WorldWideScience

Sample records for ardennes b-2 reactor

  1. Sediment budget and tectonic evolution of the Meuse catchment in the Ardennes and the Roer Valley Rift System

    NARCIS (Netherlands)

    Balen, R.T. van; Houtgast, R.F.; Wateren, F.M. van der; Berghe, J. van den; Bogaart, P.W.

    2000-01-01

    The Meuse river system is located in the northeastern part of the Paris Basin, the Ardennes, and the Roer Valley Rift System (RVRS). The Meuse river system developed during the uplift of the Ardennes since the Eocene and it was affected by renewed rifting of the RVRS starting in the Late Oligocene.

  2. Kettneraspis, Radiaspis and Ceratarges (Trilobita) from the Middle Devonian of the Rochefort area (Ardennes, Belgium)

    NARCIS (Netherlands)

    Viersen, van A.P.

    2007-01-01

    The Middle Eifelian trilobite fauna of the Belgian Ardennes shows close affinities with that of the German Eifel. Two trilobite taxa are recorded from Middle Eifelian strata near the town of Jemelle, on the southern border of the Dinant Synclinorium, Belgium. Kettneraspis bayarti sp. nov. is closely

  3. Soil piping in a temperate humid climate. The Flemish Ardennes (Belgium).

    OpenAIRE

    Verachtert, Els

    2011-01-01

    Collapsible loess-derived soils are prone to subsurface soil erosion (piping), whereenlargement of macropores may lead to a subsurface pipe network and eventuallyto soil collapse. This PhD aimed at understanding the factors controlling theoccurrence of collapsed pipes in the Flemish Ardennes. In total, 137 parcelswith 560 collapsed pipes were mapped, indicating significant soil losses in aland use –pasture– that is typically considered to be non-susceptible to surfaceerosion. Logistic regress...

  4. Reactors

    CERN Document Server

    International Electrotechnical Commission. Geneva

    1988-01-01

    This standard applies to the following types of reactors: shunt reactors, current-limiting reactors including neutral-earthing reactors, damping reactors, tuning (filter) reactors, earthing transformers (neutral couplers), arc-suppression reactors, smoothing reactors, with the exception of the following reactors: small reactors with a rating generally less than 2 kvar single-phase and 10 kvar three-phase, reactors for special purposes such as high-frequency line traps or reactors mounted on rolling stock.

  5. Spatial variability in channel and slope morphology within the Ardennes Massif, and its link with tectonics

    Directory of Open Access Journals (Sweden)

    N. Sougnez

    2010-09-01

    Full Text Available Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 years. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This work focuses on a wide range of slope and river channel morphometric indices to study their behavior and strength in regions affected by low to moderate tectonic activity. We selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm year−1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our data indicate that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronous, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.

  6. The topographic signature of Quaternary tectonic uplift in the Ardennes massif (Western Europe

    Directory of Open Access Journals (Sweden)

    N. Sougnez

    2011-04-01

    Full Text Available Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 y. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This study aims to analyze the link between tectonic uplift rates and landscape morphology based on slope and channel morphometric indexes. To achieve this objective, we selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif (a Palaeozoic massif of NW Europe, principally located in Belgium that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm yr−1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our analysis indicates that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronic, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.

  7. [Results and lessons after 10 years of universal neonatal hearing screening in the Champagne-Ardenne region of France].

    Science.gov (United States)

    Chays, André; Labrousse, Marc; Makeieff, Marc

    2014-01-01

    In France, universal newborn hearing screening has been mandatory since April23rd, 2012, but it began in the Champagne-Ardenne region on January 15th 2004. More than 99 % of 160 196 newborns have since been systematically screened in this region. Bilateral hearing impairment was thus identified in 116 infants when they were around 3.5 months old. Earlier diagnosis improves the outcome of deafness, which is only diagnosed around age 20 months without screening. The authors report their experience and the lessons learnt.

  8. B2B marketing

    OpenAIRE

    Pospíšilová, Lucie

    2010-01-01

    The main goal of this bachelor thesis is to apply theoretical knowledge in B2B marketing to the example of marketing processes in a particular company, to evaluate the current situation of its activities with regard to B2B principles and to suggest relevant recommendations. The theoretical part focuses on specific characteristics of B2B marketing, describes its differences from marketing on consumer markets, deals with buying behaviour of organizations and specifies particular features of mar...

  9. Comparison of two landslide susceptibility assessments in the Champagne-Ardenne region (France)

    Science.gov (United States)

    Den Eeckhaut, M. Van; Marre, A.; Poesen, J.

    2010-02-01

    The vineyards of the Montagne de Reims are mostly planted on steep south-oriented cuesta fronts receiving a maximum of sun radiation. Due to the location of the vineyards on steep hillslopes, the viticultural activity is threatened by slope failures. This study attempts to better understand the spatial patterns of landslide susceptibility in the Champagne-Ardenne region by comparing a heuristic (qualitative) and a statistical (quantitative) model in a 1120 km² study area. The heuristic landslide susceptibility model was adopted from the Bureau de Recherches Géologiques et Minières, the GEGEAA - Reims University and the Comité Interprofessionnel du Vin de Champagne. In this model, expert knowledge of the region was used to assign weights to all slope classes and lithologies present in the area, but the final susceptibility map was never evaluated with the location of mapped landslides. For the statistical landslide susceptibility assessment, logistic regression was applied to a dataset of 291 'old' (Holocene) landslides. The robustness of the logistic regression model was evaluated and ROC curves were used for model calibration and validation. With regard to the variables assumed to be important environmental factors controlling landslides, the two models are in agreement. They both indicate that present and future landslides are mainly controlled by slope gradient and lithology. However, the comparison of the two landslide susceptibility maps through (1) an evaluation with the location of mapped 'old' landslides and through (2) a temporal validation with spatial data of 'recent' (1960-1999; n = 48) and 'very recent' (2000-2008; n = 46) landslides showed a better prediction capacity for the statistical model produced in this study compared to the heuristic model. In total, the statistically-derived landslide susceptibility map succeeded in correctly classifying 81.0% of the 'old' and 91.6% of the 'recent' and 'very recent' landslides. On the susceptibility map

  10. Reactor

    Science.gov (United States)

    Evans, Robert M.

    1976-10-05

    1. A neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch.

  11. Mixed brittle-plastic deformation behaviour in a slate belt. Examples from the High-Ardenne slate belt (Belgium, Germany)

    Science.gov (United States)

    Sintubin, Manuel; van Baelen, Hervé; van Noten, Koen; Muchez, Philippe

    2010-05-01

    In the High-Ardenne slate belt, part of the Rhenohercynian external fold-and-thrust belt at the northern extremity of the Late Palaeozoic Variscan orogen (Belgium, Germany, France), particular quartz vein occurrences can be observed in predominantly fine-grained siliciclastic metasediments. Detailed structural, petrographical and geochemical studies has revealed that these vein occurrences can be related to a mixed brittle-plastic deformation behaviour in a low-grade metamorphic mid-crustal environment. The first type of quartz veins are bedding-perpendicular, lens-shaped extension veins that are confined to the sandstone layers within the multilayer sequence. Fluid inclusion studies demonstrate high fluid pressures suggesting that the individual sandstone bodies acted as isolated high-pressure compartments in an overpressured basin. Hydraulic fracturing occurred during the tectonic inversion (from extension to compression) in the earliest stages of the Variscan orogeny. The vein fill shows a blocky character indicating crystal growth in open cavities. Both the typical lens shape of the veins and the subsequent cuspate-lobate folding of the bed interfaces in between the quartz veins suggest plastic deformation of cohesionless fluid-filled fissures. Metamorphic grade of the host rock and fluid temperature and pressure clearly indicates mid-crustal conditions below the brittle-plastic transition. This first type of quartz veins exemplifies mixed brittle-plastic deformation behaviour, possibly related to a transient deepening of the brittle-plastic transition. This is in contrast with contemporaneous bedding-perpendicular crack-seal veins observed in higher - upper-crustal - structural levels in the slate belt, reflecting pure brittle deformation behaviour. The second type are discordant quartz veins confined to extensional low-angle detachment shear zones. These very irregular veins transect a pre-existing pervasive cleavage fabric. They show no matching walls and

  12. CIAE Signs Contract on B1/B2 Project

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    CIAE signed Contract on Design,Commissioning and Technology Service for B1/B2 Project of Birine Reactor with CZEC in December,2015.The B1/B2 project which was won over by CZEC is PhaseⅠand PhaseⅡof an Algeria project which aimed to upgrade and rebuild Algeria Birine Nuclear Research Center.According to the contract with total fund amounting to 110million Yuan,CIAE will provide

  13. The structure, stability, and infrared spectrum of B 2N, B 2N +, B 2N -, BO, B 2O and B 2N 2.

    Science.gov (United States)

    Martin, J. M. L.; François, J. P.; Gijbels, R.

    1992-05-01

    The structure, infrared spectrum, and heat of formation of B 2N, B 2N -, BO, and B 2O have been studied ab initio. B 2N is very stable; B 2O even more so. B 2N, B 2N -, B 2O, and probably B 2N + have symmetric linear ground-state structures; for B 2O, an asymmetric linear structure lies about 12 kcal/mol above the ground state. B 2N +, B 2N - and B 2O have intense asymmetric stretching frequencies, predicted near 870, 1590 and 1400 cm -1, respectively. Our predicted harmonic frequencies and isotopic shifts for B 2O confirm the recent experimental identification by Andrews and Burkholder. Absorptions at 1889.5 and 1998.5 cm -1 in noble-gas trapped boron nitride vapor belong the BNB and BNBN ( 3Π), respectively; a tentative assignment of 882.5 cm -1 to BNB + is proposed. Total atomization energies Σ De (Σ D0) are computed (accuracy ±2 kcal/mol) as: BO 193.1 (190.4), B 2O 292.5 (288.7), B 2N 225.0 (250.3) kcal/mol. The ionization potential and electron affinity of B 2N are predicted to be 8.62±0.1 and 3.34±0.1 eV. The MP4-level additivity approximations involved in G1 theory results in errors on the order of 1 kcal/mol in the Σ De values.

  14. Assessing the Economic Cost of Landslide Damage in Low-Relief Regions: Case Study Evidence from the Flemish Ardennes (Belgium)

    Science.gov (United States)

    Vranken, L.; Van Turnhout, P.; Van Den Eeckhaut, M.; Vandekerckhove, L.; Vantilt, G.; Poesen, J.

    2012-04-01

    Several regions around the globe are at risk to incur damage from landslides. These landslides cause significant structural and functional damage to public and private buildings and infrastructure. Numerous studies investigated how natural factors and human activities control the (re-)activation of landslides. However, few studies have concentrated on a quantitative estimate of the overall damage caused by landslides at a regional scale. This study therefore starts with a quantitative economic assessment of the direct and indirect damage caused by landslides in the Flemish Ardennes (Belgium), a low-relief region (area=ca. 700 km2) susceptible to landslides. Based on focus interviews as well as on semi-structured interviews with homeowners, civil servants (e.g. from the technical services from the various towns), or with the owners and providers of lifelines such as electricity and sewage, we have quantitatively estimated the direct and indirect damage induced by landsliding and this for a 10 to 30 year period (depending on the type of infrastructure or buildings). Economic damage to public infrastructure and buildings was estimated for the entire region, while for private damage 10 cases with severe to small damage were quantified. For example, in the last 10 year, costs of road repair augmented to 814 560 €. Costs to repair damaged roads that have not yet been repaired, were estimated at 669 318 €. In the past 30 years, costs of measures to prevent road damage augmented to at least 14 872 380 €. More than 90% of this budget for preventive measures was spent 30 years ago, when an important freeway was damaged and had to be repaired. These preventive measures (building a grout wall and improving the drainage system) were effective as no further damage has been reported until present. To repair and prevent damage to waterworks and sewage systems, expenditures amounted to 551 044 € and this for the last 30 years. In the past 10 years, a new railway line

  15. Marketing Optimization for B2B Market

    OpenAIRE

    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)

    Science.gov (United States)

    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. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  18. 32 CFR 806b.2 - Basic guidelines.

    Science.gov (United States)

    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...

  19. 18 CFR 1b.2 - Scope.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Scope. 1b.2 Section 1b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.2 Scope. This part applies to...

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

    Structural and lattice dynamical properties of ReB2,RuB2,and OsB2 in the ReB2 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 preented. The obtained results are in good agreement with the available experimental and theoretical data.

  1. 12 CFR 264b.2 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Definitions. 264b.2 Section 264b.2 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM RULES... such. (c) Gift means a tangible or intangible present (other than a decoration) tendered by,...

  2. 18 CFR 3b.2 - Definitions.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE...

  3. Main: B2GMAUX28 [PLACE

    Lifescience Database Archive (English)

    Full Text Available B2GMAUX28 S000325 7-Sep-2000 (last modified) seki B2; DNase I protected sequence fo...und in the soybean (G.m.) auxin responsive gene, Aux28, promoter; Located between -310 and -301; Contains a ...TGACGACA sequence which is similar to TGACGT/C sequence found in Ocs, CaMV35S and histone H3 promoter; Contains as-1 motif; auxin; Aux28; as-1; soybean (Glycine max) CTTGTCGTCA ...

  4. Doping-induced superconductivity of ZrB2 and HfB2

    Science.gov (United States)

    Barbero, N.; Shiroka, T.; Delley, B.; Grant, T.; Machado, A. Â. J. Â. S.; Fisk, Z.; Ott, H.-R.; Mesot, J.

    2017-03-01

    Unlike the widely studied s -type two-gap superconductor MgB2, the chemically similar compounds ZrB2 and HfB2 do not superconduct above 1 K. Yet it has been shown that small amounts of self or extrinsic doping (in particular with vanadium), can induce superconductivity in these materials. Based on results of different macroscopic and microscopic measurements, including magnetometry, nuclear magnetic resonance (NMR), resistivity, and muon-spin rotation (μ+SR ), we present a comparative study of Zr0.96V0.04B2 and Hf0.97V0.03B2 . Their key magnetic and superconducting features are determined and the results are considered within the theoretical framework of multiband superconductivity proposed for MgB2. Detailed Fermi surface (FS) and electronic structure calculations reveal the difference between MgB2 and transition-metal diborides.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Superconductivity in MgB2

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In January of 2001 the superconductivity of the compound MgB2 with a critical temperature Tc of up to 39 K was discovered. This Tc is the highest in all intermetallic compound and alloy superconductors. MgB2 has a simple structure and its manufacturing capital cost is lower, therefore it could become a practical superconductor in the future. The recent progress is reviewed here which covers the progress in electronic structure, high Tc mechanism, superconducting parameters (Debye temperature, specific heat coefficient of electron, critical fields, coherent length, penetration depth, energy gap, critical current and relaxation rate of flux). Moreover the issue on power transmission is discussed.

  7. B2B Pioneer A Millionaire Maker

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China should soon see its largest group of instant millionaires after Jack Ma,Chief Executive Officer and Chairman of Alibaba Group,announced on July 27 that the China’s preeminent e-commerce company has initiated the listing of its B2B unit alibaba.com

  8. H Reactor

    Data.gov (United States)

    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...

  9. Electronic structure of MgB2

    Indian Academy of Sciences (India)

    P Modak; R S Rao; B K Godwal; S K Sikka

    2002-05-01

    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 experiment. We obtain the mass enhancement parameter by using our calculated (F) and the experimental specific heat data. The c is found to be 24.7 K.

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

    Science.gov (United States)

    Glowacki, B. A.; Nuttall, W. J.

    2008-02-01

    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 H2 (rather than electricity) is presented. Exploitation of produced hydrogen as a coolant and as a fuel is proposed in conjunction with MgB2 conductors for the tokomak magnets windings, and electrotechnical devices for Fusion Island's infrastructure. The benefits of using MgB2 over the Nb-based conductors during construction, operation and decommissioning of the Fusion Island Reactor are presented. The comparison of Nb3Sn strands for ITER fusion magnet with newly developed high field composite MgB2 PIT conductors has shown that at 14 Tesla MgB2 possesses better properties than any of the Nb3Sn conductors produced. In this paper the potential of MgB2 conductors is examined for tokamaks of both the conventional ITER type and a Spherical Tokamak geometry. In each case MgB2 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 MgB2 conductors for Fusion Island are also considered.

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

    Science.gov (United States)

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-224 B-2 Extremely High Frequency SATCOM and Computer Increment 1 (B-2 EHF Inc 1) As of FY...10 Track to Budget 11 Cost and Funding 13 Low Rate Initial Production 19 Foreign Military Sales 20 Nuclear Costs 20 Unit Cost...Document CLIN - Contract Line Item Number CPD - Capability Production Document CY - Calendar Year DAB - Defense Acquisition Board DAE - Defense

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

    Science.gov (United States)

    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.

  13. Synthesis of MgB2 at Low Temperature and Autogenous Pressure

    Directory of Open Access Journals (Sweden)

    Ian D. R. Mackinnon

    2014-05-01

    Full Text Available High quality, micron-sized interpenetrating grains of MgB2, with high density, are produced at low temperatures (~420 °C < T < ~500 °C under autogenous pressure by pre-mixing Mg powder and NaBH4 and heating in an Inconel 601 alloy reactor for 5–15 h. Optimum production of MgB2, with yields greater than 75%, occurs for autogenous pressure in the range 1.0 MPa to 2.0 MPa, with the reactor at ~500 °C. Autogenous pressure is induced by the decomposition of NaBH4 in the presence of Mg and/or other Mg-based compounds. The morphology, transition temperature and magnetic properties of MgB2 are dependent on the heating regime. Significant improvement in physical properties accrues when the reactor temperature is held at 250 °C for >20 min prior to a hold at 500 °C.

  14. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. To be or not B2B?

    CERN Document Server

    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...

  16. Reactor safeguards

    CERN Document Server

    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

  17. Reactor operation

    CERN Document Server

    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

  18. ONLINE ACQUISITIONS IN B2B MODEL

    Directory of Open Access Journals (Sweden)

    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.

  19. Producing composite materials based on ZrB2, ZrB2-SiC

    Science.gov (United States)

    Mirovoi, Yu A.; Burlachenko, A. G.; Buyakova, S. P.; Sevostiyanova, I. N.; Kulkov, S. N.

    2016-11-01

    The effect of mechanical treatment by planetary ball milling on the properties of hot pressed ZrB2 - SiC ceramics was studied. It has been shown that material densification after mechanical treatment is finished at initial stages of sintering process. Addition of SiC causes a substantial increase in density of the sample to 99% of the theoretical powder containing 20% of silicon carbide, in comparison with samples ZrB2 density not exceeding 76%. It has been shown that all defects which were accumulated during mechanical treatment anneal in hot pressure process and there are no any changes of CDD values in sintered ceramics.

  20. Reactor Neutrinos

    OpenAIRE

    Soo-Bong Kim; Thierry Lasserre; Yifang Wang

    2013-01-01

    We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very ...

  1. Improved Superconducting properties in the Mg(11)B2 low activation superconductor prepared by low-temperature sintering.

    Science.gov (United States)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M; Somer, M

    2016-05-05

    Mg(11)B2 has a great application prospect in the superconducting coils for fusion reactor as the "low activation superconductors". The un-doped Mg(11)B2 and Cu-doped Mg(11)B2 bulks using (11)B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg(11)B2 low activation superconductors exhibit better Jc performance than all of other Mg(11)B2 samples reported in previous studies. As for Cu doped Mg(11)B2, minor Cu addition can obviously improve the Mg(11)B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg(11)B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields.

  2. Improved Superconducting properties in the Mg11B2 low activation superconductor prepared by low-temperature sintering

    Science.gov (United States)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M.; Somer, M.

    2016-05-01

    Mg11B2 has a great application prospect in the superconducting coils for fusion reactor as the “low activation superconductors”. The un-doped Mg11B2 and Cu-doped Mg11B2 bulks using 11B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg11B2 low activation superconductors exhibit better Jc performance than all of other Mg11B2 samples reported in previous studies. As for Cu doped Mg11B2, minor Cu addition can obviously improve the Mg11B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg11B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields.

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

    Science.gov (United States)

    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.

  4. MgB2 tunnel junctions and SQUIDs

    NARCIS (Netherlands)

    Brinkman, A.; Rowell, J.M.

    2007-01-01

    Recent advances in the realization and understanding of MgB2 tunnel junctions and SQUIDs are surveyed. High quality MgB2 junctions with suitable tunnel barriers have been realized based on both oriented and epitaxial thin MgB2 films. Multiband transport properties, such as the existence of two energ

  5. 32 CFR 242b.2 - Meetings of the Board.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Meetings of the Board. 242b.2 Section 242b.2... THE HEALTH SCIENCES § 242b.2 Meetings of the Board. (a) Regular meetings. (1) The Board shall hold at... determined by the Board, meetings shall be held at the offices of the University, 4301 Jones Bridge...

  6. TRUST IN B2B E-MARKETPLACES

    Directory of Open Access Journals (Sweden)

    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.

  7. Mechanical properties and microstructure of TiB2 ceramic influenced by ZrB2 additive

    Institute of Scientific and Technical Information of China (English)

    王皓; 傅正义; 辜萍; 王为民; 袁润章

    2002-01-01

    Since some transition metal diborides have the same crystal structure with TiB2, which can react with TiB2 to form solid solution by adequate technique. With ZrB2 used as additive, the TiB2-ZrB2 solid solution was prepared by hot pressing. The effects of additive content on mechanical properties of composite were investigated. The microstructure analyzing were employed by EPMA, SEM and TEM. It is shown that TiB2 can partly form solid solution with ZrB2 and redound to gain uniform grains, which h results in the increase of mechanical properties.

  8. Multifunctional reactors

    NARCIS (Netherlands)

    Westerterp, K.R.

    1992-01-01

    Multifunctional reactors are single pieces of equipment in which, besides the reaction, other functions are carried out simultaneously. The other functions can be a heat, mass or momentum transfer operation and even another reaction. Multifunctional reactors are not new, but they have received much

  9. Substitution of Mn for Mg in MgB_2*

    Science.gov (United States)

    Fitzpatrick, Michael D.; Johnston, David C.; Miller, Lance L.; Hill, Julienne M.

    2002-03-01

    The study of solid solutions in which the Mg in MgB2 is partially replaced by magnetic 3d or 4f atoms can potentially reveal important information on the superconducting state of MgB_2. As an end-member of the hypothetical Mg_1-xMn_xB2 system, MnB2 is isostructural with MgB2 and is an antiferromagnet below TN = 760 K which becomes canted at 157 K. A previous study by Moritomo et al.[1] examined the structure and properties of multi-phase samples with 0.01J. Phys. Soc. Japan b70, 1889 (2001).; “Effects of transition metal doping in MgB2 superconductor", Y. Moritomo at al. arXiv:cond-mat/0104568.

  10. Harnessing marketing automation for B2B content marketing

    OpenAIRE

    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...

  11. Boron isotope effect in superconducting MgB2.

    Science.gov (United States)

    Bud'ko, S L; Lapertot, G; Petrovic, C; Cunningham, C E; Anderson, N; Canfield, P C

    2001-02-26

    We report the preparation method of and boron isotope effect for MgB2, a new binary intermetallic superconductor with a remarkably high superconducting transition temperature T(c)(10B) = 40.2 K. Measurements of both temperature dependent magnetization and specific heat reveal a 1.0 K shift in T(c) between Mg11B2 and Mg10B2. Whereas such a high transition temperature might imply exotic coupling mechanisms, the boron isotope effect in MgB2 is consistent with the material being a phonon-mediated BCS superconductor.

  12. RAZVOJ B2B PORTALA ZA POTREBE ELEKTRONSKEGA POSLOVANJA

    OpenAIRE

    Slanič, Matej

    2011-01-01

    V diplomski nalogi opredelimo vlogo B2B portalov in pomen elektronskega poslovanja. B2B portale smo razvrstili glede na različne kriterije in predstavili različne modele trgovanja na njih. Velik del pozornosti smo posvetili tudi strateškemu načrtovanju B2B poslovanja in vključevanju podjetij na B2B portale, dotaknili pa smo se tudi vizije elektronskega poslovanja. Osrednji del naloge obsega predstavitev gradnje specifičnega portala Bbuines.com ter z njo povezane oblikovne in tehnološke rešitv...

  13. Reactor vessel

    OpenAIRE

    Makkee, M.; Kapteijn, F.; Moulijn, J.A

    1999-01-01

    A reactor vessel (1) comprises a reactor body (2) through which channels (3) are provided whose surface comprises longitudinal inwardly directed parts (4) and is provided with a catalyst (6), as well as buffer bodies (8, 12) connected to the channels (3) on both sides of the reactor body (2) and comprising connections for supplying (9, 10, 11) and discharging (13, 14, 15) via the channels (3) gases and/or liquids entering into a reaction with each other and substances formed upon this reactio...

  14. NUCLEAR REACTOR

    Science.gov (United States)

    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.

  15. Reactor Neutrinos

    Directory of Open Access Journals (Sweden)

    Soo-Bong Kim

    2013-01-01

    Full Text Available We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angle θ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.

  16. Chemical Reactors.

    Science.gov (United States)

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  17. Reactor Neutrinos

    OpenAIRE

    Lasserre, T.; Sobel, H.W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrin...

  18. Multiband model for tunneling in MgB2 junctions

    NARCIS (Netherlands)

    Brinkman, A.; Golubov, A.A.; Rogalla, H.; 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 temperat

  19. B2B myynnin johtaminen ravintola-alalla

    OpenAIRE

    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...

  20. Pulse Plating of Copper-ZrB2 Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    Dongming GUO; Min ZHANG; Zhuji JIN; Renke KANG

    2006-01-01

    Copper-zirconium diboride (ZrB2) composite coatings were fabricated using pulse plating technique to acquire a new type of EDM (electro-discharge machining) electrode material. The effects of pulse parameters, i.e., the average current density, the frequency and the duty cycle, on the incorporation of ZrB2 particles in the copper matrix were investigated. The amountof codeposited ZrB2 particles had a maximum at average current density of 3 A/dm2 and increased with decreasing duty cycle as well as current frequency of the pulse current used for deposition. The hardness of the coatings increased with increasing ZrB2 percentage, whereas the incorporation of ZrB2 particles had little effect on the resistivity of the composites.

  1. Preparation of MgB2 Superconducting Materials%MgB2超导材料的制备

    Institute of Scientific and Technical Information of China (English)

    王醒东

    2014-01-01

    二硼化镁(MgB2)是重要的超导材料,在超导磁体等领域有着潜在的应用.本文介绍了MgB2超导块材、带材及薄膜,重点介绍了制备MgB2超导带材的粉末套管法以及制备MgB2超导薄膜的电子束蒸发法、共蒸发法和溅射法,指出了MgB2超导材料未来的发展方向.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    High-pressure X-ray diffraction in ScB2, TiB2, YB4 and HoB4 powders and single crystals has been studied using synchrotron radiation as well as conventional X-rays. The experimental results are supported by calculations using density functional theory. ScB2, YB4 and HoB4 are hard materials (bulk...... modulus 180-200GPa), while TiB2 may be classified as superhard (bulk modulus about 260GPa). We report here first experimental and theoretical determinations of the bulk modulus for HoB4 (195(5) and 198.2GPa, respectively), and first experimental values of the bulk modulus for ScB2 (196(2)GPa) and YB4 (185...

  3. Fine-Filament MgB2 Superconductor Wire

    Science.gov (United States)

    Cantu, Sherrie

    2015-01-01

    Hyper Tech Research, Inc., has developed fine-filament magnesium diboride (MgB2) superconductor wire for motors and generators used in turboelectric aircraft propulsion systems. In Phase I of the project, Hyper Tech demonstrated that MgB2 multifilament wires (MgB2 rotor coil packs for a superconducting generator. The ultimate goal is to enable low-cost, round, lightweight, low-AC-loss superconductors for motor and generator stator coils operating at 25 K in next-generation turboelectric aircraft propulsion systems.

  4. Ultrasonic Properties of the MgB2 Superconductor

    Institute of Scientific and Technical Information of China (English)

    YU Ri-Cheng; JIN Chang-Qing; LI Shao-Chun; WANG Ru-Ju; LI Feng-Ying; LIU Zhen-Xing; ZHU Jia-Lin

    2001-01-01

    The sound velocities of longitudinal and shear waves are measured on a polycrystalline MgB2 superconductor with Tc of 39 K. The specimen used in the experiments is pressed and heated using the MgB2 powder. The elastic moduli, Debye temperature and specific heat at room temperature are obtained based on sound velocity data. The results indicate that the velocities are much higher than those in the usual materials, while elastic constants remain reasonably soft, which may be due to the high transition temperature of the MgB2 superconductor.

  5. B2B virksomheders brug af sociale medier

    OpenAIRE

    Persdatter Gotfredsen, Karoline

    2016-01-01

    Purpose: The aim of this master thesis is to explore how B2B firms perceive their own usage of social media to establish and strengthen successful relational exchanges. Approach: In-depth interviews were carried out with three key informants responsible for social media marketing at large B2B firms. The findings from the three interviews were then analysed case-by-case and finally a cross case analysis was conducted. Findings: In relation to the market B2B firms mainly see social media...

  6. B2B营销的权威

    Institute of Scientific and Technical Information of China (English)

    陈荣

    2006-01-01

    现在很流行的一个词就是B2B营销,那么到底什么叫B2B营销呢?雷·赖特所著的《组织间营销》(英文全名Business—to—Business Marketing:AStep-by-Step Guide)可以回答你的问题,它可谓是全面了解B2B营销所涉及的各个层面的权威书籍。

  7. Bending strain tolerance of MgB2 superconducting wires

    Science.gov (United States)

    Kováč, P.; Hušek, I.; Melišek, T.; Kulich, M.; Kopera, L.

    2016-04-01

    This work describes the strain tolerance of MgB2 superconductors subjected to variable bending stresses. Bending of MgB2 wire was done at room temperature in different modes: (i) direct bending of straight annealed samples to variable diameters and by (ii) indirect bending by straightening of bent and annealed samples. I c-bending strain characteristics of samples made by in situ PIT and by the internal magnesium diffusion (IMD) process were measured at 4.2 K. The results show a good agreement between the direct and indirect bending mode, which allows easier estimation of limits important for the winding process of MgB2 superconductors with brittle filaments. A comparison of MgB2 wires made by in situ PIT and IMD processes showed improved strain tolerance for IMD due to better grain connectivity the low annealing temperature, which does not appear to reduce the mechanical strength of sheath material.

  8. 26 CFR 301.7701(b)-2 - Closer connection exception.

    Science.gov (United States)

    2010-04-01

    ...) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Definitions § 301.7701(b)-2 Closer connection...) Tax home—(1) Definition. For purposes of section 7701 (b) and the regulations under that section,...

  9. Preparation and characterization of MgB2 superconductor

    Indian Academy of Sciences (India)

    Shashwati Sen; D K Aswal; Ajay Singh; T V Chandrasekhar Rao; K P Muthe; J C Vyas; L C Gupta; S K Gupta; V C Sahni

    2002-05-01

    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 determined using magnetization data. The current–voltage characteristics recorded under an applied magnetic field revealed the existence of vortex glass transition. The surface analysis using X-ray photoelectron spectroscopy shows that MgB2 is sensitive to atmospheric degradation.

  10. Attempts at doping indium in MgB2

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2016-01-01

    Indium (In) doped MgB2 polycrystalline samples were prepared by solid-liquid phase reaction in Ar. After reaction at 800 °C, less than 1 at.% Mg was replaced by In in the MgB2 phase, without significant influence on its lattice parameters and only a slight decrease of its superconducting transition...... in both the doped and undoped samples....

  11. Branding of electricity in B2B markets

    OpenAIRE

    Rolanda Simenaite 1986

    2013-01-01

    Branding has gained an important role in the B2B (business-to-business) market. Liberation of the energy markets in recent years has increased competition and branding could create a competitive advantage. This thesis analyzes the branding of electricity in a business-to-business context. In depth, this thesis explores the supplier of electricity brand importance for business customers in both Icelandic and Lithuanian B2B markets. The focus of the thesis is to research how much brands matter ...

  12. Phonon dispersion and electron-phonon coupling in MgB2 and AlB2.

    Science.gov (United States)

    Bohnen, K P; Heid, R; Renker, B

    2001-06-18

    We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the superconductor MgB2 and the isostructural AlB2 within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. Complete phonon dispersion curves and Eliashberg functions alpha2F are calculated for both systems. The main differences are related to high frequency in-plane boron vibrations, which are strongly softened in MgB2 and exhibit an exceptionally strong electron-phonon coupling. We also report on Raman measurements, which support the theoretical findings. Implications for the superconducting transition temperature are briefly discussed.

  13. Improvement in the transport critical current density and microstructure of isotopic Mg11B2 monofilament wires by optimizing the sintering temperature

    Science.gov (United States)

    Qiu, Wenbin; Jie, Hyunseock; Patel, Dipak; Lu, Yao; Luzin, Vladimir; Devred, Arnaud; Somer, Mehmet; Shahabuddin, Mohammed; Kim, Jung Ho; Ma, Zongqing; Dou, Shi Xue; Hossain, Md. Shahriar Al

    2016-11-01

    Superconducting wires are widely used in fabricating magnetic coils in fusion reactors. In consideration of the stability of 11B against neutron irradiation and lower induced radio-activation properties, MgB2 superconductor with 11B serving as boron source is an alternative candidate to be used in fusion reactor with severe irradiation environment. In present work, a batch of monofilament isotopic Mg11B2 wires with amorphous 11B powder as precursor were fabricated using powder-in-tube (PIT) process at different sintering temperature, and the evolution of their microstructure and corresponding superconducting properties was systemically investigated. Accordingly, the best transport critical current density (Jc) = 2 × 104 A/cm2 was obtained at 4.2 K and 5 T, which is even comparable to multi-filament Mg11B2 isotope wires reported in other work. Surprisingly, transport Jc vanished in our wire which was heat-treated at excessively high temperature (800 °C). Combined with microstructure observation, it was found that lots of big interconnected microcracks and voids that can isolate the MgB2 grains formed in this whole sample, resulting in significant deterioration in inter-grain connectivity. The results can be a constructive guide in fabricating Mg11B2 wires to be used as magnet coils in fusion reactor systems such as ITER-type tokamak magnet.

  14. Superconductivity in dense MgB2 wires.

    Science.gov (United States)

    Canfield, P C; Finnemore, D K; Bud'ko, S L; Ostenson, J E; Lapertot, G; Cunningham, C E; Petrovic, C

    2001-03-12

    MgB2 becomes superconducting just below 40 K. Whereas porous polycrystalline samples of MgB2 can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB2 can be prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 microm, are better than 80% dense, and manifest the full chi = -1/4pi shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB2 is a highly conducting metal in the normal state with rho(40 K) = 0.38 microOmega cm. By using this value, an electronic mean-free path, l approximately 600 A can be estimated, indicating that MgB2 wires are well within the clean limit. Tc, Hc2(T), and Jc data indicate that MgB2 manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet.

  15. Mechanical and thermal properties of bulk ZrB2

    Science.gov (United States)

    Nakamori, Fumihiro; Ohishi, Yuji; Muta, Hiroaki; Kurosaki, Ken; Fukumoto, Ken-ichi; Yamanaka, Shinsuke

    2015-12-01

    ZrB2 appears to have formed in the fuel debris at the Fukushima Daiichi nuclear disaster site, through the reaction between Zircaloy cladding materials and the control rod material B4C. Since ZrB2 has a high melting point of 3518 K, the ceramic has been widely studied as a heat-resistant material. Although various studies on the thermochemical and thermophysical properties have been performed for ZrB2, significant differences exist in the data, possibly due to impurities or the porosity within the studied samples. In the present study, we have prepared a ZrB2 bulk sample with 93.1% theoretical density by sintering ZrB2 powder. On this sample, we have comprehensively examined the thermal and mechanical properties of ZrB2 by the measurement of specific heat, ultrasonic sound velocities, thermal diffusivity, and thermal expansion. Vickers hardness and fracture toughness were also measured and found to be 13-23 GPa and 1.8-2.8 MPa m0.5, respectively. The relationships between these properties were carefully examined in the present study.

  16. Sonochemical Reactors.

    Science.gov (United States)

    Gogate, Parag R; Patil, Pankaj N

    2016-10-01

    Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation.

  17. B-B bond activation and NHC ring-expansion reactions of diboron(4) compounds, and accurate molecular structures of B2(NMe2)4, B2eg2, B2neop2 and B2pin2.

    Science.gov (United States)

    Eck, Martin; Würtemberger-Pietsch, Sabrina; Eichhorn, Antonius; Berthel, Johannes H J; Bertermann, Rüdiger; Paul, Ursula S D; Schneider, Heidi; Friedrich, Alexandra; Kleeberg, Christian; Radius, Udo; Marder, Todd B

    2017-03-14

    In this detailed study we report on the structures of the widely employed diboron(4) compounds bis(pinacolato)diboron (B2pin2) and bis(neopentyl glycolato)diboron (B2neop2), as well as bis(ethylene glycolato)diboron (B2eg2) and tetrakis(dimethylamino)diboron (B2(NMe2)4), and their reactivity, along with that of bis(catecholato)diboron (B2cat2) with backbone saturated and backbone unsaturared N-heterocyclic carbenes (NHCs) of different steric demand. Depending on the nature of the diboron(4) compound and the NHC used, Lewis-acid/Lewis-base adducts or NHC ring-expansion products stemming from B-B and C-N bond activation have been observed. The corresponding NHC adducts and NHC ring-expanded products were isolated and characterised via solid-state and solution NMR spectroscopy and X-ray diffraction. In general, we observed B-B bond and C-N bond activation at low temperature for B2eg2, at room temperature for B2neop2 and at higher temperature for B2cat2. The reactivity strongly depends on steric effects of the NHCs and the diboron(4) compounds, as well as on the corresponding Lewis-basicity and Lewis-acidity. Our results provide profound insight into the chemistry of these diboron(4) reagents with the nowadays ubiquitous NHCs, the stability of the corresponding NHC adducts and on B-B bond activation using Lewis-bases in general. We demonstrate that B-B bond activation may be triggered even at temperatures as low as -40 °C to -30 °C without any metal species involved. For example, the reactions of B2eg2 with sterically less demanding NHCs such as Me2Im(Me) and iPr2Im in solution led to the corresponding ring-expanded products at low temperatures. Furthermore, boronium [L2B(OR)2](+) and borenium [LB(OR)2](+) cations have been observed from the reaction of the bis-borate B2eg3 with the NHCs iPr2Im and Me2Im(Me), which led to the conclusion that the activation of bis-borates with NHCs (or Lewis-bases in general) might be a facile and simple route to access such species.

  18. Mechanical Spectroscopy of MgB2 Containing Sic / Spektroskopia Mechaniczna MgB2 Zawierającego Sic

    Directory of Open Access Journals (Sweden)

    Silva M.R.

    2015-12-01

    Full Text Available The compound magnesium diboride (MgB2 has been well-known since the 1950s; however, its superconducting properties were unknown. Intrinsic characteristics of MgB2 make this material a promising candidate for technological applications, although the low value of the irreversibility field and the decrease in critical current density with the increase in the magnetic field considerably reduce its utility. The present work aimed to study the effect of carbon-based doping on anelastic properties of MgB2 as measured by mechanical spectroscopy. The samples were prepared by using the powder-intube method. The samples were made with 5, 7.5, and 10 wt.% of silicon carbide (SiC. The results reveal complex mechanical loss spectra caused by the interaction between point defects and surface defects in the crystalline lattice of MgB2.

  19. Possible antiferromagnetic interactions in NdRh 3B 2 and CeRh 3B 2

    Science.gov (United States)

    Takeda, K.; Kohara, T.; Kitaoka, Y.; Asayama, K.

    1987-06-01

    The magnetic phase transition and spin arrangement in the ordered phase of NdRh3B2 and CeRh3B2 have been studied by measurements of magnetic susceptibility and heat capacity of the isostructural compounds RRh3B2 ( R: La, Ce, Nd, Gd). The existence of small antiferromagnetic interactions between R ions ( R = Nd, Ce) on the neighbouring ferromagnetic chains along the c-axis has been suggested. This model gives another aspect to explain the origin of the anomalous magnetism of CeRh3B2 such as the small value of magnetic moment in the ordered state and the curious behaviour of susceptibility. The magnitude of the effective moment of Ce has been estimated for the consumption of magnetic entropy of the Ce compound.

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

    Science.gov (United States)

    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.

  1. Non-resonant microwave absorption studies of superconducting MgB2 and MgB2 + MgO

    Indian Academy of Sciences (India)

    Janhavi P Joshi; Subhasis Sarangi; A K Sood; Dilip Pal; S V Bhat

    2002-02-01

    Non-resonant microwave absorption (NRMA) studies of superconducting MgB2 and a sample containing ∼ 10% by weight of MgO in MgB2 are reported. The NRMA results indicate near absence of intergranular weak links in the pure MgB2 sample. A linear temperature dependence of the lower critical field c1 is observed indicating a non- wave superconductivity. However, the phase reversal of the NRMA signal which could suggest wave symmetry is also not observed. In the MgB2 + MgO sample, much larger low field dependent absorption is observed indicating the presence of intergranular weak links. The hysteretic behavior of NRMA is compared and contrasted in the two samples. In the pure MgB2 sample, a large hysteresis is observed between the forward and the reverse scans of the magnetic field indicating strong pinning of flux lines. This hysteresis saturates a few degrees below c while in the MgB2 + MgO sample, a much slower increase of hysteresis with decreasing temperature is observed, a signature of weaker pinning.

  2. EBSD analysis of MgB2 bulk superconductors

    Science.gov (United States)

    Koblischka-Veneva, A.; Koblischka, M. R.; Schmauch, J.; Inoue, K.; Muralidhar, M.; Berger, K.; Noudem, J.

    2016-04-01

    The grain orientation, the texture and the grain boundary misorientations are important parameters for the understanding of the magnetic properties of the bulk MgB2 samples intended for super-magnet applications. Such data can be provided by electron backscatter diffraction (EBSD) analysis. However, as the grain size (GS) of the MgB2 bulks is preferably in the 100-200 nm range, the common EBSD technique working in reflection operates properly only on highly dense samples. In order to achieve a reasonably good Kikuchi pattern quality on all samples, we apply here the newly developed transmission EBSD (t-EBSD) technique to several bulk MgB2 samples. This method requires the preparation of TEM slices by means of focused ion-beam milling, which are then analyzed within the SEM, operating with a specific sample holder. We present several EBSD mappings of samples prepared with different techniques and at various reaction temperatures.

  3. MgB2 superconducting wires basics and applications

    CERN Document Server

    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. Applying conceptual design to B2B sales negotiations

    DEFF Research Database (Denmark)

    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......, service, configuration and customisation of the products in their company as well as to develop an apposite understanding of the key values and characteristics of the client organisation. Based on a design-ethnographical study of real sales practice in lift truck business the paper draws parallels between...

  5. Superconducting properties of MgB2 from first principles.

    Science.gov (United States)

    Floris, A; Profeta, G; Lathiotakis, N N; Lüders, M; Marques, M A L; Franchini, C; Gross, E K U; Continenza, A; Massidda, S

    2005-01-28

    Solid MgB(2) has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first nontrivial application of a novel density-functional-type theory for superconductors, recently proposed by the authors. Without invoking any adjustable parameters, we obtain the transition temperature, the gaps, and the specific heat of MgB(2) in very good agreement with experiment. Moreover, our calculations show how the Coulomb interaction acts differently on sigma and pi states, thereby stabilizing the observed superconducting phase.

  6. Superconductivity of metallic boron in MgB2.

    Science.gov (United States)

    Kortus, J; Mazin, I I; Belashchenko, K D; Antropov, V P; Boyer, L L

    2001-05-14

    Boron in MgB2 forms stacks of honeycomb layers with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with an ionic component and considerable metallic density of states yield a sizable electron-phonon coupling. Together with high phonon frequencies, which we estimate via zone-center frozen phonon calculations to be between 300 and 700 cm(-1), this produces a high critical temperature, consistent with recent experiments. Thus MgB2 can be viewed as an analog of the long sought, but still hypothetical, superconducting metallic hydrogen.

