-03-01

    We use the AdS/CFT correspondence to argue that large dyonic black holes in anti-de Sitter spacetime are dual to stationary solutions of the equations of relativistic magnetohydrodynamics on the conformal boundary of AdS. The dyonic Kerr-Newman-AdS4 solution corresponds to a charged diamagnetic fluid not subject to any net Lorentz force, due to orthogonal magnetic and electric fields compensating each other. The conserved charges, stress tensor and R-current of the fluid are shown to be in exact agreement with the corresponding quantities of the black hole. Furthermore, we obtain stationary solutions of the Navier-Stokes equations in four dimensions, which yield predictions for (yet to be constructed) charged rotating black strings in AdS5 carrying nonvanishing momentum along the string. Finally, we consider Scherk-Schwarz reduced AdS gravity on a circle. In this theory, large black holes and black strings are dual to lumps of deconfined plasma of the associated CFT. We analyze the effects that a magnetic field introduces in the Rayleigh-Plateau instability of a plasma tube, which is holographically dual to the Gregory-Laflamme instability of a magnetically charged black string.

  7. AdS Branes from Partial Breaking of Superconformal Symmetries

    SciTech Connect

    Ivanov, E.A.

    2005-10-01

    It is shown how the static-gauge world-volume superfield actions of diverse superbranes on the AdS{sub d+1} superbackgrounds can be systematically derived from nonlinear realizations of the appropriate AdS supersymmetries. The latter are treated as superconformal symmetries of flat Minkowski superspaces of the bosonic dimension d. Examples include the N = 1 AdS{sub 4} supermembrane, which is associated with the 1/2 partial breaking of the OSp(1|4) supersymmetry down to the N = 1, d = 3 Poincare supersymmetry, and the T-duality related L3-brane on AdS{sub 5} and scalar 3-brane on AdS{sub 5} x S{sup 1}, which are associated with two different patterns of 1/2 breaking of the SU(2, 2|1) supersymmetry. Another (closely related) topic is the AdS/CFT equivalence transformation. It maps the world-volume actions of the codimension-one AdS{sub d+1} (super)branes onto the actions of the appropriate Minkowski (super)conformal field theories in the dimension d.

  8. Worldsheet dilatation operator for the AdS superstring

    NASA Astrophysics Data System (ADS)

    Ramírez, Israel; Vallilo, Brenno Carlini

    2016-05-01

    In this work we propose a systematic way to compute the logarithmic divergences of composite operators in the pure spinor description of the AdS 5 × S 5 superstring. The computations of these divergences can be summarized in terms of a dilatation operator acting on the local operators. We check our results with some important composite operators of the formalism.

  9. Entanglement temperature and perturbed AdS3 geometry

    NASA Astrophysics Data System (ADS)

    Levine, G. C.; Caravan, B.

    2016-06-01

    Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .

  10. A novel solar bi-ejector refrigeration system and the performance of the added injector with different structures and operation parameters

    SciTech Connect

    Wang, Fei; Shen, Shengqiang

    2009-12-15

    A novel solar bi-ejector refrigeration system was investigated, whose difference compared to the traditional system is that the circulation pump is replaced by a thermal injector. The new system works more stably and needs less maintenance work than the old one, and the whole system can more fully utilize the solar energy. The mathematical models for calculating the performance of the injector and the whole solar refrigeration system were established. The pressure rise performance of injector under different structure and operation parameters and the performance of solar bi-ejector refrigeration system were studied with R123. The results show that the discharged pressure of injector is affected by structure dimensions of injector and operation conditions. With increasing generation temperature, the entrainment ratio of ejector becomes better while that of injector becomes worse and the overall thermal efficiency of the solar bi-ejector refrigeration system first increases and then decreases with an optimum value of 0.132 at generation temperature of 105 C, condensation temperature of 35 C and evaporation temperature of 10 C. (author)

  11. Effective Ad-Hoc Committees.

    ERIC Educational Resources Information Center

    Young, David G.

    1983-01-01

    Ad-hoc committees may be symbolic, informational, or action committees. A literature survey indicates such committees' structural components include a suprasystem and three subsystems involving linkages, production, and implementation. Other variables include size, personal factors, and timing. All the factors carry implications about ad-hoc…

  12. Lorentzian AdS geometries, wormholes, and holography

    SciTech Connect

    Arias, Raul E.; Silva, Guillermo A.; Botta Cantcheff, Marcelo

    2011-03-15

    We investigate the structure of two-point functions for the quantum field theory dual to an asymptotically Lorentzian Anti de Sitter (AdS) wormhole. The bulk geometry is a solution of five-dimensional second-order Einstein-Gauss-Bonnet gravity and causally connects two asymptotically AdS spacetimes. We revisit the Gubser-Klebanov-Polyakov-Witten prescription for computing two-point correlation functions for dual quantum field theories operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values {phi}{sub 0}{sup {+-}} at each of the two asymptotic AdS regions; along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O{sup {+-}} and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom living at each boundary. The AdS{sub 1+1} geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a very simple geometric criterion to distinguish coupling from entanglement effects among two sets of degrees of freedom associated with each of the disconnected parts of the boundary.

  13. One-loop diagrams in AdS space

    SciTech Connect

    Hung Lingyan; Shang Yanwen

    2011-01-15

    We study the complex scalar loop corrections to the boundary-boundary gauge two-point function in pure AdS space in Poincare coordinates, in the presence of boundary quadratic perturbations to the scalar. These perturbations correspond to double-trace perturbations in the dual CFT and modify the boundary conditions of the bulk scalars in AdS. We find that, in addition to the usual UV divergences, the one-loop calculation suffers from a divergence originating in the limit as the loop vertices approach the AdS horizon. We show that this type of divergence is independent of the boundary coupling; making use of this we extract the finite relative variation of the imaginary part of the loop via Cutkosky rules as the boundary perturbation varies. Applying our methods to compute the effects of a time-dependent impurity to the conductivities using the replica trick in AdS/CFT, we find that generally an IR-relevant disorder reduces the conductivity and that in the extreme low frequency limit the correction due to the impurities overwhelms the planar CFT result even though it is supposedly 1/N{sup 2} suppressed. We also comment on the more physical scenario of a time-independent impurity.

  14. Offset compensation for A/D converters

    NASA Technical Reports Server (NTRS)

    Brokl, S. S.; Hurd, W. J.

    1979-01-01

    Analog-to-digital (A/D) converter eliminates dc offset in final digitized signal as well as in analog input by using digital feedback for compensation. Circuit could prove useful in data processing applications in which analog-format data are entered at high rates, as in point-of-sale data input systems.

  15. Cutting Budget Corners While Adding Value.

    ERIC Educational Resources Information Center

    Veile, Craig N.; Carpenter, Mark J.

    2000-01-01

    Discusses how one school district saved money while adding long- term value to its capital improvement project. Planning issues involving square footage requirements, quality of material to be used, and heating and cooling system selection are discussed as are concepts to increase student learning capacity for the same construction dollars. (GR)

  16. Renormalization, averaging, conservation laws and AdS (in)stability

    NASA Astrophysics Data System (ADS)

    Craps, Ben; Evnin, Oleg; Vanhoof, Joris

    2015-01-01

    We continue our analytic investigations of non-linear spherically symmetric perturbations around the anti-de Sitter background in gravity-scalar field systems, and focus on conservation laws restricting the (perturbatively) slow drift of energy between the different normal modes due to non-linearities. We discover two conservation laws in addition to the energy conservation previously discussed in relation to AdS instability. A similar set of three conservation laws was previously noted for a self-interacting scalar field in a non-dynamical AdS background, and we highlight the similarities of this system to the fully dynamical case of gravitational instability. The nature of these conservation laws is best understood through an appeal to averaging methods which allow one to derive an effective Lagrangian or Hamiltonian description of the slow energy transfer between the normal modes. The conservation laws in question then follow from explicit symmetries of this averaged effective theory.

  17. Kolmogorov-Zakharov spectrum in AdS gravitational collapse.

    PubMed

    de Oliveira, H P; Pando Zayas, Leopoldo A; Rodrigues, E L

    2013-08-01

    We study black hole formation during the gravitational collapse of a massless scalar field in asymptotically D-dimensional anti-de Sitter AdS(D) spacetimes for D = 4, 5. We conclude that spherically symmetric gravitational collapse in asymptotically AdS spaces is turbulent and characterized by a Kolmogorov-Zakharov spectrum. Namely, we find that after an initial period of weakly nonlinear evolution, there is a regime where the power spectrum of the Ricci scalar evolves as ω(-s) with the frequency, ω, and s ≈ 1.7 ± 0.1.

  18. Experimental Signature of Microheterogeneity in Ionic Liquid-H2 O Systems and Their Perturbation by Adding Li(+) Salts: A Pulsed Gradient Spin-Echo NMR Approach.

    PubMed

    Nanda, Raju; Rajamohanan, P R; Kumar, Anil

    2015-10-01

    Distinct microheterogeneity has been observed in the [OMIM]Br-H2 O system, which is interestingly perturbed by the addition of Li(+) salts, indicating unusual diffusivity of [OMIM]Br and H2 O molecules. However, the diffusional dynamics of water clusters show contrasting salting behavior at higher concentrations of Li(+) salts, following the classical salting phenomenon in lower amounts. In contrast, the existing microheterogeneity in the [BMIM]Br-H2 O system is weak enough to show any perturbation caused by the Li(+) salts on the NMR time scale.

  19. Experimental Signature of Microheterogeneity in Ionic Liquid-H2 O Systems and Their Perturbation by Adding Li(+) Salts: A Pulsed Gradient Spin-Echo NMR Approach.

    PubMed

    Nanda, Raju; Rajamohanan, P R; Kumar, Anil

    2015-10-01

    Distinct microheterogeneity has been observed in the [OMIM]Br-H2 O system, which is interestingly perturbed by the addition of Li(+) salts, indicating unusual diffusivity of [OMIM]Br and H2 O molecules. However, the diffusional dynamics of water clusters show contrasting salting behavior at higher concentrations of Li(+) salts, following the classical salting phenomenon in lower amounts. In contrast, the existing microheterogeneity in the [BMIM]Br-H2 O system is weak enough to show any perturbation caused by the Li(+) salts on the NMR time scale. PMID:26300328

  20. REMOVAL OF ADDED NITRATE IN THE SINGLE, BINARY, AND TERNARY SYSTEMS OF COTTON BURR COMPOST, ZEROVALENT IRON, AND SEDIMENT: IMPLICATIONS FOR GROUNDWATER NITRATE REMEDIATION USING PERMEABLE REACTIVE BARRIERS

    EPA Science Inventory

    Recent research has shown that carbonaceous solid materials and zerovalent iron (Fe0) may potentially be used as media in permeable reactive barriers (PRBs) to degrade groundwater nitrate via heterotrophic denitrification in the solid carbon system, and via abiotic reduction and ...

  1. Three-vector system for high-level functional expression of value-added co-products with xylose isomerase and xylulokinase in an industrial saccharomyces cerevisiae strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The three-plasmid yeast expression system utilizing the portable small ubiquitin-like modifier (SUMO) vector set combined with the efficient endogenous yeast protease rapidly produces large amounts of soluble functional protein. It provides high levels of expression for three different proteins sim...

  2. The added value of user involvement during the development of a feedback system regarding physical functioning for community-dwelling elderly people

    PubMed Central

    Vermeulen, Joan; Neyens, Jacques C. L; Spreeuwenberg, Marieke D; Van Rossum, Erik; Hewson, David; De Witte, Luc P

    2012-01-01

    Background The number of frail elderly people is increasing. Unfortunately, the number of caregivers is not increasing at the same pace, which affects older people, caregivers and healthcare systems. Because of these developments, self-management is becoming more important in healthcare. To support community-dwelling elderly people in their self-management, a system was developed that monitors their physical functioning. This system provides feedback to elderly people and their caregivers regarding physical indicators of frailty. The feedback is provided to elderly people via the screen of a mobile phone. It is important that elderly people understand the content of the feedback and are able to use the mobile phone properly. If not, it is unlikely that the system can support self-management. Many interactive health technologies that have been developed do not fulfil their promises. An important reason for this is that human and other non-technology issues are not sufficiently taken into consideration during the development process. Objective To collaborate with elderly people during the development and evaluation of a feedback system for community-dwelling elderly people regarding physical functioning. Methods An iterative user-centered design that consists of five phases was used to develop and evaluate the feedback system. These five phases were: 1) Selection of users, 2) Analysis of users and their context, 3) Identification of user needs, 4) Development of a prototype, and 5) Evaluation of the prototype. Three representatives of a target group panel for elderly people were selected in phase 1. They shared their needs and preferences during three expert group meetings that took place during the development process. This resulted in the development of a prototype which was first evaluated in a heuristic evaluation. Once adjustments were made, 11 elderly people evaluated the adjusted prototype using a think aloud procedure. They rated the usability and

  3. Semiclassical Virasoro blocks from AdS3 gravity

    NASA Astrophysics Data System (ADS)

    Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River

    2015-12-01

    We present a unified framework for the holographic computation of Virasoro conformal blocks at large central charge. In particular, we provide bulk constructions that correctly reproduce all semiclassical Virasoro blocks that are known explicitly from conformal field theory computations. The results revolve around the use of geodesic Witten diagrams, recently introduced in [1], evaluated in locally AdS3 geometries generated by backreaction of heavy operators. We also provide an alternative computation of the heavy-light semiclassical block — in which two external operators become parametrically heavy — as a certain scattering process involving higher spin gauge fields in AdS3; this approach highlights the chiral nature of Virasoro blocks. These techniques may be systematically extended to compute corrections to these blocks and to interpolate amongst the different semiclassical regimes.

  4. AdS6 solutions of type II supergravity

    NASA Astrophysics Data System (ADS)

    Apruzzi, Fabio; Fazzi, Marco; Passias, Achilleas; Rosa, Dario; Tomasiello, Alessandro

    2014-11-01

    Very few AdS6 × M 4 supersymmetric solutions are known: one in massive IIA, and two IIB solutions dual to it. The IIA solution is known to be unique; in this paper, we use the pure spinor approach to give a classification for IIB supergravity. We reduce the problem to two PDEs on a two-dimensional space Σ. M 4 is then a fibration of S 2 over Σ; the metric and fluxes are completely determined in terms of the solution to the PDEs. The results seem likely to accommodate near-horizon limits of ( p, q)-fivebrane webs studied in the literature as a source of CFT5's. We also show that there are no AdS6 solutions in eleven-dimensional supergravity.

  5. Th and U fuel photofission study by NTD for AD-MSR subcritical assembly

    SciTech Connect

    Sajo-Bohus, Laszlo; Greaves, Eduardo D.; Barros, Haydn; Pino, Felix; Barrera, Maria T.; Farina, Fulvio; Davila, Jesus

    2015-07-23

    During the last decade a considerable effort has been devoted for developing energy generating systems based on advanced nuclear technology within the design concepts of GEN-IV. Thorium base fuel systems such as accelerator driven nuclear reactors are one of the often mentioned attractive and affordable options. Several radiotherapy linear accelerators are on the market and due to their reliability, they could be employed as drivers for subcritical liquid fuel assemblies. Bremsstrahlung photons with energies above 5.5MeV, induce (γ,n) and (e,e’n) reactions in the W-target. Resulting gamma radiation and photo or fission neutrons may be absorbed in target materials such as thorium and uranium isotopes to induce sustained fission or nuclear transmutation in waste radioactive materials. Relevant photo driven and photo-fission reaction cross sections are important for actinides {sup 232}Th, {sup 238}U and {sup 237}Np in the radiotherapy machines energy range of 10-20 MV. In this study we employ passive nuclear track detectors (NTD) to determine fission rates and neutron production rates with the aim to establish the feasibility for gamma and photo-neutron driven subcritical assemblies. To cope with these objectives a 20 MV radiotherapy machine has been employed with a mixed fuel target. Results will support further development for a subcritical assembly employing a thorium containing liquid fuel. It is expected that acquired technological knowledge will contribute to the Venezuelan nuclear energy program.

  6. Th and U fuel photofission study by NTD for AD-MSR subcritical assembly

    NASA Astrophysics Data System (ADS)

    Sajo-Bohus, Laszlo; Greaves, Eduardo D.; Davila, Jesus; Barros, Haydn; Pino, Felix; Barrera, Maria T.; Farina, Fulvio

    2015-07-01

    During the last decade a considerable effort has been devoted for developing energy generating systems based on advanced nuclear technology within the design concepts of GEN-IV. Thorium base fuel systems such as accelerator driven nuclear reactors are one of the often mentioned attractive and affordable options. Several radiotherapy linear accelerators are on the market and due to their reliability, they could be employed as drivers for subcritical liquid fuel assemblies. Bremsstrahlung photons with energies above 5.5MeV, induce (γ,n) and (e,e'n) reactions in the W-target. Resulting gamma radiation and photo or fission neutrons may be absorbed in target materials such as thorium and uranium isotopes to induce sustained fission or nuclear transmutation in waste radioactive materials. Relevant photo driven and photo-fission reaction cross sections are important for actinides 232Th, 238U and 237Np in the radiotherapy machines energy range of 10-20 MV. In this study we employ passive nuclear track detectors (NTD) to determine fission rates and neutron production rates with the aim to establish the feasibility for gamma and photo-neutron driven subcritical assemblies. To cope with these objectives a 20 MV radiotherapy machine has been employed with a mixed fuel target. Results will support further development for a subcritical assembly employing a thorium containing liquid fuel. It is expected that acquired technological knowledge will contribute to the Venezuelan nuclear energy program.

  7. Computing and Using Metrics in the ADS

    NASA Astrophysics Data System (ADS)

    Henneken, E. A.; Accomazzi, A.; Kurtz, M. J.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Holachek, A.; Murray, S. S.

    2015-04-01

    Finding measures for research impact, be it for individuals, institutions, instruments, or projects, has gained a lot of popularity. There are more papers written than ever on new impact measures, and problems with existing measures are being pointed out on a regular basis. Funding agencies require impact statistics in their reports, job candidates incorporate them in their resumes, and publication metrics have even been used in at least one recent court case. To support this need for research impact indicators, the SAO/NASA Astrophysics Data System (ADS) has developed a service that provides a broad overview of various impact measures. In this paper we discuss how the ADS can be used to quench the thirst for impact measures. We will also discuss a couple of the lesser-known indicators in the metrics overview and the main issues to be aware of when compiling publication-based metrics in the ADS, namely author name ambiguity and citation incompleteness.

  8. Conserved higher-spin charges in AdS4

    NASA Astrophysics Data System (ADS)

    Gelfond, O. A.; Vasiliev, M. A.

    2016-03-01

    Gauge invariant conserved conformal currents built from massless fields of all spins in 4d Minkowski space-time and AdS4 are described in the unfolded dynamics approach. The current cohomology associated with non-zero conserved charges is found. The resulting list of charges is shown to match the space of parameters of the conformal higher-spin symmetry algebra in four dimensions.

