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Sample records for chooz b-2 reactor

  1. From double Chooz to triple Chooz - neutrino physics at the Chooz reactor complex

    Huber, Patrick; Kopp, Joachim; Lindner, Manfred; Rolinec, Mark; Winter, Walter

    2006-01-01

    We discuss the potential of the proposed Double Chooz reactor experiment to measure the neutrino mixing angle sin 2 2θ 13 . We especially consider systematical uncertainties and their partial cancellation in a near and far detector operation, and we discuss implications of a delayed near detector startup. Furthermore, we introduce Triple Chooz, which is a possible upgrade scenario assuming a second, larger far detector, which could start data taking in an existing cavern five years after the first far detector. We review the role of the Chooz reactor experiments in the global context of future neutrino beam experiments. We find that both Double Chooz and Triple Chooz can play a leading role in the search for a finite value of sin 2 2θ 13 . Double Chooz could achieve a sensitivity limit of ∼ 2.10 -2 at the 90% confidence level after 5 years while the Triple Chooz setup could give a sensitivity below 10 -2

  2. The double chooz reactor neutrino experiment

    Botella, I Gil [CIEMAT, Basic Research Department, Avenida Complutense, 22, 28040 Madrid (Spain)], E-mail: ines.gil@ciemat.es

    2008-05-15

    The Double Chooz reactor neutrino experiment will be the next detector to search for a non vanishing {theta}{sub 13} mixing angle with unprecedented sensitivity, which might open the way to unveiling CP violation in the leptonic sector. The measurement of this angle will be based in a precise comparison of the antineutrino spectrum at two identical detectors located at different distances from the Chooz nuclear reactor cores in France. Double Chooz is particularly attractive because of its capability to measure sin{sup 2} (2{theta}{sub 13}) to 3{sigma} if sin{sup 2}(2{theta}{sub 13}) > 0.05 or to exclude sin{sup 2}(2{theta}{sub 13}) down to 0.03 at 90% C.L. for {delta}m{sup 2} = 2.5 x 10{sup -3} eV{sup 2} in three years of data taking with both detectors. The construction of the far detector starts in 2008 and the first neutrino results are expected in 2009. The current status of the experiment, its physics potential and design and expected performance of the detector are reviewed.

  3. Chooz B

    Barillot, Pascale; Baize, Jean-Marc

    1997-01-01

    This EDF press communique give information related to the exploitation of the Chooz B NPP. A calendar of the Chooz B1 and B2 NPPs exploitation is given as well as information about the local economic impact. The exploitation of the PWR reactors of the French nuclear sector corresponds to a accumulated experience of 600 year-reactor. Significant technological evolution has been recorded, namely in the test-control system, the turbo-alternator group 'Arabelle' and in the vapor generators. The reactor safety is based on the high professionalism of the exploitation personnel, on the computer-assisted behaviour allowing the choice of operators and on the conception based upon the experience accumulated by the French nuclear power plants, equivalent to 600 year-reactor operation. EDF operates a system of continual surveillance which allows the monitoring the environmental effects caused by the NPP exploitation. The following issues concerning the environment impact are reported in this document: - The effluent releases in the environment; - Health studies conducted in the NPPs' neighbourhood; - New authorizations for waste release; - Radioactive waste management. The report also mentions the French-Belgian partnership in the PWR construction, the socio-economic regional impact of the EDF activities related with the Chooz NPP operation, and the partnership with the associated service companies. Six appendices are attached to the report containing the following information: - A general layout of Chooz NPP; - Chooz B key figures; Chooz B key data; - Security and public information; - Evolution of PWR system in France; - World's nuclear systems

  4. The double chooz experiment: simulation of reactor antineutrino spectra

    Mueller, T.

    2010-01-01

    The Double Chooz experiment aims to study the oscillations of electron antineutrinos produced by the Chooz nuclear power station, located in France, in the Ardennes region. It will lead to an unprecedented accuracy on the value of the mixing angle θ 13 . Improving the current knowledge on this parameter, given by the Chooz experiment, requires a reduction of both statistical and systematic errors, that is to say not only observing a large data sample, but also controlling the experimental uncertainties involved in the production and detection of electron antineutrinos. The use of two identical detectors will cancel most of the experimental systematic uncertainties limiting the sensitivity to the value of the mixing angle. We present in this thesis, simulations of reactor antineutrino spectra that were carried out in order to control the sources of systematic uncertainty related to the production of these particles by the plant. We also discuss our work on controlling the normalization error of the experiment through the precise determination of the number of target protons by a weighing measurement and through the study of the fiducial volume of the detectors which requires an accurate modeling of neutron physics. After three years of data taking with two detectors, Double Chooz will be able to disentangle an oscillation signal for sin 2 2θ 13 ≥ 0.05 (at 3σ) or, if no oscillations are observed, to put a limit of sin 2 2θ 13 ≤ 0.03 at 90% C.L. (author) [fr

  5. Re-examining reactor vessel embrittlement at Chooz A

    Guilleret, J.-C.

    1988-01-01

    The Chooz A PWR experienced an extended shutdown in 1987/88 following indications that the reactor vessel was embrittling more rapidly than expected. Discrepancies between the expected rate and estimates of the actual rate were not easily explained. The huge body of work done since then to establish safety margins and support restart of the plant should provide a model for the owners of other older PWRs grappling with the embrittlement issue. (author)

  6. Chooz A, First Pressurized Water Reactor to be Dismantled in France - 13445

    Boucau, Joseph [Westinghouse Electric Company, 43 rue de l' Industrie, Nivelles (Belgium); Mirabella, C. [Westinghouse Electric France, Orsay (France); Nilsson, Lennart [Westinghouse Electric Sweden, Vaesteraas (Sweden); Kreitman, Paul J. [Westinghouse Electric Company, Lake Bluff, IL 60048 (United States); Obert, Estelle [EDF - DPI - CIDEN, Lyon (France)

    2013-07-01

    Nine commercial nuclear power plants have been permanently shut down in France to date, of which the Chooz A plant underwent an extensive decommissioning and dismantling program. Chooz Nuclear Power Station is located in the municipality of Chooz, Ardennes region, in the northeast part of France. Chooz B1 and B2 are 1,500 megawatt electric (MWe) pressurized water reactors (PWRs) currently in operation. Chooz A, a 305 MWe PWR implanted in two caves within a hill, began operations in 1967 and closed in 1991, and will now become the first PWR in France to be fully dismantled. EDF CIDEN (Engineering Center for Dismantling and Environment) has awarded Westinghouse a contract for the dismantling of its Chooz A reactor vessel (RV). The project began in January 2010. Westinghouse is leading the project in a consortium with Nuvia France. The project scope includes overall project management, conditioning of the reactor vessel (RV) head, RV and RV internals segmentation, reactor nozzle cutting for lifting the RV out of the pit and seal it afterwards, dismantling of the RV thermal insulation, ALARA (As Low As Reasonably Achievable) forecast to ensure acceptable doses for the personnel, complementary vacuum cleaner to catch the chips during the segmentation work, needs and facilities, waste characterization and packaging, civil work modifications, licensing documentation. The RV and RV internals will be segmented based on the mechanical cutting technology that Westinghouse applied successfully for more than 13 years. The segmentation activities cover the cutting and packaging plan, tooling design and qualification, personnel training and site implementation. Since Chooz A is located inside two caves, the project will involve waste transportation from the reactor cave through long galleries to the waste buffer area. The project will end after the entire dismantling work is completed, and the waste storage is outside the caves and ready to be shipped either to the ANDRA (French

  7. Chooz A: a model for the dismantling of water-cooled reactors

    Anon.

    2017-01-01

    The specificity of Chooz-A, the first French pressurized water reactor (PWR), is that the reactor and its major components (pumps, exchangers and cooling circuits) are installed in 2 caves dug out in a hill slope. Chooz-A was operating from 1967 to 1991, in 1993 the fuel was removed and in 2007 EDF received the authorization to dismantle the reactor. In 2012, EDF completed the dismantling of the cave containing the elements of the cooling circuit, a cornerstone was the removing of the four 14 m high steam generators. The dismantling of the pressure vessel began in march 2017, it is the same tools and the same processes that were used for the dismantling of the pressure vessel of the Zorita plant (Spain) in 2016. The end of the Chooz-A dismantling is expected in 2022. The feedback experience will help to standardize practices for the French fleet of PWRs. (A.C.)

  8. International Cooperation for the Dismantling of Chooz A Reactor Pressure Vessel

    Grenouillet, J.J.; Posivak, E.

    2009-01-01

    Chooz A is the first PWR that is being decommissioned in France. The main issue that is conditioning the success of the project is the Reactor Pressure Vessel (RPV) and Reactor Vessel Internals (RVI) segmentation. Whereas Chooz A is the first and unique RPV and RVI being dismantled in France, there are many similar experiences available in the world. Thus the project team was eager to cooperate with other teams facing or being faced with the same issue. A cooperation programme was established in two separate ways: - Benefiting from experience feedback from completed RPV and RVI dismantling projects, - Looking for synergy with future RPV dismantling projects for activities such as segmentation tools design, qualification and manufacturing for example. This paper describes the implementation of this programme and how the outcome of the cooperation was used for the implementation of Chooz-A RPV and RVI segmentation project. It shows also the limits of such a cooperation. (authors)

  9. Double Chooz

    Buck, Christian [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

    2006-05-15

    The goal of the Double Chooz reactor neutrino experiment is to search for the neutrino mixing parameter {theta}{sub 13}. Double Chooz will use two identical detectors at 150 m and 1.05 km distance from the reactor cores. The near detector is used to monitor the reactor {nu}-bar {sub e} flux while the second is dedicated to the search for a deviation from the expected (1/distance){sup 2} behavior. This two detector concept will allow a relative normalization systematic error of ca. 0.6 %. The expected sensitivity for sin{sup 2}2{theta}{sub 13} is then in the range 0.02 - 0.03 after three years of data taking. The antineutrinos will be detected in a liquid scintillator through the capture on protons followed by a gamma cascade, produced by the neutron capture on Gd.

  10. Coherent neutrino scattering with low temperature bolometers at Chooz reactor complex

    Billard, J; Gascon, J; Jesus, M De; Carr, R; Formaggio, J A; Heine, S T; Johnston, J; Leder, A; Sibille, V; Winslow, L; Dawson, J; Lasserre, T; Figueroa-Feliciano, E; Palladino, K J; Vivier, M

    2017-01-01

    We present the potential sensitivity of a future recoil detector for a first detection of the process of coherent elastic neutrino nucleus scattering (CE ν NS). We use the Chooz reactor complex in France as our luminous source of reactor neutrinos. Leveraging the ability to cleanly separate the rate correlated with the reactor thermal power against (uncorrelated) backgrounds, we show that a 10 kg cryogenic bolometric array with 100 eV threshold should be able to extract a CE ν NS signal within one year of running. (paper)

  11. Measurement of the leptonic mixing parameter θ13 at the reactor antineutrino experiment Double Chooz

    Durand, V.

    2014-01-01

    The Double Chooz experiment aims at measuring the neutrino mixing parameter θ 13 by studying the oscillations of ν-bar e produced by the Chooz nuclear reactors located in France. The experimental concept consists in comparing the signal of 2 identical 10.3 m 3 detectors, allowing the cancellation of most of the experimental systematic uncertainties. The near detector, whose goal is the flux normalization and a measurement without oscillation, is expected to be delivered in 2013. The farthest detector from the source is taking data since april 2011 and is sensitive to θ 13 , which is expected to affect both the rate and the shape of measured ν-bar e . In 102 days with far detector only, 4121 ν-bar e candidates have been observed, while the expectation in case of no-oscillation is 4344 ± 165 events. This deficit is interpreted as evidence for ν-bar e disappearance. From a rate and shape analysis, it is found that sin 2 (θ 13 ) = [0.086±0.041(stat.)±0.030(syst)] with Δm 31 2 =2.4*10 -3 eV 2 , while the no-oscillation hypothesis is even excluded at 94.6%. We present in this document the concept and detection method of the Double Chooz experiment, along with its analysis strategy and first results on θ 13 . (author)

  12. Measurement of the mixing leptonic parameter θ13 at the Double Chooz reactor antineutrino experiment

    Durand, V.

    2012-01-01

    The Double Chooz experiment aims at measuring the neutrino mixing parameter θ13 by studying the oscillations of de ν-bar e produced by the Chooz nuclear reactors located in France. The experimental concept consists in comparing the signal of two identical 10.3 m 3 detectors, allowing to cancel most of the experimental systematic uncertainties. The near detector, whose goal is the flux normalization and a measurement without oscillation, is expected to be delivered in 2013. The farthest detector from the source is taking data since April 2011 and is sensitive to θ 13 , which is expected to affect both the rate and the shape of the measured de ν-bar e . In this thesis, are first presented the Double Chooz experiment, with its ν-bar e source, its detection method, and the expected signal and backgrounds. In order to perform a selection, important quantities have to be reconstructed, calibrated, and saved in data files. The channel time offsets determination, the energy and vertex reconstruction algorithm CocoReco, the reconstruction packages of the Common Trunk, and the light trees maker Cheetah are especially presented. Concerning the data analysis, all the selection cuts and results for signal and backgrounds are discussed, particularly the multiplicity cut, the multiple off time window method, the lithium veto cut, and the cosmogenic 9 Li background studies. The Double Chooz experiment observed 8,249 de ν-bar e candidates in 227.93 days in its far detector only. The reactor antineutrino flux prediction used the Bugey 4 flux measurement after correction for differences in core composition. The expectation in case of no-oscillation is 8,937 events and this deficit is interpreted as evidence for ν-bar e disappearance. From a rate and shape analysis, is found sin 2 2θ = 0,109± 0,030 (stat) ± 0,025 (syst), with Δm 2 31 = 2,32 x 10 -3 eV 2 , while the no-oscillation hypothesis is even excluded at 2.9 σ. (author) [fr

  13. Chooz-B1, the new Electricite de France PWR: calculation scheme of neutron leakages from the reactor cavity

    Champion, G.; Thiriet, A.; Vergnaud, T.; Bourdet, L.; Nimal, J.C.; Brandicourt, G.

    1987-04-01

    A new calculation scheme has been set up to assess the neutron field characteristics inside French PWR. In order to take into account multiple neutron scattering and the complexity of the reactor geometry, the use of Monte-Carlo methods have been heavily increased. They are coupled with classical SN.-methods. The main goal aimed at was to find out the neutron field characteristics at the level of the reactor pit openings. These radiation reference sources will be used to check the neutron shielding efficiencies. The new calculation scheme has been applied to CHOOZ-B1, the first unit of the new N4 program. The former results have been compared with the measurement results related to PALUEL-I and II PWR, two units of the previous P4 program. Although the core and the geometry are not entirely similar, it is possible to check with confidence the calculation results along the vessel and at the core midplane level with the measurement results at the same locations. It appears that they are in good agreement. Consequently, the new calculation scheme appears reliable

  14. Status of the double Chooz experiment

    Gonzalez, L.F.G.; Kemp, E. [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Dept. de Raios Cosmicos e Cronologia; Anjos, J.C. dos; Lima Junior, H.P.; Gama, R.; Abrahao, T.; Pepe, I.M. [Centro Brasileiro de Pesquisas Fisicas (MCT/CBPF), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    Full text: The neutrino oscillation experiment Double Chooz, located at the nuclear power plant of Chooz (Ardennes, France), has as purpose to measure the mixing angle {theta}{sub 13} with greater precision than the measurement of its predecessor, the Chooz experiment. For this, the Double Chooz experiment will use antineutrinos generated in both Chooz plant reactors and will make high accuracy measurements of the flux in two different baselines with identical gadolinium-doped-scintillator detectors, that uses the inverse-beta-decay positron and neutron detection as an antineutrino signature. This signature is given by a prompt signal from the positron and a delayed neutron signal, which allow to decrease significantly the uncorrelated background. Other forms of background, in particular the cosmic correlated one, are managed using different technic. The use of two equal detectors at different baselines will allow to better control our systematic errors, in particular the ones associated with the reactor and with the reactor anomaly effect. The first detector (known as the 'far detector', 1050m from the reactors) is already in operation since April 2011 and the second one (known as the 'near detector', 400m from the reactor) is under construction. Thus, in this work we present the main aspects of this neutrino oscillation experiment and results update. (author)

  15. Double Chooz Improved Multi-Detector Measurements

    CERN. Geneva

    2016-01-01

    The Double Chooz experiment (DC) is a reactor neutrino oscillation experiment running at Chooz nuclear power plant (2 reactors) in France. In 2011, DC first reported indication of non-zero θ13 with the far detector (FD) located at the maximum of oscillation effects (i.e. disappearance), thus challenging the CHOOZ non-observation limit. A robust observation of θ13 followed in 2012 by the Daya Bay experiments with multiple detector configurations. Since 2015 DC runs in a multi-detector configuration making thus the impact of several otherwise dominating systematics reduce strongly. DC’s unique almost "iso-flux" site, allows the near detector (ND) to become a direct accurate non-oscillation reference to the FD. Our first multi-detector results at MORIOND-2016 showed an intriguing deviation of θ13 with respect to the world average. We will address this issue in this seminar. The combined "reactor-θ13" measurement is expected to ...

  16. The double Chooz hardware trigger system

    Cucoanes, Andi; Beissel, Franz; Reinhold, Bernd; Roth, Stefan; Stahl, Achim; Wiebusch, Christopher [RWTH Aachen (Germany)

    2008-07-01

    The double Chooz neutrino experiment aims to improve the present knowledge on {theta}{sub 13} mixing angle using two similar detectors placed at {proportional_to}280 m and respectively 1 km from the Chooz power plant reactor cores. The detectors measure the disappearance of reactor antineutrinos. The hardware trigger has to be very efficient for antineutrinos as well as for various types of background events. The triggering condition is based on discriminated PMT sum signals and the multiplicity of groups of PMTs. The talk gives an outlook to the double Chooz experiment and explains the requirements of the trigger system. The resulting concept and its performance is shown as well as first results from a prototype system.

  17. Double Chooz: Results and Perspectives

    Franke, A.J., E-mail: ajfranke@nevis.columbia.edu [Columbia University, New York, New York 10027 (United States)

    2013-04-15

    The Double Chooz experiment has been observing ν{sup ¯}{sub e} from two reactor cores at the Chooz nuclear power station in Ardennes, France, with a single 10.3 m{sup 3} fiducial volume Gd-doped liquid scintillator detector at a flux-weighted average baseline of ∼1050 m. This article reviews results achieved with a detector live time of 227.93 days and exposure of 33.71 GW-ton-years. A total of 8,249 candidate ν{sup ¯}{sub e} events have been observed, compared to an expected 8,937 events in the null-oscillation case: this deficit is interpreted as evidence for ν{sup ¯}{sub e} disappearance. A fit to the observed neutrino rate and spectral shape gives a best-fit value of sin{sup 2}(2θ{sub 13})=0.109±0.030(stat.)±0.025(syst.) at a mass-squared splitting of Δm{sub 31}{sup 2}=2.32×10{sup −3} eV{sup 2}. The null-oscillation hypothesis is excluded by the data at 99.8% CL (2.9σ). The Double Chooz Near Detector is under construction, and analysis efforts to measure neutrino directionality, test Lorentz violation, and measure backgrounds in situ are underway.

  18. Double Chooz: Results and Perspectives

    Franke, A. J.

    2013-04-01

    The Double Chooz experiment has been observing ν from two reactor cores at the Chooz nuclear power station in Ardennes, France, with a single 10.3 m fiducial volume Gd-doped liquid scintillator detector at a flux-weighted average baseline of ˜1050 m. This article reviews results achieved with a detector live time of 227.93 days and exposure of 33.71 GW-ton-years. A total of 8,249 candidate ν events have been observed, compared to an expected 8,937 events in the null-oscillation case: this deficit is interpreted as evidence for ν disappearance. A fit to the observed neutrino rate and spectral shape gives a best-fit value of sin2(2θ13)=0.109±0.030 (stat.)±0.025 (syst.) at a mass-squared splitting of Δm312=2.32×10-3 eV. The null-oscillation hypothesis is excluded by the data at 99.8% CL (2.9σ). The Double Chooz Near Detector is under construction, and analysis efforts to measure neutrino directionality, test Lorentz violation, and measure backgrounds in situ are underway.

  19. Sterile Neutrino Search with the Double Chooz Experiment

    Hellwig, D.; Matsubara, T.; Double Chooz Collaboration

    2017-09-01

    Double Chooz is a reactor antineutrino disappearance experiment located in Chooz, France. A far detector at a distance of about 1 km from reactor cores is operating since 2011; a near detector of identical design at a distance of about 400 m is operating since begin 2015. Beyond the precise measurement of θ 13, Double Chooz has a strong sensitivity to so called light sterile neutrinos. Sterile neutrinos are neutrino mass states not taking part in weak interactions, but may mix with known neutrino states. In this paper, we present an analysis method to search for sterile neutrinos and the expected sensitivity with the baselines of our detectors.

  20. Double Chooz experiment

    Palomares, C.

    2009-01-01

    Double Chooz will use two identical detectors at different distances from the Chooz nuclear power station to search for a non-vanishing value of θ 13 , and, hopefully, to open the way to experiments aspiring to discover CP violation in the leptonic sector. The far detector is expected to be operative by the end of 2009. Installation of the near detector will occur in 2010. Double Chooz has the capacity to exclude sin 2 (2θ 13 ) 31 2 = 2.5 x 10 -3 eV 2 with three years of data running both near and far detectors. (author)

  1. Status of the Double Chooz experiment

    Gonzalez, L.F.G. [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Dept. de Raios Cosmicos e Cronologia; Universite Oaris Diderot (France); Kemp, E. [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Dept. de Raios Cosmicos e Cronologia; Anjos, J.C. dos; Barbosa, A.F.; Lima Junior, H.P.; Gama, R.; Abrahao, T.; Pepe, I.M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Chimenti, P. [Universidade Federal do ABC (UFABC), SP (Brazil)

    2011-07-01

    Full text: The neutrino oscillation experiment Double Chooz, located at the nuclear power plant of Chooz (Ardennes, France), has as purpose to measure the mixing angle {theta}{sub 13} with greater precision than the measurement of its predecessor, the Chooz experiment. In four years of data acquisition, we expect to decrease the current limit of sin{sup 2}(2{theta}{sub 13}) from 0.2 to 0.03, contributing for the determination of this parameter that is still open in the neutrino mixing matrix. For this, the Double Chooz experiment will use antineutrinos generated in both Chooz plant reactors and will make high accuracy measurements of the flux in two different distances with identical detectors. The first detector (the 'far detector') is already in operation since January 2011 and the construction of the second one (the'{sup n}ear detector') should be completed on the beginning of 2012. Thus, in this work we present the main aspects of this neutrino oscillation experiment and preliminary results of the detector performance. (author)

  2. The U238 antineutrino spectrum in the Double Chooz experiment

    Haag, Nils; Oberauer, Lothar; Potzel, Walter; Schreckenbach, Klaus [Technische Universitaet, Muenchen (Germany); Lachenmaier, Tobias [Eberhard Karls Universitaet, Tuebingen (Germany)

    2011-07-01

    The DoubleChooz experiment aims at the determination of the unknown neutrino mixing parameter {Theta}{sub 13}. Two liquid scintillator detectors will measure an electron antineutrino disappearance at the Chooz site in the French ardennes. In order to improve the sensitivity, the antineutrino spectrum emitted by the Chooz reactor cores has to be determined with high accuracy. This talk focusses on the U238 spectrum, which is the only contributing spectrum, that was not measured until now. The final U238 beta spectrum is presented, and its implementation into the analysis framework is shown.

  3. Results from the Double Chooz experiment

    Kaneda Michiru

    2016-01-01

    Full Text Available Recent results from the Double Chooz experiment on the neutrino mixing angle θ13 are presented. Two detectors are located at distances of 400m and 1050m from the reactor cores of the Chooz nuclear power plant, to measure the original neutrino flux from the reactor cores and the disappearance of neutrinos, respectively. The Far Detector has taken data since 2011 while the Near Detector started the data taking in 2014. The latest far detector only result with gadolinium capture events is sin2 2θ13=0.090+0.032.-0.029. Studies using hydrogen capture events also have been improved and the combined result of gadolinium and hydrogen capture events is obtained as sin2 2θ13 = 0.088 ± 0.033.

  4. Neutrino oscillations - the Double Chooz experiment

    Lasserre, Th. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee (DSM/DAPNIA/SPP/APC), 91- Gif sur Yvette (France)

    2007-07-01

    {theta}{sub 13} is the mixing angle that couples the field of the neutrino number 3 (the heaviest) to the electron field. The Double Chooz experiment will use 2 identical detectors, near the Chooz nuclear reactor cores to measure the last undetermined mixing angle {theta}{sub 13}. The basic principle of the multi-detector concept is the cancellation of the reactor-induced systematic errors. The first detector will be installed in the existing underground laboratory (1050 meters away from the plant station) that was used in the first Chooz experiment in the nineties. The second detector will be constructed from 2009 in a new neutrino laboratory, located down a 45 m well that will be excavated 300 m away from the reactors. An average visible neutrino rate of 55 (550) events per day is expected to be detected inside the far (near) detector, taking into account the various inefficiencies, if no oscillations. The near detector will perform a measurement of the anti-neutrino flux and its energy spectrum with an unprecedented accuracy and for a long period (3 years). These huge statistics will also be exploited to monitor changes in the relative amounts of U{sup 235} and Pu{sup 239} in the core, paving the way to use neutrino detection for safeguards applications. (A.C.)

  5. Double-Chooz: a search for {theta}{sub 13}

    Lasserre, Th. [DSM/DAPNIA/SPP, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-12-15

    The Double-Chooz experiment goal is to search for a non-vanishing value of the {theta}{sub 13} neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin{sup 2}(2{theta}{sub 13})<0.2 (90% C.L., {delta}m{sub atm}{sup 2}=2.0eV{sup 2}). Double-Chooz will explore the range of sin{sup 2}(2{theta}{sub 13}) from 0.2 to 0.03-0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a ''state of the art'' prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sensitivity sin{sup 2}(2{theta}{sub 13}) of 0.05 in 2009, and 0.03-0.02 in 2011.

  6. Sterile neutrino search with the Double Chooz experiment

    Hellwig, Denise; Bekman, Ilja; Kampmann, Philipp; Schoppmann, Stefan; Soiron, Michael; Stahl, Achim; Wiebusch, Christopher [III. Physikalisches Institut B, RWTH Aachen (Germany)

    2016-07-01

    The Double Chooz experiment is a reactor neutrino disappearance experiment located at the Chooz nuclear power plant, France. It measures the electron-antineutrino flux of the two nuclear reactors with two detectors of identical design. A far detector at a distance of about 1 km is operating since 2011; a near detector at a distance of about 400 m is operating since the end of 2014. The combination of the two detectors offers sensitivity to sterile neutrino mixing parameters. Sterile neutrinos are neutrino mass states not taking part in weak interactions, but may mix with known neutrino states. This induces additional mixing angles and mass differences. This talk describes the search for sterile neutrinos and the sensitivity of Double Chooz to the mixing angle θ{sub 14}.

  7. Design studies for the Double Chooz trigger

    Cucoanes, Andi Sebastian

    2009-01-01

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles (θ 12 , θ 23 , θ 13 ) are describing the magnitude of this effect. Still unknown, θ 13 is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of ∝80% from the currently allowed θ 13 region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at ∝150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse β-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of them receiving signals from half of the photomultipliers. A third trigger board

  8. Design studies for the Double Chooz trigger

    Cucoanes, Andi Sebastian

    2009-07-24

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles ({theta}{sub 12}, {theta}{sub 23}, {theta}{sub 13}) are describing the magnitude of this effect. Still unknown, {theta}{sub 13} is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of {proportional_to}80% from the currently allowed {theta}{sub 13} region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at {proportional_to}150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse {beta}-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of

  9. Latest results from the Double Chooz experiment

    Goeger-Neff, Marianne [Physik Department E15, Technische Universitaet Muenchen (Germany); Collaboration: Double Chooz-Collaboration

    2016-07-01

    Double Chooz aims at a precise measurement of the neutrino mixing angle θ{sub 13} through the disappearance of reactor electron antineutrinos. The experiment relies on the measurement of neutrino flux and spectrum with two identical detectors at 400 m and 1000 m from the reactor cores of two nuclear power reactors. anti ν{sub e} are detected by inverse beta decay on free protons in 8.3 tons of Gd-loaded liquid scintillator, providing a unique delayed coincidence signature. Double Chooz has been running since 2011 with the far detector only, providing the first indication for non-zero θ{sub 13} with reactor antineutrinos. With a rate+shape analysis of 467.90 live days from 2011-2013 we obtain a value of sin {sup 2} 2 θ{sub 13}=0.090{sup +0.032}{sub -0.029}. Data taking with the near detector has started beginning of 2015, allowing a significant reduction of both reactor and detector related systematic uncertainties. The talk reviews the most recent results obtained with the far detector only and discuss first data from the near detector.

  10. Double-Chooz: a search for {theta}{sub 13}

    Mention, G. [APC/PCC, College de France, 75005 Paris (France)

    2005-08-15

    The Double-Chooz experiment goal is to search for a non-vanishing value of the {theta}{sub 13} neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin{sup 2}(2{theta}{sub 13}) < 0.2-0.14 (90% C.L., {delta}m{sub atm}{sup 2}=2.0-2.410{sup -3} eV{sup 2}). Double-Chooz will explore the range of sin{sup 2}(2{theta}{sub 13}) from 0.2 to 0.03-0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a 'state of the art' prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sin{sup 2}(2{theta}{sub 13}) sensitivity of 0.05 in 2009, and 0.03-0.02 in 2011.

  11. Chooz-A Steam Generators Characterization

    Aitammar, Laurie

    2016-01-01

    EDF nuclear waste management requires a deep understanding of characterization, classification and waste sorting operations. In fact, French nuclear waste management defines several classes with specific management, treatment and storage facilities. Based on particular criteria, the more the radiological risk of the nuclear waste is important, the more its management will be complex and expensive. During the dismantling of the first French pressurized reactor Chooz-A, decontamination of the primary water circuits (not including the reactor vessel), the steam generators and the pressurizer have been carried out in order to reduce their activity levels. Thanks to these decontamination operations, and a specific characterization methodology, EDF was able to Re-classify the 4 steam generators and store them in one piece at the ANDRA Very Low Level Activity disposal facilities instead of the Low and Intermediate Level activity one. This re-classification allowed EDF to avoid important cutting and packaging processes. To characterize and declare Chooz-A SG activity, EDF-CIDEN used a methodology defined by the French institute of atomic energy, CEA. The method is based on external gamma spectrometry measurements performed with NaI collimated detectors, associated with MERCURAD simulations providing the transfer functions for the detectors and activity sources. Internal measurements are carried out with a CZT (CdZnTe) probe inside the SG tubes to refine the 3D model. In fact, the primary side represents the main source of activity, and understanding its contamination distribution is important to reduce the model and calculation uncertainties. Measurements eventually provided SG 60 Co global activity, from which the activities of other radionuclides of the spectrum were determined using scaling factors. The final activity declaration takes into account the standard deviation of the measurements in order to cover the uncertainties of the methodology. Thereby, the declaration

  12. Background-independent measurement of θ13 in Double Chooz

    Abe, Y.; Anjos, J.C. dos; Barriere, J.C.; Baussan, E.; Bekman, I.; Bergevin, M.; Bezerra, T.J.C.; Bezrukov, L.; Blucher, E.; Buck, C.; Busenitz, J.; Cabrera, A.; Caden, E.; Camilleri, L.; Carr, R.; Cerrada, M.; Chang, P.-J.; Chauveau, E.

    2014-01-01

    The oscillation results published by the Double Chooz Collaboration in 2011 and 2012 rely on background models substantiated by reactor-on data. In this analysis, we present a background-model-independent measurement of the mixing angle θ 13 by including 7.53 days of reactor-off data. A global fit of the observed antineutrino rates for different reactor power conditions is performed, yielding a measurement of both θ 13 and the total background rate. The results on the mixing angle are improved significantly by including the reactor-off data in the fit, as it provides a direct measurement of the total background rate. This reactor rate modulation analysis considers antineutrino candidates with neutron captures on both Gd and H, whose combination yields sin 2 (2θ 13 )=0.102±0.028(stat.)±0.033(syst.). The results presented in this study are fully consistent with the ones already published by Double Chooz, achieving a competitive precision. They provide, for the first time, a determination of θ 13 that does not depend on a background model

  13. Chooz B1 start-up marked by total computer control

    Anon.

    1995-01-01

    The start-up of Chooz B1, the first of EdF's latest generation 1450 MWe N4 reactors, marks the first use in a nuclear power plant of a fully computerised control room. Working in partnership with EdF, Sema Group designed and supplied the advanced command and control system for this plant. (Author)

  14. The DoubleChooz DAQ systems.

    CERN. Geneva

    2012-01-01

    The Double Chooz (DC) reactor anti-neutrino experiment consists of a neutrino detector and a large area Outer Veto detector. A custom data-acquisition (DAQ) system written in Ada language for all the sub-detector in the neutrino detector systems and a generic object oriented data acquisition system for the Outer Veto detector were developed. Generic object-oriented programming was also used to support several electronic systems to be readout providing a simple interface for any new electronics to be added given its dedicated driver. The core electronics of the experiment is based on FADC electronics (500MHz sampling rate), therefore a data-reduction scheme has been implemented to reduce the data volume per trigger. A dynamic data-format was created to allow dynamic reduction of each trigger before data is written to disk. The decision is based on low level information that determines the relevance of each trigger. The DAQ is structured internally into two types of processors: several read-out processors readi...

  15. Progress in RPV-examination of the Chooz-A vessel (and the French procedures, its new developments (MIS5))

    Samman, J; Martin, E; Lacroix, R [Electricite de France (EDF), 93 - Saint-Denis (France). Groupe des Labs.

    1988-12-31

    This document deals with the French Chooz-A reactor. It describes the method used for in-service inspection of Reactor Pressure Vessels (RPV). The ultrasonic testing procedure is described, showing its advantages and limitations. The supplementary ultrasonic examination is also described, as well as the validation of underclad cracks detection and sizing. Historical data is also provided. (TEC).

  16. Nuclear safety and radiation protection report of the Chooz nuclear facilities - 2010; Rapport sur la surete nucleaire et la radioprotection des installations nucleaires de Chooz - 2010

    NONE

    2011-06-15

    This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chooz nuclear power plant (Ardennes (FR)): 2 PWR reactors in operation (Chooz B, INB 139 and 144) and one partially dismantled PWR reactor (Chooz A, INB 163). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

  17. Background estimation of cosmic-ray induced neutrons in Chooz site water veto tank for possible future Ricochet Deployment

    Silva, James

    2017-09-01

    The Ricochet experiment seeks to measure Coherent (neutral-current) Elastic Neutrino-Nucleus Scattering (CE νNS) using metallic superconducting and germanium semi-conducting detectors with sub-keV thresholds placed near a neutrino source such as the Chooz Nuclear Reactor Complex. In this poster, we present an estimate of the flux of cosmic-ray induced neutrons, which represent an important background in any (CE νNS) search, based on reconstructed cosmic ray data from the Chooz Site. We have simulated a possible Ricochet deployment at the Chooz site in GEANT4 focusing on the spallation neutrons generated when cosmic rays interact with the water tank veto that would surround our detector. We further simulate and discuss the effectiveness of various shielding configurations for optimizing the background levels for a future Ricochet deployment.

  18. The Chooz power station: ten years of operation

    Teste du Bailler, Andre

    1977-01-01

    The switching into actual service of the Chooz plant, the first pressurized water reactor ever built in France, occurred on 3rd april 1967. Ten years later, one can establish a highly positive balance schedule of plant's operation whose availability is satisfactory, except the mechanical failure which occurred during the startup. The behavior of the equipment, in particular of the components of the primary loop, was satisfactory in its whole since it allowed the gradual increase in capacity by 15% with respect to the initial design. It allowed also the achievment of noticeable progress in the design of equipment intended for the new power stations. Interesting results have also been obtained in radioprotection, working conditions of the staff and environment protection fields. Finally, the training of the operating teams has been closely followed, whether it concerned the operators directly affected by plant operation or the trainees gathered in a school specially organized for this purpose and transferred since to a training Center [fr

  19. Nuclear safety and radiation protection report of the Chooz nuclear facilities - 2011

    2012-01-01

    This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chooz nuclear power plant (Ardennes (FR)): 2 PWR reactors in operation (Chooz B, INB 139 and 144) and one partially dismantled PWR reactor (Chooz A, INB 163). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2011, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary followed by the viewpoint of the Committees for health, safety and working conditions. (J.S.)

  20. Nuclear safety and radiation protection report of the Chooz nuclear facilities - 2010

    2011-06-01

    This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chooz nuclear power plant (Ardennes (FR)): 2 PWR reactors in operation (Chooz B, INB 139 and 144) and one partially dismantled PWR reactor (Chooz A, INB 163). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

  1. The neutrino experiment Double Chooz and data analysis with the near detector

    Franke, Michael Werner

    2016-03-07

    During the last years there has been a huge progress in the field of neutrino physics. Neutrino oscillations are well established and almost all parameters, except a possible CP-violating phase, are determined to high precision. One experiment providing a precise measurement of the neutrino mixing angle θ{sub 13} is the Double Chooz reactor antineutrino experiment. The reactor antineutrinos are detected via the inverse beta decay in two identical liquid scintillator based detectors. A few years ago, the value of θ{sub 13} was unknown and only an upper limit existed. Double Chooz was the first reactor antineutrino experiment presenting a result for a nonzero value of θ{sub 13}. The value for sin{sup 2}2θ{sub 13} from the latest Double Chooz publication is 0.090{sup +0.032}{sub -0.029}. As part of this thesis, an infrastructure for filling the Double Chooz near detector was established and 190 m{sup 3} of detector liquids were prepared successfully. The filling process was optimized to allow an efficient filling of the near detector. The total operation time was reduced to only 22 days. Compared to the far detector filling time of 2 months, this is a great improvement. The development of a completely new level measurement system was as well part of this thesis. Due to the excellent performance of the level measurement system, the hard restrictions for the safety of the Double Chooz detector were met during the entire filling process. Several power glitches and network failures did not harm the system and did not result in any loss of data. These irregularities and the simple maintenance and repair possibilities certify the success of the design concept for the new level measurement system. For this thesis, data from the Double Chooz near detector with a total live time of 110.4 days was used. The mass concentrations of uranium and thorium in the near detector were determined using BiPo coincidences. These events originate from the β-decay of {sup 214}Bi and {sup

  2. Chasing theta-13 with the Double Chooz experiment

    Lasserre, Thierry [CEA/DSM/IRFU/SPP, Gif-sur-Yvette (France)

    2009-07-01

    Neutrino oscillation physics is entering a precision measurement area. The smallness of the theta-13 neutrino mixing angle is still enigmatic and should be resolved. Double Chooz will use two identical detectors near the Chooz nuclear power station to search for a non vanishing theta-13, and hopefully open the way to experiments aspiring to discover CP violation in the leptonic sector.

  3. Building a nuclear power plant from A to Z: Chooz B as an example

    Anon.

    1994-01-01

    From the design studies to the tests and reactor divergence, building a nuclear power plant involves strictly planned operations. This issue deals with the operations carried out first in the design offices and then on the site, in order to achieve such a vast and sophisticated industrial project: organizing, designing, engineering, assembling, testing, manufacturing and transporting heavy components. These various phases are shown through the example of Chooz B, a nuclear power plant with two 1.450 MW units, which is being built in the Ardennes, and whose first reactor will diverge in 1995. (author)

  4. From the measurement of the θ13 mixing angle to the search for geo-neutrinos: studying νe-bare with Double Chooz and Borexino

    Roncin, Romain

    2014-01-01

    Double Chooz is a reactor neutrino oscillation experiment which aims at measuring the θ 13 mixing angle thanks to two identical detectors located at different distances from the two reactors of the Chooz nuclear power plant, in the French Ardennes. While the near detector will start taking data in fall 2014 to normalize the flux of the neutrinos emitted by the nuclear reactors, the far detector is running since April 2011 and allows to observe the neutrinos disappearance through the neutrino oscillation phenomenon. This thesis is also dedicated to the Borexino experiment which was designed to observe solar neutrinos. Due to its low background level as well as its position in a nuclear free country, Italy, Borexino is also sensitive to geo-neutrinos. This thesis presents both the Double Chooz and Borexino experiments, from the description of the detectors to the main results, with a special attention to the background and its rejection. Studies on the neutrino directionality with these two experiments are also detailed. In the case of Double Chooz, since the neutrinos are coming from the two nuclear reactors, the precision of the analysis method can be assessed. This thesis presents also for the first time the possibility to retrieve the initial direction of the neutrinos when the neutrons created in the inverse beta decay reactions are captured on hydrogen. In the case of Borexino, neutrino directionality information could facilitate the discrimination between geo-neutrinos and neutrinos from nuclear reactors. (author) [fr

  5. CHOOZ-A expert assessment program

    Bouat, M.; Godin, R.

    1993-01-01

    CHOOZ-A Nuclear Power Plant, the first French-Belgian PWR unit (300 MWe) was definitively shut down at the end of October 1991, after 24 years in operation. Since summer 1991, the steering committee of the French (EDF) Lifetime Project has initiated a large inquiry to the different technical specialists of EDF and external organizations, trying to define a wide expert assessment program on this plant. The aim is to improve the knowledge of aging mechanisms such as those observed on the 52 PWR French nuclear power plants (900 and 1,300 MWe), and contribute to the validation of non-destructive in-service testing methods. This paper presents the retained CHOOZ-A expert assessment program and technical lines followed during its set up. First major project stages are described, then technical choices are explained, and at last the final program is presented with the specific content of each expert assessment. The definitive program is scheduled for a three year period starting at the moment of final shutdown license acquisition, with a provisional total budget of more than US $10 million

  6. Chooz nuclear facilities. 2009 annual report

    2010-01-01

    This annual report is established on account of article 21 of the 2006-686 French law from June 13, 2006, relative to the transparency and safety in the nuclear domain. It describes, first, the nuclear facilities of Chooz, and then the measures taken to ensure their safety (personnel radioprotection, actions implemented for nuclear safety improvement, organisation in crisis situation, external and internal controls, technical assessment of the facilities, administrative procedures carried out in 2009), incidents and accidents registered in 2009, radioactive and chemical effluents released by the facilities in the environment, other pollutions, management of radioactive wastes, and, finally, the actions carried out in the domain of transparency and public information. A glossary and the viewpoint of the Committee of Hygiene, safety and working conditions about the content of the document conclude the report. (J.S.)

  7. Development of a level-1 trigger and timing system for the Double Chooz neutrino experiment

    Reinhold, Bernd

    2009-01-01

    The measurement of the mixing angle θ 13 is the goal of several running and planned experiments. The experiments are either accelerator based (super)beam experiments (e.g. MINOS, T2K, Nova) or reactor anti-neutrino disappearance experiments (e.g. Daya Bay, RENO or Double Chooz). In order to measure or constrain θ 13 with the Double Chooz experiment the overall systematic errors have to be controlled at the one-percent or sub-percent level. The limitation of the systematic errors is achieved through various means and techniques. E.g. the experiment consists of two identical detectors at different baselines, which allow to make a differential anti-neutrino flux measurement, where basically only relative normalisation errors remain. The requirements on the systematic errors put also strong constraints on the quality of all components and materials used for both detectors, most prominently on the stability and radiopurity of the scintillator, the photomultiplier tubes, the vessels containing the detector liquids and the shielding against ambient radioactivity. The readout electronics, trigger and data acquisition system have to operate reliably as an integrated and highly efficient whole over several years. The trigger is provided by the Level-1 Trigger and Timing System, which is the subject of this thesis. It has to provide a highly efficient trigger (at the 0.1% level) for neutrino-induced events as well as for several types of background events. Its decision is realized in hardware and based on energy depositions in the muon veto and the target region. The Level-1 Trigger and Timing System furthermore provides a common System Clock and an absolute timestamp for each event. The Level-1 Trigger and Timing System consists of two types of VME modules, several Trigger Boards and a Trigger Master Board, which have been custom-designed and developed in the electronics workshop of our institute for this experiment and purpose, starting in 2005. In this thesis all

  8. Development of a level-1 trigger and timing system for the Double Chooz neutrino experiment

    Reinhold, Bernd

    2009-02-25

    The measurement of the mixing angle {theta}{sub 13} is the goal of several running and planned experiments. The experiments are either accelerator based (super)beam experiments (e.g. MINOS, T2K, Nova) or reactor anti-neutrino disappearance experiments (e.g. Daya Bay, RENO or Double Chooz). In order to measure or constrain {theta}{sub 13} with the Double Chooz experiment the overall systematic errors have to be controlled at the one-percent or sub-percent level. The limitation of the systematic errors is achieved through various means and techniques. E.g. the experiment consists of two identical detectors at different baselines, which allow to make a differential anti-neutrino flux measurement, where basically only relative normalisation errors remain. The requirements on the systematic errors put also strong constraints on the quality of all components and materials used for both detectors, most prominently on the stability and radiopurity of the scintillator, the photomultiplier tubes, the vessels containing the detector liquids and the shielding against ambient radioactivity. The readout electronics, trigger and data acquisition system have to operate reliably as an integrated and highly efficient whole over several years. The trigger is provided by the Level-1 Trigger and Timing System, which is the subject of this thesis. It has to provide a highly efficient trigger (at the 0.1% level) for neutrino-induced events as well as for several types of background events. Its decision is realized in hardware and based on energy depositions in the muon veto and the target region. The Level-1 Trigger and Timing System furthermore provides a common System Clock and an absolute timestamp for each event. The Level-1 Trigger and Timing System consists of two types of VME modules, several Trigger Boards and a Trigger Master Board, which have been custom-designed and developed in the electronics workshop of our institute for this experiment and purpose, starting in 2005. In

  9. Decree no. 96-927 from October 16, 1996 giving permission to Electricite de France to operate the Ardennes nuclear power plant including the basic nuclear installations no. 1 (reactor and auxiliary circuits), no. 2 (radioactive effluents processing plant) and no. 3 (fuel storage building), located on the territory of Chooz town (Ardennes)

    Borotra, F.

    1996-01-01

    This decree from the French ministry of industry and postal services gives to Electricite de France (EDF) the official permission to operate the Chooz nuclear power plant previously operated by the French-Belgium nuclear energy Society of the Ardennes. The operation will follow the conditions previously imposed to this Society. (J.S.)

  10. Computer-assisted command and control for Chooz B

    Anon.

    1995-01-01

    A new type of command and control system has been installed at the Chooz B nuclear power plant. A key feature of the system is a man/machine interface designed to provide operators with on-screen assistance more quickly than ever. (Author)

  11. Measuring the θ13 mixing angle with the two Double Chooz detectors

    Sibille, Valerian

    2016-01-01

    The Double Chooz experiment aims at accurately measuring the value of the θ 13 leptonic mixing angle. To this intent, the experiment makes the most of two identical detectors - filled with gadolinium-loaded liquid scintillator - observing ν e -bar's released by the two 4.25 GWth nuclear reactors of the French Chooz power plant. The so-called 'far detector' - located at an average distance of 1050 m from the two nuclear cores - has been taking data since April 2011. The 'near detector' - at an average distance of 400 m from the cores - has monitored the reactor since December 2014. The θ 13 mixing parameter leads to an energy dependent disappearance of ν e -bar's as they propagate from the nuclear cores to the detection sites, which allows for a fit of the sin 2 2θ 13 value. By reason of correlations between the detectors and an iso-flux layout, the detection systematics and the ν e -bar flux uncertainty impairing the θ 13 measurement are dramatically suppressed. In consequence, the precision of the θ 13 measurement is dominated by the uncertainty on the backgrounds and the relative normalisation of the ν e -bar-rates. The main background originates from the decay of β n -emitters - generated by μ-spallation - within the detector itself. The energy spectra of these cosmogenic isotopes have been simulated and complemented by a diligent error treatment. These predictions have been successfully compared to the corresponding data spectra, extracted by means of an active veto, whose performance has been studied at both sites. The rate of cosmogenic background remaining within the ν e -bar candidates has also been assessed. Additionally, the normalisation of the ν e -bar rates, bound to the number of target protons within each detector, has been evaluated. All this work was part of the first Double Chooz multi-detector results, yielding sin 2 2θ 13 =0.111 ± 0.018. (author) [fr

  12. Determination of the direction to a source of antineutrinos via inverse beta decay in Double Chooz

    Nikitenko, Ya.

    2016-11-01

    To determine the direction to a source of neutrinos (and antineutrinos) is an important problem for the physics of supernovae and of the Earth. The direction to a source of antineutrinos can be estimated through the reaction of inverse beta decay. We show that the reactor neutrino experiment Double Chooz has unique capabilities to study antineutrino signal from point-like sources. Contemporary experimental data on antineutrino directionality is given. A rigorous mathematical approach for neutrino direction studies has been developed. Exact expressions for the precision of the simple mean estimator of neutrinos' direction for normal and exponential distributions for a finite sample and for the limiting case of many events have been obtained.

  13. The chooz a expert survey program and its main conclusions for plant life management

    Barthelet, B.; Heuze, A.; Hennart, J.C.; Havard, P.

    2001-01-01

    Because of the importance of PWR components life management represents for Electricity Companies, significant R and D programs are dedicated to identifying and analysing mechanisms and damage rates of the different degradation modes of these components, systems and structures. To assess R and D assumptions and to validate non destructive test results through reviews, expert survey programs on in-situ equipment may enhance the knowledge about most of the various phenomena involved. In this regard, an extensive program was launched after the Chooz A NPP was decommissioned in 1991, after 24 years in operation. This program gathered EDF, IPSN, FRAMATOME, ELECTRABEL and TRACTEBEL into partnership. The expert survey program was performed in various laboratories between 1995 and 1999 and includes: - on-site non destructive testing before sampling, - and metallurgical and mechanical tests performed on samples taken from the nuclear and non nuclear part of the unit. The expert survey program performed by Utilities in various laboratories involved the following equipment: - reactor vessel and internal equipment, - reactor coolant system (dissimilar metal welds, SS welds, cast austenitic ferritic steels), - feedwater plant piping (erosion-corrosion), - electric cables susceptible of temperature and irradiation induced ageing, - anchoring in civil engineering structures, - main primary circuit concerning activation measurement. In conclusion, the extensive Chooz A expert survey program yields numerous significant results. The main outcomes will contribute to validate non destructive tests and enhance our knowledge of some degradation mechanisms of often quite similar components present in units in operation. It is worthy to note that this program is of prime importance for operation feedback; the cost of the whole study amounts to approximately 10 Million Euros. (author)

  14. Investigation of the Chooz-A nuclear power plant bolts

    Monnet, I.; Decroix, G.M.; Dubuisson, P.; Reuchet, J.; Morlent, O.

    2002-01-01

    In Pressurised Water Reactor, some baffle-former bolts in austenitic stainless steel, are submitted to an important Intergranular cracking. This cracking may be attributed to the irradiation hardening during in pile service. As part of its concern of safety related to the ageing of the plant and, in particular, to the behaviour of the internals, IRSN wished to take part in the expertise Program on CHOOZ A power nuclear plant, within the framework of a convention with EDF, which provided the baffle-bolts. Examinations of these bolts, after 140 000 of in pile service, were carried out by the laboratories of the CEA. Hardness profiles were carried out on four bolts, which were irradiated at different doses, ranging from 0 to 22 dpa. The bolt of the core barrel, considered as unirradiated, shows a constant value of hardness, equal to the value of unirradiated material, all along the bolt and a slight increase in the head of the screw. The axial profile of hardness carried out on an irradiated bolt shows that there is a gradient of hardness between the most irradiated part (400 Hv) and the least irradiated part (270 Hv). The hardness of this bolt starts to evolve at 2.5 dpa and the maximum of hardening is reached for the most irradiated part (3.6 dpa). The hardness profile on the most irradiated bolt (between 10 and 22 dpa) indicate that hardness is homogeneous all along the bolt, 400 Hv. It confirms the existence of a threshold dose beyond which hardness does not vary any more, this threshold is estimated to be between 3.6 dpa and 10 dl Microstructural examinations of these bolts led us to conclude that hardening is correlated to dislocation microstructure. Indeed, the examination of the bolt of the core barrel confirms that this bolt is hardly unirradiated since the initial network of dislocations was not modified and that only some rare dislocation loops were observed. This is in agreement with hardness results showing no hardening of this bolt. On the two more

  15. Installation, commissioning and performance of the trigger system of the Double Chooz experiment and the analysis of hydrogen capture neutrino events

    Lucht, Sebastian

    2013-11-18

    The Double Chooz experiment is a reactor antineutrino experiment located at Chooz, a small town in the Ardennes region in the north of France close to the Belgium border. The aim of the experiment is to measure the leptonic mixing angle θ{sub 13}. The antineutrino flux is measured by two identical detectors at different distances from the reactor cores used as neutrino source, in a so called ''disappearance'' experiment. Double Chooz is a precision experiment because previous experiments indicated a small value of θ{sub 13}. Therefore, the systematic uncertainties introduced by background events and detector related components have to be as small as possible. The detector and all electronic components have been designed accordingly. The first part of this thesis describes the trigger and timing system of the Double Chooz experiment. This system triggers the data acquisition of the detector. It continuously monitors the signals of the photomultiplier tubes (PMTs) of the detector. These signals are summed for groups of PMTs (group signal) and for all PMTs (sum signal). The group signals are the input signals to the trigger system. They are discriminated by one threshold resulting in a multiplicity condition on the number of active group signal discriminators. The sum signal is discriminated by four thresholds. The default trigger configuration for the Double Chooz experiment is based on a combination on the sum signal discriminators and the multiplicity condition. In addition, the trigger system provides a common clock signal for all data acquisition components and an online event classification to allow an online data reduction. The trigger system was installed and commissioned in 2011. In this thesis the commissioning of the trigger system and its performance is presented. Furthermore the development and tests of possible improvements for the trigger system are presented and discussed. The second part of this thesis introduces a complementary

  16. Characterization of Magnetic Field Immersed Photomultipliers from Double Chooz Experiment. Design and Construction of their Magnetic Shields; Caracterizacion de los fotomultiplicadores del experimento Double Chooz bajo campo magnetico y diseno y construccion de sus blindajes magneticos

    Valdivia Valero, F. J.

    2007-12-28

    Flavour oscillations of neutrinos are a quantum-mechanical effect widely demonstrated. It is explained through interferences of their mass eigenstates, therefore, belonging to the physical area beyond the Standard Model. This work deals with the CIEMAT collaboration in the neutrino experiment Double Chooz. Such an experiment aims to measure the mixture angle {theta}{sub 1}3, one of the PMNS leptonic mixture matrix, with a un reached-before sensibility by decrease of systematic errors. For this, two identical scintillator detectors, equipped with PMT's, will be sited at different distances from two reactors located in the nuclear power plant CHOOZ B (France). The electronic neutrino flux from these reactors will be compared, explaining its deficit by flavour oscillations of these particles. The identity of both detectors will be diminished by the magnetic field effects on the PMT's response. Therefore, this study serves as for quantifying such an effects as for fitting the magnetic shields design that minimize them. Shielding measurements and final design of magnetic shields as much as the effect these ones cause in the PMT's response immersed in a monitored magnetic field are presented. (Author) 85 refs.

  17. Characterization of Magnetic Field Immersed Photomultipliers from Double Chooz Experiment. Design and Construction of their Magnetic Shields; Caracterizacion de los fotomultiplicadores del experimento Double Chooz bajo campo magnetico y diseno y construccion de sus blindajes magneticos

    Valdivia Valero, F J

    2007-12-28

    Flavour oscillations of neutrinos are a quantum-mechanical effect widely demonstrated. It is explained through interferences of their mass eigenstates, therefore, belonging to the physical area beyond the Standard Model. This work deals with the CIEMAT collaboration in the neutrino experiment Double Chooz. Such an experiment aims to measure the mixture angle {theta}{sub 1}3, one of the PMNS leptonic mixture matrix, with a un reached-before sensibility by decrease of systematic errors. For this, two identical scintillator detectors, equipped with PMT's, will be sited at different distances from two reactors located in the nuclear power plant CHOOZ B (France). The electronic neutrino flux from these reactors will be compared, explaining its deficit by flavour oscillations of these particles. The identity of both detectors will be diminished by the magnetic field effects on the PMT's response. Therefore, this study serves as for quantifying such an effects as for fitting the magnetic shields design that minimize them. Shielding measurements and final design of magnetic shields as much as the effect these ones cause in the PMT's response immersed in a monitored magnetic field are presented. (Author) 85 refs.