  7. Is Lithium Sulfide a MgB2-like Superconductor?

    OpenAIRE

    Isikaku-Ironkwe, O. P.

    2012-01-01

    Lithium Sulfide, Li2S, is an anti-fluorite semiconductor with a band-gap of 3.865 eV. It also has exactly the same valence electron count, Ne, and atomic number, Z, as magnesium diboride, MgB2. Both have almost the same formula weight. This qualifies Li2S as a magnesium-diboride like material. Li2S passes the same computational material specific test for superconductivity as MgB2. Using our recently developed symmetry rules for searching for superconductors, we predict that Li2S, with electro...

  8. Risk Analysis and Consumer Protection in B2C Transactions

    Institute of Scientific and Technical Information of China (English)

    YANG Jian-zheng; SHI Qi-liang; Gary Millar; Ruhul A. Sarker

    2005-01-01

    Recent studies have shown that the perceived lack of security is a major obstacle to the wider acceptance of e-commerce. To overcome this barrier, businesses need to implement comprehensive consumer protection systems that protect consumers during every stage of the purchasing process. This paper used the consumer behaviour model as the basis for analysing risks in Bussiness-to-Consumer (B2C) transactions. Four categories of risks were identified: information, agreement, payment and delivery risk. By combining these risk categories with the three dimensions of management, technology and legislation, a comprehensive B2C consumer protection framework is developed.

  9. Isostructural Transition of MgB2 Under High Pressure

    Institute of Scientific and Technical Information of China (English)

    SUN Li-Ling; WU Qi; ZHAN Zai-Ji; WANG Wen-Kui; WANG Wen-Kui; T.Kikegawa

    2001-01-01

    The high-pressure behaviour of the superconductor MgB2 with a hexagonal structure has been investigated by the in situ synchrotron radiation x-ray diffraction method under pressures up to 42.2 GPa in a diamond anvil cell. An abrupt decrease of about 7% in the unit cell volume of this material occurs in the pressure range of 26.3-30.2 GPa. A split of the Raman spectrum was also observed. The jump of the compression curve and Raman spectrum are ascribed to an isostructural transition in MgB2 at a pressure of 30.2 GPa.

  10. Customized E-Learning for B2B Companies

    Directory of Open Access Journals (Sweden)

    Tim Thomasma

    2014-06-01

    Full Text Available Business-to-Business (B2B companies have customers that are primarily other corporations. These companies have unique problems in workplace training. They must train their customers and their customers’ employees. A B2B company may operate with only a few dozen employees, but they may need to help thousands of customers learn how to make best use of their product or service. Discussions with industry executives suggest an ideal training solution might include a number of features that are reviewed in this paper.

  11. Multiband model for penetration depth in MgB2

    NARCIS (Netherlands)

    Golubov, A.A.; Brinkman, A.; Dolgov, O.V.; Kortus, J.; Jepsen, O.

    2002-01-01

    The results of first-principles calculations of the electronic structure and the electron-phonon interaction in MgB2 are used to study theoretically the temperature dependence and anisotropy of the magnetic-field penetration depth. The effects of impurity scattering are essential for a proper descri

  12. Itinerant magnetism in CeRh3B2

    DEFF Research Database (Denmark)

    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...

  13. Investigation of TaC–TaB2 ceramic composites

    Indian Academy of Sciences (India)

    Behzad Mehdikhani; Gholam Hossein Borhani; Saeed Reza Bakhshi; Hamid Reza Baharvandi

    2016-02-01

    The TaC–TaB2 composition was sintered by spark plasma (SPS) at 1900–2100°C and applied pressure of 30 MPa. TaC and 2–3 wt% B4C were used as starting powders. Densification process, phase evolution, microstructure and the mechanical properties of the composites were investigated. The results indicated that the TaC–TaB2 composition could be SPS to 97% of theoretical density in 10 min at 2100°C. Addition of B4C leads to an increase in the density sample from 76 to 97%. B4C nano-powder resists grain growth even at high temperature 2100°C. The formation of TaB2/carbon at TaC grain boundaries helps in pinning the grain boundary and inhibiting grain growth. The phase formation was associated with carbon and boron diffusion from the starting particles B4C to form TaB2 phases. TaC grain sizes decreased with increase in B4C concentration. Samples with 2.0 wt% B4C composition had highest flexure strength up to 520 MPa. The effect of B4C addition on hardness measured by microhardness has been studied. Hardness of samples containing 3.0 wt% B4C was 16.99 GPa.

  14. Structural, electronic and magnetic properties of MnB2

    Indian Academy of Sciences (India)

    R Masrour; E K Hlil; M Hamedoun; A Benyoussef; O Mounkachi; H El Moussaoui

    2015-08-01

    The self-consistent ab-initio calculations, based on density functional theory approach and using the full potential linear augmented plane wave method, are performed to investigate both electronic and magnetic properties of the MnB2 compounds. Polarized spin and spin–orbit coupling are included in calculations within the framework of the ferromagnetic state between two adjacent Mn atoms. Magnetic moment considered to lie along the (001) axes are computed. The antiferromagnetic and ferromagnetic energies of MnB2 systems are obtained. Obtained data from ab-initio calculations are used as input for the high-temperature series expansions (HTSEs) calculations to compute other magnetic parameters. The exchange interactions between the magnetic atoms Mn–Mn in MnB2 are established by using the mean field theory. The HTSEs of the magnetic susceptibility with the magnetic moments in MnB2 (Mn) through Ising model is given. The critical temperature C (K) is obtained by HTSEs applied to the magnetic susceptibility series combined with the Padé approximant method. The critical exponent associated with the magnetic susceptibility is deduced as well.

  15. Supporting B2B Business Documents in XML Web Services

    Institute of Scientific and Technical Information of China (English)

    KIM Hyoungdo

    2004-01-01

    While XML web services become recognized as a solution to business-to-business transactions, there are many problems that should be solved. For example, it is not easy to manipulate business documents of existing standards such as RosettaNet and UN/EDIFACT EDI, traditionally regarded as an important resource for managing B2B relationships. As a starting point for the complete implementation of B2B web services, this paper deals with how to support B2B business documents in XML web services. In the first phase, basic requirements for driving XML web services by business documents are introduced. As a solution, this paper presents how to express B2B business documents in WSDL, a core standard for XML web services. This kind of approach facilitates the reuse of existing business documents and enhances interoperability between implemented web services. Furthermore, it suggests how to link with other conceptual modeling frameworks such as ebXML/UMM, built on a rich heritage of electronic business experience.

  16. Marketing-sales interface configurations in B2B firms

    NARCIS (Netherlands)

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

    2010-01-01

    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 Net

  17. Superconductivity in MgB2: Clean or Dirty?

    NARCIS (Netherlands)

    Mazin, I.I.; Andersen, O.K.; Jepsen, O.; Dolgov, O.V.; Kortus, J.; Golubov, A.A.; Kuz'menko, A.B.; Marel, van der D.

    2002-01-01

    A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB2. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and, presumably, a strong correlation between the critical temperature and

  18. Oxidation of ZrB2 and ZrB2-SiC Ceramics With Tungsten Additions (Preprint)

    Science.gov (United States)

    2009-02-01

    Electrochemical Society . PAO Case Number: 88 ABW-2008-1143; Clearance Date: 26 Nov 2008. Paper contains color. 14. ABSTRACT The effect of tungsten...18 For submission to proceedings of the 214th meeting of the Electrochemical Society Oxidation of ZrB2 and ZrB2-SiC Ceramics with Tungsten...TaSi2 that form a protective SiO2-rich oxide scale at temperatures 1 For submission to proceedings of the 214th meeting of the Electrochemical Society above

  19. Dynamics of the formation and loss of boron atoms in a H2/B2H6 microwave plasma

    Science.gov (United States)

    Duluard, C. Y.; Aubert, X.; Sadeghi, N.; Gicquel, A.

    2016-09-01

    For further improvements in doped-diamond deposition technology, an understanding of the complex chemistry in H2/CH4/B2H6 plasmas is of general importance. In this context, a H2/B2H6 plasma ignited by microwave power in a near resonant cavity at high pressure (100-200 mbar) is studied to measure the B-atom density in the ground state. The discharge is ignited in the gas mixture (0-135 ppm B2H6 in H2) by a 2.45 GHz microwave generator, leading to the formation of a hemispheric plasma core, surrounded by a faint discharge halo filling the remaining reactor volume. Measurements with both laser induced fluorescence and resonant absoption with a boron hollow cathode lamp indicate that the B-atom density is higher in the halo than in the plasma core. When the absorption line-of-sight is positioned in the halo, the absorption is so strong that the upper detection limit is reached. To understand the mechanisms of creation and loss of boron atoms, time-resolved absorption measurements have been carried out in a pulsed plasma regime (10 Hz, duty cycle 50%). The study focuses on the influence of the total pressure, the partial pressure of B2H6, as well as the source power, on the growth and decay rates of boron atoms when the plasma is turned off.

  20. Sintering process and critical current density of low activation Mg11B2 superconductors from low temperature to high temperature

    Science.gov (United States)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, Md; Somer, M.

    2016-08-01

    As the "low activation" superconductor, Mg11B2 has a potential application in superconducting coils for fusion reactor. In present work, the sintering process and critical current density of low activation Mg11B2 superconductors were systemically studied from low temperature to high temperature. It was found that the Jc and Hirr values of Mg11B2 bulks in present work are both obviously higher than that of those samples prepared in previous studies. Furthermore, the low-temperature sintered samples exhibit better Jc performance at high fields than the high-temperature sintered samples, due to strong grain boundaries pinning. On the other hand, the high-temperature sintered samples have higher Jc at low fields compared to low-temperature sintered samples, mainly owing to their better crystallinity and grain connectivity. The highest Jc value (2.20 ×105 A cm-2 at 20 K, self-field) is obtained in the Mg11B2 sample sintered at 850 °C for 45 min.

  1. On the luminescence of Ti4+ In Mg5SnB2O10 and Mg3ZrB2O8

    NARCIS (Netherlands)

    Konijnendijk, W.L.; Blasse, G.

    1985-01-01

    The following new compounds are reported: Mg5TiB2O10 (ludwigite structure), Mg5SnB2O10 (orthopinakiolite structure) and Mg3ZrB2O8 (warwickite structure). The luminescences of the systems Mg5(Sn,Tl)B2O10 and Mg3(Zr,Ti)B2O8 were measured. The results are discussed in terms of delocalization in cluster

  2. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  3. D and DR Reactors

    Data.gov (United States)

    Federal Laboratory Consortium — The world's second full-scale nuclear reactor was the D Reactor at Hanford which was built in the early 1940's and went operational in December of 1944.D Reactor ran...

  4. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  5. Remaining Sites Verification Package for the 126-B-2, 183-B Clearwells, Waste Site Reclassification Form 2007-004

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-03-20

    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.

  6. High-resolution photoemission study of MgB2.

    Science.gov (United States)

    Takahashi, T; Sato, T; Souma, S; Muranaka, T; Akimitsu, J

    2001-05-21

    We have performed high-resolution photoemission spectroscopy on MgB2 and observed opening of a superconducting gap with a narrow coherent peak. We found that the superconducting gap is s like with the gap value ( Delta) of 4.5+/-0.3 meV at 15 K. The temperature dependence (15-40 K) of the gap value follows well the BCS form, suggesting that 2Delta/k(B)T(c) at T = 0 is about 3. No pseudogap behavior is observed in the normal state. The present results strongly suggest that MgB2 is categorized into a phonon-mediated BCS superconductor in the weak-coupling regime.

  7. Evidence for two superconducting gaps in MgB2.

    Science.gov (United States)

    Chen, X K; Konstantinovic, M J; Irwin, J C; Lawrie, D D; Franck, J P

    2001-10-01

    We have measured the Raman spectra of polycrystalline MgB2 from 25 to 1200 cm(-1). A superconductivity-induced redistribution in the electronic Raman continuum was observed. Two pair-breaking peaks appear in the spectra, suggesting the presence of two superconducting gaps. The measured spectra were analyzed using a quasi-two-dimensional model in which two s-wave superconducting gaps open on two sheets of Fermi surface. For the gap values we have obtained Delta(1) = 22 cm(-1) ( 2.7 meV) and Delta(2) = 50 cm(-1) ( 6.2 meV). Our results suggest that a conventional phonon-mediated pairing mechanism occurs in the planar boron sigma bands and is responsible for the superconductivity of MgB2.

  8. Attempts at doping indium in MgB2

    Science.gov (United States)

    Grivel, J.-C.

    2016-12-01

    Indium (In) doped MgB2 polycrystalline samples were prepared by solid-liquid phase reaction in Ar. After reaction at 800 °C, less than 1 at.% Mg was replaced by In in the MgB2 phase, without significant influence on its lattice parameters and only a slight decrease of its superconducting transition temperature. For all studied In concentrations in the nominal composition, the formation of InMg was evidenced by X-ray diffraction. The critical current density and accommodation field of the wires are decreased in the samples containing In. The flux pinning mechanism can be described by surface pinning in both the doped and undoped samples.

  9. Permanent magnet with MgB2 bulk superconductor

    Science.gov (United States)

    Yamamoto, Akiyasu; Ishihara, Atsushi; Tomita, Masaru; Kishio, Kohji

    2014-07-01

    Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB2) makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week with an extremely high stability (cryocoolers, making MgB2 bulks promising for the next generation of Tesla-class permanent-magnet applications.

  10. B2B Integration in Global Supply Chains

    DEFF Research Database (Denmark)

    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...... and is independent of specific implementation technologies. In the next stage of the research the emerging reference model will be extended to create an assessment model for analysing the maturity level of a given company in a specific supply chain....

  11. Structured Crowdsourcing: A B2B Innovation Roadmap

    DEFF Research Database (Denmark)

    Edgeman, Rick; Engell, Toke; Jensen, Nik Grewy

    Crowdsourcing is an increasingly popular source of both ideas and funding. Crowdsourcing in a B2B context is less well understood and, as such, much of our discussion will highlight business-to-business crowdsourcing. More generally discussion will address crowdsourcing relative to innovation...... from crowd-sourcing efforts. The roadmap emphasizes on early stages in the overall innovation management activity that is related to development and specification of the task to be crowdsourced, the identification of the crowd, the creation of the environment to connect the crowdsourcer, the task...... and the crowd, motivation of the crowd, and actual activities in reaching the crowd. Managing the input from the crowd is regarded as a later stage in the overall innovation management but also as a focal point in the arguments for improving B2B crowdsourcing. In crowd selection processes this paper aims...

  12. Heterostructures of Bi-4334 and MgB2 superconductors

    Science.gov (United States)

    Padmavathi, M.; Singh, R.

    2016-05-01

    We report the studies on hetero structures of Bi-4334 and MgB2 superconductors. The two superconductors were arranged in the form of bulk multilayers using hydraulic pressure system. X-ray diffraction pattern and dc magnetization studies confirm the presence of both superconducting phases in this try-layer hetero structured sample. The d.c magnetization shows the superconducting onset at 77K and 39K for Bi-4334 and MgB2 phases respectively. Critical current density (Jc) is calculated from hysteresis loop of the sample in both in-plane field and out of plane field configurations. Inverted anisotropy in Jc is observed due to enhancement of ab-plane properties because of multilayer growth process. Morphology of the samples at surface and interface of two superconducting layers is discussed in view of Field emission scanning electron microscopy.

  13. Superconductivity in MgB2 irradiated with energetic protons

    Science.gov (United States)

    Sandu, Viorel; Craciun, Liviu; Ionescu, Alina Marinela; Aldica, Gheorghe; Miu, Lucica; Kuncser, Andrei

    2016-09-01

    A series of MgB2 samples were irradiated with protons of 11.3 and 13.2 MeV. Magnetization data shows an insignificant reduction of the critical temperatures but a continuous decrease of the Meissner fraction with increasing fluence or energy. All samples show a consistent improvement of the critical current density compared to the virgin sample and an increase of the pinning energy at high fields as resulted from relaxation data.

  14. B2B Models for DoD Acquisition

    Science.gov (United States)

    2008-01-15

    business (B2B) e- commerce refers to transactions between businesses conducted electronically over the Internet, intranets, extranets, or private...types of electronic marketplace participation: 1) Sell-side, 2) Buy- side, 3) Exchanges, and 4) Collaborative commerce . In sell-side commerce , there...types are collectively referred to as company-centric electronic commerce , because they address a single company buying or selling needs. Exchanges

  15. Inbound-markkinoinnin opas pienille B2B-asiantuntijayrityksille

    OpenAIRE

    Halonen, Tuija

    2016-01-01

    Digitalisaatio on muuttanut asiakkaiden ostokäyttäytymistä, minkä vuoksi myös markkinoinnin on muututtava. Asiakaslähtöinen inbound-markkinointi on vetovoimainen vaihtoehto perinteiselle yksisuuntaiselle markkinoinnille, jonka teho on laskussa. Tämän toiminnallisen opinnäytetyön tarkoituksena oli rakentaa opas, joka auttaa pieniä suomalaisia B2B-asiantuntijayrityksiä suunnittelemaan ja toteuttamaan toimivaa ja kustannustehokasta inbound-markkinointia. Teoreettisen viitekehyksen pohjal...

  16. Performance and Applications of L1B2 Ultrasonic Motors

    OpenAIRE

    Gal Peled; Roman Yasinov; Nir Karasikov

    2016-01-01

    Piezoelectric ultrasonic motors offer important advantages for motion applications where high speed is coupled with high precision. The advances made in the recent decades in the field of ultrasonic motor based motion solutions allow the construction of complete motion platforms in the fields of semiconductors, aerospace and electro-optics. Among the various motor designs, the L1B2 motor type has been successful in industrial applications, offering high precision, effective control and operat...

  17. Itinerant magnetism in CeRh3B2

    OpenAIRE

    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 this a qualitative explanation for the anomalously high Curie temperature of the compound is proposed. Furthermore, the spin density is found to be highly nonspherical.

  18. Itinerant magnetism in CeRh3B2

    Science.gov (United States)

    Eriksson, Olle; Johansson, Börje; Brooks, M. S. S.; Skriver, H. L.; Sjöström, Jörgen

    1989-09-01

    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 this a qualitative explanation for the anomalously high Curie temperature of the compound is proposed. Furthermore, the spin density is found to be highly nonspherical.

  19. CO and its Isotopomers Observation towards Sgr B2

    Indian Academy of Sciences (India)

    L. L. Sun; J. S. Zhang; D. R. Lu; J. J. Qiu

    2014-09-01

    We present our observations toward Sgr B2 region in = 1−0 lines of 12CO, 13CO, C18O and C17O using 13.7-m Delingha millimeter telescope with newly installed 9-beam SIS superconducting receiver. From the integrated line intensity, we derive the abundance ratio of C18O/C17O with a mean value of 3.11 ± 0.10, which is consistent with the previous results.

  20. Biotechnological production of vitamin B2-enriched bread and pasta.

    Science.gov (United States)

    Capozzi, Vittorio; Menga, Valeria; Digesu, Anna Maria; De Vita, Pasquale; van Sinderen, Douwe; Cattivelli, Luigi; Fares, Clara; Spano, Giuseppe

    2011-07-27

    Lactic acid bacteria (LAB) were obtained from durum wheat flour samples and screened for roseoflavin-resistant variants to isolate natural riboflavin-overproducing strains. Two riboflavin-overproducing strains of Lactobacillus plantarum isolated as described above were used for the preparation of bread (by means of sourdough fermentation) and pasta (using a prefermentation step) to enhance their vitamin B2 content. Pasta was produced from a monovarietal semolina obtained from the durum wheat cultivar PR22D89 and, for experimental purposes, from a commercial remilled semolina. Several samples were collected during the pasta-making process (dough, extruded, dried, and cooked pasta) and tested for their riboflavin content by a high-performance liquid chromatography method. The applied approaches resulted in a considerable increase of vitamin B2 content (about 2- and 3-fold increases in pasta and bread, respectively), thus representing a convenient and efficient food-grade biotechnological application for the production of vitamin B2-enriched bread and pasta. This methodology may be extended to a wide range of cereal-based foods, feed, and beverages. Additionally, this work exemplifies the production of a functional food by a novel biotechnological exploitation of LAB in pasta-making.

  1. Modernization of B-2 Data, Video, and Control Systems Infrastructure

    Science.gov (United States)

    Cmar, Mark D.; Maloney, Christian T.; Butala, Vishal D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Spacecraft Propulsion Research Facility, commonly referred to as B-2, is NASA s third largest thermal-vacuum facility with propellant systems capability. B-2 has completed a modernization effort of its facility legacy data, video and control systems infrastructure to accommodate modern integrated testing and Information Technology (IT) Security requirements. Integrated systems tests have been conducted to demonstrate the new data, video and control systems functionality and capability. Discrete analog signal conditioners have been replaced by new programmable, signal processing hardware that is integrated with the data system. This integration supports automated calibration and verification of the analog subsystem. Modern measurement systems analysis (MSA) tools are being developed to help verify system health and measurement integrity. Legacy hard wired digital data systems have been replaced by distributed Fibre Channel (FC) network connected digitizers where high speed sampling rates have increased to 256,000 samples per second. Several analog video cameras have been replaced by digital image and storage systems. Hard-wired analog control systems have been replaced by Programmable Logic Controllers (PLC), fiber optic networks (FON) infrastructure and human machine interface (HMI) operator screens. New modern IT Security procedures and schemes have been employed to control data access and process control flows. Due to the nature of testing possible at B-2, flexibility and configurability of systems has been central to the architecture during modernization.

  2. Agent-based services for B2B electronic commerce

    Science.gov (United States)

    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.

  3. Reactor and method of operation

    Science.gov (United States)

    Wheeler, John A.

    1976-08-10

    A nuclear reactor having a flattened reactor activity curve across the reactor includes fuel extending over a lesser portion of the fuel channels in the central portion of the reactor than in the remainder of the reactor.

  4. Deposition of MgB2 Superconducting Thick Films in Sol-Gel Method%溶液法制备MgB2超导膜研究

    Institute of Scientific and Technical Information of China (English)

    郭峥山; 陈艺灵; 冯庆荣

    2012-01-01

    The superconducting MgB2 thick films were deposited in sol-gel method on SiC and Al2O3 substrates. The viscous precursor solution, Mg( BH4 )2· Et2O, of the MgB2, was first prepared via chemical route. Next, the precursor sol, painted on the substrates, was annealed at a high temperature. Repetition of the painting procedure increased the film thickness, from 200 nm to 1 μm. Finally, the MgB2 thick films were obtained by carefully annealing the precursor coatings in the reactor, filled with low pressure hydrogen, mixed with a small amount of Mg vapor generated by evaporation of Mg ingot. The impacts of the solution processing and annealing conditions on the microstructures and properties of the MgB2 thick films were evaluated. The MgB2 thick films were characterized with X-ray diffraction, and canning electron microscopy - The transition temperature of the 10 μm thick MgB2 coating was found to be 37 K. The possible means to reduce the surface pore and defect densities, and the feasibility of scaling up the MgB2 deposition in sol-get method were also tentatively discussed.%介绍了利用溶液法制备Mg(BH4)2前驱体,进而在衬底上涂抹粘稠的Mg(BH4)2乙醚溶胶(Mg(BH4)2·Et2O)制备MgB2厚膜的方法,也可称为溶胶凝胶法制备MgB2.运用此种方法制备出了10 μm级厚度、转变温度达到37 K的MgB2超导厚膜.这种方法设备简单、制膜所需温度低、原料便宜,并且无毒无污染.更为重要的是,这种方法克服了困扰工业上因为硼(B)在采购、运输和存储过程中易于氧化的缺点,可以通过将Mg(BH4)2·Et2O溶胶直接在衬底上均匀甩胶,进而大规模制备MgB2带材.可见溶液法制备MgB2是一种有着很大应用潜力的方法.

  5. B2幅面的数码印刷机市场%The B2 Digital Press Market

    Institute of Scientific and Technical Information of China (English)

    Andrew Tribute

    2010-01-01

    @@ B2幅面单张纸数码印刷机看起来可能是印刷机制造商的圣杯.在20世纪90年代,Indigo定期在各个印刷展览会上推出未来B2幅面印刷机的样机.问题是,Indigo(未并入惠普以前)始终没能为印刷机开发出一个成像引擎.这样的话,展出的只是问题而不是解决方案.大多数单张纸数码印刷机的最大成像宽度可以达到14英寸(约35cm).

  6. Superconductivity in MgB2: clean or dirty?

    Science.gov (United States)

    Mazin, I I; Andersen, O K; Jepsen, O; Dolgov, O V; Kortus, J; Golubov, A A; Kuz'menko, A B; Van Der Marel, D

    2002-09-01

    A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB2. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and, presumably, a strong correlation between the critical temperature and the residual resistivity. No such correlation has been observed. We argue that this fact can be understood if the band disparity of the electronic structure is taken into account, not only in the superconducting state, but also in normal transport.

  7. Phonon dispersion and lifetimes in MgB2.

    Science.gov (United States)

    Shukla, Abhay; Calandra, Matteo; D'Astuto, Matteo; Lazzeri, Michele; Mauri, Francesco; Bellin, Christophe; Krisch, Michael; Karpinski, J; Kazakov, S M; Jun, J; Daghero, D; Parlinski, K

    2003-03-01

    We measure phonon dispersion and linewidth in a single crystal of MgB2 along the Gamma-A, Gamma-M, and A-L directions using inelastic x-ray scattering. We use density functional theory to compute the effect of both electron-phonon coupling and anharmonicity on the linewidth, obtaining excellent agreement with experiment. Anomalous broadening of the E(2g) phonon mode is found all along Gamma-A. The dominant contribution to the linewidth is always the electron-phonon coupling.

  8. Two-band superconductivity in MgB2.

    Science.gov (United States)

    Iavarone, M; Karapetrov, G; Koshelev, A E; Kwok, W K; Crabtree, G W; Hinks, D G; Kang, W N; Choi, Eun-Mi; Kim, Hyun Jung; Kim, Hyeong-Jin; Lee, S I

    2002-10-28

    The study of the anisotropic superconductor MgB2 using a combination of scanning tunneling microscopy and spectroscopy reveals two distinct energy gaps at Delta(1)=2.3 meV and Delta(2)=7.1 meV at 4.2 K. Different spectral weights of the partial superconducting density of states are a reflection of different tunneling directions in this multiband system. Temperature evolution of the tunneling spectra follows the BCS scenario [Phys. Rev. Lett. 3, 552 (1959)

  9. Strategic Insights from Mystery Shopping in B2B Relationships

    DEFF Research Database (Denmark)

    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....

  10. Microwave absorption studies of MgB2 superconductor

    Indian Academy of Sciences (India)

    M K Bhide; R M Kadam; M D Sastry; Ajay Singh; Shashwati Sen; Manmeet Kaur; D K Aswal; S K Gupta; V C Sahni

    2002-05-01

    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 absorption has been found to obey a $\\sqrt{H}$ dependence with two different slopes, which indicated a transition from strongly pinned lattice to flux flow regime.

  11. Ephrin-B2 and EphB2 regulation of astrocyte-meningeal fibroblast interactions in response to spinal cord lesions in adult rats.

    Science.gov (United States)

    Bundesen, Liza Q; Scheel, Tracy Aber; Bregman, Barbara S; Kromer, Lawrence F

    2003-08-27

    The present study provides the first evidence that signaling occurs between B-ephrins and EphB receptors in the adult CNS in response to injury. Specifically, our combined histological and biochemical data indicate that two members of the B-class of ephrins and Eph receptors, ephrin-B2 and EphB2, are expressed by astrocytes and meningeal fibroblasts, respectively, in the adult spinal cord. In response to thoracic spinal cord transection lesions, ephrin-B2 and EphB2 protein levels exhibit an initial decrease (1 d after lesion), followed by a significant increase by day 14. Immunohistochemical data indicate that ephrin-B2 is expressed by reactive CNS astrocytes, and EphB2 is present on fibroblasts invading the lesion site from the adjacent meninges. During the first 3 d after injury, there is intermingling of ephrin-B2-expressing reactive astrocytes at the lesion surface with EphB2-containing fibroblasts that is concurrent with bidirectional activation (phosphorylation) of ephrin-B2 and EphB2. By 7 d, both cell types are establishing restricted cellular domains containing dense networks of cells and interweaving processes. This astroglial-meningeal fibroblast scar is fully developed by day 14 when there is strict segregation of ephrin-B2-expressing astrocytes from EphB2-positive meningeal fibroblasts. These morphological changes are concomitant with a simultaneous decrease in ephrin-B2 and EphB2 activation. These observations provide strong evidence that cell contact-mediated bidirectional signaling between ephrin-B2 on reactive astrocytes and EphB2 on meningeal fibroblasts is an early event in the cellular cascades that result in the development of the glial scar and the exclusion of meningeal fibroblasts from the injured spinal cord.

  12. Characterization of MgB2 Superconducting Hot Electron Bolometers

    Science.gov (United States)

    Cunnane, D.; Kawamura, J. H.; Wolak, M. A.; Acharya, N.; Tan, T.; Xi, X. X.; Karasik, B. S.

    2014-01-01

    Hot-Electron Bolometer (HEB) mixers have proven to be the best tool for high-resolution spectroscopy at the Terahertz frequencies. However, the current state of the art NbN mixers suffer from a small intermediate frequency (IF) bandwidth as well as a low operating temperature. MgB2 is a promising material for HEB mixer technology in view of its high critical temperature and fast thermal relaxation allowing for a large IF bandwidth. In this work, we have fabricated and characterized thin-film (approximately 15 nanometers) MgB2-based spiral antenna-coupled HEB mixers on SiC substrate. We achieved the IF bandwidth greater than 8 gigahertz at 25 degrees Kelvin and the device noise temperature less than 4000 degrees Kelvin at 9 degrees Kelvin using a 600 gigahertz source. Using temperature dependencies of the radiation power dissipated in the device we have identified the optical loss in the integrated microantenna responsible as a cause of the limited sensitivity of the current mixer devices. From the analysis of the current-voltage (IV) characteristics, we have derived the effective thermal conductance of the mixer device and estimated the required local oscillator power in an optimized device to be approximately 1 microwatts.

  13. Multilayer MgB2 superconducting quantum interference filter magnetometers

    Science.gov (United States)

    Galan, Elias; Melbourne, Thomas; Davidson, Bruce A.; Xi, X. X.; Chen, Ke

    2016-04-01

    We report two types of all-MgB2 superconductive quantum interference filter (SQIF) magnetometers that can measure absolute magnetic fields with high sensitivity. In one configuration, the SQIFs were made of 20 multilayer nonplanar all-MgB2 superconducting quantum interference devices (SQUIDs) connected in parallel with loop areas ranging in size from 0.4 to 3.6 μm2. These devices are sensitive to magnetic fields parallel to the substrate and show a single antipeak from 3 to 16 K with a maximum transfer function of ˜16 V/T at 3 K and a field noise of ˜110 pT/Hz1/2 above 100 Hz at 10 K. In a second configuration, the SQIFs were made with 16 planar SQUIDs connected in parallel with loop areas ranging in size from 4 μm2 to 25 μm2 and are sensitive to the magnetic fields perpendicular to the substrate. The planar SQIF shows a single antipeak from 10 to 22 K with a maximum transfer function of 7800 V/T at 10 K and a field noise of ˜70 pT/Hz1/2 above 100 Hz at 20 K.

  14. Low-noise THz MgB2 Josephson mixer

    Science.gov (United States)

    Cunnane, Daniel; Kawamura, Jonathan H.; Acharya, Narendra; Wolak, Matthäus A.; Xi, X. X.; Karasik, Boris S.

    2016-09-01

    The potential applications for high frequency operation of the Josephson effect in MgB2 include THz mixers, direct detectors, and digital circuits. Here we report on MgB2 weak links which exhibit the Josephson behavior up to almost 2 THz and using them for low-noise heterodyne detection of THz radiation. The devices are made from epitaxial film grown in the c-axis direction by the hybrid physical-chemical vapor deposition method. The current in the junctions travels parallel to the surface of the film, thus making possible a large contribution of the quasi-two-dimensional σ-gap in transport across the weak link. These devices are connected to a planar spiral antenna with a dielectric substrate lens to facilitate coupling to free-space radiation for use as a detector. The IcRn product of the junction is 5.25 mV, giving confirmation of a large gap parameter. The sensitivity of the mixer was measured from 0.6 THz to 1.9 THz. At a bath temperature of over 20 K, a mixer noise temperature less than 2000 K (DSB) was measured near 0.6 THz.

  15. Detection of amino acetonitrile in Sgr B2(N)

    CERN Document Server

    Belloche, A; Comito, C; Müller, H S P; Schilke, P; Ott, J; Thorwirth, S; Hieret, C

    2008-01-01

    Amino acids are building blocks of proteins and therefore key ingredients for the origin of life. The simplest amino acid, glycine, has long been searched for in the interstellar medium but has not been unambiguously detected so far. Since the search for glycine has turned out to be extremely difficult, we aimed at detecting a chemically related species (possibly a direct precursor), amino acetonitrile. With the IRAM 30m telescope we carried out a complete line survey of the hot core regions Sgr B2(N) and (M) in the 3 mm range, plus partial surveys at 2 and 1.3 mm. We analyzed our 30m line survey in the LTE approximation and modeled the emission of all known molecules simultaneously. We identified spectral features at the frequencies predicted for amino acetonitrile lines having intensities compatible with a unique rotation temperature. We also used the VLA to look for cold, extended emission from amino acetonitrile. We detected amino acetonitrile in Sgr B2(N) in our 30m telescope line survey and conducted co...

  16. Preparation of highly preferred orientation TiB2 coatings

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper focuses on the preparation of titanium diboride (TiB2) coatings on the graphite substrate by continuous current plating (CCP) and pulse current plating (PIC) electrochemical techniques in fluoride electrolytes (LiF-NaF-KF)containing K2TiF6 and KBF4 as the electrochemically-active components at 700℃. Thick leveled and uniform coatings were obtained and were composed of relatively pure TiB2. The effect of the experimental parameters on the microstructure of the coatings was studied. The results showed the electrodeposition with PIC produced coatings with better quality, when compared with those obtained by CCP, under the conditions of the current density i = 0.6 A/cm2, frequency = 100 Hz, and ton/toff = 4/1. XRD analysis indicated that the preferred orientation of coatings is (110) plane, which is in accordance with the prediction of the two-dimensional crystal nuclei theory. The effect of a ratio of ton/toff and frequency on the crystal size, texture coefficient and microstress was also investigated.

  17. Vortex Lattice Transition Dynamics in MgB2

    Science.gov (United States)

    Rastovski, C.; Das, P.; Schlesinger, K.; Eskildsen, M. R.; Gannon, W. J.; Dewhurst, C. D.; Zhigadlo, N. D.; Karpinski, J.

    2012-02-01

    We present small-angle neutron scattering (SANS) studies of the vortex lattice (VL) in MgB2 with H c. This material has three different VL phases, all with triangular symmetry but oriented differently with respect to the crystalline axes. Furthermore, a high degree of metastability between the VL phases of MgB2 has been observed as the sample is cooled or heated across the equilibrium phase transitions. Here we present detailed studies of how the metastable (MS) VL phases transition to the ground state (GS), either driven by small changes of the DC magnetic field or by a transverse AC field. Our results show that the MS VL is not due to vortex pinning, and results are inconsistent with predictions based on the Bean model. Instead, we speculate that a ``jamming'' of counter rotated VL domains is responsible for the VL metastability. This is further supported by a power law dependence of the GS VL domain population upon the number of applied AC cycles. This work was supported by the Department of Energy, Basic Energy Sciences under Award No. DE-FG02-10ER46783.

  18. The rat ErbB2 tyrosine kinase receptor produced in plants is immunogenic in mice and confers protective immunity against ErbB2(+) mammary cancer.

    Science.gov (United States)

    Matić, Slavica; Quaglino, Elena; Arata, Lucia; Riccardo, Federica; Pegoraro, Mattia; Vallino, Marta; Cavallo, Federica; Noris, Emanuela

    2016-01-01

    The rat ErbB2 (rErbB2) protein is a 185-kDa glycoprotein belonging to the epidermal growth factor-related proteins (ErbB) of receptor tyrosine kinases. Overexpression and mutations of ErbB proteins lead to several malignancies including breast, lung, pancreatic, bladder and ovary carcinomas. ErbB2 is immunogenic and is an ideal candidate for cancer immunotherapy. We investigated the possibility of expressing the extracellular (EC) domain of rErbB2 (653 amino acids, aa) in Nicotiana benthamiana plants, testing the influence of the 23 aa transmembrane (TM) sequence on protein accumulation. Synthetic variants of the rErbB2 gene portion encoding the EC domain, optimized with a human codon usage and either linked to the full TM domain (rErbB2_TM, 676 aa), to a portion of it (rErbB2-pTM, 662 aa), or deprived of it (rErbB2_noTM, 653 aa) were cloned in the pEAQ-HT expression vector as 6X His tag fusions. All rErbB2 variants (72-74.5 kDa) were transiently expressed, but the TM was detrimental for rErbB2 EC accumulation. rERbB2_noTM was the most expressed protein; it was solubilized and purified with Nickel affinity resin. When crude soluble extracts expressing rErbB2_noTM were administered to BALB/c mice, specific rErbB2 immune responses were triggered. A potent antitumour activity was induced when vaccinated mice were challenged with syngeneic transplantable ErbB2(+) mammary carcinoma cells. To our knowledge, this is the first report of expression of rErbB2 in plants and of its efficacy in inducing a protective antitumour immune response, opening interesting perspectives for further immunological testing.

  19. Interação entre Hb B2 e Hb S Interaction between Hb B2 and Hb S

    Directory of Open Access Journals (Sweden)

    Natália Ferreira

    2010-02-01

    Full Text Available As hemoglobinopatias e talassemias constituem as afecções genéticas mais comuns, apresentando-se, na maioria dos casos, em heterozigose. Diante da diversidade de hemoglobinas variantes encontrada na população brasileira, metodologias específicas e complementares para um diagnóstico laboratorial preciso, capaz de elucidar possíveis interações entre estas variantes genéticas, são necessárias. Este relato de caso descreve a interação entre hemoglobina B2 e a hemoglobina S em um indivíduo do sexo feminino, caucasoide, proveniente da região Sudeste do Brasil, identificada por meio de técnicas eletroforéticas em diferentes pH, cromatografia líquida de alta performance e PCR- RFLP. Visto que a hemoglobina B2 coelui com a hemoglobina S na análise cromatográfica e dificilmente é visualizada em eletroforese pH alcalino, devido à sua baixa concentração, justifica-se a necessidade da associação de testes laboratoriais, inclusive moleculares, na rotina do diagnóstico de hemoglobinas para a correta identificação do perfil de hemoglobinas do indivíduo e real frequência na população brasileira. Rev. Bras. Hematol. Hemoter.Hemoglobinopathies and thalassemias are the most common genetic diseases, and in most cases, present as heterozygous. Due to the diversity of hemoglobin variants, specific and complementary methodologies are necessary for a precise laboratorial diagnosis, able to elucidate possible interactions between genetic polymorphisms. This case report describes an interaction between hemoglobin B2 and hemoglobin S in a Caucasian woman from the southeastern region of Brazil. This interaction was identified by electrophoresis in different pHs, high performance liquid chromatography and PCR-RFLP. As hemoglobin B2 is eluted in the same window as hemoglobin S in automatic HPLC systems and is hardly seen in alkaline electrophoresis due to its low concentration, the association must be confirmed using additional laboratorial

  20. The Microwave Sintering Technology and Its Application in the Synthesis of ZrB2

    Institute of Scientific and Technical Information of China (English)

    HE Zhiyong; LI Lin; PENG Xiaoyan

    2005-01-01

    The principles and features of microwave sintering, the application in refractories and synthesis methods of ZrB2 are reviewed. The synthesis results of ZrB2 by thermit deoxidate method show that production price of ZrB2 can be effectively lowered through microwave synthesis. It will expand the application of ZrB2 in refractories.

  1. The bradykinin B2 receptor in the early immune response against Listeria infection

    NARCIS (Netherlands)

    Kaman, W.E.; Wolterink, A.F.W.M.; Bader, M.; Boele, L.C.L.; Kleij, D. van der

    2009-01-01

    The endogenous danger signal bradykinin was recently found implicated in the development of immunity against parasites via dendritic cells. We here report an essential role of the B2 (B2R) bradykinin receptor in the early immune response against Listeria infection. Mice deficient in B2R (B2R-/- mice

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

    CERN Document Server

    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.

  3. Combustion Synthesis of TiB2 Ceramics Powder from B2O3-TiO2-Mg System in Air Atmosphere

    Institute of Scientific and Technical Information of China (English)

    HE Jinyun; WANG Weimin; FU Zhengyi; SUN Hui

    2005-01-01

    TiB2 ceramics powder was synthesized from B2O3-TiO2-Mg system. The effects of TiB2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experiments show that the increase of TiB2 content ranging from 0 to 20wt% can reduce the adiabatic temperature Tad from 3100 K to 2896 K and combustion temperature Tc from 2139 K to 1621 K respectively. The particle size and half width of the particle distribution are also increased with the addition of TiB2 increasing from 0 to 20wt%. The combustion product is a mixture of TiB2, MgO, and other intermediate phases. The leached product contains mainly TiB2, TiO2 and TiN, and its oxygen content is 7.77wt%.

  4. Sulla razionalità delle 3-varietà di Fano con B_2 almeno 2

    Directory of Open Access Journals (Sweden)

    Alberto Alzati

    1992-05-01

    Full Text Available Complex, smooth, projective Fano varieties were classified by Iskovskih when B2 =1 (B2 is the second Betti number and by Mori and Mukai when B2  is at least 2. When B2 =1 it is known if such varieties are rational (unirational or not; in this paper we solve this problem when B2  greater or equal 2.

  5. Structural and thermodynamic properties of AlB2 compound

    Institute of Scientific and Technical Information of China (English)

    Zhou Xiao-Lin; Liu Ke; Chen Xiang-Rong; Zhu Jun

    2006-01-01

    We employ a first-principles plane wave method with the relativistic analytic pseudopotential of Hartwigsen,Goedecker and Hutter (HGH) scheme in the frame of DFT to calculate the equilibrium lattice parameters and the thermodynamic properties of AlB2 compound with hcp structure. The obtained lattice parameters are in good agreement with the available experimental data and those calculated by others. Through the quasi-harmonic Dcbye model, obtained successfully are the dependences of the normalized lattice parameters a/a0 and c/c0 on pressure P, the normalized primitive cell volume V/Vo on pressure P, the variation of the thermal expansion α with pressure P and temperature T, as well as the Debye temperature θD and the heat capacity CV on pressure P and temperature T.

  6. Scanning tunneling spectroscopy in MgB2.

    Science.gov (United States)

    Karapetrov, G; Iavarone, M; Kwok, W K; Crabtree, G W; Hinks, D G

    2001-05-01

    We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39 K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a smearing parameter gamma. The value of the superconducting gap is 5 meV at 4.2 K, with no experimentally significant variation across the surface of the sample. The temperature dependence of the gap follows the BCS form, fully consistent with phonon-mediated superconductivity in this novel superconductor. The application of a magnetic field induces strong pair breaking as seen in the conductance spectra in fields up to 6 T.

  7. Relationship Quality as Predictor of B2B Customer Loyalty

    Directory of Open Access Journals (Sweden)

    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.