  9. On information loss in AdS3/CFT2

    DOE PAGES

    Fitzpatrick, A. Liam; Kaplan, Jared; Li, Daliang; Wang, Junpu

    2016-05-18

    We discuss information loss from black hole physics in AdS3, focusing on two sharp signatures infecting CFT2 correlators at large central charge c: ‘forbidden singularities’ arising from Euclidean-time periodicity due to the effective Hawking temperature, and late-time exponential decay in the Lorentzian region. We study an infinite class of examples where forbidden singularities can be resolved by non-perturbative effects at finite c, and we show that the resolution has certain universal features that also apply in the general case. Analytically continuing to the Lorentzian regime, we find that the non-perturbative effects that resolve forbidden singularities qualitatively change the behavior ofmore » correlators at times t ~SBH, the black hole entropy. This may resolve the exponential decay of correlators at late times in black hole backgrounds. By Borel resumming the 1/c expansion of exact examples, we explicitly identify ‘information-restoring’ effects from heavy states that should correspond to classical solutions in AdS3. Lastly, our results suggest a line of inquiry towards a more precise formulation of the gravitational path integral in AdS3.« less

  10. Extensions to Dynamic System Simulation of Fissile Solution Systems

    SciTech Connect

    Klein, Steven Karl; Bernardin, John David; Kimpland, Robert Herbert; Spernjak, Dusan

    2015-08-24

    Previous reports have documented the results of applying dynamic system simulation (DSS) techniques to model a variety of fissile solution systems. The SUPO (Super Power) aqueous homogeneous reactor (AHR) was chosen as the benchmark for comparison of model results to experimental data for steadystate operation.1 Subsequently, DSS was applied to additional AHR to verify results obtained for SUPO and extend modeling to prompt critical excursions, ramp reactivity insertions of various magnitudes and rate, and boiling operations in SILENE and KEWB (Kinetic Experiment Water Boiler).2 Additional models for pressurized cores (HRE: Homogeneous Reactor Experiment), annular core geometries, and accelerator-driven subcritical systems (ADAHR) were developed and results reported.3 The focus of each of these models is core dynamics; neutron kinetics, thermal hydraulics, radiolytic gas generation and transport are coupled to examine the time-based evolution of these systems from start-up through transition to steady-state. A common characteristic of these models is the assumption that (a) core cooling system inlet temperature and flow and (b) plenum gas inlet pressure and flow are held constant; no external (to core) component operations that may result in dynamic change to these parameters are considered. This report discusses extension of models to include explicit reference to cooling structures and radiolytic gas handling. The accelerator-driven subcritical generic system model described in References 3 and 4 is used as a basis for this extension.

  11. 48 CFR 453.303-838 - Purchase Order (AD-838).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Purchase Order (AD-838). 453.303-838 Section 453.303-838 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CLAUSES AND FORMS FORMS Illustrations of Forms 453.303-838 Purchase Order (AD-838)....

  12. 48 CFR 453.303-700 - Procurement Request (AD-700).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Procurement Request (AD-700). 453.303-700 Section 453.303-700 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CLAUSES AND FORMS FORMS Illustrations of Forms 453.303-700 Procurement Request (AD-700)....

  13. 48 CFR 453.303-838 - Purchase Order (AD-838).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Purchase Order (AD-838). 453.303-838 Section 453.303-838 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CLAUSES AND FORMS FORMS Illustrations of Forms 453.303-838 Purchase Order (AD-838)....

  14. ADS/CFT and QCD

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U. /SLAC

    2007-02-21

    The AdS/CFT correspondence between string theory in AdS space and conformal .eld theories in physical spacetime leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. Although QCD is not conformally invariant, one can nevertheless use the mathematical representation of the conformal group in five-dimensional anti-de Sitter space to construct a first approximation to the theory. The AdS/CFT correspondence also provides insights into the inherently non-perturbative aspects of QCD, such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of AdS space z and a specific impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties and allow the computation of decay constants, form factors, and other exclusive scattering amplitudes. New relativistic lightfront equations in ordinary space-time are found which reproduce the results obtained using the 5-dimensional theory. The effective light-front equations possess remarkable algebraic structures and integrability properties. Since they are complete and orthonormal, the AdS/CFT model wavefunctions can also be used as a basis for the diagonalization of the full light-front QCD Hamiltonian, thus systematically improving the AdS/CFT approximation.

  15. Climate, Hydrochemistry and Economics of Surface-water Systems (CHESS): adding a European dimension to the catchment modelling experience developed under LOIS.

    PubMed

    Boorman, David B

    2003-10-01

    One achievement of the UK Land-Ocean Interaction Study (LOIS) was to link dynamic biogeochemical models of different domains, e.g. rivers, estuaries and coastal waters, and to use the linked model to investigate possible changes from the current status that might occur in the future, for example as the result of climate change. The Climate, Hydrochemistry and Economics of Surface-water Systems (CHESS) project has taken the LOIS methodology forward by exploring possible impacts of climate change on the water quality of European rivers, with the purpose of informing future catchment management. This was achieved by the application of a standard modelling framework to a set of five European catchments located in Finland (River Vantaa), United Kingdom (Yorkshire Ouse), Belgium (Dender), Italy (Enza) and Greece (Pinios). Baseline conditions were simulated using existing meteorological data from the period 1961-1990, and in all cases the modelling framework was able to reproduce key features of the flow and water quality regimes of the study catchments. The modelling framework comprised two models. The Soil Water Assessment Tool (SWAT) was used to simulate water and chemical fluxes, primarily nutrients and sediment, generated from diffuse areas and thereby provide sub-catchment inputs to an in-stream water quality model, the Quality Evaluation and Simulation Tool for River Systems (QUESTOR). QUESTOR integrated the diffuse runoff along the channel network, together with point source discharges from industry and sewage treatment works, and water abstractions for public supply, industry and agriculture. The modelling framework has been used for the baseline conditions, along with a set of six climate scenarios. These comprised four scenarios derived from different general circulation models (GCMs) representing the 2050s, and three scenarios from the same GCM representing the 2020s, 2050s and 2080s, with one scenario in both groups. Results have been explored using a range

  16. Impact of Cranial Irradiation Added to Intrathecal Conditioning in Hematopoietic Cell Transplantation in Adult Acute Myeloid Leukemia With Central Nervous System Involvement

    SciTech Connect

    Mayadev, Jyoti S.; Douglas, James G.; Storer, Barry E.; Appelbaum, Frederick R.; Storb, Rainer

    2011-05-01

    Purpose: Neither the prognostic importance nor the appropriate management of central nervous system (CNS) involvement is known for patients with acute myeloid leukemia (AML) undergoing hematopoietic cell transplantation (HCT). We examined the impact of a CNS irradiation boost to standard intrathecal chemotherapy (ITC). Methods and Materials: From 1995 to 2005, a total of 648 adult AML patients received a myeloablative HCT: 577 patients were CNS negative (CNS-), and 71 were CNS positive (CNS+). Of the 71 CNS+ patients, 52 received intrathecal chemotherapy alone (CNS+ITC), and 19 received ITC plus an irradiation boost (CNS+RT). Results: The CNS-, CNS+ITC, and CNS+RT patients had 1- and 5-year relapse-free survivals (RFS) of 43% and 35%, 15% and 6%, and 37% and 32%, respectively. CNS+ITC patients had a statistically significant worse RFS compared with CNS- patients (hazard ratio [HR], 2.65; 95% confidence interval [CI], 2.0-3.6; p < 0.0001). CNS+RT patients had improved relapse free survival over that of CNS+ITC patients (HR, 0.45; 95% CI, 0.2-0.8; p = 0.01). The 1- and 5-year overall survivals (OS) of patients with CNS-, CNS+ITC, and CNS+RT, were 50% and 38%, 21% and 6%, and 53% and 42%, respectively. The survival of CNS+RT were significantly better than CNS+ITC patients (p = 0.004). After adjusting for known risk factors, CNS+RT patients had a trend toward lower relapse rates and reduced nonrelapse mortality. Conclusions: CNS+ AML is associated with a poor prognosis. The role of a cranial irradiation boost to intrathecal chemotherapy appears to mitigate the risk of CNS disease, and needs to be further investigated to define optimal treatment strategies.

  17. Euclidean and Noetherian entropies in AdS space

    SciTech Connect

    Dutta, Suvankar; Gopakumar, Rajesh

    2006-08-15

    We examine the Euclidean action approach, as well as that of Wald, to the entropy of black holes in asymptotically AdS spaces. From the point of view of holography these two approaches are somewhat complementary in spirit and it is not obvious why they should give the same answer in the presence of arbitrary higher derivative gravity corrections. For the case of the AdS{sub 5} Schwarzschild black hole, we explicitly study the leading correction to the Bekenstein-Hawking entropy in the presence of a variety of higher derivative corrections studied in the literature, including the Type IIB R{sup 4} term. We find a nontrivial agreement between the two approaches in every case. Finally, we give a general way of understanding the equivalence of these two approaches.

  18. Most general AdS3 boundary conditions

    NASA Astrophysics Data System (ADS)

    Grumiller, Daniel; Riegler, Max

    2016-10-01

    We consider the most general asymptotically anti-de Sitter boundary conditions in three-dimensional Einstein gravity with negative cosmological constant. The metric contains in total twelve independent functions, six of which are interpreted as chemical potentials (or non-normalizable fluctuations) and the other half as canonical boundary charges (or normalizable fluctuations). Their presence modifies the usual Fefferman-Graham expansion. The asymptotic symmetry algebra consists of two sl{(2)}_k current algebras, the levels of which are given by k = ℓ/(4 G N ), where ℓ is the AdS radius and G N the three-dimensional Newton constant.

  19. Entropy of near-extremal black holes in AdS5

    SciTech Connect

    Simon, Joan; Balasubramanian, Vijay; de Boer, Jan; Jejjala, Vishnu; Simon, Joan

    2007-07-24

    We construct the microstates of near-extremal black holes in AdS_5 x S5 as gases of defects distributed in heavy BPS operators in the dual SU(N) Yang-Mills theory. These defects describe open strings on spherical D3-branes in the S5, and we show that they dominate the entropy by directly enumerating them and comparing the results with a partition sum calculation. We display new decoupling limits in which the field theory of the lightest open strings on the D-branes becomes dual to a near-horizon region of the black hole geometry. In the single-charge black hole we find evidence for an infrared duality between SU(N) Yang-Mills theories that exchanges the rank of the gauge group with an R-charge. In the two-charge case (where pairs of branes intersect on a line), the decoupled geometry includes an AdS_3 factor with a two-dimensional CFT dual. The degeneracy in this CFT accounts for the black hole entropy. In the three-charge case (where triples of branes intersect at a point), the decoupled geometry contains an AdS_2 factor. Below a certain critical mass, the two-charge system displays solutions with naked timelike singularities even though they do not violate a BPS bound. We suggest a string theoretic resolution of these singularities.

  20. On elliptic string solutions in AdS3 and dS3

    NASA Astrophysics Data System (ADS)

    Bakas, Ioannis; Pastras, Georgios

    2016-07-01

    Classical string actions in AdS3 and dS3 can be connected to the sinh-Gordon and cosh-Gordon equations through Pohlmeyer reduction. We show that the problem of constructing a classical string solution with a given static or translationally invariant Pohlmeyer counterpart is equivalent to solving four pairs of effective Schrödinger problems. Each pair consists of a flat potential and an n = 1 Lamé potential whose eigenvalues are connected, and, additionally, the four solutions satisfy a set of constraints. An approach for solving this system is developed by employing an interesting connection between the specific class of classical string solutions and the band structure of the Lamé potential. This method is used for the construction of several families of classical string solutions, one of which turns out to be the spiky strings in AdS3. New solutions include circular rotating strings in AdS3 with singular time evolution of their radius and angular velocity as well as classical string solutions in dS3.

  1. Korean nova records in A.D. 1073 and A.D. 1074: R Aquarii

    NASA Astrophysics Data System (ADS)

    Yang, Hong-Jin; Park, Myeong-Gu; Cho, Se-Hyung; Park, Changbom

    2005-05-01

    R Aqr is known to be a symbiotic binary system with an associated extended emission nebula, possibly produced by a historic outburst. To find the associated historic records, we searched for and compiled all Guest Star and Peculiar Star records in three Korean official history books that cover almost two thousand years, Samguksagi, Goryeosa, Joseonwangjosillok. In addition to the record of A.D. 1073, previously noted by Li (1985, Chin. Astron. Astrophys., 9, 322), we have found in Goryeosa another candidate record of A.D. 1074, which has the same positional description as that of A.D. 1073 with an additional brightness description. We examined various aspects of the two records and conclude that they both are likely to be the records of outburst of R Aqr. This means that there were two successive outbursts in A.D. 1073 and in A.D. 1074, separated by approximately one year. Based on these records, we estimate the distance to R Aqr to be 273 pc if the expansion of the nebula has been at a constant rate. The brightness record of A.D. 1074 corresponds to the absolute magnitude at outburst of Moutburst = -6.2m -5.2m at this distance. The two Korean records associated with R Aqr may provide astronomically meaningful constraints to the outburst model of R Aqr and the formative process of its nebulosity.

  2. On AdS to dS transitions in higher-curvature gravity

    NASA Astrophysics Data System (ADS)

    Camanho, Xián O.; Edelstein, José D.; Gomberoff, Andrés; Sierra-Garcıa, J. Anıbal

    2015-10-01

    We study the possible existence of gravitational phase transitions from AdS to dS geometries in the context of higher-curvature gravities. We use Lanczos-Gauss-Bonnet (LGB) theory with a positive cosmological constant as a toy model. This theory has two maximally symmetric vacua with positive (dS) and negative (AdS) constant curvature. We show that a phase transition from the AdS vacuum to a dS black hole geometry takes place when the temperature reaches a critical value. The transition is produced by nucleation of bubbles of the new phase that expand afterwards. We claim that this phenomenon is not particular to the model under study, that contains Boulware-Deser instabilities, but shall also be part of generic gravitational theories with higher-curvature terms, where these problems are absent. A salient feature that emerges when a positive cosmological constant is considered is that the temperature in which these bubbles may form is bounded from above. Thermodynamically this property is related to quite an uncommon feature that this system exhibits, namely, the existence of a zeroth-order phase transition.

  3. Conserved charges in timelike warped AdS3 spaces

    NASA Astrophysics Data System (ADS)

    Donnay, L.; Fernández-Melgarejo, J. J.; Giribet, G.; Goya, A.; Lavia, E.

    2015-06-01

    We consider the timelike version of warped anti-de Sitter space (WAdS), which corresponds to the three-dimensional section of the Gödel solution of four-dimensional cosmological Einstein equations. This geometry presents closed timelike curves (CTCs), which are inherited from its four-dimensional embedding. In three dimensions, this type of solution can be supported without matter provided the graviton acquires mass. Here, among the different ways to consistently give mass to the graviton in three dimensions, we consider the parity-even model known as new massive gravity (NMG). In the bulk of timelike WAdS3 space, we introduce defects that, from the three-dimensional point of view, represent spinning massive particlelike objects. For this type of source, we investigate the definition of quasilocal gravitational energy as seen from infinity, far beyond the region where the CTCs appear. We also consider the covariant formalism applied to NMG to compute the mass and the angular momentum of spinning particlelike defects and compare the result with the one obtained by means of the quasilocal stress tensor. We apply these methods to special limits in which the WAdS3 solutions coincide with locally AdS3 and locally AdS2×R spaces. Finally, we make some comments about the asymptotic symmetry algebra of asymptotically WAdS3 spaces in NMG.

  4. Parallel processing of ADS40 images on PC network

    NASA Astrophysics Data System (ADS)

    Qiu, Feng; Duan, Yansong; Zhang, Jianqing

    2009-10-01

    In this paper, we aim to design a parallel processing system based on economic hardware environment to optimize photogrammetric process of Leica ADS40 images considering ideas and methods of parallel computing. We adopt parallel computing PCAM principle to design and implement a test system for parallel processing of ADS40 images. The test system consists of common personal computers and local gigabits network. It can make full use of network computing and storage resources under a economical and practical cost to deal with ADS40 images. Experiment shows that it achieves significant improvement of processing efficiency. Furthermore, the robustness and compatibility of this system is much higher than stand alone computer system because of system's redundancy based on network. In conclusion, parallel processing system based on PC network brings us a much more efficiency solution of ADS40's photogrammetric production.

  5. Influence of coagulation factor x on in vitro and in vivo gene delivery by adenovirus (Ad) 5, Ad35, and chimeric Ad5/Ad35 vectors.

    PubMed

    Greig, Jenny A; Buckley, Suzanne Mk; Waddington, Simon N; Parker, Alan L; Bhella, David; Pink, Rebecca; Rahim, Ahad A; Morita, Takashi; Nicklin, Stuart A; McVey, John H; Baker, Andrew H

    2009-10-01

    The binding of coagulation factor X (FX) to the hexon of adenovirus (Ad) 5 is pivotal for hepatocyte transduction. However, vectors based on Ad35, a subspecies B Ad, are in development for cancer gene therapy, as Ad35 utilizes CD46 (which is upregulated in many cancers) for transduction. We investigated whether interaction of Ad35 with FX influenced vector tropism using Ad5, Ad35, and Ad5/Ad35 chimeras: Ad5/fiber(f)35, Ad5/penton(p)35/f35, and Ad35/f5. Surface plasmon resonance (SPR) revealed that Ad35 and Ad35/f5 bound FX with approximately tenfold lower affinities than Ad5 hexon-containing viruses, and electron cryomicroscopy (cryo-EM) demonstrated a direct Ad35 hexon:FX interaction. The presence of physiological levels of FX significantly inhibited transduction of vectors containing Ad35 fibers (Ad5/f35, Ad5/p35/f35, and Ad35) in CD46-positive cells. Vectors were intravenously administered to CD46 transgenic mice in the presence and absence of FX-binding protein (X-bp), resulting in reduced liver accumulation for all vectors. Moreover, Ad5/f35 and Ad5/p35/f35 efficiently accumulated in the lung, whereas Ad5 demonstrated poor lung targeting. Additionally, X-bp significantly reduced lung genome accumulation for Ad5/f35 and Ad5/p35/f35, whereas Ad35 was significantly enhanced. In summary, vectors based on the full Ad35 serotype will be useful vectors for selective gene transfer via CD46 due to a weaker FX interaction compared to Ad5.

  6. Testing low cost anaerobic digestion (AD) systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the potential for low technology and low cost digesters for small dairies, BARC and researchers from the University of Maryland installed six modified Taiwanese-model field-scale (FS) digesters near the original dairy manure digester. The FS units receive the same post-separated liquid ...

  7. Added Value in Electronic Publications.

    ERIC Educational Resources Information Center

    Bothma, Theo J. D.

    Electronic publications are flooding the market. Some of these publications are created specifically for the electronic environment, but many are conversions of existing material to electronic format. It is not worth the time and effort merely to publish existing material in electronic format if no value is added in the conversion process. The…

  8. Is School Value Added Indicative of Principal Quality?

    ERIC Educational Resources Information Center

    Chiang, Hanley; Lipscomb, Stephen; Gill, Brian

    2016-01-01

    States across the country are developing systems for evaluating school principals on the basis of student achievement growth. A common approach is to hold principals accountable for the value added of their schools--that is, schools' contributions to student achievement growth. In theory, school value added can reflect not only principals'…

  9. Exogenous Variables and Value-Added Assessments: A Fatal Flaw

    ERIC Educational Resources Information Center

    Berliner, David C.