  18. Studying the muon background component in the Double Chooz experiment

    Dietrich, Dennis

    2013-03-28

    The reactor anti-neutrino experiment Double Chooz (DC) will measure the third neutrino mixing angle θ{sub 13} with very high precision. This mixing angle is connected to fundamental questions in particle physics beyond the current Standard Model. In DC neutrinos are detected via the Inverse Beta Decay reaction, which provides a clean signal distinguishable from most backgrounds. However, as neutrino interactions in the detector are very rare and an interfering muon background is present, a proper understanding and reduction of this background is mandatory. This is crucial because muons create fast neutrons and βn-emitters which lead to background capable of mimicking the neutrino interaction in the detector. This thesis covers different analysis topics related to the cosmic ray muon background at the DC far site. The thesis covers the identification of muons, the applied rejection technique and the determination of the muon rate at DC far site. Utilizing the muon rejection cuts of the neutrino analysis a muon rate of 13 s{sup -1} in the Inner Detector (ID) and of 46 s{sup -1} in the Inner Muon Veto (IV) was found. The efficiency of the IV to identify and reject cosmic ray muons was measured and a value greater than 99.97% has been found. The stability of the determined muon rates was examined and a seasonal modulation was found, compatible with a variation of the temperature profile of the atmosphere over the year. The parameter describing the strength between the relationship of temperature and muon rate change, the effective temperature coefficient was obtained: αT=0.39±0.01(stat.)±0.02(syst.). This gave the opportunity to measure the atmospheric kaon to pion ratio with the DC far detector which was found to be r(K/π)=0.14±0.06. Additional variations of muon rate with surface pressure were found and the barometric coefficient describing this effect was measured as βp=-0.59±0.20(stat.)±0.10(syst.) permille /mbar. Another central theme of this work was

  19. Studying the muon background component in the Double Chooz experiment

    Dietrich, Dennis

    2013-01-01

    The reactor anti-neutrino experiment Double Chooz (DC) will measure the third neutrino mixing angle θ 13 with very high precision. This mixing angle is connected to fundamental questions in particle physics beyond the current Standard Model. In DC neutrinos are detected via the Inverse Beta Decay reaction, which provides a clean signal distinguishable from most backgrounds. However, as neutrino interactions in the detector are very rare and an interfering muon background is present, a proper understanding and reduction of this background is mandatory. This is crucial because muons create fast neutrons and βn-emitters which lead to background capable of mimicking the neutrino interaction in the detector. This thesis covers different analysis topics related to the cosmic ray muon background at the DC far site. The thesis covers the identification of muons, the applied rejection technique and the determination of the muon rate at DC far site. Utilizing the muon rejection cuts of the neutrino analysis a muon rate of 13 s -1 in the Inner Detector (ID) and of 46 s -1 in the Inner Muon Veto (IV) was found. The efficiency of the IV to identify and reject cosmic ray muons was measured and a value greater than 99.97% has been found. The stability of the determined muon rates was examined and a seasonal modulation was found, compatible with a variation of the temperature profile of the atmosphere over the year. The parameter describing the strength between the relationship of temperature and muon rate change, the effective temperature coefficient was obtained: αT=0.39±0.01(stat.)±0.02(syst.). This gave the opportunity to measure the atmospheric kaon to pion ratio with the DC far detector which was found to be r(K/π)=0.14±0.06. Additional variations of muon rate with surface pressure were found and the barometric coefficient describing this effect was measured as βp=-0.59±0.20(stat.)±0.10(syst.) permille /mbar. Another central theme of this work was the extrapolation

  20. Characterization of Magnetic Field Immersed Photomultipliers from Double Chooz Experiment. Design and Construction of their Magnetic Shields

    Valdivia Valero, F. J.

    2007-01-01

    Flavour oscillations of neutrinos are a quantum-mechanical effect widely demonstrated. It is explained through interferences of their mass eigenstates, therefore, belonging to the physical area beyond the Standard Model. This work deals with the CIEMAT collaboration in the neutrino experiment Double Chooz. Such an experiment aims to measure the mixture angle θ 1 3, one of the PMNS leptonic mixture matrix, with a un reached-before sensibility by decrease of systematic errors. For this, two identical scintillator detectors, equipped with PMT's, will be sited at different distances from two reactors located in the nuclear power plant CHOOZ B (France). The electronic neutrino flux from these reactors will be compared, explaining its deficit by flavour oscillations of these particles. The identity of both detectors will be diminished by the magnetic field effects on the PMT's response. Therefore, this study serves as for quantifying such an effects as for fitting the magnetic shields design that minimize them. Shielding measurements and final design of magnetic shields as much as the effect these ones cause in the PMT's response immersed in a monitored magnetic field are presented. (Author) 85 refs

  1. Electromagnetic Compatibility (EMC) and Noise Background Testing for Double Chooz PMT System

    Cepero, J. R.; Encabo Fernandez, F. J.; Pepe, I.; Verdugo, A.

    2009-05-21

    The Double Chooz PMT system is a HV/signal splitter. In this report is presented an electromagnetic compatibility and background noise testing for the Double Chooz PMT system. It was possible to proceed the EMC testing on different grounding configurations of PMT splitter due to its special PCB design, endowed of jumping points and a metal box ground electrode. (Author)

  2. Electromagnetic Compatibility (EMC) and Noise Background Testing for Double Chooz PMT System

    Cepero, J. R.; Encabo Fernandez, F. J.; Pepe, I.; Verdugo, A.

    2009-01-01

    The Double Chooz PMT system is a HV/signal splitter. In this report is presented an electromagnetic compatibility and background noise testing for the Double Chooz PMT system. It was possible to proceed the EMC testing on different grounding configurations of PMT splitter due to its special PCB design, endowed of jumping points and a metal box ground electrode. (Author)

  3. Utilization of FADC for reconstruction and analysis of the background data in the Chooz neutrino experiment

    Veron, Didier

    1997-01-01

    This thesis describes a particular contribution to the Chooz experiment. The latter looks for the oscillations, over a distance of 1 km, of antineutrons emitted by two nuclear reactors. The electron-type antineutrinos are detected through their inverse beta interaction with a target's proton. The neutron is detected through its capture by a gadolinium nucleus revealed by an 8 MeV gamma emission. In the first part we describe the reconstruction of events as simulated by the GIANT software. We show that the positron's and neutron's stopping point can actually be reconstructed with an accuracy of 10 and 20 cm respectively. In the second part, we proceed to the analysis of the calibration's data as recorded with Fast Wave Form Digitizers. This confirms the reliability of the Monte-Carlo results and allows measurement of both the neutrons' capture probability and time by the target gadolinium. The last part deals with the background (reactor turned off) data analysis and the pin-pointing of its various sources. In order to reduce their contribution, we define spatial cuts. These cuts' reliability is validated by analysis of data obtained not only with a neutron source, but also with neutrons issued from cosmic rays. We end up with a background contribution of two to three events per day, about ten times less than the expected neutrino rate at full reactor power. (author)

  4. 3D - Acquisition systems - test in Chooz B nuclear plant

    Brillault, B.; Thibault, G.

    1992-06-01

    EDF needs 3D-acquisition systems to get the precise geometry of critical nuclear spaces in order to prepare computer simulations of operations in these areas. The simulations must lead to an increase of the efficiency of the operation. The acquisition of the 3-D geometry can be done using 3D-acquisition systems. To answer the needs of the Construction Division, four different systems are compared by the Research Division in Chooz B nuclear plant in order to determine the right solution for each 3D-acquisition problem

  5. Double Chooz and non Asian efforts towards {theta}{sub 13}

    Lasserre, Thierry [CEA/Saclay and Laboratoire Astroparticle and Cosmologie Institut de Recherche des Lois Fondamentales de l' Univers Service de Physique des Particules 91191 Gif-s-Yvette (France)], E-mail: thierry.lasserre@cea.fr

    2008-11-01

    Neutrino oscillation physics is entering a precision measurement area. The smallness of the {theta}{sub 13} neutrino mixing angle is still enigmatic and should be resolved. Double Chooz will use two identical detectors near the Chooz nuclear power station to search for a non vanishing {theta}{sub 13}, and hopefully open the way to experiments aspiring to discover CP violation in the leptonic sector. The Angra project aims to prevail over the Double Chooz experiment if the third neutrino oscillation channel is not discovered in the forthcoming years.

  6. Estimation of the systematic uncertainties of the measurement of the neutrino mixing angle θ{sub 13} related to the trigger system of the Double Chooz experiment

    Stueken, David Anselm

    2013-10-14

    The Double Chooz experiment, located in the Ardennes region next to the CHOOZ-B nuclear power plant, is a reactor antineutrino experiment to measure neutrino oscillations. It has been designed as precision experiment to measure the neutrino mixing angel θ{sub 13} with highest possible accuracy due to its small value close to zero. The electron antineutrino flux emitted by the reactor cores is measured by two identical neutrino detectors located at different distances from the reactor cores. Each detector consist of a 10.3 m{sup 3} target volume filled with liquid scintillator and surrounded by 390 photomultiplier tubes. The far detector is located 1.05 km away from the reactor cores to be most sensitive to oscillation effects. The unoscillated neutrino flux is measured by the near detector located 400 m away from the reactor cores. In order to reduce background events and other sources resulting in systematic uncertainties, special requirements have been demanded for all detector components and electronic systems. In this context, a most efficiently operating data acquisition system is essential. The subsystem responsible to start data storage for events of interest is the so called ''trigger system''. The design concept of the Double Chooz trigger system introduces two redundancy concepts in order to trigger the data acquisition in the most robust and efficient way: The trigger decision is based on a combination of an energy threshold and the number of active photomultiplier tubes (multiplicity condition). Secondly, the system is divided into two identical but independently operating subsystems for most robust operations of the full system. Additionally, the two subsystem provide the possibility to measure the efficiency of the system. Apart from generating the trigger signal for the data acquisition, the system provides an online event classification in order to adjust the amount of stored data for each event type. After one and a half year

  7. Light Production in the Double Chooz Photomultiplier Tubes

    Calvo, E.; Cerrada, M.; Crespo, J. I.; Gil-Botella, I.; Jimenez, S.; Lopez, M.; Novella, P.; Palomares, C.; Santorelli, R.; Verdugo, A.

    2012-09-13

    In this document we present a study of the phenomenon of light emission (called glowing) in the bases of the Hamamatsu R7081MOD-ASSY photomultiplier tubes (PMTs) used in the Double Chooz experiment. The tests have been carried out at the CIEMAT laboratories over a photomultiplier tube of the same model. We have studied the phenomenon making first a characterization of it, and then focusing on the dependence of the rate and the amount of emitted light versus voltage and temperature. In addition, we have looked for the possible existence of an ultraviolet component in the light which would be harmful for the experiment because it could be able to excite the scintillator liquid. Finally, we propose and test a method to reduce the light emission using a cover on the base of the photomultiplier tube.. (Author)

  8. Safety margins of PWR irradiated vessels - The Chooz A issue

    Hedin, F; Barthelet, B [Electricite de France (EDF), 75 - Paris (France); Guilleret, J C

    1988-12-31

    In 1986, some irradiated specimen of CHOOZ A (SENA) vessel showed a significant excess of {delta} RTNDT to former previsions. The lack of data on one of the two irradiated shells, and discrepancies between dosimeters results and available previous fluence calculations whose accuracy was questionable, cause the safety authorities to require an important complementary work program before putting again the plant on the grid after 1987 fuel reloading. These works are presented and discussed. They lead to a state that a conservative to day value of the vessel RTNDT is 64 degrees Celsius and that there is no underclad defect in the vessel wall and welds. Then the plant was allowed to restart with certitude that vessel irradiation will not impair its lifetime. (author). 4 refs.

  9. Measurement of θ_1_3 in Double Chooz using neutron captures on hydrogen with novel background rejection techniques

    Abe, Y.; Appel, S.; Abrahão, T.; Almazan, H.

    2016-01-01

    The Double Chooz collaboration presents a measurement of the neutrino mixing angle θ_1_3 using reactor ν̄_e observed via the inverse beta decay reaction in which the neutron is captured on hydrogen. This measurement is based on 462.72 live days data, approximately twice as much data as in the previous such analysis, collected with a detector positioned at an average distance of 1050 m from two reactor cores. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties. Accidental coincidences, the dominant background in this analysis, are suppressed by more than an order of magnitude with respect to our previous publication by a multi-variate analysis. These improvements demonstrate the capability of precise measurement of reactor ν̄_e without gadolinium loading. Spectral distortions from the ν̄_e reactor flux predictions previously reported with the neutron capture on gadolinium events are confirmed in the independent data sample presented here. A value of sin"2 2θ_1_3=0.095_−_0_._0_3_9"+"0"."0"3"8(stat+syst) is obtained from a fit to the observed event rate as a function of the reactor power, a method insensitive to the energy spectrum shape. A simultaneous fit of the hydrogen capture events and of the gadolinium capture events yields a measurement of sin"2 2θ_1_3=0.088±0.033(stat+syst).

  10. Fast reactor development program in France in 1997

    Langrand, J.C.; Hubert, G.; Marmonier, P.; Del Negro, R.; Saint-Arroman, G.; Coulon, P.; Mesnage, B.; Pillon, S.; Lefevre, J.C.

    1998-01-01

    The operating performance of the French nuclear plants in 1997 were again satisfactory, confirming the good 1996 results; 78% of the national electricity production was of nuclear origin (376/481 TWh); the nuclear safety indicators were even better with a slight decrease in the number of reported incidents; the availability factor was higher than 82,5%; the kWh production cost continue to decrease by about 1,7% per year; thanks to an ALARA approach, individual and collective doses are still decreasing; the liquid and gaseous releases are also still decreasing and the volume of nuclear wastes is equivalent to last year. The major event of 1997 was the confirmation for the start up of the most advanced nuclear plants, N4 type, with Chooz B1 reaching full power on May 9, 1997 and Chooz B2 following soon with first criticality on March 10 and full power on September 18. As a confirmation and enjoying the experience of Chooz B the first unit of Civaux was synchronised to the grid end of 1997 after fuel loading in Sept 1997. The status of fast reactors was deeply modified, with the governmental decision to abandon Superphenix, which led to decide to close also EFR studies in 1997, and the perspective of operating Phenix till 2004, mainly for studies on radioactive wastes incineration. Three meetings were held during the second half of the year by the > (GP - Permanent Committee) on Phenix; after reviewing all the safety aspects, they concluded to the possibility to resume operation according to the general following scheme: one cycle in 1998, about one year for works, then 6 cycles between 2000 and 2004. Of course, the main event concerning Superphenix is the decision of abandon announced in June 1997. The decree allowing operation had been cancelled in February. The works foreseen in the frame of the planned > shutdown had been conducted satisfactorily, during the first-half of the year. At the beginning of 1998, it was stated that the reactor would not operate again

  11. Utilization of FADC for reconstruction and analysis of the background data in the Chooz neutrino experiment; Utilisation des FADC pour la reconstruction et l`analyse des donnees de bruit de fond dans l`experience neutrino de Chooz

    Veron, Didier [Universite Claude Bernard, 69 - Lyon (France)

    1997-03-25

    This thesis describes a particular contribution to the Chooz experiment. The latter looks for the oscillations, over a distance of 1 km, of antineutrons emitted by two nuclear reactors. The electron-type antineutrinos are detected through their inverse beta interaction with a target`s proton. The neutron is detected through its capture by a gadolinium nucleus revealed by an 8 MeV gamma emission. In the first part we describe the reconstruction of events as simulated by the GIANT software. We show that the positron`s and neutron`s stopping point can actually be reconstructed with an accuracy of 10 and 20 cm respectively. In the second part, we proceed to the analysis of the calibration`s data as recorded with Fast Wave Form Digitizers. This confirms the reliability of the Monte-Carlo results and allows measurement of both the neutrons` capture probability and time by the target gadolinium. The last part deals with the background (reactor turned off) data analysis and the pin-pointing of its various sources. In order to reduce their contribution, we define spatial cuts. These cuts` reliability is validated by analysis of data obtained not only with a neutron source, but also with neutrons issued from cosmic rays. We end up with a background contribution of two to three events per day, about ten times less than the expected neutrino rate at full reactor power. (author) 81 refs., 152 figs.,43 tabs.

  12. Realization of the low background neutrino detector Double Chooz. From the development of a high-purity liquid and gas handling concept to first neutrino data

    Pfahler, Patrick

    2012-12-17

    Neutrino physics is one of the most vivid fields in particle physics. Within this field, neutrino oscillations are of special interest as they allow to determine driving oscillation parameters, which are collected as mixing angles in the leptonic mixing matrix. The exact knowledge of these parameters is the main key for the investigation of new physics beyond the currently known Standard Model of particle physics. The Double Chooz experiment is one of three reactor disappearance experiments currently taking data, which recently succeeded to discover a non-zero value for the last neutrino mixing angle {Theta}{sub 13}. As successor of the CHOOZ experiment, Double Chooz will use two detectors with improved design, each of them now composed of four concentrically nested detector vessels each filled with different detector liquid. The integrity of this multi-layered structure and the quality of the used detector liquids are essential for the success of the experiment. Within this frame, the here presented work describes the production of two detector liquids, the filling and handling of the Double Chooz far detector and the installation of all necessary hardware components therefore. In order to meet the strict requirements existing for the detector liquids, all components were individually selected in an extensive material selection process at TUM, which compared samples from different companies for their key properties: density, transparency, light yield and radio purity. Based on these measurements, the composition of muon veto scintillator and buffer liquid were determined. For the production of the detector liquids, a simple surface building close to the far detector site was upgraded into a large-scale storage and mixing facility, which allowed to separately, mix, handle and store 90 m{sup 3} of muon veto scintillator and 110 m{sup 3} of buffer liquid. For the muon veto scintillator, a master-solution composed of 4800 l LAB, 180 kg PPO and 1.8 kg of bis/MSB was

  13. Realization of the low background neutrino detector Double Chooz. From the development of a high-purity liquid and gas handling concept to first neutrino data

    Pfahler, Patrick

    2012-01-01

    Neutrino physics is one of the most vivid fields in particle physics. Within this field, neutrino oscillations are of special interest as they allow to determine driving oscillation parameters, which are collected as mixing angles in the leptonic mixing matrix. The exact knowledge of these parameters is the main key for the investigation of new physics beyond the currently known Standard Model of particle physics. The Double Chooz experiment is one of three reactor disappearance experiments currently taking data, which recently succeeded to discover a non-zero value for the last neutrino mixing angle Θ 13 . As successor of the CHOOZ experiment, Double Chooz will use two detectors with improved design, each of them now composed of four concentrically nested detector vessels each filled with different detector liquid. The integrity of this multi-layered structure and the quality of the used detector liquids are essential for the success of the experiment. Within this frame, the here presented work describes the production of two detector liquids, the filling and handling of the Double Chooz far detector and the installation of all necessary hardware components therefore. In order to meet the strict requirements existing for the detector liquids, all components were individually selected in an extensive material selection process at TUM, which compared samples from different companies for their key properties: density, transparency, light yield and radio purity. Based on these measurements, the composition of muon veto scintillator and buffer liquid were determined. For the production of the detector liquids, a simple surface building close to the far detector site was upgraded into a large-scale storage and mixing facility, which allowed to separately, mix, handle and store 90 m 3 of muon veto scintillator and 110 m 3 of buffer liquid. For the muon veto scintillator, a master-solution composed of 4800 l LAB, 180 kg PPO and 1.8 kg of bis/MSB was produced and

  14. Boron neutron capture therapy (BNCT) translational studies in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration of the RA-6 nuclear reactor

    Monti Hughes, Andrea; Trivillin, Veronica A.; Schwint, Amanda E. [Constituyentes Atomic Center, National Atomic Energy Commission (CNEA), Department of Radiobiology, San Martin, Province Buenos Aires (Argentina); National Research Council (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Longhino, Juan; Boggio, Esteban [Bariloche Atomic Center, CNEA, Department of Nuclear Engineering, San Carlos de Bariloche, Province Rio Negro (Argentina); Medina, Vanina A.; Martinel Lamas, Diego J. [National Research Council (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Pontifical Catholic University of Argentina (UCA), Laboratory of Tumoral Biology and Inflammation, School of Medical Sciences, Institute for Biomedical Research (BIOMED CONICET-UCA), Ciudad Autonoma de Buenos Aires (Argentina); Garabalino, Marcela A.; Heber, Elisa M.; Pozzi, Emiliano C.C. [Constituyentes Atomic Center, National Atomic Energy Commission (CNEA), Department of Radiobiology, San Martin, Province Buenos Aires (Argentina); Itoiz, Maria E. [Constituyentes Atomic Center, National Atomic Energy Commission (CNEA), Department of Radiobiology, San Martin, Province Buenos Aires (Argentina); UBA, Department of Oral Pathology, Faculty of Dentistry, Ciudad Autonoma de Buenos Aires (Argentina); Aromando, Romina F. [UBA, Department of Oral Pathology, Faculty of Dentistry, Ciudad Autonoma de Buenos Aires (Argentina); Nigg, David W. [Idaho National Laboratory, Idaho Falls (United States)

    2017-11-15

    Boron neutron capture therapy (BNCT) is based on selective accumulation of B-10 carriers in tumor followed by neutron irradiation. We demonstrated, in 2001, the therapeutic effect of BNCT mediated by BPA (boronophenylalanine) in the hamster cheek pouch model of oral cancer, at the RA-6 nuclear reactor. Between 2007 and 2011, the RA-6 was upgraded, leading to an improvement in the performance of the BNCT beam (B2 configuration). Our aim was to evaluate BPA-BNCT radiotoxicity and tumor control in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration. We also evaluated, for the first time in the oral cancer model, the radioprotective effect of histamine against mucositis in precancerous tissue as the dose-limiting tissue. Cancerized pouches were exposed to: BPA-BNCT; BPA-BNCT + histamine; BO: Beam only; BO + histamine; CONTROL: cancerized, no-treatment. BNCT induced severe mucositis, with an incidence that was slightly higher than in ''B1'' experiments (86 vs 67%, respectively). BO induced low/moderate mucositis. Histamine slightly reduced the incidence of severe mucositis induced by BPA-BNCT (75 vs 86%) and prevented mucositis altogether in BO animals. Tumor overall response was significantly higher in BNCT (94-96%) than in control (16%) and BO groups (9-38%), and did not differ significantly from the ''B1'' results (91%). Histamine did not compromise BNCT therapeutic efficacy. BNCT radiotoxicity and therapeutic effect at the B1 and B2 configurations of RA-6 were consistent. Histamine slightly reduced mucositis in precancerous tissue even in this overly aggressive oral cancer model, without compromising tumor control. (orig.)

  15. Boron neutron capture therapy (BNCT) translational studies in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration of the RA-6 nuclear reactor

    Monti Hughes, Andrea; Trivillin, Veronica A.; Schwint, Amanda E.; Longhino, Juan; Boggio, Esteban; Medina, Vanina A.; Martinel Lamas, Diego J.; Garabalino, Marcela A.; Heber, Elisa M.; Pozzi, Emiliano C.C.; Itoiz, Maria E.; Aromando, Romina F.; Nigg, David W.

    2017-01-01

    Boron neutron capture therapy (BNCT) is based on selective accumulation of B-10 carriers in tumor followed by neutron irradiation. We demonstrated, in 2001, the therapeutic effect of BNCT mediated by BPA (boronophenylalanine) in the hamster cheek pouch model of oral cancer, at the RA-6 nuclear reactor. Between 2007 and 2011, the RA-6 was upgraded, leading to an improvement in the performance of the BNCT beam (B2 configuration). Our aim was to evaluate BPA-BNCT radiotoxicity and tumor control in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration. We also evaluated, for the first time in the oral cancer model, the radioprotective effect of histamine against mucositis in precancerous tissue as the dose-limiting tissue. Cancerized pouches were exposed to: BPA-BNCT; BPA-BNCT + histamine; BO: Beam only; BO + histamine; CONTROL: cancerized, no-treatment. BNCT induced severe mucositis, with an incidence that was slightly higher than in ''B1'' experiments (86 vs 67%, respectively). BO induced low/moderate mucositis. Histamine slightly reduced the incidence of severe mucositis induced by BPA-BNCT (75 vs 86%) and prevented mucositis altogether in BO animals. Tumor overall response was significantly higher in BNCT (94-96%) than in control (16%) and BO groups (9-38%), and did not differ significantly from the ''B1'' results (91%). Histamine did not compromise BNCT therapeutic efficacy. BNCT radiotoxicity and therapeutic effect at the B1 and B2 configurations of RA-6 were consistent. Histamine slightly reduced mucositis in precancerous tissue even in this overly aggressive oral cancer model, without compromising tumor control. (orig.)

  16. Muon background studies for shallow depth Double - Chooz near detector

    Gómez, H. [Laboratoire Astroparticule et Cosmologie (APC) - Université Paris 7. Paris (France)

    2015-08-17

    Muon events are one of the main concerns regarding background in neutrino experiments. The placement of experimental set-ups in deep underground facilities reduce considerably their impact on the research of the expected signals. But in the cases where the detector is installed on surface or at shallow depth, muon flux remains high, being necessary their precise identification for further rejection. Total flux, mean energy or angular distributions are some of the parameters that can help to characterize the muons. Empirically, the muon rate can be measured in an experiment by a number of methods. Nevertheless, the capability to determine the muons angular distribution strongly depends on the detector features, while the measurement of the muon energy is quite difficult. Also considering that on-site measurements can not be extrapolated to other sites due to the difference on the overburden and its profile, it is necessary to find an adequate solution to perform the muon characterization. The method described in this work to obtain the main features of the muons reaching the experimental set-up, is based on the muon transport simulation by the MUSIC software, combined with a dedicated sampling algorithm for shallow depth installations based on a modified Gaisser parametrization. This method provides all the required information about the muons for any shallow depth installation if the corresponding overburden profile is implemented. In this work, the method has been applied for the recently commissioned Double - Chooz near detector, which will allow the cross-check between the simulation and the experimental data, as it has been done for the far detector.

  17. Muon background studies for shallow depth Double - Chooz near detector

    Gómez, H.

    2015-01-01

    Muon events are one of the main concerns regarding background in neutrino experiments. The placement of experimental set-ups in deep underground facilities reduce considerably their impact on the research of the expected signals. But in the cases where the detector is installed on surface or at shallow depth, muon flux remains high, being necessary their precise identification for further rejection. Total flux, mean energy or angular distributions are some of the parameters that can help to characterize the muons. Empirically, the muon rate can be measured in an experiment by a number of methods. Nevertheless, the capability to determine the muons angular distribution strongly depends on the detector features, while the measurement of the muon energy is quite difficult. Also considering that on-site measurements can not be extrapolated to other sites due to the difference on the overburden and its profile, it is necessary to find an adequate solution to perform the muon characterization. The method described in this work to obtain the main features of the muons reaching the experimental set-up, is based on the muon transport simulation by the MUSIC software, combined with a dedicated sampling algorithm for shallow depth installations based on a modified Gaisser parametrization. This method provides all the required information about the muons for any shallow depth installation if the corresponding overburden profile is implemented. In this work, the method has been applied for the recently commissioned Double - Chooz near detector, which will allow the cross-check between the simulation and the experimental data, as it has been done for the far detector

  18. In-service - pressure test of the primary circuit of the Chooz nuclear power plant

    Barthelemy, F.L.; Lespiaucq, P.G.

    1977-01-01

    A brief summary is given of the regulations governing inspection pratices of operating nuclear power plants, in France. As an example, such an inspection performed in 1976 on the Westinghouse 320 MWe PWR built in Chooz (Ardennes) is described. Emphasis is put on the administrative organization, the technical solutions, the specific problems and the difficulties encountered. (author)

  19. Double Chooz sensitivity and backgrounds studies to search for θ13 leptonic mixing angle

    Mention, G.

    2005-06-01

    The Double Chooz experiment will study the oscillations of electron antineutrinos produced by the Chooz nuclear power station to measure θ 13 mixing angle. The current knowledge on this parameter, provided ny the Chooz experiment, can be improved by reducing statistical and systematic errors. A large data sample will be collected to improve the former one. Two identical detectors will be built to cancel most of experimental systematic uncertainties involved in production and detection processes. Special care will be dedicated to backgrounds generated by natural radioactivity and cosmic ray interactions. In the hereby thesis, we describe our simulation studies to compute θ 13 sensitivity and assess the discovery potential of the experiment. We concentrated particularly on quantifying the detector related systematic errors that would limit the θ 13 sensitivity. Background related systematic errors such as the accidental events produced by the radioactivity of the photomultiplier tubes, correlated events from neutrons as well as a hypothetical background (mimicking the oscillation pattern) were taken into account. After 3 years, Double Chooz will be able to disentangle an oscillation signal for sin 2 (2*θ 13 ) > 0.05 (at 3*σ) or, if no oscillations were observed, to put a limit of sin 2 (2θ 13 ) < 0.03 at 90% C.L. (author)

  20. Correlated background and impact on the measurement of θ13 with the Double Chooz detector

    Remoto, Alberto

    2012-01-01

    The Double Chooz experiment uses antineutrinos emitted from the Chooz nuclear power plant (France) to measure the oscillation mixing parameter θ 13 . By using two detectors at different baselines, a precise measurement of antineutrinos disappearance is anticipated. The Far detector has been taking physics data since April 2011, while the Near detector is under construction. Data from April 13, 2011 to March 30, 2012 taken with the Far detector only have been analyzed and an indication for antineutrino disappearance, consistent with the current neutrino oscillation hypothesis, has been found. The best fit value for the neutrino mixing parameter sin 2 (2θ 13 ) is 0.109 ± 0.030(stat.) ± 0.025(syst.). This thesis present an accurate description of the Double Chooz experiment, with particular emphasis on the Far detector and its acquisition system. The main focus of the thesis is the accurate study of the correlated background affecting the Double Chooz antineutrinos sample and its impact on the measurement of the mixing parameter θ 13 . A general overview of the current experimental scenario which aim to the characterization of the neutrino oscillation is also provided, focusing on the recent results obtained in this field. (author) [fr

  1. Flash-ADCs test, optimization of the detector design and development of a new concept of spatial reconstruction in the double chooz neutrino oscillation experiment

    Akiri, T.

    2010-09-01

    Double Chooz (DC) is a reactor neutrino oscillation experiment whose purpose is the measurement of the last unknown mixing angle θ 13 . It inherits from the past Chooz experiment which was limited by the statistical and systematic errors at the same extent of about 2.8%. To lower the statistical error, the DC detector target mass has been increased and a longer exposure is foreseen while the lowering of the systematic error is ensured by the use of two identical detectors. One will be located in the vicinity of the reactor cores to monitor the flux and spectrum of the ν-bar e emitted whereas the other one will be located where the effect of the oscillation is expected to be maximal. They are respectively so-called 'near' and 'far' detectors. The expected errors are 0.5% (stat.) and 0.6% (syst.) for a measurement down to sin 2 (2*θ 13 ) = 0.05 (θ 13 6.5 degrees) at three standard deviations after three years of data taking. The far detector is expected for November 2010 while the near detector will be operational in mid-2012. This thesis presents first a hardware work consisting in testing the Flash-ADCs that are the core of the main acquisition system of the experiment. Subsequently, it presents analyses performed on Monte Carlo simulations towards the optimization of the detector design. This work was composed of analyses to choose some detector components with the appropriate natural radioactivity contamination, analyses for the best achievable energy resolution and the most stable and robust way of triggering. The work on the optimization of the detector together with the acquired knowledge on the Flash-ADCs led us to envisage the possibility of a new spatial reconstruction based on the time of flight. All these contributions to the experiment are described in details throughout this manuscript. (author)

  2. Measurement of the neutrino mixing angle θ13 with the Double Chooz experiment

    Ostrovskiy, Igor

    2009-10-01

    The neutrino mixing angle θ13 is last one which value is still unknown. Measuring the θ13 is important for completing our understanding of three flavor neutrino oscillations. Moreover, leptonic CP violation could only be measured in case the value of θ13 is not zero. The current best limit (^2(2θ13)Ardennes. Described in this talk, is another experiment, Double Chooz, that is being prepared at the same site. The Double Chooz experiment offers several fundamental improvements and is aiming to surpass the current limit by an order of magnitude (^2(2θ13) < 0.03). Details of the detector design, overview of systematic errors and expected sensitivity, as well as current status of the experiment are presented.

  3. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    Hofmann, Martin Alexander

    2012-01-01

    Evidence for physics beyond the well-established standard model of particle physics is found in the sector of neutrino physics, in particular in neutrino oscillations, and in experimental hints requiring the presence of Dark Matter. Neutrino oscillations demand the neutrinos to be massive and at least four additional parameters, three mixing angles and one phase, are introduced. A non-vanishing value for the third mixing angle, θ 13 , has only recently been found, amongst others by the reactor antineutrino disappearance experiment Double Chooz. This experiment detects anti ν e 's by means of the Inverse Beta Decay (IBD), which has a clear signature that can very effectively be discriminated from most of the background. However, some background still survives the selection cuts applied to the data, partly induced by radioactivity. In order to determine the amount of radioimpurities in the detector, germanium spectroscopy measurements and neutron activation analyses have been carried out for various parts of the Double Chooz far detector. A dedicated Monte-Carlo simulation was performed to obtain the singles event rate induced by the identified radioimpurities in the fiducial volume of Double Chooz. In the present thesis, parts from the outer detector systems, as well as components of the inner detector liquids were measured. In sum, a singles rate of less than 0.35 Hz above the antineutrino detection threshold of 0.7 MeV has been found. This is by far below the design goal of Double Chooz of ∝ 20 Hz. The analysis of bismuth-polonium (BiPo) coincidences in the first Double Chooz data allows to directly determine the number of decays from the U- and the Th-decay chain in the active detector parts. Assuming radioactive equilibrium, concentrations of (1.71±0.08).10 -14 (g)/(g) for uranium and (8.16±0.49).10 -14 (g)/(g) for thorium have been found, which are also well below the design goal of Double Chooz (2.10 -13 (g)/(g)). Both gamma spectroscopy measurements and

  4. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    Hofmann, Martin Alexander

    2012-11-27

    Evidence for physics beyond the well-established standard model of particle physics is found in the sector of neutrino physics, in particular in neutrino oscillations, and in experimental hints requiring the presence of Dark Matter. Neutrino oscillations demand the neutrinos to be massive and at least four additional parameters, three mixing angles and one phase, are introduced. A non-vanishing value for the third mixing angle, {theta}{sub 13}, has only recently been found, amongst others by the reactor antineutrino disappearance experiment Double Chooz. This experiment detects anti {nu}{sub e}'s by means of the Inverse Beta Decay (IBD), which has a clear signature that can very effectively be discriminated from most of the background. However, some background still survives the selection cuts applied to the data, partly induced by radioactivity. In order to determine the amount of radioimpurities in the detector, germanium spectroscopy measurements and neutron activation analyses have been carried out for various parts of the Double Chooz far detector. A dedicated Monte-Carlo simulation was performed to obtain the singles event rate induced by the identified radioimpurities in the fiducial volume of Double Chooz. In the present thesis, parts from the outer detector systems, as well as components of the inner detector liquids were measured. In sum, a singles rate of less than 0.35 Hz above the antineutrino detection threshold of 0.7 MeV has been found. This is by far below the design goal of Double Chooz of {proportional_to} 20 Hz. The analysis of bismuth-polonium (BiPo) coincidences in the first Double Chooz data allows to directly determine the number of decays from the U- and the Th-decay chain in the active detector parts. Assuming radioactive equilibrium, concentrations of (1.71{+-}0.08).10{sup -14}(g)/(g) for uranium and (8.16{+-}0.49).10{sup -14}(g)/(g) for thorium have been found, which are also well below the design goal of Double Chooz (2.10{sup -13

  5. Neutrinos oscillations researches near a nuclear reactor

    Laiman, M.

    1999-01-01

    This thesis deals with the research of neutrinos oscillations near the Chooz B nuclear power plant in the Ardennes. The first part presents the framework of the researches and the chosen detector. The second part details the antineutrinos flux calculus from the reactors and the calculus of the expected events. The analysis procedure is detailed in the last part from the calibration to the events selection. (A.L.B.)

  6. Nuclear energy. The innovations of the N4 reactor

    Anon.

    1998-01-01

    The coupling to the electric network of the two first units of N4 type reactors, on the site of Chooz in the Ardennes, marks the third great step of the French nuclear programme of PWR type reactors, after the realization of 34 units of 900 MWe and 20 units of 1300 M We. The nuclear boiler N4, realizes a new evolution in power, in performances and in reliability. (N.C.)

  7. Characterization, modelization and optimization of the Double Chooz acrylic vessels: physics impact

    Queval, R.

    2010-01-01

    Double Chooz is one of the new generation experiments designed to measure the last unknown leptonic mixing angle, θ 13 . Il studies the oscillations of electronic antineutrinos produced by the Chooz nuclear power plant. Our knowledge on θ 13 can be improved by reducing both statistical errors (increasing both the detector size and run time) and systematic errors (using identical near and far detectors). Also, special care is dedicated to analyze backgrounds generated by natural radioactivity and cosmic ray interactions. The work presented here mostly focuses on Target and Gamma Catcher acrylic vessels, in the core of the detector. A new material designed for the experiment was developed since no pre-existing material met the required conditions. This material was characterized optically, to maximize light transmission and reduce the induced dead zone. With this in mind, a physics study of the Target vessel design was performed to identify any spectral distortion or count rate modification it could induce. As far as backgrounds are concerned, the material is radio-pure enough so that the singles rate coming from acrylic is negligible compared to the one from the photomultiplier tubes. An unknown single source is coming from the external contamination in the detector, such as dust. This is why we defined cleanliness goals for the detector fabrication and integration. These goals were met, thanks to well-defined protocols and careful team work. After three years of data taking, Double Chooz could disentangle an oscillation signal at 3α for sin 2 2θ 13 ≥ 0.05 - 0.06. If no oscillations were observed, the experiment could give an upper limit on sin 2 2θ 13 of 0.02 - 0.03 at 90 % C.L. (author) [fr

  8. The treatment of low level effluents by flocculation and settling at the Chooz nuclear power plant

    Petteau, J.L.; Roofthooft, R.

    1989-01-01

    At the Chooz plant, radioactive effluents were formerly treated by evaporation, but because throughput was low, another method was studied. After laboratory tests, a 500 L/h flocculation and settling pilot plant was constructed, followed later by a 5 m 3 /h installation. The main isotopes eliminated are caesium-134 and caesium-137. Flocculation with copper ferrocyanide reduces the total activity to less than 500 Bq/L. The installation described in the paper was commissioned in 1984 and has been in industrial operation since 1985, processing all types of effluent. The evaporator can be set aside for boric acid recovery. (author). 3 figs, 1 tab

  9. Study of the Light Emission Process from the Double Chooz Photomultipliers

    Calvo, E.; Cerrada, M.; Crespo, J. I.; Gil-Botella, I.; Jimenez, S.; Lopez, M.; Novella, P.; Palomares, C.; Santorelli, R.; Verdugo, A.

    2012-09-13

    In this document we present a study of the light emitted by the base of a Hamamatsu R7081MOD-ASSY photomultiplier (PMT) of the same type used in the Double Chooz experiment. Several characteristic features of the light signal have been found in terms of amplitude, length and pulse shape. Additional investigations on the properties of the epoxy used to cover the photomultiplier base have been carried out. A possible explanation of the light emission process is discussed at the end of the study. (Author) 1 ref.

  10. Inspection of Chooz power plant after ten years operation

    Saglio, Robert.

    1978-01-01

    This report is intended to discuss the results from the complete technical audit of the vessel effected in 1976 at the Ardennes reactor (CNA 305 MWe). This audit had a special character as far as this power plant has never been inspected before: the start-up had taken place in 1967 and was then prior to the development of French regulations (and even to the first version of the ASME code, Section XI). In that time, no inspection was expected; it has yet been possible to have a complete audit in ten days. The automatic start-up of focused ultrasonic testing so appeared to have reached the required reliability and a good sensitivity [fr

  11. B2-B2.5 code benchmarking

    Dekeyser, W.; Baelmans, M; Voskoboynikov, S.; Rozhansky, V.; Reiter, D.; Wiesen, S.; Kotov, V.; Boerner, P.

    2011-01-15

    ITER-IO currently (and since about 15 years) employs the SOLPS4.xxx code for its divertor design, currently version SOLPS4.3. SOLPS.xxx is a special variant of the B2-EIRENE code, which was originally developed by an European consortium (FZ Juelich, AEA Culham, ERM Belgium/KU Leuven) in the late eighties and early nineties of the last century under NET contracts. Until today even the very similar edge plasma codes within the SOLPS family, if run on a seemingly identical choice of physical parameters, still sometimes disagree significantly with each other. It is obvious that in computational engineering applications, as they are carried out for the various ITER divertor aspects with SOLPS4.3 for more than a decade now, any transition from one to another code must be fully backward compatible, or, at least, the origin of differences in the results must be identified and fully understood quantitatively. In this report we document efforts undertaken in 2010 to ultimately eliminate the third issue. For the kinetic EIRENE part within SOLPS this backward compatibility (back until 1996) was basically achieved (V. Kotov, 2004-2006) and SOLPS4.3 is now essentially up to date with the current EIRENE master maintained at FZ Juelich. In order to achieve a similar level of reproducibility for the plasma fluid (B2, B2.5) part, we follow a similar strategy, which is quite distinct from the previous SOLPS benchmark attempts: the codes are ''disintegrated'' and pieces of it are run on smallest (i.e. simplest) problems. Only after full quantitative understanding is achieved, the code model is enlarged, integrated, piece by piece again, until, hopefully, a fully backward compatible B2 / B2.5 ITER edge plasma simulation will be achieved. The status of this code dis-integration effort and its findings until now (Nov. 2010) are documented in the present technical note. This work was initiated in a small workshop by the three partner teams of KU Leuven, St. Petersburg

  12. Contextualized B2B Registries

    Radetzki, U; Boniface, M.J.; Surridge, M.

    2007-01-01

    Abstract. Service discovery is a fundamental concept underpinning the move towards dynamic service-oriented business partnerships. The business process for integrating service discovery and underlying registry technologies into busi-ness relationships, procurement and project management functions has not been examined and hence existing Web Service registries lack capabilities required by business today. In this paper we present a novel contextualized B2B registry that supports dynamic regist...

  13. Reactor

    Toyama, Masahiro; Kasai, Shigeo.

    1978-01-01

    Purpose: To provide a lmfbr type reactor wherein effusion of coolants through a loop contact portion is reduced even when fuel assemblies float up, and misloading of reactor core constituting elements is prevented thereby improving the reactor safety. Constitution: The reactor core constituents are secured in the reactor by utilizing the differential pressure between the high-pressure cooling chamber and low-pressure cooling chamber. A resistance port is formed at the upper part of a connecting pipe, and which is connect the low-pressure cooling chamber and the lower surface of the reactor core constituent. This resistance part is formed such that the internal sectional area of the connecting pipe is made larger stepwise toward the upper part, and the cylinder is formed larger so that it profiles the inner surface of the connecting pipe. (Aizawa, K.)

  14. Reactor

    Ikeda, Masaomi; Kashimura, Kazuo; Inoue, Kazuyuki; Nishioka, Kazuya.

    1979-01-01

    Purpose: To facilitate the construction of a reactor containment building, whereby the inspections of the outer wall of a reactor container after the completion of the construction of the reactor building can be easily carried out. Constitution: In a reactor accommodated in a container encircled by a building wall, a space is provided between the container and the building wall encircling the container, and a metal wall is provided in the space so that it is fitted in the building wall in an attachable or detatchable manner. (Aizawa, K.)

  15. Marketing Optimization for B2B Market

    Kaynova Tatyana V.

    2012-01-01

    The article presents market definition B2B, the necessity to optimize marketing B2B market, provides a system for B2B-marketing and developed stages of its formation. On this basis it was identified key factors of customer loyalty and are the stages of development of loyalty programs for customers market B2B.

  16. The Vaporization of B2O3(l) to B2O3(g) and B2O2(g)

    Jacobson, Nathan S.; Myers, Dwight L.

    2011-01-01

    The vaporization of B2O3 in a reducing environment leads to formation of both B2O3(g) and B2O2(g). While formation of B2O3(g) is well understood, many questions about the formation of B2O2(g) remain. Previous studies using B(s) + B2O3(l) have led to inconsistent thermodynamic data. In this study, it was found that after heating, B(s) and B2O3(l) appear to separate and variations in contact area likely led to the inconsistent vapor pressures of B2O2(g). To circumvent this problem, an activity of boron is fixed with a two-phase mixture of FeB and Fe2B. Both second and third law enthalpies of formation were measured for B2O2(g) and B2O3(g). From these the enthalpies of formation at 298.15 K are calculated to be -479.9 +/- 41.5 kJ/mol for B2O2(g) and -833.4 +/- 13.1 kJ/mol for B2O3(g). Ab initio calculations to determine the enthalpies of formation of B2O2(g) and B2O3(g) were conducted using the W1BD composite method and show good agreement with the experimental values.

  17. Cosmic-muon characterization and annual modulation measurement with Double Chooz detectors

    Abrahão, T.; Anjos, J.C. dos [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, RJ, 22290-180 (Brazil); Almazan, H.; Buck, C. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Appel, S. [Physik Department, Technische Universität München, 85748 Garching (Germany); Baussan, E.; Brugière, T. [IPHC, Université de Strasbourg, CNRS/IN2P3, 67037 Strasbourg (France); Bekman, I. [III. Physikalisches Institut, RWTH Aachen University, 52056 Aachen (Germany); Bezerra, T.J.C. [SUBATECH, CNRS/IN2P3, Université de Nantes, Ecole des Mines de Nantes, 44307 Nantes (France); Bezrukov, L. [Institute of Nuclear Research of the Russian Academy of Sciences, Moscow 117312 (Russian Federation); Blucher, E. [The Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Busenitz, J. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487 (United States); Cabrera, A. [AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, 75205 Paris Cedex 13 (France); Camilleri, L.; Carr, R. [Columbia University, New York, New York 10027 (United States); Cerrada, M. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, CIEMAT, 28040, Madrid (Spain); Chauveau, E. [Research Center for Neutrino Science, Tohoku University, Sendai 980-8578 (Japan); Chimenti, P., E-mail: hgomez@apc.univ-paris7.fr [Universidade Federal do ABC, UFABC, Santo André, SP, 09210-580 (Brazil); and others

    2017-02-01

    A study on cosmic muons has been performed for the two identical near and far neutrino detectors of the Double Chooz experiment, placed at ∼120 and ∼300 m.w.e. underground respectively, including the corresponding simulations using the MUSIC simulation package. This characterization has allowed us to measure the muon flux reaching both detectors to be (3.64 ± 0.04) × 10{sup −4} cm{sup −2}s{sup −1} for the near detector and (7.00 ± 0.05) × 10{sup −5} cm{sup −2}s{sup −1} for the far one. The seasonal modulation of the signal has also been studied observing a positive correlation with the atmospheric temperature, leading to an effective temperature coefficient of α {sub T} = 0.212 ± 0.024 and 0.355 ± 0.019 for the near and far detectors respectively. These measurements, in good agreement with expectations based on theoretical models, represent one of the first measurements of this coefficient in shallow depth installations.

  18. Cosmic-muon characterization and annual modulation measurement with Double Chooz detectors

    Abrahão, T.; Almazan, H.; dos Anjos, J. C.; Appel, S.; Baussan, E.; Bekman, I.; Bezerra, T. J. C.; Bezrukov, L.; Blucher, E.; Brugière, T.; Buck, C.; Busenitz, J.; Cabrera, A.; Camilleri, L.; Carr, R.; Cerrada, M.; Chauveau, E.; Chimenti, P.; Corpace, O.; Crespo-Anadón, J. I.; Dawson, J. V.; Dhooghe, J.; Djurcic, Z.; Dracos, M.; Etenko, A.; Fallot, M.; Franco, D.; Franke, M.; Furuta, H.; Gil-Botella, I.; Giot, L.; Givaudan, A.; Gögger-Neff, M.; Gómez, H.; Gonzalez, L. F. G.; Goodman, M.; Hara, T.; Haser, J.; Hellwig, D.; Hourlier, A.; Ishitsuka, M.; Jochum, J.; Jollet, C.; Kale, K.; Kampmann, P.; Kaneda, M.; Kaplan, D. M.; Kawasaki, T.; Kemp, E.; de Kerret, H.; Kryn, D.; Kuze, M.; Lachenmaier, T.; Lane, C.; Laserre, T.; Lastoria, C.; Lhuillier, D.; Lima, H.; Lindner, M.; López-Castaño, J. M.; LoSecco, J. M.; Lubsandorzhiev, B.; Maeda, J.; Mariani, C.; Maricic, J.; Matsubara, T.; Mention, G.; Meregaglia, A.; Miletic, T.; Minotti, A.; Nagasaka, Y.; Navas-Nicolás, D.; Novella, P.; Oberauer, L.; Obolensky, M.; Onillon, A.; Oralbaev, A.; Palomares, C.; Pepe, I.; Pronost, G.; Reinhold, B.; Rybolt, B.; Sakamoto, Y.; Santorelli, R.; Schönert, S.; Schoppmann, S.; Sharankova, R.; Sibille, V.; Sinev, V.; Skorokhvatov, M.; Soiron, M.; Soldin, P.; Stahl, A.; Stancu, I.; Stokes, L. F. F.; Strait, M.; Suekane, F.; Sukhotin, S.; Sumiyoshi, T.; Sun, Y.; Svoboda, B.; Tonazzo, A.; Veyssiere, C.; Vivier, M.; Wagner, S.; Wiebusch, C.; Wurm, M.; Yang, G.; Yermia, F.; Zimmer, V.

    2017-02-01

    A study on cosmic muons has been performed for the two identical near and far neutrino detectors of the Double Chooz experiment, placed at ~120 and ~300 m.w.e. underground respectively, including the corresponding simulations using the MUSIC simulation package. This characterization has allowed us to measure the muon flux reaching both detectors to be (3.64 ± 0.04) × 10-4 cm-2s-1 for the near detector and (7.00 ± 0.05) × 10-5 cm-2s-1 for the far one. The seasonal modulation of the signal has also been studied observing a positive correlation with the atmospheric temperature, leading to an effective temperature coefficient of αT = 0.212 ± 0.024 and 0.355 ± 0.019 for the near and far detectors respectively. These measurements, in good agreement with expectations based on theoretical models, represent one of the first measurements of this coefficient in shallow depth installations.

  19. Cosmic-muon characterization and annual modulation measurement with Double Chooz detectors

    Abrahão, T.; Anjos, J.C. dos; Almazan, H.; Buck, C.; Appel, S.; Baussan, E.; Brugière, T.; Bekman, I.; Bezerra, T.J.C.; Bezrukov, L.; Blucher, E.; Busenitz, J.; Cabrera, A.; Camilleri, L.; Carr, R.; Cerrada, M.; Chauveau, E.; Chimenti, P.

    2017-01-01

    A study on cosmic muons has been performed for the two identical near and far neutrino detectors of the Double Chooz experiment, placed at ∼120 and ∼300 m.w.e. underground respectively, including the corresponding simulations using the MUSIC simulation package. This characterization has allowed us to measure the muon flux reaching both detectors to be (3.64 ± 0.04) × 10 −4 cm −2 s −1 for the near detector and (7.00 ± 0.05) × 10 −5 cm −2 s −1 for the far one. The seasonal modulation of the signal has also been studied observing a positive correlation with the atmospheric temperature, leading to an effective temperature coefficient of α T = 0.212 ± 0.024 and 0.355 ± 0.019 for the near and far detectors respectively. These measurements, in good agreement with expectations based on theoretical models, represent one of the first measurements of this coefficient in shallow depth installations.

  20. The reactor antineutrino anomalies

    Haser, Julia; Buck, Christian; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2016-07-01

    Major discoveries were made in the past few years in the field of neutrino flavour oscillation. Nuclear reactors produce a clean and intense flux of electron antineutrinos and are thus an essential neutrino source for the determination of oscillation parameters. Most currently the reactor antineutrino experiments Double Chooz, Daya Bay and RENO have accomplished to measure θ{sub 13}, the smallest of the three-flavour mixing angles. In the course of these experiments two anomalies emerged: (1) the reanalysis of the reactor predictions revealed a deficit in experimentally observed antineutrino flux, known as the ''reactor antineutrino anomaly''. (2) The high precision of the latest generation of neutrino experiments resolved a spectral shape distortion relative to the expected energy spectra. Both puzzles are yet to be solved and triggered new experimental as well as theoretical studies, with the search for light sterile neutrinos as most popular explanation for the flux anomaly. This talk outlines the two reactor antineutrino anomalies. Discussing possible explanations for their occurrence, recent and upcoming efforts to solve the reactor puzzles are highlighted.

  1. 32 CFR 806b.2 - Basic guidelines.

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Basic guidelines. 806b.2 Section 806b.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.2 Basic guidelines. This part implements the Privacy Act of 1974...

  2. Non-standard interaction effects at reactor neutrino experiments

    Ohlsson, Tommy; Zhang, He

    2009-01-01

    We study non-standard interactions (NSIs) at reactor neutrino experiments, and in particular, the mimicking effects on θ 13 . We present generic formulas for oscillation probabilities including NSIs from sources and detectors. Instructive mappings between the fundamental leptonic mixing parameters and the effective leptonic mixing parameters are established. In addition, NSI corrections to the mixing angles θ 13 and θ 12 are discussed in detailed. Finally, we show that, even for a vanishing θ 13 , an oscillation phenomenon may still be observed in future short baseline reactor neutrino experiments, such as Double Chooz and Daya Bay, due to the existences of NSIs

  3. Reactors

    Shah, Vivek; Vaz Salles, Marcos António

    2018-01-01

    The requirements for OLTP database systems are becoming ever more demanding. Domains such as finance and computer games increasingly mandate that developers be able to encode complex application logic and control transaction latencies in in-memory databases. At the same time, infrastructure...... engineers in these domains need to experiment with and deploy OLTP database architectures that ensure application scalability and maximize resource utilization in modern machines. In this paper, we propose a relational actor programming model for in-memory databases as a novel, holistic approach towards......-level function calls. In contrast to classic transactional models, however, reactors allow developers to take advantage of intra-transaction parallelism and state encapsulation in their applications to reduce latency and improve locality. Moreover, reactors enable a new degree of flexibility in database...

  4. Experimental modal analysis of the steam inlet pipe to the Chooz B1 high pressure turbine

    Guihot, O.; Anne, J.P.; Chartain, G.; Le Pironnec, D.