  8. Enhanced MgB2 Superconductivity Under High Pressure

    Institute of Scientific and Technical Information of China (English)

    刘振兴; 靳常青; 游江洋; 李绍春; 朱嘉林; 禹日成; 李风英; 苏少奎

    2002-01-01

    We report on in situ high-pressure studies up to 1.0 GPa on the MgB2 superconductor which was high-pressure synthesized. The as-prepared sample is of high quality in terms of sharp superconducting transition (Tc) at 39K from the magnetic measurements. The in situ high-pressure measurements were carried out using a Be-Cu piston-cylinder-type instrument with mixed oil as the pressure transmitting medium which warrants a quasihydrostatic pressure environment at low temperature. The superconducting transitions were measured using the electrical conductance method. It is found that Tc increases by more than 1 K with pressure in the low-pressure range, before the Tc value decreases with the further increase of the pressure.

  9. Vortex lattice transitions in YNi2B2C

    Indian Academy of Sciences (India)

    S J Levett; C D Dewhurst; D McK Paul

    2002-05-01

    We have performed extensive small-angle neutron scattering (SANS) diffraction studies of the vortex lattice in single crystal YNi2B2C for $B||c$. High-resolution SANS, combined with a field-oscillation vortex lattice preparation technique, allows us to separate Bragg scattered intensities from two orthogonal domains and accurately determine the unit cell angle, . The data suggest that upon increasing field there is a finite transition width where both low- and high-field distorted hexagonal vortex lattice phases, mutually rotated by 45°, coexist. The smooth variation of diffracted intensity from each phase through the transition corresponds to a redistribution of populations between the two types of domains.

  10. Semantic ETL into i2b2 with Eureka!

    Science.gov (United States)

    Post, Andrew R; Krc, Tahsin; Rathod, Himanshu; Agravat, Sanjay; Mansour, Michel; Torian, William; Saltz, Joel H

    2013-01-01

    Clinical phenotyping is an emerging research information systems capability. Research uses of electronic health record (EHR) data may require the ability to identify clinical co-morbidities and complications. Such phenotypes may not be represented directly as discrete data elements, but rather as frequency, sequential and temporal patterns in billing and clinical data. These patterns' complexity suggests the need for a robust yet flexible extract, transform and load (ETL) process that can compute them. This capability should be accessible to investigators with limited ability to engage an IT department in data management. We have developed such a system, Eureka! Clinical Analytics. It extracts data from an Excel spreadsheet, computes a broad set of phenotypes of common interest, and loads both raw and computed data into an i2b2 project. A web-based user interface allows executing and monitoring ETL processes. Eureka! is deployed at our institution and is available for deployment in the cloud.

  11. Performance and Applications of L1B2 Ultrasonic Motors

    Directory of Open Access Journals (Sweden)

    Gal Peled

    2016-06-01

    Full Text Available Piezoelectric ultrasonic motors offer important advantages for motion applications where high speed is coupled with high precision. The advances made in the recent decades in the field of ultrasonic motor based motion solutions allow the construction of complete motion platforms in the fields of semiconductors, aerospace and electro-optics. Among the various motor designs, the L1B2 motor type has been successful in industrial applications, offering high precision, effective control and operational robustness. This paper reviews the design of high precision motion solutions based on L1B2 ultrasonic motors—from the basic motor structure to the complete motion solution architecture, including motor drive and control, material considerations and performance envelope. The performance is demonstrated, via constructed motion stages, to exhibit fast move and settle, a repeatability window of tens of nanometers, lifetime into the tens of millions of operational cycles, and compatibility with clean room and aerospace environments. Example stages and modules for semiconductor, aerospace, electro-optical and biomedical applications are presented. The described semiconductor and aerospace solutions are powered by Nanomotion HR type motors, driven by a sine wave up to 80 V/mm rms, having a driving frequency of 39.6 kHz, providing a maximum force up to 4 N per driving element (at 5 W power consumption per element and a maximum linear velocity above 300 mm/s. The described electro-optical modules are powered by small Nanomotion Edge motors driven by voltages up to 11 V AC, providing stall forces up to 0.35 N (power consumption up to 0.75 W and maximum linear velocity above 200 mm/s.

  12. Reactor Physics Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Raedt, C

    2000-07-01

    The Reactor Physics and 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 on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research 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. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies.

  13. Effect of TiB2 content on resistance to sodium penetration of TiB2/C cathode composites for aluminium electrolysis

    Institute of Scientific and Technical Information of China (English)

    李劼; 方静; 李庆余; 赖延清

    2004-01-01

    TiB2/C cathode composites with various contents of TiB2 were prepared and their characterizations were observed and compared. The expansion of samples due to sodium and bath penetration was tested with a modified laboratory Rapoport apparatus and the appearances of the cut sections of specimens after electrolysis were studied.The results show that the mass of TiB2/C cathode composites with mass fraction of TiB2 less than 70 % appreciably increases, but that of the composites with mass fraction of TiB2 more than 70% decreases slightly after being baked.The resistance to sodium and bath penetration of TiB2/C cathode composites increases with the increase of TiB2 content, especially in the composites with high TiB2 content. TiB2/C cathode composites have high resistance to the penetration of sodium and bath as well as good wettability by molten aluminum, and keep integrality and have little change of appearance after electrolysis, which indicates that TiB2/C cathode composites can be used as inert wettable cathode for aluminum electrolysis.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. Inhibition of ErbB-2 Mitogenic and Transforming Activity by RALT, a Mitogen-Induced Signal Transducer Which Binds to the ErbB-2 Kinase Domain†

    Science.gov (United States)

    Fiorentino, Loredana; Pertica, Chiara; Fiorini, Monia; Talora, Claudio; Crescenzi, Marco; Castellani, Loriana; Alemà, Stefano; Benedetti, Piero; Segatto, Oreste

    2000-01-01

    The product of rat gene 33 was identified as an ErbB-2-interacting protein in a two-hybrid screen employing the ErbB-2 juxtamembrane and kinase domains as bait. This interaction was reproduced in vitro with a glutathione S-transferase fusion protein spanning positions 282 to 395 of the 459-residue gene 33 protein. Activation of ErbB-2 catalytic function was required for ErbB-2–gene 33 physical interaction in living cells, whereas ErbB-2 autophosphorylation was dispensable. Expression of gene 33 protein was absent in growth-arrested NIH 3T3 fibroblasts but was induced within 60 to 90 min of serum stimulation or activation of the ErbB-2 kinase and decreased sharply upon entry into S phase. New differentiation factor stimulation of mitogen-deprived mammary epithelial cells also caused accumulation of gene 33 protein, which could be found in a complex with ErbB-2. Overexpression of gene 33 protein in mouse fibroblasts inhibited (i) cell proliferation driven by ErbB-2 but not by serum, (ii) cell transformation induced by ErbB-2 but not by Ras or Src, and (iii) sustained activation of ERK 1 and 2 by ErbB-2 but not by serum. The gene 33 protein may convey inhibitory signals downstream to ErbB-2 by virtue of its association with SH3-containing proteins, including GRB-2, which was found to associate with gene 33 protein in living cells. These data indicate that the gene 33 protein is a feedback inhibitor of ErbB-2 mitogenic function and a suppressor of ErbB-2 oncogenic activity. We propose that the gene 33 protein be renamed with the acronym RALT (receptor-associated late transducer). PMID:11003669

  17. Inhibition of ErbB-2 mitogenic and transforming activity by RALT, a mitogen-induced signal transducer which binds to the ErbB-2 kinase domain.

    Science.gov (United States)

    Fiorentino, L; Pertica, C; Fiorini, M; Talora, C; Crescenzi, M; Castellani, L; Alemà, S; Benedetti, P; Segatto, O

    2000-10-01

    The product of rat gene 33 was identified as an ErbB-2-interacting protein in a two-hybrid screen employing the ErbB-2 juxtamembrane and kinase domains as bait. This interaction was reproduced in vitro with a glutathione S-transferase fusion protein spanning positions 282 to 395 of the 459-residue gene 33 protein. Activation of ErbB-2 catalytic function was required for ErbB-2-gene 33 physical interaction in living cells, whereas ErbB-2 autophosphorylation was dispensable. Expression of gene 33 protein was absent in growth-arrested NIH 3T3 fibroblasts but was induced within 60 to 90 min of serum stimulation or activation of the ErbB-2 kinase and decreased sharply upon entry into S phase. New differentiation factor stimulation of mitogen-deprived mammary epithelial cells also caused accumulation of gene 33 protein, which could be found in a complex with ErbB-2. Overexpression of gene 33 protein in mouse fibroblasts inhibited (i) cell proliferation driven by ErbB-2 but not by serum, (ii) cell transformation induced by ErbB-2 but not by Ras or Src, and (iii) sustained activation of ERK 1 and 2 by ErbB-2 but not by serum. The gene 33 protein may convey inhibitory signals downstream to ErbB-2 by virtue of its association with SH3-containing proteins, including GRB-2, which was found to associate with gene 33 protein in living cells. These data indicate that the gene 33 protein is a feedback inhibitor of ErbB-2 mitogenic function and a suppressor of ErbB-2 oncogenic activity. We propose that the gene 33 protein be renamed with the acronym RALT (receptor-associated late transducer).

  18. Photo-activated psoralen binds the ErbB2 catalytic kinase domain, blocking ErbB2 signaling and triggering tumor cell apoptosis.

    Directory of Open Access Journals (Sweden)

    Wenle Xia

    Full Text Available Photo-activation of psoralen with UVA irradiation, referred to as PUVA, is used in the treatment of proliferative skin disorders. The anti-proliferative effects of PUVA have been largely attributed to psoralen intercalation of DNA, which upon UV treatment, triggers the formation of interstrand DNA crosslinks (ICL that inhibit transcription and DNA replication. Here, we show that PUVA exerts antitumor effects in models of human breast cancer that overexpress the ErbB2 receptor tyrosine kinase oncogene, through a new mechanism. Independent of ICL formation, the antitumor effects of PUVA in ErbB2+ breast cancer models can instead be mediated through inhibition of ErbB2 activation and signaling. Using a mass spectroscopy-based approach, we show for the first time that photo-activated 8MOP (8-methoxypsoralen interacts with the ErbB2 catalytic autokinase domain. Furthermore, PUVA can reverse therapeutic resistance to lapatinib and other ErbB2 targeted therapies, including resistance mediated via expression of a phosphorylated, truncated form of ErbB2 (p85(ErbB2 that is preferentially expressed in tumor cell nuclei. Current ErbB2 targeted therapies, small molecule kinase inhibitors or antibodies, do not block the phosphorylated, activated state of p85(ErbB2. Here we show that PUVA reduced p85(ErbB2 phosphorylation leading to tumor cell apoptosis. Thus, in addition to its effects on DNA and the formation of ICL, PUVA represents a novel ErbB2 targeted therapy for the treatment of ErbB2+ breast cancers, including those that have developed resistance to other ErbB2 targeted therapies.

  19. High-temperature vaporization of B2O3(l) under reducing conditions.

    Science.gov (United States)

    Jacobson, Nathan S; Myers, Dwight L

    2011-11-17

    The vaporization of B(2)O(3) in a reducing environment leads to the formation of both B(2)O(3)(g) and B(2)O(2)(g). Whereas the formation of B(2)O(3)(g) is well understood, many questions about the formation of B(2)O(2)(g) remain. Previous studies using B(s) + B(2)O(3)(l) have led to inconsistent thermodynamic data. In this study, it was found that, after heating, B(s) and B(2)O(3)(l) appeared to separate and variations in contact area likely led to the inconsistent vapor pressures of B(2)O(2)(g). To circumvent this problem, the activity of boron was fixed with a two-phase mixture of FeB and Fe(2)B. Both second- and third-law enthalpies of formation were measured for B(2)O(2)(g) and B(2)O(3)(g). From these values, the enthalpies of formation at 298.15 K were calculated to be -479.9 ± 25.7 kJ/mol for B(2)O(2)(g) and -833.4 ± 13.1 kJ/mol for B(2)O(3)(g). Ab initio calculations to determine the enthalpies of formation of B(2)O(2)(g) and B(2)O(3)(g) were conducted using the W1BD composite method and showed good agreement with the experimental values.

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

    Science.gov (United States)

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

    2011-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 are candidate materials for applications in extreme environments because of their high melting point, good mechanical properties and reasonable oxidation resistance. Unlike many ceramics, these materials have high thermal conductivity which can be advantageous, for example, to reduce thermal shock. Recently, we developed Tersoff style interatomic 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. Results at room temperature and at elevated temperatures will be reported.

  1. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hiroto

    1995-02-07

    A reactor container of the present invention has a structure that the reactor container is entirely at the same temperature as that at the inlet of the reactor and, a hot pool is incorporated therein, and the reactor container has is entirely at the same temperature and has substantially uniform temperature follow-up property transiently. Namely, if the temperature at the inlet of the reactor core changes, the temperature of the entire reactor container changes following this change, but no great temperature gradient is caused in the axial direction and no great heat stresses due to axial temperature distribution is caused. Occurrence of thermal stresses caused by the axial temperature distribution can be suppressed to improve the reliability of the reactor container. In addition, since the laying of the reactor inlet pipelines over the inside of the reactor is eliminated, the reactor container is made compact and the heat shielding structures above the reactor and a protection structure of container walls are simplified. Further, secondary coolants are filled to the outside of the reactor container to simplify the shieldings. The combined effects described above can improve economical property and reliability. (N.H.).

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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…

  4. Lightweight MgB2 superconducting 10 MW wind generator

    Science.gov (United States)

    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.

  5. Herschel observations of deuterated water towards Sgr B2(M)

    CERN Document Server

    Comito, Claudia; Rolffs, Rainer; Lis, D C; Belloche, A; Bergin, E A; Phillips, T G; Bell, T A; Crockett, N R; Wang, S; Blake, G A; Caux, E; Ceccarelli, C; Cernicharo, J; Daniel, F; Dubernet, M -L; Emprechtinger, M; Encrenaz, P; Gerin, M; Giesen, T F; Goicoechea, J R; Goldsmith, P F; Gupta, H; Herbst, E; Joblin, C; Johnstone, D; Langer, W D; Latter, W D; Lord, S D; Maret, S; Martin, P G; Melnick, G J; Menten, K M; Morris, P; Mueller, H S P; Murphy, J A; Neufeld, D A; Ossenkopf, V; Pearson, J C; Perault, M; Plume, R; Qin, S -L; Schlemmer, S; Stutzki, J; Trappe, N; van der Tak, F F S; Vastel, C; Yorke, H W; Yu, S; Olberg, M; Szczerba, R; Larsson, B; Liseau, R; Lin, R H; Samoska, L A; Schlecht, E

    2010-01-01

    Observations of HDO are an important complement for studies of water, because they give strong constraints on the formation processes -- grain surfaces versus energetic process in the gas phase, e.g. in shocks. The HIFI observations of multiple transitions of HDO in Sgr~B2(M) presented here allow the determination of the HDO abundance throughout the envelope, which has not been possible before with ground-based observations only. The abundance structure has been modeled with the spherical Monte Carlo radiative transfer code RATRAN, which also takes radiative pumping by continuum emission from dust into account. The modeling reveals that the abundance of HDO rises steeply with temperature from a low abundance ($2.5\\times 10^{-11}$) in the outer envelope at temperatures below 100~K through a medium abundance ($1.5\\times 10^{-9}$) in the inner envelope/outer core, at temperatures between 100 and 200~K, and finally a high abundance ($3.5\\times 10^{-9}$) at temperatures above 200~K in the hot core.

  6. Advanced Modelling and Functional Characterization of B2 Bradykinin Receptor

    Directory of Open Access Journals (Sweden)

    Muhammad Saad Khan

    2015-06-01

    Full Text Available Hereditary angioedema (giant hives is an autosomal dominant malady characterized by repetitive episodes of probably life-threatening angioedema due to a partial deficiency of C1 inhibitor. B2 Bradykinin Receptor's (BKRB2 amino acid sequence is deposited within UniProt under accession number P30411. The Physicochemical properties of BKRB2 sequence are determined by using ProtParam. BKRB2's secondary structure was predicted through PROTEUS. Pfam domain was used for functional characterization of BKRB2. PSI-BLAST was used to find homologs of known structure. Modelling by satisfaction of spatial restraints, either uses distance geometry or optimization techniques to satisfy spatial restraints performed by MODELLER. The quality of the generated model was evaluated with PROCHECK by Ramachandran plot analysis. Validation of the generated models was further performed by WHAT IF. ProSA was used for the analysis of Z-scores and energy plots. The 3D structures of the modeled proteins were analyzed using UCSF Chimera. Clustal Omega is used for multiple sequence alignment that uses seeded guide trees and HMM profile-profile techniques to generate alignments.

  7. Phonon linewidths in YNi2B2C

    Indian Academy of Sciences (India)

    L Pintschovius; F Weber; W Reichardt; A Kreyssig; R Heid; D Reznik; O Stockert; K Hradil

    2008-10-01

    Phonons in a metal interact with conduction electrons which give rise to a finite linewidth. In the normal state, this leads to a Lorentzian shape of the phonon line. Density functional theory is able to predict the phonon linewidths as a function of wave vector for each branch of the phonon dispersion. An experimental verification of such predictions is feasible only for compounds with very strong electron–phonon coupling. YN2B2C was chosen as a test example because it is a conventional superconductor with a fairly high c (15.2 K). Inelastic neutron scattering experiments did largely confirm the theoretical predictions. Moreover, they revealed a strong temperature dependence of the linewidths of some phonons with particularly strong electron–phonon coupling which can as yet only qualitatively be accounted for by theory. For such phonons, marked changes of the phonon frequencies and linewidths were observed from room temperature down to 15 K. Further changes were observed on entering into the superconducting state. These changes can, however, not be described simply by a change of the phonon linewidth.

  8. Electronic structure and superconductivity of MgB2

    Indian Academy of Sciences (India)

    D M Gaitonde; P Modak; R S Rao; B K Godwal

    2003-01-01

    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 experiment. We obtain the mass enhancement parameter by using our calculated, $D(E_F)$ and the experimental specific heat data. The $T_c$ is found to be 37 K. We use a parametrized description of the calculated band structure to obtain the = 0 K values of the London penetration depth and the superconducting coherence length. The penetration depth calculated by us is too small and the coherence length too large as compared to the experimentally determined values of these quantities. This indicates the limitations of a theory that relies only on electronic structure calculations in describing the superconducting state in this material and implies that impurity effects as well as mass renormalization effects need to be included.

  9. Thermodynamic and transport properties of superconducting Mg10B2.

    Science.gov (United States)

    Finnemore, D K; Ostenson, J E; Bud'ko, S L; Lapertot, G; Canfield, P C

    2001-03-12

    Transport and thermodynamic properties of a sintered pellet of the newly discovered MgB2 superconductor have been measured to determine the characteristic critical magnetic fields and critical current densities. Both resistive transition and magnetization data give similar values of the upper critical field, Hc2, with magnetization data giving dHc2/dT = 0.44 T/K at the transition temperature of Tc = 40.2 K. Close to the transition temperature, magnetization curves are thermodynamically reversible, but at low temperatures the trapped flux can be on the order of 1 T. The value of dHc/dT at Tc is estimated to be about 12 mT/K, a value similar to classical superconductors like Sn. Hence, the Ginzburg-Landau parameter kappa approximately 26. Estimates of the critical supercurrent density, Jc, using hysteresis loops and the Bean model, give critical current densities on the order of 10(5) A/cm2. Hence the supercurrent coupling through the grain boundaries is comparable to intermetallics like Nb3Sn.

  10. Scheme to prepare the MgB2 superconducting multilayer films%MgB2超导多层膜的制备方案

    Institute of Scientific and Technical Information of China (English)

    罗子江; 杨健; 王继红

    2007-01-01

    简要叙述了MgB2的发展和制备历史,通过对不同衬底材料上MgB2的反应情况的总结概括以及对不同衬底材料和MgB2的晶体结构和晶格常量的比较,提出一种MgB2超导多层膜的制备方案.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  12. Customer Behavior Analysis under B2C Environment%B2C环境下的客户行为分析

    Institute of Scientific and Technical Information of China (English)

    牛文博

    2012-01-01

    Taking the background of B2C e-commerce transactions, this paper starts from the objective of customer behavior analysis, proposes the process of customer behavior analysis based on B2C e-commerce environment, analyzes the customer's consumer psychology and behavior under B2C environment, and points out the customer retention strategy. This paper has a reference to B2C website.%本文以B2C电子商务交易过程为背景,从客户行为分析的目标出发,提出了基于B2C电子商务环境下的客户行为分析过程,并对B2C环境下的客户消费心理和行为进行了分析,提出了B2C环境下的客户保留策略,这对B2C网站具有借鉴意义.

  13. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate

  14. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M

    2010-01-01

    Nuclear reactor physics is the core discipline of nuclear engineering. Nuclear reactors now account for a significant portion of the electrical power generated worldwide, and new power reactors with improved fuel cycles are being developed. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. The second edition of this successful comprehensive textbook and reference on basic and advanced nuclear reactor physics has been completely updated, revised and enlarged to include the latest developme

  15. Spinning fluids reactor

    Science.gov (United States)

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  16. Thermal Vacuum Integrated System Test at B-2

    Science.gov (United States)

    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.

  17. Thermal vacuum integrated system test at B-2

    Science.gov (United States)

    Kudlac, M. T.; Weaver, H. F.; Cmar, M. D.

    2012-04-01

    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 1.3 × 10-4 Pa (1 × 10-6 torr) was achieved. The heat sink provided a uniform temperature environment of approximately 77 K (139°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/m2 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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Data of evolutionary structure change: 1VL8B-2UVDB [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1VL8B-2UVDB 1VL8 2UVD B B VFDLRGRVALVTGGSRGLGFGIAQGLAEAGCSVVVASRN...>GLU CA 241 ALA CA 324 SER CA 282 2UV...D B 2UVDB VNYAGNEQKAN 2.647510051727295 1 2UV...D B 2UVDB EIKKL-GSDAI

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

    Science.gov (United States)

    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...

  2. 26 CFR 1.668(b)-2 - Illustration of the provisions of subpart D.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Illustration of the provisions of subpart D. 1.668(b)-2 Section 1.668(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Taxable Years Beginning Before January 1, 1969 § 1.668(b)-2 Illustration of the provisions of subpart...

  3. Reactor Vessel Surveillance Program for Advanced Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyeong-Hoon; Kim, Tae-Wan; Lee, Gyu-Mahn; Kim, Jong-Wook; Park, Keun-Bae; Kim, Keung-Koo

    2008-10-15

    This report provides the design requirements of an integral type reactor vessel surveillance program for an integral type reactor in accordance with the requirements of Korean MEST (Ministry of Education, Science and Technology Development) Notice 2008-18. This report covers the requirements for the design of surveillance capsule assemblies including their test specimens, test block materials, handling tools, and monitors of the surveillance capsule neutron fluence and temperature. In addition, this report provides design requirements for the program for irradiation surveillance of reactor vessel materials, a layout of specimens and monitors in the surveillance capsule, procedures of installation and retrieval of the surveillance capsule assemblies, and the layout of the surveillance capsule assemblies in the reactor.

  4. Thermoelastic properties of ScB2, TiB2, YB4 and HoB4: Experimental and theoretical studies

    DEFF Research Database (Denmark)

    Waśkowska, A.; Gerward, Leif; Staun Olsen, J.

    2011-01-01

    High-pressure X-ray diffraction in ScB2, TiB2, YB4 and HoB4 powders and single crystals has been studied using synchrotron radiation as well as conventional X-rays. The experimental results are supported by calculations using density functional theory. ScB2, YB4 and HoB4 are hard materials (bulk...... modulus 180–200 GPa), while TiB2 may be classified as superhard (bulk modulus about 260 GPa). We report here first experimental and theoretical determinations of the bulk modulus for HoB4 (195(5) and 198.2 GPa, respectively), and first experimental values of the bulk modulus for ScB2 (196(2) GPa) and YB4...

  5. LETTER TO THE EDITOR: Unique Fermi surfaces with quasi-one-dimensional character in CeRh3B2 and LaRh3B2

    Science.gov (United States)

    Okubo, T.; Yamada, M.; Thamizhavel, A.; Kirita, S.; Inada, Y.; Settai, R.; Harima, H.; Takegahara, K.; Galatanu, A.; Yamamoto, E.; Onuki, Y.

    2003-11-01

    We have carried out de Haas-van Alphen (dHvA) experiments on a ferromagnet CeRh3B2 with an extremely high Curie temperature T_{\\mathrm {C}} \\simeq 120 K and a non-4f reference compound LaRh3B2. The dHvA data of LaRh3B2 are well explained by the results of energy band calculations. The topology of the Fermi surfaces in CeRh3B2 is found to be very similar to that of LaRh3B2, possessing wavy but flat Fermi surfaces in the basal plane. Observation of a quasi-one-dimensional electronic state is the first such case in a rare earth compound.

  6. Vortex phase diagram studies in the weakly pinned single crystals of YNi2B2C and LuNi2B2C

    Indian Academy of Sciences (India)

    D Jaiswal-Nagar; D Pal; M R Eskildsen; P C Canfield; H Takeya; S Ramakrishnan; A K Grover

    2006-01-01

    We present a study of magnetization measurements performed on the single crystals of YNi2B2C and LuNi2B2C. For both the compounds, we find flux jumps in magnetisation values in the respective field regions, where the structural transitions in the flux line lattice symmetry have been reported in these systems via the small angle neutron scattering experiments. The magnetisation hysteresis loops and the AC susceptibility measurements show pronounced peak effect as well as second magnetisation peak anomaly for both YNi2B2C and LuNi2B2C. Based on these results, a vortex phase diagram has been constructed for YNi2B2C for $H \\Arrowvert c$ depicting different glassy phases of the vortex matter.

  7. Doping effects of ZrC and ZrB2 in the powder-in-tube processed MgB2 tapes

    Institute of Scientific and Technical Information of China (English)

    MA Yanwei

    2006-01-01

    We have investigated the effects of ZrC and ZrB2 doping on the superconducting properties of the powder-in-tube processed MgB2/Fe tapes. Samples were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM/EDX), transport and magnetic measurements. We confirmed the following quite different roles of ZrC and ZrB2 in MgB2.ZrC doping was found to decrease the transport critical current density (Jc) at 4.2 K, while the critical temperature (Tc) kept constant. In contrast, the Jc values in magnetic fields were enhanced greatly by the ZrB2 addition, which resulted in a decrease in Tc by only 0.5 K. The reason for different effects of two dopants is also discussed.

  8. Characterization and Evaluation of TiB2-AlN Composites for Armor Applications

    Science.gov (United States)

    2013-09-01

    titanium diboride (TiB2) and aluminum nitride (AlN) of varying compositions were consolidated by hot pressing. The compositions examined were 30-vol% TiB2...ceramic composite of titanium diboride (TiB2) and aluminum nitride (AlN) was chosen to be evaluated. TiB2 has been reported (3) to have high...showed some oxygen, which could be surface contamination , and sulfur impurities. 5 Figure 1. XRD spectrum of TiB2 powder. Figure 2

  9. ErbB2 signaling at the crossing between heart failure and cancer

    OpenAIRE

    Vermeulen, Zarha; Segers, Vincent F.M.; De Keulenaer, Gilles W.

    2016-01-01

    The dual role of ErbB2 (or HER-2) in tumor growth and in physiological adaptive reactions of the heart positions ErbB2 at the intersection between cancer and chronic heart failure. Accordingly, ErbB2-targeted inhibitory therapy of cancer may lead to ventricular dysfunction, and activation of ErbB2 for heart failure therapy may induce malignancy. The molecular processes leading to the activation of ErbB2 in tumors and cardiac cells are, however, fundamentally different from each other. Thus, i...

  10. SNTP program reactor design

    Science.gov (United States)

    Walton, Lewis A.; Sapyta, Joseph J.

    1993-06-01

    The Space Nuclear Thermal Propulsion (SNTP) program is evaluating the feasibility of a particle bed reactor for a high-performance nuclear thermal rocket engine. Reactors operating between 500 MW and 2,000 MW will produce engine thrusts ranging from 20,000 pounds to 80,000 pounds. The optimum reactor arrangement depends on the power level desired and the intended application. The key components of the reactor have been developed and are being tested. Flow-to-power matching considerations dominate the thermal-hydraulic design of the reactor. Optimal propellant management during decay heat cooling requires a three-pronged approach. Adequate computational methods exist to perform the neutronics analysis of the reactor core. These methods have been benchmarked to critical experiment data.

  11. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  12. Hybrid reactors. [Fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W.

    1980-09-09

    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 /sup 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/sup -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.

  13. Efficient generation of B2m-null pigs via injection of zygote with TALENs

    Science.gov (United States)

    Wang, Yong; Du, Yinan; Zhou, Xiaoyang; Wang, Lulu; Li, Jian; Wang, Fengchao; Huang, Zhengen; Huang, Xingxu; Wei, Hong

    2016-01-01

    Donor major histocompatibility complex class I (MHC I) molecules are the main targets of the host immune response after organ allotransplantation. Whether and how MHC I-deficiency of pig donor tissues affects rejection after xenotransplantation has not been assessed. Beta2-microglobulin (B2M) is indispensable for the assembly of MHC I receptors and therefore provides an effective target to disrupt cell surface MHC I expression. Here, we report the one-step generation of mutant pigs with targeted disruptions in B2m by injection of porcine zygotes with B2m exon 2-specific TALENs. After germline transmission of mutant B2m alleles, we obtained F1 pigs with biallelic B2m frameshift mutations. F1 pigs lacked detectable B2M expression in tissues derived from the three germ layers, and their lymphocytes were devoid of MHC I surface receptors. Skin grafts from B2M deficient pigs exhibited remarkably prolonged survival on xenogeneic wounds compared to tissues of non-mutant littermates. Mutant founder pigs with bi-allelic disruption in B2m and B2M deficient F1 offspring did not display visible abnormalities, suggesting that pigs are tolerant to B2M deficiency. In summary, we show the efficient generation of pigs with germline mutations in B2m, and demonstrate a beneficial effect of donor MHC I-deficiency on xenotransplantation. PMID:27982048

  14. Global renal gene expression profiling analysis in B2-kinin receptor null mice: impact of diabetes.

    Directory of Open Access Journals (Sweden)

    Miran A Jaffa

    Full Text Available Diabetic nephropathy (DN, the leading cause of end-stage renal failure, is clinically manifested by albuminuria and a progressive decline in glomerular filtration rate. The risk factors and mechanisms that contribute to the development and progression of DN are still incompletely defined. To address the involvement of bradykinin B(2-receptors (B(2R in DN, we used a genome wide approach to study the effects of diabetes on differential renal gene expression profile in wild type and B(2R knockout (B(2R(-/- mice. Diabetes was induced with streptozotocin and plasma glucose levels and albumin excretion rate (AER were measured at predetermined times throughout the 23 week study period. Longitudinal analysis of AER indicated that diabetic B(2R(-/-D null mice had a significantly decreased AER levels compared to wild type B(2R(+/+D mice (P = 0.0005. Results from the global microarray study comparing gene expression profiles among four groups of mice respectively: (B(2R(+/+C, B(2R(+/+D, B(2R(-/-C and B(2R(-/-D highlighted the role of several altered pathological pathways in response to disruption of B(2R and to the diabetic state that included: endothelial injury, oxidative stress, insulin and lipid metabolism and inflammatory process with a marked alteration in the pro-apoptotic genes. The findings of the present study provide a global genomics view of biomarkers that highlight the mechanisms and putative pathways involved in DN.

  15. BPO4@B2O3 and (BPO4@B2O3):Eu3+: The novel single-emitting-component phosphors for near UV-white LEDs

    Science.gov (United States)

    Cao, Xiyu; Liu, Wei; Jiang, Yu; Cao, Lixin; Su, Ge; Gao, Rongjie

    2016-08-01

    Nowadays much effort has been devoted to exploring novel luminescent materials with low-cost, high stability and excellent luminescent properties. In this paper, a new kind of luminescent material BPO4@B2O3 was prepared by using a facile method. The as-obtained samples contain numerous BPO4 nanoparticles enclosed by amorphous and crystalline B2O3 homogeneously, which exhibits a broad emission band ranging from 380 to 700 nm under near-UV irradiation. More importantly, it is worth noting that the BPO4@B2O3 phosphor exhibits the excellent thermal quenching property, which endows it with a promising prospect as phosphors for high power white LEDs. To further promote its application as white light phosphors, Eu3+ ions were doped into the BPO4@B2O3 samples and prepared the (BPO4@B2O3):Eu3+ phosphors with chromaticity coordinates (0.3022, 0.3122). The corresponding packaging of LEDs indicates that both BPO4@B2O3 and (BPO4@B2O3):Eu3+ can be considered as the promising phosphors for WLEDs.

  16. Magnetic and Transport Studies in LaxGd1-xRh3B2 and CexGd1-xRh3B2

    Science.gov (United States)

    Vaidya, Ulhas; Dhar, S. K.; Thamizhavel, A.; Ramakrishnan, S.; Grover, A. K.

    2010-03-01

    The nonmagnetic rare earth ternary boride LaRh3B2, a hexagonal system of space group P6/mmm with CeCo3B2 type structure, is known to superconduct below Tc(0)˜ 2.7 K. When doped with Gd the Tc(0) reduces and no superconductivity is observed above 1.2 K with more than 15% (atomic) doping. The alloys, La0.8Gd0.2Rh3B2 and La0.6Gd0.4Rh3B2 show a jump at ˜ 70 K and rapid rise in magnetization below 10 K. However, no peaks are observed in at these temperatures in AC susceptibility which would have indicated magnetic ordering of the system. It is worth noting that GdRh3B2 orders ferromagnetically at ˜ 93 K. We shall present results of our investigations, above 2 K, in magnetic and transport properties of polycrystalline specimens LaxGd1-xRh3B2 (0 CeRh3B2 is a ferromagnet with Tc ˜ 115 K. The results of Gd doping in this reveal the survival of antiferromagnetic coupling between Ce and Gd spins.

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

    Science.gov (United States)

    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.

  18. Secretion of SerpinB2 from endothelial cells activated with inflammatory stimuli

    Energy Technology Data Exchange (ETDEWEB)

    Boncela, Joanna; Przygodzka, Patrycja [Institute of Medical Biology, Polish Academy of Sciences, Lodz (Poland); Wyroba, Elzbieta [Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw (Poland); Papiewska-Pajak, Izabela [Department of Molecular and Medical Biophysics, Medical University of Lodz (Poland); Cierniewski, Czeslaw S., E-mail: czeslaw.cierniewski@umed.lodz.pl [Institute of Medical Biology, Polish Academy of Sciences, Lodz (Poland); Department of Molecular and Medical Biophysics, Medical University of Lodz (Poland)

    2013-05-01

    Due to the lack of an N-terminal signal peptide, SerpinB2 (plasminogen activator inhibitor type 2) accumulates in cells and only a small percentage of it is secreted. The extracellular concentration of SerpinB2 significantly increases during inflammation. In the present study we investigated the mechanism with which SerpinB2 can be secreted from endothelial cells activated with LPS. We evaluated the intracellular distribution of SerpinB2 by double immunogold labeling followed by a high resolution electron microscopy analysis. We found that SerpinB2 gathers in the vesicular structures and in the endothelial cell periphery. These vesicles stained positive for the trans-Golgi network marker TGN46, which is consistent with their formation by the endoplasmatic reticulum (ER) and Golgi-dependent pathways. SerpinB2 was delivered to the plasma membrane, apparently together with TGN46 in the same vesicles, which after fusion with the membranes released cargo. Secretion of SerpinB2 was partially inhibited by brefeldin A. The secreted SerpinB2 was predominantly in its nonglycosylated 43 kDa form as evaluated by Western immunoblotting. Our data suggest that increased expression of SerpinB2 by an inflammatory stimulus is sufficient to generate structures that resemble secretory vesicles. These vesicles may represent the mechanism by which high local concentrations of SerpinB2 are released at inflammation sites from endothelial cells. - Highlights: ► LPS stimulates generation of secretory vesicles containing SerpinB2. ► SerpinB2 concentrates in TGN46 positive vesicles close to the plasma membrane. ► Brefeldin A inhibits secretion of SerpinB2. ► The secreted SerpinB2 was predominantly in its nonglycosylated 43 kDa.

  19. Multi purpose research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Raina, V.K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)]. E-mail: vkrain@magnum.barc.ernet.in; Sasidharan, K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sengupta, Samiran [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Singh, Tej [Research Reactor Services Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2006-04-15

    At present Dhruva and Cirus reactors provide the majority of research reactor based facilities to cater to the various needs of a vast pool of researchers in the field of material sciences, physics, chemistry, bio sciences, research and development work for nuclear power plants and production of radio isotopes. With a view to further consolidate and expand the scope of research and development in nuclear and allied sciences, a new 20 MWt multi purpose research reactor is being designed. This paper describes some of the design features and safety aspects of this reactor.

  20. INVAP's Research Reactor Designs

    Directory of Open Access Journals (Sweden)

    Eduardo Villarino

    2011-01-01

    Full Text Available INVAP, an Argentine company founded more than three decades ago, is today recognized as one of the leaders within the research reactor industry. INVAP has participated in several projects covering a wide range of facilities, designed in accordance with the requirements of our different clients. For complying with these requirements, INVAP developed special skills and capabilities to deal with different fuel assemblies, different core cooling systems, and different reactor layouts. This paper summarizes the general features and utilization of several INVAP research reactor designs, from subcritical and critical assemblies to high-power reactors.

  1. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, Mitsuru

    1997-04-04

    An LMFBR type reactor comprises a plurality of reactor cores in a reactor container. Namely, a plurality of pot containing vessels are disposed in the reactor vessel and a plurality of reactor cores are formed in a state where an integrated-type fuel assembly is each inserted to a pot, and a coolant pipeline is connected to each of the pot containing-vessel to cool the reactor core respectively. When fuels are exchanged, the integrated-type fuel assembly is taken out together with the pot from the reactor vessel in a state where the integrated-type fuel assembly is immersed in the coolants in the pot as it is. Accordingly, coolants are supplied to each of the pot containing-vessel connected with the coolant pipeline and circulate while cooling the integrated-type fuel assembly for every pot. Then, when the fuels are exchanged, the integrated type fuel assembly is taken out to the outside of the reactor together with the pot by taking up the pot from the pot-containing vessel. Then, neutron economy is improved to thereby improve reactor power and the breeding ratio. (N.H.)

  2. Spectroscopic and modeling investigations of the gas-phase chemistry and composition in microwave plasma activated B2H6/Ar/H2 mixtures.

    Science.gov (United States)

    Ma, Jie; Richley, James C; Davies, David R W; Cheesman, Andrew; Ashfold, Michael N R; Mankelevich, Yuri A

    2010-02-25

    This paper describes a three-pronged study of microwave (MW) activated B(2)H(6)/Ar/H(2) plasmas as a precursor to diagnosis of the B(2)H(6)/CH(4)/Ar/H(2) plasmas used for the chemical vapor deposition of B-doped diamond. Absolute column densities of B atoms and BH radicals have been determined by cavity ring-down spectroscopy as a function of height (z) above a molybdenum substrate and of the plasma process conditions (B(2)H(6) and Ar partial pressures, total pressure, and supplied MW power). Optical emission spectroscopy has been used to explore variations in the relative densities of electronically excited BH, H, and H(2) species as a function of the same process conditions and of time after introducing B(2)H(6) into a pre-existing Ar/H(2) plasma. The experimental measurements are complemented by extensive 2-D(r, z) modeling of the plasma chemistry, which results in refinements to the existing B/H chemistry and thermochemistry and demonstrates the potentially substantial loss of gas-phase BH(x) species through reaction with trace quantities of air/O(2) in the process gas mixture and heterogeneous processes occurring at the reactor wall.

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

    Science.gov (United States)

    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.

  4. B2C电子商务市场的逆向物流分析%Analysis on Reverse Logistic in B2C Electronic Commerce Market

    Institute of Scientific and Technical Information of China (English)

    刘田; 牟援朝

    2006-01-01

    讨论B2C电子商务市场中的逆向物流问题,以期能够在人们研究逆向物流这一问题之时,与当前的电子商务市场加以结合.从逆向物流的定义谈起,结合B2C电子商务市场的特点,分析了如何进行B2C电子商务市场中逆向物流的管理.

  5. A report on how foreign trade enterprises use B2B platform%外贸B2B平台使用调查

    Institute of Scientific and Technical Information of China (English)

    李冠艺

    2010-01-01

    @@ 为帮助外贸企业更好地选择外贸B2B平台所提供的服务,用好外贸B2B平台,提高使用效果,2010年5月,我们针对全国的外贸企业进行了网络抽样调查,根据调查结果形成此外贸B2B平台使用调查报告.

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

    Science.gov (United States)

    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

    2014-10-21

    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.

  7. Secretion of SerpinB2 from endothelial cells activated with inflammatory stimuli.

    Science.gov (United States)

    Boncela, Joanna; Przygodzka, Patrycja; Wyroba, Elzbieta; Papiewska-Pajak, Izabela; Cierniewski, Czeslaw S

    2013-05-01

    Due to the lack of an N-terminal signal peptide, SerpinB2 (plasminogen activator inhibitor type 2) accumulates in cells and only a small percentage of it is secreted. The extracellular concentration of SerpinB2 significantly increases during inflammation. In the present study we investigated the mechanism with which SerpinB2 can be secreted from endothelial cells activated with LPS. We evaluated the intracellular distribution of SerpinB2 by double immunogold labeling followed by a high resolution electron microscopy analysis. We found that SerpinB2 gathers in the vesicular structures and in the endothelial cell periphery. These vesicles stained positive for the trans-Golgi network marker TGN46, which is consistent with their formation by the endoplasmatic reticulum (ER) and Golgi-dependent pathways. SerpinB2 was delivered to the plasma membrane, apparently together with TGN46 in the same vesicles, which after fusion with the membranes released cargo. Secretion of SerpinB2 was partially inhibited by brefeldin A. The secreted SerpinB2 was predominantly in its nonglycosylated 43kDa form as evaluated by Western immunoblotting. Our data suggest that increased expression of SerpinB2 by an inflammatory stimulus is sufficient to generate structures that resemble secretory vesicles. These vesicles may represent the mechanism by which high local concentrations of SerpinB2 are released at inflammation sites from endothelial cells.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  9. Reserch and Progress in MgB2 Matrix Superconductive Material%MgB2基超导材料研究进展

    Institute of Scientific and Technical Information of China (English)

    黄勇; 刘心宇; 曾中明

    2003-01-01

    2001年1月发现MgB2基超导体具有39K的临界转变温度。是迄今为止转变温度最高的非铜氧化物超导体。国内外对MgB2基超导材料进行了广泛而又深入的研究,本文简述了近期对MgB2基超导材料的研究进展,介绍了近期主要有关MgB2基超导材料电子结构研究和应用开发的工作。着重叙述了关于基超导机制的研究。

  10. 关于B2B服务品牌忠诚度的研究%A research on brand loyalty of B2B service

    Institute of Scientific and Technical Information of China (English)

    孔令明; 耿禧则

    2012-01-01

    The research on brand loyalty has been confined to the product brand in the past. This paper applied brand loyalty theory to B2B service brand. Through empirical research, this paper reflected the effect of the brand recognition and brand image to action loyalty and attitude loyalty, and put forward some suggestions for the B2B service brand management%对于品牌忠诚度的研究,过去一直局限于产品品牌上。本文将品牌忠诚度理论运用于B2B服务品牌,通过实证调查,研究品牌认知度与品牌形象对态度忠诚度和行动忠诚度的影响作用,并据此为B2B服务品牌的成功管理提出建议。

  11. Observation of b2 symmetry vibrational levels of the SO2 C ˜ 1B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants

    Science.gov (United States)

    Park, G. Barratt; Jiang, Jun; Saladrigas, Catherine A.; Field, Robert W.

    2016-04-01

    The C ˜ 1B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X ˜ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C ˜ state below 1600 cm-1 of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry and to determine accurately the vibrational dependence of the rotational constants in the distorted C ˜ electronic state.