    2014-01-01

    Background: There has been rapid growth in value-added assessment of teachers to meet the widely supported policy goal of identifying the most effective and the most ineffective teachers in a school system. The former group is to be rewarded while the latter group is to be helped or fired for their poor performance. But, value-added approaches to…

  10. Value Added Methods: Moving from Univariate to Multivariate Criteria

    ERIC Educational Resources Information Center

    Newman, David; Newman, Isadore; Ridenour, Carolyn; Morales, Jennifer

    2014-01-01

    The authors describe five value-added methods (VAM) used in school assessment as the backdrop to their main thesis. Then they review the assumptions underlying measurement and evaluation, the foundation of all assessment systems, including value-added. They discuss the traditional criterion variable used in VAM: a standardized test score. Next,…

  11. How Does Value-Added Data Affect Teachers?

    ERIC Educational Resources Information Center

    Jennings, Jennifer L.; Pallas, Aaron M.

    2016-01-01

    Teacher evaluation systems can have high stakes for individual teachers, and it's important to ask how new evaluation models--including value-added measures--serve teachers as they strive to improve their practice. The authors interviewed teachers at a high-performing New York City school about their reactions to their value-added scores and…

  12. Thermodynamics of charged Lovelock: AdS black holes

    NASA Astrophysics Data System (ADS)

    Prasobh, C. B.; Suresh, Jishnu; Kuriakose, V. C.

    2016-04-01

    We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.

  13. An investigation of AdS2 backreaction and holography

    NASA Astrophysics Data System (ADS)

    Engelsöy, Julius; Mertens, Thomas G.; Verlinde, Herman

    2016-07-01

    We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski [1] and develop a 1d effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1d version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.

  14. Superconformal algebras on the boundary of AdS3

    NASA Astrophysics Data System (ADS)

    Rasmussen, Jørgen

    1999-07-01

    Motivated by recent progress on the correspondence between string theory on nti-de Sitter space and conformal field theory, we provide an explicit construction of an infinite dimensional class of superconformal algebras on the boundary of AdS3. These space-time algebras are N extended superconformal algebras of the kind obtainable by hamiltonian reduction of affine SL(2|N/2) current superalgebras for N even, and are induced by the same current superalgebras residing on the world sheet. Thus, such an extended superconformal algebra is generated by N supercurrents and an SL(N/2) current algebra in addition to a U(1) current algebra. The results are obtained within the framework of free field realizations.

  15. Systematics of Coupling Flows in AdS Backgrounds

    SciTech Connect

    Goldberger, Walter D.; Rothstein, Ira Z.

    2003-03-18

    We give an effective field theory derivation, based on the running of Planck brane gauge correlators, of the large logarithms that arise in the predictions for low energy gauge couplings in compactified AdS}_5 backgrounds, including the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast to the case of charged scalars coupled to Abelian gauge fields that has been considered previously in the literature, the one-loop corrections are not dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge field loops, the amplitudes can be reorganized into a leading logarithmic contribution that is identical to the running in 4D non-Abelian gauge theory, and a term which is not logarithmically enhanced and is analogous to a two-loop effect in 4D. In a warped GUT model broken by the Higgs mechanism in the bulk,we show that the matching scale that appears in the large logarithms induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV scale in the logarithmic contributions of scalars, which is simply the bulk mass m. Our results are summarized in a set of simple rules that can be applied to compute the leading logarithmic predictions for coupling constant relations within a given warped GUT model. We present results for both bulk Higgs and boundary breaking of the GUT gauge

  16. Holography beyond conformal invariance and AdS isometry?

    SciTech Connect

    Barvinsky, A. O.

    2015-03-15

    We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O(N{sup 0}) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the “double-trace” deformation of the boundary theory, which is responsible in the case of large-N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.

  17. ADS: The Next Generation Search Platform

    NASA Astrophysics Data System (ADS)

    Accomazzi, A.; Kurtz, M. J.; Henneken, E. A.; Chyla, R.; Luker, J.; Grant, C. S.; Thompson, D. M.; Holachek, A.; Dave, R.; Murray, S. S.

    2015-04-01

    Four years after the last LISA meeting, the NASA Astrophysics Data System (ADS) finds itself in the middle of major changes to the infrastructure and contents of its database. In this paper we highlight a number of features of great importance to librarians and discuss the additional functionality that we are currently developing. Our citation coverage has doubled since 2010 and now consists of over 10 million citations. We are normalizing the affiliation information in our records and we have started collecting and linking funding sources with papers in our system. At the same time, we are undergoing major technology changes in the ADS platform. We have rolled out and are now enhancing a new high-performance search engine capable of performing full-text as well as metadata searches using an intuitive query language. We are currently able to index acknowledgments, affiliations, citations, and funding sources. While this effort is still ongoing, some of its benefits are already available through the ADS Labs user interface and API at http://adslabs.org/adsabs/.

  18. Noncommutative q -photon-added coherent states

    NASA Astrophysics Data System (ADS)

    Dey, Sanjib; Hussin, Véronique

    2016-05-01

    We construct the photon-added coherent states of a noncommutative harmonic oscillator associated to a q -deformed oscillator algebra. Various nonclassical properties of the corresponding system are explored, first, by studying two different types of higher-order quadrature squeezing, namely, the Hillery type and the Hong-Mandel type, and second, by testing the sub-Poissonian nature of photon statistics in higher order with the help of the correlation function and the Mandel parameter. Also, we compare the behavior of different types of quadrature and photon number squeezing of our system with those of the ordinary harmonic oscillator by considering the same set of parameters.

  19. - criticality of AdS black hole in the Einstein-Maxwell-power-Yang-Mills gravity

    NASA Astrophysics Data System (ADS)

    Zhang, Ming; Yang, Zhan-Ying; Zou, De-Cheng; Xu, Wei; Yue, Rui-Hong

    2015-02-01

    We study the - critical behaivor of N-dimensional AdS black holes in Einstein-Maxwell-power-Yang-Mills gravity. Our results show the existence of the Van der Waals like small-large black hole phase transitions when taking some special values of charges of the Maxwell and Yang-Mills fields. Further to calculate the critical exponents of the black holes at the critical point, we find that they are the same as those in the Van der Waals liquid-gas system.

  20. Exact results for the low energy AdS 4 × 3 string theory

    NASA Astrophysics Data System (ADS)

    Fabbri, Alessandro; Fioravanti, Davide; Piscaglia, Simone; Tateo, Roberto

    2013-11-01

    We derive the Thermodynamic Bethe Ansatz equations for the relativistic sigma model describing the AdS 4 × 3 string II A theory at strong coupling (i.e. in the Alday-Maldacena decoupling limit). The corresponding Y -system involves an infinite number of Y functions and is of a new type, although it shares a peculiar feature with the Y -system for AdS 4 × 3. A truncation of the equations at level p and a further generalisation to generic rank N allow us an alternative description of the theory as the N =4, p = ∞ representative in an infinite family of models corresponding to the conformal cosets ( N -1) p × U(1), perturbed by a relevant composite field ϕ ( N,p) = ϕ[( N -1) p ] × ϕ [U(1)] that couples the two independent conformal field theories. The calculation of the ultraviolet central charge confirms the conjecture by Basso and Rej and the conformal dimension of the perturbing operator, at every N and p, is obtained using the Y-system periodicity. The conformal dimension of ϕ[( N -1) p ] matches that of the field identified by Fendley while discussing integrability issues for the purely bosonic N -1 sigma model.

  1. Scattering States in AdS/CFT

    SciTech Connect

    Fitzpatrick, A.Liam; Kaplan, Jared; /SLAC

    2012-02-14

    We show that suitably regulated multi-trace primary states in large N CFTs behave like 'in' and 'out' scattering states in the flat-space limit of AdS. Their transition matrix elements approach the exact scattering amplitudes for the bulk theory, providing a natural CFT definition of the flat space S-Matrix. We study corrections resulting from the AdS curvature and particle propagation far from the center of AdS, and show that AdS simply provides an IR regulator that disappears in the flat space limit.

  2. Magnetic mass in 4D AdS gravity

    NASA Astrophysics Data System (ADS)

    Araneda, René; Aros, Rodrigo; Miskovic, Olivera; Olea, Rodrigo

    2016-04-01

    We provide a fully covariant expression for the diffeomorphic charge in four-dimensional anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to the action. The couplings of these topological invariants are such that the Weyl tensor and its dual appear in the on-shell variation of the action and such that the action is stationary for asymptotic (anti-)self-dual solutions in the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the self-duality condition is global, both the action and the total charge are identically vanishing. Therefore, for such configurations, the magnetic mass equals the Ashtekhar-Magnon-Das definition.

  3. Short communication: Use of a portable, automated, open-circuit gas quantification system and the sulfur hexafluoride tracer technique for measuring enteric methane emissions in Holstein cows fed ad libitum or restricted.

    PubMed

    Dorich, C D; Varner, R K; Pereira, A B D; Martineau, R; Soder, K J; Brito, A F

    2015-04-01

    The objective of this study was to measure enteric CH4 emissions using a new portable automated open-circuit gas quantification system (GQS) and the sulfur hexafluoride tracer technique (SF6) in midlactation Holstein cows housed in a tiestall barn. Sixteen cows averaging 176 ± 34 d in milk, 40.7 ± 6.1 kg of milk yield, and 685 ± 49 kg of body weight were randomly assigned to 1 out of 2 treatments according to a crossover design. Treatments were (1) ad libitum (adjusted daily to yield 10% orts) and (2) restricted feed intake [set to restrict feed by 10% of baseline dry matter intake (DMI)]. Each experimental period lasted 22d, with 14 d for treatment adaptation and 8d for data and sample collection. A common diet was fed to the cows as a total mixed ration and contained 40.4% corn silage, 11.2% grass-legume haylage, and 48.4% concentrate on a dry matter basis. Spot 5-min measurements using the GQS were taken twice daily with a 12-h interval between sampling and sampling times advanced 2h daily to account for diurnal variation in CH4 emissions. Canisters for the SF6 method were sampled twice daily before milking with 4 local background gas canisters inside the barn analyzed for background gas concentrations. Enteric CH4 emissions were not affected by treatments and averaged 472 and 458 g/d (standard error of the mean = 18 g/d) for ad libitum and restricted intake treatments, respectively (data not shown). The GQS appears to be a reliable method because of the relatively low coefficients of variation (ranging from 14.1 to 22.4%) for CH4 emissions and a moderate relationship (coefficient of determination = 0.42) between CH4 emissions and DMI. The SF6 resulted in large coefficients of variation (ranging from 16.0 to 111%) for CH4 emissions and a poor relationship (coefficient of determination = 0.17) between CH4 emissions and DMI, likely because of limited barn ventilation and high background gas concentration. Research with improved barn ventilation systems or

  4. Short communication: Use of a portable, automated, open-circuit gas quantification system and the sulfur hexafluoride tracer technique for measuring enteric methane emissions in Holstein cows fed ad libitum or restricted.

    PubMed

    Dorich, C D; Varner, R K; Pereira, A B D; Martineau, R; Soder, K J; Brito, A F

    2015-04-01

    The objective of this study was to measure enteric CH4 emissions using a new portable automated open-circuit gas quantification system (GQS) and the sulfur hexafluoride tracer technique (SF6) in midlactation Holstein cows housed in a tiestall barn. Sixteen cows averaging 176 ± 34 d in milk, 40.7 ± 6.1 kg of milk yield, and 685 ± 49 kg of body weight were randomly assigned to 1 out of 2 treatments according to a crossover design. Treatments were (1) ad libitum (adjusted daily to yield 10% orts) and (2) restricted feed intake [set to restrict feed by 10% of baseline dry matter intake (DMI)]. Each experimental period lasted 22d, with 14 d for treatment adaptation and 8d for data and sample collection. A common diet was fed to the cows as a total mixed ration and contained 40.4% corn silage, 11.2% grass-legume haylage, and 48.4% concentrate on a dry matter basis. Spot 5-min measurements using the GQS were taken twice daily with a 12-h interval between sampling and sampling times advanced 2h daily to account for diurnal variation in CH4 emissions. Canisters for the SF6 method were sampled twice daily before milking with 4 local background gas canisters inside the barn analyzed for background gas concentrations. Enteric CH4 emissions were not affected by treatments and averaged 472 and 458 g/d (standard error of the mean = 18 g/d) for ad libitum and restricted intake treatments, respectively (data not shown). The GQS appears to be a reliable method because of the relatively low coefficients of variation (ranging from 14.1 to 22.4%) for CH4 emissions and a moderate relationship (coefficient of determination = 0.42) between CH4 emissions and DMI. The SF6 resulted in large coefficients of variation (ranging from 16.0 to 111%) for CH4 emissions and a poor relationship (coefficient of determination = 0.17) between CH4 emissions and DMI, likely because of limited barn ventilation and high background gas concentration. Research with improved barn ventilation systems or

  5. Safety features of subcritical fluid fueled systems

    NASA Astrophysics Data System (ADS)

    Bell, Charles R.

    1995-09-01

    Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible.

  6. Transmutation of Long-Lived Nuclear Wastes

    NASA Astrophysics Data System (ADS)

    Oigawa, Hiroyuki

    JAEA is conducting research and development on an Accelerator Driven System (ADS), aiming at reduction of burden for high-level radioactive wastes. To tackle technical challenges on ADS, JAEA is planning to build the Transmutation Experimental Facility as the Phase-2 program of J-PARC. Moreover, JAEA is considering the collaboration with the MYRRHA project proposed by Belgian Nuclear Research Center.

  7. AdS black holes from duality in gauged supergravity

    NASA Astrophysics Data System (ADS)

    Halmagyi, Nick; Vanel, Thomas

    2014-04-01

    We study and utilize duality transformations in a particular STU-model of four dimensional gauged supergravity. This model is a truncation of the de Wit-Nicolai =8 theory and as such has a lift to eleven-dimensional supergravity on the seven-sphere. Our duality group is U(1)3 and while it can be applied to any solution of this theory, we consider known asymptotically AdS4, supersymmetric black holes and focus on duality transformations which preserve supersymmetry. For static black holes we generalize the supersymmetric solutions of Cacciatori and Klemm from three magnetic charges to include two additional electric charges and argue that this is co-dimension one in the full space of supersymmetric static black holes in the STU-model. These new static black holes have nontrivial profiles for axions. For rotating black holes, we generalize the known two-parameter supersymmetric solution to include an additional parameter. When lifted to M-theory, these black holes correspond to the near horizon geometry of a stack of BPS rotating M2-branes, spinning on an S 7 which is fibered non-trivially over a Riemann surface.

  8. Stability of charged global AdS4 spacetimes

    NASA Astrophysics Data System (ADS)

    Arias, Raúl; Mas, Javier; Serantes, Alexandre

    2016-09-01

    We study linear and nonlinear stability of asymptotically AdS4 solutions in Einstein-Maxwell-scalar theory. After summarizing the set of static solutions we first examine thermodynamical stability in the grand canonical ensemble and the phase transitions that occur among them. In the second part of the paper we focus on nonlinear stability in the microcanonical ensemble by evolving radial perturbations numerically. We find hints of an instability corner for vanishingly small perturbations of the same kind as the ones present in the uncharged case. Collapses are avoided, instead, if the charge and mass of the perturbations come to close the line of solitons. Finally we examine the soliton solutions. The linear spectrum of normal modes is not resonant and instability turns on at extrema of the mass curve. Linear stability extends to nonlinear stability up to some threshold for the amplitude of the perturbation. Beyond that, the soliton is destroyed and collapses to a hairy black hole. The relative width of this stability band scales down with the charge Q, and does not survive the blow up limit to a planar geometry.

  9. Null-polygonal minimal surfaces in AdS4 from perturbed W minimal models

    NASA Astrophysics Data System (ADS)

    Hatsuda, Yasuyuki; Ito, Katsushi; Satoh, Yuji

    2013-02-01

    We study the null-polygonal minimal surfaces in AdS4, which correspond to the gluon scattering amplitudes/Wilson loops in {N} = 4 super Yang-Mills theory at strong coupling. The area of the minimal surfaces with n cusps is characterized by the thermodynamic Bethe ansatz (TBA) integral equations or the Y-system of the homogeneous sine-Gordon model, which is regarded as the SU( n - 4)4 /U(1) n-5 generalized parafermion theory perturbed by the weight-zero adjoint operators. Based on the relation to the TBA systems of the perturbed W minimal models, we solve the TBA equations by using the conformal perturbation theory, and obtain the analytic expansion of the remainder function around the UV/regular-polygonal limit for n = 6 and 7. We compare the rescaled remainder function for n = 6 with the two-loop one, to observe that they are close to each other similarly to the AdS3 case.

  10. Adding control to arbitrary unknown quantum operations

    PubMed Central

    Zhou, Xiao-Qi; Ralph, Timothy C.; Kalasuwan, Pruet; Zhang, Mian; Peruzzo, Alberto; Lanyon, Benjamin P.; O'Brien, Jeremy L.

    2011-01-01

    Although quantum computers promise significant advantages, the complexity of quantum algorithms remains a major technological obstacle. We have developed and demonstrated an architecture-independent technique that simplifies adding control qubits to arbitrary quantum operations—a requirement in many quantum algorithms, simulations and metrology. The technique, which is independent of how the operation is done, does not require knowledge of what the operation is, and largely separates the problems of how to implement a quantum operation in the laboratory and how to add a control. Here, we demonstrate an entanglement-based version in a photonic system, realizing a range of different two-qubit gates with high fidelity. PMID:21811242

  11. Condom ads slated for TV.

    PubMed

    1987-02-20

    3 CBS-owned television stations and NBC's New York television station announced yesterday that they would begin accepting condom advertising. In addition, the ABC network announced it will begin running a 30-second public service message with Dr. C. Everett Koop, the US surgeon general, saying that condoms are the best protection against sexual transmission of AIDS. CBS said it will allow the 4 television stations and 18 radio stations it owns to accept condom advertising based on the attitudes of the local viewing or listening community. WCBS-TV in New York, WCAU-TV in Philadelphia and KCBS-TV in Los Angeles said they would accept such ads. CBS also owns a television station in Chicago. WCAU will air condom ads after 11 p.m. only, beginning probably next week, said Paul Webb, a station spokesman. "We recognize the legitimate sensitivities of some members of the community in regard to this issue," said Steve Cohen, the WCAU general manager. "However, it is the judgment of this station that the importance of providing information about the AIDS epidemic and means of prevention is an overriding consideration." NBC's New York television station, WNBC, announced that it will accept condom advertising and public service announcements. PMID:12269166

  12. Holographic fermionic spectrum from Born-Infeld AdS black hole

    NASA Astrophysics Data System (ADS)

    Wu, Jian-Pin

    2016-07-01

    In this letter, we systematically explore the holographic (non-)relativistic fermionic spectrum without/with dipole coupling dual to Born-Infeld anti-de Sitter (BI-AdS) black hole. For the relativistic fermionic fixed point, this holographic fermionic system exhibits non-Fermi liquid behavior. Also, with the increase of BI parameter γ, the non-Fermi liquid becomes even "more non-Fermi". When the dipole coupling term is included, we find that the BI term makes it a lot tougher to form the gap. While for the non-relativistic fermionic system with large dipole coupling in BI-AdS background, with the increase of BI parameter, the gap comes into being again.