    1993-05-01

    This report presents the results of the modal analysis carried out on one of the steam inlet pipe of the high pressure turbine of the Chooz B1 power plant. This experimental analysis is made within the frame of the research and development project ''dynamical, acoustical and aerodynamical behaviour of the turbogenerator N4''. This research program provides amongst others, numerical studies with the software CIRCUS and ASTER, in order to verify the dynamical behaviour of the designed inlet pipe. The numerical models will be updated from results of the experimental modal analysis to improve the numerical representation of this pipe. All the identified modes in the frequency band [5.2000] Hz are presented in the report. The modal characteristics of the main modes are detailed. Further analysis have been made, in order ease the updating of the numerical models. They consisted in an analysis of the evolution of the dynamical behaviour due to a change of the boundary conditions of the inlet valve frame on one hand and resulting from the presence of an additional mass on the pipe, at the level of the middle flange, on the other hand. The analysis made in low frequency range shows that the pipe is thoroughly embedded in the frame of the high pressure turbine. On the other hand, the boundary conditions on the inlet valve frame are more difficult to determine, because the dynamical behaviour of the valve frame and the upper pipe can not be uncoupled from the considered pipe. The main shell modes of ranks 2, 3 and 4 have been very accurately identified. The most relevant modes to update the numerical models are given. (authors). 48 figs., 18 tabs., 4 refs

  5. IAEA Concludes Safety Review at Chooz Nuclear Power Plant in France

    2013-01-01

    Full text: An IAEA-led international team of nuclear safety experts noted good practices and made recommendations to reinforce safety measures during a review of operational safety at France's Chooz Nuclear Power Plant (NPP) that concluded today. The Operational Safety Review Team (OSART) was assembled at the French Government's request. The in-depth review, which began 17 June, focused on aspects essential to the safe operation of the NPP. The team comprised experts from Switzerland, Belgium, Germany, China, India, United Kingdom, Czech Republic, Canada, Hungary and the IAEA. The review covered the areas of management, organization and administration; training and qualification of personnel; operations; maintenance; technical support; operating experience; radiation protection; chemistry; emergency planning and preparedness; and severe accident management. The conclusions of the review are based on the IAEA's Safety Standards. The OSART team identified good plant practices that will be shared with the rest of the nuclear industry for consideration. Examples include: The plant has a professional development programme as part of a joint employment effort shared by the plant and its contractors. This enables trainees to develop professional capability, understand practices and gain experience from other nuclear power plants in terms of work planning and coordination; The plant has built a strong relationship between the on-shift response team of the plant and the local fire brigade to improve firefighting and rescue operations; Self-assessment groups discuss and resolve specific issues within operations, empowering operations personnel to take ownership of improvement programmes; and The plant has improved warnings at entrances to all o range zones , areas of elevated dose rates to which only authorized staff have access. The team identified a number of improvements to operational safety at Chooz NPP. Examples include: The plant should review its process for the

  6. Characterization of large-area photomultipliers under low magnetic fields: Design and performance of the magnetic shielding for the Double Chooz neutrino experiment

    Calvo, E.; Cerrada, M.; Fernandez-Bedoya, C.; Gil-Botella, I.; Palomares, C.; Rodriguez, I.; Toral, F.; Verdugo, A.

    2010-01-01

    A precise quantitative measurement of the effect of low magnetic fields in Hamamatsu R7081 photomultipliers has been performed. These large-area photomultipliers will be used in the Double Chooz neutrino experiment. A magnetic shielding has been developed for these photomultipliers. Its design and performance is also reported in this paper.

  7. Lattice dynamical and thermodynamical properties of ReB2, RuB2, and OsB2 compounds in the ReB2 structure

    Deligoz, E.; Colakoglu, K.; Ciftci, Y. O.

    2012-01-01

    Structural and lattice dynamical properties of ReB 2 , RuB 2 , and OsB 2 in the ReB 2 structure are studied in the framework of density functional theory within the generalized gradient approximation. The present results show that these compounds are dynamically stable for the considered structure. The temperature-dependent behaviors of thermodynamical properties such as internal energy, free energy, entropy, and heat capacity are also presented. The obtained results are in good agreement with the available experimental and theoretical data

  8. Reactor

    Fujibayashi, Toru.

    1976-01-01

    Object: To provide a boiling water reactor which can enhance a quake resisting strength and flatten power distribution. Structure: At least more than four fuel bundles, in which a plurality of fuel rods are arranged in lattice fashion which upper and lower portions are supported by tie-plates, are bundled and then covered by a square channel box. The control rod is movably arranged within a space formed by adjoining channel boxes. A spacer of trapezoidal section is disposed in the central portion on the side of the channel box over substantially full length in height direction, and a neutron instrumented tube is disposed in the central portion inside the channel box. Thus, where a horizontal load is exerted due to earthquake or the like, the spacers come into contact with each other to support the channel box and prevent it from abnormal vibrations. (Furukawa, Y.)

  9. Using NJOY99 and MCNP4B2 to Estimate the Radiation Damage Displacements per Atom per Second in Steel Within the Boiling Water Reactor Core Shroud and Vessel Wall from Reactor-Grade Mixed-Oxide/Uranium Oxide Fuel for the Nuclear Power Plant at Laguna Verde, Veracruz, Mexico

    Vickers, Lisa

    2003-01-01

    The government of Mexico has expressed interest in utilizing the Laguna Verde boiling water reactor (BWR) nuclear power plant for the disposition of reprocessed spent uranium oxide (UOX) fuel in the form of reactor-grade mixed-oxide (MOX) fuel. MOX fuel would replace spent UOX fuel as a fraction in the core from 18 to 30% depending on the fuel loading cycle. MOX fuel is expected to increase the neutron fluence, flux, fuel centerline temperature, reactor core pressure, and yield higher energy neutrons.There is concern that a core with a fraction of MOX fuel (i.e., increased 239 Pu wt%) would increase the radiation damage displacements per atom per second (dpa-s -1 ) in steel within the core shroud and vessel wall as compared to only conventional, enriched UOX fuel in the core. The evaluation of radiation damage within the core shroud and vessel wall is a concern because of the potentially adverse affect to personnel and public safety, environment, and operating life of the reactor.The primary uniqueness of this paper is the computation of radiation damage (dpa-s -1 ) using NJOY99-processed cross sections for steel within the core shroud and vessel wall. Specifically, the unique radiation damage results are several orders of magnitude greater than results of previous works. In addition, the conclusion of this paper was that the addition of the maximum fraction of one-third MOX fuel to the LV1 BWR core did significantly increase the radiation damage in steel within the core shroud and vessel wall such that without mitigation of radiation damage by periodic thermal annealing or reduction in operating parameters such as neutron fluence, core temperature, and pressure, it posed a potentially adverse affect to the personnel and public safety, environment, and operating life of the reactor

  10. B11 NMR in the layered diborides OsB2 and RuB2

    Suh, B. J.; Zong, X.; Singh, Y.; Niazi, A.; Johnston, D. C.

    2007-10-01

    B11 nuclear magnetic resonance (NMR) measurements have been performed on B11 enriched OsB2 and RuB2 polycrystalline powder samples in an external field of 4.7T and in the temperature range, 4.2KOsB2 and RuB2 , respectively. The experimental results indicate that a p character dominates the conduction electron wave function at the B site with a negligibly small s character in both compounds.

  11. Ni-ZrB2 electrocomposites

    Pushpavanam, M.; Natarajan, S.R.

    1992-01-01

    New generation materials require high temperature oxidation resistance besides many other tribological properties. Ni-ZrB 2 composites and their properties are dealt with in this paper. (author). 7 refs., 3 figs., 4 tabs

  12. A Model of B2B Exchanges

    Gabor Fath; Miklos Sarvary

    2001-01-01

    B2B exchanges are revolutionizing the way businesses will buy and sell a variety of intermediary products and services. It is estimated that most of the roughly $7 trillion worth of business transactions are likely to go through these new institutions within the next decade. This paper tries to understand the economics governing the transactions within B2B exchanges and analyze their likely evolution over time. In doing so, we start by providing the rigorous definitions to a number of critica...

  13. Hotelzon's B2B content marketing plan

    Nguyen, Trang

    2015-01-01

    This thesis follows a research-based structure. The objective of this research was to help the case company Hotelzon develop a practical business-to-business (B2B) content marketing plan to engage new customers. The research topic came up when the case company named Hotelzon started expanding its business to many other countries. Therefore, attracting new prospects has become a critical issue to B2B corporates in this online world and constantly changing business environment. The first pa...

  14. Comparison of monoclonal antibodies and rabbit antisera in B2 microglobulin (B2m) radioimmunoassay

    Vincent, C.

    1981-01-01

    Human B2m is a globular protein devoid of carbohydrates and is composed of 100 aminoacids with an intrachain disulfide bridge in position 25-81. Its aminoacid sequence and three dimensional structure shows a partial homology with the constant domains of immunoglobulins. B2m has been detected at the surface of nearly all cell types with the exception of erythrocytes and trophoblastic cells and also in all biological fluids. On the cell surface B2m is found non-covalently associated with HLA molecules, and in serum and urine only a small part of the B2m is associated with HLA heavy chain, the remaining is found as free B2m. The aim of this paper is firstly to try to demonstrate the presence of two types of epitopes one of them specific of free B2m and secondly to compare monoclonal antibodies with rabbit antisera for B2m radioimmunoassay. (Auth.)

  15. Combined potential of future long-baseline and reactor experiments

    Huber, P.; Lindner, M.; Rolinec, M.; Schwetz, T.; Winter, W.

    2005-01-01

    We investigate the determination of neutrino oscillation parameters by experiments within the next ten years. The potential of conventional beam experiments (MINOS, ICARUS, OPERA), superbeam experiments (T2K, NOνA), and reactor experiments (D-CHOOZ) to improve the precision on the 'atmospheric' parameters Δm 31 2 , θ 23 , as well as the sensitivity to θ 13 are discussed. Further, we comment on the possibility to determine the leptonic CP-phase and the neutrino mass hierarchy if θ 13 turns out to be large

  16. Preparation of high quality superconducting thin MgB2 films for electronics

    Surdu, Andrei; Zdravkov, Vladimir; Sidorenko, Anatolie; Rossolenko, Anna; Ryazanov, Valerii; Bdikin, Igor; Kroemer, Oliver; Nold, Eberhard; Koch, Thomas; Schimmel, Thomas

    2007-01-01

    In this work we report the growth of high-Tc MgB 2 smooth films which are prepared in a two-step process: 1) deposition of the precursor films and 2) their annealing in Mg vapor with a specially designed, reusable reactor. Our method opens perspectives for the use of MgB 2 films in microelectronics, especially for high-frequency applications. (authors)

  17. A unified analysis of the reactor neutrino program towards the measurement of the θ13 mixing angle

    Mention, G.; Motta, D.; Lasserre, Th.

    2007-04-01

    We present in this article a detailed quantitative discussion of the measurement of the leptonic mixing angle θ 13 through currently scheduled reactor neutrino oscillation experiments. We thus focus on Double Chooz (Phase I and II), Daya Bay (Phase I and II) and RENO experiments. We perform a unified analysis, including systematics, backgrounds and accurate experimental setup in each case. Each identified systematic error and background impact has been assessed on experimental setups following published data when available and extrapolating from Double Chooz acquired knowledge otherwise. After reviewing the experiments, we present a new analysis of their sensitivities to sin 2 (2θ 13 ) and study the impact of the different systematics based on the pulls approach. Through this generic statistical analysis we discuss the advantages and drawbacks of each experimental setup. (authors)

  18. A unified analysis of the reactor neutrino program towards the measurement of the {theta}{sub 13} mixing angle

    Mention, G [DAPNIA/SPP, CEA Saclay, 91191 Gif sur Yvette (France)

    2008-05-15

    We presented a detailed quantitative discussion of the measurement of the leptonic mixing angle {theta}{sub 13} through currently scheduled reactor neutrino oscillation experiments. We focussed on Double Chooz (Phase I and II), Daya Bay (Phase I and II) and RENO experiments. We performed a unified analysis, including systematics, backgrounds and accurate experimental setup in each case. Each identified systematical uncertainty and background impact has been assessed on experimental setups following published data when available and extrapolating from Double Chooz acquired knowledge otherwise. We sum up, here, a new common analysis of their sensitivities to sin{sup 2}(2{theta}{sub 13}) and study the impact of the different systematics based on the pulls approach. Through this generic statistical analysis we discuss the advantages and drawbacks of each experimental setup.

  19. A unified analysis of the reactor neutrino program towards the measurement of the {theta}{sub 13} mixing angle

    Mention, G.; Motta, D. [DAPNIA/SPP, CEA Saclay, 91191 Gif sur Yvette (France); Lasserre, Th. [DAPNIA/SPP, CEA Saclay, 91191 Gif sur Yvette (France); Laboratoire Astroparticule et Cosmologie (APC), Paris (France)

    2007-04-15

    We present in this article a detailed quantitative discussion of the measurement of the leptonic mixing angle {theta}{sub 13} through currently scheduled reactor neutrino oscillation experiments. We thus focus on Double Chooz (Phase I and II), Daya Bay (Phase I and II) and RENO experiments. We perform a unified analysis, including systematics, backgrounds and accurate experimental setup in each case. Each identified systematic error and background impact has been assessed on experimental setups following published data when available and extrapolating from Double Chooz acquired knowledge otherwise. After reviewing the experiments, we present a new analysis of their sensitivities to sin{sup 2}(2{theta}{sub 13}) and study the impact of the different systematics based on the pulls approach. Through this generic statistical analysis we discuss the advantages and drawbacks of each experimental setup. (authors)

  20. Electronic structure of MgB2

    Abstract. Results of ab initio electronic structure calculations on the compound MgB2 using the. FPLAPW method employing GGA for the exchange-correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, c/a ratio and the bulk modulus, all of which are in excellent ...

  1. Electronic structure of MgB 2

    Results of ab initio electronic structure calculations on the compound MgB2 using the FPLAPW method employing GGA for the exchange-correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with ...

  2. Reactor anti-neutrinos: measurement of the θ13 leptonic mixing angle and search for potential sterile neutrinos

    Collin, A.

    2014-01-01

    The Double Chooz experiment aims to measure the θ 13 mixing angle through the disappearance -induced by the oscillation phenomenon - of anti-neutrinos produced by the Chooz nuclear reactors. In order to reduce systematic uncertainties, the experiment relies on the relative comparison of detected signals in two identical liquid scintillator detectors. The near one, giving the normalization of the emitted flux, is currently being built and will be delivered in spring 2014. The far detector, sensitive to θ 13 , is located at about one kilometer and is taking data since 2011. In this first phase of the experiment, the far detector data are compared to a prediction of the emitted neutrino flux to estimate θ 13 . In this thesis, the Double Chooz experiment and its analysis are presented, especially the background studies and the rejection of parasitic signals due to light emitted by photo-multipliers. Neutron fluxes between the different detector volumes impact the definition of the fiducial volume of neutrino interactions and the efficiency of detection. Detailed studies of these effects are presented. As part of the Double Chooz experiment, studies were performed to improve the prediction of neutrino flux emitted by reactors. This work revealed a deficit of observed neutrino rates in the short baseline experiments of last decades. This deficit could be explained by an oscillation to a sterile state. The Stereo project aims to observe a typical signature of oscillations: the distortion of neutrino spectra both in energy and baseline. This thesis presents the detector concept and simulations as well as sensitivity studies. Background sources and the foreseen shielding are also discussed. (author) [fr

  3. Thermodynamic properties of vitamin B2

    Knyazev, A.V.; Letyanina, I.A.; Plesovskikh, A.S.; Smirnova, N.N.; Knyazeva, S.S.

    2014-01-01

    Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B 2 has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B 2 have been determined for the range from T → 0 to 322 K. • The energy of combustion of the riboflavin has been measured at 298.15 K. • The enthalpy of combustion Δ c H° and the thermodynamic parameters Δ f H°, Δ f S°, Δ f G° have been calculated. - Abstract: In the present work temperature dependence of heat capacity of vitamin B 2 (riboflavin) has been measured for the first time in the range from 6 to 322 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B 2 , namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 322 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the riboflavin has been measured at 298.15 K. The enthalpy of combustion Δ c H° and the thermodynamic parameters Δ f H°, Δ f S°, Δ f G° and of reaction of formation of the riboflavin from simple substances at T = 298.15 K and p = 0.1 MPa have been calculated

  4. Effect of TiB2 Pretreatment on Pt/TiB2 Catalyst Performance

    Huang, Zhen; Lin, Rui; Fan, Renjie; Fan, Qinbai; Ma, Jianxin

    2014-01-01

    Highlights: • We pretreated Titanium diboride by different acids and alkali. • We synthesis the Pt/as-pretreated TiB 2 catalysts by a colloid route. • We investigated the effects of TiB 2 Pretreatment on Pt/TiB 2 Catalyst Performance. • The BET surface area and defects on the surface have a close relationship with the deposition of Pt nanoparticles. - Abstract: Carbon support corrosion of traditional Pt/C catalyst is one of the major contributors causing poor durability of proton exchange membrane fuel cells (PEMFC). Titanium diboride (TiB 2 ) has high electrical conductivity and considerable chemical stability, which making it as a good candidate for catalyst support in PEMFC. In this work, TiB 2 was pretreated by different acid and alkali. The as-obtained samples were characterized by Ex-situ microscopy (ESM) and X-ray diffraction (XRD). The pore size distribution (PSD) was analyzed by using DFT method. The PSD shows distinct volume in mesopore regions (less than 50 nm). The TiB2 pretreated by H 2 O 2 shows the biggest BET surface area of 57 m 2 g −1 and its PSD focus on mesoporous (1.5-8 nm) region, which resulted to high dispersion and better loading of Pt particles. The Hydrogen oxidization reaction (HOR) and oxygen reduction reaction (ORR) activity was characterized by Rotating Disk Electrode (RDE). The Pt/TiB 2 prepared by H 2 O 2 -pretreated TiB 2 using the colloidal method showed better half-cell electrochemical performance. Facile synthetic for the development of Pt/TiB 2 catalysts was developed

  5. Lessons learned from ten years of terrestrial radio - ecological monitoring campaigns conducted around chooz NPP between 1995 and 2005

    Burton, O.; Bourdon, M; Aubinet, M.; Calande, E. C.; Tomasevszky, D.; Sombre, L.

    2006-01-01

    Radio-ecological monitoring campaigns around the Chooz PWR nuclear power plant (Ardennes - France), located at a few kilometres of the Belgian border, have been conducted on the Belgian territory, between 1995 and 2005, with the aim of observing the concentrations of radionuclides of major environmental significance in soils and agricultural products and their time evolution. The following conclusions are drawn from these campaigns : - the time evolution of the observed radioactivity levels remains rather constant ; - except 1 4C which is of natural origin but is also released in airborne discharges of nuclear power plants, the artificial isotopes still significantly detected in the agricultural ecosystem are the 1 37Cs (generated by the Chernobyl accident and the military test explosions) and the 9 0Sr (generated by the military test explosions) ; - grass remains the best indicator of contamination of the agricultural ecosystem by 1 37Cs and 9 0Sr ; - the major contributors to the total soil and plant activities are from far radionuclides of natural origin, the major contributor being 4 0K

  6. Lattice Thermal Conductivity from Atomistic Simulations: ZrB2 and HfB2

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  7. B2B oriented on-line applications generator

    Vintilă Bogdan-Cătălin

    2008-01-01

    B2B applications are presented. Quality characteristics of B2B applications are defined. B2B application structure is defined. The application for contracts is developed. The advantages are identified.

  8. French experience in operating pressurized water reactor power stations. Ten years' operation of the Ardennes power station

    Teste du Bailler, A.; Vedrinne, J.F.

    1978-01-01

    In the paper the experience gained over ten years' operation of the Ardennes (Chooz) nuclear power station is summarized from the point of view of monitoring and control equipment. The reactor was the first pressurized water reactor to be installed in France; it is operated jointly by France and Belgium. The equipment, which in many cases consists of prototypes, was developed for industrial use and with the experience that has now been gained it is possible to evaluate its qualities and defects, the constraints which it imposes and the action that has to be taken in the future. (author)

  9. To be or not B2B?

    Symons, L J

    2001-01-01

    La question du commerce électronique interentreprises par le web (Business to Business, B2B) est posée actuellement par les grands groupes industriels impliqués dans le commerce mondial. Les prévisions sont imposantes, le B2B atteindra le C.A. de 3000 milliards de dollars en 2003. Les conditions d'accès, la façon de procéder des deux organisateurs (ARIBA et COMMERCE ONE) des plus grandes places de marchés actuelles, sont décrites. La base de l'énorme pyramide est le catalogue électronique multilingue UNSPSC (United Nations Standard Products and Services Classification) et l'organisation ECCMA (Electronic Commerce Code Management Association) qui gère le développement des UNSPSC codes en 8 langues. Dans ce contexte, l'auteur (re)-déclare qu'un des efforts principaux à fournir par le CERN est la création de son propre catalogue électronique. Dans la Division ST, une aide partielle à ce vaste programme pourrait être apportée par la normalisation des codes et désignations des pièces de maint...

  10. Doping-Induced Isotopic Mg11B2 Bulk Superconductor for Fusion Application

    Qi Cai

    2017-03-01

    Full Text Available Superconducting wires are widely used for fabricating magnetic coils in fusion reactors. Superconducting magnet system represents a key determinant of the thermal efficiency and the construction/operating costs of such a reactor. In consideration of the stability of 11B against fast neutron irradiation and its lower induced radioactivation properties, MgB2 superconductor with 11B serving as the boron source is an alternative candidate for use in fusion reactors with a severe high neutron flux environment. In the present work, the glycine-doped Mg11B2 bulk superconductor was synthesized from isotopic 11B powder to enhance the high field properties. The critical current density was enhanced (103 A·cm−2 at 20 K and 5 T over the entire field in contrast with the sample prepared from natural boron.

  11. ONLINE ACQUISITIONS IN B2B MODEL

    Constantin SASU

    2016-12-01

    Full Text Available Within the present paper, we propose to review some of the main aspects documented by the academic research so far with regard to the online purchasing behaviour in the B2B online environment (more specifically, in the case of the small and medium-sized companies. Preliminary conclusions reveal that, at least in the case studies, the dominant feature is that the geographic delimitation creates a potential obstacle when it comes to applying a general principle governing the small and medium-sized enterprises. Despite this, we consider that some theoretical elements can be acknowledged, elements from which future research can start to develop theories and hypothesis aimed at better explaining the phenomenon. Furthermore, the fact that the studies are rarely involving the same sector, makes it impossible to generalise the process.

  12. Diffusion in substitutionally disordered B2 intermetallics

    Belova, I.V.; Murch, G.E.

    2002-01-01

    In this paper, a comprehensive diffusion kinetics theory is formulated to describe seamlessly tracer and chemical diffusion in antistructurally disordered B2 intermetallics showing positive and negative deviations from stoichiometry. The theory is based around unit processes consisting of six-jump cycles that can be assisted by intrinsic and extrinsic antistructural atoms of either atomic species. The Ising alloy model is used to illustrate the formalism, but the formalism can be adapted to other models. Expressions are developed for the tracer diffusion coefficients, the phenomenological coefficients, the intrinsic diffusion coefficients, the interdiffusion coefficient and the various correlation factor components. Results for the tracer and collective correlation factors and the vacancy wind factor (in interdiffusion) are in excellent agreement with results from Monte Carlo computer simulations based around single vacancy jumps. (author)

  13. First test of Lorentz violation with a reactor-based antineutrino experiment

    Abe, Y.; Ishitsuka, M.; Konno, T.; Kuze, M.; Aberle, C.; Buck, C.; Hartmann, F.X.; Haser, J.; Kaether, F.; Lindner, M.; Reinhold, B.; Schwetz, T.; Wagner, S.; Watanabe, H.; Anjos, J.C. dos; Gama, R.; Lima, H.P.-Jr.; Pepe, I.M.; Bergevin, M.; Felde, J.; Maesano, C.N.; Bernstein, A.; Bowden, N.S.; Dazeley, S.; Erickson, A.; Keefer, G.; Bezerra, T.J.C.; Furuta, H.; Suekane, F.; Bezrukhov, L.; Lubsandorzhiev, B.K.; Yanovitch, E.; Blucher, E.; Conover, E.; Crum, K.; Strait, M.; Worcester, M.; Busenitz, J.; Goon, J.TM.; Habib, S.; Ostrovskiy, I.; Reichenbacher, J.; Stancu, I.; Sun, Y.; Cabrera, A.; Franco, D.; Kryn, D.; Obolensky, M.; Roncin, R.; Tonazzo, A.; Caden, E.; Damon, E.; Lane, C.E.; Maricic, J.; Miletic, T.; Milincic, R.; Perasso, S.; Smith, E.; Camilleri, L.; Carr, R.; Franke, A.J.; Shaevitz, M.H.; Toups, M.; Cerrada, M.; Crespo-Anadon, J.I.; Gil-Botella, I.; Lopez-Castano, J.M.; Novella, P.; Palomares, C.; Santorelli, R.; Chang, P.J.; Horton-Smith, G.A.; McKee, D.; Shrestha, D.; Chimenti, P.; Classen, T.; Collin, A.P.; Cucoanes, A.; Durand, V.; Fechner, M.; Fischer, V.; Hayakawa, T.; Lasserre, T.; Letourneau, A.; Lhuillier, D.; Mention, G.; Mueller, Th.A.; Perrin, P.; Sida, J.L.; Sinev, V.; Veyssiere, C.

    2012-01-01

    We present a search for Lorentz violation with 8249 candidate electron antineutrino events taken by the Double Chooz experiment in 227.9 live days of running. This analysis, featuring a search for a sidereal time dependence of the events, is the first test of Lorentz invariance using a reactor-based antineutrino source. No sidereal variation is present in the data and the disappearance results are consistent with sidereal time independent oscillations. Under the Standard-Model Extension, we set the first limits on 14 Lorentz violating coefficients associated with transitions between electron and tau flavor, and set two competitive limits associated with transitions between electron and muon flavor. (authors)

  14. Assessment of liquid hydrogen cooled MgB2 conductors for magnetically confined fusion

    Glowacki, B A; Nuttall, W J

    2008-01-01

    Importantly environmental factors are not the only policy-driver for the hydrogen economy. Over the timescale of the development of fusion energy systems, energy security issues are likely to motivate a shift towards both hydrogen production and fusion as an energy source. These technologies combine local control of the system with the collaborative research interests of the major energy users in the global economy. A concept Fusion Island Reactor that might be used to generate H 2 (rather than electricity) is presented. Exploitation of produced hydrogen as a coolant and as a fuel is proposed in conjunction with MgB 2 conductors for the tokomak magnets windings, and electrotechnical devices for Fusion Island's infrastructure. The benefits of using MgB 2 over the Nb-based conductors during construction, operation and decommissioning of the Fusion Island Reactor are presented. The comparison of Nb 3 Sn strands for ITER fusion magnet with newly developed high field composite MgB 2 PIT conductors has shown that at 14 Tesla MgB 2 possesses better properties than any of the Nb 3 Sn conductors produced. In this paper the potential of MgB 2 conductors is examined for tokamaks of both the conventional ITER type and a Spherical Tokamak geometry. In each case MgB 2 is considered as a conductor for a range of field coil applications and the potential for operation at both liquid helium and liquid hydrogen temperatures is considered. Further research plans concerning the application of MgB 2 conductors for Fusion Island are also considered

  15. Chasing {theta}{sub 13} with new reactor neutrino experiments

    Lasserre, Th. [DSM/DAPNIA/SPP, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-12-15

    It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the {theta}{sub 13} mixing angle, free from any parameter degeneracies and correlations induced by matter effect and the unknown leptonic Dirac CP phase. The current best constraint on the third mixing angle comes from the Chooz reactor neutrino experiment sin{sup 2}(2{theta}{sub 13})<0.2 (90 % C.L., {delta}m{sub atm}{sup 2}=2.010{sup -3} eV{sup 2}). Several projects of experiment, with different timescales, have been proposed over the last two years all around the world. Their sensitivities range from sin{sup 2}(2{theta}{sub 13})<0.01 to 0.03, having thus an excellent discovery potential of the {nu}{sub e} fraction of {nu}{sub 3}.

  16. Electronic Commerce in Tourism in China: B2B or B2C?

    Li, Hongxiu; Suomi, Reima

    E-commerce has significantly changed the distribution channels of travel products in the world including China. Online channels are growing important in travel service distribution. In China tourism industry has been developed rapidly with the economic development, more and more international travel service providers are trying to expand their Chinese market through the Internet. This paper sheds lights on the e-commerce development models in China for international travel service providers. It explores the current e-tourism in China from the three different participants in the value chain in tourism industry - consumer, travel agent and travel service provider. The paper also identifies the barriers in B2C arena in international outbound travel market, and discusses the possible approaches for international travel service providers to develop their e-commerce in the huge Chinese market. The results in this study reveal that international travel service providers should focus on B2B model to expand their electronic market in China. B2C development in tourism largely depends on the change of Chinese customers' behavior and the change of international tourism regulations. The findings of the study are expected to assist international travel service providers to understand current e-tourism in China and to support their planning for future e-commerce development in China.

  17. Laser cladding of aluminium using TiB2

    Kumar, S

    2010-03-01

    Full Text Available to that of steel (5) and Tita- nium (6; 7). Previous work con- sists of an effort to make deep laser injection of TiB2 on Al or the creation of in-situ of TiB2 using other reactant particles. In-situ creation of TiB2 suffers from other side effects...

  18. Theoretical study of the ionization of B2H5

    Curtiss, L.A.; Pople, J.A.

    1989-01-01

    Ab initio molecular orbital calculations at the G1 level of theory have been carried out on neutral B 2 H 5 radical, doubly bridged B 2 H + 5 cation, and the first triplet excited state of B 2 H + 5 . Singly bridged B 2 H 5 is 4.0 kcal/mol (without zero-point energies) more stable than doubly bridged B 2 H 5 . Based on this work and previous theoretical work on triply bridged B 2 H + 5 , ionization potentials (vertical and adiabatic) are determined for B 2 H 5 . The adiabatic ionization potentials of the two B 2 H 5 structures are 6.94 eV (singly bridged) and 7.53 eV (doubly bridged). A very large difference is found between the vertical and adiabatic ionization potentials (3.37 eV) of the singly bridged B 2 H 5 structure. The first triplet state of B 2 H + 5 is found to be 4.55 eV higher in energy than the lowest energy B 2 H + 5 cation (triply bridged). The results of this theoretical study support the interpretation of Ruscic, Schwarz, and Berkowitz of their recent photoionization measurements on B 2 H 5

  19. Component Based System Framework for Dynamic B2B Interaction

    Hu jinmin, Jinmin; Grefen, P.W.P.J.

    Business-to-Business (B2B) collaboration is becoming a pivotal way to bring today's enterprises to success in the dynamically changing e-business environment. Though many business-to-business protocols are developed to support B2B interaction, none are generally accepted. A B2B system should support

  20. TRUST IN B2B E-MARKETPLACES

    SEBASTIAN KOT

    2011-01-01

    Full Text Available The paper presents background of B2B exchanges and review of their forms and functionalities. The benefits and fails reasons are noticed. European enterprises interest in B2B trade is next aspect of consideration. Finally, the trust barriers of B2B exchanges are presented.

  1. B-2 Extremely High Frequency SATCOM and Computer Increment 1 (B-2 EHF Inc 1)

    2015-12-01

    Confidence Level Confidence Level of cost estimate for current APB: 55% This APB reflects cost and funding data based on the B-2 EHF Increment I SCP...This cost estimate was quantified at the Mean (~55%) confidence level . Total Quantity Quantity SAR Baseline Production Estimate Current APB...Production Estimate Econ Qty Sch Eng Est Oth Spt Total 33.624 -0.350 1.381 0.375 0.000 -6.075 0.000 -0.620 -5.289 28.335 Current SAR Baseline to Current

  2. Harnessing marketing automation for B2B content marketing

    Järvinen, Joel; Taiminen, Heini

    2016-01-01

    The growing importance of the Internet to B2B customer purchasing decisions has motivated B2B sellers to create digital content that leads potential buyers to interact with their company. This trend has engendered a new paradigm referred to as ‘content marketing.’ This study investigates the organizational processes for developing valuable and timely content to meet customer needs and for integrating content marketing with B2B selling processes. The results of this single case study demonstra...

  3. NMR relaxation rates and Knight shifts in MgB2 and AlB2: theory versus experiments

    Pavarini, E; Baek, S H; Suh, B J; Borsa, F; Bud'ko, S L; Canfield, P C

    2003-01-01

    We have performed 11 B NMR measurements in 11 B enriched MgB 2 powder sample in the normal phase. The Knight shift was accurately determined by using the magic angle spinning technique. Results for 11 B and 27 Al Knight shifts (K) and relaxation rates (1/T 1 ) are also reported for AlB 2 . The data show a dramatic decrease of both K and 1/T 1 for 11 B in AlB 2 with respect to MgB 2 . We compare experimental results with ab initio calculated NMR relaxation rates and Knight shifts. The experimental values for 1/T 1 and K are in most cases in good agreement with the theoretical results. We show that the decrease of K and 1/T 1 for 11 B is consistent with a drastic drop of the density of states at the boron site in AlB 2 with respect to MgB 2

  4. B2B or Not to Be: Does B2B E-Commerce Increase Labour Productivity?

    Bertschek, Irene; Fryges, Helmut; Kaiser, Ulrich

    2004-01-01

    We implement an endogeneous switching-regression model for labour productivity and firms' decision to use business-to-business (B2B) e-commerce. Our approach allows B2B usage to affect any parameter of the labour productivity equation and to properly take account of strategic complementarities between the input factors and B2B usage. Empirical evidence from 1,394 German firms shows that firms using B2B e-commerce have a significantly higher output elasticity with respect to ICT-investment and...

  5. Influence of TiB2 particles on machinability and machining parameter optimization of TiB2/Al MMCs

    Ruisong JIANG

    2018-01-01

    Full Text Available In situ formed TiB2 particle reinforced aluminum matrix composites (TiB2/Al MMCs have some extraordinary properties which make them be a promising material for high performance aero-engine blade. Due to the influence of TiB2 particles, the machinability is still a problem which restricts the application of TiB2/Al MMCs. In order to meet the industrial requirements, the influence of TiB2 particles on the machinability of TiB2/Al MMCs was investigated experimentally. Moreover, the optimal machining conditions for this kind of MMCs were investigated in this study. The major conclusions are: (1 the machining force of TiB2/Al MMCs is bigger than that of non-reinforced alloy and mainly controlled by feed rate; (2 the residual stress of TiB2/Al MMCs is compressive while that of non-reinforced alloy is nearly neutral; (3 the surface roughness of TiB2/Al MMCs is smaller than that of non-reinforced alloy under the same cutting speed, but reverse result was observed when the feed rate increased; (4 a multi-objective optimization model for surface roughness and material removal rate (MRR was established, and a set of optimal parameter combinations of the machining was obtained. The results show a great difference from SiC particle reinforced MMCs and provide a useful guide for a better control of machining process of this material.

  6. ORM-based semantics of B2B transactions.

    Balsters, H.; van Blommestein, F.; Meersman, R; Herrero, P; Dillon, T

    2009-01-01

    After widespread implementation of Enterprise Resource Planning and Personal Information Management, the next wave in the application of ICT is headed towards business to business (B2B) communication. B2B has a number of specific aspects, one of them being negotiation. This aspect has been largely

  7. 17 CFR 270.8b-2 - Definitions.

    2010-04-01

    ... such document is filed with such exchange. (j) Share. The term “share” means a share of stock in a... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Definitions. 270.8b-2 Section 270.8b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND...

  8. Hexagonal OsB2: Sintering, microstructure and mechanical properties

    Xie, Zhilin; Lugovy, Mykola; Orlovskaya, Nina; Graule, Thomas; Kuebler, Jakob; Mueller, Martin; Gao, Huili; Radovic, Miladin; Cullen, David A.

    2015-01-01

    Highlights: • ReB 2 -type hexagonal OsB 2 powder has been densified by spark plasma sintering. • The sintered OsB 2 contains ∼80 wt.% hexagonal and ∼20 wt.% orthorhombic phases. • The average grain size of the sintered OsB 2 sample was 0.56 ± 0.26 μm. • H = 31 ± 9 GPa and E = 574 ± 112 GPa measured by nanoindentation. - Abstract: The metastable high pressure ReB 2 -type hexagonal OsB 2 bulk ceramics was produced by spark plasma sintering. The phase composition, microstructure, and mechanical behavior of the sintered OsB 2 were studied by X-ray diffraction, optical microscopy, TEM, SEM, EDS, and nanoindentation. The produced ceramics was rather porous and contained a mixture of hexagonal (∼80 wt.%) and orthorhombic (∼20 wt.%) phases as identified by X-ray diffraction and EBSD analysis. Two boron-rich phases, which do not contain Os, were also identified by TEM and SEM/EDS analysis. Nanoindentation measurements yielded a hardness of 31 ± 9 GPa and Young’s modulus of 574 ± 112 GPa, indicating that the material is rather hard and very stiff; however, it is very prone to crack formation and propagation, which is indicative of a very brittle nature of this material. Improvements in the sintering regime are required in order to produce dense, homogeneous and single phase hexagonal OsB 2 bulk ceramics

  9. Multiband model for tunneling in MgB2 junctions

    Brinkman, Alexander; Golubov, Alexandre Avraamovitch; Rogalla, Horst; Dolgov, O.V.; Kortus, J.; Kong, Y.; Jepsen, O.; Andersen, O.K.

    2002-01-01

    A theoretical model for quasiparticle and Josephson tunneling in multiband superconductors is developed and applied to MgB2-based junctions. The gap functions in different bands in MgB2 are obtained from an extended Eliashberg formalism, using the results of band structure calculations. The

  10. B2B myynnin johtaminen ravintola-alalla

    Pajari, Katja

    2014-01-01

    Tämän opinnäytetyön tavoitteena oli selvittää, miten ravintola-alan yrityksissä johdetaan B2B myyntiä. Tarkoituksena oli kartoittaa, miten yrityksissä panostetaan B2B myyntiin ja sen johtamiseen sekä millä tavoin yritysmyyntiä johdetaan. Tutkimus pohjautuu opinnäytetyön tietoperustaan, jossa käsitellään B2B myyntiprosessia ja myynnin johtamista. Työssä käsitellään B2B myyntiä ja selvitetään myyntiprosessin eri vaiheita. Aihe on rajattu koskemaan nimenomaan johtamisen näkökulmaa B2B myynni...

  11. Tribology study on TiB2+WSi2 composite against WC

    Murthy, T. S. R. Ch.; Basha, M. M.; Sonber, J. K.; Singh, K.; Raju, K.; Sairam, K.; Nagaraj, A.; Majumdar, S.; Rao, G. V. S. Nageswara; Kain, Vivekanand

    2018-04-01

    Titanium diboride (TiB2) is one of the potential material for green energy applications such as neutron absorber in high temperature/advanced nuclear reactors, receiver materials for second generation concentrated solar power. We developed the process flow sheet for synthesis and consolidation of various series of TiB2 based materials in our laboratory. Amongst these, TiB2+WSi2 exhibited better sinterability and oxidation resistance properties. In the present work, tribology properties of TiB2+2.5%WSi2 composite was studied against WC-Co ball using different normal loads (5, 10 and 20 N) and frequencies (10, 15 Hz) under dry condition. Coefficient of friction (COF) and wear rate was measured at all test conditions. Wear mechanism was analyzed by microstructural characterization. It was found that COF is decreased from 0.46 to 0.36 with increasing load (5 to 20 N) at 15 Hz frequency; whereas at 10 Hz frequency COF is measured a constant average value of 0.49. The specific wear rate measured was minimum at 5 N load and 15 Hz frequency combination and was found to be 2.84×10-6 mm3/N m. The wear mechanisms identified during reciprocative sliding wear of composite were abrasion and surface tribo-oxidative reactions with delamination from tribo-zone.

  12. Magnetic and Moessbauer studies on GdCo3B2 and DyCo3B2

    Malik, S.K.; Umarji, A.M.; Shenoy, G.K.

    1984-10-01

    Magnetization and Moessbauer studies have been carried out on GdCo 3 B 2 and DyCo 3 B 2 . These compounds are magnetically ordered with Curie temperatures of 56 0 and 21 0 K respectively. The Co atoms are either nonmagnetic or carry a small moment in these compounds. The saturation moment of DyCo 3 B 2 at 5 0 K is smaller than the Dy 3+ free-ion value. From 161 Dy Moessbauer studies, the measured hyperfine magnetic field at the Dy site is also observed to be smaller than the free-ion value. 155 Gd Moessbauer measurements in GdCo 3 B 2 reveal the presence of large crystalline electric fields at the rare earth site. This causes the moment and the hyperfine field at the Dy site in DyCo 3 B 2 to be reduced from its free-ion value

  13. Defect structure of ultrafine MgB2 nanoparticles

    Bateni, Ali; Somer, Mehmet; Repp, Sergej; Erdem, Emre; Thomann, Ralf; Acar, Selçuk

    2014-01-01

    Defect structure of MgB 2 bulk and ultrafine particles, synthesized by solid state reaction route, have been investigated mainly by the aid of X-band electron paramagnetic resonance spectrometer. Two different amorphous Boron (B) precursors were used for the synthesis of MgB 2 , namely, boron 95 (purity 95%–97%, <1.5 μm) and nanoboron (purity >98.5%, <250 nm), which revealed bulk and nanosized MgB 2 , respectively. Scanning and transmission electron microscopy analysis demonstrate uniform and ultrafine morphology for nanosized MgB 2 in comparison with bulk MgB 2 . Powder X-ray diffraction data show that the concentration of the by-product MgO is significantly reduced when nanoboron is employed as precursor. It is observed that a significant average particle size reduction for MgB 2 can be achieved only by using B particles of micron or nano size. The origin and the role of defect centers were also investigated and the results proved that at nanoscale MgB 2 material contains Mg vacancies. Such vacancies influence the connectivity and the conductivity properties which are crucial for the superconductivity applications

  14. Digitaalisen markkinoinnin suunnitelma b2b-yritykselle

    Harhakoski, Oskari

    2011-01-01

    Työ käsittelee digitaalisen markkinoinnin suunnitelman tekemistä b2b-yritykselle. Tavoitteena oli kilpailuedun hankkiminen sosiaalisen median tehokkaalla hyödyntämisellä mark-kinoinnissa. Konkreettisemmin yritys halusi lisää näkyvyyttä ja myyntiä. Suunnitelman laatimisessa hyödynnettiin POST-menetelmää. Erityistä huomiota kiinnitettiin b2b-markkinoinnin eroihin b2c-markkinointiin verrattuna. Myös yrityksen toimiminen Suomen markkinoilla huomioitiin. Lisäksi analysoitiin kilpailijoita asia...

  15. Pulse laser irradiation into superconducting MgB2 detector

    Fujiwara, Daisuke; Miki, Shigehito; Satoh, Kazuo; Yotsuya, Tsutomu; Shimakage, Hisashi; Wang, Zhen; Okayasu, Satoru; Katagiri, Masaki; Machida, Masahiko; Kato, Masaru; Ishida, Takekazu

    2005-01-01

    We performed 20-ps pulse laser irradiation experiments on a MgB 2 neutron detector to know a thermal-relaxation process for designing a MgB 2 neutron detector. The membrane-type structured MgB 2 device was fabricated to minimize the heat capacity of sensing part of a detector as well as to enhance its sensitivity. We successfully observed a thermal-relaxation signal resulting from pulse laser irradiation by developing a detection circuit. The response time was faster than 1 μs, meaning that the detector would be capable of counting neutrons at a rate of more than 10 6 events per second

  16. Magnetic anisotropy of YNi2B2C single crystals

    Baran, M.; Gladczuk, L.; Gorecka, J.; Szymczak, H.; Szymczak, R.; Drzazga, Z.; Winiarska, H.

    1994-01-01

    Reversible and irreversible magnetization processes in YNi 2 B 2 C single crystal have been measured and analysed in terms of existing theories. Performed measurements suggest that anisotropy of the effective mass in YNi 2 B 2 C superconductor is rather small and similar to that observed in conventional superconductors. Effect of hydrostatic pressure on T c is shown to be typical of low-temperature superconductors. It is suggested that the layered structure of YNi 2 B 2 C has some effect on the irreversible magnetization processes observed in this superconductor. ((orig.))

  17. Remaining Sites Verification Package for the 126-B-2, 183-B Clearwells

    Dittmer, L.M.

    2007-01-01

    The 126-B-2, 183-B Clearwells were built as part of the 183-B Water Treatment Facility and are composed of 2 covered concrete reservoirs. The bulk of the water stored in the clearwells was used as process water to cool the 105-B Reactor and as a source of potable water. Residual conditions were determined to meet the remedial action objectives specified in the Remaining Sites ROD through an evaluation of the available process knowledge. The results of the evaluation do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also indicate that residual concentrations are protective of groundwater and the Columbia River.

  18. The role of TiB2 in strengthening TiB2 reinforced aluminium casting composites

    Chen, Z; Kang, H; Zhao, Y; Zheng, Y; Wang, T

    2016-01-01

    With an aim of developing high quality in situ TiB 2 reinforced aluminium foundry alloy based composites, the conventional direct synthesis method was modified into a two-step route. In step one we optimized the halide salt route to fabricate in situ TiB 2 particulate reinforced aluminium matrix composites and in step two we investigated the effects of the Al-5wt.% TiB 2 composite, as a “master composite”, on strengthening the practical foundry alloys. The in situ formed TiB 2 particles play two roles while strengthening the composites: (1) The grain refinement effect that improves the quality of the alloy matrix; and (2) The interactions between the hard particulates and the matrix add extra increment to the material strength. In different alloy systems, TiB 2 may play distinct roles in these two aspects (figure 1). Further analysis of the strengthening mechanisms shows that particle agglomeration behaviour during solidification is responsible for the latter one. The present work details the role of TiB 2 in strengthening TiB 2 reinforced aluminium casting composites. (paper)

  19. 26 CFR 1.403(b)-2 - Definitions.

    2010-04-01

    ...) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.403(b)-2 Definitions. (a) Application... 1450(b) of the Small Business Job Protection Act of 1996 (110 Stat. 1755, 1814) for special rules...

  20. Applying conceptual design to B2B sales negotiations

    Illi, Mikko; Ylirisku, Salu

    This paper addresses the challenge of perceiving B2B sales negotiation in a manner that would open up new possibilities for the improvement of the practice. B2B sales agents work under high pressure in developing relevant and appealing proposals when negotiating for a deal with a customer. The key...... problem that will be addressed is the building of understanding of a customer’s current needs and requirements, and then trying to devise an appropriate proposal to match these. The work of the sales agents in B2B sales negotiations is highly complex, as they need to understand both the modular machinery...... on the ways in which design sense making artefacts may drive also B2B sales agents’ work....

  1. B2B Models for DoD Acquisition

    Kamel, Magdi N

    2008-01-01

    A central vision of B2B e-commerce is that of an electronic marketplace that would bring suppliers together with major buyers of goods and services for the purpose of conducting "frictionless commerce...

  2. Novel high pressure hexagonal OsB2 by mechanochemistry

    Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

    2014-01-01

    Hexagonal OsB 2 , a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB 2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB 2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB 2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from −225 °C to 1050 °C. The hexagonal OsB 2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB 2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods. - Graphical abstract: High resolution transmission electron micrograph of hexagonal OsB 2 nanocrystallite with corresponding fast Fourier transform and simulated diffraction pattern. - Highlights: • Hexagonal OsB 2 has been synthesized for the first time by mechanochemical method. • Hexagonal OsB 2 crystallizes in P63/mmc space group (No. 194), a=2.916 Å and c=7.376 Å. • The hexagonal structure was confirmed by a transmission electron microscope. • No phase transformation was observed after being annealed at 1050 °C for 6 days. • 20 wt% of h-OsB 2 was transformed to o-OsB 2 after being sintered at 1500 °C for 5 min

  3. Thermal stability of hexagonal OsB2

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Andrew Payzant, E.

    2014-11-01

    The synthesis of novel hexagonal ReB2-type OsB2 ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of 10B and 11B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched 11B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB2 phase was the main product of synthesis with a small quantity of Os2B3 phase present after synthesis as an intermediate product. In the second case, where coarse crystalline 11B powder was used as a raw material, only Os2B3 boride was synthesized mechanochemically. The thermal stability of hexagonal OsB2 powder was studied by heating under argon up to 876 °C and cooling in vacuo down to -225 °C. During the heating, the sacrificial reaction 2OsB2+3O2→2Os+2B2O3 took place due to presence of O2/water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B2O3 and precipitation of Os metal out of the OsB2 lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB2 changed significantly. The shrinkage of the a lattice parameter was recorded in 276-426 °C temperature range upon heating, which was attributed to the removal of B atoms from the OsB2 lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O2, the hexagonal OsB2 ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice parameters and no phase changes detected during cooling.

  4. Combustion synthesis of AlB2-Al2O3 composite powders with AlB2 nanowire structures

    Yang, Pan; Xiao, Guoqing; Ding, Donghai; Ren, Yun; Yang, Shoulei; Lv, Lihua; Hou, Xing

    2018-05-01

    Using of Al and B2O3 powders as starting materials, and Mg-Al alloy as additives, AlB2-Al2O3 composite powders with AlB2 nanowire structures were successfully fabricated via combustion synthesis method in Ar atmosphere at a pressure of 1.5 MPa. The effect of different amount of Mg-Al alloy on the phase compositions and morphology of the combustion products was investigated. The results revealed that AlB2 and Al2O3 increased, whereas Al decreased with the content of Mg-Al alloy increasing. The impurities MgAl2O4 and AlB12 would exist in the sample with adding of 18 wt% Mg-Al alloy. Interestingly, FESEM/TEM/EDS results showed that AlB2 nanowires were observed in the products when the content of Mg-Al alloy is 6 wt% and 12 wt%. The more AlB2 nanowires can be found as the content of Mg-Al alloy increased. And the yield of AlB2 nanowires with the diameter of about 200 nanometers (nm) and the length up to several tens of micrometers (μm) in the combustion product is highest when the content of Mg-Al alloy is 12 wt%. The vapor, such as Mg-Al (g), B2O2 (g), AlO (g) and Al2O (g), produced during the process of combustion synthesis, reacted with each other to yield AlB2 nanowires by vapor-solid (VS) mechanism and the corresponding model was also proposed.

  5. B2B Models for DoD Acquisition

    2007-07-30

    product design, demand forecasting, asset management, and sales and marketing plans 35 Proctor & Gamble’s Private Industrial Network SOURCE: Laudon... B2B Models for DoD Acquisition 30 July 2007 by Magdi N. Kamel, Associate Professor Graduate School of Operational & Information Sciences...number. 1. REPORT DATE 30 JUL 2007 2. REPORT TYPE 3. DATES COVERED 00-00-2007 to 00-00-2007 4. TITLE AND SUBTITLE B2B Models for DoD

  6. Creating Competitive Advantage by Rethinking B2B Software Pricing

    Adelstrand, Carl; Brostedt, Emil

    2016-01-01

    The choice of pricing model for software products is a complex procedure due to the different characteristics compared to physical products. This thesis investigates and compares software pricing models in a B2B setting, and describes how KAM plays a role in executing a pricing model. The research has been conducted as an opportunist case study on Adebro, a technology company in the B2B sector. The thesis have come to the following conclusions, with data from interviews and literature: Perpet...

  7. Scope of Internal Marketing in B2B Companies

    Nigam, Niharika

    2007-01-01

    Abstract Previous studies have focused on "internal marketing" from services marketing perspective. There is, therefore, a great dearth of in-depth research on its application to other business types. This research attempts to find the scope of internal marketing in B2B companies. The purpose of this research is to closely examine the elements, their linkage, tools and applications of Internal marketing when applied to B2B settings. Internal marketing, the application of marketing managem...

  8. Il B2B e il paradigma dei costi di transazione (B2B and the Transaction Costs Paradigm

    Pierluigi Sabbatini

    2001-06-01

    Full Text Available Business to Business (B2B Internet commerce causes a significant contraction of transaction costs. According to the Coase paradigm, we would thus expect a deverticalization of the industry and broader scope for anonymous market mechanisms. In reality, such expectations are not fully borne out by the facts. When the industrial structure is concentrated the B2Bgenerally loses its independence, and is owned by the firms which most contribute to its development, e.g. the ones able to bring the liquidity to it. The B2B governance mechanism established by these firms gives hierarchical mechanisms a role which they do not usually play in extensive, anonymous markets.

  9. Novel high pressure hexagonal OsB2 by mechanochemistry

    Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

    2014-07-01

    Hexagonal OsB2, a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from -225 °C to 1050 °C. The hexagonal OsB2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods.

  10. Thermal stability of hexagonal OsB2

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Andrew Payzant, E.

    2014-01-01

    The synthesis of novel hexagonal ReB 2 -type OsB 2 ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of 10 B and 11 B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched 11 B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB 2 phase was the main product of synthesis with a small quantity of Os 2 B 3 phase present after synthesis as an intermediate product. In the second case, where coarse crystalline 11 B powder was used as a raw material, only Os 2 B 3 boride was synthesized mechanochemically. The thermal stability of hexagonal OsB 2 powder was studied by heating under argon up to 876 °C and cooling in vacuo down to −225 °C. During the heating, the sacrificial reaction 2OsB 2 +3O 2 →2Os+2B 2 O 3 took place due to presence of O 2 /water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B 2 O 3 and precipitation of Os metal out of the OsB 2 lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB 2 changed significantly. The shrinkage of the a lattice parameter was recorded in 276–426 °C temperature range upon heating, which was attributed to the removal of B atoms from the OsB 2 lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O 2 , the hexagonal OsB 2 ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice parameters and no phase changes detected during cooling. - Graphical abstract: The in situ high temperature XRD

  11. Fusion reactor materials

    Sethi, V.K.; Scholz, R.; Nolfi, F.V. Jr.; Turner, A.P.L.

    1980-01-01

    Data are given for each of the following areas: (1) effects of irradiation on fusion reactor materials, (2) hydrogen permeation and materials behavior in alloys, (3) carbon coatings for fusion applications, (4) surface damage of TiB 2 coatings under energetic D + and 4 He + irradiations, and (5) neutron dosimetry

  12. Lattice Thermal Conductivity of Ultra High Temperature Ceramics ZrB2 and HfB2 from Atomistic Simulations

    Lawson, John W.; Murray, Daw S.; Bauschlicher, Charles W., Jr.

    2011-01-01

    Atomistic Green-Kubo simulations are performed to evaluate the lattice thermal conductivity for single crystals of the ultra high temperature ceramics ZrB2 and HfB2 for a range of temperatures. Recently developed interatomic potentials are used for these simulations. Heat current correlation functions show rapid oscillations which can be identified with mixed metal-Boron optical phonon modes. Agreement with available experimental data is good.

  13. Pseudopotential approach to superconductivity in MgB2

    Sharma, K.S.; Bhargava, Nidhi; Jain, Ritu; Goyal, Varsha; Sharma, Ritu; Sharma, Smita

    2010-01-01

    Superconductivity in MgB 2 has been re-examined in BCS-Eliashberg framework by employing Mc-Millan's T c -equation and form factors of MgB 2 computed from the form factors of component metals (Model-I). The empty core model pseudopotential due to Ashcroft and random phase approximation form of dielectric screening due to Gellmann and Brueckner are used in the present work. An excellent agreement between the present values and other theoretically computed values of T c and with the relevant experimental data for MgB 2 confirms the validity of the present approach. The explicit dependence of λ and T c on the isotopic masses of Mg and B, as revealed from the present work, confirms the role of lattice vibrations in the superconducting behaviour of MgB 2 and the high value of T c in it may be attributed to the phonon mediated e-e interaction coupled with higher values of phonon frequencies due to light mass of B atoms. It has also been observed that the pseudo-atom model (Model-II) with appropriate choice of the potential parameter r c successfully explains high value of T c and isotope effect in MgB 2 , confirming the prominent role played by electron-phonon interaction in the high-T c superconductivity observed in MgB 2 . The isotope effect exponent α-values obtained from the two models are in complete agreement with each other and the present value α = 0.46 is also much closer to the BCS value of 0.5. Interaction strength N 0 V values obtained from the two models are also in perfect agreement with each other and the present value N 0 V = 0.48 suggests that MgB 2 is a strong coupling superconductor. (author)

  14. Dry cryomagnetic system with MgB2 coil

    Abin, D. A.; Mineev, N. A.; Osipov, M. A.; Pokrovskii, S. V.; Rudnev, I. A.

    2017-12-01

    MgB2 may be the future superconducting wire material for industrial magnets due to it’s higher operation temperature and potentially lower cost than low temperature superconductors (LTS) have. We designed a compact cryomagnetic system with the use of MgB2. The possibility of creating a magnet with a central field of 5 T from a commercial MgB2 wire by the “react and wound” method was investigated. The magnetic system is cooled by a cryocooler through a copper bus. The magnet has a warm bore diameter of 4 cm. The design of a magnet consisting of three concentric solenoids is proposed: an internal one of high-temperature superconductor (HTS), an average of MgB2, and an external of NbTi. The operating current of the system is 100 A. Two pairs of current leads are used. A separate pair of current leads for power supplying NbTi coil allows testing of MgB2 and HTS coils in an external field. The load curves for each of the magnets are calculated.