  12. Development and Application of Interatomic Potentials for Ultra High Temperature Ceramics (UHTC): ZrB2 and HfB2

    Science.gov (United States)

    Lawson, John W.; Daw, Murray; Bauschlicher

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 are characterized by high melting point, good strength, and reasonable oxidation resistance. These materials are of interest for use as sharp leading edges for hypersonic vehicles among other applications. Progress in computational modeling of UHTCs has been limited in part due to the absence of suitable interatomic potentials. We present a Tersoff style parameterization of such potentials for ZrB2 and HfB2 appropriate for atomistic simulations. Parameters are fit to data generated from ab initio calculations. The accuracy of the potentials is assessed against further ab initio data. As a first non ]trivial application, molecular dynamics simulations are performed to evaluate the thermal conductivity of single crystals and the thermal resistance of high symmetry grain boundaries.

  13. Observation of b2 symmetry vibrational levels of the SO2 C̃ (1)B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants.

    Science.gov (United States)

    Park, G Barratt; Jiang, Jun; Saladrigas, Catherine A; Field, Robert W

    2016-04-14

    The C̃ (1)B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X̃ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C̃ state below 1600 cm(-1) of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry and to determine accurately the vibrational dependence of the rotational constants in the distorted C̃ electronic state.

  14. Growth of MgB2 Thin Films by Chemical Vapour Deposition Using B2H6 as a boron Source

    Institute of Scientific and Technical Information of China (English)

    王淑芳; 朱亚彬; 刘震; 周岳亮; 张芹; 陈正豪; 吕惠宾; 杨国桢

    2003-01-01

    Superconducting MgB2 thin films were grown on single crystal Al2O3 (0001) by chemical vapour deposition using B2H6 as a boron source. MgB2 film was then accomplished by annealing the boron precursor films in the presence of high-purity magnesium bulk at 890℃ in vacuum. The as-grown MgB2 films are smooth and c-axis-oriented.The films exhibit a zero-resistance transition of about 38K with a narrow transition width of 0.2 K. Magnetic hysteresis measurements yield the critical current density of 1.9 × 107 A/cm2 at 10 K in zero field.

  15. B2B电子商务协作模型研究%Research on B2B Electronic Business Collaboration Model

    Institute of Scientific and Technical Information of China (English)

    李双庆; 程代杰; 何玲

    2003-01-01

    B2B is an important application form in electronic business, it provides the methods to do business activities through Internet among companies. But the heterogeneous of the information systems between companies makes it difficult in interoperating between them. In this paper, a B2B electronic business collaboration model is proposed, solving the collaboration between heterogeneous business systems by defining the business irformation ontology and describing the hierarchy in business collaboration process.

  16. Oxidation Resistance of ZrB2-SiC Multilayer Ceramics%ZrB2–SiC多层陶瓷的抗氧化性

    Institute of Scientific and Technical Information of China (English)

    左凤娟; 成来飞; 张立同

    2012-01-01

    ZrB2-SiC multilayer ceramic was prepared by a coneventional ceramic tape casting technology. The density was measured using the Archimede method. The microstructure of samples was observed by scanning electron microscopy. The oxidation resistance ofZrB2-SiC multilayer ceramics was also determined. The results indicate that for the product sintered at 1 950 ℃, the relative density is 99.7%. During the oxidation process of this material, the low melting phase is firstly volatilized, and then the oxidation layer is formed, which can diminish the further oxidation. The oxidation resistance of ZrB2-SiC multilayer ceramic was better than that of ZrB2-SiC monolithic ceramics.%用传统陶瓷的流延工艺制备ZrB2–SiC多层陶瓷。用Archimedes法测定ZrB2–SiC多层陶瓷的相对密度。用扫描电子显微镜观察其显微结构,并进行循环抗氧化性能评价。结果表明:ZrB2–SiC多层陶瓷在1 950℃烧结的致密度达到99.7%,材料的抗氧化过程主要可分为两个阶段:第一阶段低熔点相的挥发,出现质量损失;第二阶段氧化层的形成,降低进一步氧化速率。抗氧化性能较ZrB2–SiC复相陶瓷有很大提高。

  17. Advance in Research of TiB2 Materials%TiB2材料的研究现状

    Institute of Scientific and Technical Information of China (English)

    李苏; 李俊寿; 赵芳; 张颖

    2013-01-01

    TiB2材料作为一种新型先进材料,由于具有强度高、硬度高、耐磨损、耐腐蚀、熔点高、蒸气压低、导电性良好等优点而被广泛研究.介绍了TiB2材料的晶体结构与性质及其制备方法,包括直接合成法、碳热法、镁热法、溶胶-凝胶法、化学气相沉积法等,并分析总结了TiB2材料的致密化、涂层、复相陶瓷、微纳米结构等应用研究热点.其中,将两种或多种方法结合起来制备TiB2,已成为降低成本、减少污染、优化性能的重要途径.%As advanced materials, TiB2 materials have been widely studied because of their good properties,such as high strength,high hardness, wear resistance,corrosion resistance,high melting point,low vapor pressure,good electrical conductivity and so on. The crystal structural properties and preparation methods of TiB2 materials are introduced, such as direct synthesis, carbon thermal method, magnesium thermal method, sol-gel method, chemical vapor deposition method and so oa The reviews on densification, coating,multiphase ceramics and micro-nano structure of TiB2 materials are given as the research hotspots. Combining with two or more methods to synthesize TiB2 has been an important way of cost down, pollution reduction and performance optimization

  18. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  19. Space Nuclear Reactor Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-06

    We needed to find a space reactor concept that could be attractive to NASA for flight and proven with a rapid turnaround, low-cost nuclear test. Heat-pipe-cooled reactors coupled to Stirling engines long identified as the easiest path to near-term, low-cost concept.

  20. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2001-04-01

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  1. Research Progress of Doping in MgB2 Superconducting Material%MgB2超导材料掺杂研究进展

    Institute of Scientific and Technical Information of China (English)

    付尧; 张松; 吴燕平; 邓朝勇

    2013-01-01

    元素掺杂可以提升MgB2在磁场中的性能,解决其超导性能在磁场环境下的退化问题,对MgB2超导材料的应用具有重大意义.介绍了元素掺杂MgB2的目的及作用机理,从薄膜、块材、线带材3个方面具体综述了纳米SiC和有机物掺杂MgB2超导体的研究进展,系统总结了烧结温度及有机物掺杂量对MgB2超导体的性能影响,深入分析了有机物掺杂改善MgB2超导性能的微观原因.

  2. Research on B2C Buying Online Mode%基于B2C的网络团购模式研究

    Institute of Scientific and Technical Information of China (English)

    王晓燕

    2011-01-01

    Purchasing online trade is seen more and more frequently in our country since the beginning of 21st century, and a large quantity of B2C websites for purchasing online have appeared. The factors influencing purchasing online are bargaining space, buyer expectation, competitive situation and so on. All of these factors play a decisive role for B2C purchasing online mode. Summing up the development of various purchasing online modes, eight B2C purchasing online modes can be divided from the three latitudes of sponsors, diversity of products and the number of buyers.%我国从21世纪以来网络团购交易越来越频繁,出现了大批的B2C网络团购网站。影响网络团购的因素有议价空间、买方预期、竞争状况等,这些因素对于B2C网络团购模式都有决定性的作用,总结多种团购模式发现,较为稳定的八种B2C网络团购模式都可从发起者、产品的多样性及卖家数量三个维度来进行划分。

  3. Study of TiB2 Ceramics via SHS/PHIP%SHS/PHIP法合成TiB2陶瓷的研究

    Institute of Scientific and Technical Information of China (English)

    徐强; 张幸红; 曲伟; 韩杰才

    2002-01-01

    采用自蔓延高温合成结合准热等静压(SHS/PHIP)工艺制备了TiB2陶瓷材料,并进行了X射线衍射(XRD)、扫描电镜(SEM)、力学性能等实验研究.XRD结果表明反应生成了高纯度的TiB2,没有其他相生成,这与热力学计算结果相吻合.材料SEM分析发现,TiB2陶瓷颗粒形貌为近等轴状,尺寸细小且较均匀,在TiB2陶瓷颗粒间还存在"烧结颈",由于SHS反应所产生的高温,造成了TiB2陶瓷颗粒表面的圆化.合成产物的致密度较低,气孔主要存在于TiB2陶瓷颗粒交界处,较低的致密性导致了材料具有较低的硬度、弯曲强度和断裂韧性等力学性能.

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

    Science.gov (United States)

    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).

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

    Science.gov (United States)

    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.

  6. Critical current density and flux pinning in Zr0.96V0.04B2 superconductor with AlB2 structure

    Science.gov (United States)

    Jung, Soon-Gil; Vanacken, J.; Moshchalkov, V. V.; Renosto, S. T.; dos Santos, C. A. M.; Machado, A. J. S.; Fisk, Z.; Albino Aguiar, J.

    2013-10-01

    We have investigated the critical current density (Jc) and the flux pinning behavior in Zr0.96V0.04B2 superconductor with an AlB2 structure. V substitutions in Zr sites of non-superconducting ZrB2 system lead to superconductivity, and the 4% V-substituted Zr0.96V0.04B2 compounds show the highest superconducting transition temperature (Tc) of ˜8.7 K. The magnetic hysteresis (M-H) loops for the Zr0.96V0.04B2 demonstrate type-II superconducting behavior in a broad temperature range, and the Jc is estimated from the M-H loops using the Bean model. The analysis of the double-logarithmic Jc(H) plots indicates the dominance of collective pinning in Zr0.96V0.04B2, and that Jc(H) and magnetic field dependences of the flux pinning force density (Fp) are well fitted by the double exponential model which takes into account the existence of two superconducting gaps.

  7. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  8. Status of French reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ballagny, A. [Commissariat a l`Energie Atomique, Saclay (France)

    1997-08-01

    The status of French reactors is reviewed. The ORPHEE and RHF reactors can not be operated with a LEU fuel which would be limited to 4.8 g U/cm{sup 3}. The OSIRIS reactor has already been converted to LEU. It will use U{sub 3}Si{sub 2} as soon as its present stock of UO{sub 2} fuel is used up, at the end of 1994. The decision to close down the SILOE reactor in the near future is not propitious for the start of a conversion process. The REX 2000 reactor, which is expected to be commissioned in 2005, will use LEU (except if the fast neutrons core option is selected). Concerning the end of the HEU fuel cycle, the best option is reprocessing followed by conversion of the reprocessed uranium to LEU.

  9. Fast creation of dense MgB2 phase in wires made by IMD process

    Science.gov (United States)

    Kováč, P.; Hušek, I.; Melišek, T.; Kopera, L.; Kulich, M.

    2016-10-01

    Single-core MgB2 wires have been made by internal magnesium diffusion (IMD) into boron process. Heat treatments were performed at variable periods (4-90 min) for two adjusted temperatures 635 °C and 650 °C, with an overshoot of ≈20 °C after 5 min. Critical currents of differently treated MgB2/Ti/GlidCop wires have been measured and related with the MgB2 layers. The fast creation MgB2 compound has been observed after 8 min annealing at both temperatures and showing the critical current maxima. The less uniform MgB2 containing cracks was created for longer annealing periods (≥10 min), which resulted in lowered critical currents and worsened thermal stability. The fast creation of dense MgB2 allows it to utilize a continual and short heat treatment process for high current density wires made by IMD.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Improvement of skin wound healing in diabetic mice by kinin B2 receptor blockade.

    Science.gov (United States)

    Desposito, Dorinne; Chollet, Catherine; Taveau, Christopher; Descamps, Vincent; Alhenc-Gelas, François; Roussel, Ronan; Bouby, Nadine; Waeckel, Ludovic

    2016-01-01

    Impaired skin wound healing is a major medical problem in diabetic subjects. Kinins exert a number of vascular and other actions limiting organ damage in ischaemia or diabetes, but their role in skin injury is unknown. We investigated, through pharmacological manipulation of bradykinin B1 and B2 receptors (B1R and B2R respectively), the role of kinins in wound healing in non-diabetic and diabetic mice. Using two mouse models of diabetes (streptozotocin-induced and db/db mice) and non-diabetic mice, we assessed the effect of kinin receptor activation or inhibition by subtype-selective pharmacological agonists (B1R and B2R) and antagonist (B2R) on healing of experimental skin wounds. We also studied effects of agonists and antagonist on keratinocytes and fibroblasts in vitro. Levels of Bdkrb1 (encoding B1R) and Bdkrb2 (encoding B2R) mRNAs increased 1-2-fold in healthy and wounded diabetic skin compared with in non-diabetic skin. Diabetes delayed wound healing. The B1R agonist had no effect on wound healing. In contrast, the B2R agonist impaired wound repair in both non-diabetic and diabetic mice, inducing skin disorganization and epidermis thickening. In vitro, B2R activation unbalanced fibroblast/keratinocyte proliferation and increased keratinocyte migration. These effects were abolished by co-administration of B2R antagonist. Interestingly, in the two mouse models of diabetes, the B2R antagonist administered alone normalized wound healing. This effect was associated with the induction of Ccl2 (encoding monocyte chemoattractant protein 1)/Tnf (encoding tumour necrosis factor α) mRNAs. Thus stimulation of kinin B2 receptor impairs skin wound healing in mice. B2R activation occurs in the diabetic skin and delays wound healing. B2R blockade improves skin wound healing in diabetic mice and is a potential therapeutic approach to diabetic ulcers.

  12. Do self-service technologies affect interfirm relationships? A B2B perspective

    OpenAIRE

    Raechel Johns

    2014-01-01

    While considerable literature examines business-to business (B2B) relationships, the impact of technology on these relationships has lacked attention. IT has impacted the way businesses operate in a B2B context as well as influencing services by altering the way services are delivered. To understand the way in which Internet technology has impacted these B2B services, it is essential to examine its impact not only on business processes but on business relationships too. One technology, enable...

  13. ZrB2-TiB2 composite coating on surface of copper electrode by electrospark deposition%铜电极表面电火花沉积ZrB2-TiB2复相涂层

    Institute of Scientific and Technical Information of China (English)

    杨李安卓; 董仕节; 罗平; 孙世烜; 杨巍; 刘琪

    2015-01-01

    采用粉末冶金法制备ZrB2-TiB2复相材料熔敷棒,并通过电火花沉积工艺在铜电极表面制备ZrB2-TiB2复相涂层.通过扫描电镜结合能谱分析研究了涂层的显微结构和元素分布,利用X射线衍射和显微硬度测试对涂层的物相组成与显微硬度进行检测.结果表明:直接熔敷ZrB2-TiB2复相涂层致密性较差,且存在较多裂纹,与基体有明显分层,涂层物相为Cu、ZrB2和TiB2;在预沉积Ni层(Ni层)上后沉积ZrB2-TiB2,所得的多层涂层具有较好的致密性,且涂层与基体间无分层;中间层有Ti、Zr、Cu元素的扩散,说明涂层与基体为冶金结合;ZrB2-TiB2复相涂层硬度为900 HV0.05稍高于多层涂层硬度(800 HV0.05).

  14. A role of nesfatin-1/NucB2 in dehydration-induced anorexia.

    Science.gov (United States)

    Yoshimura, Mitsuhiro; Matsuura, Takanori; Ohkubo, Junichi; Maruyama, Takashi; Ishikura, Toru; Hashimoto, Hirofumi; Kakuma, Tetsuya; Mori, Masatomo; Ueta, Yoichi

    2014-07-15

    Nesfatin-1/NucB2, an anorexigenic molecule, is expressed mainly in the hypothalamus, particularly in the supraoptic nucleus (SON) and the paraventricular nucleus (PVN). Nesfatin-1/NucB2 is also expressed in the subfornical organ (SFO). Because the SON and PVN are involved in body fluid regulation, nesfatin-1/NucB2 may be involved in dehydration-induced anorexia. To clarify the effects of endogenous nesfatin-1/NucB2, we studied changes in nesfatin-1/NucB2 mRNA levels in the SFO, SON, and PVN in adult male Wistar rats after exposure to osmotic stimuli by using in situ hybridization histochemistry. Significant increases in nesfatin-1/NucB2 mRNA levels, ∼2- to 3-fold compared with control, were observed in the SFO, SON, and PVN following water deprivation for 48 h, consumption of 2% NaCl hypertonic saline in drinking water for 5 days, and polyethylene glycol-induced hypovolemia. In addition, nesfatin-1/NucB2 expression was increased in response to water deprivation in a time-dependent manner. These changes in nesfatin-1/NucB2 mRNA expression were positively correlated with plasma sodium concentration, plasma osmolality, and total protein levels in all of the examined nuclei. Immunohistochemistry for nesfatin-1/NucB2 revealed that nesfatin-1/NucB2 protein levels were also increased after 48 h of dehydration and attenuated by 24 h of rehydration. Moreover, intracerebroventricular administration of nesfatin-1/NucB2-neutralizing antibody after 48 h of water deprivation resulted in a significant increase in food intake compared with administration of vehicle alone. These results suggested that nesfatin-1/NucB2 is a crucial peptide in dehydration-induced anorexia.

  15. erbB2 is required for G protein-coupled receptor signaling in the heart

    OpenAIRE

    Negro, Alejandra; Brar, Bhawanjit K.; Gu, Yusu; Peterson, Kirk L.; Vale, Wylie; Lee, Kuo-Fen

    2006-01-01

    erbB2/Her2, a ligandless receptor kinase, has pleiotropic effects on mammalian development and human disease. The absence of erbB2 signaling in cardiac myocytes results in dilated cardiomyopathy in mice, resembling the cardiotoxic effects observed in a subset of breast cancer patients treated with the anti-Her2 antibody herceptin. Emerging evidence suggests that erbB2 is pivotal for integrating signaling networks involving multiple classes of extracellular signals. However, its role in G prot...

  16. Anomalous magnetism of CeRh3B2 under pressure

    Science.gov (United States)

    Shaheen, S. A.; Schilling, J. S.; Klavins, P.; Vining, C. B.; Shelton, R. N.

    Whereas CeRh3B2 possesses the highest magnetic ordering temperature (T sub c approx. = 115K) of any Ce-compound with nonmagnetic constituents, LaRh3B2 becomes superconducting below 2.5K. Recent magnetization measurements under pressure as well as lattice parameter and specific heat studies shed light on the nature of the anomalous magnetic state in CeRh3B2.

  17. B2B marketingová komunikace společnosti John Deere

    OpenAIRE

    2013-01-01

    The aim of this master's thesis is to evaluate the implementation of the B2B marketing strategy of John Deere on a specific example. The theoretical part of the thesis focuses on defining the basics of modern marketing communications. Next it deals with defining the concept of B2B marketing and related strategies. The practical part focuses on the characterisation of the agricultural machinery industry and the slovak agricultural sector. Further it includes the introduction of other B2B marke...

  18. B2C电子商务服务质量评价研究%Research on Evaluation of Service Quality for B2C E-commerce

    Institute of Scientific and Technical Information of China (English)

    施国洪; 施钟贤

    2013-01-01

    After more than ten years of development, China's network shopping has begun to enter the relative mature stage. Because the current B2C mode of the electronic commerce development is particularly rapid and its market share increase year by year, e-commerce will become the core of the future development and the focus of theoretical research. Related research shows that traditional service quality evaluation models represented by SERVQUAL model for e-commerce service quality evaluation are lack of adequate reliability, so the evaluation research for B2C e-commerce service quality has to be further deepened. This article focuses on the current research on B2C e-commerce service quality. The characteristics and existing problems in these studies are summarized and the future development direction of the B2C e-commerce service quality research is pointed out , in order to improve the service quality and provide reference and help for B2C e-commerce enterprises.%经过十余年的发展,中国的网络购物已经开始步入相对成熟的阶段,当前以B2C模式的电子商务发展尤为迅速,市场份额逐年提高,必将成为未来电子商务发展的核心及理论研究的重点。相关研究表明,以SERVQUAL模型为代表的传统服务质量评价模型对于电子商务服务质量的评价缺乏足够的信度,因此对于B2C电子商务服务质量的评价研究也就有待进一步深化。本文对当前涉及B2C电子商务服务质量的相关研究进行了重点介绍,总结了这些研究的特点以及存在的问题,指出了今后B2C电子商务服务质量的研究需要发展的方向,以期为B2C电子商务企业提高服务质量提供借鉴和帮助。

  19. MgB2材料在超导科学中的研究

    Institute of Scientific and Technical Information of China (English)

    吴尝

    2006-01-01

    2001年,具有39K超导转变温度的MgB2被发现,该发现在科技界引起极大关注.文章就近年来二硼化镁(MgB2)的晶体结构及超导原理,制备温度、压强、过量Mg对MgB2超导电性的影响,MgB2超导体的掺杂效应及制备等方面的研究进展作了阐述.

  20. Isotope Effect on Electron-Phonon Coupling in Multiband Superconductor MgB2

    Science.gov (United States)

    Mou, Daixiang; Taufour, Valentin; Wu, Yun; Huang, Lunan; Bud'Ko, Serguei; Canfield, Paul; Kaminski, Adam

    We systematically investigate the isotope effect of electron-phonon coupling in multi-band superconductor MgB2 by laser based Angle Resolved Photoemission Spectroscopy. The kink structure around 70 meV on two σ bands, which is caused by electron coupling to E2 g phonon mode, is shifted to higher binding energy in Mg10B2 than that in Mg11B2. The measured shifting energy of 3.5 meV is consistent with theoretical calculation based on harmonic phonon in MgB2. Our temperature dependent measurement also indicates the isotope effect of kink structure is not dependent on superconducting transition.

  1. Al-doped MgB2 materials studied using electron paramagnetic resonance and Raman spectroscopy

    Science.gov (United States)

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

    2016-05-01

    Undoped and aluminum (Al) doped magnesium diboride (MgB2) samples were synthesized using a high-temperature solid-state synthesis method. The microscopic defect structures of Al-doped MgB2 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 MgB2. Above a certain level of Al doping, enhanced conductive properties of MgB2 disappear due to filling of vacancies or trapping of Al in Mg-related vacancy sites.

  2. Supercondcuting properties in MgB2/Fe wires prepared by PIT method

    Institute of Scientific and Technical Information of China (English)

    YAN Guo; FENG Yong; FU Baoquan; LIU Chunfang; JI Ping; ZHANG Pingxiang; ZHOU Lian

    2003-01-01

    The MgB2 formation was analyzed physically and chemically and the MgB2/Fe wires were fabricated by powder in tube (PIT) technology. The microstructureof MgB2 in wires was studied by the scanning electrical microscope (SEM), whichshows a good connection of grains and the size of MgB2 grain is 1-3μm. The results of Jc measured by the standard four probes method show that Jc value reaches 6.1×104 A/cm2 at 20 K in self field.

  3. MgB2 superconducting whiskers synthesized by using the hybrid physical-chemical vapor deposition.

    Science.gov (United States)

    Wang, Yazhou; Zhuang, Chenggang; Gao, Jingyun; Shan, Xudong; Zhang, Jingmin; Liao, Zhimin; Xu, Hongjun; Yu, Dapeng; Feng, Qingrong

    2009-02-25

    In this work, MgB(2) whiskers were fabricated on a copper substrate by using the hybrid physical-chemical vapor deposition, which was one of the most effective ways to make high quality pure MgB(2) films, with the possible growth mechanism discussed. The whiskers are hexagonal and conelike and grow along the [0001] direction with a single-crystal structure. The onset transition temperature is approximately 39 K, which is among the best in the published nanostructure MgB(2) papers. Fabrication of nanoscale MgB(2) whiskers provides the fundamental understanding of the effect of dimensionality and size on superconductivity.

  4. Superconducting MgB2 flowers: growth mechanism and their superconducting properties

    Science.gov (United States)

    Seong, Won Kyung; Ranot, Mahipal; Lee, Ji Yeong; Yang, Cheol-Woong; Lee, Jae Hak; Oh, Young Hoon; Ahn, Jae-Pyoung; Kang, Won Nam

    2016-04-01

    We report for the first time the growth and the systematic study of the growth mechanism for flower-like MgB2 structures fabricated on the substrates for solid-state electronics by the hybrid physical-chemical vapor deposition (HPCVD) technique. The MgB2 flower has a width of 30 μm and a height of 10 μm. The superconductivity of MgB2 flowers was confirmed by a magnetization measurement, and the transition temperature is 39 K, which is comparable with high-quality bulk samples. The excellent current-carrying capability was demonstrated by MgB2 flowers. To understand the nucleation and growth mechanism of MgB2 flowers a very systematic study was performed by a high-resolution transmission electron microscope (HRTEM) and atom probe (AP) microscopy. The HRTEM revealed that the seed grain of a MgB2 flower has a [101¯0] direction, and the flower is composed of micro-columnar MgB2 grains having pyramidal tips and which are grown along the (0001) plane. A clear understanding of the growth mechanism for MgB2 flowers could lead to the growth of other low-dimensional MgB2 structures for superconducting electronic devices.

  5. Electrochemical Oxidation of Paracetamol Mediated by MgB2 Microparticles Modified Glassy Carbon Electrode

    OpenAIRE

    Mohammed Zidan; Tan Wee Tee; A. Halim Abdullah; Zulkarnain Zainal; Goh Joo Kheng

    2011-01-01

    A MgB2 microparticles modified glassy carbon electrode (MgB2/GCE) was fabricated by adhering microparticles of MgB2 onto the electrode surface of GCE. It was used as a working electrode for the detection of paracetamol in 0.1 M KH2PO4 aqueous solution during cyclic voltammetry. Use of the MgB2/GCE the oxidation process of paracetamol with a current enhancement significantly by about 2.1 times. The detection limit of this modified electrode was found to be 30 μM. The sensitivity under conditio...

  6. Inhibition of ErbB-2 induces TFF3 downregulation in breast cancer cell lines.

    Science.gov (United States)

    Yue, Lu; Xiang, Jinyu; Shen, Zan; Wang, Zhihao; Yao, Yasai; Zhou, Quan; Ding, Aiping; Qiu, Wensheng

    2014-07-01

    ErbB-2 gene plays an important role in carcinoma formation whose overexpression was observed in many types of tumors, including breast cancer. Dysregulation of Trefoil factor 3 (TFF3), which is thought to function in the development and progression of breast cancer, was found to be upregulated in ErbB2-overexpressing breast cancers and cells. However, a putative interaction between ErbB-2 and TFF3 in breast cancer remains unknown. To determine whether TFF3 has an important role in breast tumor, its levels were measured by immunohistochemistry in 130 cases of breast infiltrating duct carcinoma and 30 cases of normal breast tissue with a specific monoclonal antibody raised against human TFF3. Patients who were positive for ErbB-2 also had high expression levels of TFF3 (p TFF3 by real-time polymerase chain reaction and Western blotting, respectively. Compared with the control groups, ErbB-2 mRNA expression was decreased in the Lenti-ShERBB2 infection group, and Western blotting indicated a concordant ErbB-2 protein reduction. On the other hand, TFF3 expression at both mRNA and protein levels was significantly downregulated by ErbB-2 silencing in SK-BR-3. These findings are a proof of the foundation for a certain relationships of ErbB-2 and TFF3, which may serve as novel therapeutic markers of ErbB2-overexpressing breast cancers in the future.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  8. Slurry reactor design studies

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  9. Gas cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1972-06-01

    Although most of the development work on fast breeder reactors has been devoted to the use of liquid metal cooling, interest has been expressed for a number of years in alternative breeder concepts using other coolants. One of a number of concepts in which interest has been retained is the Gas-Cooled Fast Reactor (GCFR). As presently envisioned, it would operate on the uranium-plutonium mixed oxide fuel cycle, similar to that used in the Liquid Metal Fast Breeder Reactor (LMFBR), and would use helium gas as the coolant.

  10. Microfluidic electrochemical reactors

    Science.gov (United States)

    Nuzzo, Ralph G [Champaign, IL; Mitrovski, Svetlana M [Urbana, IL

    2011-03-22

    A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

  11. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  12. Effects of ZrB2 on substructure and wear properties of laser melted in situ ZrB2p/6061Al composites

    Science.gov (United States)

    Zeng, Yida; Chao, Yuhjin; Luo, Zhen; Cai, Yangchuan; Huang, Yongxian

    2016-03-01

    Aluminum matrix composites reinforced by in situ ZrB2 particles were successfully fabricated from an Al-KBF4-K2ZrF6 system via a direct melt reaction. A laser surface melting strategy is used to improve the surface strength of the in situ ZrB2p/6061Al composite, which includes a series of laser-melted composites with different laser power processed by a 2 kW YAG laser generator. XRD and EDS results demonstrated the existence of ZrB2 nanoparticles in the composite. After laser melting, the penetration depth of the molten pool increases with increasing power density. OM and SEM analysis indicate that the laser melting process yields narrower cellular spacing of the matrix and partly disperses the ZrB2 particle clusters. Compared with laser-melted matrix alloys, the crystal orientations near the melted layers edge of the composite are almost random due to heterogeneous nucleation in the melt and the pinning effect of laser-dispersed ZrB2 nanoparticles at the solidification front. Wear test results show that the laser melted layer performs better at wear resistance than both the substrate and the matrix AA6061 by measuring wear mass loss. Compared with composite samples prepared without laser melting, the wear mass loss of the laser melted composites decreased from 61 to 56 mg under a load of 98 N for 60 min.

  13. In situ epitaxial MgB2 thin films for superconducting electronics.

    Science.gov (United States)

    Zeng, Xianghui; Pogrebnyakov, Alexej V; Kotcharov, Armen; Jones, James E; Xi, X X; Lysczek, Eric M; Redwing, Joan M; Xu, Shengyong; Li, Qi; Lettieri, James; Schlom, Darrell G; Tian, Wei; Pan, Xiaoqing; Liu, Zi-Kui

    2002-09-01

    The newly discovered 39-K superconductor MgB2 holds great promise for superconducting electronics. Like the conventional superconductor Nb, MgB2 is a phonon-mediated superconductor, with a relatively long coherence length. These properties make the prospect of fabricating reproducible uniform Josephson junctions, the fundamental element of superconducting circuits, much more favourable for MgB2 than for high-temperature superconductors. The higher transition temperature and larger energy gap of MgB2 promise higher operating temperatures and potentially higher speeds than Nb-based integrated circuits. However, success in MgB2 Josephson junctions has been limited because of the lack of an adequate thin-film technology. Because a superconducting integrated circuit uses a multilayer of superconducting, insulating and resistive films, an in situ process in which MgB2 is formed directly on the substrate is desirable. Here we show that this can be achieved by hybrid physical-chemical vapour deposition. The epitaxially grown MgB2 films show a high transition temperature and low resistivity, comparable to the best bulk samples, and their surfaces are smooth. This advance removes a major barrier for superconducting electronics using MgB2.

  14. Combustion Synthesis and Densification of NiAl/TiB2 Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A suitable combustion synthesis and densification process was designed to fabricate dense NiAl/TiB2 composites from Ni-Al-Ti-B system. Combustion synthesis processing and microstructure characteristics of products were studied in detail.The results show that the amount of TiB2 ceramics has a great influence on the combustion synthesis processing and microstructure; with the increase of the amount of TiB2 ceramics, the combustion temperature and combustion velocity increase rapidly.The volume of synthesized products and the grain size of ceramics particle size are also affected by the amount of TiB2 ceramics.TiB2 ceramics fiber can be produced in this synthesis system.The dense NiAl/TiB2 composites with residual porosity of no more than 1% are fabricated by the combustion synthesis and hot pressing,the mechanical properties of the dense NiAl/TiB2 composites increase with increase of the amount of TiB2 ceramics.

  15. Ambient temperature cured TiB2 cathode coating for aluminum electrolysis

    Institute of Scientific and Technical Information of China (English)

    赖延清; 李庆余; 杨建红; 李劼

    2003-01-01

    The concept of ambient temperature curable TiB2 cathode coating was put forward, and the ambient temperature curable TiB2 cathode coating was prepared successfully. Differing from the previous TiB2 cathode coating solidified approximately at 200 ℃,the ambient temperature curable TiB2 cathode coating can be solidified at room temperature, so the heating equipment is not necessary, which simplifies the preparation process and facilitates the industrial application of TiB2 cathode coating. Many kinds of resin and curing agent were investigated. On the above-mentioned basis, the ambient temperature curable TiB2 cathode coating was prepared with furan resin 5 500 mixed with complex resins B as carbon binder and DXG1 as curing agent in 24 h. The results show that the properties of prepared coating are excellent, the electrical resistivity is 29.8 μΩ*m, the compressive strength is 33.6 MPa, which are all better than the relevant properties of partially graphitized cathode carbon block for aluminum electrolysis prescribed by the GB 8744-88. SEM morphologies show that the section morphology of the TiB2 coating is unaltered during the electrolysis test, the TiB2 coating can be used in aluminum electrolysis industry to save energy and prolong the life of aluminum electrolysis cell.

  16. 26 CFR 1.6031(b)-2T - REMIC reporting requirements (temporary). [Reserved

    Science.gov (United States)

    2010-04-01

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

  17. Magnetism in the system Ce1-xLaxRh3B2 (abstract)

    Science.gov (United States)

    Malik, S. K.; Umarji, A. M.; Shenoy, G. K.; Aldred, T. A.; Niarchos, D. G.

    1985-04-01

    The RRh3B2 (R=La to Gd) compounds form in the hexagonal CeCo3B2-type structure. The La containing compound in this series has been reported to be a superconductor while CeRh3B2 orders magnetically with Ce being in a nearly 3+ state. The magnetic ordering in CeRh3B2 is presumed to arise from the hybridization of nearly localized 4f electrons of Ce with sp conduction electrons or the 4d band of Rh or from the hybridization of the two. We have examined the magnetic behavior of the system Ce1-xLaxRh3B2 (x=0.0, 0.2, 0.4, 0.6, and 0.8). All these compounds (except LaRh3B2) also order magnetically. The Curie temperature decreases from about 115 K for pure Ce compound to 2.3 K for Ce0.2La0.8Rh3B2. The magnetic moments per formula unit remains nearly constant for 0B2 for x ranging from 0.0 to 0.8. The La-rich side is being investigated for the occurrence of superconductivity. Details will be published elsewhere.

  18. 26 CFR 1.415(b)-2 - Multiple annuity starting dates. [Reserved

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Multiple annuity starting dates. 1.415(b)-2...) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.415(b)-2 Multiple annuity starting dates....

  19. Preparation and characterization of Sc doped MgB2 wires

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Burdusel, M.

    2016-01-01

    The in-situ technique was used to manufacture scandium (Sc) doped MgB2 wires in a composite Cu–Nb sheath. After reaction at 700 °C, at most 1 at.% Mg was replaced by Sc in the MgB2 phase, without significant influence on its superconducting transition temperature. For higher Sc concentrations...

  20. A Decompositional Approach to Executing Quality Data Model Algorithms on the i2b2 Platform

    Science.gov (United States)

    Mo, Huan; Jiang, Guoqian; Pacheco, Jennifer A.; Kiefer, Richard; Rasmussen, Luke V.; Pathak, Jyotishman; Denny, Joshua C.; Thompson, William K.

    2016-01-01

    The Quality Data Model (QDM) is an established standard for representing electronic clinical quality measures on electronic health record (EHR) repositories. The Informatics for Integrated Biology and the Bedside (i2b2) is a widely used platform for implementing clinical data repositories. However, translation from QDM to i2b2 is challenging, since QDM allows for complex queries beyond the capability of single i2b2 messages. We have developed an approach to decompose complex QDM algorithms into workflows of single i2b2 messages, and execute them on the KNIME data analytics platform. Each workflow operation module is composed of parameter lists, a template for the i2b2 message, an mechanism to create parameter updates, and a web service call to i2b2. The communication between workflow modules relies on passing keys ofi2b2 result sets. As a demonstration of validity, we describe the implementation and execution of a type 2 diabetes mellitus phenotype algorithm against an i2b2 data repository. PMID:27570665

  1. 17 CFR 270.24b-2 - Filing copies of sales literature.

    Science.gov (United States)

    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...

  2. Occurrence of Furnonisins B2 and B4 in Retail Raisins

    DEFF Research Database (Denmark)

    Knudsen, Peter Boldsen; Mogensen, Jesper Mølgaard; Larsen, Thomas Ostenfeld;

    2011-01-01

    -MS/MS survey of fumonisins in retail raisins. In 10 of 21 brands collected in Denmark, Germany, and The Netherlands, fumonisins B-2 and B-4 were detected at levels up to 13 and 1.3 mu g/kg, respectively. Only fumonisin B-2 has been detected in wine, so the presence of fumonisin B-4 in raisins suggests...

  3. Antibacterial Peptide CecropinB2 Production via Various Host and Construct Systems

    Directory of Open Access Journals (Sweden)

    Wei-Shiang Lai

    2016-01-01

    Full Text Available Cecropin is a cationic antibacterial peptide composed of 35–39 residues. This peptide has been identified as possessing strong antibacterial activity and low toxicity against eukaryotic cells, and it has been claimed that some types of the cecropin family of peptides are capable of killing cancer cells. In this study, the host effect of cloning antibacterial peptide cecropinB2 was investigated. Three different host expression systems were chosen, i.e., Escherichia coli, Bacillus subtilis and Pichia pastoris. Two gene constructs, cecropinB2 (cecB2 and intein-cecropinB2 (INT-cecB2, were applied. Signal peptide and propeptide from Armigeres subalbatus were also attached to the gene construct. The results showed that the best host for cloning cecropinB2 was P. pastoris SMD1168 harboring the gene of pGAPzαC-prepro-cecB2 via Western blot confirmation. The cecropinB2 that was purified using immobilized-metal affinity chromatography resin showed strong antibacterial activity against the Gram-negative strains, including the multi-drug-resistant bacteria Acinetobacter baumannii.

  4. 新型金属间化合物MgB2超导材料%Novel Intermetallic Compound MgB2 Superconductor

    Institute of Scientific and Technical Information of China (English)

    朱祖昌

    2005-01-01

    2000年10月日本科学家发现了新型金属间化合物MgB2超导体,其超导转变温度Tc为39K,在非铜氧化物块状超导体中最高[1],具有广阔应用前景,MgB2的发现立即使其成为当前超导研究的新热点.本文侧重从材料角度论述MgB2的晶体结构、应用上的优点和主要制造方法.

  5. B2B电子集市重构中国流通经济%Reconstruction of China's Retail Industry through B2B Marketplace

    Institute of Scientific and Technical Information of China (English)

    颜艳春

    2001-01-01

    @@ 自2000年4月美国NASDAQ股市狂跌以来,网络股票一直阴雨绵绵.很多DOTCOM公司 将会长期处于高危险的ILMI运行模式中(投资、烧钱、再投资,Invest,Lose Mo ney,Invest).曾几何时,网络股被炒得发烫.今天,从Boo.com公司的破产,I CP、B2C、B2B公司们的纷纷陨落,到B2C的业界翘楚Amazon.com遭到资本市场的棒 喝,曾经牛气冲天的Tom.com网站不得不裁掉近1/4的员工.真是此一时,彼一时 也.

  6. A New Method for Preparing Superconducting MgB2 Films from Diborane

    Institute of Scientific and Technical Information of China (English)

    王殿生; 傅兴华; 张正平; 杨健

    2002-01-01

    We report on a new preparation method for magnesium diboride (MgB2) films by chemical vapour deposition(CVD) from diborane (B2H6). It is a two-step ex situ approach, with the precursor boron films grown by CVD from B2H6 at 460°C, followed by a post-annealing process in magnesium (Mg) vapour at 830°C. The prepared MgB2 thin films on Al2O3 polycrystalline substrates have an onset transition temperature of 35K and a zeroresistance temperature of about 24K. Well-crystallized MgB2 grains have clearly been observed in the SEM images and confirmed by x-ray diffraction analysis. The advantages of the proposed method are the feasibility to prepare large-area superconducting films and the compatibility with semiconductor technology.

  7. Reactivity of carbides in synthesis of MgB 2 bulks

    Science.gov (United States)

    Yamamoto, Akiyasu; Shimoyama, Jun-ichi; Ueda, Shinya; Horii, Shigeru; Kishio, Kohji

    2006-10-01

    The reactivity of various carbides (B4C, Al4C3, SiC, TiC, ZrC, NbC, Mo2C, HfC and WC) with magnesium and boron in synthesis of MgB2 was systematically studied. Decreases in the a-axis length and transition temperature were observed in all the carbide doped MgB2 bulks, reflecting a certain amount of carbon substituted for boron site in MgB2. The reactivity of each carbide estimated by the carbon content in MgB2 was found to be different depending on the chemical stability. Our results suggest that carbon content in MgB2 lattice can be controlled to its optimal doping level by adjusting synthesis conditions and selection of doping reagents.

  8. Mechanical Properties and Microstructure of In Situ TiB2-7055 Composites

    Institute of Scientific and Technical Information of China (English)

    CHEN dong; LE Yong-kang; BAI Liang; MA Nai-heng; LI Xian-feng; WANG Hao-wei

    2006-01-01

    In order to fabricate a kind of high strength particulate reinforced aluminum-matrix composites, the high strength aluminum alloy 7055 was selected as a matrix. Composites reinforced with varying amounts of TiB2 particles were synthesized using the in situ method, and their mechanical properties and microstructure were analyzed. It is found that the in situ TiB2 particles sized from 50 to 400 nm uniformly disperse in the matrix. With the weight fraction of TiB2 particles increasing, the elastic modulus as well as the yield strength and the ultimate tensile strength increase, while the ductility decrease. The improvement of strength could be attributed to good bonding between TiB2 and the matrix, and also the TiB2 particles act as a barrier to dislocation.

  9. Possible coexistence of superconductivity and magnetic order in NdPt2B2C

    Indian Academy of Sciences (India)

    S K Dhar; A D Chinchure; E Alleno; C Godart; L C Gupta; R Nagarajan

    2002-05-01

    Coexistence of superconductivity and magnetic order has been one of the exciting aspects of the quaternary borocarbide superconductors. So far, RNi2B2C (R=Tm, Er, Ho and Dy) are the only known magnetic superconductors in this family. Here, we present our resistivity, magnetization and heat capacity studies on NdPt2B2C (nominal composition, NdPt1.5Au0.6B2C and NdPt2.1B2.4C1.2). We find superconductivity in both samples with c,onset∼ 3 K. Bulk magnetic order is found to occur below 1.7 K. We suggest that NdPt2B2C is a possible magnetic superconductor.

  10. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2001-04-01

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given.

  11. Reactor Neutrino Spectra

    CERN Document Server

    Hayes, A C

    2016-01-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these and their associated uncertainties are crucial for neutrino oscillation studies. The spectra used to-date have been determined by either conversion of measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that makeup the spectra using modern databases as input. The uncertainties in the subdominant corrections to beta-decay plague both methods, and we provide estimates of these uncertainties. Improving on current knowledge of the antineutrino spectra from reactors will require new experiments. Such experiments would also address the so-called reactor neutrino anomaly and the possible origin of the shoulder observed in the antineutrino spectra measured in recent high-statistics reactor neutrino experiments.

  12. New reactor type proposed

    CERN Multimedia

    2003-01-01

    "Russian scientists at the Research Institute of Nuclear Power Engineering in Moscow are hoping to develop a new reactor that will use lead and bismuth as fuel instead of uranium and plutonium" (1/2 page).