  13. Dyonic AdS 4 black hole entropy and attractors via entropy function

    NASA Astrophysics Data System (ADS)

    Goulart, Prieslei

    2016-09-01

    Using the Sen's entropy function formalism, we compute the entropy for the extremal dyonic black hole solutions of theories in the presence of dilaton field coupled to the field strength and a dilaton potential. We solve the attractor equations analytically and determine the near horizon metric, the value of the scalar fields and the electric field on the horizon, and consequently the entropy of these black holes. The attractor mechanism plays a very important role for these systems, and after studying the simplest systems involving dilaton fields, we propose a general solution for the value of the scalar field on the horizon, which allows us to solve the attractor equations for gauged supergravity theories in AdS 4 spaces. In particular, we derive an expression for the dyonic black hole entropy for the {N}=8 gauged supergravity in 4 dimensions which does not contain explicitly the gauge parameter of the potential.

  14. Dyonic AdS 4 black hole entropy and attractors via entropy function

    NASA Astrophysics Data System (ADS)

    Goulart, Prieslei

    2016-09-01

    Using the Sen's entropy function formalism, we compute the entropy for the extremal dyonic black hole solutions of theories in the presence of dilaton field coupled to the field strength and a dilaton potential. We solve the attractor equations analytically and determine the near horizon metric, the value of the scalar fields and the electric field on the horizon, and consequently the entropy of these black holes. The attractor mechanism plays a very important role for these systems, and after studying the simplest systems involving dilaton fields, we propose a general solution for the value of the scalar field on the horizon, which allows us to solve the attractor equations for gauged supergravity theories in AdS 4 spaces. In particular, we derive an expression for the dyonic black hole entropy for the N=8 gauged supergravity in 4 dimensions which does not contain explicitly the gauge parameter of the potential.

  15. Quantum compositeness of gravity: black holes, AdS and inflation

    SciTech Connect

    Dvali, Gia; Gomez, Cesar E-mail: cesar.gomez@uam.es

    2014-01-01

    Gravitational backgrounds, such as black holes, AdS, de Sitter and inflationary universes, should be viewed as composite of N soft constituent gravitons. It then follows that such systems are close to quantum criticality of graviton Bose-gas to Bose-liquid transition. Generic properties of the ordinary metric description, including geodesic motion or particle-creation in the background metric, emerge as the large-N limit of quantum scattering of constituent longitudinal gravitons. We show that this picture correctly accounts for physics of large and small black holes in AdS, as well as reproduces well-known inflationary predictions for cosmological parameters. However, it anticipates new effects not captured by the standard semi-classical treatment. In particular, we predict observable corrections that are sensitive to the inflationary history way beyond last 60 e-foldings. We derive an absolute upper bound on the number of e-foldings, beyond which neither de Sitter nor inflationary Universe can be approximated by a semi-classical metric. However, they could in principle persist in a new type of quantum eternity state. We discuss implications of this phenomenon for the cosmological constant problem.

  16. Quantum compositeness of gravity: black holes, AdS and inflation

    SciTech Connect

    Dvali, Gia; Gomez, Cesar

    2014-01-14

    Gravitational backgrounds, such as black holes, AdS, de Sitter and inflationary universes, should be viewed as composite of N soft constituent gravitons. It then follows that such systems are close to quantum criticality of graviton Bose-gas to Bose-liquid transition. Generic properties of the ordinary metric description, including geodesic motion or particle-creation in the background metric, emerge as the large-N limit of quantum scattering of constituent longitudinal gravitons. We show that this picture correctly accounts for physics of large and small black holes in AdS, as well as reproduces well-known inflationary predictions for cosmological parameters. However, it anticipates new effects not captured by the standard semi-classical treatment. In particular, we predict observable corrections that are sensitive to the inflationary history way beyond last 60 e-foldings. We derive an absolute upper bound on the number of e-foldings, beyond which neither de Sitter nor inflationary Universe can be approximated by a semi-classical metric. However, they could in principle persist in a new type of quantum eternity state. We discuss implications of this phenomenon for the cosmological constant problem.

  17. AdS5 solutions from M5-branes on Riemann surface and D6-branes sources

    NASA Astrophysics Data System (ADS)

    Bah, Ibrahima

    2015-09-01

    We describe the gravity duals of four-dimensional N=1 superconformal field theories obtained by wrapping M5-branes on a punctured Riemann surface. The internal geometry, normal to the AdS 5 factor, generically preserves two U(1)s, with generators ( J +, J -), that are fibered over the Riemann surface. The metric is governed by a single potential that satisfies a version of the Monge-Ampère equation. The spectrum of N=1 punctures is given by the set of supersymmetric sources of the potential that are localized on the Riemann surface and lead to regular metrics near a puncture. We use this system to study a class of punctures where the geometry near the sources corresponds to M-theory description of D6-branes. These carry a natural ( p, q) label associated to the circle dual to the killing vector pJ + + qJ - which shrinks near the source. In the generic case the world volume of the D6-branes is AdS 5 × S 2 and they locally preserve N=2 supersymmetry. When p = - q, the shrinking circle is dual to a flavor U(1). The metric in this case is non-degenerate only when there are co-dimension one sources obtained by smearing M5-branes that wrap the AdS 5 factor and the circle dual the superconformal R-symmetry. The D6-branes are extended along the AdS 5 and on cups that end on the co-dimension one branes. In the special case when the shrinking circle is dual to the R-symmetry, the D6-branes are extended along the AdS 5 and wrap an auxiliary Riemann surface with an arbitrary genus. When the Riemann surface is compact with constant curvature, the system is governed by a Monge-Ampère equation.

  18. The Physics of transmutation systems : system capabilities and performances.

    SciTech Connect

    Finck, P. J.

    2002-08-21

    This document is complementary to a document produced by Prof. Salvatores on ''The Physics of Transmutation in Critical or Subcritical Reactors and the Impact on the Fuel Cycle''. In that document, Salvatores describes the fundamental of transmutation, through basic physics properties and general parametric studies. In the present document we try to go one step further towards practical implementation (while recognizing that the practical issues such as technology development and demonstration, and economics, can only be mentioned in a very superficial manner). Section 1 briefly overviews the possible objectives of transmutation systems, and links these different objectives to possible technological paths. It also describes the overall constraints which have to be considered when developing and implementing transmutation systems. In section 2 we briefly overview the technological constraints which need to be accounted for when designing transmutation systems. In section 3 we attempt to provide a simplified classification of transmutation systems in order to clarify later comparisons. It compares heterogeneous and homogeneous recycle strategies, and single and multi-tier systems. Section 4 presents case analyses for assessing the transmutation performance of various individual systems, starting with LWR's (1. generic results; 2. multirecycle of plutonium; 3. an alternative: transmutation based on a Thorium fuel cycle), followed by Gas-Cooled Reactors (with an emphasis on the ''deep burn'' approach), and followed by Fast Reactors and Accelerator Driven systems (1. generic results; 2. homogeneous recycle of transuranics; 3. practical limit between Fast Reactors and Accelerator Driven Systems) Section 5 summarizes recent results on integrated system performances. It focuses first on interface effects between the two elements of a dual tier system, and then summarizes the major lessons learned from recent global physics studies.

  19. Apache Drill: Interactive Ad-Hoc Analysis at Scale.

    PubMed

    Hausenblas, Michael; Nadeau, Jacques

    2013-06-01

    Apache Drill is a distributed system for interactive ad-hoc analysis of large-scale datasets. Designed to handle up to petabytes of data spread across thousands of servers, the goal of Drill is to respond to ad-hoc queries in a low-latency manner. In this article, we introduce Drill's architecture, discuss its extensibility points, and put it into the context of the emerging offerings in the interactive analytics realm.

  20. The New York Times ad.

    PubMed

    Hunt, M E; Kissling, F

    1993-01-01

    Feminization of patriarchal institutions is necessary in order to eliminate the exclusivity and mutuality of hierarchical, gender, class, and race stratification. The aim of this paper is to explain the history and activities surrounding the New York Times ad on Sunday, October 7, 1984 (the Catholic Statement on Pluralism and Abortion signed by Barbara Ferraro and Patricia Hussey of the Sisters of Note Dame de Namur, Rose Dominic Trapasso of the Maryknoll Sisters, and 67 other signers). The significance of this ad for Roman Catholic feminists and suggestions for new models of relationships between feminists is given. The Statement was written by Daniel Maguire and Frances Kissling and reviewed by 20 Roman Catholic ethicists. A sponsoring committee of early signers sought other support. Catholics for a Free Choice sponsored the funding for circulation of the Statement among professional societies, but not necessarily canonical communities. Publication of the entire statement in the Times was at the height of the presidential campaign. Conservative Bishops Bernard Law of Boston and John O'Connor of Boston publicly denounced Ferraro's position. The first institutional church response came on November 14, 1984, and stated that the Statement was personal opinion and contradictory to clear and constant church teachings about abortion. On November 30, 1984, Cardinal Jean Jerome Hamer of the Congregation for Religious and Secular Institutes responded to most presidents of canonical communities to request a public retraction from signers under threat of dismissal. The issue was obedience to the church. Several members of the canonical community and priests published retractions; negotiations with the Vatican began. Freedom of conscience and empowerment of canonical communities, as agents of their own lives, were given as reasons for the challenge to paternalism. The response was that women were subject to obedience within their communities and had taken public vows and were

  1. Myths & Facts about Value-Added Analysis

    ERIC Educational Resources Information Center

    TNTP, 2011

    2011-01-01

    This paper presents myths as well as facts about value-added analysis. These myths include: (1) "Value-added isn't fair to teachers who work in high-need schools, where students tend to lag far behind academically"; (2) "Value-added scores are too volatile from year-to-year to be trusted"; (3) "There's no research behind value-added"; (4) "Using…

  2. ATW system impact on high-level waste

    SciTech Connect

    Arthur, E.D.

    1992-12-01

    This report discusses the Accelerator Transmutation of Waste (ATW) concept which aims at destruction of key long-lived radionuclides in high-level nuclear waste (HLW), both fission products and actinides. This focus makes it different from most other transmutation concepts which concentrate primarily on actinide burning. The ATW system uses an accelerator-driven, sub-critical assembly to create an intense thermal neutron environment for radionuclide transmutation. This feature allows rapid transmutation under low-inventory system conditions, which in turn, has a direct impact on the size of chemical separations and materials handling components of the system. Inventories in ATW are factors of eight to thirty times smaller than reactor systems of equivalent thermal power. Chemical separations systems are relatively small in scale and can be optimized to achieve high decontamination factors and minimized waste streams. The low-inventory feature also directly impacts material amounts remaining in the system at its end of life. In addition to its low-inventory operation, the accelerator-driven neutron source features of ATW are key to providing a sufficient level of neutrons to allow transmutation of long-lived fission products.

  3. All-loop Bethe ansatz equations for AdS3/CFT2

    NASA Astrophysics Data System (ADS)

    Borsato, Riccardo; Sax, Olof Ohlsson; Sfondrini, Alessandro

    2013-04-01

    Using the S-matrix for the {d}{{( {2, 1; α } )}^2} symmetric spin-chain of AdS3/CFT2, we propose a new set of all-loop Bethe equations for the system. These equations differ from the ones previously found in the literature by the choice of relative grading between the two copies of the {d}( {2, 1; α } ) superalgebra, and involve four undetermined scalar factors that play the role of dressing phases. Imposing crossing symmetry and comparing with the near-BMN form of the S-matrix found in the literature, we find several novel features. In particular, the scalar factors must differ from the Beisert-Eden-Staudacher phase, and should couple nodes of different masses to each other. In the semiclassical limit the phases are given by a suitable generalization of Arutyunov-Frolov-Staudacher phase.

  4. Charge loss (or the lack thereof) for AdS black holes

    NASA Astrophysics Data System (ADS)

    Ong, Yen Chin; Chen, Pisin

    2014-06-01

    The evolution of evaporating charged black holes is complicated to model in general, but is nevertheless important since the hints to the Information Loss Paradox and its recent firewall incarnation may lie in understanding more generic geometries than that of Schwarzschild spacetime. Fortunately, for sufficiently large asymptotically flat Reissner-Nordström black holes, the evaporation process can be modeled via a system of coupled linear ordinary differential equations, with charge loss rate governed by Schwinger pair-production process. The same model can be generalized to study the evaporation of AdS Reissner-Nordström black holes with flat horizon. It was recently found that such black holes always evolve towards extremality since charge loss is inefficient. This property is completely opposite to the asymptotically flat case in which the black hole eventually loses its charges and tends towards Schwarzschild limit. We clarify the underlying reason for this different behavior.

  5. Minimal surfaces in q-deformed AdS5xS5

    NASA Astrophysics Data System (ADS)

    Kameyama, Takashi

    2016-01-01

    We study minimal surfaces in q-deformed AdS5×S5. For this purpose, it is convenient to introduce a coordinate system which describes the spacetime only inside the singularity surface and treat the singularity surface as the holographic screen. In particular, we consider minimal surfaces whose boundary shapes are 1) a straight line and 2) a circle. In the q → 1 limit, the solutions correspond to a 1/2 BPS straight line Wilson loop and a 1/2 BPS circular one, respectively. A remarkable point is that the classical Euclidean actions have no linear divergence unlike the original ones. This finiteness indicates that the q-deformation may be regarded as a UV regularization.

  6. Thermodynamic volumes for AdS-Taub-NUT and AdS-Taub-Bolt

    NASA Astrophysics Data System (ADS)

    Johnson, Clifford V.

    2014-12-01

    In theories of semi-classical quantum gravity where the cosmological constant is considered a thermodynamic variable, the gravitational mass of a black hole has been shown to correspond to the enthalpy of the thermodynamic system, rather than the energy. We propose that this should be extended to all spacetime solutions, and consider the meaning of this extension of gravitational thermodynamics for the Taub-NUT and Taub-Bolt geometries in four dimensional locally anti-de Sitter spacetime. We present formulae for their thermodynamic volumes. Surprisingly, Taub-NUT has negative volume, for which there is a natural dynamical explanation in terms of the process of formation of the spacetime. A special case corresponds to pure AdS4 with an S3 slicing. The same dynamical setting can explain the negative entropy known to exist for these solutions for a range of parameters.

  7. Condom ads promote illicit sex.

    PubMed

    Kippley, J F

    1994-01-01

    Written in 1987, this opinion was republished in the wake of US President Bill Clinton's AIDS prevention media campaign promoting condom use which began January 1994, targeted at young adults aged 18-25. The author staunchly opposes condom use even though he admits that people do not consider abstinence from sex to be a serious option for the prevention of HIV/STD infection. He believes that there is no moral use of sex with a condom and that condoms have always been a sign of immorality, be it prostitution, adultery, fornication, or marital contraception. Likewise, the author laments the success enjoyed by Planned Parenthood in achieving the social acceptance of marital contraception and sex outside of marriage. The complete social acceptance of homosexual activity, however, remains to be achieved. Magazines, newspapers, and television receive income in exchange for publishing or airing advertisements. Finding offensive advertisements which promote the use of condoms against HIV infection, the author recommends writing letters of complaint to the responsible media sources. If the television stations or publications in question continue to advertise condoms to the public, stop watching them or end one's subscriptions to the particular printed media. Such action taken collectively among many individuals will reduce product sales and income, and potentially sway corporate policy against condom ads. PMID:12345946

  8. Condom ads promote illicit sex.

    PubMed

    Kippley, J F

    1994-01-01

    Written in 1987, this opinion was republished in the wake of US President Bill Clinton's AIDS prevention media campaign promoting condom use which began January 1994, targeted at young adults aged 18-25. The author staunchly opposes condom use even though he admits that people do not consider abstinence from sex to be a serious option for the prevention of HIV/STD infection. He believes that there is no moral use of sex with a condom and that condoms have always been a sign of immorality, be it prostitution, adultery, fornication, or marital contraception. Likewise, the author laments the success enjoyed by Planned Parenthood in achieving the social acceptance of marital contraception and sex outside of marriage. The complete social acceptance of homosexual activity, however, remains to be achieved. Magazines, newspapers, and television receive income in exchange for publishing or airing advertisements. Finding offensive advertisements which promote the use of condoms against HIV infection, the author recommends writing letters of complaint to the responsible media sources. If the television stations or publications in question continue to advertise condoms to the public, stop watching them or end one's subscriptions to the particular printed media. Such action taken collectively among many individuals will reduce product sales and income, and potentially sway corporate policy against condom ads.

  9. 27 CFR 19.456 - Adding denaturants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Adding denaturants. 19.456... Denaturation § 19.456 Adding denaturants. Denaturants and spirits shall be mixed in packages, tanks, or bulk... proprietor shall submit a flow diagram of the intended process or method of adding denaturants. (Sec....

  10. 16 CFR 460.18 - Insulation ads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Insulation ads. 460.18 Section 460.18 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation...

  11. 16 CFR 460.18 - Insulation ads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Insulation ads. 460.18 Section 460.18 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation...

  12. 16 CFR 460.18 - Insulation ads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Insulation ads. 460.18 Section 460.18 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation...

  13. 16 CFR 460.18 - Insulation ads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Insulation ads. 460.18 Section 460.18 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation...

  14. 16 CFR 460.18 - Insulation ads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Insulation ads. 460.18 Section 460.18 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation...

  15. New Features in the ADS Abstract Service

    NASA Technical Reports Server (NTRS)

    Eichhorn, Guenther; Accomazzi, Alberto; Grant, Carolyn S.; Kurtz, Michael J.; Henneken, Edwin A.; Thompson, Donna M.; Murray, Stephen S.

    2005-01-01

    The NASA-ADS Abstract Service provides a sophisticated search capability for the literature in Astronomy, Planetary Sciences, Physics/Geophysics, and Space Instrumentation. The ADS is funded by NASA and access to the ADS services is free to anybody world-wide without restrictions. It allows the user to search the literature by author, title, and abstract text.

  16. Value Added and Other Related Matters.

    ERIC Educational Resources Information Center

    Whitla, Dean K.

    The term "value added" refers to the assessment of the amount of learning that takes place during the college years. Two experiments, Value Added I and Value Added II, attempted to measure college students' attainment of eight liberal education objectives: (1) writing ability; (2) analytical ability; (3) sensitivity to ethics, morals, and values;…

  17. ADS 2.0: New Architecture, API and Services

    NASA Astrophysics Data System (ADS)

    Chyla, R.; Accomazzi, A.; Holachek, A.; Grant, C. S.; Elliott, J.; Henneken, E. A.; Thompson, D. M.; Kurtz, M. J.; Murray, S. S.; Sudilovsky, V.

    2015-09-01

    The ADS platform is undergoing the biggest rewrite of its 20-year history. While several components have been added to its architecture over the past couple of years, this talk will concentrate on the underpinnings of ADS's search layer and its API. To illustrate the design of the components in the new system, we will show how the new ADS user interface is built exclusively on top of the API using RESTful web services. Taking one step further, we will discuss how we plan to expose the treasure trove of information hosted by ADS (10 million records and fulltext for much of the Astronomy and Physics refereed literature) to partners interested in using this API. This will provide you (and your intelligent applications) with access to ADS's underlying data to enable the extraction of new knowledge and the ingestion of these results back into the ADS. Using this framework, researchers could run controlled experiments with content extraction, machine learning, natural language processing, etc. In this talk, we will discuss what is already implemented, what will be available soon, and where we are going next.

  18. High energy QCD from Planckian scattering in AdS space and the Froissart bound

    SciTech Connect

    Kang, Kyungsik; Nastase, Horatiu

    2005-11-15

    We reanalyze high-energy QCD scattering regimes from scattering in cutoff AdS space via gravity-gauge dualities (a la Polchinski-Strassler). We look at 't Hooft scattering, Regge behavior, and black hole creation in AdS space. Black hole creation in the gravity dual is analyzed via gravitational shockwave collisions. We prove the saturation of the QCD Froissart unitarity bound, corresponding to the creation of black holes of AdS size, as suggested by Giddings.