  15. Investigating the spectral anomaly with different reactor antineutrino experiments

    C. Buck

    2017-02-01

    Full Text Available The spectral shape of reactor antineutrinos measured in recent experiments shows anomalies in comparison to neutrino reference spectra. New precision measurements of the reactor neutrino spectra as well as more complete input in nuclear data bases are needed to resolve the observed discrepancies between models and experimental results. This article proposes the combination of experiments at reactors which are highly enriched in U235 with commercial reactors with typically lower enrichment to gain new insights into the origin of the anomalous neutrino spectrum. The presented method clarifies, if the spectral anomaly is either solely or not at all related to the predicted U235 spectrum. Considering the current improvements of the energy scale uncertainty of present-day experiments, a significance of three sigma and above can be reached. As an example, we discuss the option of a direct comparison of the measured shape in the currently running Double Chooz near detector and the upcoming Stereo experiment. A quantitative feasibility study emphasizes that a precise understanding of the energy scale systematics is a crucial prerequisite in recent and next generation experiments investigating the spectral anomaly.

  16. Studies on the intestinal absorption of vitamin B2

    Yamaguchi, Keiko; Moriwaki, Chiaki

    1978-01-01

    The intestinal absorption of vitamin B 2 was studied by in situ mesenteric perfusion system. Free form riboflavin (FR), FMN and FAD (1 mg each) were injected into the ligated jejunum of rat which was infused Krebs Ringer bicarbonate solution from the superior mesenteric artery. Perfusate was recovered from the mesenteric vein and the recoveries of the total riboflavin during 120 min after the administration of these 3 types vitamin B 2 were 1.0, 1.5 and 2.8%, respectively. Furthermore, riboflavin and its esters were detected in the perfusates from 14 C-FR and 14 C-FAD given rats. There was a considerable amount of labeled substance which was not vitamin B 2 derivatives in the radiopaperchromatogram of the perfusate of 14 C-FR dosed rats, and it is suggested that a portion of riboflavin is decomposed in the process of absorption. (auth.)

  17. B2B-myynnin nykytila ja haasteet Suomessa

    Ylimaula, Jukka

    2014-01-01

    Tämä opinnäytetyö tutki B2B-myynnin nykytilaa valituissa suomalaisissa yrityksissä. Tutkimuksen tavoite oli selvittää myyntijohdon mielestä B2B-myynnissä tärkeitä asioita ja hahmottaa tapaa, jolla organisaatio toimii yhteistyössä myynnissä. Näin teemojen pohjalta opinnäytetyö pyrki muodostamaan ajankuvan suomalaisesta B2B-myynnistä. Opinnäytetyö muodostuu teoriaosasta ja empiirisestä osasta. Teoreettinen osuus tutkii myyntiä sekä myyjän että ostajan näkökulmasta. Myös asiakassuhteita ja m...

  18. Chemical vapor deposition of TiB2 on graphite

    Pierson, H.O.; Randich, E.; Mattox, D.M.

    1978-01-01

    This study is an experimental investigation of the coating of graphite with TiB 2 by chemical vapor deposition (CVD) using the hydrogen reduction of BCl 3 and TiCl 4 at 925 0 C and 1 atm. Reasonable matching of the thermal expansion of TiB 2 and graphite was necessary to eliminate cracking. A suitable graphite was POCO DFP-1. Adhesion was improved by having a slightly rough graphite surface. Heat treatment at 2000 0 C and above resulted in a certain degree of diffusion. No melting or solid phases other than TiB 2 and graphite were detected up to 2400 0 C. The coatings showed no failure when repeatedly submitted to an electron beam pulse of 2 KW/cm 2 for 0.8 sec

  19. ORM-Based Semantics of B2B Transactions

    Balsters, H.; van Blommestein, F.

    After widespread implementation of Enterprise Resource Planning and Personal Information Management, the next wave in the application of ICT is headed towards business to business (B2B) communication. B2B has a number of specific aspects, one of them being negotiation. This aspect has been largely neglected by present implementations of standard EDI- or XML-messaging and by B2B webservice implementations. In this paper a precise model is given of the negotiation process. The requirements of a potential Buyer and the offer of a potential Seller are matched and, if the negotiation is successful, a contract is concluded. The negotiation process model is represented in ORM, extended with dynamic constraints. Our model may be implemented in the databases of the trading partners and in message- or service definitions.

  20. Densification and properties of HfB2 based materials

    Sonber, J.K.; Ch Murthy, T.S.R.; Bedse, R.D.; Subramanian, C.; Kumar, Sunil; Fotedar, R.K.; Krishnamurthy, N.; Suri, A.K.

    2011-01-01

    This paper presents the results of investigation carried out on densification and properties of HfB 2 based materials. Densification study of HfB 2 with and without sinter additive was carried out by hot pressing. TiSi 2 and CrSi 2 were used as sinter additive. Monolithic HfB 2 was densified to only 80%ρ th at 1850 deg C with a pressure of 35 MPa. Addition of 10 wt% TiSi 2 resulted in a density of 95% TD at a relatively low temperature of 1650 deg C and a low pressure of 20 MPa. Addition of 10% CrSi 2 resulted in a density of 99% TD at the same operating conditions. All the samples were characterized by SEM/EDS and mechanical property measurement. (author)

  1. Electromagnetic densification of MgB2/Cu wires

    Woźniak, M; Glowacki, B A

    2014-01-01

    Electromagnetic compaction of in situ MgB 2 /Cu wire has been achieved using a custom-built 200 J device. The monofilament core packing density was increased by 8% and up to 31% for unreacted and reacted wires respectively. The higher density of the MgB 2 core resulted in a critical current density increase of up to 75% in comparison to that for cold-drawn-only wire. Applying this treatment to a wire with Cu powder additions to the core and with an optimized heat treatment resulted in one of the highest ever reported values of J c for MgB 2 /Cu wires of 6.83 × 10 3  A cm −2 at 4.2 K and 6 T. (paper)

  2. Vitamin B2 (riboflavin content in cereal products

    Soňa Škrovánková

    2010-01-01

    Full Text Available Vitamin B2 (riboflavin is a water-soluble essential vitamin. Nowadays an increased risk for riboflavin deficiency may be seen in people on special diets (diabetes mellitus, smokers or heavy alcohol drinkers. In the Czech diet the main sources of the vitamin intake are milk and dairy products followed by cereals and meat. Cereals are good source of this vitamin as it is widely and regularly consumed in different forms. Analyses of the vitamin B2 content in different types of cereal products (flours, breads, pastries, breakfast cereals, cooked pasta of Czech origin using HPLC with reversed phase and UV detection were done. The vitamin B2 content of chosen cereal products decreased in this progression: enriched wholemeal breakfast cereals (the best source of the vitamin, enriched wheat flours, breads – rye and wholemeal wheat breads, whole wheat and spelt flours, wheat bread, cooked whole wheat and rye spaghetti, wheat and multigrain pastries and finally scoured wheat flours.

  3. MgB2 superconducting wires basics and applications

    2016-01-01

    The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods. A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.

  4. A new superhard material: Osmium diboride OsB 2

    Hebbache, M.; Stuparević, L.; Živković, D.

    2006-08-01

    Superhard materials have many industrial applications, wherever resistance to abrasion and wear are important. The synthesis of new superhard materials is one of the great challenges to scientists. We re-examined the phase diagram of the binary osmium-boron system and confirmed the existence of two hexagonal phases, OsB 1.1, Os 2B 3, and an orthorhombic phase, OsB 2. Almost nothing is known about the physical properties of osmium borides. Microhardness measurements show that OsB 2 is extremely hard. Ab initio calculations show that this is due to formation of covalent bonds between boron atoms. OsB 2 is also a low compressibility material. It can be used as hard coating.

  5. Construction of the irreducibles of B(2, 2)

    Melas, Evangelos

    2006-01-01

    The ordinary Bondi-Metzner-Sachs (BMS) group B is the common asymptotic symmetry group of all radiating, asymptotically flat, Lorentzian spacetimes. As such, B is the best candidate for the universal symmetry group of general relativity. However, in studying quantum gravity, spacetimes with signatures other than the usual Lorentzian one and complex spacetimes are frequently considered. Generalizations of B appropriate to these other signatures have been defined earlier. In particular, the generalization B(2, 2) appropriate to the ultrahyperbolic signature (+, +, -, -) has been described in detail, and the study of its irreducible unitary representations (IRs) of B(2, 2) has been initiated. The infinite little groups have been given explicitly, but the finite little groups have only been partially described. This study is completed by describing in detail the finite little groups and by giving all the necessary information in order to construct the IRs of B(2, 2) in all cases

  6. B2B-myyntiprosessi : case: Yritys X

    Lamppu, Samuli

    2017-01-01

    Opinnäytetyön aiheena on B2B-myyntiprosessi yrityksessä x. Työn tavoitteena on kartoittaa yrityksen B2B-myyntiprosessin nykytila, tunnistaa mahdolliset ongelma-alueet ja tehdä tämän perusteella ehdotukset toimenpiteistä prosessin parantamiseksi. Työ tehdään suomalaisen PK-yrityksen toimeksiannosta. Opinnäytetyön taustalla on oma urani yrityksen yritysmyynnissä, ja työni kautta tunnistamani haasteet sekä mahdollisuudet, joita hyödyntämällä yritys voisi kehittää myyntitoimintaansa. Yritykse...

  7. Cosima B2B - Sales Automation for E-Procurement

    Kießling, Werner (Prof. Dr.); Fischer, Stefan; Döring, Sven

    2006-01-01

    E-procurement is one of the fastest growing application areas for e-commerce. Though B2B transaction costs could be reduced recently by establishing XML based standards for electronic product catalogs and data interchange, B2B sales costs are still high due to the amount of human interaction. For the first time we present a fully automated electronic sales agent for e-procurement portals. The key technologies for this breakthrough are based on preferences modeled as strict partial orders, ena...

  8. How has IT impacted the B2B sales process?

    Bjørnstad, Julia Jemli

    2017-01-01

    B2B sales role plays a major role in driving the economy, and this industry has been experiencing major changes over the year with the advances in technology which allow for more cost savings and driving for more efficient ways of conducting sales operations. The objective of this exploratory qualitative research paper was to raise interest in the role technology plays in the B2B sales process today from the salesperson’s view point. It was further partly built on previous rese...

  9. B2B Integration in Global Supply Chains

    Schubert, Petra; Legner, Christine

    2011-01-01

    The competitiveness of businesses is increasingly dependent on their electronic networks with customers, suppliers, and partners. While the strategic and operational impact of external integration and IOS adoption has been extensively studied, much less attention has been paid to the organizational...... and technical design of electronic relationships. The objective of our longitudinal research project is the development of a framework for understanding and explaining B2B integration. Drawing on existing literature and empirical cases we present a reference model (a classification scheme for B2B Integration...

  10. Il B2B e il paradigma dei costi di transazione (B2B and the Transaction Costs Paradigm

    Pierluigi Sabbatini

    2012-04-01

    Full Text Available Business to Business (B2B Internet commerce causes a significant contraction of transaction costs. According to the Coase paradigm, we would thus expect a deverticalization of the industry and broader scope for anonymous market mechanisms. In reality, such expectations are not fully borne out by the facts. When the industrial structure is concentrated the B2Bgenerally loses its independence, and is owned by the firms which most contribute to its development, e.g. the ones able to bring the liquidity to it. The B2B governance mechanism established by these firms gives hierarchical mechanisms a role which they do not usually play in extensive, anonymous markets.         JEL Codes: D23, L86Keywords: Cost, Transaction Costs, Transactions

  11. Investigation of TaC–TaB2 ceramic composites

    ture and the mechanical properties of the composites were investigated. The results .... 300 nm. Jingangzuan in the TaC/TaB2 composites SPS for 10 min at different temperatures are .... [1] Liu L, Yea F, Hea X and Zhoua Y 2011 Mater. Chem.

  12. Canonical realizations of B2 approximately C2 Lie algebras

    Iosifescu, M.; Scutaru, H.

    1982-12-01

    Canonical realizations associated to subrepresentations of ad x ad, for B 2 apppoximately C 2 semisimple Lie algebras, have been determined. An algebraic foundation has been obtained for the constraints satisfied by the dinamical variables of the classical limit of the generalized Helium problem. (authors)

  13. Selenidation of epitaxial silicene on ZrB2

    Wiggers, F. B.; Yamada-Takamura, Y.; Kovalgin, A. Y.; de Jong, M. P.

    2018-01-01

    The deposition of elemental Se on epitaxial silicene on ZrB2 thin films was investigated with synchrotron-based core-level photoelectron spectroscopy and low-energy electron diffraction. The deposition of Se at room temperature caused the appearance of Si 2p peaks with chemical shifts of n × 0.51 ±

  14. Structural, electronic and magnetic properties of MnB2

    5Hassan II Academy of Science and Technology, Rabat, Morocco ... Abstract. The self-consistent ab-initio calculations, based on density functional theory approach and using the full ... The exchange interactions between the magnetic atoms Mn–Mn in MnB2 are ... involved, and on the local environment of the transition-.

  15. Microwave absorption studies of MgB2 superconductor

    band (9–. 10 GHz) spectrometer. Both polycrystalline pellet and single-grain MgB2, having nearly the same Tc (∼ 39 K) and same size (3×2×1 mm3), were used in the present investigations. Low field modulated microwave absorption signals ...

  16. Electronic structure and superconductivity of MgB 2

    Results of ab initio electronic structure calculations on the compound, MgB2, using the FPLAPW method employing GGA for the exchange–correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with ...

  17. Intelligent Information Integration in B2B Electronic Commerce

    Fensel, Dieter; Omelayenko, Borys; Ding, Ying; Klein, Michel; Flett, Alan; Schulten, Ellen; Botquin, Guy; Brown, Mike; Dabiri, Gloria

    2002-01-01

    Internet and web technology penetrates many aspects of our daily life. Its importance as a medium for business transactions will grow exponentially during the next few years. In terms of the involved market volume, the B2B area will hereby be the most interesting area. Also, it will be the place,

  18. Superconducting state in (W, Ta)5SiB2

    Fukuma, M.; Kawashima, K.; Akimitsu, J.

    We characterize the superconducting state in a boro-silicide (W, Ta)5SiB2, with Tc of 6.5 K by means of magnetization, electrical resistivity, and specific heat measurements. As x increased, the transition temperature Tc abruptly enhances from 5.8 to 6.5 K. The magnetization versus magnetic field (M-H) curve indicated that (W, Ta)5SiB2 was a conventional type-II superconductor. The estimated lower critical field Hc1(0) and upper critical field Hc2(T) are about 121 Oe and 14.7 kOe, respectively. The penetration depth λ(0) and coherence length ξ(0) are calculated to be approximately 369 and 14.9 nm, respectively, using Ginzburg-Landau (GL) equations. Specific heat data shows the superconductivity in W4.5Ta0.5SiB2 belongs to a week-coupling BCS superconductor. Finally, we discuss the increasing of Tc in of (W, Ta)5SiB2 system.

  19. Preparation and characterization of MgB2 superconductor

    2Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India. Abstract. The MgB2 superconductor, synthesized using solid-state and liquid-phase sintering methods, have been characterized for various properties. The upper critical field, irreversibility line and critical current density have been ...

  20. 26 CFR 48.4161(b)-2 - Meaning of terms.

    2010-04-01

    ... EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Sporting Goods § 48.4161(b)-2 Meaning of terms. (a... with the particular type of arrow shaft. (b) Parts and accessories—(1) In general. “Parts and... attachment to, a bow or arrow of the type described in section 4161(b)(1) and paragraph (a) of this section...

  1. Marketing-sales interface configurations in B2B firms

    Biemans, Wim G.; Brencic, Maja Makovec; Malshe, Avinash; Makovec Brenciv, M.

    As the body of knowledge on marketing-sales interface expands, there is a greater need to investigate the specific aspects of marketing-sales configurations in B2B firms. Using a qualitative methodology and interview data collected from over 100 sales and marketing professionals from the US, The

  2. Development of New B2B Venture Corporate Brand Identity

    Törmälä, Minna; Gyrd-Jones, Richard I.

    2017-01-01

    of interviews and archival data generated during a three-year period to examine the development of corporate brand over time. This study shows that the development of corporate brand identity and the context of the development of new B2B venture are closely intertwined processes and provides a framework...

  3. Microwave absorption studies of MgB 2 superconductor

    Microwave absorption studies have been carried out on MgB2 superconductor using a standard X-band EPR spectrometer. The modulated low-field microwave absorption signals recorded for polycrystalline (grain size ∼ 10m) samples suggested the absence of weak-link character. The field dependent direct microwave ...

  4. Itinerant magnetism in CeRh3B2

    Eriksson, Olle; Johansson, Börje; Brooks, M. S. S.

    1989-01-01

    Spin-polarized energy-band calculations, including spin-orbit coupling in the band Hamiltonian, have been performed on CeRh3B2. Good agreement is obtained between theory and experiment concerning the magnetic moment. It is also found that the magnetic moment varies strongly with volume and from...

  5. Insulator layer formation in MgB2 SIS junctions

    Shimakage, H.; Tsujimoto, K.; Wang, Z.; Tonouchi, M.

    2005-01-01

    The dependence of current-voltage characteristics on thin film deposition conditions was investigated using MgB 2 /AlN/NbN SIS junctions. By increasing the substrate temperature in AlN insulator deposition, the current density decreased and the normal resistance increased. The results indicated that an additional insulator layer between the MgB 2 and AlN formed, either before or during the AlN deposition. The thickness of the additional insulator layer was increased with an increase in the AlN deposition temperature. From the dependence of current density on the thickness of AlN in low temperature depositions, the thickness of the additional insulator layer was estimated to be 1-1.5 nm when the AlN insulator was deposited from 0.14 to 0.7 nm. Moreover, with the current density of MgB 2 /AlN/MgB 2 SIS junctions, further insulator layer formation was confirmed

  6. E-Business Models in B2B: Process Based Categorization and Analysis of B2B Models

    Mahesh S. Raisinghani; Turan Melemez; Lijie Zou; Chris Paslowski; Irma Kimvidze; Susanne Taha; Klaus Simons

    2005-01-01

    The business models in business-to-business (B2B) e-commerce and their effectiveness have been a major topic of research in recent years. Due to the variety of existing models, it seems difficult to find a widely accepted categorization that can be analyzed and assessed. An in-depth study that provides a process-based approach to B2B e-commerce is presented and illustrated with examples from industry. A comparative examination of both the buy and the sell side based on a process-related appro...

  7. Directional crystallization of B4C-NbB2 and B4C-MoB2 eutectic compositions

    Paderno, Varvara; Paderno, Y.B.; Filippov, Vladimir; Liashchenko, Alfred

    2004-01-01

    We studied the directional crystallization of different compositions in B 4 C-NbB 2 and B 4 C-MoB 2 systems. The eutectic compositions for both systems are evaluated. It is shown that in the first system the rod-like eutectic structure is formed, in second, the 'Chinese hieroglyphics'. In both cases high hardness and high microplasticity are observed, which are much more than for individual component phases. These compositions may be considered as a new kind of self-strengthening composite materials

  8. OsB 2 and RuB 2, ultra-incompressible, hard materials: First-principles electronic structure calculations

    Chiodo, S.; Gotsis, H. J.; Russo, N.; Sicilia, E.

    2006-07-01

    Recently it has been reported that osmium diboride has an unusually large bulk modulus combined with high hardness, and consequently is a most interesting candidate as an ultra-incompressible and hard material. The electronic and structural properties of the transition metal diborides OsB 2 and RuB 2 have been calculated within the local density approximation (LDA). It is shown that the high hardness is the result of covalent bonding between transition metal d states and boron p states in the orthorhombic structure.

  9. Thermoelastic properties of ScB2, TiB2, YB4 and HoB4

    Waskowska, A.; Gerward, L.; Staun Olsen, J.

    2011-01-01

    (4)GPa). No pressure-induced phase transformations are observed in any of the above borides up to about 20GPa. A continuous temperature-driven orthorhombic distortion is observed for HoB4 below 285K. Values of the thermal expansion coefficient are reported for ScB2 and HoB4 at 293, 200 and 100K...

  10. Electronic and elastic properties of new semiconducting oP12-type RuB2 and OsB2

    Hao Xianfeng; Xu Yuanhui; Gao Faming

    2011-01-01

    Using first-principles total energy calculations we investigate the structural, elastic and electronic properties of new hypothetical oP 12 -type phase RuB 2 and OsB 2 . The calculations indicate that the oP 12 -type phase RuB 2 and OsB 2 are thermodynamically and mechanically stable. Remarkably, the new phases RuB 2 and OsB 2 are predicted to be semiconductors, and the appearance of band gaps is ascribed to the enhanced B-B covalent hybridization. Compared to metallic oP 6 -type RuB 2 and OsB 2 phases, the new phases possess similar mechanical properties and hardness. The combination of the probability of tunable electronic properties, strong stiffness and high hardness make RuB 2 and OsB 2 attractive and interesting for advanced applications.

  11. Electronic and elastic properties of new semiconducting oP(12)-type RuB(2) and OsB(2).

    Hao, Xianfeng; Xu, Yuanhui; Gao, Faming

    2011-03-30

    Using first-principles total energy calculations we investigate the structural, elastic and electronic properties of new hypothetical oP(12)-type phase RuB(2) and OsB(2). The calculations indicate that the oP(12)-type phase RuB(2) and OsB(2) are thermodynamically and mechanically stable. Remarkably, the new phases RuB(2) and OsB(2) are predicted to be semiconductors, and the appearance of band gaps is ascribed to the enhanced B-B covalent hybridization. Compared to metallic oP(6)-type RuB(2) and OsB(2) phases, the new phases possess similar mechanical properties and hardness. The combination of the probability of tunable electronic properties, strong stiffness and high hardness make RuB(2) and OsB(2) attractive and interesting for advanced applications. © 2011 IOP Publishing Ltd

  12. Active Protection of an MgB2 Test Coil

    Park, Dong Keun; Hahn, Seungyong; Bascuñán, Juan; Iwasa, Yukikazu

    2011-01-01

    This paper presents results of a study, experimental and computational, of a detect-and-activate-the-heater protection technique applied to a magnesium diboride (MgB2) test coil operated in semi-persistent mode. The test coil with a winding ID of 25 cm and wound with ~500-m long reacted MgB2 wire was operated at 4.2 K immersed in a bath of liquid helium. In this active technique, upon the initiation of a “hot spot” of a length ~10 cm, induced by a “quench heater,” a “protection heater” (PH) of ~600-cm long planted within the test coil is activated. The normal zone created by the PH is large enough to absorb the test coil’s entire initial stored energy and still keeps the peak temperature within the winding below ~260 K. PMID:22081754

  13. Observation of pseudogap in MgB2

    Patil, S.; Medicherla, V. R. R.; Ali, Khadiza; Singh, R. S.; Manfrinetti, P.; Wrubl, F.; Dhar, S. K.; Maiti, Kalobaran

    2017-11-01

    We investigate the electronic structure of a specially prepared highly dense conventional high temperature superconductor, MgB2, employing high resolution photoemission spectroscopy. The spectral evolution close to the Fermi energy is commensurate to BCS descriptions as expected. However, the spectra in the wider energy range reveal the emergence of a pseudogap much above the superconducting transition temperature indicating an apparent departure from the BCS scenario. The energy scale of the pseudogap is comparable to the energy of the E2g phonon mode responsible for superconductivity in MgB2 and the pseudogap can be attributed to the effect of electron-phonon coupling on the electronic structure. These results reveal a scenario of the emergence of the superconducting gap within an electron-phonon coupling induced pseudogap and have significant implications in the study of high temperature superconductors.

  14. Investigation of pinning in MgB2 superconductors

    Mohammad, S.; Reissner, M.; Steiner, W.; Bauer, E.; Giovannini, M.

    2006-01-01

    Full text: The pinning behaviour of bulk MgB 2 superconductors is peculiar in many respects. Pinning seems to be stronger than in classical high T C materials and there seems to be no weak link problem in these compounds, giving hope to produce bulk samples and wires with current densities appropriate for technical applications. But, although many studies concerning the pinning behaviour in this compound appeared in recent years, the results are still contradictory. In the present work we present results of an investigation of the pinning behaviour by magnetic relaxation measurements of three MgB 2 samples: a pure one, a sample with 8 at% Al substitution and a sample with 10 wt% of SiC admixture. A comparison of different analyses methods is given. (author)

  15. COSIMA B2B - sales automation for e-procurement

    Döring, Sven

    2004-01-01

    COSIMA B2B - sales automation for e-procurement / W. Kießling, S. Fischer, S. Döring. - In: International Conference on E-Commerce Technology : Proceedings / IEEE International Conference on E-Commerce Technology, CEC 2004 : 6 - 9 July 2004, San Diego, California / ed. by Martin Bichler ... - Los Alamitos, Calif. [u.a.] : IEEE Computer Society, 2004. - S. 59-68

  16. Customer satisfaction in B2B cloud services

    Turunen, Helinä

    2013-01-01

    Tutkimuksen tavoitteena on kirjallisuuskatsauksen kautta esitellä B2B-pilvipalveluiden asiakastyytyväisyyteen vaikuttavia seikkoja, ja kuinka näitä seikkoja tulisi ottaa huomioon asiakastyytyväisyyden parantamisessa. Tässä tutkimuksessa verkkopohjaiseen liiketoimintaan liittyvää asiakastyytyväisyyden tutkimusta käytettiin pohjana etsiessä asiakastyytyväisyyteen vaikuttavia seikkoja pilvipalveluissa. Tutkimuksessa vertaillaan asiakastyytyväisyyteen vaikuttavia seikkoja vertailemalla tyytyväisy...

  17. Mass Customized Technical Textiles in the B2B Sector

    Gebhardt, R.; Barteld, M.; Grafmüller, L.; Mosig, T.; Weiß, M.

    2017-10-01

    Mass Customization is a great opportunity for textile companies for both staying competitive in high-wage countries and offering inexpensive, customized products. Within the area of Technical Textiles, this study focuses on the B2B sector and shows the status quo, potentials and strengths. Both management and technological issues are addressed. For the former, business models and the value co-creation process are dealt with, for the latter, the focus is on modelling.

  18. Superconducting and Normal State Properties of OsB2*

    Singh, Yogesh; Niazi, A.; Zong, X.; Suh, B. J.; Vannette, M. W.; Prozorov, R.; Johnston, D. C.

    2007-03-01

    OsB2 is a layered superhard metallic material that was found to superconduct below Tc= 2.1 K.^1 We report the first detailed measurements of the static and dynamic magnetic susceptibilities χ, electrical resistivity, heat capacity Cp, penetration depth, and ^11B NMR on OsB2 to characterize its superconducting and normal state properties. The results confirm that OsB2 is a bulk superconductor below Tc= 2.1 K@. Its properties can be described by a close to weak-coupling s-wave BCS model with an electron-phonon coupling constant λ= 0.4--0.5, δ(0)/(kBTc) 1.9, a small Ginzburg-Landau parameter κ of order 5 or less, and a small zero-temperature critical magnetic field of roughly 500 Oe. The ^11B NMR measurements in the normal state show a nuclear spin-lattice relaxation time T1= 2.1 s at room temperature and a Korringa law with T1T = 610 s.K at lower T, and a correspondingly small T-independent Knight shift. These results indicate a small s character of the conduction electron wave function at the B site at the Fermi level. Our results will be compared to corresponding data for MgB2.1. J. K. Vandenberg et al., Mater. Res. Bull. 10, 889 (1975).^*Supported by the USDOE under Contract No. W-7405-Eng-82. Permanent address: Dept. Phys., The Catholic Univ. Korea.

  19. $1$-string $B_2$-VPG representation of planar graphs

    Therese Biedl

    2016-09-01

    Full Text Available In this paper, we prove that every planar graph has a 1-string $B_2$-VPG representation—a string representation using paths in a rectangular grid that contain at most two bends. Furthermore, two paths representing vertices $u,v$ intersect precisely once whenever there is an edge between $u$ and $v$. We also show that only a subset of the possible curve shapes is necessary to represent $4$-connected planar graphs.

  20. Agent-based services for B2B electronic commerce

    Fong, Elizabeth; Ivezic, Nenad; Rhodes, Tom; Peng, Yun

    2000-12-01

    The potential of agent-based systems has not been realized yet, in part, because of the lack of understanding of how the agent technology supports industrial needs and emerging standards. The area of business-to-business electronic commerce (b2b e-commerce) is one of the most rapidly developing sectors of industry with huge impact on manufacturing practices. In this paper, we investigate the current state of agent technology and the feasibility of applying agent-based computing to b2b e-commerce in the circuit board manufacturing sector. We identify critical tasks and opportunities in the b2b e-commerce area where agent-based services can best be deployed. We describe an implemented agent-based prototype system to facilitate the bidding process for printed circuit board manufacturing and assembly. These activities are taking place within the Internet Commerce for Manufacturing (ICM) project, the NIST- sponsored project working with industry to create an environment where small manufacturers of mechanical and electronic components may participate competitively in virtual enterprises that manufacture printed circuit assemblies.

  1. Strength anomaly in B2 FeAl single crystals

    Yoshimi, K.; Hanada, S.; Yoo, M.H. [Oak Ridge National Lab., TN (United States); Matsumoto, N. [Tohoku Univ. (Japan). Graduate School

    1994-12-31

    Strength and deformation microstructure of B2 Fe-39 and 48%Al single crystals (composition given in atomic percent), which were fully annealed to remove frozen-in vacancies, have been investigated at temperatures between room temperature and 1073K. The hardness of as-homogenized Fe-48Al is higher than that of as-homogenized Fe-39Al while after additional annealing at 698K the hardness of Fe-48Al becomes lower than that of Fe-39Al. Fe-39Al single crystals slowly cooled after homogenizing at a high temperature were deformed in compression as a function of temperature and crystal orientation. A peak of yield strength appears around 0.5T{sub m} (T{sub m} = melting temperature). The orientation dependence of the critical resolved shear stress does not obey Schmid`s law even at room temperature and is quite different from that of b.c.c. metals and B2 intermetallics at low temperatures. At the peak temperature slip transition from <111>-type to <001>-type is found to occur macroscopically and microscopically, while it is observed in TEM that some of the [111] dislocations decompose into [101] and [010] on the (1096I) plane below the peak temperature. The physical sources for the positive temperature dependence of yield stress of B2 FeAl are discussed based on the obtained results.

  2. MgB2 and Mg1-xAlxB2 single crystals: high pressure growth and physical properties

    Karpinski, J.; Kazakov, S.M.; Jun, J.; Zhigadlo, N.D.; Angst, M.; Puzniak, R.; Wisniewski, A.

    2004-01-01

    Single crystals of MgB 2 have been grown with a high pressure cubic anvil technique. They grow via the peritectic decomposition of the MgNB 9 ternary nitride. The crystals are of a size up to 2 x 1 x 0.1 mm 3 with a weight up to 230 μg. Typically they have transition temperatures between 38 and 38.6 K with a width of 0.3-0.5 K. Investigations of the P-T phase diagram prove that the MgB 2 phase is stable at least up to 2190 deg. C at high hydrostatic pressure in the presence of Mg vapor under high pressure. Substitution of aluminum for magnesium in single crystals leads to stepwise decrease of T c . This indicates a possible appearance of superstructures or phases with different T c 's. The upper critical field decreases with Al doping

  3. Precipitation method for barium metaborate (BaB2O4) synthesis from borax solution

    Akşener, Eymen; Figen, Aysel Kantürk; Pişkin, Sabriye

    2013-01-01

    In this study, barium metaborate (BaB 2 O 4 , BMB) synthesis from the borax solution was carried out. BMB currently is used in production of ceramic glazes, luminophors, oxide cathodes as well as additives to pigments for aqueous emulsion paints and also β−BaB 2 O 4 single crystals are the best candidate for fabrication of solid-state UV lasers operating at a wavelength of 200 nm due to excellent nonlinear optical properties. In the present study, synthesis was carried out from the borax solution (Na 2 B 4 O 7⋅ 10H 2 O, BDH) and barium chloride (BaCI 2⋅ 2H 2 O, Ba) in the glass-batch reactor with stirring. The effect of, times (5-15 min), molar ratio [stoich.ration (1.0:2.0), 1.25:2.0, 1.5:2.0, 2.5:2:0, 3.0:2.0, 3.5:2.0,4.0:2.0, 5.0:2.0] and also crystallization time (2-6 hour) on the BMB yield (%) was investigated at 80 °C reaction temperature. It is found that, BMB precipitation synthesis with 90 % yield can be performed from 0.50 molar ration (BDH:Ba), under 80 °C, 15 minute, and 6 hours crystallization time. The structural properties of BMB powders were characterized by using XRD, FT-IR and DTA-TG instrumental analysis technique

  4. Precipitation method for barium metaborate (BaB2O4) synthesis from borax solution

    Akşener, Eymen; Figen, Aysel Kantürk; Pişkin, Sabriye

    2013-12-01

    In this study, barium metaborate (BaB2O4, BMB) synthesis from the borax solution was carried out. BMB currently is used in production of ceramic glazes, luminophors, oxide cathodes as well as additives to pigments for aqueous emulsion paints and also β-BaB2O4 single crystals are the best candidate for fabrication of solid-state UV lasers operating at a wavelength of 200 nm due to excellent nonlinear optical properties. In the present study, synthesis was carried out from the borax solution (Na2B4O7ṡ10H2O, BDH) and barium chloride (BaCI2ṡ2H2O, Ba) in the glass-batch reactor with stirring. The effect of, times (5-15 min), molar ratio [stoich.ration (1.0:2.0), 1.25:2.0, 1.5:2.0, 2.5:2:0, 3.0:2.0, 3.5:2.0,4.0:2.0, 5.0:2.0] and also crystallization time (2-6 hour) on the BMB yield (%) was investigated at 80 °C reaction temperature. It is found that, BMB precipitation synthesis with 90 % yield can be performed from 0.50 molar ration (BDH:Ba), under 80 °C, 15 minute, and 6 hours crystallization time. The structural properties of BMB powders were characterized by using XRD, FT-IR and DTA-TG instrumental analysis technique.

  5. Enhancement of bradykinin and resensitization of its B2 receptor.

    Marcic, B; Deddish, P A; Jackman, H L; Erdös, E G

    1999-03-01

    We studied the enhancement of the effects of bradykinin B2 receptor agonists by agents that react with active centers of angiotensin-converting enzyme (ACE) independent of enzymatic inactivation. The potentiation and the desensitization and resensitization of B2 receptor were assessed by measuring [3H]arachidonic acid release and [Ca2+]i mobilization in Chinese hamster ovary cells transfected to express human ACE and B2 receptor, or in endothelial cells with constitutively expressed ACE and receptor. Administration of bradykinin or its ACE-resistant analogue desensitized the receptor, but it was resensitized (arachidonic acid release or [Ca2+]i mobilization) by agents such as enalaprilat (1 micromol/L). Enalaprilat was inactive in the absence of ACE expression. La3+ (100 micromol/L) inhibited the apparent resensitization, probably by blocking the entry of extracellular calcium. Enalaprilat resensitized the receptor via ACE to release arachidonic acid by bradykinin at a lower concentration (5 nmol/L) than required to mobilize [Ca2+]i (1 micromol/L). Monoclonal antibodies inhibiting the ACE N-domain active center and polyclonal antiserum potentiated bradykinin. The snake venom peptide BPP5a and metabolites of angiotensin and bradykinin (angiotensin-[1-9], angiotensin-[1-7], bradykinin-[1-8]; 1 micromol/L) enhanced arachidonic acid release by bradykinin. Angiotensin-(1-9) and -(1-7) also resensitized the receptor. Enalaprilat potentiated the bradykinin effect in cells expressing a mutant ACE with a single N-domain active site. Agents that reacted with a single active site, on the N-domain or on the C-domain, potentiated bradykinin not by blocking its inactivation but by inducing crosstalk between ACE and the receptor. Enalaprilat enhanced signaling via ACE by Galphai in lower concentration than by Galphaq-coupled receptor.

  6. On heavy carbon doping of MgB2

    Kasinathan, Deepa; Lee, K.-W.; Pickett, W.E.

    2005-01-01

    Heavy carbon doping of MgB 2 is studied by first principles electronic structure studies of two types, an ordered supercell (Mg(B 1-x C x ) 2 , x 0.0833) and also the coherent potential approximation method that incorporates effects of B-C disorder. For the ordered model, the twofold degenerate σ-bands that are the basis of the high temperature superconductivity are split by 60 meV (i.e. 7 meV/% C) and the σ Fermi cylinders contain 0.070 holes/cell, compared to 0.11 for MgB 2 . A virtual crystal treatment tends to overestimate the rate at which σ holes are filled by substitutional carbon. The coherent potential approximation (CPA) calculations give the same rate of band filling as the supercell method. The occupied local density of states of C is almost identical to that of B in the upper 2 eV of the valence bands, but in the range -8 eV to -2 eV, C has a considerably larger density of states. The calculations indicate that the σ Fermi surface cylinders pinch off at the zone center only above the maximum C concentration x ∼ 0.10. These results indicate that Mg(B 1-x C x ) 2 as well as Mg 1-x Al x B 2 is a good system in which to study the evolution of the unusual electron-phonon coupling character and strength as the crucial σ hole states are filled

  7. B2B-verkkokaupan markkinointiviestintäsuunnitelma

    Luoma, Hanna

    2015-01-01

    Opinnäytetyön aiheena oli luoda markkinointiviestintäsuunnitelma Yritys Oy:n kehitteillä olevalle verkkokaupalle. Työn tavoitteena oli markkinointiviestintäsuunnitelman avulla selvittää miten Yritys Oy:n B2B-verkkokauppa saadaan osaksi myyntitoimia ja miten se mahdollisimman tehokkaasti tuodaan asiakkaiden tietoisuuteen. Yritys Oy on vuonna 2003 perustettu perheyritys, jonka toiminta on kiinnitystekniikan tukkumyynti alan ammattilaisille. Yritys Oy:llä on useampi toimipiste ympäri Suomea...

  8. Strategic Insights from Mystery Shopping in B2B Relationships

    Mattsson, Jan

    2012-01-01

    This paper describes how mystery shopping can be used to gain valuable strategic input in B2B service relationships. We account for a longitudinal case study framed as a natural experiment (duration 18 months) in a Swedish group of consultancy companies offering a wide selection of industrial...... guideline covering the themes of map, smoke and mirror as metaphors) has been extended to comprise a larger group of engineers and may be taken up in a company-wide way. The experiment was deemed effective in developing both a procedure for mystery shopping and a new way to train the consultants....

  9. Properties of hot pressed MgB2/Ti tapes

    Kovac, P.; Husek, I.; Melisek, T.; Fedor, J.; Cambel, V.; Morawski, A.; Kario, A.

    2009-01-01

    Hot axial and hot isostatic pressing was applied for single-core MgB 2 /Ti tapes. Differences in transport current density, n-exponents and critical current anisotropy are discussed and related to the grain connectivity influenced by pressing. The magnetic Hall probe scanning measurements allowed observing the isolated regions for axially hot pressed sample attributed to the longitudinally oriented cracks introduced by pressing. The highest current densities were measured for the tape subjected to hot isostatic pressing due to improved connectivity.

  10. Specific heat of MgB_2 after irradiation

    Wang, Yuxing; Bouquet, Frederic; Sheikin, Ilya; Toulemonde, Pierre; Revaz, Bernard; Eisterer, Michael; Weber, Harald W.; Hinderer, Joerg; Junod, Alain

    2002-01-01

    We studied the effect of disorder on the superconducting properties of polycrystalline MgB_2 by specific-heat measurements. In the pristine state, these measurements give a bulk confirmation of the presence of two superconducting gaps with 2 Delta 0 / k_B T_c = 1.3 and 3.9 with nearly equal weights. The scattering introduced by irradiation suppresses T_c and tends to average the two gaps although less than predicted by theory. We also found that by a suitable irradiation process by fast neutr...

  11. Bu-2470, a new peptide antibiotic complex. II. Structure determination of Bu-2470 A, B1, B2a and B2b.

    Sugawara, K; Yonemoto, T; Konishi, M; Matsumoto, K; Miyaki, T; Kawaguchi, H

    1983-06-01

    The structures of Bu-2470 A, B1, B2a, and B2b have been determined. Bu-2470 A is a simple octapeptide having no fatty acid moiety, while Bu-2470 B1, B2a and B2b are octapeptides that have been acylated with a beta-hydroxy C11 or C10 fatty acid. The octapeptide structure of Bu-2470 components was found identical with that of octapeptin C1, hence generic names of octapeptin C0, C2, C3 and C4 are proposed for Bu-2470 A, B1, B2a and B2b, respectively.

  12. The purification step is not crucial in EIA measurements of thromboxane B2 and 11-dehydrothromboxane B2 in human plasma.

    Sadilkova, Lenka; Paluch, Zoltan; Mottlova, Jirina; Bednar, Frantisek; Alusik, Stefan

    2012-01-01

    Thromboxane B2 (TxB2) and particularly 11-dehydrothromboxane B2 (11-dTxB2) are widely used as prognostic risk markers of platelet activation in cardiovascular diseases. The main errors in TxB2 and 11-dTxB2 determination include either low concentrations of circulating TxB2 (1 - 2 pg/mL) and 11-dTxB2 (0.9 - 4.3 pg/mL) or rather high transiency (mean TxB2 half-life is approximately 5 minutes) as well as an incorrect pre-analytical phase set up. The aim of this study was to investigate the impact of a widely used purification step on the results of enzyme immunosorbent assay (EIA)--based measurement of the two selected thromboxanes. For the purpose of this study, 20 plasma samples (10 healthy donors, 10 patients under treatment with acetylsalicylic acid) were screened for TxB2 and 11-dTxB2 concentrations using commercial competitive EIA kits (Cayman Chemicals, Tallinn, Estonia; Neogen, Lexington, KY, USA) with or without the introduction of the purification procedure. The purification step does not significantly affect the results of EIA measurements of the two of TxA2 metabolites (TxB2, 11-dTxB2) in human plasma. The levels of TxB2 and 11-dTxB2 determined in the plasma samples were not significantly changed (p < 0.05) when the purification step was omitted compared to the purified samples. This study establishes a protocol allowing for reliable and reproducible plasma TxB2 and 11-dTxB2 EIA measurement for routine basic screening of platelet function.

  13. MgB2-based superconductors for fault current limiters

    Sokolovsky, V.; Prikhna, T.; Meerovich, V.; Eisterer, M.; Goldacker, W.; Kozyrev, A.; Weber, H. W.; Shapovalov, A.; Sverdun, V.; Moshchil, V.

    2017-02-01

    A promising solution of the fault current problem in power systems is the application of fast-operating nonlinear superconducting fault current limiters (SFCLs) with the capability of rapidly increasing their impedance, and thus limiting high fault currents. We report the results of experiments with models of inductive (transformer type) SFCLs based on the ring-shaped bulk MgB2 prepared under high quasihydrostatic pressure (2 GPa) and by hot pressing technique (30 MPa). It was shown that the SFCLs meet the main requirements to fault current limiters: they possess low impedance in the nominal regime of the protected circuit and can fast increase their impedance limiting both the transient and the steady-state fault currents. The study of quenching currents of MgB2 rings (SFCL activation current) and AC losses in the rings shows that the quenching current density and critical current density determined from AC losses can be 10-20 times less than the critical current determined from the magnetization experiments.

  14. Magnesium diboride(MgB2) wires for applications

    Patel, Dipak; Kim, Jung Ho

    2016-01-01

    Field and temperature dependence of the critical current density, Jc, were measured for both un-doped and carbon doped MgB 2 /Nb/Monel wires manufactured by Hyper Tech Research, Inc. In particular, carbon incorporation into the MgB 2 structure using malic acid additive and a chemical solution method can be advantageous because of the highly uniform mixing between the carbon and boron powders. At 4.2 K and 10 T, Jc was estimated to be 25,000 - 25,300 Acm -2 for the wire sintered at 600 degrees C for 4 hours. The irreversibility field, Birr, of the malic acid doped wire was approximately 21.0 - 21.8 T, as obtained from a linear extrapolation of the J-B characteristic. Interestingly enough, the Jc of the malic acid doped sample exceeds 10 5 Acm -2 at 6 T and 4.2 K, which is comparable to that of commercial Nb-Ti wires

  15. USING UML SCENARIOS IN B2B SYSTEMS

    A. Jakimi

    2010-05-01

    Full Text Available Scenarios has become a popular technique for requirements elicitation and specification building. Since scenarios capture only partial descriptions of the system behavior, an approach for scenario composition and/or integration is needed to produce more complete specifications. The Unified Modeling Language (UML, which has become a standard notation for object-oriented modeling, provides a suitable framework for scenario acquisition using Use Case diagrams and Sequence or Collaboration diagrams. In this paper, we suggest an algorithmic and tool support for composing and integrating scenarios that are represented in form of sequence diagrams. We suggest four operators (;: sequential operator, ||: concurrent operator, ?: conditional operator and  * :iteration operator to compose a set of scenarios that describe a use case of a given system. In this paper, we suggest also to apply the scenario approach to B2B systems (Business to Business. We propose to develop B2B systems as a three activities process deriving formal specifications and code skeletons from UML scenarios. Activities of this proposed process are generally automatic and are supported by a set of developed algorithms and tools.

  16. B2FH, the Cosmic Microwave Background and Cosmology*

    Burbidge, G.

    In this talk I shall start by describing how we set about and carried out the work that led to the publication of Burbidge et al. (1957, hereafter B2FH). I then shall try and relate this work and the circumstances that surrounded it to the larger problem of the origin and formation of the universe. Here it is necessary to look back at the way that ideas developed and how, in many situations, astronomers went astray. Of course this is a personal view, though I very strongly believe that if he were still here, it is the approach that Fred Hoyle would take. I start by describing the problems originally encountered by Gamow and his associates in trying to decide where the helium was made. This leads me to a modern discussion of the origin of 2D, 3He, 4He and 7Li, originally described by B2FH as due to the x-process. While it is generally argued, following Gamow, Alpher, and Herman, that these isotopes were synthesised in a big bang I shall show that it is equally likely that these isotopes were made in active galactic nuclei, as was the cosmic microwave background (CMB), in a cyclic universe model. The key piece of observational evidence is that the amount of energy released in the conversion of hydrogen to helium in the universe is very close to the energy carried by the CMB, namely ~4.5 × 10-13 erg cm-3.

  17. Vortex lattice structures in YNi2B2C

    Yethiraj, M.; Paul, D.M.; Tomy, C.V.; Forgan, E.M.

    1997-01-01

    The authors observe a flux lattice with square symmetry in the superconductor YNi 2 B 2 C when the applied field is parallel to the c-axis of the crystal. A square lattice observed previously in the isostructural magnetic analog ErNi 2 B 2 C was attributed to the interaction between magnetic order in that system and the flux lattice. Since the Y-based compound does not order magnetically, it is clear that the structure of the flux lattice is unrelated to magnetic order. In fact, they show that the flux lines have a square cross-section when the applied field is parallel to the c-axis of the crystal, since the measured penetration depth along the 100 crystal direction is larger than the penetration depth along the 110 by approximately 60%. This is the likely reason for the square symmetry of the lattice. Although they find considerable disorder in the arrangement of the flux lines at 2.5T, no melting of the vortex lattice was observed

  18. Nuclear reactors

    Barre, Bertrand

    2015-10-01

    After some remarks on the nuclear fuel, on the chain reaction control, on fuel loading and unloading, this article proposes descriptions of the design, principles and operations of different types of nuclear reactors as well as comments on their presence and use in different countries: pressurized water reactors (design of the primary and secondary circuits, volume and chemistry control, backup injection circuits), boiling water reactors, heavy water reactors, graphite and boiling water reactors, graphite-gas reactors, fast breeder reactors, and fourth generation reactors (definition, fast breeding). For these last ones, six concepts are presented: sodium-cooled fast reactor, lead-cooled fast reactor, gas-cooled fast reactor, high temperature gas-cooled reactor, supercritical water-cooled reactor, and molten salt reactor

  19. Phase and Microstructural Correlation of Spark Plasma Sintered HfB2-ZrB2 Based Ultra-High Temperature Ceramic Composites

    Ambreen Nisar

    2017-07-01

    Full Text Available The refractory diborides (HfB2 and ZrB2 are considered as promising ultra-high temperature ceramic (UHTCs where low damage tolerance limits their application for the thermal protection system in re-entry vehicles. In this regard, SiC and CNT have been synergistically added as the sintering aids and toughening agents in the spark plasma sintered (SPS HfB2-ZrB2 system. Herein, a novel equimolar composition of HfB2 and ZrB2 has shown to form a solid-solution which then allows compositional tailoring of mechanical properties (such as hardness, elastic modulus, and fracture toughness. The hardness of the processed composite is higher than the individual phase hardness up to 1.5 times, insinuating the synergy of SiC and CNT reinforcement in HfB2-ZrB2 composites. The enhanced fracture toughness of CNT reinforced composite (up to a 196% increment surpassing that of the parent materials (ZrB2/HfB2-SiC is attributed to the synergy of solid solution formation and enhanced densification (~99.5%. In addition, the reduction in the analytically quantified interfacial residual tensile stress with SiC and CNT reinforcements contribute to the enhancement in the fracture toughness of HfB2-ZrB2-SiC-CNT composites, mandatory for aerospace applications.

  20. Matchmaking Framework for B2B E-Marketplaces

    Fekete ZOLTAN ALPAR

    2010-01-01

    Full Text Available In the recent years trading on the Internet become more popular. Online businesses gradually replace more and more from the conventional business. Much commercial information is exchanged on the internet, especially using the e-marketplaces. The demand and supply matching process becomes complex and difficult on last twenty years since the e-marketplaces play an important role in business management. Companies can achieve significant cost reduction by using e-marketplaces in their trade activities and by using matchmaking systems on finding the corresponding supply for their demand and vice versa. In the literature were proposed many approaches for matchmaking. In this paper we present a conceptual framework of matchmaking in B2B e-marketplaces environment.

  1. Relationship Quality as Predictor of B2B Customer Loyalty

    Shaimaa S. B. Ahmed Doma

    2013-02-01

    Full Text Available Relationship marketing has become extremely important recently due to the fierce competition in today's marketplace. Companies are required to build long-term profitable relationship with customers and to achieve customer loyalty. Also, switching behaviors frequently occur among most of targeted customers. Fewer studies, however, discuss the effects of relationship quality efforts on customer loyalty. Therefore, this study is aimed to investigate the impact of relationship quality on customer loyalty in B2B context in the Egyptian shipping services sector. Building on prior research, we propose relationship quality as a higher construct comprising trust, commitment and satisfaction. An analytical model is developed as a guideline to test the relationships between relationship quality dimensions and customer loyalty.

  2. Model of the Sgr B2 radio source

    Gosachinskij, I.V.; Khersonskij, V.K.

    1981-01-01

    The dynamical model of the gas cloud around the radio source Sagittarius B2 is suggested. This model describes the kinematic features of the gas in this source: contraction of the core and rotation of the envelope. The stability of the cloud at the initial stage is supported by the turbulent motion of the gas, turbulence energy dissipates due to magnetic viscosity. This process is occurring more rapidly in the dense core and the core begins to collapse but the envelope remains stable. The parameters of the primary cloud and some parameters (mass, density and size) of the collapse are calculated. The conditions in the core at the moment of its fragmentation into masses of stellar order are established [ru

  3. Widespread Occurrence of the Mycotoxin Fumonisin B-2 in Wine

    Mogensen, Jesper Mølgaard; Larsen, Thomas Ostenfeld; Nielsen, Kristian Fog

    2010-01-01

    Fumonisins are important mycotoxins because they are suspected to cause human and animal toxicoses by the consumption of contaminated corn-based food and feeds. However, with the discovery of fumonisin production in grapes by Aspergillus niger, wine may also be a fumonisin-containing commodity....... In the present study, we have developed a simple and quantitative cation-exchange-based purification method for the subsequent isotope dilution liquid chromatography tandem mass spectrometry (LC-MS/MS) determination of fumonisins in wine. A comparative study of seven different solid-phase extraction (SPE......) columns showed that polymeric mixed-mode reversed-phase (RP) cation-exchange columns were superior to classic silica-based cation and mixed-mode cation-exchange columns. A total of 77 wine samples from 13 countries were subsequently tested, and surprisingly, 18 (23%) were found to contain fumonisin B-2...

  4. Directional scanning tunneling spectroscopy in MgB2

    Iavarone, M.; Karapetrov, G.; Koshelev, A.E.; Kwok, W.K.; Crabtree, G.W.; Hinks, D.G.; Cook, R.; Kang, W.N.; Choi, E.M.; Kim, H.J.; Lee, S.I.

    2003-01-01

    The superconductivity in MgB 2 has a two-band character with the dominating band having a 2D character and the second band being isotropic in the three dimensions. We use tunneling microscopy and spectroscopy to reveal the two distinct energy gaps at Δ 1 =2.3 meV and Δ 2 =7.1 meV. Different spectral weights of the partial superconducting density of states are a reflection of different tunneling directions in this multi-band system. The results are consistent with the existence of two-band superconductivity in the presence of strong interband superconducting pair interaction and quasiparticle scattering. The temperature evolution of the tunneling spectra shows both gaps vanishing at the bulk T c

  5. Diatomic substitutionals in superconducting Nb(1-x)B2

    Farrell, H.H.; LaViolette, Randall A.; Lillo, T.M.

    2006-01-01

    Using first-principles, density functional theory calculations, we have shown that the increase in superconducting critical temperature to above 9 K experimentally observed for B-rich, off-stoichiometry NbB 2 material is associated with the formation of B-dimers on Nb sites rather than with the formation of Nb vacancies, as previously proposed. Our calculations show that certain of these B-dimer configurations have lower binding energies than do the vacancy structures. This result is pressure independent in the range between 0 and 10 GPa, and above. Further, the dimer-containing materials have a higher electronic density of states at the Fermi level than do the vacancy structures. Finally, the presence of B-dimers results in the splitting off of phonon normal modes. These last two factors are relevant to the improved superconducting properties

  6. Specific heat of MgB2 after irradiation

    Wang Yuxing; Bouquet, Frederic; Sheikin, Ilya; Toulemonde, Pierre; Revaz, Bernard; Eisterer, Michael; Weber, Harald W; Hinderer, Joerg; Junod, Alain

    2003-01-01

    We studied the effect of disorder on the superconducting properties of polycrystalline MgB 2 by specific-heat measurements. In the pristine state, these measurements give a bulk confirmation of the presence of two superconducting gaps with 2Δ 0 /k B T c =1.3 and 3.9 with nearly equal weights. The scattering introduced by irradiation suppresses T c and tends to average the two gaps although less than predicted by theory. We also found that by a suitable irradiation process by fast neutrons, a substantial bulk increase of dH c2 /dT at T c can be obtained without sacrificing more than a few degrees in T c . The upper critical field of the sample after irradiation exceeds 28 T at T→0

  7. Podwójna negacja w B 2 poematu Parmenidesa

    Kazimierz MRÓWKA

    2012-12-01

    Full Text Available In our article we focus on an analysis of the structure of double negation in the poem of Parmenides,paying attention to the fragment B 2. The starting point for the analysis is the classificationof varieties of negation contained in Diogenes Laertius (VII.69-70: negation, denial,privation and double negation. We provide an example of double negation as given by Diogenes: “Not (is not a day ↔ it is a day”. In terms of the poetic expression the law of double negationserves to strengthen the goddess’ speech. However, in the context of Parmenides’ ontology, thelaw of double negation serves as an affirmation of “is”. Our goal is to give a detailed analysis ofthe structure of double negation. In the next step we introduce Euclid’s proofs by comparison.We show that all four forms of negation indicated by Diogenes occur in the Elements and thereis a richer set of the linguistic forms used as an expression of negation, including that of doublenegation. Finally, we show that Parmenides applies consciously the law of double negation,and the poem is the first philosophical text confirming the use of this law. In short, doublenegation can be summarized as follows: for the Stoics, in Diogenes Laertius (VII.69-70: “not(is not a day ↔ is a day”; for Euclid: “not (is not-equal ↔ is equal” (Elements, I.6. “is notlike that (.... is not around ... ↔ is around” (Elements VI.26; and in Parmenides: “is ↔ not(is not to be” (B 2, v. 3.