  13. Helias reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Beidler, C.D. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Grieger, G. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Harmeyer, E. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kisslinger, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Karulin, N. [Nuclear Fusion Institute, Moscow (Russian Federation); Maurer, W. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Nuehrenberg, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Rau, F. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Sapper, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Wobig, H. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1995-10-01

    The present status of Helias reactor studies is characterised by the identification and investigation of specific issues which result from the particular properties of this type of stellarator. On the technical side these are issues related to the coil system, while physics studies have concentrated on confinement, alpha-particle behaviour and ignition conditions. The usual assumptions have been made in those fields which are common to all toroidal fusion reactors: blanket and shield, refuelling and exhaust, safety and economic aspects. For blanket and shield sufficient space has been provided, a detailed concept will be developed in future. To date more emphasis has been placed on scoping and parameter studies as opposed to fixing a specific set of parameters and providing a detailed point study. One result of the Helias reactor studies is that physical dimensions are on the same order as those of tokamak reactors. However, it should be noticed that this comparison is difficult in view of the large spectrum of tokamak reactors ranging from a small reactor like Aries, to a large device such as SEAFP. The notion that the large aspect ratio of 10 or more in Helias configurations also leads to large reactors is misleading, since the large major radius of 22 m is compensated by the average plasma radius of 1.8 m and the average coil radius of 5 m. The plasma volume of 1400 m{sup 3} is about the same as the ITER reactor and the magnetic energy of the coil system is about the same or even slightly smaller than envisaged in ITER. (orig.)

  14. Future Reactor Experiments

    OpenAIRE

    He, Miao

    2013-01-01

    The measurement of the neutrino mixing angle $\\theta_{13}$ opens a gateway for the next generation experiments to measure the neutrino mass hierarchy and the leptonic CP-violating phase. Future reactor experiments will focus on mass hierarchy determination and the precision measurement of mixing parameters. Mass hierarchy can be determined from the disappearance of reactor electron antineutrinos based on the interference effect of two separated oscillation modes. Relative and absolute measure...

  15. Reactor Neutrino Experiments

    OpenAIRE

    Cao, Jun

    2007-01-01

    Precisely measuring $\\theta_{13}$ is one of the highest priority in neutrino oscillation study. Reactor experiments can cleanly determine $\\theta_{13}$. Past reactor neutrino experiments are reviewed and status of next precision $\\theta_{13}$ experiments are presented. Daya Bay is designed to measure $\\sin^22\\theta_{13}$ to better than 0.01 and Double Chooz and RENO are designed to measure it to 0.02-0.03. All are heading to full operation in 2010. Recent improvements in neutrino moment measu...

  16. Department of Reactor Technology

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included.......The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included....

  17. Study on the Transport Properties of Superconductor MgB2%MgB2超导体输运特性的研究

    Institute of Scientific and Technical Information of China (English)

    王洪涛; 郑素燕

    2003-01-01

    文中对MgB2超导体的制备过程,对其同位素效应、电阻率、Ⅰ-Ⅴ曲线、热电势、电导涨落效应、能隙、霍尔效应、热重-差热分析实验等输运特性进行了较全面的综述,并讨论了在MgB2超导体基础上的元素替代效应.

  18. Some SEO Skills for Foreign Trade Enterprise' s B2C Website%实用外贸B2C网站SEO优化技巧

    Institute of Scientific and Technical Information of China (English)

    刘庆华

    2012-01-01

    B2C网站是未来外贸企业开展业务的一个方向,而SEO优化是企业B2C网站能否运营成功的基础.列举了一些SEO优化的实用技巧,主要包括:如何选择域名、如何设计网站框架、网站内容如何设计、网站搜索功能如何优化以及如何添加网站的外部链接等.

  19. Moon base reactor system

    Science.gov (United States)

    Chavez, H.; Flores, J.; Nguyen, M.; Carsen, K.

    1989-01-01

    The objective of our reactor design is to supply a lunar-based research facility with 20 MW(e). The fundamental layout of this lunar-based system includes the reactor, power conversion devices, and a radiator. The additional aim of this reactor is a longevity of 12 to 15 years. The reactor is a liquid metal fast breeder that has a breeding ratio very close to 1.0. The geometry of the core is cylindrical. The metallic fuel rods are of beryllium oxide enriched with varying degrees of uranium, with a beryllium core reflector. The liquid metal coolant chosen was natural lithium. After the liquid metal coolant leaves the reactor, it goes directly into the power conversion devices. The power conversion devices are Stirling engines. The heated coolant acts as a hot reservoir to the device. It then enters the radiator to be cooled and reenters the Stirling engine acting as a cold reservoir. The engines' operating fluid is helium, a highly conductive gas. These Stirling engines are hermetically sealed. Although natural lithium produces a lower breeding ratio, it does have a larger temperature range than sodium. It is also corrosive to steel. This is why the container material must be carefully chosen. One option is to use an expensive alloy of cerbium and zirconium. The radiator must be made of a highly conductive material whose melting point temperature is not exceeded in the reactor and whose structural strength can withstand meteor showers.

  20. Corrosion behavior of pristine and added MgB2 in Phosphate Buffered Saline Solution

    Science.gov (United States)

    Batalu, D.; Bojin, D.; Ghiban, B.; Aldica, G.; Badica, P.

    2012-09-01

    We have obtained by Spark Plasma Sintering (SPS), dense samples of MgB2 added with Ho2O3. Starting composition was (MgB2)0.975(HoO1.5)0.025 and we used addition powders with an average particle size below and above 100 nm. For Mg, pristine and added MgB2 samples we measured potentiodynamic polarization curves in Phosphate Buffered Saline (PBS) solution media at room temperature. MgB2 based composites show corrosion/ degradation effects. This behavior is in principle similar to Mg based alloys in the same media. Our work suggests that the different morphologies and phase compositions of the SPS-ed samples influence the interaction with corrosion medium; hence additions can play an important role in controlling the corrosion rate. Pristine MgB2 show a significant improvement of the corrosion resistance, if compared with Mg. The best corrosion resistance is obtained for pristine MgB2, followed by MgB2 with nano-Ho2O3 and μ-Ho2O3 additions.

  1. Low-temperature synthesis of MgB2 via powder metallurgy processing

    Science.gov (United States)

    Birol, Yucel

    2016-12-01

    Ball-milled Mg/B2O3 powder blends reveal interpenetrating layers of deformed magnesium and boron oxide grains that are increasingly refined with increasing milling time. Boron oxide is reduced by Mg and MgO thus formed reacts with the remaining B2O3 to produce Mg3(BO3)2 during ball milling for 30 min. Both B2O3 and Mg3(BO3)2 react with Mg to produce MgB2 upon further ball milling. An annealing treatment can be employed when ball milling is performed for less than 1 h as thermal exposure of the ball-milled Mg/B2O3 powder blends also leads to the formation of MgB2. The above reactions take place between 500 and 700 °C when the Mg/B2O3 powder blend is ball milled for 30 min, and between 450 and 550 °C, after ball milling for 1 h. This is a very attractive route owing to processing temperatures where the volatility of Mg is no longer a problem.

  2. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Consolidation of B4C-TaB2 eutectic composites by spark plasma sintering

    Directory of Open Access Journals (Sweden)

    Dmytro Demirskyi

    2015-12-01

    Full Text Available The in situ synthesis/consolidation of B4C-TaB2 eutectic composites by spark plasma sintering (SPS is reported. The microstructure–property relations were determined for composites with the B4C-TaB2 eutectic composition as functions of TaB2 content, and TaB2-TaB2 interlamellar spacing. A clear maximum in fracture toughness was identified (∼4.5 MPa m1/2 for eutectic composites with interlamellar spacing between 0.9 and 1.1 μm. The composites with the hypereutectic composition of 40 mol.% TaB2 obtained by SPS exhibited lower Vickers hardness (25–26 GPa but higher indentation fracture toughness (up to 4.9 MPa m1/2 than eutectic composites with 30–35 mol.% of TaB2.

  4. Identification of novel nuclear localization signal within the ErbB-2 protein

    Institute of Scientific and Technical Information of China (English)

    Qiao Qiao CHEN; Xiao Ying CHEN; Yun Yun JIANG; Jing LIU

    2005-01-01

    ErbB2,a member of the receptor tyrosine kinase family,is frequently over-expressed in breast cancer.Proteolysis of the extracellular domain of ErbB2 results in constitutive activation of ErbB2 kinase.Recent study reported that ErbB2 is found in the nucleus.Here,we showed that ErbB2 is imported into the nucleus through a nuclear localization signal (NLS)-mediated mechanism.The NLS sequence KRRQQKIRKYTMRR (aa655-668) contains three clusters of basic amino acids and it is sufficient to target GFP into the nucleus.However,mutation in any basic amino acid cluster of this NLS sequence significantly affects its nuclear localization.Furthermore,it was found that this NLS is essential for the nuclear localization of ErbB2 since the intracellular domain of Erb2 lacking NLS completely abrogates its nuclear translocation.Taken together,our study identified a novel nuclear localization signal and reveals a novel mechanism underlying ErbB2 nuclear trafficking and localization.

  5. Herschel observations of the Sgr B2 cores: Hydrides, warm CO, and cold dust

    CERN Document Server

    Etxaluze, M; Cernicharo, J; Polehampton, E T; Noriega-Crespo, A; Molinari, S; Swinyard, B M; Wu, R; Bally, J

    2013-01-01

    Sagittarius B2 (Sgr B2) is one of the most massive and luminous star-forming regions in the Galaxy and shows chemical and physical conditions similar to those in distant extragalactic starbursts. We present large-scale far-IR/submm photometric images and spectroscopic maps taken with the PACS and SPIRE instruments onboard Herschel. The spectra towards the Sgr B2 star-forming cores, B2(M) and B2(N), are characterized by strong CO line emission, emission lines from high-density tracers (HCN, HCO+, and H2S), [N II] 205 um emission from ionized gas, and absorption lines from hydride molecules (OH+, H2O+, H2O, CH+, CH, SH+, HF, NH, NH2, and NH3). The rotational population diagrams of CO suggest the presence of two gas temperature components: an extended warm component, which is associated with the extended envelope, and a hotter component, which is seen towards the B2(M) and B2(N) cores. As observed in other Galactic Center clouds, the gas temperatures are significantly higher than the dust temperatures inferred f...

  6. EXPRESSION AND SIGNIFICANCE OF C-erbB-2 IN THE TISSUES OF LUNG CANCER

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To elucidate the expression and clinical significance of C-erbB-2 in the tissue of lung cancer. Methods Immunohistochemistry method was used to detect the protein expression of C-erbB-2 in lung cancer tissue. Results The positive expression rate of C-erbB-2 protein in 38 cases of lung cancer was 53.3% (21/38),which was higher than those in lung benign control group (P<0. 001). The significant correlation were found between the protein level and tumor stage(r= +0. 64,P<0.02). The order was stage Ⅳ>stage Ⅲ >stage Ⅱ >stage Ⅰ . There was no correlation among protein expression of C-erbB-2 in various histological types of lung cancer (P>0.05 for all). Conclusion The positive expression rates of C-erbB-2 were significantly higher in lung cancer group than those in benign control group. There is significant correlation between C-erbB-2 expression and lung cancer stage. There is no correlation among protein expression of C-erbB-2 and histological types of lung cancer.

  7. 关于B2B服务品牌忠诚度的研究%Research On The B2B Service Brand Loyalty

    Institute of Scientific and Technical Information of China (English)

    孔令明; 耿禧则

    2012-01-01

    对于品牌忠诚度的研究,过去一直局限于产品品牌上。将品牌忠诚度理论运用于B2B服务品牌,通过实证调查,研究品牌认知度与品牌形象对态度忠诚度和行动忠诚度的影响作用,并据此为B2B服务品牌的成功管理提出若干可行性方案。%For brand loyalty of research, the past has been confined to the product brand. This paper brand loyalty theory is applied to B2B service brand. Through the empirical research, the effect of the brand recognition and brand image to action loyalty and attitude loyalty, And put forward some feasible solutions of the B2B service brand management .

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

    DEFF Research Database (Denmark)

    Toft, Katrine Nørgaard

    along [110], the magnetic structure rotates a small angle of 0.5 degrees away from the symmetrydirection. TmNi2B2C: A magnetic field applied in the [100] direction suppresses the zero field magnetic structure QF = (0.094,0.094,0) (TN = 1.6 K), in favor of the Fermi surface nesting structure QN = (0......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...... 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...

  9. Superconducting Properties and Microstructure in MgB2 Bulks, Wires and Tapes

    Institute of Scientific and Technical Information of China (English)

    冯勇; 阎果; 赵勇; 吴晓京; 周廉; 张平祥

    2003-01-01

    We prepared a series of MgB2 bulk samples under different temperatures, holding time and increasing rates in temperature by the solid state reaction. The thermodynamic behavior and phase formation in the Mg-B system were studied by using DTA,XRD and SEM. The results indicate that the formation of the MgB2 phase is very fast and the high increasing rate in temperature is necessary to obtain high quality MgB2. In addition, the effects of the Zr-doping in Mg1-xZrxB2 bulk samples fabricated by the solid state reaction at ambient pressure on phase compositions, microstructure and flux pinning behavior were investigated by using XRD, SQUID magnetometer, SEM and TEM. Critical current density Jc can be significantly enhanced by the Zr-doping and the best data are achieved in Mg0.9Zr0.1B2. For this sample, Jc values are remarkably improved to 1.83×106 A/cm2 in self-field and 5.51×105 A/cm2 in 1 T at 20 K. Also, high quality MgB2/Ta/Cu wires and tapes with and without Ti-doping, MgB2/Fe wires and 18 filament MgB2/NbZr/Cu tapes were fabricated by the powder-in-tube (PIT) method at ambient pressure. The phase compositions, microstructure features and flux pinning properties were studied. The results suggest that Fe is thebest metal for these sheaths. MgB2/Fe wires exhibit very high Jc at high temperatures and high fields. Jc values reach as high as 1.43×105 A/cm2 (4.2 K, 4 T) and 3.72×104 A/cm2 (15 K, 4 T).

  10. Nociceptor-expressed ephrin-B2 regulates inflammatory and neuropathic pain

    Directory of Open Access Journals (Sweden)

    Kullander Klas

    2010-11-01

    Full Text Available Abstract Background EphB receptors and their ephrin-B ligands play an important role in nervous system development, as well as synapse formation and plasticity in the adult brain. Recent studies show that intrathecal treatment with EphB-receptor activator ephrinB2-Fc induced thermal hyperalgesia and mechanical allodynia in rat, indicating that ephrin-B2 in small dorsal root ganglia (DRG neurons and EphB receptors in the spinal cord modulate pain processing. To examine the role of ephrin-B2 in peripheral pain pathways, we deleted ephrin-B2 in Nav1.8+ nociceptive sensory neurons with the Cre-loxP system. Sensory neuron numbers and terminals were examined using neuronal makers. Pain behavior in acute, inflammatory and neuropathic pain models was assessed in the ephrin-B2 conditional knockout (CKO mice. We also investigated the c-Fos expression and NMDA receptor NR2B phosphorylation in ephrin-B2 CKO mice and littermate controls. Results The ephrin-B2 CKO mice were healthy with no sensory neuron loss. However, pain-related behavior was substantially altered. Although acute pain behavior and motor co-ordination were normal, inflammatory pain was attenuated in ephrin-B2 mutant mice. Complete Freund's adjuvant (CFA-induced mechanical hyperalgesia was halved. Formalin-induced pain behavior was attenuated in the second phase, and this correlated with diminished tyrosine phosphorylation of N-methyl-D-aspartic acid (NMDA receptor subunit NR2B in the dorsal horn. Thermal hyperalgesia and mechanical allodynia were significantly reduced in the Seltzer model of neuropathic pain. Conclusions Presynaptic ephrin-B2 expression thus plays an important role in regulating inflammatory pain through the regulation of synaptic plasticity in the dorsal horn and is also involved in the pathogenesis of some types of neuropathic pain.

  11. Molecular cloning and characterization of SoxB2 gene from Zhikong scallop Chlamys farreri

    Science.gov (United States)

    He, Yan; Bao, Zhenmin; Guo, Huihui; Zhang, Yueyue; Zhang, Lingling; Wang, Shi; Hu, Jingjie; Hu, Xiaoli

    2013-11-01

    The Sox proteins play critical roles during the development of animals, including sex determination and central nervous system development. In this study, the SoxB2 gene was cloned from a mollusk, the Zhikong scallop ( Chlamys farreri), and characterized with respect to phylogeny and tissue distribution. The full-length cDNA and genomic DNA sequences of C. farreri SoxB2 ( Cf SoxB2) were obtained by rapid amplification of cDNA ends and genome walking, respectively, using a partial cDNA fragment from the highly conserved DNA-binding domain, i.e., the High Mobility Group (HMG) box. The full-length cDNA sequence of Cf SoxB2 was 2 048 bp and encoded 268 amino acids protein. The genomic sequence was 5 551 bp in length with only one exon. Several conserved elements, such as the TATA-box, GC-box, CAAT-box, GATA-box, and Sox/sry-sex/testis-determining and related HMG box factors, were found in the promoter region. Furthermore, real-time quantitative reverse transcription PCR assays were carried out to assess the mRNA expression of Cf SoxB 2 in different tissues. SoxB2 was highly expressed in the mantle, moderately in the digestive gland and gill, and weakly expressed in the gonad, kidney and adductor muscle. In male and female gonads at different developmental stages of reproduction, the expression levels of Cf SoxB2 were similar. Considering the specific expression and roles of SoxB 2 in other animals, in particular vertebrates, and the fact that there are many pallial nerves in the mantle, cerebral ganglia in the digestive gland and gill nerves in gill, we propose a possible essential role in nervous tissue function for Sox B 2 in C. farreri.

  12. Depletion of the xynB2 gene upregulates β-xylosidase expression in C. crescentus.

    Science.gov (United States)

    Corrêa, Juliana Moço; Mingori, Moara Rodrigues; Gandra, Rinaldo Ferreira; Loth, Eduardo Alexandre; Seixas, Flávio Augusto Vicente; Simão, Rita de Cássia Garcia

    2014-01-01

    Caulobacter crescentus is able to express several enzymes involved in the utilization of lignocellulosic biomasses. Five genes, xynB1-5, that encode β-xylosidases are present in the genome of this bacterium. In this study, the xynB2 gene, which encodes β-xylosidase II (CCNA_02442), was cloned under the control of the PxylX promoter to generate the O-xynB2 strain, which overexpresses the enzyme in the presence of xylose. In addition, a null mutant strain, Δ-xynB2, was created by two homologous recombination events where the chromosomal xynB2 gene was replaced by a copy that was disrupted by the spectinomycin-resistant cassette. We demonstrated that C. crescentus cells lacking β-xylosidase II upregulates the xynB genes inducing β-xylosidase activity. Transcriptional analysis revealed that xynB1 (RT-PCR analysis) and xynB2 (lacZ transcription fusion) gene expression was induced in the Δ-xynB2 cells, and high β-xylosidase activity was observed in the presence of different agro-industrial residues in the null mutant strain, a characteristic that can be explored and applied in biotechnological processes. In contrast, overexpression of the xynB2 gene caused downregulation of the expression and activity of the β-xylosidase. For example, the β-xylosidase activity that was obtained in the presence of sugarcane bagasse was 7-fold and 16-fold higher than the activity measured in the C. crescentus parental and O-xynB2 cells, respectively. Our results suggest that β-xylosidase II may have a role in controlling the expression of the xynB1 and xynB2 genes in C. crescentus.

  13. Reactor Safety Planning for Prometheus Project, for Naval Reactors Information

    Energy Technology Data Exchange (ETDEWEB)

    P. Delmolino

    2005-05-06

    The purpose of this letter is to submit to Naval Reactors the initial plan for the Prometheus project Reactor Safety work. The Prometheus project is currently developing plans for cold physics experiments and reactor prototype tests. These tests and facilities may require safety analysis and siting support. In addition to the ground facilities, the flight reactor units will require unique analyses to evaluate the risk to the public from normal operations and credible accident conditions. This letter outlines major safety documents that will be submitted with estimated deliverable dates. Included in this planning is the reactor servicing documentation and shipping analysis that will be submitted to Naval Reactors.

  14. REACTOR GROUT THERMAL PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.

    2011-01-28

    Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

  15. Dendrite crystal morphology evolution mechanism of β-BaB2O4 crystal

    Institute of Scientific and Technical Information of China (English)

    HE ChongJun; ZHONG WeiZhuo; LIU YouWen

    2009-01-01

    Existence of [B3-O6]3- hexagonal ring growth unit in melt solution of β-BaB2O4 crystal was proved by the results of high temperature Raman measurements. A morphology evolution process of β-BaB2O4 crys-tal was observed by a high temperature in-situ observation device. The crystal morphology varied with the supersaturation of growth melt solution. The mechanism of β-BaB2O4 crystal morphology evolution was analyzed through the growth unit model.

  16. Dendrite crystal morphology evolution mechanism of β-BaB2O4 crystal

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Existence of [B3-O6]3- hexagonal ring growth unit in melt solution of β-BaB2O4 crystal was proved by the results of high temperature Raman measurements.A morphology evolution process of β-BaB2O4 crys-tal was observed by a high temperature in-situ observation device.The crystal morphology varied with the supersaturation of growth melt solution.The mechanism of β-BaB2O4 crystal morphology evolution was analyzed through the growth unit model.

  17. Improving magnetic properties of MgB2 bulk superconductors by synthetic engine oil treatment

    Science.gov (United States)

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

    2016-08-01

    The present study focuses on the effects of standby time of the MgB2 samples immersed in synthetic engine oil on the critical current density (Jc(H)), magnetic field dependence of the pinning force density fp(b) and Tc performances of MgB2 bulk superconductors. Synthetic engine oil was used as a product which is cheap and a rich carbon source. Manufactured MgB2 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, MgB2 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 MgB2 samples immersed at different standby time in engine oil in whole field range was better than that of the pure MgB2 sample because of the number of the pinning centers. The MgB2 sample immersed at 300 min standby time in synthetic engine oil has the best performance compared to other samples. The Jc value for the pure sample is 2.0 × 103 A/cm2, whereas for the MgB2 sample immersed at 300 min standby time in engine oil the Jc is enhanced to 4.8 × 103A/cm2 at 5 K and 3 T. The superconducting transition temperature (Tc) did not change with the increasing standby time of the samples in synthetic engine oil at all. The best diamagnetic property was obtained from the sample which kept in synthetic engine oil for 300 min. Synthetic engine oil treatment results in remarkable improvement of the critical current density and pinning force performances of MgB2 superconductors. It was found that all MgB2 samples have a different pinning property at different measuring temperatures. Using synthetic engine oil as a product which is cheap and a rich carbon source in MgB2 bulk superconductors makes MgB2 samples immersed in synthetic engine oil a good candidate for industrial applications.

  18. Improved critical current density of MgB2--carbon nanotubes composite.

    Science.gov (United States)

    Shekhar, Chandra; Giri, Rajiv; Malik, S K; Srivastav, O N

    2007-06-01

    In the present study, we report a systematic study of doping/admixing of carbon nanotubes (CNTs) in different concentrations in MgB2. The composite material corresponding to MgB2-x at.% CNTs (35 at.% > or = x > or = 0 at.%) have been prepared by solid-state reaction at ambient pressure. All the samples in the present investigation have been subjected to structural/microstructural characterization employing XRD, Scanning electron microscopic (SEM), and Transmission electron microscopic (TEM) techniques. The magnetization measurements were performed by Physical property measurement system (PPMS) and electrical transport measurements have been done by the four-probe technique. The microstructural investigations reveal the formation of MgB2-carbon nanotube composites. A CNT connecting the MgB2 grains may enhance critical current density due to its size (approximately 5-20 nm diameter) compatible with coherence length of MgB2 (approximately 5-6 nm) and ballistic transport current carrying capability along the tube axis. The transport critical current density (Jct) of MgB2 samples with varying CNTs concentration have been found to vary significantly e.g., Jct of the MgB2 sample with 10 at.% CNT addition is approximately 2.3 x 10(3) A/cm2 and its value for MgB2 sample without CNT addition is approximately 7.2 x 102 A/cm2 at 20 K. In order to study the flux pinning effect of CNTs doping/ admixing in MgB2, the evaluation of intragrain critical current density (JJ) has been carried out through magnetic measurements on the fine powdered version of the as synthesized samples. The optimum result on Jc is obtained for 10 at.% CNTs admixed MgB2 sample at 5 K, the Jc reaches approximately 5.2 x 10(6) A/cm2 in self field, -1.6 x 10(6) A/cm2 at 1 T, approximately 2.9 x 10(5) A/cm2 at 2.6 T, and approximately 3.9 x 10(4) A/cm2 at 4 T. The high value of intragrain Jc in 10 at.% CNTs admixed MgB2 superconductor has been attributed to the incorporation of CNTs into the crystal matrix of

  19. FASN, ErbB2-mediated glycolysis is required for breast cancer cell migration.

    Science.gov (United States)

    Zhou, Lan; Jiang, Sufang; Fu, Qiang; Smith, Kelly; Tu, Kailing; Li, Hua; Zhao, Yuhua

    2016-05-01

    Both fatty acid synthase (FASN) and ErbB2 have been shown to promote breast cancer cell migration. However, the underlying molecular mechanism remains poorly understood and there is no reported evidence that directly links glycolysis to breast cancer cell migration. In this study, we investigated the role of FASN, ErbB2-mediated glycolysis in breast cancer cell migration. First, we compared lactate dehydrogenase A (LDHA) protein levels, glycolysis and cell migration between FASN, ErbB2-overexpressing SK-BR-3 cells and FASN, ErbB2-low-expressing MCF7 cells. Then, SK-BR-3 cells were treated with cerulenin (Cer), an inhibitor of FASN, and ErbB2, LDHA protein levels, glycolysis, and cell migration were detected. Next, we transiently transfected ErbB2 plasmid into MCF7 cells and detected FASN, LDHA protein levels, glycolysis and cell migration. Heregulin-β1 (HRG-β1) is an activator of ErbB2 and 2-deoxyglucose (2-DG) and oxamate (OX) are inhibitors of glycolysis. MCF7 cells were treated with HRG-β1 alone, HRG-β1 plus 2-DG, OX or cerulenin and glycolysis, and cell migration were measured. We found that FASN, ErbB2-high-expressing SK-BR-3 cells displayed higher levels of glycolysis and migration than FASN, ErbB2-low-expressing MCF7 cells. Inhibition of FASN by cerulenin impaired glycolysis and migration in SK-BR-3 cells. Transient overexpression of ErbB2 in MCF7 cells promotes glycolysis and migration. Moreover, 2-deoxyglucose (2-DG), oxamate (OX), or cerulenin partially reverses heregulin-β1 (HRG-β1)-induced glycolysis and migration in MCF7 cells. In conclusion, this study demonstrates that FASN, ErbB2-mediated glycolysis is required for breast cancer cell migration. These novel findings indicate that targeting FASN, ErbB2-mediated glycolysis may be a new approach to reverse breast cancer cell migration.

  20. Hg Substitution Effect on Superconductivity and Crystal Structure of MgB2

    Institute of Scientific and Technical Information of China (English)

    Ya-Jing Cui; Yong-Liang Chen; Ye Yang; Yong Zhang; Cui-Hua Cheng; Yong Zhao

    2008-01-01

    Polycrystalline Mg1-xHgxB2 samples with x=0, 1%, 2.5%, 5%, 7.5%, and 10% have been synthe- sized by solid-state reaction. Different from the substitu- tion effect of Al, C, Li, etc. on crystal structure of MgB2, Hg substitution for Mg results in an increase of the lattice constant in both a and c directions. The super- conductivity of MgB2 is also suppressed by Hg substi- tution. The observed suppression of super- conductivity by Hg substitution is discussed in terms of the interband impurity scattering effect in two-band superconductors.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  2. Glass formation and crystallization of high lead content PbO-B2O3 compositions

    Science.gov (United States)

    Weinberg, Michael C.; Smith, Gary L.; Neilson, George F.

    1986-01-01

    The glass-forming and undercooling ability of PbO-B2O3 melts in the 2PbO.B2O3 to 4PbO.B2O3 composition range were studied. The glass formation propensities were investigated as a function of cooling rate and sample mass. A qualitative investigation of the crystallization process(es) preventing glass formation was made, and it was concluded that under normal circumstances heterogeneous nucleation was the common occurrence. Hence, it was concluded that such compositions are prime candidates for containerless experiments aboard the Space Shuttle.

  3. erbB-2 autophosphorylation is required for mitogenic action and high-affinity substrate coupling

    DEFF Research Database (Denmark)

    Segatto, O; Lonardo, F; Helin, K;

    1992-01-01

    -mutated chimera. When expressed in NR6 cells, the EGFR/erbB-2 5P mutant was unable to deliver a sizeable mitogenic signal when activated by EGF at physiological levels. In intact cells, the 5P mutant was still able to stimulate phosphorylation of the gamma isozyme of phospholipase C (PLC-gamma), a prototype erb......B-2 substrate, although with a delayed time course, indicating that the 5P mutation decreased the affinity of the erbB-2 kinase for this substrate. This conclusion was further supported by the inability of the 5P mutant to associate with PLC-gamma in co-immunoprecipitation experiments. We infer...

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

    OpenAIRE

    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...

  5. A New Method for the Preparation of MgB2 Superconducting Tapes

    Institute of Scientific and Technical Information of China (English)

    许加迪; 王淑芳; 周岳亮; 戴守愚; 陈正豪; 崔大复; 吕惠宾; 朱亚斌; 何萌; 杨国桢

    2002-01-01

    Superconducting MgB2/Ta tapes with a critical temperature of 38 K have been prepared successfully by a two-step method. Boron/Ta tapes were fabricated by electrophoresis followed by a post-annealing process in magnesium vapour. The critical current density is 1.7 × 104 A/cm2 in zero field at 5K. Scanning electron microscopy and x-ray diffraction analysis reveal a dense flat surface with (101) orientated growth of the MgB2 phase in our MgB2/Ta tapes.

  6. An Empirical Examination of Reverse Auction Appropriateness in B2B Source Selection

    Science.gov (United States)

    2006-01-01

    Measures of Marketing Constructs," Journal of Marketing Research, Vol. 16, No.2, pp. 64 - 73. Cohn, L. (2000), " B2B : The Hottest Net Bet Yet...AND SUBTITLE 5. FUNDING NUMBERS AN EMPIRICAL EXAMINATION OF REVERSE AUCTION APPROPRIATENESS IN B2B SOURCE SELECTION. 6. AUTHOR(S) MAJ HAWKINS TIMOTHY...Examination of Reverse Auction Appropriateness in B2B Source Selection D :7;TZU IUT•ITM STATER,;77TIT A Approved for Puhtic P-•-!,ase Distribution

  7. The Importance of Brand on B2B Markets: Case Study of Hilti

    OpenAIRE

    Konečný, Martin

    2012-01-01

    The brand is mostly associated with business-to-customer markets and environment. People would first think of such a brand, because we see marketing and advertising of those brands every day. But business-to-business brands are for companies also very important. The overall goal of my thesis would be to find out how the managers of a pure B2B company perceive the importance of brand in the B2B environment where the company operates. Theoretical part will, in the first chapter, characterize B2...

  8. German Special Operations in the 1944 Ardennes Offensive

    Science.gov (United States)

    1994-06-03

    through the maze of traffic jams and poor roads, Skorzeny could not assemble them for an attack on the 19th, and accordingly the operation was...requesting care for his men.9 0 Von der Heydte traveled east on the 21st with his executive officer and runner towards Monschau, wlhich he a.bwned was In

  9. Scaleable, High Efficiency Microchannel Sabatier Reactor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Microchannel Sabatier Reactor System (MSRS) consisting of cross connected arrays of isothermal or graded temperature reactors is proposed. The reactor array...

  10. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Takeshi; Iida, Masaaki; Moriki, Yasuyuki

    1994-10-18

    A reactor core is divided into a plurality of coolants flowrate regions, and electromagnetic pumps exclusively used for each of the flowrate regions are disposed to distribute coolants flowrates in the reactor core. Further, the flowrate of each of the electromagnetic pumps is automatically controlled depending on signals from a temperature detector disposed at the exit of the reactor core, so that the flowrate of the region can be controlled optimally depending on the burning of reactor core fuels. Then, the electromagnetic pumps disposed for every divided region are controlled respectively, so that the coolants flowrate distribution suitable to each of the regions can be attained. Margin for fuel design is decreased, fuels are used effectively, as well as an operation efficiency can be improved. Moreover, since the electromagnetic pump has less flow resistance compared with a mechanical type pump, and flow resistance of the reactor core flowrate control mechanism is eliminated, greater circulating flowrate can be ensured after occurrence of accident in a natural convection using a buoyancy of coolants utilizable for after-heat removal as a driving force. (N.H.).

  11. Reactor Structural Materials: Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R

    2000-07-01

    The objectives of SCK-CEN's R and D programme on Rector Pressure Vessel (RPV) Steels are:(1) to complete the fracture toughness data bank of various reactor pressure vessel steels by using precracked Charpy specimens that were tested statically as well as dynamically; (2) to implement the enhanced surveillance approach in a user-friendly software; (3) to improve the existing reconstitution technology by reducing the input energy (short cycle welding) and modifying the stud geometry. Progress and achievements in 1999 are reported.

  12. Electronic structure of MgB2 from angle-resolved photoemission spectroscopy.

    Science.gov (United States)

    Uchiyama, H; Shen, K M; Lee, S; Damascelli, A; Lu, D H; Feng, D L; Shen, Z-X; Tajima, S

    2002-04-15

    The first angle-resolved photoemission spectroscopy results from MgB2 single crystals are reported. Along the GammaK and GammaM directions, we observed three distinct dispersive features approaching the Fermi energy. These can be assigned to the theoretically predicted sigma (B 2p(x,y)) and pi (B 2p(z)) bands. In addition, a small parabolic-like band is detected around the Gamma point, which can be attributed to a surface-derived state. The overall agreement between our results and the band calculations suggests that the electronic structure of MgB2 is of a conventional nature, thus implying that electron correlations are weak and may be of little importance to superconductivity in this system.

  13. Coherent phonon decay and the boron isotope effect for MgB2.

    Science.gov (United States)

    Alarco, Jose A; Talbot, Peter C; Mackinnon, Ian D R

    2014-12-14

    Ab initio DFT calculations for the phonon dispersion (PD) and the phonon density of states (PDOS) of the two isotopic forms ((10)B and (11)B) of MgB2 demonstrate that use of a reduced symmetry super-lattice provides an improved approximation to the dynamical, phonon-distorted P6/mmm crystal structure. Construction of phonon frequency plots using calculated values for these isotopic forms gives linear trends with integer multiples of a base frequency that change in slope in a manner consistent with the isotope effect (IE). Spectral parameters inferred from this method are similar to that determined experimentally for the pure isotopic forms of MgB2. Comparison with AlB2 demonstrates that a coherent phonon decay down to acoustic modes is not possible for this metal. Coherent acoustic phonon decay may be an important contributor to superconductivity for MgB2.

  14. Epitaxial growth of MgB2 films at ambient temperature

    Science.gov (United States)

    Shishido, Hiroaki; Yoshida, Takuya; Nakagami, Takatoshi; Ishida, Takekazu

    We grew crystalline MgB2 thin films using molecular beam epitaxy at a low substrate temperature of 110 °C under an ultrahigh vacuum of about 10-6 Pa. MgB2 thin films were deposited on the (001) surface of a 4H-SiC substrate with an epitaxial Mg buffer layer. The epitaxial growth was confirmed by X-ray diffraction measurements. MgB2 thin films show a sharp superconducting transition at 27.2 K, with a relatively narrow superconducting transition width ΔTc = 0.9 K. The growth temperature was lower than any in prior reports on superconducting MgB2 thin films. The presence of the epitaxial Mg buffer layer is crucial for reducing the epitaxial temperature.

  15. Observation and Properties of L=1 B_1 and B_2* Mesons

    CERN Document Server

    Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, C; Clement, B; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, G; De, K; De Jong, S J; de Jong, P; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutíerrez, P; Gutíerrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A I; Kharzheev, Yu M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kühl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G L; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajícek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perea, P M; Peters, K; Peters, Y; Petroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Polozov, P; Pompo, A; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S D; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F K; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A F S; Savage, G; Sawyer, L; Scanlon, T; Schaile, A D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schliephake, T; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sen-Gupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Simák, V; Sirotenko, V I; Skubic, P L; Slattery, P F; Smirnov, D; Smith, R P; Snow, J; Snow, G R; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Strauss, E; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Tanasijczuk, A; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, S; Uvarov, L; Uzunyan, S; Vachon, B; Van den Berg, P J; van Eijk, B; Van Kooten, R; Van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A H; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Séguier, F; Vint, P; Vokac, P; Von Törne, E; Voutilainen, M; Vreeswijk, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L; Warchol, J; Watts, G; Wayne, M; Weber, M; Weber, G; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Williams, M R J; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, J; Yu, C; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G

    2007-01-01

    Excited B mesons B_1 and B_2* are observed directly for the first time as two separate states in fully reconstructed decays to B+(*) pi-. The mass of B_1 is measured to be (5720.6 +- 2.4 +- 1.4) MeV/c^2 and the mass difference DeltaM between B_2* and B_1 is (26.2 +- 3.1 +- 0.9) MeV/c^2, giving the mass of the B_2* as (5746.8 +- 2.4 +- 1.7) MeV/c^2. The production rate for B_1 and B_2* mesons is determined to be a fraction (13.9 +- 1.9 +- 3.2)% of the production rate of the B+ meson.

  16. Rapid determination of vitamin B2 and B12 in human urine by isocratic liquid chromatography.

    Science.gov (United States)

    Mandal, Santi M; Mandal, Mahitosh; Ghosh, Ananta K; Dey, Satyahari

    2009-04-27

    A simple and rapid method for the identification and quantification of vitamin B(2) and B(12) in human urine has been developed using reverse phase high performance liquid chromatography (HPLC) and the peaks identity were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). HPLC separation was performed in single wavelength detector (lambda(365)) mode and separated isocratically using mobile phase methanol: 1mM aqueous TFA (1:4) in C18 column. The calibration graphs plotted with different concentrations of vitamin B(2) and B(12) was linear with a correlation coefficients (r(2))=0.9975 and 0.9985, respectively. The recoveries of vitamin B(2) and B(12) were above 87% and 90%, respectively. The results of this present study suggest that the proposed method may be simple and convenient way of identifying and quantifying vitamin B(2) and B(12) from human urine.

  17. Data of evolutionary structure change: 1AW2B-2VENA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1AW2B-2VENA 1AW2 2VEN B A --RHPVVMGNWKLNGSKEMVVDLLNGLNAELEGVTGVDV...RQLDAVINTQGVEALEGAIIAYEPIWAIGTGKAATAEDAQRIHAQIRAHIAEK-SEAVAKNVVIQYGGSVKPENAAAYFAQPDIDGALVGGAALDAKSFAAIAKAAAE...ine> 2VEN A 2VENA1 2VEN A 2VENA... A 2VENA YEPVW-----KVATP

  18. Superior homogeneity of trapped magnetic field in superconducting MgB2 bulk magnets

    Science.gov (United States)

    Ishihara, A.; Akasaka, T.; Tomita, M.; Kishio, K.

    2017-03-01

    Homogeneity of trapped magnetic field in radial and circumferential directions of high temperature superconducting bulk magnets, MgB2 (T c ˜38.3 K) and YBa2Cu3O y (T c ˜91.5 K), have been measured. In polycrystalline MgB2 bulks, the circularity of trapped magnetic field in a cylindrical disk is over 97% at 20-32.5 K, while that of YBa2Cu3O y was ˜87% at 77 K. Magnetic field distribution of MgB2 bulk was satisfactorily homogeneous and these measurements suggest MgB2 bulks with highly efficient cryocoolers should be very useful for novel high field permanent magnet applications.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Anisotropy oxidation of textured ZrB2–MoSi2 ceramics

    DEFF Research Database (Denmark)

    Liu, Hai-Tao; Zou, Ji; Ni, De Wei

    2012-01-01

    Oxidation behavior of hot forged textured ZrB2–20vol% MoSi2 ceramics with platelet ZrB2 grains was investigated at 1500°C for exposure time from 0.5 to 12h. Compared to untextured ceramics, the textured ceramics showed obvious anisotropic oxidation behavior and the surface normal to the hot forging...... pressure demonstrated better oxidation resistance. Such improvement in the oxidation resistance is primarily considered as a higher intrinsic ZrB2 atomic density on the orientated {00l} planes in the textured ceramics. It is expectable that the anisotropic textured ZrB2–MoSi2 ceramics can offer better...

  1. Intestinal colonization with phylogenetic group B2 Escherichia coli related to inflammatory bowel disease

    DEFF Research Database (Denmark)

    Petersen, Andreas Munk; Halkjær, Sofie Ingdam; Gluud, Lise Lotte

    2015-01-01

    BACKGROUND AND OBJECTIVES: Increased numbers of Escherichia coli and, furthermore, specific subtypes of E. coli, such as E. coli of the phylogenetic groups B2 and D have been found in the intestine of patients with inflammatory bowel disease (IBD). In this review, we wanted to evaluate...... on 163 patients with IBD and 89 controls. Among IBD patients, 57 patients had ulcerative colitis (UC) and 95 Crohn's disease (CD). Random-effects meta-analysis showed that IBD patients were more likely to have B2 E. coli intestinal colonization compared with controls (odds ratio [OR]: 2.28; 95...... to be related to IBD, UC or CD. CONCLUSIONS: Our study reveals that intestinal colonization with phylogenetic group B2 E. coli is associated with UC. Due to the design, we are unable to determine if the colonization with B2 E. coli leads to the development of the disease or the disease increases the risk...

  2. Ferromagnetic enhancement in the hexagonal Ce(Rh1-xIrx)3B2 system

    Science.gov (United States)

    Hsu, S. W.; Ku, H. C.

    1988-08-01

    Electrical resistivity, magnetization, and crystallographic measurements have been carried out for the pseudoternary system Ce(Rh1-xIrx)3B2. A single-phase hexagonal CeCo3B2-type structure persists from x=0.0 up to x0.95. The ferromagnetic Curie temperature Tc is enhanced from 115 K for CeRh3B2 to 125 K for Ce(Rh0.8Ir0.2)32, then decreases slowly to 118 K at x=0.5 before decreasing sharply to 69 K at x=0.67, even though the magnetic moment per Ce ion decreases monotonically with increasing Ir substitution. The Tc of 125 K in Ce(Rh0.8Ir0.2)3B2 is the highest magnetic-ordering temperature observed so far for all Ce-based systems with nonmagnetic constituents.

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

    DEFF Research Database (Denmark)

    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 model...... innovation. However, social media application is hindered due to lack of specific local knowledge, lack of knowledge on social media technicalities and bewilderedness on leadership approaches within the social media application. A contribution is hereby made to the B2B SME field, to the academic...... understanding an insight on social media application and open business model innovation....

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

    Energy Technology Data Exchange (ETDEWEB)

    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. (LSP)

  5. Proton Mobility in b2 Ion Formation and Fragmentation Reactions of Histidine-Containing Peptides

    Science.gov (United States)

    Nelson, Carissa R.; Abutokaikah, Maha T.; Harrison, Alex G.; Bythell, Benjamin J.

    2016-03-01

    A detailed energy-resolved study of the fragmentation reactions of protonated histidine-containing peptides and their b2 ions has been undertaken. Density functional theory calculations were utilized to predict how the fragmentation reactions occur so that we might discern why the mass spectra demonstrated particular energy dependencies. We compare our results to the current literature and to synthetic b2 ion standards. We show that the position of the His residue does affect the identity of the subsequent b2 ion (diketopiperazine versus oxazolone versus lactam) and that energy-resolved CID can distinguish these isomeric products based on their fragmentation energetics. The histidine side chain facilitates every major transformation except trans-cis isomerization of the first amide bond, a necessary prerequisite to diketopiperazine b2 ion formation. Despite this lack of catalyzation, trans-cis isomerization is predicted to be facile. Concomitantly, the subsequent amide bond cleavage reaction is rate-limiting.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Dehybridization of the 4f shell in Si-substituted CeRh3B2

    Science.gov (United States)

    Malik, S. K.; Shenoy, G. K.; Dhar, S. K.; Paulose, P. L.; Vijayaraghavan, R.