  19. Measuring Added Value in Schools.

    ERIC Educational Resources Information Center

    McPherson, Andrew

    1993-01-01

    The measurement of the performance of schools is complicated by the need to adjust for differences in input mixes. Schools may have a differential effect on the performance of different types of pupils. Rather than a single performance indicator, a system of indicators is needed. Characteristics of a good indicator system are identified. (KDP)

  20. Interacting shells in AdS spacetime and chaos

    NASA Astrophysics Data System (ADS)

    Brito, Richard; Cardoso, Vitor; Rocha, Jorge V.

    2016-07-01

    We study the simplest two-body problem in asymptotically anti-de Sitter spacetime: two, infinitely thin, concentric spherical shells of matter. We include only gravitational interaction between the two shells, but we show that the dynamics of this system is highly nontrivial. We observe prompt collapse to a black hole, delayed collapse and even perpetual oscillatory motion, depending on the initial location of the shells (or their energy content). The system exhibits critical behavior, and we show strong hints that it is also chaotic.

  1. Quantum statistical relation for black holes in nonlinear electrodynamics coupled to Einstein-Gauss-Bonnet AdS gravity

    SciTech Connect

    Miskovic, Olivera; Olea, Rodrigo

    2011-03-15

    We consider curvature-squared corrections to Einstein-Hilbert gravity action in the form of a Gauss-Bonnet term in D>4 dimensions. In this theory, we study the thermodynamics of charged static black holes with anti-de Sitter (AdS) asymptotics, and whose electric field is described by nonlinear electrodynamics. These objects have received considerable attention in recent literature on gravity/gauge dualities. It is well-known that, within the framework of anti-de Sitter/conformal field theory (AdS/CFT) correspondence, there exists a nonvanishing Casimir contribution to the internal energy of the system, manifested as the vacuum energy for global AdS spacetime in odd dimensions. Because of this reason, we derive a quantum statistical relation directly from the Euclidean action and not from the integration of the first law of thermodynamics. To this end, we employ a background-independent regularization scheme which consists, in addition to the bulk action, of counterterms that depend on both extrinsic and intrinsic curvatures of the boundary (Kounterterm series). This procedure results in a consistent inclusion of the vacuum energy and chemical potential in the thermodynamic description for Einstein-Gauss-Bonnet AdS gravity regardless of the explicit form of the nonlinear electrodynamics Lagrangian.

  2. S-duality in AdS/CFT magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Hansen, James; Kraus, Per

    2009-10-01

    We study the nonlinear hydrodynamics of a 2+1 dimensional charged conformal fluid subject to slowly varying external electric and magnetic fields. Following recent work on deriving nonlinear hydrodynamics from gravity, we demonstrate how long wavelength perturbations of the AdS dyonic black brane solution of 4D supergravity are governed by equations equivalent to fluid dynamics equations in the boundary theory. We investigate the implications of S-duality for our system, and derive restrictions imposed on the transport coefficients of a generic fluid invariant under the S operation. We also expand on our earlier work and determine a new set of previously undetermined transport coefficients for the conformal fluid with an AdS gravity dual. Quite surprisingly, we discover that half of the transport coefficients allowed by symmetry vanish in the holographic fluid at linear order in the hydrodynamic expansion.

  3. Search the AGU journals in the ADS Full Text Service

    NASA Astrophysics Data System (ADS)

    Henneken, E.; Accomazzi, A.

    2012-12-01

    ADS Labs is a platform that Smithsonian/NASA Astrophysics Data System has been developing over the last two years. ADS Labs now includes a full-text search interface which users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes present and past astronomical literatures, publications from the main physics journals, and all content published by the AGU. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org. The ADS is funded by NASA grant NNX12AG54G.

  4. Accelerator development in India for ADS programme

    NASA Astrophysics Data System (ADS)

    Singh, P.; Rao, S. V. L. S.; Pande, Rajni; Basak, T.; Roy, Shweta; Aslam, M.; Jain, P.; Srivastava, S. C. L.; Kumar, Rajesh; Nema, P. K.; Kailas, S.; Sahni, V. C.

    2007-02-01

    At BARC, development of a Low Energy High Intensity Proton Accelerator (LEHIPA), as front-end injector of the 1 GeV accelerator for the ADS programme, has been initiated. The major components of LEHIPA (20 MeV, 30 mA) are a 50 keV ECR ion source, a 3 MeV Radio Frequency Quadrupole (RFQ) and a 20 MeV drift tube linac (DTL). The Low Energy Beam Transport (LEBT) and Medium Energy Beam Transport (MEBT) lines match the beam from the ion source to RFQ and from RFQ to DTL respectively. Design of these systems has been completed and fabrication of their prototypes has started. Physics studies of the 20-1000 MeV part of the Linac are also in progress. In this paper, the present status of this project is presented.

  5. 47 CFR 95.139 - Adding a small base station or a small control station.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Adding a small base station or a small control... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.139 Adding a small... or more small base stations or a small control station may be added to a GMRS system at any...

  6. 47 CFR 95.139 - Adding a small base station or a small control station.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Adding a small base station or a small control... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.139 Adding a small... or more small base stations or a small control station may be added to a GMRS system at any...

  7. 48 CFR 252.229-7006 - Value added tax exclusion (United Kingdom).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Value added tax exclusion... CLAUSES Text of Provisions And Clauses 252.229-7006 Value added tax exclusion (United Kingdom). As prescribed in 229.402-70(f), use the following clause: Value Added Tax Exclusion (United Kingdom) (JUN...

  8. 48 CFR 252.229-7006 - Value added tax exclusion (United Kingdom).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Value added tax exclusion... CLAUSES Text of Provisions And Clauses 252.229-7006 Value added tax exclusion (United Kingdom). As prescribed in 229.402-70(f), use the following clause: Value Added Tax Exclusion (United Kingdom) (JUN...

  9. 48 CFR 453.213 - Simplified Acquisition and other simplified purchase procedures (AD-838).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... other simplified purchase procedures (AD-838). 453.213 Section 453.213 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CLAUSES AND FORMS FORMS Prescription of Forms 453.213 Simplified Acquisition and other simplified purchase procedures (AD-838). Form AD-838, Purchase Order, is prescribed...

  10. 17 CFR 240.17Ad-13 - Annual study and evaluation of internal accounting control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... internal accounting control. 240.17Ad-13 Section 240.17Ad-13 Commodity and Securities Exchanges SECURITIES... Company Rules § 240.17Ad-13 Annual study and evaluation of internal accounting control. (a) Accountant's... accountant concerning the transfer agent's system of internal accounting control and related procedures...

  11. Boundary conditions for General Relativity on AdS3 and the KdV hierarchy

    NASA Astrophysics Data System (ADS)

    Pérez, Alfredo; Tempo, David; Troncoso, Ricardo

    2016-06-01

    It is shown that General Relativity with negative cosmological constant in three spacetime dimensions admits a new family of boundary conditions being labeled by a nonnegative integer k. Gravitational excitations are then described by "boundary gravitons" that fulfill the equations of the k-th element of the KdV hierarchy. In particular, k = 0 corresponds to the Brown-Henneaux boundary conditions so that excitations are described by chiral movers. In the case of k = 1, the boundary gravitons fulfill the KdV equation and the asymptotic symmetry algebra turns out to be infinite-dimensional, abelian and devoid of central extensions. The latter feature also holds for the remaining cases that describe the hierarchy ( k > 1). Our boundary conditions then provide a gravitational dual of two noninteracting left and right KdV movers, and hence, boundary gravitons possess anisotropic Lifshitz scaling with dynamical exponent z = 2 k + 1. Remarkably, despite spacetimes solving the field equations are locally AdS, they possess anisotropic scaling being induced by the choice of boundary conditions. As an application, the entropy of a rotating BTZ black hole is precisely recovered from a suitable generalization of the Cardy formula that is compatible with the anisotropic scaling of the chiral KdV movers at the boundary, in which the energy of AdS spacetime with our boundary conditions depends on z and plays the role of the central charge. The extension of our boundary conditions to the case of higher spin gravity and its link with different classes of integrable systems is also briefly addressed.

  12. Integrated nuclear data utilisation system for innovative reactors.

    PubMed

    Yamano, N; Hasegawa, A; Kato, K; Igashira, M

    2005-01-01

    A five-year research and development project on an integrated nuclear data utilisation system was initiated in 2002, for developing innovative nuclear energy systems such as accelerator-driven systems. The integrated nuclear data utilisation system will be constructed as a modular code system, which consists of two sub-systems: the nuclear data search and plotting sub-system, and the nuclear data processing and utilisation sub-system. The system will be operated with a graphical user interface in order to enable easy utilisation through the Internet by both nuclear design engineers and nuclear data evaluators. This paper presents an overview of the integrated nuclear data utilisation system, describes the development of a prototype system to examine the operability of the user interface and discusses specifications of the two sub-systems. PMID:16381697

  13. Integrated nuclear data utilisation system for innovative reactors.

    PubMed

    Yamano, N; Hasegawa, A; Kato, K; Igashira, M

    2005-01-01

    A five-year research and development project on an integrated nuclear data utilisation system was initiated in 2002, for developing innovative nuclear energy systems such as accelerator-driven systems. The integrated nuclear data utilisation system will be constructed as a modular code system, which consists of two sub-systems: the nuclear data search and plotting sub-system, and the nuclear data processing and utilisation sub-system. The system will be operated with a graphical user interface in order to enable easy utilisation through the Internet by both nuclear design engineers and nuclear data evaluators. This paper presents an overview of the integrated nuclear data utilisation system, describes the development of a prototype system to examine the operability of the user interface and discusses specifications of the two sub-systems.

  14. Development of BBD Adding-Delay Architecture for Ultrasonic Micro Array Sensor

    NASA Astrophysics Data System (ADS)

    Tanaka, Tsunehisa; Mo, Yaowu; Tsuchitani, Akira; Inoue, Koji; Arita, Shigeru; Suzuki, Yoshihiko; Yamashita, Kaoru; Okuyama, Masanori

    Bucket Brigade Device (BBD) adding-delay architecture was proposed as the analog beamformer for piezoelectric micromachined ultrasonic sensor phased array. BBD adding-delay architecture were used both as delay and adding elements, and the input signals were distributed adding in the process of delay. This architecture was useful to reduce chip area, simplify system design, and realize on-chip integration. Combining piezoelectric micromachined ultrasonic array sensors and the analog delay-sum circuits successfully performed two-dimensional object detection.

  15. Thick domain walls in AdS black hole spacetimes

    SciTech Connect

    Moderski, Rafal; Rogatko, Marek

    2006-08-15

    Equations of motion for a real self-gravitating scalar field in the background of a black hole with negative cosmological constant were solved numerically. We obtain a sequence of static axisymmetric solutions representing thick domain wall cosmological black hole systems, depending on the mass of black hole, cosmological parameter and the parameter binding black hole mass with the width of the domain wall. For the case of extremal cosmological black hole the expulsion of scalar field from the black hole strongly depends on it.

  16. Accident analysis of the windowless target system

    SciTech Connect

    Bianchi, F.; Ferri, R.

    2006-07-01

    Transmutation systems are able to reduce the radio-toxicity and amount of High-Level Wastes (HLW), which are the main concerns related to the peaceful use of nuclear energy, and therefore they should make nuclear energy more easily acceptable by population. A transmutation system consists of a sub-critical fast reactor, an accelerator and a Target System, where the spallation reactions needed to sustain the chain reaction take place. Three options were proposed for the Target System within the European project PDS-XADS (Preliminary Design Studies on an Experimental Accelerator Driven System): window, windowless and solid. This paper describes the constraints taken into account in the design of the windowless Target System for the large Lead-Bismuth-Eutectic cooled XADS and deals with the results of the calculations performed to assess the behaviour of the target during some accident sequences related to pump trips. (authors)

  17. Supercurrent: Vector hair for an AdS black hole

    SciTech Connect

    Basu, Pallab; Mukherjee, Anindya; Shieh, H.-H.

    2009-02-15

    Hartnoll, Herzog, and Horowitz [Phys. Rev. Lett. 101, 031601 (2008).] discuss a holographic black hole solution which exhibits a superconductorlike transition. In the superconducting phase the black holes show infinite DC conductivity. This gives rise to the possibility of deforming the solutions by turning on a time independent current (supercurrent), without any electric field. This type of deformation does not exist for normal (nonsuperconducting) black holes, due to the no-hair theorems. In this paper we have studied such a supercurrent solution and the associated phase diagram. Interestingly, we have found a 'special point' (critical point) in the phase diagram where the second order superconducting phase transition becomes first order. Supercurrent in superconducting materials is a well studied phenomenon in condensed matter systems. We have found some qualitative agreement with known results.

  18. Inseparability of photon-added Gaussian states

    SciTech Connect

    Li Hongrong; Li Fuli; Zhu Shiyao

    2007-06-15

    The inseparability of photon-added Gaussian states which are generated from two-mode Gaussian states by adding photons is investigated. According to the established inseparability conditions [New J. Phys. 7, 211 (2005); Phys. Rev. Lett. 96, 050503 (2006)], we find that even if a two-mode Gaussian state is separable, the photon-added Gaussian state becomes entangled when the purity of the Gaussian state is larger than a certain value. The lower bound of entanglement of symmetric photon-added Gaussian states is derived. The result shows that entanglement of the photon-added Gaussian states is involved with high-order moment correlations. We find that fidelity of teleporting coherent states cannot be raised by employing the photon-added Gaussian states as a quantum channel of teleportation.

  19. ADS Labs: Supporting Information Discovery in Science Education

    NASA Astrophysics Data System (ADS)

    Henneken, E. A.

    2013-04-01

    The SAO/NASA Astrophysics Data System (ADS) is an open access digital library portal for researchers in astronomy and physics, operated by the Smithsonian Astrophysical Observatory (SAO) under a NASA grant, successfully serving the professional science community for two decades. Currently there are about 55,000 frequent users (100+ queries per year), and up to 10 million infrequent users per year. Access by the general public now accounts for about half of all ADS use, demonstrating the vast reach of the content in our databases. The visibility and use of content in the ADS can be measured by the fact that there are over 17,000 links from Wikipedia pages to ADS content, a figure comparable to the number of links that Wikipedia has to OCLC's WorldCat catalog. The ADS, through its holdings and innovative techniques available in ADS Labs, offers an environment for information discovery that is unlike any other service currently available to the astrophysics community. Literature discovery and review are important components of science education, aiding the process of preparing for a class, project, or presentation. The ADS has been recognized as a rich source of information for the science education community in astronomy, thanks to its collaborations within the astronomy community, publishers and projects like ComPADRE. One element that makes the ADS uniquely relevant for the science education community is the availability of powerful tools to explore aspects of the astronomy literature as well as the relationship between topics, people, observations and scientific papers. The other element is the extensive repository of scanned literature, a significant fraction of which consists of historical literature.

  20. On shape dependence of holographic entanglement entropy in AdS4/CFT3

    NASA Astrophysics Data System (ADS)

    Fonda, Piermarco; Seminara, Domenico; Tonni, Erik

    2015-12-01

    We study the finite term of the holographic entanglement entropy of finite domains with smooth shapes and for four dimensional gravitational backgrounds. Analytic expressions depending on the unit vectors normal to the minimal area surface are obtained for both stationary and time dependent spacetimes. The special cases of AdS4, asymptotically AdS4 black holes, domain wall geometries and Vaidya-AdS backgrounds have been analysed explicitly. When the bulk spacetime is AdS4, the finite term is the Willmore energy of the minimal area surface viewed as a submanifold of the three dimensional flat Euclidean space. For the static spacetimes, some numerical checks involving spatial regions delimited by ellipses and non convex domains have been performed. In the case of AdS4, the infinite wedge has been also considered, recovering the known analytic formula for the coefficient of the logarithmic divergence.

  1. Unfolding mixed-symmetry fields in AdS and the BMV conjecture: II. Oscillator realization

    NASA Astrophysics Data System (ADS)

    Boulanger, Nicolas; Iazeolla, Carlo; Sundell, Per

    2009-07-01

    Following the general formalism presented in arXiv:0812.3615 — referred to as Paper I — we derive the unfolded equations of motion for tensor fields of arbitrary shape and mass in constantly curved backgrounds by radial reduction of Skvortsov's equations in one higher dimension. The complete unfolded system is embedded into a single master field, valued in a tensorial Schur module realized equivalently via either bosonic (symmetric basis) or fermionic (anti-symmetric basis) vector oscillators. At critical masses the reduced Weyl zero-form modules become indecomposable. We explicitly project the latter onto the submodules carrying Metsaev's massless representations. The remainder of the reduced system contains a set of Stückelberg fields and dynamical potentials that leads to a smooth flat limit in accordance with the Brink-Metsaev-Vasiliev (BMV) conjecture. In the unitary massless cases in AdS, we identify the Alkalaev-Shaynkman-Vasiliev frame-like potentials and explicitly disentangle their unfolded field equations.

  2. Analytic self-gravitating Skyrmions, cosmological bounces and AdS wormholes

    NASA Astrophysics Data System (ADS)

    Ayón-Beato, Eloy; Canfora, Fabrizio; Zanelli, Jorge

    2016-01-01

    We present a self-gravitating, analytic and globally regular Skyrmion solution of the Einstein-Skyrme system with winding number w = ± 1, in presence of a cosmological constant. The static spacetime metric is the direct product R ×S3 and the Skyrmion is the self-gravitating generalization of the static hedgehog solution of Manton and Ruback with unit topological charge. This solution can be promoted to a dynamical one in which the spacetime is a cosmology of the Bianchi type-IX with time-dependent scale and squashing coefficients. Remarkably, the Skyrme equations are still identically satisfied for all values of these parameters. Thus, the complete set of field equations for the Einstein-Skyrme-Λ system in the topological sector reduces to a pair of coupled, autonomous, nonlinear differential equations for the scale factor and a squashing coefficient. These equations admit analytic bouncing cosmological solutions in which the universe contracts to a minimum non-vanishing size, and then expands. A non-trivial byproduct of this solution is that a minor modification of the construction gives rise to a family of stationary, regular configurations in General Relativity with negative cosmological constant supported by an SU (2) nonlinear sigma model. These solutions represent traversable AdS wormholes with NUT parameter in which the only "exotic matter" required for their construction is a negative cosmological constant.

  3. The TRASCO Project

    NASA Astrophysics Data System (ADS)

    Pagani, Carlo

    2002-12-01

    TRASCO is a joint INFN/ENEA program, started in 1998, aiming at the design and the technological investigation of the main components of an accelerator driven system (ADS) for nuclear waste transmutation. The proposed 30 mA, 1 GeV, proton linac (TRASCO-AC) is briefly outlined, together with the ongoing R&D work on several key components.

  4. Kaon Decays from AdS/QCD

    SciTech Connect

    Schvellinger, Martin

    2008-07-28

    We briefly review one of the current applications of the AdS/CFT correspondence known as AdS/QCD and discuss about the calculation of four-point quark-flavour current correlation functions and their applications to the calculation of observables related to neutral kaon decays and neutral kaon mixing processes.