  8. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    An, Jing; Song, Jinpeng; Liang, Guoxing; Gao, Jiaojiao; Xie, Juncai; Cao, Lei; Wang, Shiying; Lv, Ming

    2017-01-01

    The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure. PMID:28772821

  9. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Jing An

    2017-04-01

    Full Text Available The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure.

  10. Nanostructure characterization of Ni and B layers as artificial pinning centers in multilayered MgB2/Ni and MgB2/B superconducting thin films

    Sosiati, H.; Hata, S.; Doi, T.; Matsumoto, A.; Kitaguchi, H.; Nakashima, H.

    2013-01-01

    Highlights: ► Nanostructure characterization of Ni and B layers as artificial pinning centers (APCs). ► Relationship between nanostructure and J c property. ► Enhanced J c in parallel field by parallel APCs within the MgB 2 film. -- Abstract: Research on the MgB 2 /Ni and MgB 2 /B multilayer films fabricated by an electron beam (EB) evaporation technique have been extensively carried out. The critical current density, J c of MgB 2 /Ni and MgB 2 /B multilayer films in parallel fields has been suggested to be higher than that of monolayer MgB 2 film due to introducing the artificial pinning centers of nano-sized Ni and B layers. Nanostructure characterization of the artificial pinning centers in the multilayer films were examined by transmission electron microscopy (TEM) and scanning TEM (STEM-energy dispersive X-ray spectroscopy (STEM-EDS))–EDS to understand the mechanism of flux pinning. The growth of columnar MgB 2 grains along the film-thickness direction was recognized in the MgB 2 /Ni multilayer film, but not in the MgB 2 /B multilayer film. Nano-sized Ni layers were present as crystalline epitaxial layers which is interpreted that Ni atoms might be incorporated into the MgB 2 lattice to form (Mg,Ni)B 2 phase. On the other hand, nano-sized B layers were amorphous layers. Crystalline (Mg,Ni)B 2 layers worked more effectively than amorphous B-layers, providing higher flux-pinning force that resulted in higher J c of the MgB 2 /Ni multilayer film than the MgB 2 /B multilayer film

  11. Getting started with Oracle SOA B2B Integration a hands-on tutorial

    Bhatia, Krishnaprem; Perlovsky, Alan

    2013-01-01

    This hands on tutorial gives you the best possible start you could hope for with Oracle B2B. Learn using real life scenarios and examples to give you a solid footing of B2B.This book is for B2B architects, consultants and developers who would like to design and develop B2B integrations using Oracle B2B. This book assumes no prior knowledge of Oracle B2B and explains all concepts from scratch using illustrations, real world examples and step-by-step instructions. The book covers enough depth and details to be useful for both beginner and advanced B2B users.

  12. H Reactor

    Federal Laboratory Consortium — The H Reactor was the first reactor to be built at Hanford after World War II.It became operational in October of 1949, and represented the fourth nuclear reactor on...

  13. High temperature microhardness of ZrB2 single crystals

    Yi Xuan; Chen Chunhua; Otani, Shigeki

    2002-01-01

    Vickers microhardness of (0001), (101-bar 0) and (112-bar 0) planes of ZrB 2 single crystal prepared by the floating zone method has been investigated at various temperatures and loading times. As the temperature increases from 25 deg. C to 1000 deg. C, hardness drops from ∼20.9 GN m -2 of all planes to ∼7.85 GN m -2 for (0001) plane and ∼4.91 GN m -2 for (101-bar 0) and (112-bar 0) planes. The hardness of (101-bar 0) and (112-bar 0) planes exhibits almost same tendency and is always lower than that of (0001) plane by about 35%. The thermal softening coefficients of all three planes strongly depends on the temperature range with clear inflections at 400 deg. C and 700 deg. C. The loading time dependence of hardness is used to calculate the activation energy for creep. In addition, a relationship was found that shows the variation of hardness with temperature to be proportional to the variation with the loading time in a specific temperature range. (rapid communication)

  14. Lightweight MgB2 superconducting 10 MW wind generator

    Marino, I.; Pujana, A.; Sarmiento, G.; Sanz, S.; Merino, J. M.; Tropeano, M.; Sun, J.; Canosa, T.

    2016-02-01

    The offshore wind market demands a higher power rate and more reliable turbines in order to optimize capital and operational costs. The state-of-the-art shows that both geared and direct-drive conventional generators are difficult to scale up to 10 MW and beyond due to their huge size and weight. Superconducting direct-drive wind generators are considered a promising solution to achieve lighter weight machines. This work presents an innovative 10 MW 8.1 rpm direct-drive partial superconducting generator using MgB2 wire for the field coils. It has a warm iron rotor configuration with the superconducting coils working at 20 K while the rotor core and the armature are at ambient temperature. A cooling system based on cryocoolers installed in the rotor extracts the heat from the superconducting coils by conduction. The generator's main parameters are compared against a permanent magnet reference machine, showing a significant weight and size reduction. The 10 MW superconducting generator concept will be experimentally validated with a small-scale magnetic machine, which has innovative components such as superconducting coils, modular cryostats and cooling systems, and will have similar size and characteristics as the 10 MW generator.

  15. Lightweight MgB2 superconducting 10 MW wind generator

    Marino, I; Pujana, A; Sarmiento, G; Sanz, S; Merino, J M; Tropeano, M; Sun, J; Canosa, T

    2016-01-01

    The offshore wind market demands a higher power rate and more reliable turbines in order to optimize capital and operational costs. The state-of-the-art shows that both geared and direct-drive conventional generators are difficult to scale up to 10 MW and beyond due to their huge size and weight. Superconducting direct-drive wind generators are considered a promising solution to achieve lighter weight machines. This work presents an innovative 10 MW 8.1 rpm direct-drive partial superconducting generator using MgB 2 wire for the field coils. It has a warm iron rotor configuration with the superconducting coils working at 20 K while the rotor core and the armature are at ambient temperature. A cooling system based on cryocoolers installed in the rotor extracts the heat from the superconducting coils by conduction. The generator’s main parameters are compared against a permanent magnet reference machine, showing a significant weight and size reduction. The 10 MW superconducting generator concept will be experimentally validated with a small-scale magnetic machine, which has innovative components such as superconducting coils, modular cryostats and cooling systems, and will have similar size and characteristics as the 10 MW generator. (paper)

  16. Bond deformation paths and electronic instabilities of ultraincompressible transition metal diborides: Case study of OsB2 and IrB2

    Zhang, R. F.; Legut, D.; Wen, X. D.; Veprek, S.; Rajan, K.; Lookman, T.; Mao, H. K.; Zhao, Y. S.

    2014-09-01

    The energetically most stable orthorhombic structure of OsB2 and IrB2 is dynamically stable for OsB2 but unstable for IrB2. Both diborides have substantially lower shear strength in their easy slip systems than their metal counterparts. This is attributed to an easy sliding facilitated by out-of-plane weakening of metallic Os-Os bonds in OsB2 and by an in-plane bond splitting instability in IrB2. A much higher shear resistance of Os-B and B-B bonds than Os-Os ones is found, suggesting that the strengthened Os-B and B-B bonds are responsible for hardness enhancement in OsB2. In contrast, an in-plane electronic instability in IrB2 limits its strength. The electronic structure of deformed diborides suggests that the electronic instabilities of 5d orbitals are their origin of different bond deformation paths. Neither IrB2 nor OsB2 can be intrinsically superhard.

  17. The conserved nhaAR operon is drastically divergent between B2 and non-B2 Escherichia coli and is involved in extra-intestinal virulence.

    Lescat, Mathilde; Reibel, Florence; Pintard, Coralie; Dion, Sara; Glodt, Jérémy; Gateau, Cecile; Launay, Adrien; Ledda, Alice; Cruveiller, Stephane; Cruvellier, Stephane; Tourret, Jérôme; Tenaillon, Olivier

    2014-01-01

    The Escherichia coli species is divided in phylogenetic groups that differ in their virulence and commensal distribution. Strains belonging to the B2 group are involved in extra-intestinal pathologies but also appear to be more prevalent as commensals among human occidental populations. To investigate the genetic specificities of B2 sub-group, we used 128 sequenced genomes and identified genes of the core genome that showed marked difference between B2 and non-B2 genomes. We focused on the gene and its surrounding region with the strongest divergence between B2 and non-B2, the antiporter gene nhaA. This gene is part of the nhaAR operon, which is in the core genome but flanked by mobile regions, and is involved in growth at high pH and high sodium concentrations. Consistently, we found that a panel of non-B2 strains grew faster than B2 at high pH and high sodium concentrations. However, we could not identify differences in expression of the nhaAR operon using fluorescence reporter plasmids. Furthermore, the operon deletion had no differential impact between B2 and non-B2 strains, and did not result in a fitness modification in a murine model of gut colonization. Nevertheless, sequence analysis and experiments in a murine model of septicemia revealed that recombination in nhaA among B2 strains was observed in strains with low virulence. Finally, nhaA and nhaAR operon deletions drastically decreased virulence in one B2 strain. This effect of nhaAR deletion appeared to be stronger than deletion of all pathogenicity islands. Thus, a population genetic approach allowed us to identify an operon in the core genome without strong effect in commensalism but with an important role in extra-intestinal virulence, a landmark of the B2 strains.

  18. Structural, mechanical, and electronic properties of TaB2, TaB, IrB2, and IrB: First-principle calculations

    Zhao Wenjie; Wang Yuanxu

    2009-01-01

    First-principle calculations were performed to investigate the structural, elastic, and electronic properties of TaB 2 , TaB, IrB 2 , and IrB. The calculated equilibrium structural parameters, shear modulus, and Young's modulus of TaB 2 are well consistent with the available experimental data, and TaB 2 with P6/mmm space group has stronger directional bonding between ions than WB 2 , OsB 2 , IrN 2 , and PtN 2 . For TaB 2 , the hexagonal P6/mmm structure is more stable than the orthorhombic Pmmn one, while for IrB 2 the orthorhombic Pmmn structure is the most stable one. The high shear modulus of P6/mmm phase TaB 2 is mainly due to the strong covalent π-bonding of B-hexagon in the (0001) plane. Such a B-hexagon network can strongly resist against an applied [112-bar0] (0001) shear deformation. Correlation between the hardness and the elastic constants of TaB 2 was discussed. The band structure shows that P6/mmm phase TaB 2 and Pmmn phase IrB 2 are both metallic. The calculations show that both TaB and IrB are elastically stable with the hexagonal P6 3 /mmc structure. - Elastic constant c 44 of TaB 2 is calculated to be 235 GPa. This value is exceptionally high, exceeding those of WB 2 , OsB 2 , WB 4 , OsN 2 , IrN 2 , and PtN 2 .

  19. Microstructural characterization of LaB6-ZrB2 eutectic composites

    Wang Shengchang; Wei, W.J.; Zhang Litong

    2003-01-01

    Detail microstructure of LaB 6 -ZrB 2 composites has been characterized by TEM and HRTEM. The directionally solidified ZrB 2 fibers in LaB 6 matrix near LaB 6 -ZrB 2 eutectics present at least three growing relationship systems. In addition to previous report of [001]LaB 6 / [0001]ZrB 2 relationship, [0 anti 11]LaB 6 / [0001]ZrB 2 and [1 anti 20]LaB 6 / [0001]ZrB 2 . were identified. Different with [001]LaB 6 / [0001]ZrB 2 system, the interfaces of [0 anti 11]LaB 6 / [0001]ZrB 2 and [1 anti 20]LaB 6 / [0001]ZrB 2 . show non-coherent and clean interfaces. There is neither glassy phase nor reaction products found at the interfaces (orig.)

  20. The CVD ZrB2 as a selective solar absorber

    Randich, E.; Allred, D. D.

    Coatings of ZrB2 and TiB2 for photothermal solar absorber applications were prepared using chemical vapor deposition (CVD) techniques. Oxidation tests suggest a maximum temperature limit for air exposure of 600 K for TiB2 and 800 K for Z4B2. Both materials exhibit innate spectral selectivity with emittance at 375 K ranging from 0.06 to 0.09 and solar absorptance for ZrB2 ranging from 0.67 to 0.77 and solar absorptance for TiB2 ranging from 0.46 to 0.58. ZrB2 has better solar selectivity and more desirable oxidation behavior than TiB2. A 0.071 micrometer antireflection coating of Si3N4 deposited on the ZrB2 coating leads to an increase in absorptance from 0.77 to 0.93, while the emittance remains unchanged.

  1. Beyond the exchange--the future of B2B.

    Wise, R; Morrison, D

    2000-01-01

    Using the Internet to facilitate business-to-business commerce promises many benefits, such as dramatic cost reductions and greater access to buyers and sellers. Yet little is known about how B2B e-commerce will evolve. The authors argue that changes in the financial services industry over the past two decades provide important clues. Exchanges, they say, are not the primary source of value in information-intensive markets; value tends to accumulate among a diverse group of specialists that focus on such tasks as packaging, standard setting, arbitrage, and information management. Because scale and liquidity are vitally important to efficient trading, today's exchanges will consolidate into a relatively small set of mega-exchanges. Originators will handle the origination and aggregation of complex transactions before sending them on to mega-exchanges for execution. E-speculators, seeking to capitalize on an abundance of market information, will tend to concentrate where relatively standardized products can be transferred easily among a large group of buyers. In many markets, a handful of independent solution providers with well-known brand names and solid reputations will thrive alongside mega-exchanges. Sell-side asset exchanges will create the networks and provide the tools to allow suppliers to trade orders among themselves, sometimes after initial transactions with customers are made on the mega-exchanges. For many companies, traditional skills in such areas as product development, manufacturing, and marketing may become relatively less important, while the ability to understand and capitalize on market dynamics may become considerably more important.

  2. Thermal Vacuum Integrated System Test at B-2

    Kudlac, Maureen T.; Weaver, Harold F.; Cmar, Mark D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Space Propulsion Research Facility, commonly referred to as B-2, is NASA s third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility during pump down of the vacuum chamber, operation of the liquid nitrogen heat sink (or cold wall) and the infrared lamp array. A vacuum level of 1.3x10(exp -4)Pa (1x10(exp -6)torr) was achieved. The heat sink provided a uniform temperature environment of approximately 77 K (140deg R) along the entire inner surface of the vacuum chamber. The recently rebuilt and modernized infrared lamp array produced a nominal heat flux of 1.4 kW/sq m at a chamber diameter of 6.7 m (22 ft) and along 11 m (36 ft) of the chamber s cylindrical vertical interior. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface. The data acquired matched pretest predictions and demonstrated system functionality.

  3. Microwave surface impedance of MgB2 thin film

    Jin, B B; Klein, N; Kang, W N; Kim, Hyeong-Jin; Choi, Eun-Mi; Lee, Sung-I K; Dahm, T; Maki, K

    2003-01-01

    The microwave surface impedance Z s = R s + jωμ 0 λ was measured with dielectric resonator techniques for two c-axis-oriented MgB 2 thin films. The temperature dependence of the penetration depth λ measured with a sapphire resonator at 17.93 GHz can be well fitted from 5 K close to T c by the standard BCS integral expression assuming the reduced energy gap Δ(0)/kT c to be as low as 1.13 and 1.03 for the two samples. From these fits the penetration depth at zero temperatures was determined to be 102 nm and 107 nm, respectively. The results clearly indicate the s-wave nature of the order parameter. The temperature dependence of surface resistance R s , measured with a rutile dielectric resonator, shows an exponential behaviour below about T c /2 with a reduced energy gap being consistent with the one determined from the λ data. The R s value at 4.2 K was found to be as low as 19 μΩ at 7.2 GHz, which is comparable with that of a high-quality high-temperature thin film of YBa 2 Cu 3 O 7 . A higher-order mode at 17.9 GHz was employed to determine the frequency f dependence of R s ∝ f n(T) . Our results revealed a decrease of n with increasing temperature ranging from n = 2 below 8 K to n 1 from 13 to 34 K

  4. Experiences and Future Expectations towards Online Courses--An Empirical Study of the B2C-and B2B-Segments

    Krämer, Andreas; Böhrs, Sandra

    2016-01-01

    This article explores the future potential for the development of online courses. The findings are based on an empirical study with 3 sample groups: (1) B2C segment in Germany, (2) B2C segment in the United States, and (3) B2B segment (international). In the first step the status quo of the use of e-learning in general and online courses in…

  5. Study on Logistics Distribution Centers for B2C Online Shopping%B2C网购物流配送中心研究

    侯凌燕; 尹军琪

    2011-01-01

    分析了我国B2C网购物流配送的现状,对其特点和难点作了分析,并提出了相应的B2C网购物流配送中心设计解决方案.%The paper analyzes the current status of the logistics and distribution operations for B2C online shopping in China, analyzes its characteristics and existing issues, and puts forth solutions for the design of logistics and distribution centers for B2C online shopping.

  6. Clinical relevance of ErbB-2/HER2 nuclear expression in breast cancer

    Schillaci, Roxana; Charreau, Eduardo H; Maronna, Esteban; Roa, Juan C; Elizalde, Patricia V; Guzmán, Pablo; Cayrol, Florencia; Beguelin, Wendy; Díaz Flaqué, María C; Proietti, Cecilia J; Pineda, Viviana; Palazzi, Jorge; Frahm, Isabel

    2012-01-01

    The biological relevance of nuclear ErbB-2/HER2 (NuclErbB-2) presence in breast tumors remains unexplored. In this study we assessed the clinical significance of ErbB-2 nuclear localization in primary invasive breast cancer. The reporting recommendations for tumor marker prognostic studies (REMARK) guidelines were used as reference. Tissue microarrays from a cohort of 273 primary invasive breast carcinomas from women living in Chile, a Latin American country, were examined for membrane (MembErbB-2) and NuclErbB-2 expression by an immunofluorescence (IF) protocol we developed. ErbB-2 expression was also evaluated by immunohistochemistry (IHC) with a series of antibodies. Correlation between NuclErbB-2 and MembErbB-2, and between NuclErbB-2 and clinicopathological characteristics of tumors was studied. The prognostic value of NuclErbB-2 in overall survival (OS) was evaluated using Kaplan-Meier method, and Cox model was used to explore NuclErbB-2 as independent prognostic factor for OS. The IF protocol we developed showed significantly higher sensitivity for detection of NuclErbB-2 than IHC procedures, while its specificity and sensitivity to detect MembErbB-2 were comparable to those of IHC procedures. We found 33.6% NuclErbB-2 positivity, 14.2% MembErbB-2 overexpression by IF, and 13.0% MembErbB-2 prevalence by IHC in our cohort. We identified NuclErbB-2 positivity as a significant independent predictor of worse OS in patients with MembErbB-2 overexpression. NuclErbB-2 was also a biomarker of lower OS in tumors that overexpress MembErbB-2 and lack steroid hormone receptors. We revealed a novel role for NuclErbB-2 as an independent prognostic factor of poor clinical outcome in MembErbB-2-positive breast tumors. Our work indicates that patients presenting NuclErbB-2 may need new therapeutic strategies involving specific blockage of ErbB-2 nuclear migration

  7. Clinical relevance of ErbB-2/HER2 nuclear expression in breast cancer

    Schillaci Roxana

    2012-02-01

    Full Text Available Abstract Background The biological relevance of nuclear ErbB-2/HER2 (NuclErbB-2 presence in breast tumors remains unexplored. In this study we assessed the clinical significance of ErbB-2 nuclear localization in primary invasive breast cancer. The reporting recommendations for tumor marker prognostic studies (REMARK guidelines were used as reference. Methods Tissue microarrays from a cohort of 273 primary invasive breast carcinomas from women living in Chile, a Latin American country, were examined for membrane (MembErbB-2 and NuclErbB-2 expression by an immunofluorescence (IF protocol we developed. ErbB-2 expression was also evaluated by immunohistochemistry (IHC with a series of antibodies. Correlation between NuclErbB-2 and MembErbB-2, and between NuclErbB-2 and clinicopathological characteristics of tumors was studied. The prognostic value of NuclErbB-2 in overall survival (OS was evaluated using Kaplan-Meier method, and Cox model was used to explore NuclErbB-2 as independent prognostic factor for OS. Results The IF protocol we developed showed significantly higher sensitivity for detection of NuclErbB-2 than IHC procedures, while its specificity and sensitivity to detect MembErbB-2 were comparable to those of IHC procedures. We found 33.6% NuclErbB-2 positivity, 14.2% MembErbB-2 overexpression by IF, and 13.0% MembErbB-2 prevalence by IHC in our cohort. We identified NuclErbB-2 positivity as a significant independent predictor of worse OS in patients with MembErbB-2 overexpression. NuclErbB-2 was also a biomarker of lower OS in tumors that overexpress MembErbB-2 and lack steroid hormone receptors. Conclusions We revealed a novel role for NuclErbB-2 as an independent prognostic factor of poor clinical outcome in MembErbB-2-positive breast tumors. Our work indicates that patients presenting NuclErbB-2 may need new therapeutic strategies involving specific blockage of ErbB-2 nuclear migration.

  8. Alloy Design Data Generated for B2-Ordered Compounds

    Noebe, Ronald D.; Bozzolo, Guillermo; Abel, Phillip B.

    2003-01-01

    Developing alloys based on ordered compounds is significantly more complicated than developing designs based on disordered materials. In ordered compounds, the major constituent elements reside on particular sublattices. Therefore, the addition of a ternary element to a binary-ordered compound is complicated by the manner in which the ternary addition is made (at the expense of which binary component). When ternary additions are substituted for the wrong constituent, the physical and mechanical properties usually degrade. In some cases the resulting degradation in properties can be quite severe. For example, adding alloying additions to NiAl in the wrong combination (i.e., alloying additions that prefer the Al sublattice but are added at the expense of Ni) will severely embrittle the alloy to the point that it can literally fall apart during processing on cooling from the molten state. Consequently, alloying additions that strongly prefer one sublattice over another should always be added at the expense of that component during alloy development. Elements that have a very weak preference for a sublattice can usually be safely added at the expense of either element and will accommodate any deviation from stoichiometry by filling in for the deficient component. Unfortunately, this type of information is not known beforehand for most ordered systems. Therefore, a computational survey study, using a recently developed quantum approximate method, was undertaken at the NASA Glenn Research Center to determine the preferred site occupancy of ternary alloying additions to 12 different B2-ordered compounds including NiAl, FeAl, CoAl, CoFe, CoHf, CoTi, FeTi, RuAl, RuSi, RuHf, RuTi, and RuZr. Some of these compounds are potential high temperature structural alloys; others are used in thin-film magnetic and other electronic applications. The results are summarized. The italicized elements represent the previous sum total alloying information known and verify the computational

  9. INPRO phase 1B (2nd part) joint study

    Lee, Yong Bum; Kim, Young In; Hahn, Do Hee (and others)

    2006-08-15

    In this project, the Korean innovative nuclear energy system(INS) concept was assessed to be contributory to IAEA's INPRO Joint Study on CNFC-FR. The Korean INS concept was defined as an integrated system consisting of a sodium-cooled, metal fueled fast reactor KALIMER and a PWR(including CANDU)-KALIMER coupled closed nuclear fuel cycle for the Joint Study. From the results of the national scenario study performed based o the Korean INS concept, it has veen confirmed that the deployment of KALIMER from 2030 until 2100 could reduce the amount of domestic spent fuel from PWRs and CANDUs with no further increase in PWR spent fuel thereafter. And the amount of minor actinides disposed as high level would be decreased to zero with complete replacement of PWRs with KALIMERs. Based on the results of the national scenario study, a preliminary assessment of the Korean INS concept has been performed using the INPRO methodology and user's manuals. During the INS assessment, items requiring either improvement or complement have been detected in order to dedicate to INPRO's effort to improve the methodology. The INPRO methodology generally lack a consistency in a level of depth and quantity of evaluation criteria and parameters for six areas within the INPRO framework. It needs to complement application methods and guidances applicable to various technology levels as well as illustrations of assessment tools. In addition, it needs to develop quantification and aggregation of evaluated results, application of weighting factor methods, and a synthetic manual for integrated assessment procedure and methodology.

  10. INPRO phase 1B (2nd part) joint study

    Lee, Yong Bum; Kim, Young In; Hahn, Do Hee

    2006-08-01

    In this project, the Korean innovative nuclear energy system(INS) concept was assessed to be contributory to IAEA's INPRO Joint Study on CNFC-FR. The Korean INS concept was defined as an integrated system consisting of a sodium-cooled, metal fueled fast reactor KALIMER and a PWR(including CANDU)-KALIMER coupled closed nuclear fuel cycle for the Joint Study. From the results of the national scenario study performed based o the Korean INS concept, it has veen confirmed that the deployment of KALIMER from 2030 until 2100 could reduce the amount of domestic spent fuel from PWRs and CANDUs with no further increase in PWR spent fuel thereafter. And the amount of minor actinides disposed as high level would be decreased to zero with complete replacement of PWRs with KALIMERs. Based on the results of the national scenario study, a preliminary assessment of the Korean INS concept has been performed using the INPRO methodology and user's manuals. During the INS assessment, items requiring either improvement or complement have been detected in order to dedicate to INPRO's effort to improve the methodology. The INPRO methodology generally lack a consistency in a level of depth and quantity of evaluation criteria and parameters for six areas within the INPRO framework. It needs to complement application methods and guidances applicable to various technology levels as well as illustrations of assessment tools. In addition, it needs to develop quantification and aggregation of evaluated results, application of weighting factor methods, and a synthetic manual for integrated assessment procedure and methodology

  11. Tumor Suppressor Activity of the EphB2 Receptor in Prostate Cancer

    Pasquale, Elena B

    2007-01-01

    Mutations have been recently identified in the EphB2 receptor gene in prostate cancer suggesting that EphB2, a member of the large Eph receptor tyrosine kinase family, is a tumor suppressor in prostate cancer...

  12. Tumor Suppressor Activity of the EphB2 Receptor in Prostate Cancer

    Pasquale, Elena B

    2006-01-01

    Mutations have been recently identified in the EphB2 receptor gene in prostate cancer suggesting that EphB2, a member of the large Eph receptor tyrosine kinase family, is a tumor suppressor in prostate cancer...

  13. Li2b2-Façade: Simulation of i2b2 Data Warehouse Server and Client for Interaction with Other Systems.

    Majeed, Raphael W; Xu, Tingyan; Stöhr, Mark R; Röhrig, Rainer

    2017-01-01

    Since its release in 2004, the i2b2 data warehouse software has become a valuable tool for clinical researchers. Physicians can use its browser-based query frontend intuitively without additional training or reading through documentation. While the i2b2 software describes it's API as "REST", it is neither stateless nor does it follow the common guidelines for RESTful APIs. Thus, interfacing other software with i2b2's custom RPC-style XML-API is a very cumbersome process. To overcome these issues, we developed a lightweight software abstraction layer "lightweight i2b2 façade" (li2b2-façade).

  14. 17 CFR 240.13b2-1 - Falsification of accounting records.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Falsification of accounting records. 240.13b2-1 Section 240.13b2-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... Required Reports § 240.13b2-1 Falsification of accounting records. No person shall directly or indirectly...

  15. 26 CFR 1.669(b)-2 - Manner of exercising election.

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Manner of exercising election. 1.669(b)-2 Section 1.669(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... Years Beginning Before January 1, 1969 § 1.669(b)-2 Manner of exercising election. (a) By whom election...

  16. Managing Innovation Through Social Media in B2B SME-Context

    Lutz, Salla; Madsen, Svend Ole; Brink, Tove

    2015-01-01

    This paper shed light on how social media application can enhance innovation management in SME B2B context. Our study employs a qualitative case study approach with four B2B SMEs for in-depth research in the period from October 2013 to October 2014. The B2B SME managers aim for open business mode...

  17. Lectin receptor kinase LecRK-b2 localizes to plasma membrane and ...

    -b2, has been characterized. Confocal microscopy images showed that the LecRK-b2-GFP fusion protein is localized to plasma membrane. The results of yeast 2 hybrid showed that lectin domain of LecRK-b2 had selfinteraction, while the ...

  18. Nd: YAG laser treatment of aluminium-TiB2 coated: optimization of corrosion properties

    Popoola, PAI

    2011-06-01

    Full Text Available . Eutectics of TiB2/Al and TiB2/Ti were observed. The results of the tests indicate that TiB2 reinforcement does not give significant increase in microhardness of aluminium. The corrosion resistance of a single laser trackline MMC in a 3.65 % NaCl solution...

  19. 17 CFR 240.15b2-2 - Inspection of newly registered brokers and dealers.

    2010-04-01

    ... brokers and dealers. 240.15b2-2 Section 240.15b2-2 Commodity and Securities Exchanges SECURITIES AND... Regulations Under the Securities Exchange Act of 1934 Registration of Brokers and Dealers § 240.15b2-2 Inspection of newly registered brokers and dealers. (a) Definition. For the purpose of this section the term...

  20. Reactor Physics

    Ait Abderrahim, A.

    2002-01-01

    SCK-CEN's Reactor Physics and MYRRHA Department offers expertise in various areas of reactor physics, in particular in neutron and gamma calculations, reactor dosimetry, reactor operation and control, reactor code benchmarking and reactor safety calculations. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 materials testing reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2001 are summarised

  1. Reactor Physics

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  2. Reactor Physics

    Ait Abderrahim, A

    2002-04-01

    SCK-CEN's Reactor Physics and MYRRHA Department offers expertise in various areas of reactor physics, in particular in neutron and gamma calculations, reactor dosimetry, reactor operation and control, reactor code benchmarking and reactor safety calculations. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 materials testing reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2001 are summarised.

  3. Reactor Physics

    Ait Abderrahim, A.

    2001-01-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised

  4. Reactor operation

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  5. Reactor safeguards

    Russell, Charles R

    1962-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  6. A new approach to MgB2 superconducting magnet fabrication

    Miyazoe, A; Ando, T; Wada, H; Abe, H; Hirota, N; Sekino, M

    2008-01-01

    Fabrication of MgB 2 -based superconducting magnets has been attempted by a new approach using film coated on symmetric tubes. Superconducting MgB 2 films have been prepared on iron substrates by electroplating in molten electrolytes. The critical current (I c ) of the MgB 2 electroplating films at 4.2 K and at self-field was 15 A on the basis of 1 μV/cm of I c criterion. A model calculation has shown that MgB 2 -based superconducting magnets based on MgB 2 electroplating films have the potential to generate magnetic fields over 0.5 T

  7. Microstructure and mechanical properties investigation of in situ TiB2 and ZrB2 reinforced Al-4Cu composites

    Lutfi Anis, Ahmad; Ramli, Rosmamuhammadani; Darham, Widyani; Zakaria, Azlan; Talari, Mahesh Kumar

    2016-02-01

    Conventional Al-Cu alloys exhibit coarse grain structure leading to inferior mechanical properties in as-cast condition. Expensive thermo-mechanical treatments are needed to improve microstructure and corresponding mechanical properties. In situ Al-based composites were developed to improve mechanical properties by dispersion strengthening and grain refinement obtained by the presence of particulates in the melt during solidification. In this work Al-4Cu - 3TiB2 and Al-4Cu-3ZrB2 in situ composites were prepared by liquid casting method. XRD, electron microscopy and mechanical tests were performed on suitably sectioned and metallographically prepared surfaces to investigate the phase distribution, hardness and tensile properties. It was found that the reinforcement particles were segregated along the grain boundaries of Al dendrites. Tensile fracture morphology for both Al-4Cu - 3TiB2 and Al-4Cu-3ZrB2 were analyzed and compared to determine the fracture propagation mechanism in the composites. Al-4Cu-3ZrB2 in situ composites displayed higher strength and hardness compared to Al-4Cu-3TiB2 which could be ascribed to the stronger interfacial bonding between the Al dendrites and ZrB2 particulates as evidenced from fractographs.

  8. Transport properties and exponential n-values of Fe/MgB2 tapes with various MgB2 particle sizes

    Lezza, P.; Abaecherli, V.; Clayton, N.; Senatore, C.; Uglietti, D.; Suo, H.L.; Fluekiger, R.

    2004-01-01

    Fe/MgB 2 tapes have been prepared starting with pre-reacted binary MgB 2 powders. As shown by resistive and inductive measurements, the reduction of particle size to a few microns by ball milling has little influence on B c2 , while the superconducting properties of the individual MgB 2 grains are essentially unchanged. Reducing the particle size causes an enhancement of B irr from 14 to 16 T, while J c has considerably increased at high fields, its slope J c (B) being reduced. At 4.2 K, values of 5.3 x 10 4 and 1.2 x 10 3 A/cm 2 were measured at 3.5 and 10 T, respectively, suggesting a dominant role of the conditions at the grain interfaces. A systematic variation of these conditions at the interfaces is undertaken in order to determine the limit of transport properties for Fe/MgB 2 tapes. The addition of 5% Mg to MgB 2 powder was found to affect neither J c nor B c2 . For the tapes with the highest J c values, very high exponential n factors were measured: n=148, 89 and 17 at 3.5, 5 and 10 T, respectively and measurements of critical current versus applied strain have been performed. The mechanism leading to high transport critical current densities of filamentary Fe/MgB 2 tapes based on MgB 2 particles is discussed

  9. Ball-milling and AlB2 addition effects on the hydrogen sorption properties of the CaH2 + MgB2 system

    Schiavo, B.; Girella, A.; Agresti, F.; Capurso, G.; Milanese, C.

    2011-01-01

    Research highlights: → Calcium hydride + magnesium-aluminum borides as candidates for hydrogen storage. → Long time ball milling improves hydrogen sorption kinetics of the CaH 2 +MgB 2 system. → Coexistence of MgB 2 and AlB 2 does not improve hydrogen sorption performances. → Total substitution of MgB 2 with AlB 2 improves the system kinetics and reversibility. → Below 400 deg. C almost the full hydrogen capacity of the CaH 2 + AlB 2 system is reached. - Abstract: Among the borohydrides proposed for solid state hydrogen storage, Ca(BH 4 ) 2 is particularly interesting because of its favourable thermodynamics and relatively cheap price. Composite systems, where other species are present in addition to the borohydride, show some advantages in hydrogen sorption properties with respect to the borohydrides alone, despite a reduction of the theoretical storage capacity. We have investigated the milling time influence on the sorption properties of the CaH 2 + MgB 2 system from which Ca(BH 4 ) 2 and MgH 2 can be synthesized by hydrogen absorption process. Manometric and calorimetric measurements showed better kinetics for long time milled samples. We found that the total substitution of MgB 2 with AlB 2 in the starting material can improve the sorption properties significantly, while the co-existence of both magnesium and aluminum borides in the starting mixture did not cause any improvement. Rietveld refinements of the X-ray powder diffraction spectra were used to confirm the hypothesized reactions.

  10. Nuclear reactors

    Middleton, J.E.

    1977-01-01

    Reference is made to water cooled reactors and in particular to the cooling system of steam generating heavy water reactors (SGHWR). A two-coolant circuit is described for the latter. Full constructural details are given. (U.K.)

  11. Reactor decommissioning

    Lawton, H.

    1984-01-01

    A pioneering project on the decommissioning of the Windscale Advanced Gas-cooled Reactor, by the UKAEA, is described. Reactor data; policy; waste management; remote handling equipment; development; and recording and timescales, are all briefly discussed. (U.K.)

  12. Enhanced Constraints on theta13 from A Three-Flavor Oscillation Analysis of Reactor Antineutrinos at KamLAND

    The KamLAND Collaboration; Gando, A.; Gando, Y.; Ichimura, K.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Morikawa, T.; Nagai, N.; Nakajima, K.; Nakamura, K.; Narita, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Takahashi, H.; Takahashi, N.; Takemoto, Y.; Tamae, K.; Watanabe, H.; Xu, B. D.; Yabumoto, H.; Yoshida, H.; Yoshida, S.; Enomoto, S.; Kozlov, A.; Murayama, H.; Grant, C.; Keefer, G.; Piepke, A.; Banks, T. I.; Bloxham, T.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; Kadel, R.; O' Donnell, T.; Steiner, H. M.; Dwyer, D. A.; McKeown, R. D.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Sakai, M.; Horton-Smith, G. A.; Downum, K. E.; Gratta, G.; Efremenko, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Heeger, K. M.; Decowski, M. P.

    2010-09-24

    We present new constraints on the neutrino oscillation parameters {Delta}m{sub 21}{sup 2}, {theta}{sub 12}, and {theta}{sub 13} from a three-flavor analysis of solar and KamLAND data. The KamLAND data set includes data acquired following a radiopurity upgrade and amounts to a total exposure of 3.49 x 10{sup 32} target-proton-year. Under the assumption of CPT invariance, a two-flavor analysis ({theta}{sub 13} = 0) of the KamLAND and solar data yields the best-fit values tan{sup 2} {theta}{sub 12} = 0.444{sub -0.030}{sup +0.036} and {Delta}m{sub 21}{sup 2} = 7.50{sub -0.20}{sup +0.19} x 10{sup -5} eV{sup 2}; a three-flavor analysis with {theta}{sub 13} as a free parameter yields the best-fit values tan{sup 2} {theta}{sub 12} = 0.452{sub -0.033}{sup +0.035}, {Delta}m{sub 21}{sup 2} = 7.50{sub -0.20}{sup +0.19} x 10{sup -5}eV{sup 2}, and sin{sup 2} {theta}{sub 13} = 0.020{sub -0.016}{sup +0.016}. This {theta}{sub 13} interval is consistent with other recent work combining the CHOOZ, atmospheric and long-baseline accelerator experiments. We also present a new global {theta}{sub 13} analysis, incorporating the CHOOZ, atmospheric and accelerator data, which indicates sin{sup 2} {theta}{sub 13} = 0.017{sub -0.009}{sup +0.010}, a nonzero value at the 93% C.L. This finding will be further tested by upcoming accelerator and reactor experiments.

  13. RA Reactor

    1978-02-01

    In addition to basic characteristics of the RA reactor, organizational scheme and financial incentives, this document covers describes the state of the reactor components after 18 years of operation, problems concerned with obtaining the licence for operation with 80% fuel, problems of spent fuel storage in the storage pool of the reactor building and the need for renewal of reactor equipment, first of all instrumentation [sr

  14. Multiregion reactors

    Moura Neto, C. de; Nair, R.P.K.

    1979-08-01

    The study of reflected reactors can be done employing the multigroup diffusion method. The neutron conservation equations, inside the intervals, can be written by fluxes and group constants. A reflected reactor (one and two groups) for a slab geometry is studied, aplying the continuity of flux and current in the interface. At the end, the appropriated solutions for a infinite cylindrical reactor and for a spherical reactor are presented. (Author) [pt

  15. Nuclear reactor

    Hattori, Sadao; Sato, Morihiko.

    1994-01-01

    Liquid metals such as liquid metal sodium are filled in a reactor container as primary coolants. A plurality of reactor core containers are disposed in a row in the circumferential direction along with the inner circumferential wall of the reactor container. One or a plurality of intermediate coolers are disposed at the inside of an annular row of the reactor core containers. A reactor core constituted with fuel rods and control rods (module reactor core) is contained at the inside of each of the reactor core containers. Each of the intermediate coolers comprises a cylindrical intermediate cooling vessels. The intermediate cooling vessel comprises an intermediate heat exchanger for heat exchange of primary coolants and secondary coolants and recycling pumps for compulsorily recycling primary coolants at the inside thereof. Since a plurality of reactor core containers are thus assembled, a great reactor power can be attained. Further, the module reactor core contained in one reactor core vessel may be small sized, to facilitate the control for the reactor core operation. (I.N.)

  16. First-principles studies for the stability of a graphene-like boron layer on CrB2(0001) and MoB2(0001)

    Qin Na; Liu Shiyu; Li Zhen; Zhao Hui; Wang Sanwu

    2011-01-01

    With extensive first-principles density-functional-theory calculations, we investigate the stability and the atomic and electronic structures of the CrB 2 (0001) and MoB 2 (0001) surfaces, each with two different terminations. It is found that the boron-terminated surface is energetically more favorable over the wide range of thermodynamically allowed chemical potentials than the metal-terminated surface for both CrB 2 (0001) and MoB 2 (0001), suggesting a stable layer of graphene-like boron on the surfaces. Our results also show the similarities and the differences in relaxation and in bonding characteristics between the boron-terminated and metal-terminated surfaces.

  17. [[Length polymorphism of minisatellite repeat B2-VNTR of the bradykinin B2 receptor gene in healthy Russians and in patients with coronary heart disease].

    Suchkova, I O; Pavlinova, L I; Larionova, E E; Alenina, N V; Solov'ev, K V; Baranova, T V; Belotserkovskaia, E V; Sasina, L K; Bader, M; Denisenko, A D; Mustafina, O E; Khusnutdinova, E K; Patkin, E L

    2014-01-01

    Bradykinin B2 receptor is involved in many processes, including the regulation of blood pressure and smooth muscle contraction, vasodilation, inflammation, edema, cell proliferation, pain. It is suggested that this receptor may be one of the factors that have cardioprotective and infarct-limiting effects. It is assumed that certain genetic variants in both coding and non-coding regions ofBDKRB2 gene may influence its expression. In the 3'-untranslated region of BDKRB2 exon 3 the minisatellite repeat B2-VNTR is located. B2-VNTR has previously been shown to affect the BDKRB2 mRNA stability. Therefore, it is important to perform the molecular genetic analysis of this minisatellite in patients with different forms of coronary heart disease in order to reveal possible associations between specific B2-VNTR alleles and certain clinical forms of coronary heart disease. In the present study, a comparative analysis of the allele and genotype frequencies of B2-VNTR was carried out in groups of healthy individuals and patients with two clinical forms of coronary heart disease (angina pectoris and myocardial infarction), ethnically Russian. The results of the B2-VNTR length polymorphism analysis indicate that this tandem repeat may be attributed to a class of low polymorphic and non-hypervariable minisatellite. In all analyzed groups we revealed three B2-VNTR alleles, consisting of 43, 38 and 33 repeat units. Alleles of 43 and 33 repeats were major in all investigated groups. No statistically significant differences were found in the B2-VNTR allele and genotype frequencies between men and women in control group, and also between healthy men and men with angina pectoris and myocardial infarction. Thus, B2-VNTR length polymorphism was not associated with these clinical forms of coronary heart disease in Russian men. However, we do not exclude the possibility of association between the B2-VNTR short alleles (38 and 33 repeats) and cardioprotective effects of bradykinin B2 receptor

  18. Effects of TiB2 Particle and Short Fiber Sizes on the Microstructure and Properties of TiB2-Reinforced Composite Coatings

    Lin, Yinghua; Yao, Jianhua; Wang, Liang; Zhang, Qunli; Li, Xueqiao; Lei, Yongping; Fu, Hanguang

    2018-03-01

    In this study, particle and short fiber-reinforced titanium matrix composite coatings are prepared via laser in situ technique using (0.5 and 50 μm) TiB2 and Ti powder as cladding materials. The microstructure and properties of the composite coatings are studied, and the changing mechanism of the microstructure is discussed. The results reveal that particle agglomeration is prone to appear with using fine TiB2 particles. Decomposition of the particles preferentially occurs with using coarse TiB2 particles. The cracks and pores on the surface of the coating are formed at a lower laser energy density. With the increase in the laser energy density, cracking on the surface of the coating diminishes, but the coating exhibits depression behavior. The depression extent of the coating using fine TiB2 particle as the reinforcement is much less than that of the coating using coarse TiB2 particle. Moreover, the size of the aggregate and the tendency of cracking can be reduced with the increase in Ti addition. Meanwhile, short TiB fiber bundles are formed by the diffusion mechanism of rod aggregate, and randomly oriented TiB short fibers are formed mainly by the dissolution-precipitation mechanism of fine TiB2 particles. Moreover, the growth of short TiB fibers can be in an alternating manner between B27 and Bf structures. The micro-hardness and wear resistance of the coatings are evidently higher than that of the titanium alloy substrate. The wear resistance of the large size TiB2 coating is higher than that of the small size TiB2 coating under the condition of low load.

  19. Note: Progress on the use of MgB2 superconducting joint technique for the development of MgB2 magnets for magnetic resonance imaging (MRI).

    Kim, Y G; Song, J B; Kim, J C; Kim, J M; Yoo, B H; Yun, S B; Hwang, D Y; Lee, H G

    2017-08-01

    This note presents a superconducting joint technique for the development of MgB 2 magnetic resonance imaging (MRI) magnets. The MgB 2 superconducting joint was fabricated by a powder processing method using Mg and B powders to establish a wire-bulk-wire connection. The joint resistance measured using a field-decay method was magnets operating in the persistent current mode.

  20. Cloning and Expression of ORFV B2L Gene%羊口疮病毒B2L基因克隆及表达

    赵文博; 李瑞航; 贺鹏亮; 李朋娅; 王梦醒; 杨春华; 于永忠; 崔玉东

    2015-01-01

    为了获得羊口疮病毒囊膜蛋白。以羊口疮病毒基因组为模板,利用羊口疮病毒B2L基因特异性引物,进行PCR扩增,回收以及纯化PCR产物,连接到PMD18-T载体上,测序结果表明B2L基因全长1137 bp,编码379个氨基酸。再将B2L基因克隆至pET-30a,构建原核表达载体pET30a-B2L。经菌液PCR、酶切鉴定以及SDS-PAGE等方法表明成功构建原核表达载体,这将为今后的单抗制备以及羊口疮病毒的疫苗研究打下基础。%To obtain ORFV envelope protein and take ORFV genome as template,ORFV B2L gene was used as specific primers to amplify PCR and recovery and purify PCR products. Connected PCR products to PMD18-T vector,the sequence result showed that full-length of B2L gene was 1137 bp,and Encoding was 379 amino acids. B2L gene was cloned into pET-30a to construct prokaryotic expression vector pET30a-B2L. Prokaryotic expression vector was constructed by the methods of bacterium liquid PCR, enzyme identification and SDS-PAGE,which would provide the research basis of monoclonal antibody and ORFV vaccine in the future.

  1. Role of Erbin in ErbB2-dependent breast tumor growth

    Tao, Yanmei; Shen, Chengyong; Luo, Shiwen; Traoré, Wilfried; Marchetto, Sylvie; Santoni, Marie-Josée; Xu, Linlin; Wu, Biao; Shi, Chao; Mei, Jinghong; Bates, Ryan; Liu, Xihui; Zhao, Kai; Xiong, Wen-Cheng; Borg, Jean-Paul; Mei, Lin

    2014-01-01

    ErbB2 (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2), a receptor tyrosine kinase of the ErbB family, is overexpressed in around 25% of breast cancers. In addition to forming a heterodimer with other ErbB receptors in response to ligand stimulation, ErbB2 can be activated in a ligand-independent manner. We report here that Erbin, an ErbB2-interacting protein that was thought to act as an antitumor factor, is specifically expressed in mammary luminal epithelial cells and facilitates ErbB2-dependent proliferation of breast cancer cells and tumorigenesis in MMTV-neu transgenic mice. Disruption of their interaction decreases ErbB2-dependent proliferation, and deletion of the PDZ domain in Erbin hinders ErbB2-dependent tumor development in MMTV-neu mice. Mechanistically, Erbin forms a complex with ErbB2, promotes its interaction with the chaperon protein HSP90, and thus prevents its degradation. Finally, ErbB2 and Erbin expression correlates in human breast tumor tissues. Together, these observations establish Erbin as an ErbB2 regulator for breast tumor formation and progression. PMID:25288731

  2. Preparation and Microstructure of Porous ZrB2 Ceramics Using Reactive Spark Plasma Sintering Method

    YUAN Huiping; LI Junguo; SHEN Qiang; ZHANG Lianmeng

    2015-01-01

    Zirconium oxide (ZrO2) and boron carbide (B4C) were added to ZrB2 raw powders to prepare ZrB2 porous ceramics by reactive spark plasma sintering (RSPS). The reactions between ZrO2 and B4C which produce ZrB2 and gas (such as CO and B2O3) result in pore formation. X-Ray Diffraction results indicated that the products phase was ZrB2 and the reaction was completed after the RSPS process. The porosity could be controlled by changing the ratio of synthesized ZrB2 to raw ZrB2 powders. The porosity of porous ceramics with 20 wt% and 40 wt% synthsized ZrB2 are 0.185 and 0.222, respectivly. And dense ZrB2-SiC ceramic with a porosity of 0.057 was prepared under the same conditions for comparison. The pores were homogeneously distributed within the microstructure of the porous ceramics. The results indicate a promising method for preparing porous ZrB2-based ceramics.

  3. Microhardness and microstructure evolution of TiB2 reinforced Inconel 625/TiB2 composite produced by selective laser melting

    Zhang, Baicheng; Bi, Guijun; Nai, Sharon; Sun, Chen-nan; Wei, Jun

    2016-06-01

    In this study, micron-size TiB2 particles were utilized to reinforce Inconel 625 produced by selective laser melting. Exceptional microhardness 600-700 HV0.3 of the composite was obtained. In further investigation, the microstructure and mechanical properties of Inconel 625/TiB2 composite can be significantly influenced by addition of TiB2 particles during SLM. It was found that the long directional columnar grains observed from SLM-processed Inconel 625 were totally changed to fine dendritic matrix due to the addition of TiB2 particles. Moreover, with laser energy density (LED) of 1200 J/m, a Ti, Mo rich interface around TiB2 particles with fine thickness can be observed by FESEM and EDS. The microstructure evolution can be determined by different laser energy density (LED): under 1200 J/m, γ phase in dendrite grains; under 600 J/m, γ phase in combination of dendritic and acicular grains; under 400 J/m, γ phase acicular grains. Under optimized LED 1200 J/m, the dynamic nanohardness (8.62 GPa) and elastic modulus (167 GPa) of SLM-processed Inconel 625/TiB2 composite are higher compared with those of SLM-processed Inconel 625 (3.97 GPa and 135 GPa, respectively).

  4. Lattice Thermal Conductivity of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2 from Atomistic Simulations

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  5. Nuclear power reactors

    1982-11-01

    After an introduction and general explanation of nuclear power the following reactor types are described: magnox thermal reactor; advanced gas-cooled reactor (AGR); pressurised water reactor (PWR); fast reactors (sodium cooled); boiling water reactor (BWR); CANDU thermal reactor; steam generating heavy water reactor (SGHWR); high temperature reactor (HTR); Leningrad (RMBK) type water-cooled graphite moderated reactor. (U.K.)

  6. Research reactors

    Merchie, Francois

    2015-10-01

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  7. Reactor physics and reactor computations

    Ronen, Y.; Elias, E.

    1994-01-01

    Mathematical methods and computer calculations for nuclear and thermonuclear reactor kinetics, reactor physics, neutron transport theory, core lattice parameters, waste treatment by transmutation, breeding, nuclear and thermonuclear fuels are the main interests of the conference

  8. MgB2 thin films by hybrid physical-chemical vapor deposition

    Xi, X.X.; Pogrebnyakov, A.V.; Xu, S.Y.; Chen, K.; Cui, Y.; Maertz, E.C.; Zhuang, C.G.; Li, Qi; Lamborn, D.R.; Redwing, J.M.; Liu, Z.K.; Soukiassian, A.; Schlom, D.G.; Weng, X.J.; Dickey, E.C.; Chen, Y.B.; Tian, W.; Pan, X.Q.; Cybart, S.A.; Dynes, R.C.

    2007-01-01

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB 2 thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB 2 films. The epitaxial pure MgB 2 films grown by HPCVD show higher-than-bulk T c due to tensile strain in the films. The HPCVD films are the cleanest MgB 2 materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB 2 . The carbon-alloyed HPCVD films demonstrate record-high H c2 values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB 2 Josephson junctions

  9. Research reactors

    Kowarski, L.

    1955-01-01

    It brings together the techniques data which are involved in the discussion about the utility for a research institute to acquire an atomic reactor for research purposes. This type of decision are often taken by non-specialist people who can need a brief presentation of a research reactor and its possibilities in term of research before asking advises to experts. In a first part, it draws up a list of the different research programs which can be studied by getting a research reactor. First of all is the reactor behaviour and kinetics studies (reproducibility factor, exploration of neutron density, effect of reactor structure, effect of material irradiation...). Physical studies includes study of the behaviour of the control system, studies of neutron resonance phenomena and study of the fission process for example. Chemical studies involves the study of manipulation and control of hot material, characterisation of nuclear species produced in the reactor and chemical effects of irradiation on chemical properties and reactions. Biology and medicine research involves studies of irradiation on man and animals, genetics research, food or medical tools sterilization and neutron beams effect on tumour for example. A large number of other subjects can be studied in a reactor research as reactor construction material research, fabrication of radioactive sources for radiographic techniques or applied research as in agriculture or electronic. The second part discussed the technological considerations when choosing the reactor type. The technological factors, which are considered for its choice, are the power of the reactor, the nature of the fuel which is used, the type of moderator (water, heavy water, graphite or BeO) and the reflector, the type of coolants, the protection shield and the control systems. In the third part, it described the characteristics (place of installation, type of combustible and comments) and performance (power, neutron flux ) of already existing

  10. Preubiquitinated chimeric ErbB2 is constitutively endocytosed and subsequently degraded in lysosomes

    Vuong, Tram Thu [Institute of Clinical Medicine, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Berger, Christian [Department of Pathology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950 Nydalen, 0424 Oslo (Norway); Bertelsen, Vibeke; Rødland, Marianne Skeie [Institute of Clinical Medicine, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Stang, Espen [Department of Pathology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950 Nydalen, 0424 Oslo (Norway); Madshus, Inger Helene, E-mail: i.h.madshus@medisin.uio.no [Institute of Clinical Medicine, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Department of Pathology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950 Nydalen, 0424 Oslo (Norway)

    2013-02-01

    The oncoprotein ErbB2 is endocytosis-deficient, probably due to its interaction with Heat shock protein 90. We previously demonstrated that clathrin-dependent endocytosis of ErbB2 is induced upon incubation of cells with Ansamycin derivatives, such as geldanamycin and its derivative 17-AAG. Furthermore, we have previously demonstrated that a preubiquitinated chimeric EGFR (EGFR-Ub{sub 4}) is constitutively endocytosed in a clathrin-dependent manner. We now demonstrate that also an ErbB2-Ub{sub 4} chimera is endocytosed constitutively and clathrin-dependently. Upon expression, the ErbB2-Ub{sub 4} was further ubiquitinated, and by Western blotting, we demonstrated the formation of both Lys48-linked and Lys63-linked polyubiquitin chains. ErbB2-Ub{sub 4} was constitutively internalized and eventually sorted to late endosomes and lysosomes where the fusion protein was degraded. ErbB2-Ub{sub 4} was not cleaved prior to internalization. Interestingly, over-expression of Ubiquitin Interaction Motif-containing dominant negative fragments of the clathrin adaptor proteins epsin1 and Eps15 negatively affected endocytosis of ErbB2. Altogether, this argues that ubiquitination is sufficient to induce clathrin-mediated endocytosis and lysosomal degradation of the otherwise plasma membrane localized ErbB2. Also, it appears that C-terminal cleavage is not required for endocytosis. -- Highlights: ► A chimera containing ErbB2 and a tetra-Ubiquitin chain internalizes constitutively. ► Receptor fragmentation is not required for endocytosis of ErbB2. ► Ubiquitination is sufficient to induce endocytosis and degradation of ErbB2. ► ErbB2-Ub4 is internalized clathrin-dependently.

  11. Evolution, development, and communication of branding in B2B markets

    Seyedghorban, Zahra

    2017-01-01

    While, branding was traditionally viewed as having limited significance in business-to-business (B2B) markets, existing research not only acknowledges its existence, but emphasises its strategic importance in enhancing organisations’ competitive positions and financial performance. Given the fragmented research on B2B branding, there is a need to first provide a comprehensive review of B2B branding literature as a field of study by conducting a bibliometric investigation (Essay 1). The result...