    1986-12-01

    The compound CeRh3B2 is known to order magnetically with an unusually high Curie temperature (TC) of 115 K and a low saturation moment of about 0.4μB. We have studied the magnetic behavior of the system CeRh3(B1-xSix)2 (0CeRh3B2 arises because of the Ce 4f hybridization with the neighboring ligands.

  8. Study of magnetic behaviour of CeRh3B2 using111Cd probe

    Science.gov (United States)

    Nyayate, M. N.; Devare, S. H.; Devare, H. G.

    1989-06-01

    Using111Cd probe nuclei, the transferred H hf( T) is measured down to 35 K in CeRh3B2 using TDPAC technique. The angle β between the EFG and the direction of magnetization is obtained to be 90°. The observed small H hf( T) may be a consequence of the reduced moment on Ce in CeRh3B2.

  9. High Upper Critical Field and Irreversibility Field in MgB2 Coated-Conductor Fibers

    Science.gov (United States)

    2016-06-13

    conductor fibers deposited by hybrid physical- chemical vapor deposition on SiC fibers. The coating is polycrystalline and composed of elongated...High upper critical field and irreversibility field in MgB2 coated -conductor fibers V. Ferrando,a P. Orgiani,b A. V. Pogrebnyakov, J. Chen, Qi Li...2005; accepted 14 November 2005; published online 14 December 2005 We report on structural and superconducting properties of round MgB2 coated

  10. Drivers of relationships affecting B2B firms in an e-commerce environment

    Directory of Open Access Journals (Sweden)

    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.

  11. Framing agenda for business model innovation research from the B2B context

    OpenAIRE

    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.

  12. An ANFIS-based on B2C electronic commerce transaction

    Energy Technology Data Exchange (ETDEWEB)

    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

    Science.gov (United States)

    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. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1994-08-01

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their (thermionic reactor) performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling.

  15. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly

    2013-01-01

    The development of a nuclear rocket engine reactor (NRER ) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  16. Operation of Reactor

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    3.1 Annual Report of SPR Operation Chu Shaochu Having overseen by National Nuclear Safety Administration and specialists, the reactor restarted up successfully after Safety renovation on April 16, 1996. In August 1996 the normal operation of SPR was approved by the authorities of Naitonal Nuclear Safety Administration. 1 Operation status In 1996, the reactor operated safely for 40 d and the energy released was about 137.3 MW·d. The operation status of SPR is shown in table 1. The reactor started up to higher power (power more than 1 MW) and lower power (for physics experiments) 4 times and 14 times respectively. Measurement of control rod efficiency and other measurement tasks were 2 times and 5 times respectively.

  17. An Overview of Reactor Concepts, a Survey of Reactor Designs.

    Science.gov (United States)

    1985-02-01

    Public Affairs Office and is releasaole to the National Technical Information Services (NTIS). At NTIS, it will be available to the general public...Reactors that use deu- terium (heavy water) as a coolant can use natural uranium as a fuel. The * Canadian reactor, CANDU , utilizes this concept...reactor core at the top and discharged at the Dotton while the reactor is in operation. The discharged fuel can then b inspected to see if it can De used

  18. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.

    2014-01-01

    Full Text Available Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles, providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles. This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

  19. High critical currents in iron-clad superconducting MgB2 wires.

    Science.gov (United States)

    Jin, S; Mavoori, H; Bower, C; van Dover, R B

    2001-05-31

    Technically useful bulk superconductors must have high transport critical current densities, Jc, at operating temperatures. They also require a normal metal cladding to provide parallel electrical conduction, thermal stabilization, and mechanical protection of the generally brittle superconductor cores. The recent discovery of superconductivity at 39 K in magnesium diboride (MgB2) presents a new possibility for significant bulk applications, but many critical issues relevant for practical wires remain unresolved. In particular, MgB2 is mechanically hard and brittle and therefore not amenable to drawing into the desired fine-wire geometry. Even the synthesis of moderately dense, bulk MgB2 attaining 39 K superconductivity is a challenge because of the volatility and reactivity of magnesium. Here we report the successful fabrication of dense, metal-clad superconducting MgB2 wires, and demonstrate a transport Jc in excess of 85,000 A cm-2 at 4.2 K. Our iron-clad fabrication technique takes place at ambient pressure, yet produces dense MgB2 with little loss of stoichiometry. While searching for a suitable cladding material, we found that other materials dramatically reduced the critical current, showing that although MgB2 itself does not show the 'weak-link' effect characteristic of the high-Tc superconductors, contamination does result in weak-link-like behaviour.

  20. Quantum confinement induced band gaps in MgB2 nanosheets

    Science.gov (United States)

    Xu, Bo Z.; Beckman, Scott P.

    2016-09-01

    The discovery of two-dimensional semiconducting materials, a decade ago, spawned an entire sub-field within solid-state physics that is focused on the development of nanoelectronics. Here we present a new class of semiconducting two-dimensional material based on hexagonal MgB2. Although MgB2 is a semimetal, similar to the other well-studied transition metal diborides, we demonstrate that, unlike the transition metal diborides, thinning MgB2, to create nanosheets, opens a band gap in the density of states. We predict that a 7 Å thick MgB2 nanosheet will have a band gap of 0.51 eV. MgB2 nanosheets differ from other two-dimensional semiconductors in that the band gap is introduced by (001) surfaces and is opened by the quantum confinement effect. The implications of these findings are that nanostructured MgB2 is not merely a new composition, but also has intrinsic mechanisms for tuning its electronic properties, which may facilitate the development of nanoelectronics.

  1. Crystal Structures, Stabilities, Electronic Properties, and Hardness of MoB2: First-Principles Calculations.

    Science.gov (United States)

    Ding, Li-Ping; Shao, Peng; Zhang, Fang-Hui; Lu, Cheng; Ding, Lei; Ning, Shu Ya; Huang, Xiao Fen

    2016-07-18

    On the basis of the first-principles techniques, we perform the structure prediction for MoB2. Accordingly, a new ground-state crystal structure WB2 (P63/mmc, 2 fu/cell) is uncovered. The experimental synthesized rhombohedral R3̅m and hexagonal AlB2, as well as theoretical predicted RuB2 structures, are no longer the most favorite structures. By analyzing the elastic constants, formation enthalpies, and phonon dispersion, we find that the WB2 phase is thermodynamically and mechanically stable. The high bulk modulus B, shear modulus G, low Poisson's ratio ν, and small B/G ratio are benefit to its low compressibility. When the pressure is 10 GPa, a phase transition is observed between the WB2-MoB2 and the rhombohedral R3̅m MoB2 phases. By analyzing the density of states and electron density, we find that the strong covalent is formed in MoB2 compounds, which contributes a great deal to its low compressibility. Furthermore, the low compressibility is also correlated with the local buckled structure.

  2. Erythropoietin promotes bone formation through EphrinB2/EphB4 signaling.

    Science.gov (United States)

    Li, C; Shi, C; Kim, J; Chen, Y; Ni, S; Jiang, L; Zheng, C; Li, D; Hou, J; Taichman, R S; Sun, H

    2015-03-01

    Recent studies have demonstrated that erythropoietin (EPO) has extensive nonhematopoietic biological functions. However, little is known about how EPO regulates bone formation, although several studies suggested that EPO can affect bone homeostasis. In this study, we investigated the effects of EPO on the communication between osteoclasts and osteoblasts through the ephrinB2/EphB4 signaling pathway. We found that EPO slightly promotes osteoblastic differentiation with the increased expression of EphB4 in ST2 cells. However, EPO increased the expression of Nfatc1 and ephrinB2 but decreased the expression of Mmp9 in RAW264.7 cells, resulting in an increase of ephrinB2-expressing osteoclasts and a decrease in resorption activity. The stimulation of ephrinB2/EphB4 signaling via ephrinB2-Fc significantly promoted EPO-mediated osteoblastic differentiation in ST2 cells. EphB4 knockdown through EphB4 shRNA inhibited EPO-mediated osteoblastic phenotypes. Furthermore, in vivo assays clearly demonstrated that EPO efficiently induces new bone formation in the alveolar bone regeneration model. Taken together, these results suggest that ephrinB2/EphB4 signaling may play an important role in EPO-mediated bone formation.

  3. Degradation of aromatic compounds and degradative pathway of 4-nitrocatechol by Ochrobactrum sp. B2.

    Science.gov (United States)

    Zhong, Qiuzan; Zhang, Haiyan; Bai, Wenqin; Li, Mei; Li, Baotong; Qiu, Xinghui

    2007-12-01

    The potential capacity of a soil methyl parathion-degrading bacterium strain, Ochrobactrum sp. B2, for degrading various aromatic compounds were investigated. The results showed B2 was capable of degrading diverse aromatic compounds, but amino-substituted benzene compounds, at a concentration up to 100 mg L(-1) in 4 days. B2 could use 4-nitrocatechol (4-NC) as a sole carbon and energy source with release of nitrite ion. The pathway for 4-NC degradation via 1,2,4-benzenetriol (BT) and hydroquinone (HQ) formation in B2 was proposed based on the identification and quantification of intermediates by gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatography (HPLC). Degradation studies carried out on a plasmid-cured derivative showed that the genes for 4-NC degradative pathway was plasmid-borne in B2, suggesting that B2 degrades both p-nitrophenol and 4-NC by enzymes encoded by genes on the same plasmid.

  4. Investigation of lauric acid dopant as a novel carbon source in MgB 2 wire

    Science.gov (United States)

    Lee, C. M.; Lee, S. M.; Park, G. C.; Joo, J.; Lim, J. H.; Kang, W. N.; Yi, J. H.; Jun, B.-H.; Kim, C.-J.

    2010-11-01

    We fabricated lauric acid (LA) doped MgB2 wires and investigated the effects of the LA doping. For the fabrication of the LA-doped MgB2 wires, B powder was mixed with LA at 0-5 wt.% of the total amount of MgB2 using an organic solvent, dried, and then the LA-treated B and Mg powders were mixed stoichiometrically. The powder mixture was loaded into an Fe tube and the assemblage was drawn and sintered at 900 °C for 3 h under an argon atmosphere. We observed that the LA doping induced the substitution of C for the B sites in MgB2 and that the actual content of C increased monotonically with increasing LA doping level. The LA-doped MgB2 wires exhibited a lower critical temperature (Tc), but better critical current density (Jc) behavior in a high magnetic field: the 5 wt.% LA-doped sample had a Jc value of 5.32 × 103 A/cm2, which was 2.17 times higher than that of the pristine sample (2.45 × 103 A/cm2) at 5 K and 6 T, suggesting that LA is an effective C dopant in MgB2 for enhancing the high-field Jc performance.

  5. Alginate/chitosan nanoparticles for encapsulation and controlled release of vitamin B2.

    Science.gov (United States)

    Azevedo, Maria A; Bourbon, Ana I; Vicente, António A; Cerqueira, Miguel A

    2014-11-01

    This work aims at evaluating encapsulation and controlled release of vitamin B2 from alginate/chitosan nanoparticles. Ionotropic polyelectrolyte pre-gelation was used as production method being chitosan and alginate used as main materials. Nanoparticles were characterized in terms of average size, polydispersity index (PDI), zeta potential and vitamin entrapment efficiency. The average size for alginate/chitosan nanoparticles was 119.5±49.9nm for samples without vitamin B2 and 104.0±67.2nm with the encapsulation of vitamin B2, presenting a PDI of 0.454±0.066 and 0.319±0.068, respectively. The nanoparticles showed encapsulation efficiency and loading capacity values of 55.9±5.6% and 2.2±0.6%, respectively. Release profiles were evaluated at different conditions showing that the polymeric relaxation was the most influent phenomenon in vitamin B2 release. In order to study their stability nanoparticles were stored at 4°C being particles sizes and PDI evaluated during 5 months showing the results that vitamin B2-loaded nanoparticles are more stable (in terms of size and PDI) than nanoparticles without vitamin B2.

  6. Two novel human anti-ErbB2 immunoagents are active on trastuzumab-resistant tumours

    Science.gov (United States)

    Gelardi, T; Damiano, V; Rosa, R; Bianco, R; Cozzolino, R; Tortora, G; Laccetti, P; D'Alessio, G; De Lorenzo, C

    2010-01-01

    Background: Overexpression of ErbB2 receptor in breast cancer is associated with disease progression and poor prognosis. Trastuzumab, the only humanised anti-ErbB2 antibody currently used in breast cancer, has proven to be effective; however, a relevant problem for clinical practice is that a high fraction of breast cancer patients shows primary or acquired resistance to trastuzumab treatment. Methods: We tested on trastuzumab-resistant cells two novel human anti-tumour immunoconjugates engineered in our laboratory by fusion of a human anti-ErbB2 scFv, termed Erbicin, with either a human RNase or the Fc region of a human IgG1. Both Erbicin-derived immunoagents (EDIAs) are selectively cytotoxic for ErbB2-positive cancer cells in vitro and vivo, target an ErbB2 epitope different from that recognised by trastuzumab and do not show cardiotoxic effects. Results: We report that EDIAs are active also on trastuzumab-resistant tumour cells both in vitro and in vivo, most likely because of the different epitope recognised, as EDIAs, unlike trastuzumab, were found to be able to inhibit the signalling pathway downstream of ErbB2. Conclusion: These results suggest that EDIAs are immunoagents that could not only fulfil the therapeutic need of patients ineligible to trastuzumab treatment due to cardiac dysfunction but also prove to be useful for breast cancer patients unresponsive to trastuzumab treatment. PMID:20051960

  7. Magnetic and NMR investigation of RRh3B2 (R=La to Gd) compounds

    Science.gov (United States)

    Malik, S. K.; Dhar, S. K.; Vijayaraghavan, R.; Wallace, W. E.

    1982-11-01

    Magnetization (4.2 to 300 K) and 11B paramagnetic NMR (77 to 300 K) studies have been carried out on ternary borides RRh3B2 (R=La to Gd). These compounds crystallize in the CeCo3B2-type structure. From cell volume considerations Ce is in a mixed valent/quadrivalent state while the rest of the rare earth ions are in a trivalent state. With the exception of La and Pr compounds, all other compounds are found to order magnetically. From the high values of the ratio of paramagnetic moment to ordered state moment, the magnetic ordering is inferred to be the itinerant type in CeRh3B2 and EuRh3B2. In Nd and Gd compounds, magnetization data reveal that magnetic ordering is associated with the rare earth sublattice. A complex behavior of magnetization is observed in SmRh3B2. A first order quadrupole split 11B NMR spectrum is observed in Ce, Pr, Nd, and Sm compounds. The boron Knight shift in all these compounds is small and, within the limits of experimental error, scales linearly with susceptibility in Pr and Nd compounds. A temperature independent Knight shift is observed in SmRh3B2, indicating the influence of strong crystal fields.

  8. Role of kinin B2 receptors in opioid-induced hyperalgesia in inflammatory pain in mice.

    Science.gov (United States)

    Grastilleur, Sébastien; Mouledous, Lionel; Bedel, Jerome; Etcheverry, Jonathan; Bader, Michael; Girolami, Jean-Pierre; Fourcade, Olivier; Frances, Bernard; Minville, Vincent

    2013-03-01

    Postoperative pain management is a clinical challenge that can be complicated by opioid-induced hyperalgesia (OIH). Kinin receptors could mediate both the acute and chronic phases of inflammation and pain. A few recent studies suggest that dynorphin A could maintain neuropathic pain by activating the bradykinin (BK) receptor. Thus, the effect of a single administration of sufentanil (a μ-opioid receptor agonist) was investigated in a model of carrageenan-induced inflammatory pain using three strains of mice, i.e., knockout mice for one kinin receptor, B1R or B2R (B1KO, B2KO), and wild-type C57/BL6J mice (WT) treated with either a B1R (R954) or a B2R antagonist (HOE140) or a KKS inhibitor (aprotinin). Pain was assessed and compared between the different groups using two behavioral tests exploring mechanical (von Frey filaments) and thermal (Hargreaves test) sensitivity. Pretreatment with sufentanil induced a sustained increase in pain sensitivity with a delayed return to baseline values characterizing an OIH in carrageenan-injected mice only. Sufentanil-induced OIH was not observed in B2KO but persisted in B1KO and was blunted by aprotinin and the B2R antagonist only. Collectively, our data indicate that the B2R receptor and BK synthesis or availability are essential peripheral steps in the mechanism leading to OIH in a pain context.

  9. Wettability and Reactivity of ZrB2 Substrates with Liquid Al

    Science.gov (United States)

    Nowak, R.; Sobczak, N.; Bruzda, G.; Wojewoda-Budka, J.; Litynska-Dobrzynska, L.; Homa, M.; Kaban, I.; Xi, L.; Jaworska, L.

    2016-08-01

    Wetting characteristics of the Al/ZrB2 system were experimentally determined by the sessile drop method with application of separate heating of the ZrB2 and Al samples and combined with in situ cleaning of Al drop from native oxide film directly in vacuum chamber. The tests were performed in ultrahigh vacuum of 10-6 mbar at temperatures 710, 800, and 900 °C as well as in flowing inert gas (Ar) atmosphere at 1400 °C. The results evidenced that liquid Al does not wet ZrB2 substrate at 710 and 800 °C, forming high contact angles ( θ) of 128° and 120°, respectively. At 900 °C, wetting phenomenon ( θ contact angle decreases monotonically to the final value of 80°. At 1400 °C, wetting takes place immediately after drop deposition with a fast decrease in the contact angle to 76°. The solidified Al/ZrB2 couples were studied by scanning and transmission electron microscopy coupled with x-ray energy diffraction spectroscopy. Structural characterization revealed that only in the Al/ZrB2 couple produced at the highest temperature of 1400 °C new phases (Al3Zr, AlB2 and α-Al2O3) were formed.

  10. Chimeric DNA Vaccines against ErbB2{sup +} Carcinomas: From Mice to Humans

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. The Process of TiB2-Cu Composite Phase and Structure Formation during Combustion Synthesis

    Institute of Scientific and Technical Information of China (English)

    XU Qiang; ZHANG Xinghong; HAN Jiecai; PAN Wei

    2006-01-01

    The reaction process of combustion synthesis for TiB2- Cu was investigated in detail using combustion-wave arresting experiment, X-ray diffraction (XRD) analysis, SEM analysis and differential thermal analysis ( DTA ). The XRD analysis results for the different parts of the quenched specimen shaw that TiCux intermetallic phase firstly forms with the propagation of combustion wave, and then Ti1.87 B50 and Ti3 B4 metastable phases come forth due to the diffusion of B atoms and finally the stable TiB2 phase forms because of the continuous diffusion of B atoms. The formation of TiB2 phase is not completed by one step, but undergoes several transient processes. The process of reaction synthesis for Ti-B-Cu ternary system can be divided into three main stages: melting of Cu and Ti, and the formation of Cu- Ti melt and few TiCux , TiBx intermetallic phases; large numbers of TiCux intermetallic phases formation and some fine TiB2 particles precipitation; and the TiB2 particles coarsening and the stable TiB2 and Cu two phases formation in the final product.

  12. Mechanical and tribological characterization of TiB2 thin films.

    Science.gov (United States)

    Silva, F J G; Casais, R C B; Martinho, R P; Baptista, A P M

    2012-12-01

    Titanium Diboride (TiB2) presents high mechanical and physical properties. Some wear studies were also carried out in order to evaluate its tribological properties. One of the most popular wear tests for thin films is the ball-cratering configuration. This work was focused on the study of the tribological properties of TiB2 thin films using micro-abrasion tests and following the BS EN 1071-6: 2007 standard. Due to high hardness usually patented by these films, diamond was selected as abrasive on micro-abrasion tests. Micro-abrasion wear tests were performed under five different durations, using the same normal load, speed rotation and ball. Films were deposited by unbalanced magnetron sputtering Physical Vapour Deposition (PVD) technique using TiB2 targets. TiB2 films were characterized using different methods as Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), Electron Probe Micro-Analyser (EPMA), Ultra Micro Hardness and Scratch-test Analysis, allowing to confirm that TiB2 presents adequate mechanical and physical properties. Ratio between hardness (coating and abrasive particles), wear resistance and wear coefficient were studied, showing that TiB2 films shows excellent properties for tribological applications.

  13. Fabrication and superconducting properties of nano-SiC doped MgB2 tapes

    Institute of Scientific and Technical Information of China (English)

    ZHANG XianPing; MA YanWei; GAO ZhaoShun; YU ZhengGuang; WANG DongLiang; WATANABE K; GUO JianDong

    2007-01-01

    Nano-SiC doped MgB2 tapes were prepared by the in situ powder-in-tube method. Heat treatment was performed at 650℃ for 1 h. XRD data indicate that SiC particles had reacted with the MgB2 during sintering process. MgB2 core seemed to be denser after SiC doping, and the critical temperature was slightly depressed. The critical current density Jc of the SiC doped tapes was significantly enhanced in magnetic fields up to 14 T compared to the undoped ones. For the 5% SiC doped samples, Jc was increased by a factor of 32 at 4.2 K, 10 T. The enhancement of Jc-B properties in SiC doped MgB2 tapes is considered to be due to the enhancement of grain linkages and the introduction of effective flux pining centers. The substitution of B by C in MgB2 grains is thought to be the main reason for the improvement of the flux pinning ability in SiC doped MgB2 tapes.

  14. Flotillins as regulators of ErbB2 levels in breast cancer

    DEFF Research Database (Denmark)

    Pust, S; Klokk, T I; Musa, N;

    2013-01-01

    Amplification and overexpression of the receptor tyrosine kinase ErbB2 occur in up to 30% of human breast cancers, and high ErbB2 levels are correlated with poor prognosis for breast cancer patients. In contrast to the epithelial growth factor receptor (ErbB1), ErbB2 is not downregulated by ligand...... from 194 patients diagnosed with carcinomas of the breast showed that flotillin-2 emerged as a potential predictor of prognosis in breast cancer. Depletion of flotillin-1 and flotillin-2 leads to internalization and degradation of ErbB2. Furthermore, flotillin-1 and -2 were found to be in a molecular......-induced mechanisms. Here we show that flotillins are involved in the stabilization of ErbB2 at the plasma membrane. In SKBR3 breast cancer cells and breast cancer tissue, a positive correlation between flotillin and ErbB2 expression levels could be demonstrated. Moreover, the tissue microarray analyses of biopsies...

  15. Regulation of ErbB2 localization and function in breast cancer cells by ERM proteins

    Science.gov (United States)

    Asp, Nagham; Kvalvaag, Audun; Sandvig, Kirsten; Pust, Sascha

    2016-01-01

    The ERM protein family is implicated in processes such as signal transduction, protein trafficking, cell proliferation and migration. Consequently, dysregulation of ERM proteins has been described to correlate with carcinogenesis of different cancer types. However, the underlying mechanisms are poorly understood. Here, we demonstrate a novel functional interaction between ERM proteins and the ErbB2 receptor tyrosine kinase in breast cancer cells. We show that the ERM proteins ezrin and radixin are associated with ErbB2 receptors at the plasma membrane, and depletion or functional inhibition of ERM proteins destabilizes the interaction of ErbB2 with ErbB3, Hsp90 and Ebp50. Accompanied by the dissociation of this protein complex, binding of ErbB2 to the ubiquitin-ligase c-Cbl is increased, and ErbB2 becomes dephosphorylated, ubiquitinated and internalized. Furthermore, signaling via Akt- and Erk-mediated pathways is impaired upon ERM inhibition. Finally, interference with ERM functionality leads to receptor degradation and reduced cellular levels of ErbB2 and ErbB3 receptors in breast cancer cells. PMID:27029001

  16. Congenital hyperreninemic hypoaldosteronism unlinked to the aldosterone synthase (CYP11B2) gene.

    Science.gov (United States)

    Kayes-Wandover, K M; Tannin, G M; Shulman, D; Peled, D; Jones, K L; Karaviti, L; White, P C

    2001-11-01

    Isolated hyperreninemic hypoaldosteronism presenting in infancy is usually caused by mutations in the CYP11B2 gene encoding aldosterone synthase. We studied five patients in four unrelated kindreds with hyperreninemic hypoaldosteronism, in whom we were unable to find such mutations. All presented in infancy with failure to thrive, hyponatremia, hyperkalemia, markedly elevated plasma renin activity, and low or inappropriately normal aldosterone levels. All had normal cortisol levels and no signs or symptoms of congenital adrenal hyperplasia. All responded to fludrocortisone treatment. There were no mutations detected in exons or splice junctions of CYP11B2. Linkage of the disorder to CYP11B2 was studied in two unrelated consanguineous patients and in an affected sib pair. The consanguineous patients were each heterozygous for at least one of three polymorphic microsatellite markers near CYP11B2, excluding linkage to CYP11B2. However, linkage of the disease to CYP11B2 could not be excluded in the affected sib pair. Genes involved in the regulation of aldosterone biosynthesis, including those encoding angiotensinogen, angiotensin-converting enzyme, and the AT1 angiotensin II receptor were similarly excluded from linkage. These results demonstrate the existence of an inherited form of hyperreninemic hypoaldosteronism distinct from aldosterone synthase deficiency. The affected gene(s) remain to be determined.

  17. Preferential control of basal dendritic protrusions by EphB2.

    Directory of Open Access Journals (Sweden)

    Matthew S Kayser

    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.

  18. Perspectives on reactor safety

    Energy Technology Data Exchange (ETDEWEB)

    Haskin, F.E. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Camp, A.L. [Sandia National Labs., Albuquerque, NM (United States)

    1994-03-01

    The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course.

  19. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2002-04-01

    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel.

  20. LINGO-1 regulates oligodendrocyte differentiation by inhibiting ErbB2 translocation and activation in lipid rafts.

    Science.gov (United States)

    Lee, Xinhua; Shao, Zhaohui; Sheng, Guoqing; Pepinsky, Blake; Mi, Sha

    2014-05-01

    Oligodendrocyte differentiation is negatively regulated by LINGO-1 and positively regulated by the ErbB2 receptor tyrosine kinase. In wild-type oligodendrocytes, inhibition of ErbB2 blocks differentiation, whereas activation of ErbB2 promotes differentiation. In LINGO-1(-/-) oligodendrocytes, inhibition of ErbB2 blocks oligodendrocyte differentiation; whereas activation of ErbB2 does not enhance differentiation. Biological and biochemical evidence showing that LINGO-1 can directly bind to ErbB2, block ErbB2 translocation into lipid rafts, and inhibit its phosphorylation for activation. The study demonstrates a novel regulatory mechanism of ErbB2 function whereby LINGO-1 suppresses oligodendrocyte differentiation by inhibiting ErbB2 translocation and activation in lipid rafts.

  1. Ab initio Computations of the Electronic, Mechanical, and Thermal Properties of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2

    Science.gov (United States)

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

    2011-01-01

    Refractory materials such as metallic borides, often considered as ultra high temperature ceramics (UHTC), are characterized by high melting point, high hardness, and good chemical inertness. These materials have many applications which require high temperature materials that can operate with no or limited oxidation. Ab initio, first principles methods are the most accurate modeling approaches available and represent a parameter free description of the material based on the quantum mechanical equations. Using these methods, many of the intrinsic properties of these material can be obtained. We performed ab initio calculations based on density functional theory for the UHTC materials ZrB2 and HfB2. Computational results are presented for structural information (lattice constants, bond lengths, etc), electronic structure (bonding motifs, densities of states, band structure, etc), thermal quantities (phonon spectra, phonon densities of states, specific heat), as well as information about point defects such as vacancy and antisite formation energies.

  2. Study on Internet - consumer Satisfaction Under B2C Pattern%B2C模式下网络消费者满意的研究

    Institute of Scientific and Technical Information of China (English)

    刘宏; 黄小刚; 刘振涛; 乔彦东

    2004-01-01

    结合我国B2C模式的电子商务中消费群体现状,分析了网络消费群体的消费心理和消费行为特征,研究了影响网络消费者满意度的因素,并提出了针对网络消费者满意度的测评模型和指标体系.

  3. Mechanical properties of ZrB2- and HfB2-based ultra-high temperature ceramics fabricated by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Solvas, E. [Imperial College, London; Jayaseelan, D. [Imperial College, London; Lin, Hua-Tay [ORNL; Brown, P. [DSTL, Porton Down, Salisbury, Wiltshire, UK; Lee, W.E. [Imperial College, London

    2013-01-01

    Flexural strengths at room temperature, at 1400 C in air and at room temperature after 1 h oxidation at 1400 C were determined for ZrB2- and HfB2-based ultra-high temperature ceramics (UHTCs). Defects caused by electrical discharge machining (EDM) lowered measured strengths significantly and were used to calculate fracture toughness via a fracture mechanics approach. ZrB2 with 20 vol.% SiC had room temperature strength of 700 90 MPa, fracture toughness of 6.4 0.6 MPa, Vickers hardness at 9.8 N load of 21.1 0.6 GPa, 1400 C strength of 400 30 MPa and room temperature strength after 1 h oxidation at 1400 C of 678 15 MPa with an oxide layer thickness of 45 5 m. HfB2 with 20 vol.% SiC showed room temperature strength of 620 50 MPa, fracture toughness of 5.0 0.4 MPa, Vickers hardness at 9.8 N load of 27.0 0.6 GPa, 1400 C strength of 590 150 MPa and room temperature strength after 1 h oxidation at 1400 C of 660 25 MPa with an oxide layer thickness of 12 1 m. 2 wt.% La2O3 addition to UHTCs slightly reduced mechanical performance while increasing tolerance to property degradation after oxidation and effectively aided internal stress relaxation during spark plasma sintering (SPS) cooling, as quantified by X-ray diffraction (XRD). Slow crack growth was suggested as the failure mechanism at high temperatures as a consequence of sharp cracks formation during oxidation.

  4. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Haselow, J.S.; Price, V.; Stephenson, D.E.; Bledsoe, H.W.; Looney, B.B.

    1989-12-01

    The Savannah River Site (SRS) produces nuclear materials, primarily plutonium and tritium, to meet the requirements of the Department of Defense. These products have been formed in nuclear reactors that were built during 1950--1955 at the SRS. K, L, and P reactors are three of five reactors that have been used in the past to produce the nuclear materials. All three of these reactors discontinued operation in 1988. Currently, intense efforts are being extended to prepare these three reactors for restart in a manner that protects human health and the environment. To document that restarting the reactors will have minimal impacts to human health and the environment, a three-volume Reactor Operations Environmental Impact Document has been prepared. The document focuses on the impacts of restarting the K, L, and P reactors on both the SRS and surrounding areas. This volume discusses the geology, seismology, and subsurface hydrology. 195 refs., 101 figs., 16 tabs.

  5. High Flux Isotope Reactor (HFIR)

    Data.gov (United States)

    Federal Laboratory Consortium — The HFIR at Oak Ridge National Laboratory is a light-water cooled and moderated reactor that is the United States’ highest flux reactor-based neutron source. HFIR...

  6. Competency-orientated brand cooperations of power supply companies in the B2B sector; Kompetenzorientierte Markenkooperationen von Energieversorgungsunternehmen im B2B-Kundenbereich

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Reactor operation safety information document

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The report contains a reactor facility description which includes K, P, and L reactor sites, structures, operating systems, engineered safety systems, support systems, and process and effluent monitoring systems; an accident analysis section which includes cooling system anomalies, radioactive materials releases, and anticipated transients without scram; a summary of onsite doses from design basis accidents; severe accident analysis (reactor core disruption); a description of operating contractor organization and emergency planning; and a summary of reactor safety evolution. (MB)

  8. e-Relationships for e-Readiness:culture and corruption in international e-B2B

    OpenAIRE

    Berthon, Pierre; Pitt, Leyland; Berthon, Jean-Paul; Campbell, Colin; Thwaites, Des

    2008-01-01

    The role of electronic networks in B2B relationships has been growing exponentially. From massive internet B2B exchanges to tiny RFID chips, B2B is increasingly becoming e-B2B. Whilst e-B2B has been explored intra-nationally, its international counterpart is less well documented; as has been the role that culture might play in the development of international e-B2B relationships. In this paper we address this important issue of international e-business relationships. Specifically we explore t...

  9. Thermal Reactor Safety

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

  10. Chromatographic and Related Reactors.

    Science.gov (United States)

    1988-01-07

    special information about effects of surface heteroge- neity in the methanation reaction. Studies of an efficient multicolumn assembly for measuring...of organic basic catalysts such as pyridine and 4-methylpicoline. It was demonstrated that the chromatographic reactor gave special information about...Programmed Reaction to obtain special information about surface heterogeneity in the methanation reaction. Advantages of stopped flow over steady state

  11. Nuclear Reactors and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. [eds.

    1992-01-01

    This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

  12. Fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  13. WATER BOILER REACTOR

    Science.gov (United States)

    King, L.D.P.

    1960-11-22

    As its name implies, this reactor utilizes an aqueous solution of a fissionable element salt, and is also conventional in that it contains a heat exchanger cooling coil immersed in the fuel. Its novelty lies in the utilization of a cylindrical reactor vessel to provide a critical region having a large and constant interface with a supernatant vapor region, and the use of a hollow sleeve coolant member suspended from the cover assembly in coaxial relation with the reactor vessel. Cool water is circulated inside this hollow coolant member, and a gap between its outer wall and the reactor vessel is used to carry off radiolytic gases for recombination in an external catalyst chamber. The central passage of the coolant member defines a reflux condenser passage into which the externally recombined gases are returned and condensed. The large and constant interface between fuel solution and vapor region prevents the formation of large bubbles and minimizes the amount of fuel salt carried off by water vapor, thus making possible higher flux densities, specific powers and power densities.

  14. The First Reactor.

    Science.gov (United States)

    Department of Energy, Washington, DC.

    On December 2, 1942, in a racquet court underneath the West Stands of Stagg Field at the University of Chicago, a team of scientists led by Enrico Fermi created the first controlled, self-sustaining nuclear chain reaction. This updated and revised story of the first reactor (or "pile") is based on postwar interviews (as told to Corbin…

  15. MULTISTAGE FLUIDIZED BED REACTOR

    Science.gov (United States)

    Jonke, A.A.; Graae, J.E.A.; Levitz, N.M.

    1959-11-01

    A multistage fluidized bed reactor is described in which each of a number of stages is arranged with respect to an associated baffle so that a fluidizing gas flows upward and a granular solid downward through the stages and baffles, whereas the granular solid stopsflowing downward when the flow of fluidizing gas is shut off.

  16. ErbB2-dependent chemotaxis requires microtubule capture and stabilization coordinated by distinct signaling pathways.

    Directory of Open Access Journals (Sweden)

    Khedidja Benseddik

    Full Text Available Activation of the ErbB2 receptor tyrosine kinase stimulates breast cancer cell migration. Cell migration is a complex process that requires the synchronized reorganization of numerous subcellular structures including cell-to-matrix adhesions, the actin cytoskeleton and microtubules. How the multiple signaling pathways triggered by ErbB2 coordinate, in time and space, the various processes involved in cell motility, is poorly defined. We investigated the mechanism whereby ErbB2 controls microtubules and chemotaxis. We report that activation of ErbB2 increased both cell velocity and directed migration. Impairment of the Cdc42 and RhoA GTPases, but not of Rac1, prevented the chemotactic response. RhoA is a key component of the Memo/ACF7 pathway whereby ErbB2 controls microtubule capture at the leading edge. Upon Memo or ACF7 depletion, microtubules failed to reach the leading edge and cells lost their ability to follow the chemotactic gradient. Constitutive ACF7 targeting to the membrane in Memo-depleted cells reestablished directed migration. ErbB2-mediated activation of phospholipase C gamma (PLCγ also contributed to cell guidance. We further showed that PLCγ signaling, via classical protein kinases C, and Memo signaling converged towards a single pathway controlling the microtubule capture complex. Finally, inhibiting the PI3K/Akt pathway did not affect microtubule capture, but disturbed microtubule stability, which also resulted in defective chemotaxis. PI3K/Akt-dependent stabilization of microtubules involved repression of GSK3 activity on the one hand and inhibition of the microtubule destabilizing protein, Stathmin, on the other hand. Thus, ErbB2 triggers distinct and complementary pathways that tightly coordinate microtubule capture and microtubule stability to control chemotaxis.

  17. Grain growth kinetics for B2O3-doped ZnO ceramics

    Directory of Open Access Journals (Sweden)

    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.

  18. The Interface of TiB2 and Al3Ti in Molten Aluminum

    Science.gov (United States)

    Wang, Xiaoming; Song, Jie; Vian, Wei; Ma, Haibin; Han, Qingyou

    2016-12-01

    In the grain refinement of aluminum, Al3Ti and TiB2 particles are introduced to reduce the casting grain size down to 200 micrometer level, which makes cold working possible. The particles are brought in by the addition of Al-Ti-B-type master alloys. It is generally believed that TiB2 particles are stable and nucleate α-Al grains in solidification in the presence of titanium in solution from the dissolution of Al3Ti particles in the master alloys. The titanium in solution either forms Al3Ti layers on the surface of TiB2 particles to promote the nucleation of α-Al grains or remains as solute to restrict the growth of α-Al grains in solidification. However, a consensus on a grain refinement mechanism is still to be reached due to the lack of direct observation of the three phases in castings. This paper presents finding of the TiB2/Al3Ti interfaces in an Al-Ti-B master alloy. It demonstrates a strong epitaxial growth of Al3Ti on the surface of TiB2 particles, a sign of the formation of an Al3Ti layer on the surface of TiB2 particles in grain refinement practice. The Al3Ti layer has a crystal coherency with α-Al and hence offers a substrate for heterogeneous nucleation of α-Al grains. However, the layer must be dynamic to avoid the formation of compounded Al3Ti and TiB2 particles leading to the loss of efficiency in grain refinement.

  19. Procyanidin B2 cytotoxicity to MCF-7 human breast adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Monalisa M Avelar

    2012-01-01

    Full Text Available Procyanidins have attracted some attention due to their demonstrated chemopreventive action, a relatively new and promising strategy to prevent cancer. Breast cancer is one of the leading causes of death in women worldwide and its treatment needs improvements. The aim of this work was to verify the procyanidin dimmer B2 cytotoxic effect to MCF-7 human breast cancer cells. MCF-7 cells were cultured in RPMI medium, containing 20% fetal bovine serum and antibiotics in a CO 2 chamber. The cells were treated with different concentrations of B2 and its cytotoxic potential was assessed by the sulforhodamine B assay, morphologically through haematoxylin-eosin staining and by DNA fragmentation analysis. The significance of differences between experimental conditions was determined using the ANOVA test, followed by the Tukey test when P<0.05. Cell proliferation decreased in a concentration and time-dependent manner upon procyanidin dimmer B2 treatment, being 19.20 μM the IC 50 . Procyanidin dimmer B2 treatment displayed concentration and time-dependent decline in MCF-7 cells compared to control and also induced morphological alterations compatible with cell-death induction. Cell condensation and cell diameter decreased (3.5 folds compared to control cells, after 48 h cell-exposure to 50 μM procyanidin dimmer B2, but the DNA ladder formation was not observed. In conclusion, our results demonstrated that procyanidin dimmer B2 exhibits cytotoxic activity to MCF-7 cells and it could be a potential antineoplastic agent. Further studies are necessary to clarify the procyanidin dimmer B2 mechanism of action. The evaluation of biological efficacy of individual components is an important step towards drug discovery and development.

  20. Action Irmpd Spectroscopy of B_2 Fragment Ions from Qaxig and Naxig Pentapeptides

    Science.gov (United States)

    Morrison, L.; Chamot-Rooke, J.; Wysocki, V.

    2013-06-01

    The N-terminal fragments of peptides in MS/MS studies, or "b" ions, have been the subject of controversy for many years. The result of amide bond cleavage, these ions can be generated by two main pathways, forming either a head-to-tail cyclic peptide or a 5-membered oxazolone ring structure. The b_2 ion is particularly interesting because the head-to-tail isomer, or diketopiperazine, is typically more stable than the oxazolone but requires a high energy trans-cis isomerization of the peptide bond in order to form. Although amino acid identity in the first two positions is known to influence diketopiperazine vs. oxazolone formation, the factors that influence diketopiperazine formations are still incompletely understood. Action IRMPD (infrared multi-photon dissociation) spectroscopy was used to interrogate the gas-phase structures of the b_2 ions from QAXIG and NAXIG (X = L, D, or E) peptides. Irradiation of b_2 ions in the 1000 to 2000 cm^{-1} range interrogates the amide, amine, and carbonyl vibrational modes characteristic of diketopiperazine and oxazolone b_2 ions. Examination of the b_{2} structures of QAXIG and NAXIG peptides by this strategy has yielded novel information regarding the formation pathway of the diketopiperazine structure in the gas phase. Peptides without a basic residue in one of the first two positions are shown to generate diketopiperazine b_2 ions, which suggests that a bridging side chain is critical for b_2 ion formation by this pathway. Moreover, the third residue is shown for the first time to play a role in discriminating between the oxazolone and diketopiperazine product ions.

  1. Brazilian multipurpose reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Brazilian Multipurpose Reactor (RMB) Project is an action of the Federal Government, through the Ministry of Science Technology and Innovation (MCTI) and has its execution under the responsibility of the Brazilian National Nuclear Energy Commission (CNEN). Within the CNEN, the project is coordinated by the Research and Development Directorate (DPD) and developed through research units of this board: Institute of Nuclear Energy Research (IPEN); Nuclear Engineering Institute (IEN); Centre for Development of Nuclear Technology (CDTN); Regional Center of Nuclear Sciences (CRCN-NE); and Institute of Radiation Protection and Dosimetry (IRD). The Navy Technological Center in Sao Paulo (CTMSP) and also the participation of other research centers, universities, laboratories and companies in the nuclear sector are important and strategic partnerships. The conceptual design and the safety analysis of the reactor and main facilities, related to nuclear and environmental licensing, are performed by technicians of the research units of DPD / CNEN. The basic design was contracted to engineering companies as INTERTHECNE from Brazil and INVAP from Argentine. The research units from DPD/CNEN are also responsible for the design verification on all engineering documents developed by the contracted companies. The construction and installation should be performed by specific national companies and international partnerships. The Nuclear Reactor RMB will be a open pool type reactor with maximum power of 30 MW and have the OPAL nuclear reactor of 20 MW, built in Australia and designed by INVAP, as reference. The RMB reactor core will have a 5x5 configuration, consisting of 23 elements fuels (EC) of U{sub 3}Si{sub 2} dispersion-type Al having a density of up to 3.5 gU/cm{sup 3} and enrichment of 19.75% by weight of {sup 23{sup 5}}U. Two positions will be available in the core for materials irradiation devices. The main objectives of the RMB Reactor and the other nuclear and radioactive

  2. Modeling Chemical Reactors I: Quiescent Reactors

    CERN Document Server

    Michoski, C E; Schmitz, P G

    2010-01-01

    We introduce a fully generalized quiescent chemical reactor system in arbitrary space $\\vdim =1,2$ or 3, with $n\\in\\mathbb{N}$ chemical constituents $\\alpha_{i}$, where the character of the numerical solution is strongly determined by the relative scaling between the local reactivity of species $\\alpha_{i}$ and the local functional diffusivity $\\mathscr{D}_{ij}(\\alpha)$ of the reaction mixture. We develop an operator time-splitting predictor multi-corrector RK--LDG scheme, and utilize $hp$-adaptivity relying only on the entropy $\\mathscr{S}_{\\mathfrak{R}}$ of the reactive system $\\mathfrak{R}$. This condition preserves these bounded nonlinear entropy functionals as a necessarily enforced stability condition on the coupled system. We apply this scheme to a number of application problems in chemical kinetics; including a difficult classical problem arising in nonequilibrium thermodynamics known as the Belousov-Zhabotinskii reaction where we utilize a concentration-dependent diffusivity tensor $\\mathscr{D}_{ij}(...

  3. Alternative approaches to fusion. [reactor design and reactor physics for Tokamak fusion reactors

    Science.gov (United States)

    Roth, R. J.