  5. Next-Generation A/D Sampler ADS3000+ for VLBI2010

    NASA Technical Reports Server (NTRS)

    Takefuji, Kazuhiro; Takeuchi, Hiroshi; Tsutsumi, Masanori; Koyama, Yasuhiro

    2010-01-01

    A high-speed A/D sampler, called ADS3000+, has been developed in 2008, which can sample one analog signal up to 4 Gbps to versatile Linux PC. After A/D conversion, the ADS3000+ can perform digital signal processing such as real-time DBBC (Digital Base Band Conversion) and FIR filtering such as simple CW RFI filtering using the installed FPGAs. A 4 Gsps fringe test with the ADS3000+ has been successfully performed. The ADS3000+ will not exclusively be used for VLBI but will also be employed in other applications.

  6. An improved AFS phase for AdS3 string integrability

    NASA Astrophysics Data System (ADS)

    Abbott, Michael C.; Aniceto, Inês

    2015-04-01

    We propose a number of modifications to the classical term in the dressing phase for integrable strings in AdS3 ×S3 ×S3 ×S1, and check these against existing perturbative calculations, crossing symmetry, and the semiclassical limit of the Bethe equations. The principal change is that the phase for different masses should start with a term Q1Q2, like the one-loop AdS3 dressing phase, rather than Q2Q3 as for the original AdS5 AFS phase.

  7. On circular strings in (AdS3 × S 3)ϰ

    NASA Astrophysics Data System (ADS)

    Banerjee, Aritra; Panigrahi, Kamal L.

    2016-09-01

    The so called one-parameter (often called ϰ) deformed AdS string sigma models have attracted a lot of attention lately in the study of integrability in string theory. We construct various circular string solutions in the (AdS3 × S 3) ϰ background and describe the characteristics of such solutions qualitatively. We study the Bohr-Sommerfeld like quantization for these string states to characterise the motion. Further we find a `long' string limit of such circular strings in the ϰ-deformed AdS3 and find a novel dependence of the oscillation number on the energy in the next to leading order expansion.

  8. 80. (Credit JTL) Filters added in 1947 and 1975 in ...

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

    80. (Credit JTL) Filters added in 1947 and 1975 in foreground (south of 1942 filter building). Tops of fluorine tanks for new (1980) fluoridation system can barely be seen over left edge of filters. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  9. INTERIOR OF BARN HAYLOFT, LOOKING WEST (Charles Arnold added a ...

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

    INTERIOR OF BARN HAYLOFT, LOOKING WEST (Charles Arnold added a Cleaning Mill to the barn's hayloft c. 1960. This photograph shows the elevator, chaff shoot, and metal funnel that still remain. The barn's gambrel roof is supported by a three-hinged arch truss system) - Arnold Farm, Barn, 1948 Arnold Road, Coupeville, Island County, WA

  10. The Principal Axis Approach to Value-Added Calculation

    ERIC Educational Resources Information Center

    He, Qingping; Tymms, Peter

    2014-01-01

    The assessment of the achievement of students and the quality of schools has drawn increasing attention from educational researchers, policy makers, and practitioners. Various test-based accountability and feedback systems involving the use of value-added techniques have been developed for evaluating the effectiveness of individual teaching…

  11. The Value in Value Added Depends on the Ecology

    ERIC Educational Resources Information Center

    Braun, Henry

    2015-01-01

    In this commentary, the author states that, as the contributions of the focal articles make clear, there is much to learn about how value-added models (VAMs) are actually used in a variety of settings. Indeed, it is important to remember that VAM scores are but one component of a complex evaluation system that can play out differently in different…

  12. The eleven observations of comets between 687 AD and 1114 AD recorded in the Anglo Saxon Chronicle

    NASA Technical Reports Server (NTRS)

    Mardon, E. G.; Williams, J.; Mardon, A. A.

    1992-01-01

    This research paper is an examination of the eleven cometary references (679AD, 729AD, 892AD, 950AD, 975AD, 995AD, 1066AD, 1097AD, 1106AD, 1110AD and 1114AD) found in the various manuscripts of The Anglo Saxon Chronicle between 678 AD and 1114 AD. The manuscripts contain more than 35 celestial observations. This is an examination of astronomical phenomena and other climatic or natural events, that are described in The Anglo Saxon Chronicle, which is also referred to as The Old English Annals.

  13. Adding helicity to inflationary magnetogenesis

    SciTech Connect

    Caprini, Chiara; Sorbo, Lorenzo E-mail: sorbo@physics.umass.edu

    2014-10-01

    The most studied mechanism of inflationary magnetogenesis relies on the time-dependence of the coefficient of the gauge kinetic term F{sub μν} F{sup μν}. Unfortunately, only extremely finely tuned versions of the model can consistently generate the cosmological magnetic fields required by observations. We propose a generalization of this model, where also the pseudoscalar invariant F{sub μν}  F-tilde {sup μν} is multiplied by a time dependent function. The new parity violating term allows more freedom in tuning the amplitude of the field at the end of inflation. Moreover, it leads to a helical magnetic field that is amplified at large scales by magnetohydrodynamical processes during the radiation dominated epoch. As a consequence, our model can satisfy the observational lower bounds on fields in the intergalactic medium, while providing a seed for the galactic dynamo, if inflation occurs at an energy scale ranging from 10{sup 5} to 10{sup 10} GeV. Such energy scale is well below that suggested by the recent BICEP2 result, if the latter is due to primordial tensor modes. However, the gauge field is a source of tensors during inflation and generates a spectrum of gravitational waves that can give a sizable tensor to scalar ratio r=O(0.2) even if inflation occurs at low energies. This system therefore evades the Lyth bound. For smaller values of r, lower values of the inflationary energy scale are required. The model predicts fully helical cosmological magnetic fields and a chiral spectrum of primordial gravitational waves.

  14. Inflation in AdS/CFT

    SciTech Connect

    Freivogel, Ben; Hubeny, Veronika E.; Maloney, Alexander; Myers, Rob; Rangamani, Mukund; Shenker, Stephen; /Stanford U., Phys. Dept.

    2005-10-07

    We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.

  15. Superradiance instability of small rotating AdS black holes in arbitrary dimensions

    NASA Astrophysics Data System (ADS)

    Delice, Ã.-zgür; Durǧut, Türküler

    2015-07-01

    We investigate the stability of D dimensional singly rotating Myers-Perry-AdS black holes under superradiance against scalar field perturbations. It is well known that small four dimensional rotating or charged Anti-de Sitter (AdS) black holes are unstable against superradiance instability of a scalar field. Recent works extended the existence of this instability to five dimensional rotating charged AdS black holes or static charged AdS black holes in arbitrary dimensions. In this paper we analytically prove that rotating small AdS black holes in arbitrary dimensions also shows superradiance instability irrespective of the value of the (positive) angular momentum quantum number. To do this we solve the Klein-Gordon equation in the slow rotation, low frequency limit. By using the asymptotic matching technique, we are able to calculate the real and imaginary parts of the correction terms to the frequency of the scalar field due to the presence of the black hole, confirming the presence of superradiance instability. We see that, unlike in the case of static AdS black holes, the analytical method is valid for rotating AdS black holes for any value of angular momentum number and spacetime dimensions. For comparison we derive the corresponding correction terms for Myers-Perry black holes in the black hole bomb formalism in the Appendix and see that the results are in agreement.

  16. The Value Added National Project. Technical Report: Primary 4. Value-Added Key Stage 1 to Key Stage 2.

    ERIC Educational Resources Information Center

    Tymms, Peter

    This is the fourth in a series of technical reports that have dealt with issues surrounding the possibility of national value-added systems for primary schools in England. The main focus has been on the relative progress made by students between the ends of Key Stage 1 (KS1) and Key Stage 2 (KS2). The analysis has indicated that the strength of…

  17. Adding New Colours to Interferometry

    NASA Astrophysics Data System (ADS)

    2004-04-01

    ESO PR Photo 09a/04 AMBER at the VLT Interferometric Laboratory [Preview - JPEG: 534 x 400 pix - 68k] [Normal - JPEG: 1067 x 800 pix - 665k] Caption: ESO PR Photo 09a/04 shows the AMBER instrument in the VLT Interferometric Laboratory at Paranal. The AMBER instrument is mounted on a 4.2 x 1.5 m precision optical table, placed in the VLT Interferometric Laboratory at the top of the Paranal mountain, cf. PR Photo 09/04. The total shipping weight of the instrument and its extensive associated electronics was almost 4 tons. AMBER is the latest addition to the VLTI and completes the planned set of first-generation instruments for this facility. It continues the success story of the interferometric mode of the VLT, following the unique initial scientific results obtained by the VINCI and MIDI instruments, the installation of the first MACAO adaptive optics systems and the recent arrival of the first 1.8-m Auxiliary Telescope at Paranal (ESO PR 01/04). The interferometric technique can achieve images, as sharp as those of a telescope with a diameter equivalent to the distance between the telescopes in the interferometer. For the VLTI, this distance can be as large as 205 meters, resulting in a resolution of 0.001 arcsec in the near-infrared spectral region (at 1 μm wavelength). The latter measure corresponds to about 2 metres on the surface of the Moon. AMBER is a very powerful complement to the other instruments already installed at the VLTI and offered to the astronomical community. AMBER is indeed sensitive in the near-infrared wavelength region of 1 to 2.5 microns while the present instrument, MIDI, covers the 8 to 13 microns range. Moreover, AMBER will be able to perform spectroscopic measurements with a spectral resolution up to 10,000. ESO PR Photo 09b/04 ESO PR Photo 09b/04 The AMBER instrument (detail) [Preview - JPEG: 435 x 400 pix - 74k] [Normal - JPEG: 870 x 800 pix - 722k] Caption: ESO PR Photo 09b/04 shows in the foreground some of the mirrors and optical

  18. Metadata-driven Ad Hoc Query of Patient Data

    PubMed Central

    Deshpande, Aniruddha M.; Brandt, Cynthia; Nadkarni, Prakash M.

    2002-01-01

    Clinical study data management systems (CSDMSs) have many similarities to clinical patient record systems (CPRSs) in their focus on recording clinical parameters. Requirements for ad hoc query interfaces for both systems would therefore appear to be highly similar. However, a clinical study is concerned primarily with collective responses of groups of subjects to standardized therapeutic interventions for the same underlying clinical condition. The parameters that are recorded in CSDMSs tend to be more diverse than those required for patient management in non-research settings, because of the greater emphasis on questionnaires for which responses to each question are recorded separately. The differences between CSDMSs and CPRSs are reflected in the metadata that support the respective systems' operation, and need to be reflected in the query interfaces. The authors describe major revisions of their previously described CSDMS ad hoc query interface to meet CSDMS needs more fully, as well as its porting to a Web-based platform. PMID:12087118

  19. Period-adding bifurcations and chaos in a bubble column.

    PubMed

    Piassi, Viviane S M; Tufaile, Alberto; Sartorelli, Jose Carlos

    2004-06-01

    We obtained period-adding bifurcations in a bubble formation experiment. Using the air flow rate as the control parameter in this experiment, the bubble emission from the nozzle in a viscous fluid undergoes from single bubbling to a sequence of periodic bifurcations of k to k+1 periods, occasionally interspersed with some chaotic regions. Our main assumption is that this period-adding bifurcation in bubble formation depends on flow rate variations in the chamber under the nozzle. This assumption was experimentally tested by placing a tube between the air reservoir and the chamber under the nozzle in the bubble column experiment. By increasing the tube length, more period-adding bifurcations were observed. We associated two main types of bubble growth to the flow rate fluctuations inside the chamber for different bubbling regimes. We also studied the properties of piecewise nonlinear maps obtained from the experimental reconstructed attractors, and we concluded that this experiment is a spatially extended system.

  20. Supergravity background of the λ-deformed AdS3 × S3 supercoset

    NASA Astrophysics Data System (ADS)

    Chervonyi, Yuri; Lunin, Oleg

    2016-09-01

    We construct the solution of type IIB supergravity describing the integrable λ-deformation of the AdS3 ×S3 supercoset. While the geometry corresponding to the deformation of the bosonic coset has been found in the past, our background is more natural for studying superstrings, and several interesting features distinguish our solution from its bosonic counterpart. We also report progress towards constructing the λ-deformation of the AdS5 ×S5 supercoset.

  1. Adding biotic complexity alters the metabolic benefits of mutualism.

    PubMed

    Harcombe, William R; Betts, Alex; Shapiro, Jason W; Marx, Christopher J

    2016-08-01

    Mutualism is ubiquitous in nature and plays an integral role in most communities. To predict the eco-evolutionary dynamics of mutualism it is critical to extend classic pair-wise analysis to include additional species. We investigated the effect of adding a third species to a pair-wise mutualism in a spatially structured environment. We tested the hypotheses that selection for costly excretions in a focal population (i) decreases when an exploiter is added (ii) increases when a third mutualist is added relative to the pair-wise scenario. We assayed the selection acting on Salmonella enterica when it exchanges methionine for carbon in an obligate mutualism with an auxotrophic Escherichia coli. A third bacterium, Methylobacterium extorquens, was then added and acted either as an exploiter of the carbon or third obligate mutualist depending on the nitrogen source. In the tripartite mutualism M. extorquens provided nitrogen to the other species. Contrary to our expectations, adding an exploiter increased selection for methionine excretion in S. enterica. Conversely, selection for cooperation was lower in the tripartite mutualism relative to the pair-wise system. Genome-scale metabolic models helped identify the mechanisms underlying these changes in selection. Our results highlight the utility of connecting metabolic mechanisms and eco-evolutionary dynamics. PMID:27272242

  2. Studies on the ADS/CFT correspondence

    NASA Astrophysics Data System (ADS)

    Muck, Wolfgang

    1999-11-01

    This thesis summarizes original research on the topic of the ``AdS/CFT correspondence.'' This correspondence, which was first conjectured by Maldacena [ Adv. Theor. Math. Phys. 2, 231 (1998)] and subsequently formulated by Gubser, Klebanov and Polyakov [Phys. Lett. B 428, 105 (1998) and by Witten [Adv. Theor. Math. Phys. 2, 253 (1998)], relates field theories on (d + 1)-dimensional anti-de Sitter (AdS) spaces and conformal field theories (CFTs) in d dimensions with each other. Its main prediction is that the correlation functions of certain quantum CFTs are determined by the dynamics of classical field theories on AdS spaces. Starting from a correspondence formula provided by the authors above, several CFT correlation functions are calculated and agreement with the forms dictated by conformal invariance is found. The necessary renormalization is carried out in the ``ɛ- prescription.'' Details of renormalization and the breaking of conformal symmetries in special cases are investigated by means of the example of the scalar field. The ``asymptotic prescription'' is used to prove a suggestion by Klebanov and Witten [hep- th/9905104] about the treatment of irregular boundary conditions valid to all orders of perturbation theory. The treatment of AdS gravity, which enables the calculation of correlation functions of CFT energy momentum tensors, is carried out in the time slicing formalism. The calculated two-point functions and Weyl anomalies agree with results known from pure CFT considerations. The Wess Zumino model on AdS4 is discussed as an example containing supersymmetry. It is shown that the model yields the correlation functions of conformal fields belonging to a d = 3, N = 1 superconformal multiplet.

  3. 48 CFR 453.270 - Request for contract action (AD-700).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Request for contract action (AD-700). 453.270 Section 453.270 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CLAUSES AND FORMS FORMS Prescription of Forms 453.270 Request for contract action (AD-700). Form...

  4. Oxidatively modified proteins in Alzheimer’s disease (AD), mild cognitive impairment and animal models of AD: role of Abeta in pathogenesis

    PubMed Central

    Sultana, Rukhsana; Perluigi, Marzia

    2009-01-01

    Oxidative stress has been implicated in the pathogenesis of a number of diseases including Alzheimer’s disease (AD). The oxidative stress hypothesis of AD pathogenesis, in part, is based on β-amyloid peptide (Aβ)-induced oxidative stress in both in vitro and in vivo studies. Oxidative modification of the protein may induce structural changes in a protein that might lead to its functional impairment. A number of oxidatively modified brain proteins were identified using redox proteomics in AD, mild cognitive impairment (MCI) and Aβ models of AD, which support a role of Aβ in the alteration of a number of biochemical and cellular processes such as energy metabolism, protein degradation, synaptic function, neuritic growth, neurotransmission, cellular defense system, long term potentiation involved in formation of memory, etc. All the redox proteomics-identified brain proteins fit well with the appearance of the three histopathological hallmarks of AD, i.e., synapse loss, amyloid plaque formation and neurofibrillary tangle formation and suggest a direct or indirect association of the identified proteins with the pathological and/or biochemical alterations in AD. Further, Aβ models of AD strongly support the notion that oxidative stress induced by Aβ may be a driving force in AD pathogenesis. Studies conducted on arguably the earliest stage of AD, MCI, may elucidate the mechanism(s) leading to AD pathogenesis by identifying early markers of the disease, and to develop therapeutic strategies to slow or prevent the progression of AD. In this review, we summarized our findings of redox proteomics identified oxidatively modified proteins in AD, MCI and AD models. PMID:19288120

  5. ADS on WWW: Doubling Yearly for Five Years

    NASA Astrophysics Data System (ADS)

    Kurtz, M. J.; Eichhorn, G.; Accomazzi, A.; Grant, C. S.; Murray, S. S.

    1998-12-01

    It is now five years since the NASA ADS Abstract Service became available on the World Wide Web, in late winter of 1994. Following the explosive growth of the service (when compared with the old propriatory network access system) in the early months of WWW service, ADS growth has settled to doubling yearly. Currently ADS users make 440,000 queries per month, and receive 8,000,000 bibliographic references and 70,000 full-text articles, as well as abstracts, citation histories, links to data, and links to other data centers. Of the 70,000 full-text articles accessed through ADS each month, already 30% are via pointers to the electronic journals. This number is certain to increase. It is difficult to determine the exact number of ADS users. We track usage by the number of unique ``cookies'' which access ADS, and by the number of unique IP addresses. There are difficulties with each technique. In addition many non-astronomers find ADS through portal sites like Yahoo, which skews the statistics. 10,000 unique cookies access the full-text articles each month, 17,000 make queries, and 30,000 visit the site. 91% of full-text users have cookies, but only 65% of site visitors. From another perspective the number of IP addresses from a single typical research site (STScI) which access the full-text data is within 5% of the number of unique cookies assiociated with full-text use from stsci.edu, and also within 5% of the number of AAS members listing an STScI address. The number of unique IP addresses from STScI which make any sort of query to ADS is 40% higher than this. Those who access the full-text average one article per day, those who make queries average two per day. We believe nearly all active astronomy researchers, as well as students and affiliated professionals use ADS on a regular basis.

  6. Genes Might Explain Hispanics' Added Longevity

    MedlinePlus

    ... University of California, Los Angeles. For example, the biological clock measured Hispanic women's "genetic" age as 2. ... and how long they live," he added. The biological clock used in the new study evaluates the ...

  7. Underweight Seniors May Have Added Alzheimer's Risk

    MedlinePlus

    ... fullstory_160278.html Underweight Seniors May Have Added Alzheimer's Risk Study links lower body weight to increased ... older adults' risk of the memory-robbing disorder Alzheimer's disease, new research suggests. The study included 280 ...

  8. Heat kernels on cone of AdS2 and k-wound circular Wilson loop in AdS5 × S5 superstring

    NASA Astrophysics Data System (ADS)

    Bergamin, R.; Tseytlin, A. A.