  12. Preubiquitinated chimeric ErbB2 is constitutively endocytosed and subsequently degraded in lysosomes

    Vuong, Tram Thu; Berger, Christian; Bertelsen, Vibeke; Rødland, Marianne Skeie; Stang, Espen; Madshus, Inger Helene

    2013-01-01

    The oncoprotein ErbB2 is endocytosis-deficient, probably due to its interaction with Heat shock protein 90. We previously demonstrated that clathrin-dependent endocytosis of ErbB2 is induced upon incubation of cells with Ansamycin derivatives, such as geldanamycin and its derivative 17-AAG. Furthermore, we have previously demonstrated that a preubiquitinated chimeric EGFR (EGFR-Ub 4 ) is constitutively endocytosed in a clathrin-dependent manner. We now demonstrate that also an ErbB2-Ub 4 chimera is endocytosed constitutively and clathrin-dependently. Upon expression, the ErbB2-Ub 4 was further ubiquitinated, and by Western blotting, we demonstrated the formation of both Lys48-linked and Lys63-linked polyubiquitin chains. ErbB2-Ub 4 was constitutively internalized and eventually sorted to late endosomes and lysosomes where the fusion protein was degraded. ErbB2-Ub 4 was not cleaved prior to internalization. Interestingly, over-expression of Ubiquitin Interaction Motif-containing dominant negative fragments of the clathrin adaptor proteins epsin1 and Eps15 negatively affected endocytosis of ErbB2. Altogether, this argues that ubiquitination is sufficient to induce clathrin-mediated endocytosis and lysosomal degradation of the otherwise plasma membrane localized ErbB2. Also, it appears that C-terminal cleavage is not required for endocytosis. -- Highlights: ► A chimera containing ErbB2 and a tetra-Ubiquitin chain internalizes constitutively. ► Receptor fragmentation is not required for endocytosis of ErbB2. ► Ubiquitination is sufficient to induce endocytosis and degradation of ErbB2. ► ErbB2-Ub4 is internalized clathrin-dependently.

  13. Al-doped MgB_2 materials studied using electron paramagnetic resonance and Raman spectroscopy

    Bateni, Ali; Somer, Mehmet; Erdem, Emre; Repp, Sergej; Weber, Stefan

    2016-01-01

    Undoped and aluminum (Al) doped magnesium diboride (MgB_2) samples were synthesized using a high-temperature solid-state synthesis method. The microscopic defect structures of Al-doped MgB_2 samples were systematically investigated using X-ray powder diffraction, Raman spectroscopy, and electron paramagnetic resonance. It was found that Mg-vacancies are responsible for defect-induced peculiarities in MgB_2. Above a certain level of Al doping, enhanced conductive properties of MgB_2 disappear due to filling of vacancies or trapping of Al in Mg-related vacancy sites.

  14. Electronic and structural properties of TiB2: Bulk, surface, and nanoscale effects

    Volonakis, George; Tsetseris, Leonidas; Logothetidis, Stergios

    2011-01-01

    Titanium diboride (TiB 2 ), is a widely used hard material that comprises graphene-like layers of B and intercalated Ti atoms. Here we report the results of extensive first-principles calculations on key properties of bulk TiB 2 , TiB 2 surfaces, and TiB 2 nanocrystals (NCs). The computational approach is first validated based on the agreement between calculated structural and electronic properties of bulk TiB 2 and available experimental and theoretical data. We then obtain the formation energies for several surface cuts and use these values to construct TiB 2 NCs based on the Wulff theorem. Finally, we demonstrate by studying the adsorption of small molecules that hydrogen and oxygen adatoms can be attached through strongly exothermic chemisorption reactions on TiB 2 surfaces. Likewise, water molecules bind on various TiB 2 surfaces and NC facets, with an energetic preference for the latter. The results are relevant to applications that depend on reactivity-related TiB 2 properties, for example resistance to corrosion and interactions with water-based solutions.

  15. Study of preparation of TiB2 by TiC in Al melts

    Ding Haimin; Liu Xiangfa; Nie Jinfeng

    2012-01-01

    TiB 2 particles are prepared by TiC in Al melts and the characteristics of them are studied. It is found that TiC particles are unstable when boron exists in Al melts with high temperature and will transform to TiB 2 and Al 4 C 3 . Most of the synthesized TiB 2 particles are regular hexagonal prisms with submicron size. The diameter of the undersurfaces of these prisms is ranging from 200 nm to 1 μm and the height is ranging from 100 nm to 300 nm. It is considered that controlling the transformation from TiC to TiB 2 is an effective method to prepare small and uniform TiB 2 particles. - Highlights: ► TiC can easily transform into TiB 2 in Al melts. ► TiB 2 formed by TiC will grow into regular hexagonal prisms with submicron size. ► Controlling the transformation from TiC to TiB 2 is an effective method to prepare small and uniform TiB 2 particles.

  16. First-principles calculations for elastic properties of OsB2 under pressure

    Yang Junwei; Chen Xiangrong; Luo Fen; Ji Guangfu

    2009-01-01

    The structure, elastic properties and elastic anisotropy of orthorhombic OsB 2 are investigated by density functional theory method with the ultrasoft pseudopotential scheme in the frame of the generalized gradient approximation (GGA) as well as local density approximation (LDA). The obtained structural parameters, elastic constants, elastic anisotropy and Debye temperature for OsB 2 under pressure are consistent with the available experimental data and other theoretical results. It is found that the elastic constants, bulk modulus and Debye temperature of OsB 2 tend to increase with increasing pressure. It is predicted that OsB 2 is not a superhard material from our calculations.

  17. First-principles calculations for elastic properties of OsB 2 under pressure

    Yang, Jun-Wei; Chen, Xiang-Rong; Luo, Fen; Ji, Guang-Fu

    2009-11-01

    The structure, elastic properties and elastic anisotropy of orthorhombic OsB 2 are investigated by density functional theory method with the ultrasoft pseudopotential scheme in the frame of the generalized gradient approximation (GGA) as well as local density approximation (LDA). The obtained structural parameters, elastic constants, elastic anisotropy and Debye temperature for OsB 2 under pressure are consistent with the available experimental data and other theoretical results. It is found that the elastic constants, bulk modulus and Debye temperature of OsB 2 tend to increase with increasing pressure. It is predicted that OsB 2 is not a superhard material from our calculations.

  18. Chemically vapor-deposited ZrB2 as a selective solar absorber

    Randich, E.; Allred, D.D.

    1981-01-01

    Coatings of ZrB 2 and TiB 2 for photothermal solar absorber applications were prepared using chemical vapor deposition (CVD) techniques. Oxidation tests suggest a maximum temperature limit for air exposure of 600 K for TiB 2 and 800 K for ZrB 2 . Both materials exhibit innate spectral selectivity with an emittance at 375 K ranging from 0.06 to 0.09, a solar absorptance for ZrB 2 ranging from 0.67 to 0.77 and a solar absorptance for TiB 2 ranging from 0.46 to 0.59. ZrB 2 has better solar selectivity and more desirable oxidation behavior than TiB 2 . A 0.071 μm antireflection coating of Si 3 N 4 deposited onto the ZrB 2 coating leads to an increase in absorptance from 0.77 to 0.93, while the emittance remains unchanged. (Auth.)

  19. Structural, optical, and thermal properties of MAX-phase Cr2AlB2

    Li, Xiao-Hong; Cui, Hong-Ling; Zhang, Rui-Zhou

    2018-04-01

    First-principles calculations of the structural, optical, and thermal properties of Cr2AlB2 are performed using the pseudopotential plane-wave method within the generalized gradient approximation (GGA). Calculation of the elastic constant and phonon dispersion indicates that Cr2AlB2 is mechanically and thermodynamically stable. Analysis of the band structure and density of states indicates that Cr2AlB2 is metallic. The thermal properties under increasing temperature and pressure are investigated using the quasi-harmonic Debye model. The results show that anharmonic effects on Cr2AlB2 are important at low temperature and high pressure. The calculated equilibrium primitive cell volume is 95.91 Å3 at T = 300 K, P = 0 GPa. The ability of Cr2AlB2 to resist volume changes becomes weaker with increasing temperature and stronger with increasing pressure. Analysis of optical properties of Cr2AlB2 shows that the static dielectric function of Cr2AlB2 is 53.1, and the refractive index n 0 is 7.3. If the incident light has a frequency exceeding 16.09 eV, which is the plasma frequency of Cr2AlB2, Cr2AlB2 changes from metallic to dielectric material.

  20. The grain refinement behavior of TiB2 particles prepared with in situ technology

    Wang Chunlei; Wang Mingxing; Yu Benhai; Chen Dong; Qin Ping; Feng Minghai; Dai Qirun

    2007-01-01

    The grain-refining behavior of TiB 2 particles was investigated by the method of adding Al-4B master alloy into the melt of electrolytic low-titanium aluminum (ELTA). The results indicate that TiB 2 particles will be formed when the Al-4B master alloy is added into the melt of ELTA. These TiB 2 particles are produced by in situ technology, thus their surface properties are preserved and do not alter. At the bottom of the melt, the TiB 2 particles are pushed to the grain boundaries because of the absence of enough titanium atoms, which indicates that TiB 2 particles alone are not potent nuclei of α-Al. Though some TiB 2 particles settle down at the bottom, there are still numbers of fine TiB 2 particles suspended. These TiB 2 particles, together with the titanium atoms left, will form much more heterogeneous nucleation sites during the solidification of the melt, resulting in the grain-refining efficiency of the ELTA with Al-4B addition being improved obviously. To investigate the grain-refining mechanism of aluminum, this method has its advantages in comparison with that of adding synthetic TiB 2 particles into the melt of aluminum

  1. ErbB-2 nuclear function in breast cancer growth, metastasis and resistance to therapy.

    Elizalde, Patricia V; Cordo Russo, Rosalía I; Chervo, Maria F; Schillaci, Roxana

    2016-12-01

    Approximately 15-20% of breast cancers (BC) show either membrane overexpression of ErbB-2 (MErbB-2), a member of the ErbBs family of receptor tyrosine kinases, or ERBB2 gene amplification. Until the development of MErbB-2-targeted therapies, this BC subtype, called ErbB-2-positive, was associated with increased metastatic potential and poor prognosis. Although these therapies have significantly improved overall survival and cure rates, resistance to available drugs is still a major clinical issue. In its classical mechanism, MErbB-2 activates downstream signaling cascades, which transduce its effects in BC. The fact that ErbB-2 is also present in the nucleus of BC cells was discovered over twenty years ago. Also, compelling evidence revealed a non-canonical function of nuclear ErbB-2 as a transcriptional regulator. As a deeper understanding of nuclear ErbB-2 actions would be crucial to the disclosure of its role as a biomarker and a target of therapy in BC, we will here review its function in BC, in particular, its role in growth, metastatic spreading and response to currently available MErbB-2-positive BC therapies. © 2016 Society for Endocrinology.

  2. Usability perspective on social media sites' adoption in the B2B context

    Lacka, Ewelina; Chong, Alain

    2016-01-01

    While social media sites have been successfully adopted and used in the B2C context, they are perceived to be irrelevant in B2B marketing. This is due to marketers' perception of poor usability of these sites in the B2B sector. This study investigates the usability of social media sites when adopted for B2B marketing purposes in the one of world's largest social media market: China. Specifically, by extending the Technology Acceptance Model with Nielsen's Model of Attributes of System Accepta...

  3. Reactor container

    Naruse, Yoshihiro.

    1990-01-01

    The thickness of steel shell plates in a reactor container embedded in sand cussions is monitored to recognize the corrosion of the steel shell plates. That is, the reactor pressure vessel is contained in a reactor container shell and the sand cussions are disposed on the lower outside of the reactor container shell to elastically support the shell. A pit is disposed at a position opposing to the sand cussions for measuring the thickness of the reactor container shell plates. The pit is usually closed by a closing member. In the reactor container thus constituted, the closing member can be removed upon periodical inspection to measure the thickness of the shell plates. Accordingly, the corrosion of the steel shell plates can be recognized by the change of the plate thickness. (I.S.)

  4. Hybrid reactors

    Moir, R.W.

    1980-01-01

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of 233 U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m -2 , and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid

  5. Nuclear reactor

    Garabedian, G.

    1988-01-01

    A liquid reactor is described comprising: (a) a reactor vessel having a core; (b) one or more satellite tanks; (c) pump means in the satellite tank; (d) heat exchanger means in the satellite tank; (e) an upper liquid metal conduit extending between the reactor vessel and the satellite tank; (f) a lower liquid metal duct extending between the reactor vessel and satellite tanks the upper liquid metal conduit and the lower liquid metal duct being arranged to permit free circulation of liquid metal between the reactor vessel core and the satellite tank by convective flow of liquid metal; (g) a separate sealed common containment vessel around the reactor vessel, conduits and satellite tanks; (h) the satellite tank having space for a volume of liquid metal that is sufficient to dampen temperature transients resulting from abnormal operating conditions

  6. Neutron diffraction studies of magnetic ordering in superconducting ErNi2B2C and TmNi2B2C in an applied magnetic field

    Toft, Katrine Nørgaard

    The field-induced magnetic structures of ErNi2B2C and TmNi2B2C in are especially interesting because the field suppresses the superconducting order parameter and therefore the magnetic properties can be studied while varying the strength ofsuperconductivity. ErNi2B2C: For magnetic fields along all.......483,0,0). The appearance of the QN phase wasinitially believed to be caused by the suppression of superconductivity. This suppression should make it favorable to create a magnetic order with a Q-vector determined by the maximum in the magnetic susceptibility at the Fermi surface nesting vector QN.The phase diagram...... three symmetry directions, the observed magnetic structures have a period corresponding to the Fermi surface nesting structure. The phase diagrams present all the observed magnetic structures.Two results remain unresolved: 1. When applying the magnetic field along [010], the minority domain (QNB = (0,Q...

  7. Nuclear reactor

    Batheja, P.; Huber, R.; Rau, P.

    1985-01-01

    Particularly for nuclear reactors of small output, the reactor pressure vessel contains at least two heat exchangers, which have coolant flowing through them in a circuit through the reactor core. The circuit of at least one heat exchanger is controlled by a slide valve, so that even for low drive forces, particularly in natural circulation, the required even loading of the heat exchanger is possible. (orig./HP) [de

  8. Low-temperature synthesis of ZrB2 powder from oxides using Na

    Haruhiko Morito

    2017-12-01

    Full Text Available ZrB2 was synthesized by heating a mixture of ZrO2, B2O3, and Na in a molar ratio of 1:1:5 at 873–1273 K. While unreacted ZrO2 remained in the sample synthesized at 873 K, single phase ZrB2 powders were obtained at temperatures ≥1073 K. The diameters of the ZrB2 particles obtained at 1073 and 1273 K were 0.1–20 and 10–100 μm, respectively. Single phase ZrB2 was also obtained at 873 K when the starting material was rich in B2O3 and Na (ZrO2:B2O3:Na = 1:5:15. This route yielded fine particle aggregates of ZrB2, which were found to be <0.1 μm in size.

  9. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    2010-04-01

    ... media organizations. 9b.2 Section 9b.2 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS... employed by United States media organizations must: (a) Present to the Office of Press Relations... news media organizations; (3) Date of birth; (4) Place of birth; (5) Sex; (6) Citizenship; (7) Social...

  10. SerpinB2 is critical to Th2 immunity against enteric nematode infection

    SerpinB2, a member of the serine protease inhibitor family, is expressed by macrophages and up-regulated significantly by inflammation. Recent studies implicated a role for SerpinB2 in the control of Th1 and Th2 immune responses, but the mechanisms of these effects are unknown. In the current study...

  11. Formation of MgB2 at ambient temperature with an electrochemical process: a plausible mechanism

    Jadhav, A B; Subhedar, K M; Hyam, R S; Talaptra, A; Sen, Pintu; Bandyopadhyay, S K; Pawar, S H

    2005-01-01

    The binary intermetallic MgB 2 superconductor has been synthesized by many research groups. However, the mechanism of its formation is not clearly understood. In this communication, a comprehensive mechanism of the formation of MgB 2 from Le Chatelier's principle of equilibrium reaction has been explained both for solid-state reaction and electrodeposition methods. (rapid communication)

  12. In situ synthesis of NiAl–NbB2 composite powder through combustion synthesis

    Shokati, Ali Akbar; Parvin, Nader; Sabzianpour, Naser; Shokati, Mohammad; Hemmati, Ali

    2013-01-01

    Highlights: ► A Novel NiAl matrix composite powder with 0–40 wt.% NbB 2 was synthesized. ► Composite powders were synthesized by thermal explosion reaction of Ni–Al–Nb–B system. ► Microhardness of NiAl considerably increased with raising NbB 2 content. ► Synthesized composite powders is a good candidate as precursor for thermal barrier application. - Abstract: Synthesis of a novel NiAl matrix composite powder reinforced with 0–40 wt.% NbB 2 by combustion synthesis in thermal explosion mode was investigated. The elemental powders of Ni, Al, Nb, and amorphous boron were used as starting material. For all compositions final products consisted of only the NiAl and NbB 2 phases. Coarser NbB 2 with a relatively uniform distribution in NiAl matrix was formed with rising NbB 2 content. Microhardness of NiAl considerably increased from 377 ± 13 HV 0.05 to 866 ± 81 HV 0.05 for NiAl with 40 wt.% NbB 2 . High microhardness, proper size and distribution of NbB 2 in NiAl matrix make it a good candidate as precursor for thermal spray application.

  13. Neutron diffraction studies of Ho1-xYxNi2B2C compounds

    Chang, L.J.; Tomy, C.V.; Paul, D.M.K.

    1996-01-01

    Neutron diffraction measurements have been carried out to investigate the nature of magnetic ordering in Ho(1-x)Y(x)Ni(2)B(2)C (x = 0, 0.1 and 0.2) compounds. HoNi(2)B(2)C shows a complex type of magnetic ordering below the superconducting transition, with a commensurate antiferromagnetic ordering...

  14. Tissue-specific alternative splicing and expression of ATP1B2 gene ...

    After heat-stress, the expression levels of the different transcripts were lower in different tissues; however, the expression of the ATP1B2-complete transcript increased in heart and lung tissues. The results of this research provide some useful information for further studies into the function of the bovine ATP1B2 gene.

  15. Measurement of the anisotropy ratios in MgB2 single crystals

    Kim, Heon-Jung; Kang, Byeongwon; Lee, Hyun-Sook; Lee, Sung-Ik

    2006-01-01

    We present our recent measurements on the anisotropy ratios of MgB 2 single crystals. Our measurements indicate that the anisotropy ratios of the penetration depth and of the upper critical field have different magnitudes and temperature dependences, as predicted by theoretical calculations. These results imply that the two-gap nature can strongly influence the superconducting properties of MgB 2

  16. Theoretical study of superconductivity in MgB 2 and its alloys

    total density of states (DOS) and; the partial DOS around the Fermi energy, F, clearly show the importance of B -electrons for superconductivity. For BeB2 and NaB2, our results indicate qualitative similarities but significant quantitative differences in their electronic structure due to differences in the number of valence ...

  17. 26 CFR 1.6031(b)-2T - REMIC reporting requirements (temporary). [Reserved

    2010-04-01

    ... requirements (temporary). [Reserved] ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false REMIC reporting requirements (temporary). [Reserved] 1.6031(b)-2T Section 1.6031(b)-2T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE...

  18. 29 CFR 783.26 - The section 6(b)(2) minimum wage requirement.

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false The section 6(b)(2) minimum wage requirement. 783.26... The section 6(b)(2) minimum wage requirement. Section 6(b), with paragraph (2) thereof, requires the... prescribed by” paragraph (1) of the subsection is the minimum wage rate applicable according to the schedule...

  19. 17 CFR 270.24b-2 - Filing copies of sales literature.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Filing copies of sales literature. 270.24b-2 Section 270.24b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... literature. Copies of material filed with the Commission for the sole purpose of complying with section 24(b...

  20. Automated Report Generation for Research Data Repositories: From i2b2 to PDF.

    Thiemann, Volker S; Xu, Tingyan; Röhrig, Rainer; Majeed, Raphael W

    2017-01-01

    We developed an automated toolchain to generate reports of i2b2 data. It is based on free open source software and runs on a Java Application Server. It is sucessfully used in an ED registry project. The solution is highly configurable and portable to other projects based on i2b2 or compatible factual data sources.

  1. Heterogeneous reactors

    Moura Neto, C. de; Nair, R.P.K.

    1979-08-01

    The microscopic study of a cell is meant for the determination of the infinite multiplication factor of the cell, which is given by the four factor formula: K(infinite) = n(epsilon)pf. The analysis of an homogeneous reactor is similar to that of an heterogeneous reactor, but each factor of the four factor formula can not be calculated by the formulas developed in the case of an homogeneous reactor. A great number of methods was developed for the calculation of heterogeneous reactors and some of them are discussed. (Author) [pt

  2. Social Media within a B2B context : A qualitative study about how industrial corporations can use social media to maintain B2B relationships

    Andersén, Sophia; Bengtsson, Annie; Gilén, Sandra

    2014-01-01

    The last thirty years there has been a dramatic change in relationship marketing. The use of computers connected to the Internet at work places has increased over time and social media is widely used in marketing strategies. Social media is a new phenomenon to communicate with each other, it enables market information based on individual consumer’s experiences. Therefore managers are seeking a way to incorporate social media into their strategies, but this is more common within B2C than B2B. ...

  3. Dirac State in the FeB2 Monolayer with Graphene-Like Boron Sheet.

    Zhang, Haijun; Li, Yafei; Hou, Jianhou; Du, Aijun; Chen, Zhongfang

    2016-10-12

    By introducing the commonly utilized Fe atoms into a two-dimensional (2D) honeycomb boron network, we theoretically designed a new Dirac material of FeB 2 monolayer with a Fermi velocity in the same order of graphene. The electron transfer from Fe atoms to B networks not only effectively stabilizes the FeB 2 networks but also leads to the strong interaction between the Fe and B atoms. The Dirac state in FeB 2 system primarily arises from the Fe d orbitals and hybridized orbital from Fe-d and B-p states. The newly predicted FeB 2 monolayer has excellent dynamic and thermal stabilities and is also the global minimum of 2D FeB 2 system, implying its experimental feasibility. Our results are beneficial to further uncovering the mechanism of the Dirac cones and providing a feasible strategy for Dirac materials design.

  4. Nonlinear Elasticity of Borocarbide Superconductor YNi2B2C: A First-Principles Study

    Lili Liu

    2017-01-01

    Full Text Available First-principles calculations combined with homogeneous deformation methods are used to investigate the second- and third-order elastic constants of YNi2B2C with tetragonal structure. The predicted lattice constants and second-order elastic constants of YNi2B2C agree well with the available data. The effective second-order elastic constants are obtained from the second- and third-order elastic constants for YNi2B2C. Based on the effective second-order elastic constants, Pugh’s modulus ratio, Poisson’s ratio, and Vickers hardness of YNi2B2C under high pressure are further investigated. It is shown that the ductility of YNi2B2C increases with increasing pressure.

  5. Towards a Cryogen-Free MgB2-Based Superconducting Radio Frequency Accelerating Cavities

    Nassiri, Alireza

    Studies on the application of Magnesium diboride (MgB2) superconducting films have shown promise for use with the radio-frequency (SRF) accelerating cavities. MgB2\\ coating is a potential candidate to replace bulk niobium (Nb) SRF cavities. The ultimate goal of our research is to demonstrate MgB2 coating on copper cavities to allow operation at about 20 K or so as a result of the high transition temperature (Tc) of MgB2 and taking advantage of the excellent thermal conductivity of copper. Here, we will report on our recent experimental results of applying hybrid physical-chemical vapor deposition (HPCVD) to grow MgB2 films on 2-inch diameter copper discs as well as on a 2.8 GHz resonator cavity *Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06H11357.

  6. c-erbB-2 expression and benefit from adjuvant chemotherapy and radiotherapy of breast cancer

    Staal, O.; Sullivan, S.; Wingren, S.; Skoog, L.; Rutqvist, L.E.; Nordenskjoeld, B.; Carstensen, J.M.

    1995-01-01

    Frozen tissue from primary tumours of 152 premenopausal breast cancer patients, who participated in a trial comparing radiotherapy with adjuvant chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil, CMF), was analysed for c-erbB-2 protein expression, measured by flow cytometry. The relative risk of distant recurrence or death in the chemotherapy group as compared with the radiotherapy group was 3.0 (95% confidence interval (CI) 1.1-7.8) for patients whose tumours showed high c-erbB-2 levels and 0.87 (95% CI 0.43-1.7) for those with tumours with low levels of c-erbB-2 protein. Patients with highly proliferative tumours that did not overexpress c-erbB-2 benefited most, in terms of survival, from CMF. In addition, we found an increased risk of locoregional recurrence for tumours overexpressing c-erbB-2 when radiotherapy was replaced by chemotherapy. (author)

  7. Effects of sintering conditions on critical current properties and microstructures of MgB2 bulks

    Yamamoto, Akiyasu; Shimoyama, Jun-ichi; Ueda, Shinya; Katsura, Yukari; Iwayama, Isao; Horii, Shigeru; Kishio, Kohji

    2005-01-01

    The effects of heating conditions on critical current properties and microstructures of undoped MgB 2 bulks were systematically studied. Strong correlation was observed between J c and microstructures. The network structure with an excellent inter-grain connectivity of MgB 2 grains contributed to high-J c under low magnetic fields, and small grain size of MgB 2 enhanced the grain boundary flux pinning. Long time heating at low temperatures below the melting point of magnesium was discovered to be most effective for synthesis of MgB 2 bulks having strongly connected MgB 2 network structure with small grains. The sample heated at 550 deg. C for 1200 h recorded a high-J c of 4.02 x 10 5 A cm -2 at 20 K in self-field, while high-temperature and long time heating brought a significant grain growth which resulted in low J c

  8. Numerical study of the ITER divertor plasma with the B2-EIRENE code package

    Kotov, V.; Reiter, D. [Forschungszentrum Juelich (DE). Inst. fuer Energieforschung (IEF), Plasmaphysik (IEF-4); Kukushkin, A.S. [ITER International Team, Cadarache (France)

    2007-11-15

    The problem of plasma-wall interaction and impurity control is one of the remaining critical issues for development of an industrial energy source based on nuclear fusion of light isotopes. In this field sophisticated integrated numerical tools are widely used both for the analysis of current experiments and for predictions guiding future device design. The present work is dedicated to the numerical modelling of the edge plasma region in divertor configurations of large-scale tokamak fusion devices. A well established software tool for this kind of modelling is the B2-EIRENE code. It was originally developed for a relatively hot (>> 10 eV) ''high recycling divertor''. It did not take into account a number of physical effects which can be potentially important for ''detached conditions'' (cold, - several eV, - high density, - {approx} 10{sup 21} m{sup -3}, - plasma) typical for large tokamak devices. This is especially critical for the modelling of the divertor plasma of ITER: an international project of an experimental tokamak fusion reactor to be built in Cadarache, France by 2016. This present work is devoted to a major upgrade of the B2-EIRENE package, which is routinely used for ITER modelling, essentially with a significantly revised version of EIRENE: the Monte-Carlo neutral transport code. The main part of the thesis address three major groups of the new physical effects which have been added to the model in frame of this work: the neutral-neutral collisions, the up-to date hydrogen molecular reaction kinetics and the line radiation transport. The impact of the each stage of the upgrade on the self-consistent (between plasma, the neutral gas and the radiation field) solution for the reference ITER case is analysed. The strongest effect is found to be due to the revised molecular collision kinetics, in particular due to hitherto neglected elastic collisions of hydrogen molecules with ions. The newly added non

  9. Numerical study of the ITER divertor plasma with the B2-EIRENE code package

    Kotov, V.; Reiter, D.; Kukushkin, A.S.

    2007-11-01

    The problem of plasma-wall interaction and impurity control is one of the remaining critical issues for development of an industrial energy source based on nuclear fusion of light isotopes. In this field sophisticated integrated numerical tools are widely used both for the analysis of current experiments and for predictions guiding future device design. The present work is dedicated to the numerical modelling of the edge plasma region in divertor configurations of large-scale tokamak fusion devices. A well established software tool for this kind of modelling is the B2-EIRENE code. It was originally developed for a relatively hot (>> 10 eV) ''high recycling divertor''. It did not take into account a number of physical effects which can be potentially important for ''detached conditions'' (cold, - several eV, - high density, - ∼ 10 21 m -3 , - plasma) typical for large tokamak devices. This is especially critical for the modelling of the divertor plasma of ITER: an international project of an experimental tokamak fusion reactor to be built in Cadarache, France by 2016. This present work is devoted to a major upgrade of the B2-EIRENE package, which is routinely used for ITER modelling, essentially with a significantly revised version of EIRENE: the Monte-Carlo neutral transport code. The main part of the thesis address three major groups of the new physical effects which have been added to the model in frame of this work: the neutral-neutral collisions, the up-to date hydrogen molecular reaction kinetics and the line radiation transport. The impact of the each stage of the upgrade on the self-consistent (between plasma, the neutral gas and the radiation field) solution for the reference ITER case is analysed. The strongest effect is found to be due to the revised molecular collision kinetics, in particular due to hitherto neglected elastic collisions of hydrogen molecules with ions. The newly added non-linear effects (neutral-neutral collisions, radiation opacity

  10. Thermoluminescence kinetic parameters of different amount La-doped ZnB2O4

    Kucuk, Nil; Gozel, Aziz Halit; Yüksel, Mehmet; Dogan, Tamer; Topaksu, Mustafa

    2015-01-01

    The kinetic parameters of 1%, 2%, 3% and 4% La-doped ZnB 2 O 4 phosphors (i.e. ZnB 2 O 4 :0.01La, ZnB 2 O 4 :0.02La, ZnB 2 O 4 :0.03La and ZnB 2 O 4 :0.04La) synthesized by nitric acid method have been calculated. Thermoluminescence (TL) glow curves of ZnB 2 O 4 :La phosphors after beta-irradiation showed a very well defined main peak having the maximum temperature at around 200 °C and a shoulder peak at around 315 °C with a constant heating rate of 5 °C/s. The kinetic parameters of ZnB 2 O 4 :La phosphors TL glow peaks (i.e. order of kinetics (b), activation energies (E a ) and frequency factors (s)) have been determined and evaluated by Computerized Glow Curve Deconvolution (CGCD), and Peak Shape (PS) methods using the glow curve data. From the results, it can conclude that the values of E a obtained with these methods for ZnB 2 O 4 :La phosphors are consistent with each other, but the s values differ considerably. - Highlights: • Calculation of TL kinetic parameters for La-doped ZnB 2 O 4 . • La-doped ZnB 2 O 4 was synthesized by nitric acid method. • Well defined main peak at about 200 °C

  11. LytB1 and LytB2 of Mycobacterium tuberculosis Are Not Genetically Redundant.

    Amanda Claire Brown

    Full Text Available Mycobacterium tuberculosis synthesises isoprenoid precursors via the MEP/DOXP pathway and at least five enzymes in the pathway (Dxs1, Dxr/IspC, IspD, IspF, and GcpE/IspG are required for growth in vitro. We investigated the role of LytB (IspH in M. tuberculosis; M. tuberculosis is unusual in that it has two homologs-LytB1 and LytB2. We were unable to delete the lytB2 gene unless we provided an additional copy elsewhere, demonstrating that this is the essential homolog. We expressed lytB1 from the lytB2 promoter and confirmed that this could not complement for loss of function of lytB2, despite LytB1 possessing all the previously described conserved critical residues. Interestingly the sole LytB homolog of Mycobacterium smegmatis was able to compensate for loss of LytB2 in M. tuberculosis. We tested translational fusions of LytB1 and LytB2 for functionality in M. tuberculosis, but only a fusion with 90% N-terminal LytB2 and 10% C-terminal LytB1 was functional. In order to identify the key difference between the two proteins, site directed mutagenesis was used to change LytB2 residues into their counterparts in LytB1. None of these amino acid substitutions was essential for function and all lytB2 mutant alleles were functional. In contrast, mutation of the key residues for [Fe4S4] cluster formation, as well as a catalytic residue in LytB1 did not result in functional complementation. Thus, although LytB1 and LytB2 are not genetically redundant, this is not dependent on small amino acid changes, but is likely to be a result of major overall structural differences.

  12. Dual-Layer Oxidation-Protective Plasma-Sprayed SiC-ZrB2/Al2O3-Carbon Nanotube Coating on Graphite

    Ariharan, S.; Sengupta, Pradyut; Nisar, Ambreen; Agnihotri, Ankur; Balaji, N.; Aruna, S. T.; Balani, Kantesh

    2017-02-01

    Graphite is used in high-temperature gas-cooled reactors because of its outstanding irradiation performance and corrosion resistance. To restrict its high-temperature (>873 K) oxidation, atmospheric-plasma-sprayed SiC-ZrB2-Al2O3-carbon nanotube (CNT) dual-layer coating was deposited on graphite substrate in this work. The effect of each layer was isolated by processing each component of the coating via spark plasma sintering followed by isothermal kinetic studies. Based on isothermal analysis and the presence of high residual thermal stress in the oxide scale, degradation appeared to be more severe in composites reinforced with CNTs. To avoid the complexity of analysis of composites, the high-temperature activation energy for oxidation was calculated for the single-phase materials only, yielding values of 11.8, 20.5, 43.5, and 4.5 kJ/mol for graphite, SiC, ZrB2, and CNT, respectively, with increased thermal stability for ZrB2 and SiC. These results were then used to evaluate the oxidation rate for the composites analytically. This study has broad implications for wider use of dual-layer (SiC-ZrB2/Al2O3) coatings for protecting graphite crucibles even at temperatures above 1073 K.

  13. Adoption of the B2SAFE EUDAT replication service by the EPOS community

    Cacciari, Claudio; Fares, Massimo; Fiameni, Giuseppe; Michelini, Alberto; Danecek, Peter; Wittenburg, Peter

    2014-05-01

    B2SAFE is the EUDAT service for moving and replicating data between sites and storage systems for different purposes. The goal of B2SAFE is to keep the data from a repository safe by replicating it across different geographical and administrative zones according to a set of well-defined policies. It is also a way to store large volumes of data permanently at those sites which are providing powerful on-demand data analysis facilities. In particular, B2SAFE operates on the domain of registered data where data objects are referable via persistent identifiers (PIDs). B2SAFE is more than just copying data because the PIDs must be carefully managed when data objects are moved or replicated. The EUDAT B2SAFE Service offers functionality to replicate datasets across different data centres in a safe and efficient way while maintaining all information required to easily find and query information about the replica locations. The information about the replica locations and other important information is stored in PID records, each managed in separate administrative domains. The B2SAFE Service is implemented as an iRODS module providing a set of iRODS rules or policies to interface with the EPIC handle API and uses the iRODS middleware to replicate datasets from a source data (or community) centre to a destination data centre. The definition of the dataset(s) to replicate is flexible and up to the communities using the B2SAFE service. While the B2SAFE is internally using the EPIC handle API, communities have the choice to use any PID system they prefer to assign PIDs to their digital objects. A reference to one or more EUDAT B2SAFE PIDs is returned by the B2SAFE service when a dataset is replicated. The presentation will introduce the problem space of B2SAFE, presents the achievements that have been made during the last year for enabling communities to make use of the B2SAFE service, demonstrates a EPOS use cases, outlines the commonalities and differences between the policies

  14. Slurry reactors

    Kuerten, H; Zehner, P [BASF A.G., Ludwigshafen am Rhein (Germany, F.R.)

    1979-08-01

    Slurry reactors are designed on the basis of empirical data and model investigations. It is as yet not possible to calculate the flow behavior of such reactors. The swarm of gas bubbles and cluster formations of solid particles and their interaction in industrial reactors are not known. These effects control to a large extent the gas hold-up, the gas-liquid interface and, similarly as in bubble columns, the back-mixing of liquids and solids. These hydrodynamic problems are illustrated in slurry reactors which constructionally may be bubble columns, stirred tanks or jet loop reactors. The expected effects are predicted by means of tests with model systems modified to represent the conditions in industrial hydrogenation reactors. In his book 'Mass Transfer in Heterogeneous Catalysis' (1970) Satterfield complained of the lack of knowledge about the design of slurry reactors and hence of the impossible task of the engineer who has to design a plant according to accepted rules. There have been no fundamental changes since then. This paper presents the problems facing the engineer in designing slurry reactors, and shows new development trends.

  15. Reactor safety

    Butz, H.P.; Heuser, F.W.; May, H.

    1985-01-01

    The paper comprises an introduction into nuclear physics bases, the safety concept generally speaking, safety devices of pwr type reactors, accident analysis, external influences, probabilistic safety assessment and risk studies. It further describes operational experience, licensing procedures under the Atomic Energy Law, research in reactor safety and the nuclear fuel cycle. (DG) [de

  16. Nuclear reactor

    Mysels, K.J.; Shenoy, A.S.

    1976-01-01

    A nuclear reactor is described in which the core consists of a number of fuel regions through each of which regulated coolant flows. The coolant from neighbouring fuel regions is combined in a manner which results in an averaging of the coolant temperature at the outlet of the core. By this method the presence of hot streaks in the reactor is reduced. (UK)

  17. Reactor container

    Kato, Masami; Nishio, Masahide.

    1987-01-01

    Purpose: To prevent the rupture of the dry well even when the melted reactor core drops into a reactor pedestal cavity. Constitution: In a reactor container in which a dry well disposed above the reactor pedestal cavity for containing the reactor pressure vessel and a torus type suppression chamber for containing pressure suppression water are connected with each other, the pedestal cavity and the suppression chamber are disposed such that the flow level of the pedestal cavity is lower than the level of the pressure suppression water. Further, a pressure suppression water introduction pipeway for introducing the pressure suppression water into the reactor pedestal cavity is disposed by way of an ON-OFF valve. In case if the melted reactor core should fall into the pedestal cavity, the ON-OFF valve for the pressure suppression water introduction pipeway is opened to introduce the pressure suppression water in the suppression chamber into the pedestal cavity to cool the melted reactor core. (Ikeda, J.)

  18. RA Reactor

    1989-01-01

    This chapter includes the following: General description of the RA reactor, organization of work, responsibilities of leadership and operators team, regulations concerning operation and behaviour in the reactor building, regulations for performing experiments, regulations and instructions for inserting samples into experimental channels [sr

  19. Reactor physics

    Ait Abderrahim, H.

    1998-01-01

    Progress in research on reactor physics in 1997 at the Belgian Nuclear Research Centre SCK/CEN is described. Activities in the following four domains are discussed: core physics, ex-core neutron transport, experiments in Materials Testing Reactors, international benchmarks

  20. Reactor core

    Azekura, Kazuo; Kurihara, Kunitoshi.

    1992-01-01

    In a BWR type reactor, a great number of pipes (spectral shift pipes) are disposed in the reactor core. Moderators having a small moderating cross section (heavy water) are circulated in the spectral shift pipes to suppress the excess reactivity while increasing the conversion ratio at an initial stage of the operation cycle. After the intermediate stage of the operation cycle in which the reactor core reactivity is lowered, reactivity is increased by circulating moderators having a great moderating cross section (light water) to extend the taken up burnup degree. Further, neutron absorbers such as boron are mixed to the moderator in the spectral shift pipe to control the concentration thereof. With such a constitution, control rods and driving mechanisms are no more necessary, to simplify the structure of the reactor core. This can increase the fuel conversion ratio and control great excess reactivity. Accordingly, a nuclear reactor core of high conversion and high burnup degree can be attained. (I.N.)

  1. Reactor container

    Fukazawa, Masanori.

    1991-01-01

    A system for controlling combustible gases, it has been constituted at present such that the combustible gases are controlled by exhausting them to the wet well of a reactor container. In this system, however, there has been a problem, in a reactor container having plenums in addition to the wet well and the dry well, that the combustible gases in such plenums can not be controlled. In view of the above, in the present invention, suction ports or exhaust ports of the combustible gas control system are disposed to the wet well, the dry well and the plenums to control the combustible gases in the reactor container. Since this can control the combustible gases in the entire reactor container, the integrity of the reactor container can be ensured. (T.M.)

  2. Reactor container

    Kojima, Yoshihiro; Hosomi, Kenji; Otonari, Jun-ichiro.

    1997-01-01

    In the present invention, a catalyst for oxidizing hydrogen to be disposed in a reactor container upon rupture of pipelines of a reactor primary coolant system is prevented from deposition of water droplets formed from a reactor container spray to suppress elevation of hydrogen concentration in the reactor container. Namely, a catalytic combustion gas concentration control system comprises a catalyst for oxidizing hydrogen and a support thereof. In addition, there is also disposed a water droplet deposition-preventing means for preventing deposition of water droplets in a reactor pressure vessel on the catalyst. Then, the effect of the catalyst upon catalytic oxidation reaction of hydrogen can be kept high. The local elevation of hydrogen concentration can be prevented even upon occurrence of such a phenomenon that various kinds of mobile forces in the container such as dry well cooling system are lost. (I.S.)

  3. Nuclear reactor

    Tilliette, Z.

    1975-01-01

    A description is given of a nuclear reactor and especially a high-temperature reactor in which provision is made within a pressure vessel for a main cavity containing the reactor core and a series of vertical cylindrical pods arranged in spaced relation around the main cavity and each adapted to communicate with the cavity through two collector ducts or headers for the primary fluid which flows downwards through the reactor core. Each pod contains two superposed steam-generator and circulator sets disposed in substantially symmetrical relation on each side of the hot primary-fluid header which conveys the primary fluid from the reactor cavity to the pod, the circulators of both sets being mounted respectively at the bottom and top ends of the pod

  4. Aspirin Hydrolysis in Plasma Is a Variable Function of Butyrylcholinesterase and Platelet-activating Factor Acetylhydrolase 1b2 (PAFAH1b2)*

    Zhou, Gang; Marathe, Gopal K.; Hartiala, Jaana; Hazen, Stanley L.; Allayee, Hooman; Tang, W. H. Wilson; McIntyre, Thomas M.

    2013-01-01

    Aspirin is rapidly hydrolyzed within erythrocytes by a heterodimer of PAFAH1b2/PAFAH1b3 but also in plasma by an unidentified activity. Hydrolysis in both compartments was variable, with a 12-fold variation in plasma among 2226 Cleveland Clinic GeneBank patients. Platelet inhibition by aspirin was suppressed in plasma that rapidly hydrolyzed aspirin. Plasma aspirin hydrolysis was significantly higher in patients with coronary artery disease compared with control subjects (16.5 ± 4.4 versus 15.1 ± 3.7 nmol/ml/min; p = 3.4 × 10−8). A genome-wide association study of 2054 GeneBank subjects identified a single locus immediately adjacent to the BCHE (butyrylcholinesterase) gene associated with plasma aspirin hydrolytic activity (lead SNP, rs6445035; p = 9.1 × 10−17). However, its penetrance was low, and plasma from an individual with an inactivating mutation in BCHE still effectively hydrolyzed aspirin. A second aspirin hydrolase was identified in plasma, the purification of which showed it to be homomeric PAFAH1b2. This is distinct from the erythrocyte PAFAH1b2/PAFAH1b3 heterodimer. Inhibitors showed that both butyrylcholinesterase (BChE) and PAFAH1b2 contribute to aspirin hydrolysis in plasma, with variation primarily reflecting non-genetic variation of BChE activity. Therefore, aspirin is hydrolyzed in plasma by two enzymes, BChE and a new extracellular form of platelet-activating factor acetylhydrolase, PAFAH1b2. Hydrolytic effectiveness varies widely primarily from non-genetic variation of BChE activity that affects aspirin bioavailability in blood and the ability of aspirin to inhibit platelet aggregation. PMID:23508960

  5. Aspirin hydrolysis in plasma is a variable function of butyrylcholinesterase and platelet-activating factor acetylhydrolase 1b2 (PAFAH1b2).

    Zhou, Gang; Marathe, Gopal K; Hartiala, Jaana; Hazen, Stanley L; Allayee, Hooman; Tang, W H Wilson; McIntyre, Thomas M

    2013-04-26

    Aspirin is rapidly hydrolyzed within erythrocytes by a heterodimer of PAFAH1b2/PAFAH1b3 but also in plasma by an unidentified activity. Hydrolysis in both compartments was variable, with a 12-fold variation in plasma among 2226 Cleveland Clinic GeneBank patients. Platelet inhibition by aspirin was suppressed in plasma that rapidly hydrolyzed aspirin. Plasma aspirin hydrolysis was significantly higher in patients with coronary artery disease compared with control subjects (16.5 ± 4.4 versus 15.1 ± 3.7 nmol/ml/min; p = 3.4 × 10(-8)). A genome-wide association study of 2054 GeneBank subjects identified a single locus immediately adjacent to the BCHE (butyrylcholinesterase) gene associated with plasma aspirin hydrolytic activity (lead SNP, rs6445035; p = 9.1 × 10(-17)). However, its penetrance was low, and plasma from an individual with an inactivating mutation in BCHE still effectively hydrolyzed aspirin. A second aspirin hydrolase was identified in plasma, the purification of which showed it to be homomeric PAFAH1b2. This is distinct from the erythrocyte PAFAH1b2/PAFAH1b3 heterodimer. Inhibitors showed that both butyrylcholinesterase (BChE) and PAFAH1b2 contribute to aspirin hydrolysis in plasma, with variation primarily reflecting non-genetic variation of BChE activity. Therefore, aspirin is hydrolyzed in plasma by two enzymes, BChE and a new extracellular form of platelet-activating factor acetylhydrolase, PAFAH1b2. Hydrolytic effectiveness varies widely primarily from non-genetic variation of BChE activity that affects aspirin bioavailability in blood and the ability of aspirin to inhibit platelet aggregation.

  6. Half-metallic magnetism in Ti3Co5-xFexB2

    Rohit Pathak

    2017-05-01

    Full Text Available Bulk alloys and thin films of Fe-substituted Ti3Co5B2 have been investigated by first-principle density-functional calculations. The series, which is of interest in the context of alnico magnetism and spin electronics, has been experimentally realized in nanostructures but not in the bulk. Our bulk calculations predict paramagnetism for Ti3Co5B2, Ti3Co4FeB2 and Ti3CoFe4B2, whereas Ti3Fe5B2 is predicted to be ferromagnetic. The thin films are all ferromagnetic, indicating that moment formation may be facilitated at nanostructural grain boundaries. One member of the thin-film series, namely Ti3CoFe4B2, is half-metallic and exhibits perpendicular easy-axis magnetic anisotropy. The half-metallicity reflects the hybridization of the Ti, Fe and Co 3d orbitals, which causes a band gap in minority spin channel, and the limited equilibrium solubility of Fe in bulk Ti3Co5B2 may be linked to the emerging half-metallicity due to Fe substitution.

  7. SrBeB2O5: Growth, crystal structure and optical properties

    Yao, Wenjiao; Wang, Xiaoshan; Huang, Hongwei; Xu, Tao; Jiang, Xingxing; Wang, Xiaoyang; Lin, Zheshuai; Chen, Chuangtian

    2014-01-01

    Graphical abstract: The crystal displays a layered configuration along c axis with the wrinkled infinite (BeB 2 O 5 ) ∞ layers. Display Omitted - Highlights: • A new beryllium borate SrBeB 2 O 5 was synthesized. • A layered structure (BeB 2 O 5 ) ∞ was formed by BO 3 triangles and B/BeO 4 tetrahedrons. • SrBeB 2 O 5 has a very wide transparency range of wavelengths from 200 nm to 1800 nm. • A-site ions impact greatly on the structures of beryllium borates. - Abstract: A novel beryllium borate SrBeB 2 O 5 is discovered for the first time through traditional solid state reaction and high temperature solution method. The framework of the structure is composed by two-dimensional [BeB 2 O 5 ] layers determined from single-crystal X-ray diffraction data. The further structural analysis of beryllium borates reveals that the arrangement of anionic groups attributes to the structural stability. Moreover, the influences of the A-site cations on the structural features of fundamental building blocks in the alkaline or alkaline earth beryllium borates are discussed. The UV–Vis–NIR diffuse-reflectance pattern reveals that this compound has a very wide transparency range of wavelengths down to 200 nm. In addition, the properties of SrBeB 2 O 5 were also characterized by powder X-ray diffraction, differential scanning calorimetry, and IR spectroscopy

  8. MgB2 thick films on three-dimensional structures fabricated by HPCVD

    Guo, Zhengshan; Cai, Xingwei; Liao, Xuebin; Chen, Yiling; Yang, Can; Niu, Ruirui; Luo, Wenhao; Huang, Zigeng; Feng, Qingrong; Gan, Zizhao

    2018-06-01

    Magnetic shielding has been a key factor in the measurement of ultra-weak magnetic fields, especially for shielding from low frequency electromagnetic noise. With the recent development of superconducting quantum interference devices, superconducting magnetic shielding has become an important area of research. MgB2 has shown great potential in magnetic shielding for its remarkable superconducting properties, the feasibility of its use in this capacity having been demonstrated by MgB2 bulk samples. However, the potential for application of such bulk samples is limited. In this work, we have investigated the possibility of the fabrication of MgB2 films on three-dimensional (3D) structures using a hybrid physical‑chemical vapor deposition system. MgB2 films 10 μm thick have been fabricated on the outer surface of a polycrystalline Al2O3 cylinder. The deposited film showed a transition temperature (TC) of 39 K and J C of 5.1 × 105 A · cm‑2, which are comparable to those of planar MgB2 films. This work shows the feasibility of depositing MgB2 films onto a 3D structure, and sheds light on the potential use of MgB2 films in superconducting magnetic shielding.

  9. Platelet thromboxane B2-formation in end-stage kidney disease and after kidney transplantation

    Stefanovic, V.; Lecic, N.

    1986-01-01

    The aim of this work was to analyse TxB 2 formation by platelets in endstage kidney disease patients and in kidney graft recipients. Four groups of patients were studied: 12 preterminal chronic renal failure patients, 42 patients on maintenance hemodialysis, 8 patients on CAPD and 11 grafted patients. TxB 2 production by platelets was determined in serum following spontaneous blood clotting for 1/2 h at 37 0 C. Hemodialysis patients generated 80.7 ± 9.6 ng/ml (mean ± S.E.M.) of TxB 2 which was significantly (p 2 formation in hemodialysis patients had no relationship with the residual kidney function. Patients on CAPD produced 65.0 ± 12.7 ng/ml of TxB 2 . Very low TxB 2 generation was obtained also in preterminal chronic renal failure patients (57.0 ± 11.8 ng/ml). Kidney graft recipients had a mean TxB 2 production of 81.6 ± 24.2 ng/ml with a range from 12.5-200 ng/ml. Very low TxB 2 was formed in grafted patients with renal failure. (orig.) [de

  10. Antitumor and angiostatic activities of the antimicrobial peptide dermaseptin B2.

    van Zoggel, Hanneke; Carpentier, Gilles; Dos Santos, Célia; Hamma-Kourbali, Yamina; Courty, José; Amiche, Mohamed; Delbé, Jean

    2012-01-01

    Recently, we have found that the skin secretions of the Amazonian tree frog Phyllomedusa bicolor contains molecules with antitumor and angiostatic activities and identified one of them as the antimicrobial peptide dermaseptin (Drs) B2. In the present study we further explored the in vitro and in vivo antitumor activity of this molecule and investigated its mechanism of action. We showed that Drs B2 inhibits the proliferation and colony formation of various human tumor cell types, and the proliferation and capillary formation of endothelial cells in vitro. Furthermore, Drs B2 inhibited tumor growth of the human prostate adenocarcinoma cell line PC3 in a xenograft model in vivo. Research on the mechanism of action of Drs B2 on tumor PC3 cells demonstrated a rapid increasing amount of cytosolic lactate dehydrogenase, no activation of caspase-3, and no changes in mitochondrial membrane potential. Confocal microscopy analysis revealed that Drs B2 can interact with the tumor cell surface, aggregate and penetrate the cells. These data together indicate that Drs B2 does not act by apoptosis but possibly by necrosis. In conclusion, Drs B2 could be considered as an interesting and promising pharmacological and therapeutic leader molecule for the treatment of cancer.

  11. Antitumor and angiostatic activities of the antimicrobial peptide dermaseptin B2.

    Hanneke van Zoggel

    Full Text Available Recently, we have found that the skin secretions of the Amazonian tree frog Phyllomedusa bicolor contains molecules with antitumor and angiostatic activities and identified one of them as the antimicrobial peptide dermaseptin (Drs B2. In the present study we further explored the in vitro and in vivo antitumor activity of this molecule and investigated its mechanism of action. We showed that Drs B2 inhibits the proliferation and colony formation of various human tumor cell types, and the proliferation and capillary formation of endothelial cells in vitro. Furthermore, Drs B2 inhibited tumor growth of the human prostate adenocarcinoma cell line PC3 in a xenograft model in vivo. Research on the mechanism of action of Drs B2 on tumor PC3 cells demonstrated a rapid increasing amount of cytosolic lactate dehydrogenase, no activation of caspase-3, and no changes in mitochondrial membrane potential. Confocal microscopy analysis revealed that Drs B2 can interact with the tumor cell surface, aggregate and penetrate the cells. These data together indicate that Drs B2 does not act by apoptosis but possibly by necrosis. In conclusion, Drs B2 could be considered as an interesting and promising pharmacological and therapeutic leader molecule for the treatment of cancer.

  12. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A.; (UPENN-MED)

    2009-09-25

    The orphan receptor tyrosine kinase ErbB2 (also known as HER2 or Neu) transforms cells when overexpressed, and it is an important therapeutic target in human cancer. Structural studies have suggested that the oncogenic (and ligand-independent) signalling properties of ErbB2 result from the absence of a key intramolecular 'tether' in the extracellular region that autoinhibits other human ErbB receptors, including the epidermal growth factor (EGF) receptor. Although ErbB2 is unique among the four human ErbB receptors, here we show that it is the closest structural relative of the single EGF receptor family member in Drosophila melanogaster (dEGFR). Genetic and biochemical data show that dEGFR is tightly regulated by growth factor ligands, yet a crystal structure shows that it, too, lacks the intramolecular tether seen in human EGFR, ErbB3 and ErbB4. Instead, a distinct set of autoinhibitory interdomain interactions hold unliganded dEGFR in an inactive state. All of these interactions are maintained (and even extended) in ErbB2, arguing against the suggestion that ErbB2 lacks autoinhibition. We therefore suggest that normal and pathogenic ErbB2 signalling may be regulated by ligands in the same way as dEGFR. Our findings have important implications for ErbB2 regulation in human cancer, and for developing therapeutic approaches that target novel aspects of this orphan receptor.

  13. Anticonvulsant activity of B2, an adenosine analog, on chemical convulsant-induced seizures.

    Min Li

    Full Text Available Epilepsy is a chronic neurological disorder characterized by recurrent seizures. However, approximately one-third of epilepsy patients still suffer from uncontrolled seizures. Effective treatments for epilepsy are yet to be developed. N (6-(3-methoxyl-4-hydroxybenzyl adenine riboside (B2 is a N(6-substitued adenosine analog. Here we describe an investigation of the effects and mechanisms of B2 on chemical convulsant-induced seizures. Seizures were induced in mice by administration of 4-aminopyridine (4-AP, pentylenetetrazol (PTZ, picrotoxin, kainite acid (KA, or strychnine. B2 has a dose-related anticonvulsant effect in these chemical-induced seizure models. The protective effects of B2 include increased latency of seizure onset, decreased seizure occurrence, shorter seizure duration and reduced mortality rate. Radioligand binding and cAMP accumulation assays indicated that B2 might be a functional ligand for both adenosine A1 and A2A receptors. Furthermore, DPCPX, a selective A1 receptor antagonist, but not SCH58261, a selective A2A receptor antagonist, blocked the anticonvulsant effect of B2 on PTZ-induced seizure. c-Fos is a cellular marker for neuronal activity. Immunohistochemical and western blot analyses indicated that B2 significantly reversed PTZ-induced c-Fos expression in the hippocampus. Together, these results indicate that B2 has significant anticonvulsant effects. The anticonvulsant effects of B2 may be attributed to adenosine A1 receptor activation and reduced neuronal excitability in the hippocampus. These observations also support that the use of adenosine receptor agonist may be a promising approach for the treatment of epilepsy.