    1976-01-01

    The limitations of the Tokamak fusion reactor concept are discussed and various other fusion reactor concepts are considered that employ the containment of thermonuclear plasmas by magnetic fields (i.e., stellarators). Progress made in the containment of plasmas in toroidal devices is reported. Reactor design concepts are illustrated. The possibility of using fusion reactors as a power source in interplanetary space travel and electric power plants is briefly examined.

  4. Theoretical investigation of superconductivity in MgB2-xCx alloys

    Science.gov (United States)

    Sharma, Gargee; Sharma, Smita

    2016-05-01

    In this paper we investigated the superconducting properties of MgB2-xCx alloys where x is the concentration (0.0, 0.03, 0.11 and 0.20). The superconducting state parameters, namely, the electron-phonon coupling strength (λ), Coulomb pseudopotential (μ*), transition temperature (Tc), isotope effect exponent (α) and interaction strength (NoV) of MgB2-xCx alloys have been investigated in the BCS-Eliashberg-McMillan framework, as modified for MgB2-xCx alloys. Pseudo ions with average properties have been considered to replace different types of ions in the system. It is observed that all the superconducting parameters go on decreasing as the concentration of C is increased. The magnitudes of λ and Tc indicate that MgB2-xCx is strong-to-intermediate coupling superconductor. It is also observed that Tc is composition dependent. Present computations yield almost linear variation of Tc with concentration x of C in the MgB2-xCx system, which is in agreement with the experimental data. A linear Tc equation is proposed by fitting the present results.

  5. The phase analysis of spark plasma sintered MgB2 after ball milling.

    Science.gov (United States)

    Kang, Deuk-Kyun; Kim, Dong-Woong; Kim, Cheol-Jin; Ahn, In-Shup

    2010-01-01

    Mg and amorphous B powders below 10 and 3 micro meter were used as raw materials, and mixed by planetary-mill for 9 hours at argon atmosphere. MgB2 bulk was fabricated at the various temperatures by Spark Plasma Sintering. In the sintering process, mixed powders were sintered in graphite mold, at the pressure of 55 Mpa. The fabricated MgB2 samples were evaluated with XRD, EDS, FE-SEM, PPMS. MgB2, MgO and Fe phases were observed from XRD result. In the results, MgO and Fe were impurity which may affect superconducting properties of MgB2 samples, and it's distribution could be confirmed from EDS mapping result. In order to confirm the formation of MgB2 phase, DTA was used as heating rate of 10 degrees C/min at Ar atmosphere from room temperature to 1200 degrees C. In the PPMS result, the Tc (critical temperature) was about 21 K, and the density of spark plasma sintered samples increased to 1.87 g/cm3 by increasing sintering temperature.

  6. Evaluations of MgB2 Coatings on 2'' Copper Discs for Superconducting Radio Frequency Applications

    Science.gov (United States)

    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.

  7. MgB2超导线材的机械性能

    Institute of Scientific and Technical Information of China (English)

    冯建情

    2007-01-01

    尽管MgB2超导线材的临界转变温度相对较低,但MgB2没有晶界弱连接,因而具有低的加工成本,相对于BSCCO和YBCO表现出明显的应用优势。目前,粉末装管技术(PIT)广泛用于制备MgB2带材和线材。利用高能球磨工艺的超细粉末制备的MgB2线材临界电流密度达到3.0×105A/cm2(20K,自场)。为了了解MgB2线材的实际使用条件和提高使用条件下的性能,很有必要对其进行机械性能方面的研究。

  8. MgB2超导线材的机械性能

    Institute of Scientific and Technical Information of China (English)

    冯建情

    2007-01-01

    @@ 尽管MgB2超导线材的临界转变温度相对较低,但MgB2没有晶界弱连接,因而具有低的加工成本,相对于BSCCO和YBCO表现出明显的应用优势.目前,粉末装管技术(PIT)广泛用于制备MgB2带材和线材.利用高能球磨工艺的超细粉末制备的MgB2线材临界电流密度达到3.0×105 A/cm2(20 K,自场).为了了解MgB2线材的实际使用条件和提高使用条件下的性能,很有必要对其进行机械性能方面的研究.

  9. MgB2超导体的正电子湮没研究

    Institute of Scientific and Technical Information of China (English)

    葛永霞; 常方高; 李涛; 路庆凤; 李喜贵

    2005-01-01

    本文利用正电子湮没技术(PAT)对不同密度的MgB2样品分别进行了测定,结果发现正电子在MgB2中自由态的湮没时间(本征寿命τ1)和在捕获态的湮没时间(缺陷寿命τ2)比其他高温超导体都明显要高,这反映了MgB2的体电子浓度相对于其它超导体要低,可能归因于MgB2超导材料本身的晶体结构和化学组成,MgB2超导材料的正电子寿命不仅与晶体的结构缺陷,而且与样品的密度或孔隙度有关.

  10. PREPARATION AND CHARACTERISTICS OF MgB2-B-MgB2 JOSEPHSON JUNCTION ON Si(111)SUBSTRATE%硅衬底MgB2-B-MgB2超导SNS约瑟夫森结的制备与特性

    Institute of Scientific and Technical Information of China (English)

    柯一青; 周迪帆; 刘珏; 曾敏; 朱红妹; 张义邴

    2009-01-01

    利用两步原位电子束蒸发技术,在Si(111)衬底上制备了MgB2-B-MgB2超导SNS约瑟夫森夹心结.夹心硼(B)层厚度从10nm到80nm范围内MgB2-B-MgB2/Si(111)薄膜表现出明显的SNS约瑟夫森结特性,而在5nm和100nm处薄膜分别是整体超导和正常金属特性.在同一温度下,随着硼层厚度的增加,临界结电流减小,对同一厚度下,临界结电流随着温度的增加而减小.同时,实验指出,夹心硼SNS超导MgB2约瑟夫森结的电流-电压(I-V)曲线具有回滞现象,符合SM模型.

  11. SYNTHESIS AND THERMAL STABILITY OF NANOCOMPOSITE nc-TiN/a-TiB2 THIN FILMS

    Institute of Scientific and Technical Information of China (English)

    Y.H. Lu; Z.F. Zhou; P. Sit; Y.G. Shen; K.Y. Li; H. Chen

    2005-01-01

    Several nc-TiN/a-TiB2 thin films comprised of nanocrystalline (nc-) TiN and amorphous (a-) TiB2phases were deposited on Si(100)at room temperature by reactive unbalanced dc magnetron sputtering, followed by vacuum annealed at 400, 600, 800 and 1000℃ for 1h, respectively. Effects of B content on microstructure, mechanical behaviors and thermal microstructure stability have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and nanoindentation measurements. The results indicated that B addition greatly affected both microstructure and mechanieal behavior of nc-TiN/a-TiB2 thin films. With increasing B content the grain size decreased. A maximum hardness value of about 33GPa was obtained at B content of about 19at. %. The improved mechanical properties of nc-TiN/a-TiB2films with the addition of B into TiN were attributed to their densified microstructure with development of fine grain size. Only addition of sufficient B could restrain grain growth during annealing. High B content resulted in high microstructure stability. The crystallization of amorphous matrix occurred at about 800℃, forming TiB or TiB2 crystallite, depending on B content. Before that no change in bonding configuration was found.

  12. Electrochemical Oxidation of Paracetamol Mediated by MgB2 Microparticles Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Mohammed Zidan

    2011-01-01

    Full Text Available A MgB2 microparticles modified glassy carbon electrode (MgB2/GCE was fabricated by adhering microparticles of MgB2 onto the electrode surface of GCE. It was used as a working electrode for the detection of paracetamol in 0.1 M KH2PO4 aqueous solution during cyclic voltammetry. Use of the MgB2/GCE the oxidation process of paracetamol with a current enhancement significantly by about 2.1 times. The detection limit of this modified electrode was found to be 30 μM. The sensitivity under conditions of cyclic voltammetry is significantly dependent on pH, supporting electrolyte, temperature and scan rate. The current enhancement observed in different electrolytic media varied in the following order: KH2PO4 > KCl > K2SO4 > KBr. Interestingly, the oxidation of paracetamol using modified GC electrode remain constant even after 15 cycling. It is therefore evident that the MgB2 modified GC electrode possesses some degree of stability. A slope of 0.52 dependent of scan rate on current indicates that the system undergoes diffusion-controlled process.

  13. Abbreviated New Drug Applications and 505(b)(2) Applications. Final rule.

    Science.gov (United States)

    2016-10-06

    The Food and Drug Administration (FDA, the Agency, or we) is issuing a final rule to implement Title XI of the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA), which amended provisions of the Federal Food, Drug, and Cosmetic Act (the FD&C Act) that govern the approval of 505(b)(2) applications and abbreviated new drug applications (ANDAs). This final rule implements portions of Title XI of the MMA that pertain to provision of notice to each patent owner and the new drug application (NDA) holder of certain patent certifications made by applicants submitting 505(b)(2) applications or ANDAs; the availability of 30-month stays of approval on 505(b)(2) applications and ANDAs that are otherwise ready to be approved; submission of amendments and supplements to 505(b)(2) applications and ANDAs; and the types of bioavailability and bioequivalence data that can be used to support these applications. This final rule also amends certain regulations regarding 505(b)(2) applications and ANDAs to facilitate compliance with and efficient enforcement of the FD&C Act.

  14. The role of various boron precursor on superconducting properties of MgB2/Fe

    Science.gov (United States)

    Safran, S.; Kılıçarslan, E.; Kılıç, A.; Gencer, A.

    2014-09-01

    The superconducting properties of Fe sheathed MgB2 wire has been studied as a function of precursor B powder particle size. The in situ processed MgB2 samples were prepared by means of conventional solid state reaction method with magnesium powder (99.8%, 325 mesh) and three different types of amorphous boron powders (purity; 98.8%, >95% and 91.9%) from two sources, Pavezyum (Turkish supplier) and Sigma Aldrich. The particle sizes of Turkish boron precursor powder were selected between 300 and 800 nm. The structural and magnetic properties of the prepared samples were investigated by means of the X-ray powder diffraction (XRD) and ac susceptibility measurements. The XRD patterns showed that the diffraction peaks for our samples belong to the main phase of the MgB2 diffraction patterns. The highest critical temperature, Tc = 38.4 K was measured for the MgB2 sample which was fabricated by using the 98.8% B. The critical current density of this sample was extracted from the magnetization measurements and Jc = 5.4 × 105 A cm-2 at 5 K and B = 2 T. We found that the sample made by using the 98.8% boron showed almost 2 times higher Jc than that of obtained from 91.9% B powder.

  15. Fabrication of Homogenous Dispersion TiB2-Al2O3 Composites

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jinyong; TANG Wenjun; FU Zhengyi; WANG Weiming; ZHANG Qingjie

    2011-01-01

    In order to get a homogenous mixture and compact of TiB2-A12O3,hybridization as a surface modification method was used to prepare nano-scale Al2O3 coated TiB2 particles.PE-wax particles were first coated onto TiB2 particles by hybridization,and then the nano-scale Al2O3 particles were coated onto the surface of TiB2 coated by PE-wax particles again.SEM,TEM and EDS were used to characterize the microstructure of as-received core/shell particles and its compacts.The experimental results show that a particle-scale homogenous dispersion of TiB2 and Al2O3 can be formed not only in mixed powder but also in dewaxed compacts.The compacts then were sintered by gas-pressing sintering(GPS).Finial products show improved mechanic properties comparing with reference samples fabricated by normal ways.

  16. ErbB2 and bone sialoprotein as markers for metastatic osteosarcoma cells

    Science.gov (United States)

    Valabrega, G; Fagioli, F; Corso, S; Madon, E; Brach del Prever, A; Biasin, E; Linari, A; Aglietta, M; Giordano, S

    2003-01-01

    Osteosarcoma is the most common malignant bone neoplasia occurring in young patients in the first two decades of life, and represents 20% of all primitive malignant bone tumours. At present, treatment of metastatic osteosarcoma is unsatisfactory. High-dose chemotherapy followed by CD34+ leukapheresis rescue may improve these poor results. Neoplastic cells contaminating the apheresis may, however, contribute to relapse. To identify markers suitable for detecting osteosarcoma cells in aphereses we analysed the expression of bone-specific genes (Bone Sialoprotein (BSP) and Osteocalcin) and oncogenes (Met and ErbB2) in 22 patients with metastatic osteosarcoma and six healthy stem cell donors. The expression of these genes in aphereses of patients affected by metastatic osteosarcoma was assessed by RT–PCR and Southern blot analysis. Met and Osteocalcin proved to be not useful markers since they are positive in aphereses of both patients with metastatic osteosarcoma and healthy stem cell donors. On the contrary, BSP was expressed at significant levels in 85% of patients. Moreover, 18% of patients showed a strong and significantly positive (seven to 16 times higher than healthy stem cell donors) ErbB2 expression. In all positive cases, neoplastic tissue also expressed ErbB2. Our data show that ErbB2 can be a useful marker for tumour contamination in aphereses of patients affected by ErbB2-expressing osteosarcomas and that analysis of Bone Sialoprotein expression can be an alternative useful marker. PMID:12569382

  17. Apoptosis induced by boric anhydrite (B2O3) after partial hepatectomy in rat liver.

    Science.gov (United States)

    Ozen, A; Canbek, M

    2016-01-01

    Boron is one of the important elements that have a cell-growth suppressing effect. The apoptotic effects of B(2)O(3) that were investigated in rats on liver regeneration following 70 % partial hepatectomy (PH). Wistar albino male rats were used and divided into 4 groups (n = 7). The Saline control groups were given only a single dose of saline; the B(2)O(3)-treated groups that were only given a single dose of 1800 mg.kg(-1) B(2)O(3) by means of intraperitoneal injections following hepatectomy. Three and 6 hours after surgical procedures, all the groups were dissected and liver tissue samples were taken from the groups for NF-κB for caspase-3 gene and protein levels investigation by RT-PCR and TaqMan Protein Assay and histological analyses by TUNEL assay. B(2)O(3)-treated animals were examined and it was observed that NF-κB levels were decreased; however, caspase-3 gene expression and protein levels were increased significantly. This study demonstrated that B(2)O(3) induces caspase-3 and inhibits NF-κB at the early stage of liver regeneration (Fig. 4, Ref. 26).

  18. Synthesis of TiB2 nanocrystalline powder by mechanical alloying

    Institute of Scientific and Technical Information of China (English)

    TANG Wen-ming; ZHENG Zhi-xiang; WU Yu-cheng; WANG Jian-min; L(U) Jun; LIU Jun-wu

    2006-01-01

    TiB2 nanocrystalline powder was synthesized by mechanical alloying of Ti-67B elemental powder. X-ray diffraction(XRD)and transmission electron microscopy(TEM) were used to study the structural evolution of the powder during ball milling. The effects of heat treatment on the structural evolution and thermal stability of the mechanically alloyed(MAed) Ti-67B powder were also discussed. During ball milling the Ti-67B powder, a solid solution of B in Ti, Ti(B) is firstly formed. When the powder is milled for 10 h, the amorphous transition of Ti(B) from the crystalline to the amorphous phase occurs. When the powder is milled for 20 h,nanocrystalline TiB2 is formed from the amorphous Ti(B). When the powder is milled for 60 h, only TiB2 is detected with grain size of 10 nm. The formation of TiB2 nanocrystalline is controlled by the gradual diffusion reaction mechanism. During heat-treatment of the MAed Ti-67B powder, the structural changes of TiB2, including grain growth and lattice ordering degree increasing may occur.

  19. Supporting the Health Quality Measures Format in i2b2.

    Science.gov (United States)

    Klann, Jeffrey G; Murphy, Shawn N

    2013-01-01

    The Health Quality Measures Format (HQMF) is an HL7 standard for expressing computable queries of clinical data. It is becoming increasingly consequential for both quality measurement and population health research. A variety of national leadership is involved in its development and deployment, including the Meaningful Use incentive program, the Query Health initiative, the Joint Commission, the National Quality Forum (NQF), and the Food and Drug Administration. Here we analyze the structure of HQMF and apply this to computation of HQMF on Informatics for Integrating Biology and the Bedside (i2b2). i2b2 is a widely used, modular, open-source clinical research data repository. We implement a translator to convert between HQMF and i2b2-XML format that covers the subset of HQMF supported in i2b2-XML, which will be expanded in the next release of i2b2. This translator is part of the freely-available reference implementation of the QueryHealth initiative.

  20. Reactor monitoring using antineutrino detectors

    Science.gov (United States)

    Bowden, N. S.

    2011-08-01

    Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactor as part of International Atomic Energy Agency (IAEA) and/or other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway worldwide.

  1. Reactor vessel support system. [LMFBR

    Science.gov (United States)

    Golden, M.P.; Holley, J.C.

    1980-05-09

    A reactor vessel support system includes a support ring at the reactor top supported through a box ring on a ledge of the reactor containment. The box ring includes an annular space in the center of its cross-section to reduce heat flow and is keyed to the support ledge to transmit seismic forces from the reactor vessel to the containment structure. A coolant channel is provided at the outside circumference of the support ring to supply coolant gas through the keyways to channels between the reactor vessel and support ledge into the containment space.

  2. 78 FR 46854 - Mixed Straddles; Straddle-by-Straddle Identification Under Section 1092(b)(2)(A)(i)(I)

    Science.gov (United States)

    2013-08-02

    ... Under Section 1092(b)(2)(A)(i)(I) AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice of... identification under section 1092(b)(2)(A)(i)(I). [The text of the proposed amendments to Sec....

  3. 78 FR 46807 - Mixed Straddles; Straddle-by-Straddle Identification Under Section 1092(b)(2)(A)(i)(I)

    Science.gov (United States)

    2013-08-02

    ... Under Section 1092(b)(2)(A)(i)(I) AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Temporary... straddles; straddle-by-straddle identification under section 1092(b)(2)(A)(i)(I) (Temporary). * * * * *...

  4. Methanogenesis in Thermophilic Biogas Reactors

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær

    1995-01-01

    Methanogenesis in thermophilic biogas reactors fed with different wastes is examined. The specific methanogenic activity with acetate or hydrogen as substrate reflected the organic loading of the specific reactor examined. Increasing the loading of thermophilic reactors stabilized the process...... as indicated by a lower concentration of volatile fatty acids in the effluent from the reactors. The specific methanogenic activity in a thermophilic pilot-plant biogas reactor fed with a mixture of cow and pig manure reflected the stability of the reactor. The numbers of methanogens counted by the most...... against Methanothrix soehngenii or Methanothrix CALS-I in any of the thermophilic biogas reactors examined. Studies using 2-14C-labeled acetate showed that at high concentrations (more than approx. 1 mM) acetate was metabolized via the aceticlastic pathway, transforming the methyl-group of acetate...

  5. Properties Of MgB2/Ga Composites Prepared By Mechanical Alloying

    Directory of Open Access Journals (Sweden)

    Yoon K.

    2015-06-01

    Full Text Available In this study, we examined the effect of Ga-doping and mechanical alloying in MgB2 on microstructural and phase evolution. A comparison was made between in-situ and ex-situ processed Mg-B-Ga samples. Densification was markedly improved by ex-situ sintering of ball-milled MgB2+Ga. The Ga-doping and ball-milling prior to sintering resulted in the formation of impurity phases such as MgO, Ga5Mg2 and Ga2O3. Lattice parameter of MgB2 increased with increasing ball-milling duration as well as by Ga-doping.

  6. Definitive experimental evidence for two-band superconductivity in MgB2.

    Science.gov (United States)

    Tsuda, S; Yokoya, T; Takano, Y; Kito, H; Matsushita, A; Yin, F; Itoh, J; Harima, H; Shin, S

    2003-09-19

    The superconducting-gap of MgB2 has been studied by high-resolution angle-resolved photoemission spectroscopy. The results show that superconducting gaps with values of 5.5 and 2.2 meV open on the sigma band and the pi band, respectively, but both the gaps close at the bulk transition temperature, providing a definitive experimental evidence for the two-band superconductivity with strong interband pairing interaction in MgB2. The experiments validate the role of k-dependent electron-phonon coupling as the origin of multiple-gap superconductivity as well as the high transition temperature of MgB2.

  7. Three-dimensional MgB2-type superconductivity in hole-doped diamond.

    Science.gov (United States)

    Boeri, Lilia; Kortus, Jens; Andersen, O K

    2004-12-01

    We substantiate by numerical and analytical calculations that the recently discovered superconductivity below 4 K in 3% boron-doped diamond is caused by electron-phonon coupling of the same type as in MgB2, albeit in three dimensions. Holes at the top of the zone-centered, degenerate sigma-bonding valence-band couple strongly to the optical bond-stretching modes. The increase from two to three dimensions reduces the mode softening crucial for T(c) reaching 40 K in MgB2. Even if diamond had the same bare coupling constant as MgB2, which could be achieved with 10% doping, T(c) would be only 25 K. Superconductivity above 1 K in Si (Ge) requires hole doping beyond 5% (10%).

  8. Anisotropy of superconducting MgB2 as seen in electron spin resonance and magnetization data.

    Science.gov (United States)

    Simon, F; Jánossy, A; Fehér, T; Murányi, F; Garaj, S; Forró, L; Petrovic, C; Bud'ko, S L; Lapertot, G; Kogan, V G; Canfield, P C

    2001-07-23

    We observed the conduction electron spin resonance (CESR) in fine powders of MgB2 both in the superconducting and normal states. The Pauli susceptibility is chi(s) = 2.0 x 10(-5) emu/mole in the temperature range of 450 to 600 K. The spin relaxation rate has an anomalous temperature dependence. The CESR measured below T(c) at several frequencies suggests that MgB2 is a strongly anisotropic superconductor with the upper critical field, H(c2), ranging between 2 and 16 T. The high-field reversible magnetization data of a randomly oriented powder sample are well described assuming that MgB2 is an anisotropic superconductor with H(ab)(c2)/H(c)(c2) approximately 6-9.

  9. Magnetization and electric transport properties of single-crystal MgB2 nanowires.

    Science.gov (United States)

    Wu, Cen-Shawn; Chang, Yu-Cheng; Chen, Weimeng; Chen, Chinping; Feng, Qingrong

    2012-11-23

    High quality single-crystal magnesium diboride (MgB(2)) nanowires with lengths exceeding 10 μm were successfully synthesized by hybrid physical chemical vapor deposition. The magnetization and electrical transport properties of single-crystal MgB(2) nanowires (NWs) were measured. The superconducting transition temperature of the NWs was 37 K, as confirmed by magnetization measurements. The disordered behavior of the nanowires was observed by four-terminal current-voltage characteristic measurements of an individual NW from T = 10 to 300 K. The temperature-dependent resistivity curves for seven NWs collapsed into a universal curve described by the variable range hopping model, showing intrinsic nonmetallic transport properties. This implies that the granular superconducting defect states are critical to the superconductivity of the individual MgB(2) NWs.

  10. Vitamin B2 content determination in liver paste by using acid and acid-enzyme hydrolysis

    Directory of Open Access Journals (Sweden)

    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

  11. Continuum observation of Sagittarius B2 at 23 and 43 GHz

    Science.gov (United States)

    Akabane, Kenji; Sofue, Yoshiaki; Hirabayashi, Hisashi; Morimoto, Masaki; Inoue, Makoto

    The source Sgr B2 has been mapped with a single-dish resolution of ≡40arcsec at frequencies of 23 GHz and 43 GHz. An extended thermal component was found, and has been compared with that in lower frequency observations. The core region of Sgr B2 (containing the compact sources MD4 and MD5) was resolved at both 23 GHz and 43 GHz. The compact components MD4 and MD5 have complex thermal spectra which may indicate inhomogeneities within each compact core. A new source, G0.64-0.06, was found in the southern area of the extended thermal component. The 43-GHz map made with the Nobeyama 45-m telescope was compared with a 10.7-GHz map made with the Effelsberg 100-m telescope. This comparison suggests that there may be some nonthermal emission in the southern area of Sgr B2.

  12. Fabrication of TiB2 composite powders coated with BN by high speed airflow impact

    Institute of Scientific and Technical Information of China (English)

    FENG Cai-mei; WANG Wei-min; FU Zheng-yi

    2005-01-01

    TiB2 powders coated with BN were prepared by Hybridization System making use of dry impact blending method to achieve powder surface modification. Parameters of coating were analyzed and the most appropriate condition was summarized. Scan electron microscope of JSM-5610LV and transmission electron microscope of H600STEM/EDS were used to observe the microstructure of coated powders. Results show that treatment time, rotation speed, granularity ratio of TiB2 to BN, pretreatment of materials etc influence the coating results evidently.Mixing raw materials and coating with BN under the appropriate condition can get round TiB2/BN composite powder with smooth surface and compact coating layer.

  13. Magnetic properties of Y1- xGdxCo2B2C series of borocarbides

    Science.gov (United States)

    Bud'ko, S. L.; Giordanengo, B.; Sulpice, A.; Fontes, M. B.; Baggio-Saitovitch, E. M.

    1995-04-01

    Magnetic properties of Y1- xGdxCo2B2C series of compounds were studied. Two magnetically ordered phases were observed for 0.7 ≤ x ≤ 1. Change of the magnetic ordering temperatures T 1 and T 2 with the Gd concentration is argued to be related to the dilution of magnetic Gd by nonmagnetic Y and to the reduction of the distance between ( Y1- xGdx) C planes. However, significant contribution to the changes in T 1 between pure GdNi2B2C and GdCo2B2C samples is suggested to be due to the different 3 d band filling in these compounds.

  14. Wetting of microstructured alumina fabricated by epitaxial growth of Al4B2O9 whiskers

    Science.gov (United States)

    Wang, Yifeng; Feng, Jicai; Chen, Zhe; Song, Xiaoguo; Cao, Jian

    2015-12-01

    Topographical microstructures were fabricated on alumina by epitaxial growth of Al4B2O9 whiskers in air. The products were characterized via scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The whiskers were found to grow along the [0 0 1] crystallographic direction, and the lattice mismatch between Al2O3 and Al4B2O9 was determined to be 0.03%. The wetting of the Al4B2O9-whisker-coated surfaces by Ag-36.7Cu-8.0Ti at.% alloy was studied. The time needed to reach the equilibrium stage reduced as the temperature increased, and the final contact angle for liquid alloy on the rough surface was 27° at 880 °C. The wetting dynamics of the whiskers coated surfaces was investigated. After wetting, a whisker-interconnected region was formed between alumina and the alloy.

  15. Preparation of TiB2 Coated Cathode of Al Electrolysis

    Institute of Scientific and Technical Information of China (English)

    Bing LI; Fei ZHOU; Zhuxian QIU

    2001-01-01

    TiB2 coating was prepared by electrodeposition from KCl-KF-K2TiF6-KBF4 molten salts on graphite substrate at 810℃. The coating is affected by protective gas, current density, and electrolyte compositions. From a series of tests it can be concluded that when the following conditions are used, TiB2 coating will be compact and homogeneous, and the layer of coating has higher TiB2 content, and also hasgood coherence to graphite matrix. The electrolysis conditions are as follows: KCI 5%, KF 60~70%, K2TiF6 10%, KBF4 20~30%, (mole fraction),current density being 0.4~0.8 A/cm2 and Ar being used as protective gas.

  16. Design Aspects on Winding of an MgB2 Superconducting Generator Coil

    DEFF Research Database (Denmark)

    Magnusson, N.; Eliassen, J.C.; Abrahamsen, Asger Bech

    2015-01-01

    Generators based on superconducting rotor coils are considered for future large off-shore wind turbines for their low weight and compact design, and for their possibility to reduce costs. In the 10-20 K temperature range, MgB2 superconductors carry current densities 100 times higher than standard...... copper conductors at room temperature at one tenth of the wire cost per unit carried current. In the framework of the European project INNWIND.EU, an MgB2 superconducting generator pole will be designed, built and tested. Some of the design aspects of this work with emphasis on the winding process......% compared to the use of an additional, dedicated, electrical insulation like Kapton for wet-winding or glass-fibre for dry-winding followed by vacuum impregnation. We show the results of a trial winding of 500 m of MgB2 superconducting wire into a double pancake coil using the wet-winding technique...

  17. Phase formation of superconducting MgB2 at ambient pressure

    Indian Academy of Sciences (India)

    A Talapatra; S K Bandyopadhyay; Pintu Sen; A Sarkar; P Barat

    2004-10-01

    MgB2 superconductor has been synthesized using a simple technique at ambient pressure. The synthesis was carried out in helium atmosphere over a wide range of temperatures. Magnesium was employed in excess to the stoichiometry to prevent the decomposition of MgB2. Samples of MgB2 thus prepared have been almost free from MgO as compared to other methods. Resistivities of the samples are quite low with residual resistivity ratio (RRR) of around 3. c ( = 0) is 38.2–38.5 K with c of 0.6–1.0 K. Comparative studies of various methods of low pressure synthesis have been presented.

  18. Galactomannan Downregulates the Inflammation Responses in Human Macrophages via NFκB2/p100

    Directory of Open Access Journals (Sweden)

    Víctor Toledano

    2015-01-01

    Full Text Available We show that galactomannan, a polysaccharide consisting of a mannose backbone with galactose side groups present on the cell wall of several fungi, induces a reprogramming of the inflammatory response in human macrophages through dectin-1 receptor. The nuclear factor kappa-light-chain-enhancer of activated B cells 2 (NFκB2/p100 was overexpressed after galactomannan challenge. Knocking down NFκB2/p100 using small interfering RNA (siRNA indicated that NFκB2/p100 expression is a crucial factor in the progression of the galactomannan-induced refractoriness. The data presented in this study could be used as a modulator of inflammatory response in clinical situations where refractory state is required.

  19. The role of MgO content in ex situ MgB2 wires

    DEFF Research Database (Denmark)

    Kovac, P.; Hugek, I.; Meligek, T.;

    2004-01-01

    An experimental study of the effect of MgO content in the MgB2 powder used for ex situ made composite wires was carried out. Two single-core MgB2/Fe/Cu wires were made using commercial MgB2 powders from Alfa Aesar containing different fraction of MgO. Critical temperature and critical currents...... of as-deformed and heat-treated wires were measured. The differences between the wires are discussed and correlated with the MgO content. It was found that by increasing the amount of MgO, the inter-grain connectivity worsens, but well distributed and low size MgO particles improve flux pinning....

  20. Transmembrane Domain Targeting Peptide Antagonizing ErbB2/Neu Inhibits Breast Tumor Growth and Metastasis

    Directory of Open Access Journals (Sweden)

    Alexia Arpel

    2014-09-01

    Full Text Available Breast cancer is still a deadly disease despite major achievements in targeted therapies designed to block ligands or ligand-binding subunits of major tyrosine kinase receptors. Relapse is significant and metastases deleterious, which demands novel strategies for fighting this disease. Here, we report a proof-of-concept experiment demonstrating that small peptides interfering with the transmembrane domain of the tyrosine kinase epidermal growth factor receptor ErbB2 exhibit anticancer properties when used at micromolar dosages in a genetically engineered mouse model of breast cancer. Different assays demonstrate the specificity of the ErbB2-targeting peptide, which induces long-term reduction of ErbB2 phosphorylation and Akt signaling consistent with reduced tumor cell proliferation and increased survival. Microcomputed tomography analysis established the antimetastatic activity of the peptide and its impact on primary tumor growth. This reveals the interior of the cell membrane as an unexplored dimension for drug design.

  1. Extinction coefficient of H2CC(3B2) at 137 nm

    Science.gov (United States)

    Fahr, A.; Laufer, A. H.

    1985-01-01

    In spite of the conduction of numerous studies regarding the vinylidene free radical, its role and importance as a reactive intermediate is not well characterized. Laufer (1980, 1983) has reported the absorption spectrum of metastable H2CC(3B2), the lowest excited state, in the vacuum ultraviolet and has measured several aspects of its quenching properties. The present study provides a measurement of the extinction coefficient of H2CC(3B2). Knowledge of the vinylidene concentration is required to convert readily available absorption data into an extinction coefficient or cross section. In the current work, the H2CC(3B2) concentration was determined in an investigation of the photodissociation of vinyl chloride.

  2. EphB–ephrin-B2 interactions are required for thymus migration during organogenesis

    Science.gov (United States)

    Foster, Katie E.; Gordon, Julie; Cardenas, Kim; Veiga-Fernandes, Henrique; Makinen, Taija; Grigorieva, Elena; Wilkinson, David G.; Blackburn, C. Clare; Richie, Ellen; Manley, Nancy R.; Adams, Ralf H.; Kioussis, Dimitris; Coles, Mark C.

    2010-01-01

    Thymus organogenesis requires coordinated interactions of multiple cell types, including neural crest (NC) cells, to orchestrate the formation, separation, and subsequent migration of the developing thymus from the third pharyngeal pouch to the thoracic cavity. The molecular mechanisms driving these processes are unclear; however, NC-derived mesenchyme has been shown to play an important role. Here, we show that, in the absence of ephrin-B2 expression on thymic NC-derived mesenchyme, the thymus remains in the cervical area instead of migrating into the thoracic cavity. Analysis of individual NC-derived thymic mesenchymal cells shows that, in the absence of ephrin-B2, their motility is impaired as a result of defective EphB receptor signaling. This implies a NC-derived cell-specific role of EphB–ephrin-B2 interactions in the collective migration of the thymic rudiment during organogenesis. PMID:20616004

  3. Intrinsic fluorescence spectra characteristics of vitamin B1, B2, and B6

    Science.gov (United States)

    Yang, Hui; Xiao, Xue; Zhao, Xuesong; Hu, Lan; Lv, Caofang; Yin, Zhangkun

    2015-11-01

    This paper presents the intrinsic fluorescence characteristics of vitamin B1, B2 and B6 measured with 3D fluorescence Spectrophotometer. Three strong fluorescence areas of vitamin B2 locate at λex/λem=270/525nm, 370/525nm and 450/525nm, one fluorescence areas of vitamin B1 locates at λex/λem=370/460nm, two fluorescence areas of vitamin B6 locates at λex/λem=250/370nm and 325/370nm were found. The influence of pH of solution to the fluorescence profile was also discussed. Using the PARAFAC algorithm, 10 vitamin B1, B2 and B6 mixed solutions were successfully decomposed, and the emission profiles, excitation profiles, central wavelengths and the concentration of the three components were retrieved precisely through about 5 iteration times.

  4. Properties of a New Nonlinear Optical Crystal CdZn2B2O6

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fan; SHEN De-Zhong; SHEN Guang-Qiu; WANG Xiao-Qing

    2008-01-01

    @@ Cadmium dizinc diborate (CdZn2B2O6) single crystals have been grown for the first time. The crystal structure of CdZn2B2O6 is the same as that of the Cd3Zn3B4O12. The x-ray diffraction, infrated and Raman spectra,differential scanning calorimetry analysis and density indicate that the physical and chemical properties of both crystals are very similar. Especially, the nonlinear optical coefficients of CdZn2B2O6 and Cd3ZnaB4O12 crystals are 2.6 and 2.4 times as large as that of KH2PO4 crystal respectively. Chemical etching experiments indicated that these crystals are very stable in neutral solution and not hygroscopic in air at room temperature.

  5. Combustion Synthesis of TiC-TiB2-Based Cermets from Elemental Powders

    Directory of Open Access Journals (Sweden)

    Jun Yu

    2011-01-01

    Full Text Available TiC-TiB2-based cermets with Ni binder were fabricated using combustion synthesis assisted by pseudohot isostatic pressing by heating the compacted powder mixture to approximately 700°C. The effects of composition on microstructure and hardness of the synthesized samples were investigated. The samples exhibited finer microstructure and higher hardness as TiC/TiB2 volume ratio increased and as Ni increased up to 30 vol%. A relatively high hardness value of 1950 HV was obtained for TiC-TiB2-Ni(52.5/17.5/30 vol%. However, the transverse rupture strength and the modulus of elasticity values were not very high. This may be due to weak bonding strength of the interface between hard phases and Ni binder and/or insufficient densification of the samples.

  6. Plexin-B2 negatively regulates macrophage motility, Rac, and Cdc42 activation.

    Directory of Open Access Journals (Sweden)

    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.

  7. THE VITAMIN B(1) AND B(2) G CONTENT OF LIVER EXTRACT AND BREWERS' YEAST CONCENTRATE.

    Science.gov (United States)

    Miller, D K; Rhoads, C P

    1934-02-28

    1. Liver extract powder, No. 343 Lilly, and the same material prepared for parenteral use, when administered daily by mouth in amounts derived from 2.5 gm. of fresh whole liver, to rats weighing from 40 to 50 gm., contain sufficient vitamin B(1) to support normal growth, provided the animals receive in addition an adequate amount of vitamin B(2) G. Moreover, liver extract in the forms mentioned, administered in the same amounts, does not contain sufficient vitamin B(2) G to maintain normal growth of similar rate when all other necessary constituents of the diet are provided. 2. Liver extract (Lilly) in the form prepared for parenteral use, when administered daily by intraperitoneal injections, in amounts derived from 2.5 gm. of fresh whole liver, to rats under standard experimental conditions, does not contain sufficient vitamin B(2) G to maintain normal growth. Furthermore, the amount of vitamin B(1) present in liver extract in this form is not as effective in supporting normal growth when given by intraperitoneal injection as it is when given by mouth. 3. Vegex, when administered daily in amounts of 50, 150, and 250 mg. to rats of 40 to 50 gm. in weight contains sufficient vitamin B(1) to maintain normal growth of the rats, provided the animals receive in addition an adequate amount of vitamin B(2) G. However, vegex in the same amounts does not contain sufficient vitamin B(2) G to support normal growth of similar rats when all other necessary constituents of the diet are provided. 4. These experiments indicate that the extrinsic, anti-anemic factor of Castle and the thermostable growth-promoting food constituent, commonly known as vitamin B(2) G, are not identical.

  8. Effect of Er doping on the superconducting properties of porous MgB2

    Indian Academy of Sciences (India)

    O Erdem; E Yanmaz

    2015-02-01

    MgB2 bulk sample with porous structure was produced by using the in-situ solid-state reaction method under argon (Ar) atmosphere of 10 bar. Elemental Er in powder form was doped into MgB2 with different compositions (Mg1−Er)B2, where = 0.00, 0.03 and 0.05, in order to investigate the effect of rare-earth (RE) element Er on the structural and electromagnetic properties of porous MgB2. The Er-doped samples result in small grain size structure compared to the undoped one. The lattice constants and of the doped samples, determined from X-ray diffraction (XRD) analysis, increase with the increasing Er content, and consequently the superconducting transition temperature ($T^{\\text{onset}}_{c}$) of MgB2, determined from resistivity measurements, is slightly suppressed. Also, the upper critical field ($B_{c2}$), the irreversibility field ($B_{\\text{irr}}$) and the critical current density ($J_{c}$) values are significantly enhanced in the doped samples. For the best sample ( = 0.03), at 15 K under a magnetic field of 4 T, the $J_{c}$ value reaches 2.4×104 A cm-2, which is higher than that of the porous sample by an order of 103, and the $B_{\\text{irr}}$ value at 20 K reaches 9.7 T. These results imply that the RE element Er fills the pores, enhances the density and the grain connectivity. Hence, the superconducting properties of the porous MgB2 sample improve by Er doping.

  9. Theoretical study of the human bradykinin-bradykinin B2 receptor complex.

    Science.gov (United States)

    Gieldon, Artur; Lopez, Jakob J; Glaubitz, Clemens; Schwalbe, Harald

    2008-10-13

    The interaction of bradykinin (BK) with the bradykinin B2 receptor (B2R) was analyzed by using molecular modeling (MM) and molecular dynamics (MD) simulations. A homology model for B2R has been generated and the recently determined receptor-bound solid-state NMR spectroscopic structure of BK (Lopez et al., Angew. Chem. 2008, 120, 1692-1695; Angew. Chem. Int. Ed. 2008, 47, 1668-1671) has been modeled into the binding pocket of the receptor to probe the putative ligand-receptor interface. The experimental hormone structure fitted well into the binding pocket of the receptor model and remained stable during the MD simulation. We propose a parallel orientation of the side chains for Arg1 and Arg9 in BK that is bound to B2R. The MD simulation study also allows the conformational changes that lead to the activated form of B2R to be analyzed. The hydrogen bond between N140 (3.35) and W283 (6.48) is the key interaction that keeps the receptor in its inactive form. This hydrogen bond is broken during the MD simulation due to rotation of transmembrane helix 3 (TM3) and is replaced by a new hydrogen bond between W283 (6.48) and N324 (7.45). We propose that this interaction is specific for the activated form of the bradykinin B2 receptor. Additionally, we compared and discussed our putative model in the context of the structural model of the partially activated rhodopsin (Rh*) and with the known biochemical and structural data.

  10. User-Interface Design Characteristics of Fortune 500 B2C E-Commerce Sites and Industry Differences

    Science.gov (United States)

    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…

  11. B2C垂直搜索引擎的网络爬虫设计%Design of Web Crawlers for B2C Vertical Search Engines

    Institute of Scientific and Technical Information of China (English)

    杨亮; 刘利伟; 胡华莲

    2013-01-01

    A vertical search engine web crawler system based on Beautiful-Soup information extraction technique is developed. Experiment results indicate that the effective rate of information extraction is up to 95%and can meet commercial requirements.%  开发了基于 Beautiful-Soup 信息提取的 B2C 类垂直搜索引擎爬虫系统。测试结果表明:该爬虫的抓取有效率实际达到95%以上,满足商业应用的要求。

  12. B2C型电子商务产品的选择研究%Research on B2C eCommerce Product Selection

    Institute of Scientific and Technical Information of China (English)

    李振华; 王浣尘

    2002-01-01

    在认识电子商务的本质还是商务的基础上,以消费者的购买实现过程为参照系,构建了B2C型电子商务条件下产品综合评价指标体系,提出了应用模糊综合评价模型方法对其进行量化,并给出了量化的思路,为电子商务企业的产品经营选择提供理论和工程化支持.

  13. B2C电子商务服务质量评价研究%B2C E-Commerce Service Quality Assessment

    Institute of Scientific and Technical Information of China (English)

    史晓丹; 李波

    2014-01-01

    The study grades the service quality of the T-Mall, an online shopping platform, by calculating the index weight at various lev-els with the help of a mature B2C e-commerce service quality assessment system and AHP, Analytic Hierarchy Process. The overall ser-vice quality of the T-Mall is fairly good, in which the overall service level in terms of the service process is high, followed by that of service outcome. However, that of service remedy is low, even lower than the overall service quality of the T-Mall, which needs to be improved. The study could be used as a guide for businesses on T-Mall to promote service quality for better customer satisfaction and loyalty. It also offers reference frame and a basis for decision making in the assessment of domestic B2C e-commerce service quality.%通过借鉴成熟的B2C电子商务服务质量测评指标体系,采用层次分析法计算各级评价指标权重,以天猫为研究平台进行实证调研,进而得到对天猫的服务质量评价得分:天猫的总体服务质量处于较好水平,其中,服务过程指标的整体服务水平较高;而服务结果指标的整体服务水平次之,有待进一步提升;至于服务补救指标的整体服务水平较低,且低于天猫的整体服务质量,需要加强改进。微观上,该项研究可以指导天猫有针对性地提升企业服务质量,进一步提高顾客满意度和忠诚度;宏观上,该项研究为国内B2C电子商务企业服务质量评价提供了参考框架和决策依据,将有效促进国内电子商务行业服务质量的提升,推动电子商务行业的持续发展。

  14. 关于Diophantine方程2yny-x=(b+2)x-bx%On the Diophantine equation 2y ny-x =(b + 2) x-bx

    Institute of Scientific and Technical Information of China (English)

    关文吉; 车顺

    2014-01-01

    设b是大于3的正奇数.运用初等方法以及同余性质讨论了不定方程2yny-x=(b+2)x-bx的正整数解(x,y,n)的存在性问题,对于b(≠)7(mod8)的情况给出了该方程的全部解,从而部分地解决了该方程的可解性问题.