    2016-04-01

    We compute the one-loop world-sheet correction to partition function of {{AdS}}5× {{{S}}}5 superstring that should be representing k-fundamental circular Wilson loop in planar limit. The 2d metric of the minimal surface ending on k-wound circle at the boundary is that of a cone of AdS2 with deficit 2π (1-k). We compute the determinants of 2d fluctuation operators by first constructing heat kernels of scalar and spinor Laplacians on the cone using the Sommerfeld formula. The final expression for the k-dependent part of the one-loop correction has simple integral representation but is different from earlier results.

  9. Junk Food Ads Sway Kids' Preferences

    MedlinePlus

    ... Kids' Preferences Children under 8 most vulnerable to marketing's effects, study says To use the sharing features ... studies. The researchers found that ads and other marketing for products high in sugar or salt have ...

  10. Testing the AdS/CFT Correspondence

    SciTech Connect

    Klebanov, Igor R.

    2008-07-28

    This lecture begins with some history and basic facts about string theory and its connections with strong interactions. Comparisons of stacks of Dirichlet branes with curved backgrounds produced by them are used to motivate the AdS/CFT correspondence between superconformal gauge theory and string theory on a product of Anti-de Sitter space and a compact manifold. The ensuing duality between semi-classical spinning strings and long gauge theory operators is briefly reviewed. We go on to describe a recent test of the AdS/CFT correspondence using the Wilson loop cusp anomaly as a function of the coupling, which also enters dimensions of high-spin operators. Finally, strongly coupled thermal SYM theory is explored via a black hole in 5-dimensional AdS space, which leads to explicit results for its entropy and shear viscosity.

  11. Trust Based Routing in Ad Hoc Network

    NASA Astrophysics Data System (ADS)

    Talati, Mikita V.; Valiveti, Sharada; Kotecha, K.

    Ad Hoc network often termed as an infrastructure-less, self- organized or spontaneous network.The execution and survival of an ad-hoc network is solely dependent upon the cooperative and trusting nature of its nodes. However, this naive dependency on intermediate nodes makes the ad-hoc network vulnerable to passive and active attacks by malicious nodes and cause inflict severe damage. A number of protocols have been developed to secure ad-hoc networks using cryptographic schemes, but all rely on the presence of trust authority. Due to mobility of nodes and limitation of resources in wireless network one interesting research area in MANET is routing. This paper offers various trust models and trust based routing protocols to improve the trustworthiness of the neighborhood.Thus it helps in selecting the most secure and trustworthy route from the available ones for the data transfer.

  12. Adding stress plot function to NASTRAN

    NASA Technical Reports Server (NTRS)

    Katoh, S.

    1978-01-01

    Stress plot function was developed and added to the NASTRAN level 15.5. Computed stress distribution can be displayed by this function, with vectors showing the principal stresses of the finite elements over the specified portions of the structure. NASTRAN is reviewed in the aspect of plotting capabilities. Stress tensor field is examined in preparation of stress display. Then the stress plot function as added to the NASTRAN is described. A sample plotout by this function is shown.

  13. The Mutation SK(ad-3A) Cancels the Dominance of ad-3A+ over ad-3A in the Ascus of Neurospora

    PubMed Central

    Delange, A. M.

    1981-01-01

    A newly induced mutant of Neurospora, when crossed with an ad-3A mutant, produces asci with four viable black and four inviable white ascospores. The survivors always contain the new mutant allele, never ad-3A. The new allele, which is called SK(ad-3A) (for spore killer of ad-3A), is located at or very near the ad-3A locus.—In crosses homozygous for ad-3A, each ascus contains only inviable white ascospores. This defect in ascospore maturation is complemented by the wild-type allele, ad-3A+ (crosses heterozygous for ad-3A and ad-3A+ produce mainly viable ascospores), but it is not complemented by the new SK(ad-3A) allele (all ad-3A ascospores from crosses heterozygous for SK(ad-3A) and ad-3A are white and inviable). In crosses homozygous for SK(ad-3A) or heterozygous for SK(ad-3A) and ad-3A+, each ascus contains only viable black ascospores. SK(ad-3A) does not require adenine for growth, and forced heterokaryons between SK(ad-3A) and ad-3A grow at wild-type rates and produce conidia of both genotypes with approximately equal frequency. Thus, the action of SK(ad-3A) is apparently restricted to ascospore formation. Possible mechanisms of the action of this new allele are discussed. PMID:6456169

  14. Image Ads and Issue Ads in U.S. Presidential Advertising: Using Videostyle To Explore Stylistic Differences in Televised Political Ads From 1952 to 2000.

    ERIC Educational Resources Information Center

    Johnston, Anne; Kaid, Lynda Lee

    2002-01-01

    Explores the differences in techniques, strategies, narratives, and symbols used in 1,213 television issue ads and image ads from 13 U.S. presidential campaigns. Concludes that although the majority of both types of ads were positive, negative appeals dominated a higher percentage of issue ads as compared with image ads. (SG)

  15. Comment on the scaling function in AdS4 × Bbb CBbb P3

    NASA Astrophysics Data System (ADS)

    Gromov, Nikolay; Mikhaylov, Victor

    2009-04-01

    The folded spinning string in AdS3 gives us an important insight into AdS/CFT duality. Recently its one-loop energy was analyzed in the context of AdS4/CFT3 by McLoughlin and Roiban arXiv:0807.3965, by Alday, Arutyunov and Bykov arXiv:0807.4400 and by Krishnan arXiv:0807.4561. They computed the spectrum of the fluctuations around the classical solution. In this paper we reproduce their results using the algebraic curve technique and show that under some natural resummation of the fluctuation energies the one-loop energy agrees perfectly with the predictions of arXiv:0807.0777. This provides a further support of the all-loop Bethe equations and of the AdS4 × Bbb CBbb P3 algebraic curve developed in arXiv:0807.0437.

  16. AdS5×S(5) mirror model as a string sigma model.

    PubMed

    Arutyunov, Gleb; van Tongeren, Stijn J

    2014-12-31

    Doing a double Wick rotation in the world sheet theory of the light cone AdS5×S(5) superstring results in an inequivalent, so-called mirror theory that plays a central role in the field of integrability in the AdS-CFT correspondence. We show that this mirror theory can be interpreted as the light cone theory of a free string on a different background. This background is related to dS5×H(5) by a double T-duality, and has hidden supersymmetry. The geometry can also be extracted from an integrable deformation of the AdS5×S(5) sigma model, and we prove the observed mirror duality of these deformed models at the bosonic level as a byproduct. While we focus on AdS5×S(5), our results apply more generally. PMID:25615306

  17. Supersymmetric black holes in AdS4 from very special geometry

    NASA Astrophysics Data System (ADS)

    Gnecchi, Alessandra; Halmagyi, Nick

    2014-04-01

    Supersymmetric black holes in AdS spacetime are inherently interesting for the AdS/CFT correspondence. Within a four dimensional gauged supergravity theory coupled to vector multiplets, the only analytic solutions for regular, supersymmetric, static black holes in AdS4 are those in the STU-model due to Cacciatori and Klemm. We study a class of U (1)-gauged supergravity theories coupled to vector multiplets which have a cubic prepotential, the scalar manifold is then a very special Kähler manifold. When the resulting very special Kähler manifold is a homogeneous space, we find analytic solutions for static, supersymmetric AdS4 black holes with vanishing axions. The horizon geometries of our solutions are constant curvature Riemann surfaces of arbitrary genus.

  18. AdS5×S(5) mirror model as a string sigma model.

    PubMed

    Arutyunov, Gleb; van Tongeren, Stijn J

    2014-12-31

    Doing a double Wick rotation in the world sheet theory of the light cone AdS5×S(5) superstring results in an inequivalent, so-called mirror theory that plays a central role in the field of integrability in the AdS-CFT correspondence. We show that this mirror theory can be interpreted as the light cone theory of a free string on a different background. This background is related to dS5×H(5) by a double T-duality, and has hidden supersymmetry. The geometry can also be extracted from an integrable deformation of the AdS5×S(5) sigma model, and we prove the observed mirror duality of these deformed models at the bosonic level as a byproduct. While we focus on AdS5×S(5), our results apply more generally.

  19. Impact: The District of Columbia Public Schools Effectiveness Assessment System for School-Based Personnel 2011-2012. Group 2: Grades 1-12 General Education Teachers without Individual Value-Added Student Achievement Data

    ERIC Educational Resources Information Center

    District of Columbia Public Schools, 2011

    2011-01-01

    IMPACT is the District of Columbia Public Schools' (DCPS) system for assessing and rewarding the performance of teachers and other school-based staff. This system is called IMPACT because the adults serving in the DCPS have the ability to make a dramatic, positive impact on students' lives. The system is designed to help staff become more…

  20. Higher spin contributions to holographic fluid dynamics in AdS5/CFT4

    NASA Astrophysics Data System (ADS)

    Lee, Seungjin; Polyakov, Dimitri

    2014-08-01

    We calculate the graviton's β function in the AdS string-theoretic sigma model, perturbed by vertex operators for Vasiliev's higher spin gauge fields in AdS5. The result is given by βmn=Rmn+4Tmn(g ,u) (with the AdS radius set to 1 and the graviton polarized along the AdS5 boundary), with the matter stress-energy tensor given by that of conformal holographic fluid in d =4, evaluated at the temperature given by T =1/π. The stress-energy tensor is given by Tmn=gmn+4umun+∑NTmn(N) where u is the vector excitation satisfying u2=-1 and N is the order of the gradient expansion in the dissipative part of the tensor. We calculate the contributions up to N =2. The higher spin excitations contribute to the β function, ensuring the overall Weyl covariance of the matter stress tensor. We conjecture that the structure of gradient expansion in d =4 conformal hydrodynamics at higher orders is controlled by the higher spin operator algebra in AdS5.

  1. AdS and Lifshitz scalar hairy black holes in Gauss-Bonnet gravity

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Fan, Zhong-Ying; Zhu, Lu-Yao

    2016-09-01

    We consider Gauss-Bonnet (GB) gravity in general dimensions, which is nonminimally coupled to a scalar field. By choosing a scalar potential of the type V (ϕ )=2 Λ0+1/2 m2ϕ2+γ4ϕ4 , we first obtain large classes of scalar hairy black holes with spherical/hyperbolic/planar topologies that are asymptotic to locally anti- de Sitter (AdS) space-times. We derive the first law of black hole thermodynamics using Wald formalism. In particular, for one class of the solutions, the scalar hair forms a thermodynamic conjugate with the graviton and nontrivially contributes to the thermodynamical first law. We observe that except for one class of the planar black holes, all these solutions are constructed at the critical point of GB gravity where there exist unique AdS vacua. In fact, a Lifshitz vacuum is also allowed at the critical point. We then construct many new classes of neutral and charged Lifshitz black hole solutions for an either minimally or nonminimally coupled scalar and derive the thermodynamical first laws. We also obtain new classes of exact dynamical AdS and Lifshitz solutions which describe radiating white holes. The solutions eventually become AdS or Lifshitz vacua at late retarded times. However, for one class of the solutions, the final state is an AdS space-time with a globally naked singularity.

  2. Maximum amplitudes in transient resonance of distributed-parameter systems / Amplitudy maksymalne w rezonansie przejściowym układów o parametrach rozłożonych

    NASA Astrophysics Data System (ADS)

    Michalczyk, Jerzy

    2012-12-01

    The application of the kinetic energy balance for the estimation maximum amplitudes of continuous systems in the transient resonance excited by the free coasting of unbalanced rotor or piston machines placed on the continuous system - was proposed in the study. The exact as well as the approximate methods were shown. For the typical one- and two-dimensional systems the calculation formulae, useful for the engineering practice, were given.

  3. Curation and integration of observational metadata in ADS

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto

    2015-08-01

    This presentation discusses the current curation of archive bibliographies and their indexing in the NASA Astrophysics Data System (ADS). Integration of these bibliographies provides convenient cross-linking of resources between ADS and the data archives, affording greater visibility to both data products and the literature associated with them. There are practical incentives behind this effort: it has been shown that astronomy articles which provide links to on-line datasets have a citation advantage over similar articles which don’t link to data. Additionally, the availability of paper-based metrics makes it possible for archivists and program managers use them in order to assess the impact of an instrument, facility, funding or observing program.The primary data curated by ADS is bibliographic information provided by publishers or harvested by ADS from conference proceeding sites and repositories. This core bibliographic information is then further enriched by ADS via the generation of citations and usage data, and through the aggregation of external bibliographic information. Important sources of such additional information are the metadata describing observing proposals from the major missions and archives, the curated bibliographies for data centers, and the sets of links between archival observations and published papers.While ADS solicits and welcomes the inclusion of this data from US and foreign data centers, the curation of bibliographies, observing proposals and links to data products is left to the archives which host the data and which have the expertise and resources to properly maintain them. In this regard, the role of ADS is one of resource aggregation through crowdsourced curation, providing a lightweight discovery mechanism through its search capabilities. While limited in scope, this level of aggregation can still be quite useful in supporting the discovery and selection of data products associated with publications. For instance, a user can

  4. Effect of ZnO nanoparticles in R290/R600a (50/50) based vapour compression refrigeration system added via lubricant oil on compressor suction and discharge characteristics

    NASA Astrophysics Data System (ADS)

    Kumar, Ravinder; Singh, Jagdev

    2016-10-01

    The primary source of energy consumption in a vapour compression refrigeration system is a compressor. The possibility of a reduction in the work of compression may leads to enhance the compressor suction and discharge characteristics and the overall performance of the refrigeration system. The present experimental investigation based upon the study of ZnO nanoparticles in a vapour compression refrigeration system using hydrocarbon blend R290/R600a (50/50) as a refrigerant. The zinc oxide nanoparticles are appended with system refrigerant via compressor lubricating oil. The results observed that by using different weight concentrations of nanoparticles in R290/R600a refrigeration system, both the compressor suction and discharge pressures and temperatures were reduced compared to conventional system. The viscosity of mineral oil with the addition of nanoparticles increases. The compressor energy consumption was reduced by 7.48 % using (0.2-1.0) wt% concentrations of nanoparticles. The COP of the refrigeration system has been increased by about 46 % with the addition of nanoparticles. Thus, the ZnO nanoparticles worked efficiently in the R290/R600a refrigeration system.

  5. Autoimmune Manifestations in the 3xTg-AD Model of Alzheimer's Disease

    PubMed Central

    Marchese, Monica; Cowan, David; Head, Elizabeth; Ma, Donglai; Karimi, Khalil; Ashthorpe, Vanessa; Kapadia, Minesh; Zhao, Hui; Davis, Paulina; Sakic, Boris

    2015-01-01

    Background Immune system activation is frequently reported in patients with Alzheimer's disease (AD). However, it remains unknown whether this is a cause, a consequence, or an epiphenomenon of brain degeneration. Objective The present study examines whether immunological abnormalities occur in a well-established murine AD model and if so, how they relate temporally to behavioral deficits and neuropathology. Methods A broad battery of tests was employed to assess behavioral performance and autoimmune/inflammatory markers in 3xTg-AD (AD) mice and wild type controls from 1.5 to 12 months of age. Results Aged AD mice displayed severe manifestations of systemic autoimmune/inflammatory disease, as evidenced by splenomegaly, hepatomegaly, elevated serum levels of anti-nuclear/anti-dsDNA antibodies, low hematocrit, and increased number of double-negative T splenocytes. However, anxiety-related behavior and altered spleen function were evident as early as 2 months of age, thus preceding typical AD-like brain pathology. Moreover, AD mice showed altered olfaction and impaired “cognitive” flexibility in the first 6 months of life, suggesting mild cognitive impairment-like manifestations before general learning/memory impairments emerged at an older age. Interestingly, all of these features were present in 3xTg-AD mice prior to significant amyloid-β or tau pathology. Conclusion The results indicate that behavioral deficits in AD mice develop in parallel with systemic autoimmune/inflammatory disease. These changes antedate AD-like neuropathology, thus supporting a causal link between autoimmunity and aberrant behavior. Consequently, 3xTg-AD mice may be a useful model in elucidating the role of immune system in the etiology of AD. PMID:24150111

  6. Spinning strings at one-loop in AdS4 × Bbb P3

    NASA Astrophysics Data System (ADS)

    McLoughlin, Tristan; Roiban, Radu

    2008-12-01

    We analyze the folded spinning string in AdS4 × Bbb P3 with spin S in AdS4 and angular momentum J in Bbb P3. We calculate the one-loop correction to its energy in the scaling limit of both ln S and J large with their ratio kept fixed. This result should correspond to the first subleading strong coupling correction to the anomalous dimension of operators of the type Tr(DS(Y†Y)J) in the dual Script N = 6 Chern-Simons-matter theory. Our result appears to depart from the predictions for the generalized scaling function found from the all-loop Bethe equations conjectured for this AdS4/CFT3 duality. We comment on the possible origin of this difference.

  7. QCD Condensates and Holographic Wilson Loops for Asymptotically AdS Spaces

    SciTech Connect

    Quevedo, R. Carcasses; Goity, Jose L.; Trinchero, Roberto C.

    2014-02-01

    The minimization of the Nambu-Goto (NG) action for a surface whose contour defines a circular Wilson loop of radius a placed at a finite value of the coordinate orthogonal to the border is considered. This is done for asymptotically AdS spaces. The condensates of dimension n = 2, 4, 6, 8, and 10 are calculated in terms of the coefficients in the expansion in powers of the radius a of the on-shell subtracted NG action for small a->0. The subtraction employed is such that it presents no conflict with conformal invariance in the AdS case and need not introduce an additional infrared scale for the case of confining geometries. It is shown that the UV value of the gluon condensates is universal in the sense that it only depends on the first coefficients of the difference with the AdS case.

  8. Asymptotically AdS Solutions of Five Dimensional Gravity-Dilaton Theory

    NASA Astrophysics Data System (ADS)

    Nata Atmaja, Ardian

    2016-08-01

    We search for Asymptotically AdS solutions of the background metric in which dilaton back reacts to gravity in five-dimensional gravity-dilaton theory. The five-dimensional gravity-dilaton theory generally appears in the context of the low energy effective action of closed string theory in the Einstein frame. In particular, we consider dilaton which are minimally coupled to gravity in which the potential for dilation is taken to be simple and contain only one exponential term parametrized by a constant a. We solve analytically and show for a simple constant dilaton potential it appears there are no black hole solutions if we turn on the dilaton contribution. On the other hand, the exponential dilaton potential has black hole solutions but they are not in general Asymptotically AdS. We argue that there are some possible Asymptotically AdS black hole solutions in the range of |a| \\lt \\frac{4}{\\sqrt{6}}

  9. Superstring theory on AdS 2× S2 as a coset supermanifold

    NASA Astrophysics Data System (ADS)

    Berkovits, N.; Bershadsky, M.; Hauer, T.; Zhukov, S.; Zwiebach, B.

    We quantize the superstring on the AdS 2× S2 background with Ramond-Ramond flux using a PSU(1,1|2)/ U(1)× U(1) sigma model with a WZ term. One-loop conformal invariance of the model is guaranteed by a general mechanism which holds for coset spaces G/ H where G is Ricci-flat and H is the invariant locus of a Z4 automorphism of G. This mechanism gives conformal theories for the PSU(1,1|2)× PSU(2|2)/ SU(2)× SU(2) and PSU(2,2|4)/ SO(4,1)× SO(5) coset spaces, suggesting our results might be useful for quantizing the superstring on AdS 3× S3 and AdS 5× S5 backgrounds.