  14. Procyanidin dimer B2-mediated IRAK-M induction negatively regulates TLR4 signaling in macrophages

    Sung, Nak-Yun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Yang, Mi-So [Department of Microbiology, Infection Signaling Network Research Center, College of Medicine, Chungnam National University, Daejeon (Korea, Republic of); Song, Du-Sub [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); School of life sciences and Biotechnology, Korea University 5-ka, Anam-Dong, Sungbuk-ku, Seoul 136-701 (Korea, Republic of); Kim, Jae-Kyung; Park, Jong-Heum; Song, Beom-Seok; Park, Sang-Hyun; Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Park, Hyun-Jin [School of life sciences and Biotechnology, Korea University 5-ka, Anam-Dong, Sungbuk-ku, Seoul 136-701 (Korea, Republic of); Kim, Jae-Hun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Byun, Eui-Baek, E-mail: ebbyun80@kaeri.re.kr [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Byun, Eui-Hong, E-mail: ehbyun80@kongju.ac.k [Department of Food Science and Technology, Kongju National University, Yesan 340-800 (Korea, Republic of)

    2013-08-16

    Highlights: •Pro B2 elevated the expression of IRAK-M, a negative regulator of TLR signaling. •LPS-induced expression of cell surface molecules was inhibited by Pro B2. •LPS-induced production of pro-inflammatory cytokines was inhibited by Pro B2. •Pro B2 inhibited LPS-induced activation of MAPKs and NF-κB through IRAK-M. •Pro B2 inactivated naïve T cells by inhibiting LPS-induced cytokines via IRAK-M. -- Abstract: Polyphenolic compounds have been found to possess a wide range of physiological activities that may contribute to their beneficial effects against inflammation-related diseases; however, the molecular mechanisms underlying this anti-inflammatory activity are not completely characterized, and many features remain to be elucidated. In this study, we investigated the molecular basis for the down-regulation of toll-like receptor 4 (TLR4) signal transduction by procyanidin dimer B2 (Pro B2) in macrophages. Pro B2 markedly elevated the expression of the interleukin (IL)-1 receptor-associated kinase (IRAK)-M protein, a negative regulator of TLR signaling. Lipopolysaccharide (LPS)-induced expression of cell surface molecules (CD80, CD86, and MHC class I/II) and production of pro-inflammatory cytokines (tumor necrosis factor-α, IL-1β, IL-6, and IL-12p70) were inhibited by Pro B2, and this action was prevented by IRAK-M silencing. In addition, Pro B2-treated macrophages inhibited LPS-induced activation of mitogen-activated protein kinases such as extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase and the translocation of nuclear factor κB and p65 through IRAK-M. We also found that Pro B2-treated macrophages inactivated naïve T cells by inhibiting LPS-induced interferon-γ and IL-2 secretion through IRAK-M. These novel findings provide new insights into the understanding of negative regulatory mechanisms of the TLR4 signaling pathway and the immune-pharmacological role of Pro B2 in the immune response against the development

  15. B2B-uutiskirjeen visuaalisen ilmeen kehitys — Case Tamtron Solutions Oy

    Salo, Sari

    2014-01-01

    Opinnäytetyön tarkoituksena oli kehittää Tamtron Solutions Oy:n uutiskirjeelle uusi visuaalinen ilme. Yrityksen lähettämästä uutiskirjeestä yritysasiakkaille puhutaan B2B-uutiskirjeenä. Tamtron Solutions Oy halusi B2B-uutiskirjeen avulla tehostaa markkinointia, kasvattaa myyntiä ja luoda uusia asiakassuhteita. Yritys halusi toteuttaa markkinointikampanjan B2B-uutiskirjeen muodossa rakennusalan yrityksille. Yritys valitsi kampanjan kohderyhmäksi rakennusalan yritykset, koska lakimuutos rakennu...

  16. Growth of high quality large area MgB2 thin films by reactive evaporation

    Moeckly, Brian H.; Ruby, Ward S.

    2006-01-01

    We report a new in-situ reactive deposition thin film growth technique for the production of MgB2 thin films which offers several advantages over all existing methods and is the first deposition method to enable the production of high-quality MgB2 films for real-world applications. We have used this growth method, which incorporates a rotating pocket heater, to deposit MgB2 films on a variety of substrates, including single-crystalline, polycrystalline, metallic, and semiconductor materials u...

  17. First principle study of UHTC ternary diboride, Cr2AlB2

    Rastogi, Anugya; Rajpoot, Priyanka; Verma, U. P.

    2018-04-01

    In this paper ab-initio study of the structural, electronic and optical properties of ternary metal boride Cr2AlB2 using full potential linear augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). The study of structural properties shows that Cr2AlB2 is metallic in nature and have orthorhombic crystal structure. The optical properties show that it possess anisotropic behavior, which have wide applications in electricity production through concentration of solar power (CSP) technology. To the best of our knowledge, theoretical study of the optical properties of Cr2AlB2 is reported for the first time.

  18. Strategic B2B customer experience management: the importance of outcomes-based measures

    Zolkiewski, Judy; Story, Victoria; Burton, Jamie; Chan, Paul; Gomes, Andre; Hunter-Jones, Philippa; O’Malley, Lisa; Peters, Linda D.; Raddats, Chris; Robinson, William

    2017-01-01

    Purpose\\ud \\ud The purpose of this paper is to critique the adequacy of efforts to capture the complexities of customer experience in a business-to-business (B2B) context using input–output measures. The paper introduces a strategic customer experience management framework to capture the complexity of B2B service interactions and discusses the value of outcomes-based measurement.\\ud Design/methodology/approach\\ud \\ud This is a theoretical paper that reviews extant literature related to B2B cu...

  19. Using service design methods for B2b service brand concept development: Case company

    Molina Escalante, Hugo

    2014-01-01

    A short time before this study was initiated, a small B2b service company had just began op-erating its business without a brand of it’s own. The company owners were looking to design an innovative brand for their business. The purpose of this thesis was to develop the brand for this service Company in the B2b context, using practical service design and Strategic design research methods. This thesis report represents a framework for developing a B2b service brand using research methods c...

  20. Soliton cellular automaton associated with Dn(1)-crystal B2,s

    Misra, Kailash C.; Wilson, Evan A.

    2013-04-01

    A solvable vertex model in ferromagnetic regime gives rise to a soliton cellular automaton which is a discrete dynamical system in which site variables take on values in a finite set. We study the scattering of a class of soliton cellular automata associated with the U_q(D_n^{(1)})-perfect crystal B2, s. We calculate the combinatorial R matrix for all elements of B2, s ⊗ B2, 1. In particular, we show that the scattering rule for our soliton cellular automaton can be identified with the combinatorial R matrix for U_q(A_1^{(1)}) oplus U_q(D_{n-2}^{(1)})-crystals.

  1. Improving magnetic properties of MgB_2 bulk superconductors by synthetic engine oil treatment

    Taylan Koparan, E.; Savaskan, B.; Yanmaz, E.

    2016-01-01

    Highlights: • The effects of synthetic engine oil treatment on magnetic properties of bulk MgB_2 superconductors has been first time investigated and reported. • Synthetic engine oil used as a product which is cheap and a rich carbon source obviously has improved the superconducting magnetic properties of MgB_2. • The critical current density of all of MgB_2 samples immersed at different standby time in engine oil in whole field range has been better than that of the pure MgB_2 sample. • The MgB_2 sample immersed at 300 min standby time in synthetic engine oil has the best performance compared to other samples. - Abstract: The present study focuses on the effects of standby time of the MgB_2 samples immersed in synthetic engine oil on the critical current density ( J_c(H)), magnetic field dependence of the pinning force density f_p(b) and T_c performances of MgB_2 bulk superconductors. Synthetic engine oil was used as a product which is cheap and a rich carbon source. Manufactured MgB_2 pellet samples were immersed at different standby time of 30 min, 120 min, 300 min and 1440 min in synthetic engine oil after the first heating process. Finally, MgB_2 samples immersed in synthetic engine oil were sintered at 1000 °C and kept for 15 min in Ar atmosphere. The critical current density of all of MgB_2 samples immersed at different standby time in engine oil in whole field range was better than that of the pure MgB_2 sample because of the number of the pinning centers. The MgB_2 sample immersed at 300 min standby time in synthetic engine oil has the best performance compared to other samples. The J_c value for the pure sample is 2.0 × 10"3 A/cm"2, whereas for the MgB_2 sample immersed at 300 min standby time in engine oil the J_c is enhanced to 4.8 × 10"3 A/cm"2 at 5 K and 3 T. The superconducting transition temperature (T_c) did not change with the increasing standby time of the samples in synthetic engine oil at all. The best diamagnetic property was

  2. Reactor building

    Maruyama, Toru; Murata, Ritsuko.

    1996-01-01

    In the present invention, a spent fuel storage pool of a BWR type reactor is formed at an upper portion and enlarged in the size to effectively utilize the space of the building. Namely, a reactor chamber enhouses reactor facilities including a reactor pressure vessel and a reactor container, and further, a spent fuel storage pool is formed thereabove. A second spent fuel storage pool is formed above the auxiliary reactor chamber at the periphery of the reactor chamber. The spent fuel storage pool and the second spent fuel storage pool are disposed in adjacent with each other. A wall between both of them is formed vertically movable. With such a constitution, the storage amount for spent fuels is increased thereby enabling to store the entire spent fuels generated during operation period of the plant. Further, since requirement of the storage for the spent fuels is increased stepwisely during periodical exchange operation, it can be used for other usage during the period when the enlarged portion is not used. (I.S.)

  3. Reactor container

    Shibata, Satoru; Kawashima, Hiroaki

    1984-01-01

    Purpose: To optimize the temperature distribution of the reactor container so as to moderate the thermal stress distribution on the reactor wall of LMFBR type reactor. Constitution: A good heat conductor (made of Al or Cu) is appended on the outer side of the reactor container wall from below the liquid level to the lower face of a deck plate. Further, heat insulators are disposed to the outside of the good heat conductor. Furthermore, a gas-cooling duct is circumferentially disposed at the contact portion between the good heat conductor and the deck plate around the reactor container. This enables to flow the cold heat from the liquid metal rapidly through the good heat conductor to the cooling duct and allows to maintain the temperature distribution on the reactor wall substantially linear even with the abrupt temperature change in the liquid metal. Further, by appending the good heat conductor covered with inactive metals not only on the outer side but also on the inside of the reactor wall to introduce the heat near the liquid level to the upper portion and escape the same to the cooling layer below the roof slab, the effect can be improved further. (Ikeda, J.)

  4. Data of evolutionary structure change: 1CG5B-2ZLWD [Confc[Archive

    Full Text Available 1CG5B-2ZLWD 1CG5 2ZLW B D VKLSEDQEHYIKGVWKDVDHKQITAKALERVFVVYPWTT.../seq1> VQLSGEEKAAVLALWDKVNEEEVGGEALGRLLVVYPWTQRFFDSFGDLSNPGAVMGNPKVKAHGKKVLHSFGEGVHHLDNLKGTFAALSELHCDK...224 GLY CA 259 2ZLW D 2ZLWD...W D 2ZLWD ELHCDKLHVDP

  5. Data of evolutionary structure change: 1CG8B-2ZLWD [Confc[Archive

    Full Text Available 1CG8B-2ZLWD 1CG8 2ZLW B D VKLSEDQEHYIKGVWKDVDHKQITAKALERVFVVYPWTT.../seq1> VQLSGEEKAAVLALWDKVNEEEVGGEALGRLLVVYPWTQRFFDSFGDLSNPGAVMGNPKVKAHGKKVLHSFGEGVHHLDNLKGTFAALSELHCDK... GLY CA 249 2ZLW D 2ZLWD...2ZLW D 2ZLWD ELHCDKLHVDP

  6. Phthalocyanine doping to improve critical current densities in MgB2 tapes

    Zhang Xianping; Ma Yanwei; Wang Dongliang; Gao Zhaoshun; Wang Lei; Qi Yanpeng; Awaji, Satoshi; Watanabe, Kazuo; Mossang, Eric

    2009-01-01

    Phthalocyanine-doped MgB 2 tapes were prepared by the in situ powder-in-tube method. The relationships between the critical current properties, crystallinity and microstructure were studied as a function of the phthalocyanine doping level. It is found that both H irr and H c2 were improved when MgB 2 samples were doped with phthalocyanine, which are mainly attributed to the effective carbon substitution and enhanced flux pinning strength caused by very fine grain sizes. Furthermore, compared to pure samples, the MgO content remained almost unchanged in all doped tapes, which is very beneficial to having better grain connectivity in MgB 2 . Significantly improved J c was obtained in the phthalocyanine-doped MgB 2 tapes, especially under high magnetic fields.

  7. Tissue-specific alternative splicing and expression of ATP1B2 gene

    user6

    2012-05-15

    May 15, 2012 ... retention; these isoforms were found in liver, kidney, muscle and breast tissues. ... lower levels than the complete ATP1B2 gene transcript in all the ... temperature. ... growth, differentiation, and disease (Zhou et al., 2002;.

  8. Progress in the deposition of MgB2 thin films

    Xi, X X; Pogrebnyakov, A V; Zeng, X H; Redwing, J M; Xu, S Y; Li, Qi; Liu, Zi-Kui; Lettieri, J; Vaithyanathan, V; Schlom, D G; Christen, H M; Zhai, H Y; Goyal, A

    2004-01-01

    An MgB 2 thin film deposition technology is the first critical step in the development of superconducting electronics utilizing the 39 K superconductor. It turned out to be a challenging task due to the volatility of Mg and phase stability of MgB 2 , the low sticking coefficients of Mg at elevated temperatures, and the reactivity of Mg with oxygen. A brief overview of current deposition techniques is provided here from a thermodynamic perspective, with an emphasis on a very successful technique for high quality in situ epitaxial MgB 2 films, the hybrid physical-chemical vapour deposition. Examples of heterostructures of MgB 2 with other materials are also presented

  9. The Importance of Brand on B2B Markets: Expert Interviews with Hilti AG Managers

    Martin Konečný

    2013-12-01

    Full Text Available This paper investigates the importance of brand building in the business-to-business world. Not only B2C companies must take branding into account and put it among their top priorities in order to survive and succeed on the market. The first part of the article deals with the theoretical background of brand importance and market specifics of B2B markets and results in the setting of two hypotheses. The following research has to find out how the managers of a pure business-to-business company perceive the importance of a brand; moreover, it has to evaluate the importance of eight specific brand building factors. Fourteen expert interviews document the growing of brands in the B2B market and their main aspects. At the end of the article, we will focus on future implications for B2B management.

  10. Molecular-Beam Epitaxially Grown MgB2 Thin Films and Superconducting Tunnel Junctions

    Jean-Baptiste Laloë

    2011-01-01

    Full Text Available Since the discovery of its superconducting properties in 2001, magnesium diboride has generated terrific scientific and engineering research interest around the world. With a of 39 K and two superconducting gaps, MgB2 has great promise from the fundamental point of view, as well as immediate applications. Several techniques for thin film deposition and heterojunction formation have been established, each with its own advantages and drawbacks. Here, we will present a brief overview of research based on MgB2 thin films grown by molecular beam epitaxy coevaporation of Mg and B. The films are smooth and highly crystalline, and the technique allows for virtually any heterostructure to be formed, including all-MgB2 tunnel junctions. Such devices have been characterized, with both quasiparticle and Josephson tunneling reported. MgB2 remains a material of great potential for a multitude of further characterization and exploration research projects and applications.

  11. Data of evolutionary structure change: 1VL8B-2UVDE [Confc[Archive

    Full Text Available 1VL8B-2UVDE 1VL8 2UVD B E VFDLRGRVALVTGGSRGLGFGIAQGLAEAGCSVVVASRN...seq1> --MLKGKVALVTGASRGIGRAIAIDLAKQGANVVVNYAGNEQKANEVVDEIKKL-GSDAIAVRADVANA...D E 2UVDE VNYAGNEQKAN E 2UVDE EIKKL-GSDAI 2 2UVD E 2UVDE

  12. Lectin receptor kinase LecRK-b2 localizes to plasma membrane and ...

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... Furthermore, the recombinant LecRK-b2 protein exhibited autophosphorylation ... absence of ligand (Giranton et al., 2000; Shimosato et al.,. 2007), while some ..... Elicitin and Mediates INF1-induced Cell Death. Planta, 228: ...

  13. Controlled indole-3-acetaldoxime production through ethanol-induced expression of CYP79B2

    Mikkelsen, M.D.; Fuller, V.L.; Hansen, Bjarne Gram

    2009-01-01

    Indole-3-acetaldoxime (IAOx) is a key branching point between primary and secondary metabolism. IAOx serves as an intermediate in the biosynthesis of indole glucosinolates (I-GLSs), camalexin and the plant hormone indole-3-acetic acid (IAA). The cytochrome P450s CYP79B2 and CYP79B3 catalyze......OH)-inducible CYP79B2 construct into double (cyp79b2 cyp79b3) or triple (cyp79b2 cyp79b3 cyp83b1) mutant lines. We show EtOH-dependent induction of camalexin and identify a number of candidate IAA homeostasis- or defense-related genes by clustered microarray analysis. The transgenic mutant lines are thus promising...

  14. Gibberellic acid, amino acids (glycine and L-leucine), vitamin B2 ...

    SAM

    2014-03-14

    Mar 14, 2014 ... vitamin B2 and zinc as factors affecting the production pigments by Monascus ..... in a nitrogen-deficient medium, the B-group vitamins, both single ... citrinin production in the industrial important strain Monascus purpureus ...

  15. Investigations into the PbO-TeO2-B2O3 glass system

    Basariya, F.P.; Gugushvili, G.M.

    1975-01-01

    Based on the results of investigations of the system A-TeO 2 -B 2 O 3 and from the ternary phase diagram a region is determined of stable nonorganic glasses of the system PbO-TeO 2 -B 2 O 3 noncrystallizable at a temperature of 300 0 C and showing satisfactory chemical stability, as well as satisfactory isolation properties up to 300 0 C. On addition of an optimum amount of tellurium oxide one can obtain low-melting glasses with a temperature interval of 250-300 0 C. It is established that the substitution of PbO by TeO 2 or B 2 O 3 , or TeO 2 by B 2 O 3 leads to a decrease in the glass density. (author)

  16. Novel Peptide/Protein Delivery System Targeting erbB2-Overexpressing Breast Cancer Cells

    Yu, Dihua

    2002-01-01

    .... During this funding year, we focused on the delivery of erbB2 signal-blocking ESP peptides (objective 2) . Because of the complexity of biotin-penetratin-AHNP-ESP, the synthesis was unsuccessful...

  17. Safety Analysis Report: X17B2 beamline Synchrotron Medical Research Facility

    Gmuer, N.F.; Thomlinson, W.

    1990-02-01

    This report contains a safety analysis for the X17B2 beamline synchrotron medical research facility. Health hazards, risk assessment and building systems are discussed. Reference is made to transvenous coronary angiography

  18. Pressure induced structural phase transition of OsB 2: First-principles calculations

    Ren, Fengzhu; Wang, Yuanxu; Lo, V. C.

    2010-04-01

    Orthorhombic OsB 2 was synthesized at 1000 °C and its compressibility was measured by using the high-pressure X-ray diffraction in a Diacell diamond anvil cell from ambient pressure to 32 GPa [R.W. Cumberland, et al. (2005)]. First-principles calculations were performed to study the possibility of the phase transition of OsB 2. An analysis of the calculated enthalpy shows that orthorhombic OsB 2 can transfer to the hexagonal phase at 10.8 GPa. The calculated results with the quasi-harmonic approximation indicate that this phase transition pressure is little affected by the thermal effect. The calculated phonon band structure shows that the hexagonal P 6 3/ mmc structure (high-pressure phase) is stable for OsB 2. We expect the phase transition can be further confirmed by the experimental work.

  19. 1300 micron continuum observations of the Sagittarius B2 molecular cloud core

    Goldsmith, P.F.; Snell, R.L.; Lis, D.C.

    1987-01-01

    Observations with 23-arcsec angular resolution are obtained of the continuum emission at 1300 microns wavelength from the central region of the Sgr B2 molecular cloud, which contains the north and middle high-mass star-forming regions and associated radio continuum and maser sources. The spatial resolution of the present data shows that the 1300-micron continuum emission peak is located at Sgr B2(N), in contrast to the midinfrared emission, which is centered on Sgr B2(M). Comparison with 53 micron data having comparable angular resolution suggests that there is optically thick foreground dust which prevents detection of Sgr B2(N) at wavelengths not greater than 100 microns. Within the about 1.5 x 3.5 pc region mapped, the total mass is 500,000 solar masses and the mean H2 density is 300,000/cu cm, somewhat larger than found in previous investigations. 27 references

  20. Successful treatment of hereditary angioedema with bradykinin B2-receptor antagonist icatibant.

    Krause, Karoline; Metz, Martin; Zuberbier, Torsten; Maurer, Marcus; Magerl, Markus

    2010-04-01

    The bradykinin B2 receptor antagonist icatibant has recently become available for treating hereditary angioedema. Our observations demonstrate icatibant to be effective and safe for the treatment of both, abdominal and cutaneous attacks in a practice setting beyond clinical studies.

  1. Evidence of diketopiperazine and oxazolone structures for HA b2+ ion.

    Perkins, Brittany R; Chamot-Rooke, Julia; Yoon, Sung Hwan; Gucinski, Ashley C; Somogyi, Arpád; Wysocki, Vicki H

    2009-12-09

    Peptide fragmentation can lead to an oxazolone or diketopiperazine b(2)(+) ion structure. IRMPD spectroscopy combined with computational modeling and gas-phase H/D exchange was used to study the structure of the b(2)(+) ion from protonated HAAAA. The experimental spectrum of the b(2)(+) ion matches both the experimental spectrum for the protonated cyclic dipeptide HA (a commercial diketopiperazine) and the theoretical spectrum for a diketopiperazine protonated at the imidazole pi nitrogen. A characteristic band at 1875 cm(-1) and increased abundance of the peaks at 1619 and 1683 cm(-1) indicate a second population corresponding to an oxazolone species. H/D exchange also shows a mixture of two populations consistent with a mixture of b(2)(+) ion diketopiperazine and oxazolone structures.

  2. Nuclear reactor

    Rau, P.

    1980-01-01

    The reactor core of nuclear reactors usually is composed of individual elongated fuel elements that may be vertically arranged and through which coolant flows in axial direction, preferably from bottom to top. With their lower end the fuel elements gear in an opening of a lower support grid forming part of the core structure. According to the invention a locking is provided there, part of which is a control element that is movable along the fuel element axis. The corresponding locking element is engaged behind a lateral projection in the opening of the support grid. The invention is particularly suitable for breeder or converter reactors. (orig.) [de

  3. Development of MgB2 superconductor wire with high critical current

    Kim, Chan Joong; Jun, Byung Hyuk; Park, Soon Dong; Kim, Nam Kyu; Kim, Yi Jeong; Yi, Ji Hye; Lee, Ji Hyun; Tan, Kai Sin

    2009-07-01

    The MgB 2 superconductor with smaller grain size could improve its critical properties by providing flux pinning centers with high grain boundary density. The effects of C doping such as charcoal, paper ash and glycerin on the superconducting properties was investigated for in situ processed MgB 2 samples using low purity semi-crystalline B powder. The results show a decrease in Tc and an enhancement of Jc at high fields for the C-doped samples as compared to the un-doped samples. A combined process of a mechanical ball milling and liquid glycerin (C 3 H 8 O 3 ) treatment of B powder has been conducted to enhance the superconducting properties of MgB 2 . The mechanical ball milling was effective for grain refinement, and a lattice disorder was easily achieved by glycerin addition. With the combined process, the critical properties was further increased due to a higher grain boundary density and a greater C substitution. To get fine grain structure of MgB 2 with high critical current properties, mechanical milling for as-received B powder and low temperature solid-state reaction of 550 or 600 .deg. C were attempted to in situ powder-in-tube processed MgB 2 /Fe wires. The critical current properties of the MgB 2 wires using the milled B powder were enhanced due to a smaller grain size and an increased volume of the superconducting phase. The solid-state reaction of a low temperature process for the samples using the milled B powder resulted in a poorer crystallinity with a smaller grain size, which improved superconducting properties. We established the system to measure the transport current properties of the MgB 2 wires. The field dependence of the transport Jc was evaluated for the MgB 2 wires heat-treated at different heat treatment conditions using ball-milled and glycerin-treated B powder. The MgB 2 magnet was developed and the AC loss of MgB 2 wire was also investigated. A conduction cooling device to cool the MgB 2 coil down to 4 K has been fabricated and the

  4. Exceptional quantum subgroups for the rank two Lie algebras B2 and G2

    Coquereaux, R.; Tahri, E.H.

    2010-01-01

    Exceptional modular invariants for the Lie algebras B2 (at levels 2,3,7,12) and G2 (at levels 3,4) can be obtained from conformal embeddings. We determine the associated alge bras of quantum symmetries and discover or recover, as a by-product, the graphs describing exceptional quantum subgroups of type B2 or G2 which encode their module structure over the associated fusion category. Global dimensions are given.

  5. Magnetism and superconductivity in ErNi2B2C

    in modulation vector and harmonic content. Studies of the vortex lattice show the presence of a 45. ◦ reorientation transition and a distorted hexagonal to square transition as a function of applied field. Further distortions of the vortex lattice occur at TN, but no changes are seen at TF. Keywords. (RE)Ni2B2C; ErNi2B2C; vortex ...

  6. Drivers of relationships affecting B2B firms in an e-commerce environment

    Irene Samanta

    2014-09-01

    Full Text Available The advent of the internet has created numerous opportunities for B2B marketing professionals to enhance current marketing practices, including electronic relationships. However, the investigation of e-relationships and the factors that influence e-relationships in an internet environment is scant. Further, there appears to be no investigation of this phenomenon within the context of Greek B2B Medium-sized firms (MSF. Τhe research problem investigated in this research is: “Which drivers in B2B e-commerce use affect inter-firm relationships in medium-sized B2B firms?”. A framework for B2B e-commerce relationships in a changing and globalized environment was synthesised and integrated with the literature about relationship marketing to arrive at the following research issues: “How do relationship marketing drivers affect the management of B2B e-relationships?”. An explanatory quantitative research approach was used and quantitative data was collected from B2B firms in Greece, which represents a case of e-commerce progress during the last six years. Regarding social exchange, some important differences emerge where cooperation between B2B e-commerce firms is concerned. Suppliers engaged in electronic commerce are more committed and oriented to a long-term relationship than buyers, based on both previous and current experience with them. Confidence in the relationships, consistency and honesty with their obligations and the exchange of reliable, trustworthy information and advisory services between firms are important factors in the development and establishment of their e-relationships. The main contribution of this research is the development of a theoretical framework for e-relationships in medium-sized Β2Β firms. That framework is the first rigorously researched step towards understanding the importance of these powerful streams of relationship drivers in total, and the business activity of e-marketing and electronic relationships.

  7. Framing agenda for business model innovation research from the B2B context

    Neupane, Ganesh Prasad; Haugland, Sven A.

    2016-01-01

    This paper reviews the literature on business models in the business-to-business (B2B) context and proposes a research agenda that can be explored by future studies using various management and organizational theories. We outline four research themes and seven research topics for research on business model innovations in the B2B context. Further studies on these topics can make significant contributions to the business model literature.

  8. Dielectric and optical properties of glasses of CdO-B2O3 system

    Semin, V.N.; Mal'tsev, V.T.; Panich, A.E.

    1986-01-01

    Dielectric and optical properties of glasses of CdO-B 2 O 3 system are investigated. It is shown, that on changing the composition, cadmic-borate glasses undergo structural changes, similar to those, taking place in lead-borate glasses, and the maximum part of the boron atoms in the oxygen tetrahedral coordination is at CdO:B 2 O 3 =3:2

  9. Endothelium-dependent vasorelaxant effect of procyanidin B2 on human internal mammary artery.

    Novakovic, Aleksandra; Marinko, Marija; Jankovic, Goran; Stojanovic, Ivan; Milojevic, Predrag; Nenezic, Dragoslav; Kanjuh, Vladimir; Yang, Qin; He, Guo-Wei

    2017-07-15

    The aim of the present study was to investigate and characterize vasorelaxant effect of procyanidin B2 on human internal mammary artery (HIMA) as one of the mechanisms of its protective effect against vascular risk. Procyanidin B2 induced strong concentration-dependent relaxation of HIMA rings pre-contracted by phenylephrine. Pretreatment with L-NAME, a NO synthase inhibitor, hydroxocobalamin, a NO scavenger, and ODQ, an inhibitor of soluble guanylate cyclase, significantly inhibited procyanidin B2-induced relaxation of HIMA, while indomethacin, a cyclooxygenase inhibitor, considerably reduced effects of low concentrations. Among K + channel blockers, iberiotoxin, a selective blocker of large conductance Ca 2+ -activated K + channels (BK Ca ), abolished procyanidin B2-induced relaxation, glibenclamide, a selective ATP-sensitive K + (K ATP ) channels blocker, induced partial inhibition, while 4-aminopyridine, a blocker of voltage-gated K + (K V ) channels, and TRAM-34, an inhibitor of intermediate-conductance Ca 2+ -activated K + (IK Ca ) channels, slightly reduced maximal relaxation of HIMA. Further, procyanidin B2 relaxed contraction induced by phenylephrine in Ca 2+ -free Krebs solution, but had no effect on contraction induced by caffeine. Finally, thapsigargin, a sarcoplasmic reticulum Ca 2+ -ATPase inhibitor, significantly reduced relaxation of HIMA produced by procyanidin B2. These results demonstrate that procyanidin B2 produces endothelium-dependent relaxation of HIMA pre-contracted by phenylephrine. This effect is primarily the result of an increased NO synthesis and secretion by endothelial cells and partially of prostacyclin, although it involves activation of BK Ca and K ATP , as well as K V and IK Ca channels in high concentrations of procyanidin B2. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Prostaglandin E2 and thromboxane B2 release from human monocytes treated with bacterial lipopolysaccharide

    Nichols, F.C.; Garrison, S.W.; Davis, H.W.

    1988-01-01

    We investigated the capacity of counterflow-isolated human monocytes to independently synthesize thromboxane B2 (TxB2) and prostaglandin E2 (PGE2) when stimulated with bacterial lipopolysaccharide (LPS). Independent metabolism was confirmed by establishing different specific activities (dpm/ng) of TxB2 and PGE2 released from LPS-treated cells. For metabolites released during the initial 2-hr treatment period, the specific activity of PGE2 was approximately threefold higher than that of TxB2 regardless of labeling with [3H]arachidonic acid (AA) or [14C]AA. Cells that were pulse-labeled for 2 hr with [3H]AA demonstrated a decreasing PGE2 specific activity over 24 hr, whereas the TxB2 specific activity remained unchanged. In contrast, cells continuously exposed to [14C]AA demonstrated an increasing TxB2 specific activity that approached the level of PGE2 by 24 hr. These results suggest the presence of at least 2 cyclooxygenase metabolic compartments in counterflow-isolated monocytes. Although freshly isolated monocytes have been reported to contain variable numbers of adherent platelets, additional experiments demonstrated that counterflow-isolated platelets are not capable of releasing elevated levels of TxB2 or PGE2 when treated with LPS. It is proposed from these findings that at least two subsets of monocytes exist in peripheral blood that can be distinguished on the basis of independent conversion of AA to TxB2 and PGE2

  11. An ANFIS-based on B2C electronic commerce transaction

    Lin, Juan; Liu, Chenlian; Guo, Yongning

    2014-01-01

    The purpose of this study is to use an adaptive-network-based fuzzy inference system to model a fuzzy logic-based system (FIS) for supporting decision-making process in B2C electronic commerce transaction. Firstly we introduce FIS in B2C electronic commerce transaction and ANFIS. Then we use ANFIS to model FIS with different membership functions(MF). Lastly we give a conclusion

  12. An ANFIS-based on B2C electronic commerce transaction

    Lin, Juan, E-mail: linjuanliucaihong@qq.com [Department of Mathematics and Computer Science, Fuqing Branch of Fujian Normal University, Fuqing 350300 (China); Liu, Chenlian, E-mail: chenglian.liu@gmail.com [School of Mathematics and Computer Science, Long Yan University, Longyan 364012 (China); Guo, Yongning, E-mail: guoyn@163.com [Fuqing Branch of Fujian Normal University, Fuqing 350300 (China)

    2014-10-06

    The purpose of this study is to use an adaptive-network-based fuzzy inference system to model a fuzzy logic-based system (FIS) for supporting decision-making process in B2C electronic commerce transaction. Firstly we introduce FIS in B2C electronic commerce transaction and ANFIS. Then we use ANFIS to model FIS with different membership functions(MF). Lastly we give a conclusion.

  13. An ANFIS-based on B2C electronic commerce transaction

    Lin, Juan; Liu, Chenlian; Guo, Yongning

    2014-10-01

    The purpose of this study is to use an adaptive-network-based fuzzy inference system to model a fuzzy logic-based system (FIS) for supporting decision-making process in B2C electronic commerce transaction. Firstly we introduce FIS in B2C electronic commerce transaction and ANFIS. Then we use ANFIS to model FIS with different membership functions(MF). Lastly we give a conclusion.

  14. Structural stability of the square flux line lattice in YNi2B2C and LuNi2B2C studied with small angle neutron scattering

    Eskildsen, M.R.; Gammel, P.L.; Barber, B.P.

    1997-01-01

    We have studied the flux line lattice in YNi2B2C and LuNi2B2C, the nonmagnetic end members of the borocarbide superconductors using small angle neutron scattering and transport. For fields, H parallel to c, we find a square symmetric lattice which disorders rapidly above H/H-c2 similar to 0.2, well...... below the ''peak effect'' at H/H-c2 = 0.9. The results for H/H-c2 controlled by the tilt modulus c(44). For H/H-c2 > 0.2, the disordering appears to be associated with the field dependence of the shear modulus, C-66....

  15. Incommensurate magnetic modulations in the magnetic superconductor HoNi2B2C

    Schneider, M.; Zaharko, O.; Keller, L.; Allenspach, P.; Kreyssig, A.; Canfield, P.C.

    2006-01-01

    Full text: The borocarbide HoNi 2 B 2 C is an unconventional superconductor of particular interest, since long-range magnetism coexists and competes with superconductivity on a common energy range [1]. Our study is based on high quality single crystals of 11 B-substituted HoNi 2 B 2 C. The neutron diffraction investigations are devoted to two issues of specific relevance to HoNi 2 B 2 C. Firstly, the near re-entrant phase between 5K 2 B 2 C is more complicated than proposed so fare [2]. Furthermore we performed a spherical neutron polarimetry experiment to determine the two ICM magnetic structures of HoNi 2 B 2 C and neutron spectroscopy investigations to obtain the microscopic magnetic coupling parameters. All these studies resulted in quite a consistent and complete picture of magnetism in HoNi 2 B 2 C, however, we could not find clear evidence for a strong interaction between superconductivity and magnetism. (author)

  16. Design of MgB2 Superconducting coils for the Ignitor Experiment*

    Grasso, G.; Penco, R.; Berta, S.; Coppi, B.; Giunchi, G.

    2009-11-01

    A feasibility study for the adoption of MgB2 superconducting cables for the largest (about 5 m in diameter) of the poloidal field coils of the Ignitor machine is being carried out. This initiative was prompted by the progress made in the fabrication of MgB2 long cables, and related superconducting magnets of relatively large dimensions. These magnets will be cryocooled at the operating temperature of 10-15 K that is compatible with the He-gas cryogenic cooling system of Ignitor as well as with the projected superconducting current density of the MgB2 material, at the magnetic field values (˜4-5 T) in which these coils are designed to operate. The optimal cable configuration has been identified that can provide an efficient cooling of the MgB2 conductors over times compatible with the machine duty cycles. MgB2 superconductors hold the promise of becoming suitable for high field magnets by appropriate doping of the material and of replacing gradually the normal conducting coils adopted, by necessity, in high field experiments. Therefore, an appropriate R&D program on the development of improved MgB2 material and related superconducting cabling options has been undertaken, involving different institutions.

  17. Chimeric DNA Vaccines against ErbB2{sup +} Carcinomas: From Mice to Humans

    Quaglino, Elena; Riccardo, Federica; Macagno, Marco; Bandini, Silvio; Cojoca, Rodica; Ercole, Elisabetta [Molecular Biotechnology Center, Department of Clinical and Biological Sciences, University of Turin, 10126 Turin (Italy); Amici, Augusto [Department of Molecular Cellular and Animal Biology, University of Camerino, 62032 Camerino (Italy); Cavallo, Federica, E-mail: federica.cavallo@unito.it [2 Department of Molecular Cellular and Animal Biology, University of Camerino, 62032 Camerino (Italy)

    2011-08-10

    DNA vaccination exploits a relatively simple and flexible technique to generate an immune response against microbial and tumor-associated antigens (TAAs). Its effectiveness is enhanced by the application of an electrical shock in the area of plasmid injection (electroporation). In our studies we exploited a sophisticated electroporation device approved for clinical use (Cliniporator, IGEA, Carpi, Italy). As the target antigen is an additional factor that dramatically modulates the efficacy of a vaccine, we selected ErbB2 receptor as a target since it is an ideal oncoantigen. It is overexpressed on the cell membrane by several carcinomas for which it plays an essential role in driving their progression. Most oncoantigens are self-tolerated molecules. To circumvent immune tolerance we generated two plasmids (RHuT and HuRT) coding for chimeric rat/human ErbB2 proteins. Their immunogenicity was compared in wild type mice naturally tolerant for mouse ErbB2, and in transgenic mice that are also tolerant for rat or human ErbB2. In several of these mice, RHuT and HuRT elicited a stronger anti-tumor response than plasmids coding for fully human or fully rat ErbB2. The ability of heterologous moiety to blunt immune tolerance could be exploited to elicit a significant immune response in patients. A clinical trial to delay the recurrence of ErbB2{sup +} carcinomas of the oral cavity, oropharynx and hypopharynx is awaiting the approval of the Italian authorities.

  18. Flux pinning behaviors of Ti and C co-doped MgB2 superconductors

    Yang, Y.; Zhao, D.; Shen, T.M.; Li, G.; Zhang, Y.; Feng, Y.; Cheng, C.H.; Zhang, Y.P.; Zhao, Y.

    2008-01-01

    Flux pinning behavior of carbon and titanium concurrently doped MgB 2 alloys has been studied by ac susceptibility and dc magnetization measurements. It is found that critical current density and irreversibility field of MgB 2 have been significantly improved by doping C and Ti concurrently, sharply contrasted to the situation of C-only-doped or Ti-only-doped MgB 2 samples. AC susceptibility measurement reveals that the dependence of the pinning potential on the dc applied field of Mg 0.95 Ti 0.05 B 1.95 C 0.05 has been determined to be U(B dc )∝B dc -1 compared to that of MgB 2 U(B dc )∝B dc -1.5 . As to the U(J) behavior, a relationship of U(J) ∝ J -0.17 is found fitting well for Mg 0.95 Ti 0.05 B 1.95 C 0.05 with respect to U(J) ∝ J -0.21 for MgB 2 . All the results reveal a strong enhancement of the high field pinning potential in C and Ti co-doped MgB 2

  19. Phase transformations in the B2 phase of Co-rich Co-Al binary alloys

    Niitsu, K.; Omori, T.; Nagasako, M.; Oikawa, K.; Kainuma, R.; Ishida, K.

    2011-01-01

    Research highlights: → Bainitic transformation and a martensite-like structure from B2-CoAl were observed depending on quenching rate. → The phase separation into the metastable A2 + B2 structure was found in the as-quenched B2-CoAl. → The two-phase structure of A2 and B2 was found to show some coercive force after aging under a magnetic field. - Abstract: Phase transformations in the β (B2) phase of Co-21 and -23 at.% Al alloys were examined using transmission electron microscopy, energy dispersive X-ray spectroscopy and differential scanning calorimetry. The microstructures obtained from as-quenched specimens were found to be strongly affected by the quenching condition. While relatively thick sheet-specimens with a lower quenching rate showed bainitic plate precipitates with a fcc structure, a martensite-like structure was observed by optical microscopy in relatively thin specimens with a higher quenching rate. Regardless of the quenching condition, a spinodal-like microstructure composed of A2 and B2 phases was also detected and the A2 phase changed to a metastable hcp phase during further aging.

  20. Critical state instability in Nb-clad MgB2 superconducting wires

    Beilin, V.; Felner, I.; Tsindlekht, M.I.; Dul'kin, E.; Mojaev, E.; Roth, M.

    2008-01-01

    Magnetization hysteresis loops of Cu/MgB 2 , Nb/MgB 2 , Cu/Nb/MgB 2 and Fe/Cu/MgB 2 wires in parallel magnetic fields of up to 5 T were studied in the temperature range from 5 to 35 K. All Nb-clad samples exhibited a thermomagnetic instability (TMI) in the form of magnetization jumps. In a thick wire (about 2 mm in core diameter), the TMI persisted up to the unexpectedly high temperature of 32 K. Thin wires showed low TMI which vanished at T > 10 K. Cu/MgB 2 wires which did not contain a Nb barrier, showed no signs of TMI. The TMI in thin wires exhibited good reproducibility and stability in the jump pattern (JP) (jump amplitudes and positions), while thick wires showed the worst time stability. We found that moderate flat rolling of the round unstable Cu/Nb/MgB 2 wire resulted in negligible TMI at 5 K in the processed flat tape. The TMI amplitudes of studied samples correlated with the adiabatic stability parameter, β -1

  1. Preferential control of basal dendritic protrusions by EphB2.

    Matthew S Kayser

    2011-02-01

    Full Text Available The flow of information between neurons in many neural circuits is controlled by a highly specialized site of cell-cell contact known as a synapse. A number of molecules have been identified that are involved in central nervous system synapse development, but knowledge is limited regarding whether these cues direct organization of specific synapse types or on particular regions of individual neurons. Glutamate is the primary excitatory neurotransmitter in the brain, and the majority of glutamatergic synapses occur on mushroom-shaped protrusions called dendritic spines. Changes in the morphology of these structures are associated with long-lasting modulation of synaptic strength thought to underlie learning and memory, and can be abnormal in neuropsychiatric disease. Here, we use rat cortical slice cultures to examine how a previously-described synaptogenic molecule, the EphB2 receptor tyrosine kinase, regulates dendritic protrusion morphology in specific regions of the dendritic arbor in cortical pyramidal neurons. We find that alterations in EphB2 signaling can bidirectionally control protrusion length, and knockdown of EphB2 expression levels reduces the number of dendritic spines and filopodia. Expression of wild-type or dominant negative EphB2 reveals that EphB2 preferentially regulates dendritic protrusion structure in basal dendrites. Our findings suggest that EphB2 may act to specify synapse formation in a particular subcellular region of cortical pyramidal neurons.

  2. Development of Ti-sheathed MgB2 wires with high critical current density

    Liang, G; Fang, H; Hanna, M; Yen, F; Lv, B; Alessandrini, M; Keith, S; Hoyt, C; Tang, Z; Salama, K

    2006-01-01

    Working towards developing lightweight superconducting magnets for future space and other applications, we have successfully fabricated mono-core Ti-sheathed MgB 2 wires by the powder-in-tube method. The wires were characterized by magnetization, electrical resistivity, x-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry measurements. The results indicate that the Ti sheath does not react with the magnesium and boron, and the present wire rolling process can produce MgB 2 wires with a superconducting volume fraction of at least 64% in the core. Using the Bean model, it was found that at 5 K, the magnetic critical current densities, J c , measured in magnetic fields of 0, 5, and 8 T are about 4.2 x 10 5 , 3.6 x 10 4 , and 1.4 x 10 4 A cm -2 , respectively. At 20 K and 0 T, the magnetic J c is about 2.4 x 10 5 A cm -2 . These results show that at zero and low fields, the values of the magnetic J c for Ti-sheathed MgB 2 wires are comparable with the best results available for the Fe-sheathed MgB 2 wires. At high fields, however, the J c for Ti-sheathed MgB 2 wires appears higher than that for the Fe-sheathed MgB 2 wires

  3. Preparation, characterization, and thermal stability of B2O3-ZrO2

    Theresia Debora Simbolon

    2017-04-01

    Full Text Available Synthesis of the borate-based compound with ZrOCl2 to form B2O3-ZrO2 has been conducted. The compound was characterized by FT-IR spectrophotometer, X-ray diffraction, acidity and thermal stability test. The results showed that the FT-IR main vibration spectrum of B2O3-ZrO2 compound has appeared at wave number 401.2 cm-1 for Zr-O bonding vibration, 617.2 cm-1 for B-O-B bonding vibration and 910.4 cm-1 for B-O bonding vibration. The XRD diffraction pattern shows B2O3-ZrO2 compound has an amorphous structure. The FT-IR spectrum after saturated with ammonia and potentiometric titration indicates that the compound of B2O3-ZrO2 has acidic properties with a strong level of acidity. Thermal stability test shows that the B2O3-ZrO2 compounds have high stability on temperature with increasing crystallinity after the compound was heated at 700 °C. Keywords: B2O3-ZrO2, impregnation, thermal stability.

  4. Occurrence of Ochratoxins, Fumonisin B2 , Aflatoxins (B1 and B2 ), and Other Secondary Fungal Metabolites in Dried Date Palm Fruits from Egypt: A Mini-Survey.

    Abdallah, Mohamed F; Krska, Rudolf; Sulyok, Michael

    2018-02-01

    This study was conducted to investigate the natural co-occurrence of 295 fungal and bacterial metabolites in 28 samples of dried date palm fruits collected from different shops distributed in Assiut Governorate, Upper Egypt in 2016. Extraction and quantification of the target analytes were done using the "dilute and shoot" approach followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. In total, 30 toxic fungal metabolites were detected. Among these metabolites, 4 types of ochratoxins including ochratoxin type A and B were quantified in 3 samples (11%) with a contamination range from 1.48 to 6070 μg/kg for ochratoxin A and from 0.28 to 692 μg/kg for ochratoxin B. In addition, fumonisin B 2 was observed in 2 (7%) samples with contamination levels ranging from 4.99 to 16.2 μg/kg. The simultaneous detection of fumonisin B 2 in the same contaminated samples with ochratoxins indicates the fungal attack by Aspergillus niger species during storage. Only 1 sample was contaminated with aflatoxin B 1 (14.4 μg/kg) and B 2 (2.44 μg/kg). The highest maximum concentration (90400 μg/kg) was for kojic acid that contaminated 43% of the samples. To the best of the authors' knowledge, this is the first report of the natural co-occurrence of fumonisin B 2 and ochratoxin A and B in addition to a wide range of other fungal metabolites in date palm fruits. Mycotoxins are secondary metabolites produced by different fungi. These metabolites pose a potential risk on human health since they contaminate many food commodities. Among these, date palm fruits which are an integral part of diet in several countries. Therefore, detection of mycotoxins is a prerequisite to insure the safety of food. Here, different types of mycotoxins have been detected in levels that may have health hazard. © 2018 Institute of Food Technologists®.

  5. The Power of B2B Brands : A case study of how B2B companies in the forest industry can communicate sustainability through their Brand

    Bålfors, Joakim; Ståhlspets, Johan

    2016-01-01

    Today’s B2B companies operate in a global business world that is characterised by product homogenisation and intense competition. Finding sources for differentiation and consequently competitive advantage is a concern that no company with a long-term horizon can ignore. The development of the brand, recognized as a strategic asset, has created new ways of conducting beneficial marketing management, which can lead to differentiation from competitors and create conditions for company success. T...

  6. Solution structure of the human Grb7-SH2 domain/erbB2 peptide complex and structural basis for Grb7 binding to ErbB2

    Ivancic, Monika; Daly, Roger J.; Lyons, Barbara A.

    2003-01-01

    The solution structure of the hGrb7-SH2 domain in complex with a ten amino acid phosphorylated peptide ligand representative of the erbB2 receptor tyrosine kinase (pY1139) is presented as determined by nuclear magnetic resonance methods. The hGrb7-SH2 domain structure reveals the Src homology 2 domain topology consisting of a central β-sheet capped at each end by an α-helix. The presence of a four residue insertion in the region between β-strand E and the EF loop and resulting influences on the SH2 domain/peptide complex structure are discussed. The binding conformation of the erbB2 peptide is in a β-turn similar to that found in phosphorylated tyrosine peptides bound to the Grb2-SH2 domain. To our knowledge this is only the second example of an SH2 domain binding its naturally occurring ligands in a turn, instead of extended, conformation. Close contacts between residues responsible for binding specificity in hGrb7-SH2 and the erbB2 peptide are characterized and the potential effect of mutation of these residues on the hGrb7-SH2 domain structure is discussed

  7. Competency-orientated brand cooperations of power supply companies in the B2B sector; Kompetenzorientierte Markenkooperationen von Energieversorgungsunternehmen im B2B-Kundenbereich

    Peuser, M.M.

    2008-07-01

    On the basis of an extensive empirical study with B2B electricity users, the author of the book under consideration examines brand co-operations of power supply companies with companies not working in the area of energy production. Based on the view of various co-operation alternatives, impact relations and success-determining factors of influence in the area of B2B customers are identified. The term of the authority of an energy brand is discussed. Beside this, profiles of concrete brands of current power supply companies from the view of B2B customers are pointed out, and recommendations for the organization of brand co-operation and the structure of mark authority in practice are shown. This contribution is written for lecturers and students of the management economics with the emphasis of marketing and management as well as high-level personnel in the energy industry, who wants to develop strong mark authority by brand co-operation.

  8. Nuclear reactors

    Prescott, R.F.

    1976-01-01

    A nuclear reactor containment vessel faced internally with a metal liner is provided with thermal insulation for the liner, comprising one or more layers of compressible material such as ceramic fiber, such as would be conventional in an advanced gas-cooled reactor and also a superposed layer of ceramic bricks or tiles in combination with retention means therefor, the retention means (comprising studs projecting from the liner, and bolts or nuts in threaded engagement with the studs) being themselves insulated from the vessel interior so that the coolant temperatures achieved in a High-Temperature Reactor or a Fast Reactor can be tolerated with the vessel. The layer(s) of compressible material is held under a degree of compression either by the ceramic bricks or tiles themselves or by cover plates held on the studs, in which case the bricks or tiles are preferably bedded on a yielding layer (for example of carbon fibers) rather than directly on the cover plates

  9. Nuclear reactor

    Miyashita, Akio.

    1981-01-01

    Purpose: To facilitate and accelerate a leakage test of valves of a main steam pipe by adding a leakage test partition valve thereto. Constitution: A leakage testing partition valve is provided between a pressure vessel for a nuclear reactor and the most upstream side valve of a plurality of valves to be tested for leakage, a testing branch pipe is communicated with the downstream side of the partition valve, and the testing water for preventing leakage is introduced thereto through the branch pipe. Since main steam pipe can be simply isolated by closing the partition valve in the leakage test, the leakage test can be conducted without raising or lowering the water level in the pressure vessel, and since interference with other work in the reactor can be eliminated, the leakage test can be readily conducted parallel with other work in the reactor in a short time. Clean water can be used without using reactor water as the test water. (Yoshihara, H.)

  10. Reactor container

    Abe, Yoshihito; Sano, Tamotsu; Ueda, Sabuo; Tanaka, Kazuhisa.

    1987-01-01

    Purpose: To improve the liquid surface disturbance in LMFBR type reactors. Constitution: A horizontal flow suppressing mechanism mainly comprising vertical members is suspended near the free liquid surface of coolants in the upper plenum. The horizontal flow of coolants near the free liquid surface is reduced by the suppressing mechanism to effectively reduce the surface disturbance. The reduction in the liquid surface disturbance further prevails to the entire surface region with no particular vertical variations to the free liquid surface to remarkably improve the preventive performance for the liquid surface disturbance. Accordingly, it is also possible to attain the advantageous effects such as prevention for the thermal fatigue in reactor vessel walls, reactor upper mechanisms, etc. and prevention of burning damage to the reactor core due to the reduction of envolved Ar gas. (Kamimura, M.)

  11. REACTOR SHIELD

    Wigner, E.P.; Ohlinger, L.E.; Young, G.J.; Weinberg, A.M.

    1959-02-17

    Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

  12. NUCLEAR REACTOR

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  13. Breeder reactors

    Gollion, H.

    1977-01-01

    The reasons for the development of fast reactors are briefly reviewed (a propitious neutron balance oriented towards a maximum uranium burnup) and its special requirements (cooling, fissile material density and reprocessing) discussed. The three stages in the French program of fast reactor development are outlined with Rapsodie at Cadarache, Phenix at Marcoule, and Super Phenix at Creys-Malville. The more specific features of the program of research and development are emphasized: kinetics and the core, the fuel and the components [fr

  14. Nuclear reactor

    Schulze, I.; Gutscher, E.

    1980-01-01

    The core contains a critical mass of UN or U 2 N 3 in the form of a noncritical solution with melted Sn being kept below a N atmosphere. The lining of the reactor core consists of graphite. If fission progresses part of the melted metal solution is removed and cleaned from fission products. The reactor temperatures lie in the range of 300 to 2000 0 C. (Examples and tables). (RW) [de

  15. Reactor technology

    Erdoes, P.

    1977-01-01

    This is one of a series of articles discussing aspects of nuclear engineering ranging from a survey of various reactor types for static and mobile use to mention of atomic thermo-electric batteries of atomic thermo-electric batteries for cardiac pacemakers. Various statistics are presented on power generation in Europe and U.S.A. and economics are discussed in some detail. Molten salt reactors and research machines are also described. (G.M.E.)

  16. Reactor containment

    Kawabe, Ryuhei; Yamaki, Rika.

    1990-01-01

    A water vessel is disposed and the gas phase portion of the water vessel is connected to a reactor container by a pipeline having a valve disposed at the midway thereof. A pipe in communication with external air is extended upwardly from the liquid phase portion to a considerable height so as to resist against the back pressure by a waterhead in the pipeline. Accordingly, when the pressure in the container is reduced to a negative level, air passes through the pipeline and uprises through the liquid phase portion in the water vessel in the form of bubbles and then flows into the reactor container. When the pressure inside of the reactor goes higher, since the liquid surface in the water vessel is forced down, water is pushed up into the pipeline. Since the waterhead pressure of a column of water in the pipeline and the pressure of the reactor container are well-balanced, gases in the reactor container are not leaked to the outside. Further, in a case if a great positive pressure is formed in the reactor container, the inner pressure overcomes the waterhead of the column of water, so that the gases containing radioactive aerosol uprise in the pipeline. Since water and the gases flow being in contact with each other, this can provide the effect of removing aerosol. (T.M.)

  17. Fast reactors

    Vasile, A.

    2001-01-01

    Fast reactors have capacities to spare uranium natural resources by their breeding property and to propose solutions to the management of radioactive wastes by limiting the inventory of heavy nuclei. This article highlights the role that fast reactors could play for reducing the radiotoxicity of wastes. The conversion of 238 U into 239 Pu by neutron capture is more efficient in fast reactors than in light water reactors. In fast reactors multi-recycling of U + Pu leads to fissioning up to 95% of the initial fuel ( 238 U + 235 U). 2 strategies have been studied to burn actinides: - the multi-recycling of heavy nuclei is made inside the fuel element (homogeneous option); - the unique recycling is made in special irradiation targets placed inside the core or at its surroundings (heterogeneous option). Simulations have shown that, for the same amount of energy produced (400 TWhe), the mass of transuranium elements (Pu + Np + Am + Cm) sent to waste disposal is 60,9 Kg in the homogeneous option and 204.4 Kg in the heterogeneous option. Experimental programs are carried out in Phenix and BOR60 reactors in order to study the feasibility of such strategies. (A.C.)

  18. The French nuclear power plant reactor building containment contributions of prestressing and concrete performances in reliability improvements and cost savings

    Rouelle, P.; Roy, F.