  15. Observation of the ηb(2S) Meson in Υ(2S)→γηb(2S), ηb(2S)→ hadrons and confirmation of the ηb(1S) meson.

    Science.gov (United States)

    Dobbs, S; Metreveli, Z; Tomaradze, A; Xiao, T; Seth, Kamal K

    2012-08-24

    The data for 9.3 million Υ(2S) and 20.9 million Υ(1S) taken with the CLEO III detector have been used to study the radiative population of states identified by their decay into 26 different exclusive hadronic final states. In the Υ(2S) decays, an enhancement is observed at a ~5σ level at a mass of 9974.6±2.3(stat)±2.1(syst) MeV. It is attributed to η(b)(2S) and corresponds to the Υ(2S) hyperfine splitting of 48.7±2.3(stat)±2.1(syst) MeV. In the Υ(1S) decays, the identification of η(b)(1S) is confirmed at a ~3σ level with M[η(b)(1S)] in agreement with its known value.

  16. Observation of interband pairing interaction in a two-band superconductor: MgB2.

    Science.gov (United States)

    Geerk, J; Schneider, R; Linker, G; Zaitsev, A G; Heid, R; Bohnen, K-P; v Löhneysen, H

    2005-06-10

    The recently discovered anisotropic superconductor MgB2 is the first of its kind showing the intriguing properties of two-band superconductivity. By tunneling experiments using thin film tunnel junctions, electron-coupled phonon spectra were determined showing that superconductivity in MgB2 is phonon mediated. In a further analysis, which involves first principles calculations, the strongest feature in these spectra could be traced back to the key quantity of two-band superconductivity, the interband pairing interaction. For the phonons, this interaction turns out quite selective. It involves mainly low-energy optical phonon modes, where the boron atoms move perpendicular to the boron planes.

  17. Isotope effect on electron-phonon interaction in the multiband superconductor MgB2

    Science.gov (United States)

    Mou, Daixiang; Manni, Soham; Taufour, Valentin; Wu, Yun; Huang, Lunan; Bud'ko, S. L.; Canfield, P. C.; Kaminski, Adam

    2016-04-01

    We investigate the effect of isotope substitution on the electron-phonon interaction in the multiband superconductor MgB2 using tunable laser-based angle-resolved photoemission spectroscopy. The kink structure around 70 meV in the σ band, which is caused by electron coupling to the E2 g phonon mode, is shifted to higher binding energy by ˜3.5 meV in Mg 10B2 and the shift is not affected by superconducting transition. These results serve as the benchmark for investigations of isotope effects in known, unconventional superconductors and newly discovered superconductors where the origin of pairing is unknown.

  18. Pair-breaking and superconducting state recovery dynamics in MgB2.

    Science.gov (United States)

    Demsar, J; Averitt, R D; Taylor, A J; Kabanov, V V; Kang, W N; Kim, H J; Choi, E M; Lee, S I

    2003-12-31

    We present studies of the photoexcited quasiparticle dynamics in MgB2 where, using femtosecond optical techniques, Cooper pair-breaking dynamics (PBD) have been temporally resolved for the first time. The PBD are strongly temperature and photoexcitation intensity dependent. Analysis of the PBD using the Rothwarf-Taylor equations suggests that the anomalous PBD arises from the fact that in MgB2 photoexcitation is initially followed by energy relaxation to high frequency phonons instead of, as commonly assumed, e-e thermalization. Furthermore, the bare quasiparticle recombination rate and the probability for pair breaking by phonons have been determined.

  19. How to successfully present a solution in a B2B sales meeting

    OpenAIRE

    Klemola, Mari

    2013-01-01

    This thesis contains research on presenting a solution in a B2B (business-to-business) sales meeting. This thesis is planned to complement the existing course material in the solution selling course at HAAGA-HELIA University of Applied Sciences’ Degree Programme in Sales. The objective of this thesis was to create a handbook to students about how to successfully present a solution in a B2B sales meeting. This is the main research question. The secondary research questions are: (1) how to ...

  20. Hardness Measurement of (TiB2-TiAl)/TiAl Symmetrically Function Gradient Materials

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    (TiB2-TiAl)/TiAl symmetrically function gradient materials (FGM) were prepared by spark plasma sintering (SPS). Owing to the difference of the thermal expansion coefficients between TiB2 and TiAl, a compressive surface stress was introduced to the FGM by the thermal expansion mismatch. The hardness values of the uniform materials and the FGM were tested, respectively. For the FGM with a compressive surface stress, hardness is obviously superior to that of the uniform material.When the FGM was subjected to heat treatment,the hardness decreased due to a partial relaxation of the compressive surface stress.

  1. China's B2C e-commerce development and its future prospects

    OpenAIRE

    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. ...

  2. Solution Fabrication of a Superconducting MgB2 Coated Conductor on Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    WANG Yin-Bo; CHEN Li-Ping; ZHANG Chen; WANG Yue; GUO Zheng-Shan; CHEN Yi-Ling; FENG Qing-Rong; GAN Zi-Zhao

    2012-01-01

    We report the solution fabrication of a MgB2 coated conductor on a stainless steel substrate. The precursor solution of Mg(BH4)2 diethyl ether is initially synthesized by refluxing the milled mixture of NaBH4 and MgCl2 in diethyl ether. Then the Mg(BH4)2 diethyl ether is spin coated on a stainless steel substrate and annealed in Mg vapor, which yields a homogeneous MgB2 coated conductor. X-ray diffraction indicates that the grown MgB2 coated conductor is polycrystalline. It has a superconducting transition temperature of 34-37K. The slope of the upper critical field Hc2 increases with decreasing temperature, and the extrapolated value of Hc2 (0) reaches ~28T. The critical current density estimated by the Bean model is Jc (25K, 0T)~106 A·cm-2. These parameters indicate that the solution method is potentially able to produce MgB2 coated conductors that can satisfy application purposes.%We report the solution fabrication of a MgB2 coated conductor on a stainless steel substrate.The precursor solution of Mg(BH4 )2 diethyl ether is initially synthesized by refluxing the milled mixture of NaBH4 and MgCl2 in diethyl ether.Then the Mg(BH4)2 diethyl ether is spin coated on a stainless steel substrate and annealed in Mg vapor,which yields a homogeneous MgB2 coated conductor.X-ray diffraction indicates that the grown MgB2 coated conductor is polycrystalline.It has a superconducting transition temperature of 34-37K.The slope of the upper critical field HC2 increases with decreasing temperature,and the extrapolated value of Hc2 (0)reaches ~28 T.The critical current density estimated by the Bean model is JC (25K,0 T)~1 06 A.cm-2.These parameters indicate that the solution method is potentially able to produce MgB2 coated conductors that can satisfy application purposes.

  3. Microstructure and properties of in situ A356/TiB2 composite

    Institute of Scientific and Technical Information of China (English)

    LE Yong-kang; CHEN Dong; MA Nai-heng; ZHANG Wen-jing; MAO Jian-wei; WANG Hao-wei

    2006-01-01

    In situ A356/TiB2 composites were successfully fabricated via in-melt reaction among aluminium alloy, K2TiF6 and KBF4 compounds. The composite was examined by using XRD, SEM and EDX techniques. The experimental results reveal that TiB2 are dispersed homogeneously into the aluminium alloy matrix. The mechanical properties of the composites increase significantly with the addition of reinforcement, and the tensile fractography of the composite exhibits to be ductile though the elongation of the composites decreases compared with the unreinforced matrix alloy.

  4. Trends in dislocation core structures and mechanical behavior in B2 aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Vailhe, C.; Farkas, D. [Virginia Polytechnic Inst., Blacksburg, VA (United States). Dept. of Materials Science and Engineering

    1995-08-01

    In an effort to understand the deformation mechanism in high temperature B2 intermetallics, atomistic simulations were carried out for dislocation cores in a series of compounds exhibiting the B2 structure (FeAl, NiAl, CoAl). A comparison was made on the basis of core structures, dislocation splittings and Peierls stress values. The (110) and (112) {gamma} surfaces were computed for these three compounds. The importance of the APB values and the maximum shear faults for explaining the dislocation behavior is discussed.

  5. Gliosis after traumatic brain injury in conditional ephrinB2-knockout mice

    Institute of Scientific and Technical Information of China (English)

    LIU Ling; CHEN Xiao-lin; YANG Jian-kai; REN Ze-guang; WANG Shuo

    2012-01-01

    Background In response to the injury of the central nervous system (CNS),the astrocytes upregulate the expression of glial fibrillary acidic protein (GFAP),which largely contributes to the reactive gliosis after brain injury.The regulatory mechanism of this process is still not clear.In this study,we aimed to compare the ephrin-B2 deficient mice with the wild type ones with regard to gliosis after traumatic brain injury.Methods We generated ephrin-B2 knockout mice specifically in CNS astrocytes.Twelve mice from this gene-knockout strain were randomly selected along with twelve mice from the wild type littermates.In both groups,a modified controlled cortical impact injury model was applied to create a closed traumatic brain injury.Twenty-eight days after the injury,Nissl staining and GFAP immunofluorescence staining were used to compare the brain atrophy and GFAP immunoreactivity between the two groups.All the data were analyzed by t-test for between-group comparison.Results We successfully set up the conditional ephrin-B2 knockout mice strain,which was confirmed by genotyping and ephrin-B2/GFAP double staining.These mice developed normally without apparent abnormality in general appearance.Twenty-eight days following brain injury,histopathology revealed by immunohistochemistry showed different degrees of cerebral injuries in both groups.Compared with wild-type group,the ephrin-B2 knockout group exhibited less brain atrophy ratio for the injured hemispheres (P=0.005) and hippocampus (P=0.027).Also the wild-type group demonstrated greater GFAP immunoreactivity increment within hippocampal regions (P=0.008).Conclusions The establishment of conditional ephrin-B2 knockout mice provides us with a new way to explore the role of ephrin-B2 in astrocytes.Our findings revealed less atrophy and GFAP immunoreactivity in the knockout mice strain after traumatic brain injury,which implied ephrin-B2 could be one of the promoters to upregulate gliosis following brain injury.

  6. Preparation and Characterization of the New Superconductor MgB2

    Institute of Scientific and Technical Information of China (English)

    SUN Yu-Ping; ZHAO Zhong-Xian; SONG Wen-Hai; DAI Jian-Ming; WU Xing-Cai; WANG Kai-You; ZHAO Bing; XIAO Hong; DU Jia-Ju; WEN Hai-Hu

    2001-01-01

    Polycrystalline samples of the new superconductor MgB2 are prepared by a solid-state reaction using Mg and Bpowders. The resistance measurement shows that the onset transition temperature and zero resistance transitiontemperature are Tonsetc = 43.8 K and Tc0 = 37 K, respectively. The Tco strongly depends on measuring current. The diamagnetic transition temperature of ~38 K is obtained by the ac susceptibility measurement. X-ray powderdiffraction spectra of MgB2 can be indexed using hexagonal structure with space group P6/mmm and latticeparameters a = 0.30864 and c = 0.35212 nm. A second phase, probably MgO, is also found.

  7. Short syntheses of enantiopure calystegine B-2, B-3, and B-4

    DEFF Research Database (Denmark)

    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....

  8. A New Evolution Mechanism Model for B2B E-Commerce Network

    OpenAIRE

    Zhihong Tian; Zhenji Zhang; Xiaolan Guan

    2013-01-01

    To study the structure and evolution mechanism of B2B e-commerce network, the authors propose a network with several layers description of B2B e-commerce market. The empirical analysis from Alibaba.com shows that degree distribution of the network structure follows power-law. Based on modified BA (Barabasi-Albert) model, a new model is proposed, adding layers, fitness parameters, and more reasonable growth mechanism. The model reveals that, the structure of the network is stable, and the aver...

  9. Spectroscopic evidence against Rh 4d itinerant ferromagnetism in CeRh3B2

    Science.gov (United States)

    Sampathkumaran, E. V.; Kaindl, G.; Laubschat, C.; Krone, W.; Wortmann, G.

    1985-03-01

    Valence-band photoemission and IIII-edge x-ray absorption studies were performed on RRh3B2 (R = La, Ce, and Pr) compounds in order to explore the origin of the anomalously high magnetic ordering temperature of CeRh3B2. From the low density of Rh 4d states at EF and the approximate trivalency of Ce, itinerant magnetism in the Rh 4d band can be excluded. Instead, the magnetism is proposed to originate from Ce moments, enhanced by 4f hybridization with Rh d orbitals.

  10. Competence Neworks: Effects on Corporate Branding in B2B SMEs

    OpenAIRE

    2015-01-01

    The purpose of this thesis is to investigate the effects of competence networks on corporate branding in B2B SMEs and to develop a conceptual model of these effects. After reviewing the relevant literature that explores the field, eight components of corporate branding in an effective growth stage of an SME have been identified. Founders Alliance is a competence network in Sweden that was chosen as a case for our study. Representatives of five B2B SMEs within Founders Alliance were interviewe...

  11. MgB2 ultrathin films fabricated by hybrid physical chemical vapor deposition and ion milling

    Directory of Open Access Journals (Sweden)

    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.

  12. Modelling the B2C Marketplace: Evaluation of a Reputation Metric for e-Commerce

    Science.gov (United States)

    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.

  13. MgB2 ultrathin films fabricated by hybrid physical chemical vapor deposition and ion milling

    Science.gov (United States)

    Acharya, Narendra; Wolak, Matthäus A.; Tan, Teng; Lee, Namhoon; Lang, Andrew C.; Taheri, Mitra; Cunnane, Dan; Karasik, Boris. S.; Xi, X. X.

    2016-08-01

    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.

  14. An Inter-enterprise Workflow Model for Supply Chain and B2B E-commerce

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The goals of B2B electronic commerce and supply chain management system are to implement interoperability of independent enterprises, to smooth the information flow between them and to deploy business processes over multiple enterprises. The inherent characteristics of workflow system make it suitable to implement the cross organization management. This paper, firstly, proposes an inter-enterprises workflow model based on the agreement to support the construction of supply chain management system and B2B electronic commerce. This model has extended the standard workflow model. After that, an architecture which supports the model has been introduced, especially it details the structure and implementation of interfaces between enterprises.

  15. Elastic Constants of Superconducting MgB2 from Molecular Dynamics Simulations with Shell Model

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The elastic constants of superconducting MgB2 are calculated using a molecular dynamics method (MD)with shell model. The lattice parameters, five independent elastic constants, equations of state (EOS), Debye temperature, and bulk modulus of MgB2 are obtained. Meanwhile, the dependence of the bulk modulus B, the lattice parameters a and c, and the unit cell volume V on the applied pressure are presented. It is demonstrated that the method introduced here can well reproduce the experimental results with a reasonable accuracy.

  16. Efficient 266 nm Ultraviolet Beam Generation in K2Al2B2O7 Crystal

    Institute of Scientific and Technical Information of China (English)

    吕军华; 王桂玲; 许祖彦; 陈创天; 王继扬; 张承乾; 刘耀岗

    2002-01-01

    The ultraviolet beam at 266 nm was obtained by fourth harmonic generation of 1064 nm Nd:YAG laser radiation through a nonlinear crystal K2Al2 B2O7 (KABO). The fundamental frequency of a Hash-lamp pumped Nd: YAG laser was doubled in a β-Ba2B2O4 crystal to generate a second harmonic output at the wavelength of 532 nm,and then doubled again in the KABO crystal to generate the fourth harmonic output at 266 nm. The optical conversion efficiency from 532 to 266 nm was investigated for the first time, and 13% was achieved.

  17. Low-Temperature Synthesis of Superconducting Nanocrystalline MgB2

    Directory of Open Access Journals (Sweden)

    Jun Lu

    2010-01-01

    Full Text Available Magnesium diboride (MgB2 is considered a promising material for practical application in superconducting devices, with a transition temperature near 40 K. In the present paper, nanocrystalline MgB2 with an average particle size of approximately 70 nm is synthesized by reacting LiBH4 with MgH2 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.

  18. MEANS FOR COOLING REACTORS

    Science.gov (United States)

    Wheeler, J.A.

    1957-11-01

    A design of a reactor is presented in which the fuel elements may be immersed in a liquid coolant when desired without the necessity of removing them from the reactor structure. The fuel elements, containing the fissionable material are in plate form and are disposed within spaced slots in a moderator material, such as graphite to form the core. Adjacent the core is a tank containing the liquid coolant. The fuel elements are mounted in spaced relationship on a rotatable shaft which is located between the core and the tank so that by rotation of the shaft the fuel elements may be either inserted in the slots in the core to sustain a chain reaction or immersed in the coolant.

  19. Compact fusion reactors

    CERN Document Server

    CERN. Geneva

    2015-01-01

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

  20. Reactor Neutrino Spectra

    OpenAIRE

    Hayes, A. C.; Vogel, Petr

    2016-01-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these spectra and their associated uncertainties is crucial for neutrino oscillation studies. The spectra used to date have been determined either by converting measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that make up the spectra, using modern databases as input. The uncertainties in the subdominant corrections to β-decay plague both methods, and we ...

  1. REACTOR MODERATOR STRUCTURE

    Science.gov (United States)

    Greenstreet, B.L.

    1963-12-31

    A system for maintaining the alignment of moderator block structures in reactors is presented. Integral restraining grids are placed between each layer of blocks in the moderator structure, at the top of the uppermost layer, and at the bottom of the lowermost layer. Slots are provided in the top and bottom surfaces of the moderator blocks so as to provide a keying action with the grids. The grids are maintained in alignment by vertical guiding members disposed about their peripheries. (AEC)

  2. BOILER-SUPERHEATED REACTOR

    Science.gov (United States)

    Heckman, T.P.

    1961-05-01

    A nuclear power reactor of the type in which a liquid moderator-coolant is transformed by nuclear heating into a vapor that may be used to drive a turbo- generator is described. The core of this reactor comprises a plurality of freely suspended tubular fuel elements, called fuel element trains, within which nonboiling pressurized liquid moderator-coolant is preheated and sprayed through orifices in the walls of the trains against the outer walls thereof to be converted into vapor. Passage of the vapor ovcr other unwetted portions of the outside of the fuel elements causes the steam to be superheated. The moderatorcoolant within the fuel elements remains in the liqUid state, and that between the fuel elements remains substantiaily in the vapor state. A unique liquid neutron-absorber control system is used. Advantages expected from the reactor design include reduced fuel element failure, increased stability of operation, direct response to power demand, and circulation of a minimum amount of liquid moderatorcoolant. (A.G.W.)

  3. Multiscale Modeling of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2: Application to Lattice Thermal Conductivity

    Science.gov (United States)

    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.

  4. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  5. Emericella astellata, a new producer of aflatoxin B-1, B-2 and sterigmatocystin

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Samson, R.A.; Smedsgaard, Jørn

    2004-01-01

    To report on aflatoxin B-1 and B-2 production from a species of Emericella. Methods and Results: Aflatoxins and sterigmatocystin were determined by high-pressure liquid chromatography (HPLC) with diode array detection and confirmed by HPLC with mass spectrometry detection. Among 30 known species ...

  6. 26 CFR 1.643(b)-2 - Dividends allocated to corpus.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Dividends allocated to corpus. 1.643(b)-2... to corpus. Extraordinary dividends or taxable stock dividends which the fiduciary, acting in good faith, determines to be allocable to corpus under the terms of the governing instrument and...

  7. Point pinning centers in SiC doped MgB2 wires after HIP

    Science.gov (United States)

    Gajda, D.; Zaleski, A.; Morawski, A.; Cetner, T.; Thong, C. J.; Rindfleisch, M. A.

    2016-08-01

    In this study we show that dominant point pinning mechanisms in SiC doped MgB2 wires can be obtained by annealing in high isostatic pressure. The results indicate that the point pinning centers increase the critical current density in medium and high magnetic fields, but not at low magnetic fields. In addition, our study shows that dominant pinning mechanism changes from point to surface type with increase of magnetic fields. An MgB2 wire heat treated in a high pressure of 1.4 GPa shows a high critical current density of 100 A mm-2 in 13 T at 4.2 K. Scanning electron microscope studies show that high isostatic pressure increases the density of the MgB2 material, eliminates voids, allows for small Si precipitates and homogeneous distribution of Si precipitates. Transport measurements E - B and E - I show that the MgB2 wires manufactured by Hyper Tech Research did not heat up after transition into a normal state. This is important for applications in coils.

  8. The origin of multiple superconducting gaps in MgB2.

    Science.gov (United States)

    Souma, S; Machida, Y; Sato, T; Takahashi, T; Matsui, H; Wang, S-C; Ding, H; Kaminski, A; Campuzano, J C; Sasaki, S; Kadowaki, K

    2003-05-01

    Magnesium diboride, MgB2, has the highest transition temperature (T(c) = 39 K) of the known metallic superconductors. Whether the anomalously high T(c) can be described within the conventional BCS (Bardeen-Cooper-Schrieffer) framework has been debated. The key to understanding superconductivity lies with the 'superconducting energy gap' associated with the formation of the superconducting pairs. Recently, the existence of two kinds of superconducting gaps in MgB2 has been suggested by several experiments; this is in contrast to both conventional and high-T(c) superconductors. A clear demonstration of two gaps has not yet been made because the previous experiments lacked the ability to resolve the momentum of the superconducting electrons. Here we report direct experimental evidence for the two-band superconductivity in MgB2, by separately observing the superconducting gaps of the sigma and pi bands (as well as a surface band). The gaps have distinctly different sizes, which unambiguously establishes MgB2 as a two-gap superconductor.

  9. Thickness dependence of Jc (0) in MgB2 films

    Science.gov (United States)

    Chen, Yiling; Yang, Can; Jia, Chunyan; Feng, Qingrong; Gan, Zizhao

    2016-06-01

    MgB2 superconducting films, whose thicknesses range from 10 nm to 8 μm, have been fabricated on SiC substrates by hybrid physical-chemical vapor deposition (HPCVD) method. It is the first time that the Tc and the Jc of MgB2 films are studied on such a large scale. It is found that with the increasing of thickness, Tc elevates first and then keeps roughly stable except for some slight fluctuations, while Jc (5 K, 0 T) experiences a sharp increase followed by a relatively slow fall. The maximum Jc (5 K, 0 T) = 2.3 × 108 A cm-2 is obtained for 100 nm films, which is the experimental evidence for preparing high-quality MgB2 films by HPCVD method. Thus, this work may provide guidance on choosing the suitable thickness for applications. Meanwhile, the films prepared by us cover ultrathin films, thin films and thick films, so the study on them will bring a comprehensive understanding of MgB2 films.

  10. Single-mode biological distributed feedback lasers based on vitamin B2 doped gelatin

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Maier-Flaig, F.; Lemmer, U.

    Biological second-order distributed feedback (DFB) lasers are presented. Riboflavin (vitamin B2) doped gelatin as active material is spin-coated onto nanoimprinted polymer with low refractive index. DFB grating periods of 368 nm and 384 nm yield laser emission at 543 nm and 562 nm, respectively....

  11. Solid-liquid interface free energies of pure bcc metals and B2 phases.

    Science.gov (United States)

    Wilson, S R; Gunawardana, K G S H; Mendelev, M I

    2015-04-07

    The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: Pm3̄m; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic "Na" potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observed in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of "Na" potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Moreover, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.

  12. Dynamical Trust and Reputation Computation Model for B2C E-Commerce

    Directory of Open Access Journals (Sweden)

    Bo Tian

    2015-10-01

    Full Text Available Trust is one of the most important factors that influence the successful application of network service environments, such as e-commerce, wireless sensor networks, and online social networks. Computation models associated with trust and reputation have been paid special attention in both computer societies and service science in recent years. In this paper, a dynamical computation model of reputation for B2C e-commerce is proposed. Firstly, conceptions associated with trust and reputation are introduced, and the mathematical formula of trust for B2C e-commerce is given. Then a dynamical computation model of reputation is further proposed based on the conception of trust and the relationship between trust and reputation. In the proposed model, classical varying processes of reputation of B2C e-commerce are discussed. Furthermore, the iterative trust and reputation computation models are formulated via a set of difference equations based on the closed-loop feedback mechanism. Finally, a group of numerical simulation experiments are performed to illustrate the proposed model of trust and reputation. Experimental results show that the proposed model is effective in simulating the dynamical processes of trust and reputation for B2C e-commerce.

  13. Rational design of MgB2 conductors toward practical applications

    Science.gov (United States)

    Patel, Dipak; Hossain, Md Shahriar Al; Motaman, Ashkan; Barua, Shaon; Shahabuddin, Mohammed; Kim, Jung Ho

    2014-09-01

    We report the research progress that has been made on developing rational MgB2 superconducting conductors toward practical applications. Owing to the poor performance of the critical current density (Jc) of bare MgB2, various techniques have been developed to overcome this obstacle. Among these, chemical doping has proved to be the most effective way to enhance the superconducting properties, such as Jc and the irreversibility field (Birr). More than a hundred different forms of dopants have been investigated over the past 13 years. Among these, the most effective dopants have been identified to be silicon carbide, carbon, and malic acid. The best results, Birr of 22 T and Jc of 40,000 A cm-2 at 4.2 K and 10 T, have been reported for malic acid treated MgB2 conductors, which have matched the benchmark performance of commercial low temperature superconductor wire such as Nb-Ti. This work will review and discuss the progress on MgB2 conductor development over the past few years at the University of Wollongong and Hyper Tech Research, Inc.

  14. Tricationic metastability by symmetry restrictions: B2 n+, n = 3,4

    Science.gov (United States)

    Hogreve, H.

    2017-01-01

    To explain the experimentally observed metastability of the trication B2 3+, we study this system by various ab-initio methods. Whereas the electronic ground state X2Σu + of B2 3+ turns out to be unstable, the potential energy curves of the lowest excited state 12Πu and of the quartet state 14Σg - form barriers that support quasi-bound vibronic states. The lifetimes of these states are not only determined by the respective (dissociative) tunnelling rates, but also by possible radiative electronic transitions and predissociation via spin-orbit coupling, where the latter furnish the decisive decay mechanism for the low-lying vibronic levels. In case of the quadruply charged system B2 4+, our computations do not predict any metastable states in the low-lying electronic spectrum. The deviation from a purely Coulombic repulsive behaviour in B2 4+ is quantified by fitting the potential energy curves to a modified Murrell-Sorbie function.

  15. The first structure of a bacterial diterpene cyclase: CotB2.

    Science.gov (United States)

    Janke, Ronja; Görner, Christian; Hirte, Max; Brück, Thomas; Loll, Bernhard

    2014-06-01

    Sesquiterpenes and diterpenes are a diverse class of secondary metabolites that are predominantly derived from plants and some prokaryotes. The properties of these natural products encompass antitumor, antibiotic and even insecticidal activities. Therefore, they are interesting commercial targets for the chemical and pharmaceutical industries. Owing to their structural complexity, these compounds are more efficiently accessed by metabolic engineering of microbial systems than by chemical synthesis. This work presents the first crystal structure of a bacterial diterpene cyclase, CotB2 from the soil bacterium Streptomyces melanosporofaciens, at 1.64 Å resolution. CotB2 is a diterpene cyclase that catalyzes the cyclization of the linear geranylgeranyl diphosphate to the tricyclic cyclooctat-9-en-7-ol. The subsequent oxidation of cyclooctat-9-en-7-ol by two cytochrome P450 monooxygenases leads to bioactive cyclooctatin. Plasticity residues that decorate the active site of CotB2 have been mutated, resulting in alternative monocyclic, dicyclic and tricyclic compounds that show bioactivity. These new compounds shed new light on diterpene cyclase reaction mechanisms. Furthermore, the product of mutant CotB2(W288G) produced the new antibiotic compound (1R,3E,7E,11S,12S)-3,7,18-dolabellatriene, which acts specifically against multidrug-resistant Staphylococcus aureus. This opens a sustainable route for the industrial-scale production of this bioactive compound.

  16. Deletion of Kinin B2 Receptor Alters Muscle Metabolism and Exercise Performance.

    Directory of Open Access Journals (Sweden)

    Felipe C G Reis

    Full Text Available Metabolic syndrome is a cluster of metabolic risk factors such as obesity, diabetes and cardiovascular diseases. Mitochondria is the main site of ATP production and its dysfunction leads to decreased oxidative phosphorylation, resulting in lipid accumulation and insulin resistance. Our group has demonstrated that kinins can modulate glucose and lipid metabolism as well as skeletal muscle mass. By using B2 receptor knockout mice (B2R-/- we investigated whether kinin action affects weight gain and physical performance of the animals. Our results show that B2R-/- mice are resistant to high fat diet-induced obesity, have higher glucose tolerance as well as increased mitochondrial mass. These features are accompanied by higher energy expenditure and a lower feed efficiency associated with an increase in the proportion of type I fibers and intermediary fibers characterized by higher mitochondrial content and increased expression of genes related to oxidative metabolism. Additionally, the increased percentage of oxidative skeletal muscle fibers and mitochondrial apparatus in B2R-/- mice is coupled with a higher aerobic exercise performance. Taken together, our data give support to the involvement of kinins in skeletal muscle fiber type distribution and muscle metabolism, which ultimately protects against fat-induced obesity and improves aerobic exercise performance.

  17. The High-Pressure Phase of MgB2C2

    NARCIS (Netherlands)

    Woerle, Michael; Fischbach, Urs; Widmer, Daniel; Krumeich, Frank; Nesper, Reinhard; Evers, Juergen; Stalder, Roland; Ulmer, Peter

    2010-01-01

    A high-pressure modification of MgB2C2 was synthesized and structurally characterized. The compound crystallizes in the orthorhombic space group Pnnm, with the lattice parameters a = 7.19633(3) angstrom, b = 4.61791(13) angstrom and c = 2.77714(8) angstrom. The compound contains heterographene B-C n

  18. Designing the marketing-sales interface in B2B firms

    NARCIS (Netherlands)

    Biemans, W.G.; Makovec Brencic, M.

    2007-01-01

    Purpose - This paper explores the marketing-sales interface in Dutch and Slovenian B2B firms. Design/methodology/approach - The study included 11 Dutch firms and ten Slovenian firms, with both samples as closely matched as possible. The firms were all manufacturers of physical products that operate

  19. Data of evolutionary structure change: 1CF5B-2JJRA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CF5B-2JJRA 1CF5 2JJR B A DVNFDLSTATAKTYTKFIEDFRATLPFSHKVYDIPLLYS...ID> A 2JJRA SYFFNEASATE LEU CA 336 2JJR A 2JJRA...Chain> 2JJR A 2JJRA...bChain>A 2JJRA GKVTS-DIALL

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

    DEFF Research Database (Denmark)

    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...

  1. Hysteresis in the field-induced magnetic structure in TmNi2B2C

    DEFF Research Database (Denmark)

    Eskildsen, M.R.; Harada, K.; Gammel, P.L:

    1999-01-01

    Using small-angle neutron scattering we have studied the flux line lattice and the magnetic structure in TmNi2B2C. With an applied field parallel to the crystalline c-axis several magnetic and flux line lattice symmetry transitions have been reported. The subject of this paper is the held-induced...

  2. CertiLingua programm: 2 x B2 + LAK + … / Tõnu Tender

    Index Scriptorium Estoniae

    Tender, Tõnu, 1965-

    2015-01-01

    CertiLingua (sertifikaat + keel) on Euroopa kvaliteeditunnistus, mis tõendab õppeasutuse lõpetaja kahe võõrkeele oskust B2-keeletasemel, Euroopa pädevusi ja kultuuridevahelisi (rahvusvahelisi) kogemusi. Seda sertifikaati väljastavad CL programmiga liitunud riikide piirkondade õppeasutused, mis on esitanud oma haridusministeeriumile taotluse ning saanud akrediteeringu

  3. Potential of MgB2 superconductors in direct drive generators for wind turbines

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Liu, Dong; Magnusson, Niklas

    2015-01-01

    by using the current cost of 4 €/m for the MgB2 wire from Columbus Superconductors and also a possible future cost of 1 €/m if a superconducting offshore wind power capacity of 10 GW has been introduced by 2030 as suggested in a roadmap. The obtained topologies are compared to what is expected from...

  4. Microstructural and superconducting properties of C6H6 added bulk MgB2 superconductor

    Science.gov (United States)

    Babaoğlu, Meral G.; Safran, Serap; Çiçek, Özlem; Ağıl, Hasan; Ertekin, Ercan; Hossain, Md. Shahriar A.; Yanmaz, Ekrem; Gencer, Ali

    2012-10-01

    The effect of aromatic hydrocarbon (benzene, C6H6) addition on lattice parameters, microstructure, critical temperature (Tc), critical current density (Jc) of bulk MgB2 has been studied. In this work only 2 mol% C6H6 addition was found to be very effective in increasing the Jc values, while resulting in slight reduction of the Tc. Jc values of 2 mol% C6H6 added MgB2 bulks reached to 1.83×106 A/cm2 at 15 K and 0 T. Microstructural analyses suggest that Jc enhancement is associated with the substitution of carbon with boron and which also results in the smaller MgB2 grain size. The change in the lattice parameters or the lattice disorder is claimed as a cause of the slight reduction in the Tc by carbon addition. We note that our results show the advantages of C6H6 addition include homogeneous mixing of precursor powders, avoidance of expansive nanoadditives, production of highly reactive C, and significant enhancement in Jc of MgB2, compared to un-doped samples.

  5. Nustar detection of the blazar B2 1023+25 at redshift 5.3

    DEFF Research Database (Denmark)

    Sbarrato, T.; Tagliaferri, G.; Ghisellini, G.

    2013-01-01

    B2 1023+25 is an extremely radio-loud quasar at z = 5.3 that was first identified as a likely high-redshift blazar candidate in the SDSS+FIRST quasar catalog. Here, we use the Nuclear Spectroscopic Telescope Array (NuSTAR) to investigate its non-thermal jet emission, whose high-energy component w...

  6. Production of fumonisins B2 and B4 in Tolypocladium species

    DEFF Research Database (Denmark)

    Mogensen, Jesper Mølgaard; Møller, Kirsten Amalie; von Freiesleben, Pernille;

    2011-01-01

    Tolypocladium inflatum is known primarily for its production of the cyclosporines that are used as an immunosuppressive drug. However, we report here the production of the carcinogenic fumonisins B2 and B4 by this biotechnologically relevant fungal genus. These mycotoxins were detected in 11 stra...

  7. Phase diagram of the B-B2O3 system at pressures to 24 GPa

    OpenAIRE

    Turkevich, Vladimir Z.; Turkevich, Dmitry V.; Solozhenko, Vladimir L.

    2016-01-01

    The evolution of topology of the B-B2O3 phase diagram has been studied at pressures up to 24 GPa using models of phenomenological thermodynamics with interaction parameters derived from experimental data on phase equilibria at high pressures and high temperatures.

  8. High-performance dense MgB2 superconducting wire fabricated from mechanically milled powder

    Science.gov (United States)

    Kodama, Motomune; Suzuki, Takaaki; Tanaka, Hideki; Okishiro, Kenji; Okamoto, Kazutaka; Nishijima, Gen; Matsumoto, Akiyoshi; Yamamoto, Akiyasu; Shimoyama, Jun-ichi; Kishio, Kohji

    2017-04-01

    Owing to the relatively high critical temperature and the low manufacturing cost, MgB2 superconducting wires are promising for liquid helium-free superconducting applications. Today, commercially available MgB2 wires are manufactured by either an in situ or ex situ powder-in-tube process, the in situ process being more effective to obtain high critical current density. In in situ-processed wires, however, the critical current density is seriously suppressed by the high porosity of MgB2 filaments. To resolve this problem, we propose an innovative method of using precursor powder prepared by mechanical milling of magnesium, boron, and coronene powders. This precursor powder has a metal–matrix–composite structure, in which boron particles are dispersed in a magnesium matrix. The plastic deformation of the precursor powder through wire processing leads to compact packing, and a dense MgB2 filament is generated after heat treatment. As a result, the limitation of critical current density that occurs for the typical in situ process is overcome, and the practical critical current density of 103 A mm‑2 is obtained at 10 K and 6.1 T, at 15 K and 4.8 T, and at 20 K and 3.3 T.

  9. Planning LIS Doctoral Education around a Focused Theme: A Report on the B2A Program

    Science.gov (United States)

    Bennett-Kapusniak, Renee; McCleer, Adriana; Glover, Jeannette; Thiele, Jennifer; Wolfram, Dietmar

    2016-01-01

    This report discusses the Overcoming Barriers to Information Access (B2A) program. This is a doctoral cohort program at the University of Wisconsin-Milwaukee funded by the Institute for Museum and Library Services. The program has focused on educating the next generation of doctoral graduates in library and information science with an emphasis on…

  10. On the study of phase formation and critical current density in superconducting MgB2

    Indian Academy of Sciences (India)

    Suchitra Rajput; Sujeet Chaudhary; Subhash C Kashyap; Pankaj Srivastava

    2006-06-01

    Superconducting bulk MgB2 samples have been synthesized by employing sintering technique without using any additional process steps, generally undertaken in view of the substantial loss of magnesium, during heat treatment. Starting with Mg rich powders having different atomic ratios of Mg : B, as against the nominally required Mg : B = 1 : 2 ratio, we have obtained superconducting MgB2 samples of different characteristics. The effect of excess Mg in the starting mixture and processing temperature on the phase-formation, transition temperature (C) and critical current density (C) have been investigated by electrical transport and a.c. susceptibility measurements. The X-ray diffraction and X-ray photoelectron spectroscopic analyses of MgB2 bulk samples have been carried out to understand the role of excess Mg and the effect of processing temperature. It is established that MgB2 samples with high critical current density can be synthesized from a Mg rich powder having Mg : B in 2 : 2 ratio, at temperatures around 790°C. Critical current density has been found to vary systematically with processing temperature.

  11. Data of evolutionary structure change: 1N28B-2NOTA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1N28B-2NOTA 1N28 2NOT B A ALVNFHRMIKLTTG--KEAALSYGFYGCHCGVGGRGSPK.../pdbChain> 2NOTA GPYCRNIKKKC EEE HH -17.02199935913086 tion> 0.8999999761581...1 -0.6779999732971191 0.125 0.7770000100135803 -0.6169999837875366 tio...> 1 2NOT A 2NOTA

  12. erbB2 Overexpression in Uterine Serous Cancer: A Molecular Target for Trastuzumab Therapy

    Directory of Open Access Journals (Sweden)

    Karim S. ElSahwi

    2011-01-01

    Full Text Available Endometrial cancer is the most common female genital tract malignancy in the United States. Type I endometrial cancer is usually diagnosed at an early stage, and has a good prognosis. Type II is very aggressive, and is responsible for most uterine cancer relapses and deaths. Uterine serous adenocarcinomas (USC constitute the majority of Type II variants. They have a higher propensity for lymph node and distant metastases. They are frequently aneuploid and associated with p53 mutations. erbB2 overexpression in USC has been described. The incidence, which is higher in African Americans, ranges from 18–80%. erbB2 overexpression was found to be associated with higher stage, chemoresistance, and worse survival. Trastuzumab a humanized mAb was approved by the FDA for treatment of breast cancers that overexpress erbB2 in combination with standard chemotherapy. Evidence of trastuzumab activity in USC has been reported in vitro, as well as in case reports of advanced and recurrent cases. Promising results were obtained in these heavily pretreated patients either with trastuzumab alone or in combination with chemotherapy. This supports the hypothesis that trastuzumab may very well be an attractive and viable treatment option for advanced stage USC tumors that overexpress the erbB2, and is worthy of further study.

  13. Magnetism and superconductivity in the system Ce1-xLaxRh3B2

    Science.gov (United States)

    Malik, S. K.; Umarji, A. M.; Shenoy, G. K.; Aldred, A. T.; Niarchos, D. G.

    1985-10-01

    The compound CeRh3B2 is magnetically ordered with a low saturation moment of ~0.4 μB per formula unit and an unusually large Curie temperature of 115 K while isostructural LaRh3B2 is superconducting with a transition temperature of ~2.3 K. Magnetic and superconducting studies on the series of compounds Ce1-xLaxRh3B2 reveal that the magnetic state persists for 0<=x<=0.8. The magnetic moment per Ce ion goes through a maximum and the Curie temperature decreases as La is substituted for Ce. On the La-rich side, superconductivity is destroyed even with 1% replacement of La by Ce, indicating a strong coupling of Ce 4f moments with conduction-electron spins. The temperature dependence of the upper critical field of LaRh3B2 has been measured and is discussed in terms of Werthammer-Helfand-Hohenberg theory.

  14. Measurement of local moment on Ce in CeRh3B2

    Science.gov (United States)

    Devare, S. H.; Devare, H. G.

    1987-03-01

    We have employed the TDPAC technique to measure the paramagnetic enhancement factor β of140Ce in CeRh3B2 in the temperature range 300 K down to 115 K. Our measurements show that above Tc=115 K, the trend for β(T) closely follows that for trivalent cerium.

  15. B2C social media value gap-model: a study of the Dutch online retailing

    NARCIS (Netherlands)

    Constantinides, Efthymios; Schepers, Lonieke; Vries, de Sjoerd

    2015-01-01

    Social media are extensively used by customers and businesses in the B2C domain but the objectives and the way the two parties use them are different. Based on the uses and gratifications theory, the article identifies similarities and differences in motives and use of social media in retailing. The

  16. Superconductivity in MgB2 : Phonon modes and influence of carbon doping

    Indian Academy of Sciences (India)

    A Bharathi; Y Hariharan; Jemima Balaselvi; C S Sundar

    2003-02-01

    Following a brief overview, results of our investigations on phonon modes in MgB2 , and superconducting transition in carbon doped MgB2 are presented. The superconducting transition temperature in MgB$_{2−x}C_x$ as obtained from susceptibility and resistivity measurements is observed to decrease systematically from 39.4 K for = 0 to 26 K for = 0.5S. It is shown the changes in lattice volume, as obtained from x-ray diffraction measurements, can account only partially for the observed decrease in $T_c$. The observed variation of $T_c$ with carbon content is seen to correlate with the Debye temperatures, obtained from an analysis of the resistivity data. Investigation of the phonon modes in MgB2 , through infrared absorption measurements indicate three modes at 410, 475 and 560 cm-1 The former two are associated with the infrared active modes, and the third component is associated with the Raman mode, that gets activated due to disorder. A study of the temperature dependence of these modes indicates no changes across the superconducting transition. The mode at 560 cm-1 shows a significant hardening and a corresponding decrease in linewidth, with the lowering of temperature, that can been accounted in terms of anharmonicity.

  17. Design study of a 10 MW MgB2 superconductor direct drive wind turbine generator

    NARCIS (Netherlands)

    Abrahamsen, A.B.; Magnusson, N.; Liu, D.; Stehouwer, E.; Hendriks, B.; Polinder, H.

    2014-01-01

    A superconducting direct drive generator based on field windings of MgB2 superconducting tape is proposed as a solution by mounting the generator in front of the blades using a king-pin nacelle design for offshore turbines with power ratings larger than 10 MW as investigated in the INNWIND.EU projec

  18. Design study of a 10 MW MgB2 superconductor direct drive wind turbine generator

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Magnusson, Niklas; Liu, Dong

    2014-01-01

    A superconducting direct drive generator based on field windings of MgB2 superconducting tape is proposed as a solution by mounting the generator in front of the blades using a king-pin nacelle design for offshore turbines with power ratings larger than 10 MW as investigated in the INNWIND.EU pro...

  19. Design of an MgB2 race track coil for a wind generator pole demonstration

    NARCIS (Netherlands)

    Abrahamsen, A.B.; Magnusson, N.; Jensen, B.B.; Liu, D.; Polinder, H.

    2014-01-01

    An MgB2 race track coil intended for demonstrating a down scaled pole of a 10 MW direct drive wind turbine generator has been designed. The coil consists of 10 double pancake coils stacked into a race track coil with a cross section of 84 mm x 80 mm. The length of the straight section is 0.5 m and t

  20. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Press correspondents employed by United States... GOVERNING DEPARTMENT OF STATE PRESS BUILDING PASSES § 9b.2 Press correspondents employed by United States media organizations. In order to obtain a Department of State press building pass, press...