  10. Photon gas thermodynamics in dS and AdS momentum spaces

    NASA Astrophysics Data System (ADS)

    Gorji, M. A.; Hosseinzadeh, V.; Nozari, K.; Vakili, B.

    2016-07-01

    In this paper, we study thermostatistical properties of a photon gas in the framework of two deformed special relativity models defined by the cosmological coordinatizations of the de Sitter (dS) and anti-de Sitter (AdS) momentum spaces. The dS model is a doubly special relativity theory in which an ultraviolet length scale is invariant under the deformed Lorentz transformations. For the case of the AdS model, however, the Lorentz symmetry breaks at the high energy regime. We show that the existence of a maximal momentum in dS momentum space leads to maximal pressure and temperature at the thermodynamical level, while maximal internal energy and entropy arise for the case of the AdS momentum space due to the existence of a maximal kinematical energy. These results show that the thermodynamical duality of these models is very similar to their well-known kinematical duality.

  11. Rhazes (865-925 AD), the icon of Persian cardiology.

    PubMed

    Nezhad, Golnoush Sadat Mahmoudi; Dalfardi, Behnam

    2014-12-20

    For many long centuries, the function of the human cardiovascular system was an important issue among scholars of different eras and areas. Abubakr Muhammad ibn Zakariyya al-Razi (865-925 AD), known by the Latin name Rhazes, was one of the scholars concerned with this issue. This physician is recognized as the first great scientist of the Golden Age of Islamic Medicine (9th-12th centuries AD). He authored Kitab al-Mansuri (Liber Al-Mansuri), a ten-volume medical encyclopedia that covers a large number of medical subjects. The first chapter of this book is allocated to human anatomy and functions. In this article, we review the chapter from Al-Mansuri that deals with Rhazes' views on the cardiovascular system. PMID:25465822

  12. Interpolating from Bianchi attractors to Lifshitz and AdS spacetimes

    NASA Astrophysics Data System (ADS)

    Kachru, Shamit; Kundu, Nilay; Saha, Arpan; Samanta, Rickmoy; Trivedi, Sandip P.

    2014-03-01

    We construct classes of smooth metrics which interpolate from Bianchi attractor geometries of Types II, III, VI and IX in the IR to Lifshitz or AdS 2 × S 3 geometries in the UV. While we do not obtain these metrics as solutions of Einstein gravity coupled to a simple matter field theory, we show that the matter sector stress-energy required to support these geometries (via the Einstein equations) does satisfy the weak, and therefore also the null, energy condition. Since Lifshitz or AdS 2 × S 3 geometries can in turn be connected to AdS 5 spacetime, our results show that there is no barrier, at least at the level of the energy conditions, for solutions to arise connecting these Bianchi attractor geometries to AdS 5 spacetime. The asymptotic AdS 5 spacetime has no non-normalizable metric deformation turned on, which suggests that furthermore, the Bianchi attractor geometries can be the IR geometries dual to field theories living in flat space, with the breaking of symmetries being either spontaneous or due to sources for other fields. Finally, we show that for a large class of flows which connect two Bianchi attractors, a C-function can be defined which is monotonically decreasing from the UV to the IR as long as the null energy condition is satisfied. However, except for special examples of Bianchi attractors (including AdS space), this function does not attain a finite and non-vanishing constant value at the end points.

  13. Flowing along the edge: Spinning up black holes in AdS spacetimes with test particles

    NASA Astrophysics Data System (ADS)

    Rocha, Jorge V.; Santarelli, Raphael

    2014-03-01

    We investigate the consequences of throwing point particles into odd-dimensional Myers-Perry black holes in asymptotically anti-de Sitter (AdS) backgrounds. We restrict our attention to the case in which the angular momenta of the background geometry are all equal. This process allows us to test the generalization of the weak cosmic censorship conjecture to asymptotically AdS spacetimes in higher dimensions. We find no evidence for overspinning in D =5,7,9 and 11 dimensions. Instead, test particles carrying the maximum possible angular momentum that still fall into an extremal rotating black hole generate a flow along the curve of extremal solutions.

  14. FAST TRACK COMMUNICATION: The hidden symmetry of higher dimensional Kerr NUT AdS spacetimes

    NASA Astrophysics Data System (ADS)

    Kubiznák, David; Frolov, Valeri P.

    2007-02-01

    It is well known that four-dimensional Kerr NUT AdS spacetime possesses the hidden symmetry associated with the Killing Yano tensor. This tensor is 'universal' in the sense that there exist coordinates where it does not depend on any of the free parameters of the metric. Recently, the general higher dimensional Kerr NUT AdS solutions of the Einstein equations were obtained. We demonstrate that all these metrics with arbitrary rotation and NUT parameters admit a universal Killing Yano tensor. We give an explicit presentation of the Killing Yano tensor and associated second rank Killing tensor and briefly discuss their properties.

  15. {{AdS}}_{3}/{{CFT}}_{2} and q-Poincaré superalgebras

    NASA Astrophysics Data System (ADS)

    Strömwall, Joakim; Torrielli, Alessandro

    2016-10-01

    We discover that a certain deformation of the 1+1 dimensional Poincaré superalgebra is exactly realised in the massless sector of the {{AdS}}3/{{CFT}}2 integrable scattering problem. Deformed Poincaré superalgebras were previously noticed to appear in the {{AdS}}5/{{CFT}}4 correspondence—which displays only massive excitations, but they were there only a partial symmetry. We obtain a representation of the boost operator and its coproduct, and show that the comultiplication exactly satisfies the homomorphism property. We present a classical limit, and finally speculate on an analogy with the physics of phonons.

  16. New Features in the ADS Abstract Service

    NASA Astrophysics Data System (ADS)

    Eichhorn, G.; Accomazzi, A.; Grant, C. S.; Kurtz, M. J.; ReyBacaicoa, V.; Murray, S. S.

    2001-11-01

    The ADS Abstract Service contains over 2.3 million references in four databases: Astronomy/Astrophysics/Planetary Sciences, Instrumentation, Physics/Geophysics, and Preprints. We provide abstracts and articles free to the astronomical community for all major and many smaller astronomy journals, PhD theses, conference proceedings, and technical reports. These four databases can be queried either separately of jointly. The ADS also has scanned 1.3 million pages in 180,000 articles in the ADS Article Service. This literature archive contains all major Astronomy journals and many smaller journals, as well as conference proceedings, including the abstract books from all the LPSCs back to volume 2. A new feature gives our users the ability to see list of articles that were also read by the readers of a given article. This is a powerful tool to find out what current articles are relevant in a particular field of study. We have recently expanded the citation and reference query capabilities. It allows our users to select papers for which they want to see references or citations and then retrieve these citations/references. Another new capability is the ability to sort a list of articles by their citation count. As usual, users should be reminded that the citations in ADS are incomplete because we do not obtain reference lists from all publishers. In addition, we cannot match all references (e.g. in press, private communications, author errors, some conference papers, etc.). Anyone using the citations for analysis of publishing records should keep this in mind. More work on expanding the citation and reference features is planned over the next year. ADS Home Page http://ads.harvard.edu/

  17. Proposed Framework for Determining Added Mass of Orion Drogue Parachutes

    NASA Technical Reports Server (NTRS)

    Fraire, Usbaldo, Jr.; Dearman, James; Morris, Aaron

    2011-01-01

    The Crew Exploration Vehicle (CEV) Parachute Assembly System (CPAS) project is executing a program to qualify a parachute system for a next generation human spacecraft. Part of the qualification process involves predicting parachute riser tension during system descent with flight simulations. Human rating the CPAS hardware requires a high degree of confidence in the simulation models used to predict parachute loads. However, uncertainty exists in the heritage added mass models used for loads predictions due to a lack of supporting documentation and data. Even though CPAS anchors flight simulation loads predictions to flight tests, extrapolation of these models outside the test regime carries the risk of producing non-bounding loads. A set of equations based on empirically derived functions of skirt radius is recommended as the simplest and most viable method to test and derive an enhanced added mass model for an inflating parachute. This will increase confidence in the capability to predict parachute loads. The selected equations are based on those published in A Simplified Dynamic Model of Parachute Inflation by Dean Wolf. An Ames 80x120 wind tunnel test campaign is recommended to acquire the reefing line tension and canopy photogrammetric data needed to quantify the terms in the Wolf equations and reduce uncertainties in parachute loads predictions. Once the campaign is completed, the Wolf equations can be used to predict loads in a typical CPAS Drogue Flight test. Comprehensive descriptions of added mass test techniques from the Apollo Era to the current CPAS project are included for reference.

  18. The forecaster's added value in QPF

    NASA Astrophysics Data System (ADS)

    Turco, M.; Milelli, M.

    2010-03-01

    : - despite the overall improvement in global scale and the fact that the resolution of the limited area models has increased considerably over recent years, the QPF produced by the meteorological models involved in this study has not improved enough to allow its direct use: the subjective HQPF continues to offer the best performance for the period +24 h/+48 h (i.e. the warning period in the Piemonte system); - in the forecast process, the step where humans have the largest added value with respect to mathematical models, is the communication. In fact the human characterization and communication of the forecast uncertainty to end users cannot be replaced by any computer code; - eventually, although there is no novelty in this study, we would like to show that the correct application of appropriated statistical techniques permits a better definition and quantification of the errors and, mostly important, allows a correct (unbiased) communication between forecasters and decision makers.

  19. Comparison of the Life Cycles of Genetically Distant Species C and Species D Human Adenoviruses Ad6 and Ad26 in Human Cells

    PubMed Central

    Turner, Mallory A.; Middha, Sumit; Hofherr, Sean E.

    2015-01-01

    level by 34%. Head-to-head comparison in human lung cells by NGS revealed that the two viruses generally conform to our general understanding of the Ad transcriptional program. However, fine mapping revealed subtle and strong differences in how these two viruses execute these programs, including differences in the balance of E1A and E1B mRNAs and in E3 immune evasion genes. This suggests that not all adenoviruses behave like Ad2 and Ad5 and that they may have unique strategies to infect cells and evade the immune system. PMID:26423951

  20. 76 FR 9329 - Efficiency Initiative Effort To Reduce Non-Value-Added Costs Imposed on Industry by Department of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... Efficiency Initiative Effort To Reduce Non-Value-Added Costs Imposed on Industry by Department of Defense... overhead costs, but do not contribute to value added in systems and services delivered to the Department... information about some additional areas of non-value- added cost. Submissions should specifically...

  1. Fitting Value-Added Models in R

    ERIC Educational Resources Information Center

    Doran, Harold C.; Lockwood, J. R.

    2006-01-01

    Value-added models of student achievement have received widespread attention in light of the current test-based accountability movement. These models use longitudinal growth modeling techniques to identify effective schools or teachers based upon the results of changes in student achievement test scores. Given their increasing popularity, this…

  2. Adding a Statistical Wrench to the "Toolbox"

    ERIC Educational Resources Information Center

    DesJardins, Stephen L.; Lindsay, Nathan K.

    2008-01-01

    This paper demonstrates a formal statistical test that can be used to help researchers make decisions about alternative statistical model specifications. This test is commonly used by researchers who would like to test whether adding new variables to a model improves the model fit. However, we demonstrate that this formal test can also be employed…

  3. "Value Added" Gauge of Teaching Probed

    ERIC Educational Resources Information Center

    Viadero, Debra

    2009-01-01

    A new study by a public and labor economist suggests that "value added" methods for determining the effectiveness of classroom teachers are built on some shaky assumptions and may be misleading. The study, due to be published in February in the "Quarterly Journal of Economics," is the first of a handful of papers now in the publishing pipeline…

  4. Double relaxation via AdS/CFT

    NASA Astrophysics Data System (ADS)

    Amiri-Sharifi, S.; Ali-Akbari, M.; Kishani-Farahani, A.; Shafie, N.

    2016-08-01

    We exploit the AdS/CFT correspondence to investigate thermalization in an N = 2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under influence of an external electric field which leads to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS5 ×S5 background. In the dual gravity theory an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory side. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions, where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe the formation of two separate apparent horizons on the brane. This means that the state of the gauge theory experiences two different temperature regimes during its time evolution.

  5. Imago Mundi, Imago AD, Imago ADNI

    PubMed Central

    2014-01-01

    Since the launch in 2003 of the Alzheimer’s Disease Neuroimaging Initiative (ADNI) in the USA, ever growing, similarly oriented consortia have been organized and assembled around the world. The various accomplishments of ADNI have contributed substantially to a better understanding of the underlying physiopathology of aging and Alzheimer’s disease (AD). These accomplishments are basically predicated in the trinity of multimodality, standardization and sharing. This multimodality approach can now better identify those subjects with AD-specific traits that are more likely to present cognitive decline in the near future and that might represent the best candidates for smaller but more efficient therapeutic trials – trials that, through gained and shared knowledge, can be more focused on a specific target or a specific stage of the disease process. In summary, data generated from ADNI have helped elucidate some of the pathophysiological mechanisms underpinning aging and AD pathology, while contributing to the international effort in setting the groundwork for biomarker discovery and establishing standards for early diagnosis of AD. PMID:25478022

  6. Adding Users to the Website Design Process

    ERIC Educational Resources Information Center

    Tomeo, Megan L.

    2012-01-01

    Alden Library began redesigning its website over a year ago. Throughout the redesign process the students, faculty, and staff that make up the user base were added to the conversation by utilizing several usability test methods. This article focuses on the usability testing conducted at Alden Library and delves into future usability testing, which…

  7. The AD Nurse: Prepared to be Prepared

    ERIC Educational Resources Information Center

    Beverly, Lynne; Junker, Mary H.

    1977-01-01

    It is not enough for the new associate degree (AD) nursing graduate to know the theory and be willing to learn. She must also have some skill in providing basic nursing care. Examples of applicants, both ADNs and BSNs, are described to illustrate the nursing talent necessary to practice sensitively and effectively. (Editor/TA)

  8. Value Added School Review Field Guide

    ERIC Educational Resources Information Center

    Alberta Education, 2009

    2009-01-01

    The "Value-Added School Review (VSR)" is an analytical model designed to assist schools in identifying and addressing opportunities for school improvement. The model works best when it is focused purposefully on students and the student learning outcomes as defined in the "Guide to Education". It complements the processes described in Alberta…

  9. "Value Added" Proves Beneficial to Teacher Prep

    ERIC Educational Resources Information Center

    Sawchuk, Stephen

    2012-01-01

    The use of "value added" information appears poised to expand into the nation's teacher colleges, with more than a dozen states planning to use the technique to analyze how graduates of training programs fare in classrooms. Supporters say the data could help determine which teacher education pathways produce teachers who are at least as…

  10. Drag force in AdS/CFT

    SciTech Connect

    Gubser, Steven S.

    2006-12-15

    The AdS/CFT correspondence and a classical test string approximation are used to calculate the drag force on an external quark moving in a thermal plasma of N=4 super-Yang-Mills theory. This computation is motivated by the phenomenon of jet-quenching in relativistic heavy ion collisions.

  11. Anomaly Detection Techniques for Ad Hoc Networks

    ERIC Educational Resources Information Center

    Cai, Chaoli

    2009-01-01

    Anomaly detection is an important and indispensable aspect of any computer security mechanism. Ad hoc and mobile networks consist of a number of peer mobile nodes that are capable of communicating with each other absent a fixed infrastructure. Arbitrary node movements and lack of centralized control make them vulnerable to a wide variety of…

  12. Value-Added Analysis in Instruction

    ERIC Educational Resources Information Center

    Nicholson, Michael R.; Brown, Jeffrey R.

    2010-01-01

    Value-added data provide a viable alternative for gauging school effectiveness--one virtually free of the confounding effects of student demographics and other factors relating to student learning. How is it different from other measuring methods? It concentrates on growth, rather than attainment. This strengthens the concept and measurement of…

  13. Adding Test Generation to the Teaching Machine

    ERIC Educational Resources Information Center

    Bruce-Lockhart, Michael; Norvell, Theodore; Crescenzi, Pierluigi

    2009-01-01

    We propose an extension of the Teaching Machine project, called Quiz Generator, that allows instructors to produce assessment quizzes in the field of algorithm and data structures quite easily. This extension makes use of visualization techniques and is based on new features of the Teaching Machine that allow third-party visualizers to be added as…

  14. Evaluating Special Educator Effectiveness: Addressing Issues Inherent to Value-Added Modeling

    ERIC Educational Resources Information Center

    Steinbrecher, Trisha D.; Selig, James P.; Cosbey, Joanna; Thorstensen, Beata I.

    2014-01-01

    States are increasingly using value-added approaches to evaluate teacher effectiveness. There is much debate regarding whether these methods should be employed and, if employed, what role such methods should play in comprehensive teacher evaluation systems. In this article, we consider the use of value-added modeling (VAM) to evaluate special…

  15. The Politics and Statistics of Value-Added Modeling for Accountability of Teacher Preparation Programs

    ERIC Educational Resources Information Center

    Lincove, Jane Arnold; Osborne, Cynthia; Dillon, Amanda; Mills, Nicholas

    2014-01-01

    Despite questions about validity and reliability, the use of value-added estimation methods has moved beyond academic research into state accountability systems for teachers, schools, and teacher preparation programs (TPPs). Prior studies of value-added measurement for TPPs test the validity of researcher-designed models and find that measuring…

  16. 48 CFR 252.229-7006 - Value Added Tax Exclusion (United Kingdom)

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (United Kingdom) 252.229-7006 Section 252.229-7006 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.229-7006 Value Added Tax Exclusion (United Kingdom) As prescribed in 229.402-70(f), use the follow clause: Value Added Tax Exclusion (United Kingdom) (DEC 2011)...

  17. 48 CFR 252.229-7006 - Value Added Tax Exclusion (United Kingdom)

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (United Kingdom) 252.229-7006 Section 252.229-7006 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.229-7006 Value Added Tax Exclusion (United Kingdom) As prescribed in 229.402-70(f), use the follow clause: Value Added Tax Exclusion (United Kingdom) (DEC 2011)...

  18. 48 CFR 252.229-7006 - Value Added Tax Exclusion (United Kingdom)

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (United Kingdom) 252.229-7006 Section 252.229-7006 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.229-7006 Value Added Tax Exclusion (United Kingdom) As prescribed in 229.402-70(f), use the follow clause: Value Added Tax Exclusion (United Kingdom) (DEC 2011)...

  19. Alzheimer disease: from inherited to sporadic AD-crossing the biomarker bridge.

    PubMed

    Hampel, Harald; Lista, Simone

    2012-11-01

    Whether dominantly inherited variants of Alzheimer disease (AD) and 'sporadic' forms exhibit similar pathophysiological and biomarker signatures remains unresolved. A landmark study has proposed a biomarker progression model of dominantly inherited AD, but a complex systems biology and physiology approach is required to translate these findings to sporadic disease.

  20. Is School Value Added Indicative of Principal Quality? Working Paper 12. Revised

    ERIC Educational Resources Information Center

    Chiang, Hanley; Lipscomb, Stephen; Gill, Brian

    2014-01-01

    States across the country are developing systems for evaluating school principals on the basis of student achievement growth. A common approach is to hold principals accountable for the value added of their schools--that is, schools' contributions to student achievement growth. In theory, school value added can reflect not only principals'…