    1998-01-01

    The Electricite de France's N4 CHOOZ B nuclear power plant, two units of the world's largest PWR model (1450 Mwe each), has earned the Electric Power International's 1997 Powerplant Award. This lead NPP for EDF's N4 series has been improved notably in terms of civil works. The presentation will focus on the Reactor Building's inner containment wall which is one of the main civil structures on a technical and safety point of view. In order to take into account the necessary evolution of the concrete technical specification such as compressive strength low creep and shrinkage, the HSC/HPC has been used on the last N4 Civaux 2 NPP. As a result of the use of this type of professional concrete, the containment withstands an higher internal pressure related to severe accident and ensures higher level of leak-tightness, thus improving the overall safety of the NPP. On that occasion, a new type of prestressing has been tested locally through 55 C 15 S tendons using a new C 1500 FE Jack. These updated civil works techniques shall allow EDF to ensure a Reactor Containment lifespan for more than 50 years. The gains in terms of reliability and cost saving of these improved techniques will be developed hereafter

  19. Possible multigap type-I superconductivity in the layered boride RuB2

    Singh, Jaskaran; Jayaraj, Anooja; Srivastava, D.; Gayen, S.; Thamizhavel, A.; Singh, Yogesh

    2018-02-01

    The structure of the layered transition-metal borides A B2 (A =Os,Ru ) is built up by alternating T and B layers with the B layers forming a puckered honeycomb. Here we report superconducting properties of RuB2 with a Tc≈1.5 K using measurements of the magnetic susceptibility versus temperature T , magnetization M versus magnetic field H , resistivity versus T , and heat capacity versus T at various H . We observe a reduced heat capacity anomaly at Tc given by Δ C /γ Tc≈1.1 suggesting multigap superconductivity. Strong support for this is obtained by the successful fitting of the electronic specific heat data to a two-gap model with gap values Δ1/kBTc≈1.88 and Δ2/kBTc≈1.13 . Additionally, M versus H measurements reveal a behavior consistent with type-I superconductivity. This is confirmed by comparing the experimental critical field ≈122 Oe obtained from extrapolation to T =0 of the H -T phase diagram, with an estimate of the T =0 thermodynamic critical field ≈114 Oe. Additionally, the Ginzburg-Landau parameter was estimated to be κ ≈0.1 -0.66 . These results strongly suggest multigap type-I superconductivity in RuB2. We also calculate the band structure and obtain the Fermi surface for RuB2. The Fermi surface consists of one quasi-two-dimensional sheet and two concentric ellipsoidal sheets very similar to OsB2. An additional small fourth sheet is also found for RuB2. RuB2 could thus be an example of a multigap type-I superconductor.

  20. Grain growth kinetics for B2O3-doped ZnO ceramics

    Yuksel Berat

    2015-06-01

    Full Text Available Grain growth kinetics in 0.1 to 2 mol % B2O3-added ZnO ceramics was studied by using a simplified phenomenological grain growth kinetics equation Gn = K0 · t · exp(-Q/RT together with the physical properties of sintered samples. The samples, prepared by conventional ceramics processing techniques, were sintered at temperatures between 1050 to 1250 °C for 1, 2, 3, 5 and 10 hours in air. The kinetic grain growth exponent value (n and the activation energy for the grain growth of the 0.1 mol % B2O3-doped ZnO ceramics were found to be 2.8 and 332 kJ/mol, respectively. By increasing B2O3 content to 1 mol %, the grain growth exponent value (n and the activation energy decreased to 2 and 238 kJ/mol, respectively. The XRD study revealed the presence of a second phase, Zn3B2O6 formed when the B2O3 content was > 1 mol %. The formation of Zn3B2O6 phase gave rise to an increase of the grain growth kinetic exponent and the grain growth activation energy. The kinetic grain growth exponent value (n and the activation energy for the grain growth of the 2 mol % B2O3-doped ZnO ceramics were found to be 3 and 307 kJ/mol, respectively. This can be attributed to the second particle drag (pinning mechanism in the liquid phase sintering.

  1. Superconducting and normal-state properties of the layered boride OsB2

    Singh, Yogesh; Niazi, A.; Vannette, M. D.; Prozorov, R.; Johnston, D. C.

    2007-12-01

    OsB2 crystallizes in an orthorhombic structure (Pmmn) which contains alternate boron and osmium layers stacked along the c axis. The boron layers consist of puckered hexagons as opposed to the flat graphite-like boron layers in MgB2 . OsB2 is reported to become superconducting below 2.1K . We report results of the dynamic and static magnetic susceptibilities, electrical resistivity, Hall effect, heat capacity, and penetration depth measurements on arc-melted polycrystalline samples of OsB2 to characterize its superconducting and normal-state properties. These measurements confirmed that OsB2 becomes a bulk superconductor below Tc=2.1K . Our results indicate that OsB2 is a moderate-coupling type-II superconductor with an electron-phonon coupling constant λep≈0.4-0.5 , a small Ginzburg-Landau parameter κ˜1-2 , and an upper critical magnetic field Hc2(0.5K)˜420Oe for an unannealed sample and Hc2(1K)˜330Oe for an annealed sample. The temperature dependence of the superfluid density ns(T) for the unannealed sample is consistent with an s -wave superconductor with a slightly enhanced zero temperature gap Δ(0)=1.9kBTc and a zero temperature London penetration depth λ(0)=0.38(2)μm . The ns(T) data for the annealed sample show deviations from the predictions of the single-band s -wave BCS model. The magnetic, transport, and thermal properties in the normal state of isostructural and isoelectronic RuB2 , which is reported to become superconducting below 1.6K , are also reported.

  2. Generation IV reactors: reactor concepts

    Cardonnier, J.L.; Dumaz, P.; Antoni, O.; Arnoux, P.; Bergeron, A.; Renault, C.; Rimpault, G.; Delpech, M.; Garnier, J.C.; Anzieu, P.; Francois, G.; Lecomte, M.

    2003-01-01

    Liquid metal reactor concept looks promising because of its hard neutron spectrum. Sodium reactors benefit a large feedback experience in Japan and in France. Lead reactors have serious assets concerning safety but they require a great effort in technological research to overcome the corrosion issue and they lack a leader country to develop this innovative technology. In molten salt reactor concept, salt is both the nuclear fuel and the coolant fluid. The high exit temperature of the primary salt (700 Celsius degrees) allows a high energy efficiency (44%). Furthermore molten salts have interesting specificities concerning the transmutation of actinides: they are almost insensitive to irradiation damage, some salts can dissolve large quantities of actinides and they are compatible with most reprocessing processes based on pyro-chemistry. Supercritical water reactor concept is based on operating temperature and pressure conditions that infers water to be beyond its critical point. In this range water gets some useful characteristics: - boiling crisis is no more possible because liquid and vapour phase can not coexist, - a high heat transfer coefficient due to the low thermal conductivity of supercritical water, and - a high global energy efficiency due to the high temperature of water. Gas-cooled fast reactors combining hard neutron spectrum and closed fuel cycle open the way to a high valorization of natural uranium while minimizing ultimate radioactive wastes and proliferation risks. Very high temperature gas-cooled reactor concept is developed in the prospect of producing hydrogen from no-fossil fuels in large scale. This use implies a reactor producing helium over 1000 Celsius degrees. (A.C.)

  3. Studies of neutrino properties at nuclear reactors. Present status and future

    Mikaehlyan, L A

    2002-01-01

    The state and prospects of the experiments at nuclear reactors on the search for the neutrino mass, mixing and magnetic moments, identification whereof would prove the existence of events behind the standard model limits, are considered. The CHOOZ experiment established with complete determination, that the nu sub e -> nu sub x channel is not predominant in the atmospheric neutrino oscillations. The KamLAND may become the first among the experiments with the neutrino earth sources, wherein the oscillation effect will be determined; the contributions of the m sub 1 and m sub 2 masses to the electron neutrino is established and solution of the solar neutrino problem is found. The Kr2Det experiment with its high sensitivity to the small mixing angles may identify the contribution of the m sub 3 mass to the nu sub e or establish a new more exact limit on its value. These studies rest upon the unprecedented improvement of the reverse beta-decay registration methods

  4. Research reactors - an overview

    West, C.D.

    1997-01-01

    A broad overview of different types of research and type reactors is provided in this paper. Reactor designs and operating conditions are briefly described for four reactors. The reactor types described include swimming pool reactors, the High Flux Isotope Reactor, the Mark I TRIGA reactor, and the Advanced Neutron Source reactor. Emphasis in the descriptions is placed on safety-related features of the reactors. 7 refs., 7 figs., 2 tabs

  5. Enhancing the superconducting temperature of MgB2 by SWCNT dilution

    Ma, Danhao; Jayasingha, Ruwantha; Hess, Dustin T.; Adu, Kofi W.; Sumanasekera, Gamini U.; Terrones, Mauricio

    2014-02-01

    We report, for the first time, an increase in the superconducting critical temperature, TC of commercial “dirty” MgB2 by a nonsubstitutional hole-doping of the MgB2 structure using minute, single-wall carbon nanotube (SWCNT) inclusions. We varied the SWCNTs concentration from 0.05 wt% to 5 wt% and investigated the temperature-dependent resistivity from 10 K to 300 K. We used micro-Raman spectroscopy, field-emission scanning electron microscopy, and X-ray diffraction to analyze the interfacial interactions between the SWCNTs and the MgB2 grains. We obtained an increase in TC from 33.0 to 37.8 K (ΔTC+=4.8 K), which is attributed to charge transfer from the MgB2 structure to the SWCNT structure. The charge transfer phenomenon is confirmed by micro-Raman analysis of the phonon states of the SWCNT tangential band frequency in the composites. We determined the charge transfer per carbon atom to be 0.0023/C, 0.0018/C and 0.0008/C for 0.05 wt%, 0.5 wt% and 5 wt% SWCNT inclusions, respectively, taking into account the contributions from the softening of the lattice constant and the nonadiabatic (dynamic) effects at the Fermi level. This report provides an experimental, alternative pathway to hole-doping of MgB2 without appealing to chemical substitution.

  6. MgB_{2} nonlinear properties investigated under localized high rf magnetic field excitation

    Tamin Tai

    2012-12-01

    Full Text Available The high transition temperature and low surface resistance of MgB_{2} attracts interest in its potential application in superconducting radio frequency accelerating cavities. However, compared to traditional Nb cavities, the viability of MgB_{2} at high rf fields is still open to question. Our approach is to study the nonlinear electrodynamics of the material under localized rf magnetic fields. Because of the presence of the small superconducting gap in the π band, the nonlinear response of MgB_{2} at low temperature is potentially complicated compared to a single-gap s-wave superconductor such as Nb. Understanding the mechanisms of nonlinearity coming from the two-band structure of MgB_{2}, as well as extrinsic sources of nonlinearity, is an urgent requirement. A localized and strong rf magnetic field, created by a magnetic write head, is integrated into our nonlinear-Meissner-effect scanning microwave microscope [T. Tai et al., IEEE Trans. Appl. Supercond. 21, 2615 (2011ITASE91051-822310.1109/TASC.2010.2096531]. MgB_{2} films with thickness 50 nm, fabricated by a hybrid physical-chemical vapor deposition technique on dielectric substrates, are measured at a fixed location and show a strongly temperature-dependent third harmonic response. We propose that several possible mechanisms are responsible for this nonlinear response.

  7. Expression of oncogen c-erbB-2 (neu/HER-2) in human breast cancer

    Michelin, Severino C.; Mayo, Jose

    2000-01-01

    Breast cancer continues to be one of the leading causes of death from cancer among women and represents the most serious challenge to therapeutic control. Amplification and overexpression of the c-erbB-2 proto-oncogene occurs in as many as 30 % of all breast cancers and has been correlated with lymph node metastasis and poor prognosis in breast cancer patients. This gene know as neu, HER-2 or c-erbB-2 in among those most frequently altered in human cancer. It was first identified as a transforming gene activated in chemically induced rat neuroectodermal tumors. Early critical studies linked changes in erbB-2 expression and gene copy number to several human cancer, notably breast, ovarian and gastric cancer. Owing to its accessible location at the cell surface, erbB-2 is now under intensive scrutiny as a therapeutic target. In this review we will summarize the involvement of the c-erbB-2 gene in tumorigenesis. (author)

  8. Evaluations of MgB2 Coatings on 2'' Copper Discs for Superconducting Radio Frequency Applications

    Withanage, Wenura; Tan, Teng; Lee, Namhoon; Banjade, Huta; Eremeev, Grigory; Welander, Paul; Valente-Feliciano, Anne-Marie; Kustom, Robert; Wolak, Matthäus; Nassiri, Alireza; Xi, Xiaoxing

    We propose that coating the inner walls of copper RF cavities with superconducting MgB2 (Tc = 39 K) can result in a viable alternative to the already established niobium-based SRF technology. This approach improves the thermal conductivity, allows for operation at higher temperatures, and reduces the need for large helium refrigeration, thereby resulting in lower operational costs. For our studies, we grew MgB2 films via hybrid physical chemical vapor deposition (HPCVD) on 2'' Cu substrates. Since Mg and Cu readily form an alloy at higher temperatures, the HPCVD setup was modified in order to achieve lower deposition temperatures, minimize alloy formation, and provide high quality MgB2 films. This method yielded MgB2 coatings on 2'' Cu discs with transition temperatures around 38 K. The samples were characterized with regards to their RF attributes and showed similar performance in comparison to Nb reference samples. The presented results show that MgB2 coated copper can be a suitable alternative for use in SRF cavities.

  9. Pressure induced structural phase transition of OsB2: First-principles calculations

    Ren Fengzhu; Wang Yuanxu; Lo, V.C.

    2010-01-01

    Orthorhombic OsB 2 was synthesized at 1000 deg. C and its compressibility was measured by using the high-pressure X-ray diffraction in a Diacell diamond anvil cell from ambient pressure to 32 GPa [R.W. Cumberland, et al. (2005)]. First-principles calculations were performed to study the possibility of the phase transition of OsB 2 . An analysis of the calculated enthalpy shows that orthorhombic OsB 2 can transfer to the hexagonal phase at 10.8 GPa. The calculated results with the quasi-harmonic approximation indicate that this phase transition pressure is little affected by the thermal effect. The calculated phonon band structure shows that the hexagonal P 6 3 /mmc structure (high-pressure phase) is stable for OsB 2 . We expect the phase transition can be further confirmed by the experimental work. - Abstract: Graphical Abstract Legend (TOC Figure): Table of Contents Figure Pressure induced structural phase transition from the orthorhombic structure to the hexagonal one for OsB 2 takes place under 10.8 GPa (0 K), 10.35 GPa (300, 1000 K) by the first-principles predictions.

  10. Energy gap in MgB2 superconductor: Andreev reflection studies

    Aswal, D.K.

    2003-01-01

    To investigate the nature of energy gap in MgB 2 superconductor, we have performed Andreev-reflection studies on MgB 2 / Ag planar junctions. The differential resistance (dV/dI) versus voltage (V) characteristics were recorded as a function of temperature, magnetic field and junction-type. The dV/dI vs V characteristic recorded at low temperature and zero-field for a clean MgB 2 / Ag planar junction exhibited several interesting features, such as, zero bias anomaly, a distinct double-minima, sharp resonance peaks near the energy gap etc. The data, however, could not be explained using Blonder-Tinkham-Klapwijk theory of isotropic superconductor, which indicated that energy gap in MgB 2 is not consistent with the weak-coupling BCS theory. This is further supported by unusual temperature and magnetic field dependence of the tunneling characteristics. The results indicate several possibilities for the energy gap in MgB 2 , such as, an anisotropic energy gap, two-energy or an unconventional gap scenario. (author)

  11. Design of MgB2 superconducting dipole magnet for particle beam transport in accelerators

    Abrahamsen, A.B.; Zangenberg, N.; Baurichter, A.

    2006-01-01

    for the collaborating company Danfysik A/S, which has a strongtradition in building resistive magnets for particle accelerators[4]. A technology transfer project was formulated at the end of 2005 with the purpose to collect the knowledge about the MgB2 superconductor gained in the STVF program and in the European...... in a dipole magnet for guiding particle beams in a small scale accelerator is examined with the purpose to build lighter and smaller than the present resistive magnets. Here the criticalcurrent density of primarily MgB2 will be compared with current density determined by specifications similar to the Tevatron...... accelerator, B = 4:4 Tesla and coil aperture D = 76 mm [6], which has been identified by Danfysik A/S as interesting. It isconcluded that MgB2 is useful for the dipole application and construction of a small test coil of one half of the magnet is planned in 2007....

  12. Microstructure and pinning properties of hexagonal-disc shaped single crystalline MgB2

    Jung, C. U.; Kim, J. Y.; Chowdhury, P.; Kim, Kijoon H.; Lee, Sung-Ik; Koh, D. S.; Tamura, N.; Caldwell, W. A.; Patel, J. R.

    2002-11-01

    We synthesized hexagonal-disc-shaped MgB2 single crystals under high-pressure conditions and analyzed the microstructure and pinning properties. The lattice constants and the Laue pattern of the crystals from x-ray micro-diffraction showed the crystal symmetry of MgB2. A thorough crystallographic mapping within a single crystal showed that the edge and c axis of hexagonal-disc shape exactly matched the [101¯0] and the [0001] directions of the MgB2 phase. Thus, these well-shaped single crystals may be the best candidates for studying the direction dependences of the physical properties. The magnetization curve and the magnetic hysteresis curve for these single crystals showed the existence of a wide reversible region and weak pinning properties, which supported our single crystals being very clean.

  13. Composition powders of the system TiC-TiB2

    Degrave, I.E.; Udalov, Yu.P.

    2000-01-01

    The ceramic composition on TiC-TiB 2 base is proposed for substitution of scarce and expensive tungsten carbide for manufacturing metallo-ceramic articles. The technology of TiC and TiB 2 powder production from the mixture of oxides and carbon-bearing reducing agents is developed. Saccharose is recommended to be used as a reductant. Carbon tetrachloride vapors are introduced into the reaction volume to accelerate the synthesis. The purification of the product from residual carbon is performed in high frequency glow discharge with the use of air as a plasma forming gas. Microstructural studies show that the product obtained constitutes submicron TiC particles in a TiB 2 matrix [ru

  14. Possible superlattice formation in high-temperature treated carbonaceous MgB2 at elevated pressure

    Tschauner, Oliver; Errandonea, Daniel; Serghiou, George

    2006-01-01

    We report indications of a phase transition in carbonaceous MgB 2 above 9 GPa at 300 K after stress relaxation by laser heating. The transition was detected using Raman spectroscopy and X-ray diffraction. The observed changes are consistent with a second-order structural transition involving a doubling of the unit cell along c and a reduction of the boron site symmetry. Moreover, the Raman spectra suggest a reduction in electron-phonon coupling in the slightly modified MgB 2 structure consistent with the previously proposed topological transition in MgB 2 . However, further attributes including deviatoric stress, lattice defects, and compositional variation may play an important role in the observed phenomena

  15. Vitamin B2 content determination in liver paste by using acid and acid-enzyme hydrolysis

    Basić Zorica

    2007-01-01

    Full Text Available Background/Aim. Vitamin B2 is available in foodstuff in the form of coenzyme and in free form. For its content determination a few procedures should be performed (deliberation from a complex, extraction of free and deliberated form and detection, identification and quantification. There is a particular problem in determination of vitamin B2 in the meat products. For a determination of total vitamin B2 content in liver paste two preparation procedures are compared: acid and acid-enzymatic hydrolysis. The aim of this study thus, was to compare the effectiveness of these two different procedures for vitamin B2 content determination in liver paste. Methods. High pressure liquid chromatography (HPLC method with fluorescence detector, as specific and adequately sensitive for the foodstuff of a complex composition with a natural vitamin content, was used for determination of vitamin B2 in liver paste. Acid hydrolysis was performed with the application 0.1 M hydrochloric acid in a pressure cooker, and enzymatic hydrolysis was performed with the 10% takadiastase on 45 ºC within four hours. Ten samples of liver paste from the supply of the Serbian Army were examined. Separation was performed on the analytical column Nucleosil 50−5 C18 with mobile phase 450 ml CH3OH + 20 ml 5 mM CH3COONH4, and detection on the fluorescent detector with the variable wave length. Both methods were validated: examining a detection limit, quantification limit, specificity (because of a possible B2 vitamin interference with reagents, linearity of a peak area and standard concentration of B2 vitamin ratio in the range from 0.05 μg/ml to 2 μg/ml, precision for the 0.05 μg/ml concentration and recovery. Results. All the previously examined parameters validated both methods as specific, precise and reproductive, with a high recovery (98.5% for acid and 98.2% for acid - enzymatic hydrolysis, as well as linearity in a range that significantly superseded the expected content in

  16. Direct observation of superconducting gaps in MgB 2 by angle-resolved photoemission spectroscopy

    Souma, S.; Machida, Y.; Sato, T.; Takahashi, T.; Matsui, H.; Wang, S.-C.; Ding, H.; Kaminski, A.; Campuzano, J. C.; Sasaki, S.; Kadowaki, K.

    2004-08-01

    High-resolution angle-resolved photoemission spectroscopy has been carried out to clarify the anomalous superconductivity of MgB 2. We observed three bands crossing the Fermi level, which are ascribed to B2p-σ, π and surface bands. We have succeeded for the first time in directly observing the superconducting gaps of these bands separately. We have found that the superconducting-gap sizes of σ and surface bands are 6.5 ± 0.5 and 6.0 ± 0.5 meV, respectively, while that of the π band is much smaller (1.5 ± 0.5 meV). The present experimental result unambiguously demonstrates the validity of the two-band superconductivity in MgB 2.

  17. Direct observation of superconducting gaps in MgB2 by angle-resolved photoemission spectroscopy

    Souma, S.; Machida, Y.; Sato, T.; Takahashi, T.; Matsui, H.; Wang, S.-C.; Ding, H.; Kaminski, A.; Campuzano, J.C.; Sasaki, S.; Kadowaki, K.

    2004-01-01

    High-resolution angle-resolved photoemission spectroscopy has been carried out to clarify the anomalous superconductivity of MgB 2 . We observed three bands crossing the Fermi level, which are ascribed to B2p-σ, π and surface bands. We have succeeded for the first time in directly observing the superconducting gaps of these bands separately. We have found that the superconducting-gap sizes of σ and surface bands are 6.5 ± 0.5 and 6.0 ± 0.5 meV, respectively, while that of the π band is much smaller (1.5 ± 0.5 meV). The present experimental result unambiguously demonstrates the validity of the two-band superconductivity in MgB 2

  18. B1 to B2 structural phase transition in LiF under pressure

    Jain, Aayushi; Dixit, R. C.

    2018-05-01

    In the last few decades the alkali halides emerged as crystals with useful applications and their high-pressure behaviour is the most intensively studied subject in high-pressure physics/chemistry, material science, and geosciences. Most alkali halides follow the B1 (NaCl-type)→B2 (CsCl-type) phase-transition route under pressure. In the present paper, we have investigated the characteristics of structural phase transition that occurred in Lithium Florid compound under high pressure. The transition pressure of B1-B2 was calculated using an effective interionic interaction potential (EIOP). The changes of the characteristics of crystals like, Gibbs free energy, cohesive energy, volume collapse, and lattice constant are calculated for the B1 and B2 structures. These data were compared with the available experimental and theoretical data.

  19. Nuclear reactors

    Prescott, R F; George, B V; Baglin, C J

    1978-05-10

    Reference is made to thermal insulation on the inner surfaces of containment vessels of fluid cooled nuclear reactors and particularly in situations where the thermal insulation must also serve a structural function and transmit substantial load forces to the surface which it covers. An arrangement is described that meets this requirement and also provides for core support means that favourably influences the flow of hot coolant from the lower end of the core into a plenum space in the hearth of the reactor. The arrangement comprises a course of thermally insulating bricks arranged as a mosaic covering a wall of the reactor and a course of thermally insulating tiles arranged as a mosaic covering the course of bricks. Full constructional details are given.

  20. Nuclear reactors

    Prescott, R.F.; George, B.V.; Baglin, C.J.

    1978-01-01

    Reference is made to thermal insulation on the inner surfaces of containment vessels of fluid cooled nuclear reactors and particularly in situations where the thermal insulation must also serve a structural function and transmit substantial load forces to the surface which it covers. An arrangement is described that meets this requirement and also provides for core support means that favourably influences the flow of hot coolant from the lower end of the core into a plenum space in the hearth of the reactor. The arrangement comprises a course of thermally insulating bricks arranged as a mosaic covering a wall of the reactor and a course of thermally insulating tiles arranged as a mosaic covering the course of bricks. Full constructional details are given. (UK)

  1. Bioconversion reactor

    McCarty, Perry L.; Bachmann, Andre

    1992-01-01

    A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

  2. Plexin-B2 negatively regulates macrophage motility, Rac, and Cdc42 activation.

    Kelly E Roney

    Full Text Available Plexins are cell surface receptors widely studied in the nervous system, where they mediate migration and morphogenesis though the Rho family of small GTPases. More recently, plexins have been implicated in immune processes including cell-cell interaction, immune activation, migration, and cytokine production. Plexin-B2 facilitates ligand induced cell guidance and migration in the nervous system, and induces cytoskeletal changes in overexpression assays through RhoGTPase. The function of Plexin-B2 in the immune system is unknown. This report shows that Plexin-B2 is highly expressed on cells of the innate immune system in the mouse, including macrophages, conventional dendritic cells, and plasmacytoid dendritic cells. However, Plexin-B2 does not appear to regulate the production of proinflammatory cytokines, phagocytosis of a variety of targets, or directional migration towards chemoattractants or extracellular matrix in mouse macrophages. Instead, Plxnb2(-/- macrophages have greater cellular motility than wild type in the unstimulated state that is accompanied by more active, GTP-bound Rac and Cdc42. Additionally, Plxnb2(-/- macrophages demonstrate faster in vitro wound closure activity. Studies have shown that a closely related family member, Plexin-B1, binds to active Rac and sequesters it from downstream signaling. The interaction of Plexin-B2 with Rac has only been previously confirmed in yeast and bacterial overexpression assays. The data presented here show that Plexin-B2 functions in mouse macrophages as a negative regulator of the GTPases Rac and Cdc42 and as a negative regulator of basal cell motility and wound healing.

  3. SoxB2 in sea urchin development: implications in neurogenesis, ciliogenesis and skeletal patterning.

    Anishchenko, Evgeniya; Arnone, Maria Ina; D'Aniello, Salvatore

    2018-01-01

    Current studies in evolutionary developmental biology are focused on the reconstruction of gene regulatory networks in target animal species. From decades, the scientific interest on genetic mechanisms orchestrating embryos development has been increasing in consequence to the fact that common features shared by evolutionarily distant phyla are being clarified. In 2011, a study across eumetazoan species showed for the first time the existence of a highly conserved non-coding element controlling the SoxB2 gene, which is involved in the early specification of the nervous system. This discovery raised several questions about SoxB2 function and regulation in deuterostomes from an evolutionary point of view. Due to the relevant phylogenetic position within deuterostomes, the sea urchin Strongylocentrotus purpuratus represents an advantageous animal model in the field of evolutionary developmental biology. Herein, we show a comprehensive study of SoxB2 functions in sea urchins, in particular its expression pattern in a wide range of developmental stages, and its co-localization with other neurogenic markers, as SoxB1 , SoxC and Elav . Moreover, this work provides a detailed description of the phenotype of sea urchin SoxB2 knocked-down embryos, confirming its key function in neurogenesis and revealing, for the first time, its additional roles in oral and aboral ectoderm cilia and skeletal rod morphology. We concluded that SoxB2 in sea urchins has a neurogenic function; however, this gene could have multiple roles in sea urchin embryogenesis, expanding its expression in non-neurogenic cells. We showed that SoxB2 is functionally conserved among deuterostomes and suggested that in S. purpuratus this gene acquired additional functions, being involved in ciliogenesis and skeletal patterning.

  4. Cannabinoids reduce ErbB2-driven breast cancer progression through Akt inhibition

    Flores Juana M

    2010-07-01

    Full Text Available Abstract Background ErbB2-positive breast cancer is characterized by highly aggressive phenotypes and reduced responsiveness to standard therapies. Although specific ErbB2-targeted therapies have been designed, only a small percentage of patients respond to these treatments and most of them eventually relapse. The existence of this population of particularly aggressive and non-responding or relapsing patients urges the search for novel therapies. The purpose of this study was to determine whether cannabinoids might constitute a new therapeutic tool for the treatment of ErbB2-positive breast tumors. We analyzed their antitumor potential in a well established and clinically relevant model of ErbB2-driven metastatic breast cancer: the MMTV-neu mouse. We also analyzed the expression of cannabinoid targets in a series of 87 human breast tumors. Results Our results show that both Δ9-tetrahydrocannabinol, the most abundant and potent cannabinoid in marijuana, and JWH-133, a non-psychotropic CB2 receptor-selective agonist, reduce tumor growth, tumor number, and the amount/severity of lung metastases in MMTV-neu mice. Histological analyses of the tumors revealed that cannabinoids inhibit cancer cell proliferation, induce cancer cell apoptosis, and impair tumor angiogenesis. Cannabinoid antitumoral action relies, at least partially, on the inhibition of the pro-tumorigenic Akt pathway. We also found that 91% of ErbB2-positive tumors express the non-psychotropic cannabinoid receptor CB2. Conclusions Taken together, these results provide a strong preclinical evidence for the use of cannabinoid-based therapies for the management of ErbB2-positive breast cancer.

  5. [Immunoexpression of c-erbB-2 in intraductal proliferative lesions of the female breast].

    Oliveira, Agliberto Barbosa de; De Luca, Laurival Antônio; Carvalho, Grigna Teixeira; Arias, Victor Eduardo Arua; Carvalho, Lídia Raquel de; Assunção, Maria do Carmo

    2004-01-01

    Genetic modifications are related to genesis and development of cancer. Neoplasias in various organs express the c-erbB-2 oncogene. In intraductal proliferations of the breast it has been assessed as a risk factor for subsequent development of carcinoma. The c-erbB-2 immunoexpression in intraductal epithelial proliferations and the relationship with histopathological characteristics of ductal carcinoma in situ (DCIS) were evaluated. File material from 88 women, which were tissue samples formalin-fixed, paraffin-embedded blocks, was used. Of these 51 presented with DCIS and 37 with ductal hyperplasia without atypia. Ages of the women ranged from 35 to 76 years. All cases were reviewed and nuclear grade, presence of necrosis, preponderance of histological subtype and its extension were verified. Specimens were obtained for the c-erB-2 immunohistochemical study of 84 of the women in question. No expression of the oncogene was verified in the hyperplasias without atypias and in tissues adjacent to all tissue samples. Expression of c-erbB-2 was verified in 9 (19.1%) of the DCIS (p = 0.0001). Immunoexpression was not related to the extension of the lesions. The c-erbB-2 immunoexpression in DCIS was correlated to the histological subtype (p = 0.019), necrosis (p = 0.0066), nuclear grade (p = 0.0084) and Van Nuys Classification (p = 0.039). Expression of c-erbB-2 was significant in proliferative lesions with risk (DCIS) and was correlated to histopathological characteristics: high nuclear grade, presence of necrosis and comedy subtype. There was no expression in the hyperplasias without atypias and adjacent tissues.

  6. TiB2 reinforced aluminum based in situ composites fabricated by stir casting

    Chen, Fei; Chen, Zongning; Mao, Feng; Wang, Tongmin; Cao, Zhiqiang

    2015-01-01

    In this study, a new technique involving mechanical stirring at the salts/aluminum interface was developed to fabricate TiB 2 particulate reinforced aluminum based in situ composites with improved particle distribution. Processing parameters in terms of stirring intensity, stirring duration and stirring start time were optimized according to the microstructure and mechanical properties evaluation. The results show that, the first and last 15 min of the entire 60 min holding are of prime importance to the particle distribution of the final composites. When applying 180 rpm (revolutions per minute) stirring at the salts/aluminum interface in these two intervals, a more uniform microstructure can be achieved and the Al-4 wt% TiB 2 composite thus produced exhibits superior mechanical performance. Synchrotron radiation X-ray computed tomography (SR-CT) was used to give a full-scale imaging of the particle distribution. From the SR-CT results, the in situ Al–xTiB 2 composites (x=1, 4 and 7, all in wt%) fabricated by the present technique are characterized by fine and clean TiB 2 particles distributed uniformly throughout the Al matrix. These composites not only have higher yield strength (σ 0.2 ) and ultimate tensile strength (UTS), but also exhibit superior ductility, with respect to the Al–TiB 2 composites fabricated by the conventional process. The σ 0.2 and UTS of the Al–7TiB 2 composite in the present work, are 260% and 180% higher than those of the matrix. A combined mechanism was also presented to interpret the improvements in yield strength of the composites as influenced by their microstructures and processing history. The predicted values are in good agreement with the experimental results, strongly supporting the strengthening mechanism we proposed. Fractography reveals that the composites thus fabricated, follow ductile fracture mechanism in spite of the presence of stiff reinforcements

  7. Low-temperature synthesis of superconducting nanocrystalline MgB2

    Lu, J.; Xiao, Z.; Lin, Q.; Claus, H.; Fang, Z.Z.

    2010-01-01

    Magnesium diboride (MgB 2 ) is considered a promising material for practical application in superconducting devices, with a transition temperature near 40 K. In the present paper, nanocrystalline MgB 2 with an average particle size of approximately 70 nm is synthesized by reacting LiBH 4 with MgH 2 at temperatures as low as 450 C. This synthesis approach successfully bypasses the usage of either elemental boron or toxic diborane gas. The superconductivity of the nanostructures is confirmed by magnetization measurements, showing a superconducting critical temperature of 38.7 K.

  8. Social media as a support tool for B2B communication

    Thapa Magar, Chandani

    2016-01-01

    This research was commissioned by Oulu University of Applied Sciences and a Finnish tech company Uros Ltd. As social media adoption is growing steadily in the contemporary consumer marketing, not many cases can be found where Social Media has been successfully adopted and used in a B2B scenario. Thus, it has remained as a reserved matter for many B2B companies, which still follow the tried-and-true business principles polished through traditional marketing. This research paper aims to enhanc...

  9. Short syntheses of enantiopure calystegine B-2, B-3, and B-4

    Skaanderup, Philip Robert; Madsen, Robert

    2001-01-01

    Calystegine B-2 B-3, and B-4 have been prepared in 5 steps from the benzyl protected methyl 6-iodoglycopyranosides of glucose, galactose and mannose, respectively, by using a zinc-mediated domino reaction followed by ring-closing olefin metathesis as the key steps.......Calystegine B-2 B-3, and B-4 have been prepared in 5 steps from the benzyl protected methyl 6-iodoglycopyranosides of glucose, galactose and mannose, respectively, by using a zinc-mediated domino reaction followed by ring-closing olefin metathesis as the key steps....

  10. Extreme ultraviolet spectroscopy of G191-B2B - Direct observation of ionization edges

    Wilkinson, Erik; Green, James C.; Cash, Webster

    1992-01-01

    We present the first spectrum of the hot, DA white dwarf G191-B2B (wd 0501 + 527) between 200 and 330 A. The spectrum, which has about 2 A resolution, was obtained with a sounding rocket-borne, grazing incidence spectrograph. The spectrum shows no evidence of He II, the expected primary opacity source in this wavelength region. Three ionization edges and one absorption feature were observed and are suggestive of O III existing in the photosphere of G191-B2B. Also noted is a broad spectral depression that may result from Fe VI in the photosphere.

  11. Crystallinity and flux pinning properties of MgB2 bulks

    Yamamoto, A.; Shimoyama, J.; Ueda, S.; Katsura, Y.; Iwayama, I.; Horii, S.; Kishio, K.

    2006-01-01

    The relationship between flux pinning properties and crystallinity of MgB 2 bulks was systematically studied. Improved flux pinning properties under high fields were observed for samples with low crystallinity. Increased impurity scattering due to strain and defects in lattice corresponding to the degraded crystallinity was considered to enhance flux pinning strength at grain boundaries. Low-temperature synthesis and carbon substitution were confirmed to be effective for degrading crystallinity of MgB 2 bulks, resulting in high critical current properties under high fields

  12. Sociala Medier som kommunikationskanal för B2B-företag

    Kaddura, Layla; Olsson, Karin

    2010-01-01

    The purpose of this thesis is to show what advantages and opportunities social media offer for B2B-companies (business-to-business), and how they can be used for marketing communications. We have studied how companies can use social media, for example evolving the organization, developing products/services, staying up-to-date, building relations, creating customer loyalty and engagement, building the company’s identity and image, and affecting the buying decisions. We have also studied how B2...

  13. Properties of stabilized MgB2 composite wire with Ti barrier

    Kovac, P; Husek, I; Melisek, T; Holubek, T

    2007-01-01

    Stabilized four-filament in situ MgB 2 /Ti/Cu/Monel composite wire was produced by the rectangular wire-in-tube (RWIT) technique. 10 wt% of nanosize SiC was added into the Mg-B powder mixture, which was packed into the Ti/Cu and Monel tubes, respectively. The assembled composite was two-axially rolled into wire and/or tape form and sintered at temperatures of 650-850 deg. C/0.5 h. Stabilized MgB 2 wire with Ti barrier is studied in terms of field-dependent transport critical current density, effects of filament size reduction and thermal stability

  14. China's B2C e-commerce development and its future prospects

    Jin, Guming

    2012-01-01

    China’s E-commerce environment is improving all the time. Consumers are getting more and more habituated to this form of consumption mode. The recent trend shows that China’s e- commerce market is booming mainly because of major enterprises’ fierce competition within Business To Customer E-commerce market. People are optimistic about B2C E-commerce which strengthens the China’s B2C E-commerce market. Even though E-commerce business in China is soaring, there still persists a problem, too. ...

  15. Laser-induced thermoelectric voltage in normal state MgB2 thin films

    Zhao Songqing; Zhou Yueliang; Zhao Kun; Wang Shufang; Chen Zhenghao; Jin Kuijuan; Lue Huibin; Cheng Bolin; Yang Guozhen

    2006-01-01

    Laser-induced voltage has been observed in c-axis oriented MgB 2 thin film at room temperature. The amplitude of the signal is approximately proportional to the film thickness. For the film with the thickness of 150 nm, a very fast response has been detected when the film was irradiated by a 308 nm pulsed laser of 20 ns duration. The rise time and full width at half-maximum of the signal are about 3 and 25 ns, respectively. The physical origin of the laser-induced voltage can be attributed to a transverse thermoelectricity due to the anisotropic thermopower in MgB 2

  16. MgB2 ultrathin films fabricated by hybrid physical chemical vapor deposition and ion milling

    Narendra Acharya

    2016-08-01

    Full Text Available In this letter, we report on the structural and transport measurements of ultrathin MgB2 films grown by hybrid physical-chemical vapor deposition followed by low incident angle Ar ion milling. The ultrathin films as thin as 1.8 nm, or 6 unit cells, exhibit excellent superconducting properties such as high critical temperature (Tc and high critical current density (Jc. The results show the great potential of these ultrathin films for superconducting devices and present a possibility to explore superconductivity in MgB2 at the 2D limit.

  17. Modelling the B2C Marketplace: Evaluation of a Reputation Metric for e-Commerce

    Gutowska, Anna; Sloane, Andrew

    This paper evaluates recently developed novel and comprehensive reputation metric designed for the distributed multi-agent reputation system for the Business-to-Consumer (B2C) E-commerce applications. To do that an agent-based simulation framework was implemented which models different types of behaviours in the marketplace. The trustworthiness of different types of providers is investigated to establish whether the simulation models behaviour of B2C e-Commerce systems as they are expected to behave in real life.

  18. Preparation of MgB2 superconducting microbridges by focused ion beam direct milling

    Zhang, Xuena; Li, Yanli; Xu, Zhuang; Kong, Xiangdong; Han, Li

    2017-01-01

    MgB2 superconducting microbridges were prepared by focused ion beam (FIB) direct milling on MgB2 films. The surface topography of the microbridges were observed using SEM and AFM and the superconductivity was measured in this paper. Lots of cracks and holes were found near the milled area. And the superconducting transition temperature was decreased a lot and the bridges prepared were not superconducting due to ion damage after milled with large dose. Through these works, we explored the effect regular of FIB milling and experimental parameters on the performance of microbridges.

  19. Structural and electronic properties of OsB2 : A hard metallic material

    Chen, Z. Y.; Xiang, H. J.; Yang, Jinlong; Hou, J. G.; Zhu, Qingshi

    2006-07-01

    We calculate the structural and electronic properties of OsB2 using density functional theory with or without taking into account the spin-orbit (SO) interaction. Our results show that the bulk modulus with and without SO interactions are 364 and 365GPa , respectively, both are in good agreement with experiment (365-395GPa) . The evidence of covalent bonding of Os-B, which plays an important role to form a hard material, is indicated both in charge density, atoms in molecules analysis, and density of states analysis. The good metallicity and hardness of OsB2 might suggest its potential application as hard conductors.

  20. Superconducting and normal state properties of carbon doped and neutron irradiated MgB2

    Wilke, R.H.T.; Samuely, P.; Szabo, P.; Holanova, Z.; Bud'ko, S.L.; Canfield, P.C.; Finnemore, D.K.

    2007-01-01

    Current research in MgB 2 focuses on the effects various types of perturbations have on the superconducting properties of this novel two-gap superconductor. In this article we summarize the effects of carbon doping and neutron irradiation in bulk MgB 2 . Low levels of carbon doping and light neutron irradiation result in significant enhancements in H c2 . At high fluences, where superconductivity is nearly fully suppressed, superconductivity can be restored through post exposure annealing. However, this results in a change in the interdependencies of the normal state and superconducting properties (ρ 0 , T c , H c2 ), with little or no enhancement in H c2

  1. Linkage of genes for laminin B1 and B2 subunits on chromosome 1 in mouse.

    Elliott, R W; Barlow, D; Hogan, B L

    1985-08-01

    We have used cDNA clones for the B1 and B2 subunits of laminin to find restriction fragment length DNA polymorphisms for the genes encoding these polypeptides in the mouse. Three alleles were found for LamB2 and two for LamB1 among the inbred mouse strains. The segregation of these polymorphisms among recombinant inbred strains showed that these genes are tightly linked in the central region of mouse Chromosome 1 between Sas-1 and Ly-m22, 7.4 +/- 3.2 cM distal to the Pep-3 locus. There is no evidence in the mouse for pseudogenes for these proteins.

  2. The preliminary study of the quench protection of an MgB2

    Juster, F. P.; Berriaud, C.; Bonelli, A.; Pasquet, R.; Przybilski, H.; Schild, T.; Scola, L.

    2014-01-01

    In the framework of general studies currently carried out at CEA/Saclay in collaboration with Sigmaphi Company on dry MgB2 magnet operating at 10 K and medium range field, 1 T up to 4 T., we plan to build a prototype-coil with a commercial MgB2 wire. This coil, the nominal axial magnetic field of which is 1 tesla, will be placed in a 3 teslas background field generated by a classical NbTi coil. This paper deals with the preliminary quench protection studies including stability and quench propagation modeling.

  3. Amygdala EphB2 Signaling Regulates Glutamatergic Neuron Maturation and Innate Fear.

    Zhu, Xiao-Na; Liu, Xian-Dong; Zhuang, Hanyi; Henkemeyer, Mark; Yang, Jing-Yu; Xu, Nan-Jie

    2016-09-28

    The amygdala serves as emotional center to mediate innate fear behaviors that are reflected through neuronal responses to environmental aversive cues. However, the molecular mechanism underlying the initial neuron responses is poorly understood. In this study, we monitored the innate defensive responses to aversive stimuli of either elevated plus maze or predator odor in juvenile mice and found that glutamatergic neurons were activated in amygdala. Loss of EphB2, a receptor tyrosine kinase expressed in amygdala neurons, suppressed the reactions and led to defects in spine morphogenesis and fear behaviors. We further found a coupling of spinogenesis with these threat cues induced neuron activation in developing amygdala that was controlled by EphB2. A constitutively active form of EphB2 was sufficient to rescue the behavioral and morphological defects caused by ablation of ephrin-B3, a brain-enriched ligand to EphB2. These data suggest that kinase-dependent EphB2 intracellular signaling plays a major role for innate fear responses during the critical developing period, in which spinogenesis in amygdala glutamatergic neurons was involved. Generation of innate fear responses to threat as an evolutionally conserved brain feature relies on development of functional neural circuit in amygdala, but the molecular mechanism remains largely unknown. We here identify that EphB2 receptor tyrosine kinase, which is specifically expressed in glutamatergic neurons, is required for the innate fear responses in the neonatal brain. We further reveal that EphB2 mediates coordination of spinogenesis and neuron activation in amygdala during the critical period for the innate fear. EphB2 catalytic activity plays a major role for the behavior upon EphB-ephrin-B3 binding and transnucleus neuronal connections. Our work thus indicates an essential synaptic molecular signaling within amygdala that controls synapse development and helps bring about innate fear emotions in the postnatal

  4. Characterization of metabolites from a strain of Aspergillus flavus accumulating aflatoxin B2

    Dutton, M.F.

    1985-01-01

    A number of aflatoxins and anthraquinone pigments were isolated from a strain of Aspergillus flavus, several of which were fully characterized. The major metabolites isolated were aflatoxin B 2 and versicolorin C, which are normally only found as minor products from species of the genus Aspergillus. The identification of these products supports the proposal that aflatoxin B 2 can arise independently of aflatoxin B 1 and that, in this case, the branch in the pathway occurs at the versicolorins. Other metabolites charaterized were aflatoxin M 2 , norsolorinic acid, and averufin

  5. Evaluation of carbon incorporation and strain of doped MgB2 superconductor by Raman spectroscopy

    Yeoh, W.K.; Zheng, R.K.; Ringer, S.P.; Li, W.X.; Xu, X.; Dou, S.X.; Chen, S.K.; MacManus-Driscoll, J.L.

    2011-01-01

    Raman spectroscopy is employed to study both the strain and the carbon substitution level in SiC-doped MgB 2 bulk samples. Raman spectroscopy was demonstrated to be a better method to distinguish the individual influences of strain and carbon than standard X-ray diffraction. It is found that the lattice parameter correlation method for C content determination is invalid for highly strained samples. Our result also provides an alternative explanation for lattice variation in non-carbon-doped MgB 2 , which is basically due to lattice strain.

  6. Defect structures in MgB2 wires introduced by hot isostatic pressing

    Liao, X Z; Serquis, A; Zhu, Y T; Civale, L; Hammon, D L; Peterson, D E; Mueller, F M; Nesterenko, V F; Gu, Y

    2003-01-01

    The microstructures of MgB 2 wires prepared by the powder-in-tube technique and subsequent hot isostatic pressing were investigated using transmission electron microscopy. A large amount of crystalline defects including small-angle twisting, tilting and bending boundaries, in which high densities of dislocations reside, was found forming sub-grains within MgB 2 grains. It is believed that these defects resulted from particle deformation during the hot isostatic pressing process and are effective flux pinning centres that contribute to the high critical current densities of the wires at high temperatures and at high fields

  7. Using Fast Hot Shock Wave Consolidation Technology to Produce Superconducting MgB2

    T. Gegechkori

    2018-02-01

    Full Text Available The original hot shock wave assisted consolidation method combining high temperature was applied with the two-stage explosive process without any further sintering to produce superconducting materials with high density and integrity. The consolidation of MgB2 billets was performed at temperatures above the Mg melting point and up to 1000oC in partially liquid condition of Mg-2B blend powders. The influence of the type of boron (B isotope in the composition on critical temperature and superconductive properties was evaluated. An example of a hybrid Cu-MgB2–Cu superconducting tube is demonstrated and conclusions are discussed.

  8. Nuclear reactor

    Scholz, M.

    1976-01-01

    An improvement of the accessibility of that part of a nuclear reactor serving for biological shield is proposed. It is intended to provide within the biological shield, distributed around the circumference of the reactor pressure vessel, several shielding chambers filled with shielding material, which are isolated gastight from the outside by means of glass panes with a given bursting strength. It is advantageous that, on the one hand, inspection and maintenance will be possible without great effort and, on the other, a large relief cross section will be at desposal if required. (UWI) [de

  9. NEUTRONIC REACTOR

    Wigner, E.P.; Weinberg, A.W.; Young, G.J.

    1958-04-15

    A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

  10. Multiscale Modeling of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2: Application to Lattice Thermal Conductivity

    Lawson, John W.; Daw, Murray S.; Squire, Thomas H.; Bauschlicher, Charles W.

    2012-01-01

    We are developing a multiscale framework in computational modeling for the ultra high temperature ceramics (UHTC) ZrB2 and HfB2. These materials are characterized by high melting point, good strength, and reasonable oxidation resistance. They are candidate materials for a number of applications in extreme environments including sharp leading edges of hypersonic aircraft. In particular, we used a combination of ab initio methods, atomistic simulations and continuum computations to obtain insights into fundamental properties of these materials. Ab initio methods were used to compute basic structural, mechanical and thermal properties. From these results, a database was constructed to fit a Tersoff style interatomic potential suitable for atomistic simulations. These potentials were used to evaluate the lattice thermal conductivity of single crystals and the thermal resistance of simple grain boundaries. Finite element method (FEM) computations using atomistic results as inputs were performed with meshes constructed on SEM images thereby modeling the realistic microstructure. These continuum computations showed the reduction in thermal conductivity due to the grain boundary network.

  11. B2B or B2C? Dutch approaches towards marketing and the consumer, 1945-1968, with particular attention to Heineken’s Brewery

    Keetie Sluyterman

    2017-09-01

    Full Text Available In this article I analyse how Dutch companies approached the consumers and marketing during the years 1945-1968, a period during which the Netherlands became a ‘consumer society’. In the first part I examine articles in the Dutch journal Tijdschrift voor Efficiëntie en Documentatie (ted, or Journal for Efficiency and Documentation, a leading management periodical. This examination shows how new ideas from abroad were taken up and disseminated in the Netherlands by both management consultants and large producers of consumer goods such as Unilever and Philips. In the second part of this article I take a closer look at Heineken’s brewery, drawing on the company’s archives. Heineken closely followed the ideas afloat at the time and put them intopractice. However, the Heineken case also shows the different approaches necessary for business-to-consumer (b2c and business-to-business (b2b relationships. The second type of relationships deserves more attention from historians.

  12. Quantitative electron microscopy and spectroscopy of MgB2 wires and tapes

    Birajdar, B; Peranio, N; Eibl, O

    2008-01-01

    In MgB 2 the correlation of microstructure with superconducting properties, in particular the critical current density, requires powerful analytical tools. Critical current densities and electrical resistivities of different MgB 2 superconductors differ by orders of magnitudes and the current limiting mechanisms have not been fully understood. Granularity of MgB 2 is one significant reason for reduced critical current densities and is introduced intrinsically by the anisotropy of B c2 but also extrinsically by the microstructure of the material. B c2 enhancement by doping is another important challenge for chemical analysis and, at present, doping levels are not well controlled on the sub-μm scale. In this paper the quantitative electron microscopy and spectroscopy methods essential for the microstructural analysis of MgB 2 are described. By quantitative electron microscopy and spectroscopy we mean a combined SEM and TEM analysis that covers various length scales from μm to nm. Contamination-free sample preparation, chemical mapping including B, and advanced chemical quantification using x-ray microanalysis were essential elements of the applied methodology. The methodology was applied to in situ and ex situ MgB 2 wires and tapes with and without SiC additives. Quantitative B analysis by EDX spectroscopy was applied quantitatively in the SEM and TEM, which is a major achievement. Although MgB 2 is a binary system, the thermodynamics of phase formation is complex, and the complexity is dramatically increased if additives like SiC are used. The small, sub-μm grain sizes of the matrix and secondary phases require TEM methods. However, granularity on the μm scale was also identified and underlines the importance of the combined SEM and TEM studies. Significant differences in the microstructure were observed for in situ and ex situ samples. This holds particularly if SiC was added and yielded Mg 2 Si for in situ samples annealed at 600-650 deg. C and Mg-Si-O phases

  13. Neutrino oscillations in Gallium and reactor experiments and cosmological effects of a light sterile neutrino

    Acero-Ortega, Mario Andres

    2009-01-01

    Neutrino oscillations is a very well studied phenomenon and the observations from Solar, very-long-baseline Reactor, Atmospheric and Accelerator neutrino oscillation experiments give very robust evidence of three-neutrino mixing. On the other hand, some experimental data have shown anomalies that could be interpreted as indication of exotic neutrino physics beyond three-neutrino mixing. Furthermore, from a cosmological point of view, the possibility of extra light species contributing as a subdominant hot (or warm) component of the Universe is still interesting. In the first part of this Thesis, we focused on the anomaly observed in the Gallium radioactive source experiments. These experiments were done to test the Gallium solar neutrino detectors GALLEX and SAGE, by measuring the electron neutrino flux produced by intense artificial radioactive sources placed inside the detectors. The measured number of events was smaller than the expected one. We interpreted this anomaly as a possible indication of the disappearance of electron neutrinos and, in the effective framework of two-neutrino mixing, we obtained sin 2 2θ ≥ 0.03 and Δm 2 ≥ 0.1 eV 2 . We also studied the compatibility of this result with the data of the Bugey and Chooz reactor antineutrino disappearance experiments. We found that the Bugey data present a hint of neutrino oscillations with 0.02 ≤ sin 2 2θ ≤ 0.07 and Δm 2 ≅ 1.95 eV 2 , which is compatible with the Gallium allowed region of the mixing parameters. Then, combining the data of Bugey and Chooz, the data of Gallium and Bugey, and the data of Gallium, Bugey and Chooz, we found that this hint persists, with an acceptable compatibility of the experimental data. Furthermore, we analyzed the experimental data of the I.L.L., S.R.S, and Gosgen nuclear Reactor experiments. We obtained a good fit of the I.L.L. data, showing 1 and 2σ allowed regions in the oscillation parameters space. However, the combination of I.L.L. data with the Bugey

  14. 3 CFR - Presidential Determination for the Kingdom of Cambodia Under Section 2(b)(2) of the Export-Import...

    2010-01-01

    ... Cambodia Under Section 2(b)(2) of the Export-Import Bank Act of 1945, as amended Presidential Documents... Determination for the Kingdom of Cambodia Under Section 2(b)(2) of the Export-Import Bank Act of 1945, as... the Export-Import Bank Act of 1945, as amended (12 U.S.C. 635(b)(2)(C)), I hereby determine that the...

  15. User-Interface Design Characteristics of Fortune 500 B2C E-Commerce Sites and Industry Differences

    Zhao, Jensen J.; Truell, Allen D.; Alexander, Melody W.

    2006-01-01

    This study examined the user-interface design characteristics of 107 Fortune 500 B2C e-commerce Web sites and industry differences. Data were collected from corporate homepages, B2C product/service pages, B2C interactive shopping pages, as well as customer satisfaction of 321 online shoppers. The findings indicate that (a) to attract online…

  16. Bradykinin B2 receptor expression in the bronchial mucosa of allergic asthmatics: the role of NF-kB

    Ricciardolo, F. L. M.; Petecchia, L.; Sorbello, V.; Di Stefano, A.; Usai, C.; Massaglia, G. M.; Gnemmi, I.; Mognetti, B.; Hiemstra, P. S.; Sterk, P. J.; Sabatini, F.

    2016-01-01

    Bradykinin (BK) mediates acute allergic asthma and airway remodelling. Nuclear factor-kappa B (NF-kB) is potentially involved in BK B2 receptor (B2R) regulation. In this observational cross-sectional study, B2R and NF-kB expression was evaluated in bronchial biopsies from mild asthmatics (after

  17. Neutronic reactor

    Wende, C.W.J.

    1976-01-01

    The method of operating a water-cooled neutronic reactor having a graphite moderator is described which comprises flowing a gaseous mixture of carbon dioxide and helium, in which the helium comprises 40--60 volume percent of the mixture, in contact with the graphite moderator. 2 claims, 4 figures

  18. Neutronic reactor

    Wende, C.W.J.

    1976-01-01

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield

  19. Reactor facility

    Suzuki, Hiroaki; Murase, Michio; Yokomizo, Osamu.

    1997-01-01

    The present invention provides a BWR type reactor facility capable of suppressing the amount of steams generated by the mutual effect of a failed reactor core and coolants upon occurrence of an imaginal accident, and not requiring spacial countermeasures for enhancing the pressure resistance of the container vessel. Namely, a means for supplying cooling water at a temperature not lower by 30degC than the saturated temperature corresponding to the inner pressure of the containing vessel upon occurrence of an accident is disposed to a lower dry well below the pressure vessel. As a result, upon occurrence of such an accident that the reactor core should be melted and flown downward of the pressure vessel, when cooling water at a temperature not lower than the saturated temperature, for example, cooling water at 100degC or higher is supplied to the lower dry well, abrupt generation of steams by the mutual effect of the failed reactor core and cooling water is scarcely caused compared with a case of supplying cooling water at a temperature lower than the saturation temperature by 30degC or more. Accordingly, the amount of steams to be generated can be suppressed, and special countermeasure is no more necessary for enhancing the pressure resistance of the container vessel is no more necessary. (I.S.)

  20. Nuclear reactor

    Gilroy, J.E.

    1980-01-01

    An improved cover structure for liquid metal cooled fast breeder type reactors is described which it is claimed reduces the temperature differential across the intermediate grid plate of the core cover structure and thereby reduces its subjection to thermal stresses. (UK)