WorldWideScience

Sample records for plasma core assembly

  1. Research on plasma core reactors

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    Jarvis, G.A.; Barton, D.M.; Helmick, H.H.; Bernard, W.; White, R.H.

    1977-01-01

    Experiments and theoretical studies are being conducted for NASA on critical assemblies with 1-m-diam by 1-m-long low-density cores surrounded by a thick beryllium reflector. These assemblies make extensive use of existing nuclear propulsion reactor components, facilities, and instrumentation. Due to excessive porosity in the reflector, the initial critical mass was 19 kg U(93.2). Addition of a 17-cm-thick by 89-cm-diam beryllium flux trap in the cavity reduced the critical mass to 7 kg when all the uranium was in the zone just outside the flux trap. A mockup aluminum UF/sub 6/ container was placed inside the flux trap and fueled with uranium-graphite elements. Fission distributions and reactivity worths of fuel and structural materials were measured. Finally, an 85,000-cm/sup 3/ aluminum canister in the central region was fueled with UF/sub 6/ gas and fission density distributions determined. These results will be used to guide the design of a prototype plasma core reactor which will test energy removal by optical radiation.

  2. Reconstitution of fuel assemblies and core components

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    Hummel, Wolfgang; Langenberger, Jan [AREVA NP GmbH (Germany)

    2012-11-01

    Due to AREVA's experience and big portfolio of techniques, reconstitution of fuel assemblies and core components at light water reactors is possible within a reasonable timeframe and with interesting cost benefit. Customer feedback indicates the sustainability of such reconstitutions. As a result, a long-term maintenance of value can be assured and early waste disposal can be avoided. (orig.)

  3. Plasma Pyrolysis Assembly Regeneration Evaluation

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    Medlen, Amber; Abney, Morgan B.; Miller, Lee A.

    2011-01-01

    In April 2010 the Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS). This technology requires hydrogen to recover oxygen from carbon dioxide. This results in the production of water and methane. Water is electrolyzed to provide oxygen to the crew. Methane is vented to space resulting in a loss of valuable hydrogen and unreduced carbon dioxide. This is not critical for ISS because of the water resupply from Earth. However, in order to have enough oxygen for long-term missions, it will be necessary to recover the hydrogen to maximize oxygen recovery. Thus, the Plasma Pyrolysis Assembly (PPA) was designed to recover hydrogen from methane. During operation, the PPA produces small amounts of carbon that can ultimately reduce performance by forming on the walls and windows of the reactor chamber. The carbon must be removed, although mechanical methods are highly inefficient, thus chemical methods are of greater interest. The purpose of this effort was to determine the feasibility of chemically removing the carbon from the walls and windows of a PPA reactor using a pure carbon dioxide stream.

  4. FBR core design with the composite fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Cappiello, M.W.

    Although calculations are preliminary, overall feasibility of an FBR core design with the composite fuel assembly has been demonstrated. The advantaged over the heterogeneous design is that large variances in assembly mixed mean outlet temperatures are eliminated. Also, the effective enrichment of an assembly may easily be adjusted by varying the number of fertile pins per assembly, thus making it possible to flatten the core radial power profile. The use of the composite fuel assembly may in the future offer a significant alternative to heterogeneous FBR core design.

  5. Electrode assemblies, plasma apparatuses and systems including electrode assemblies, and methods for generating plasma

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    Kong, Peter C; Grandy, Jon D; Detering, Brent A; Zuck, Larry D

    2013-09-17

    Electrode assemblies for plasma reactors include a structure or device for constraining an arc endpoint to a selected area or region on an electrode. In some embodiments, the structure or device may comprise one or more insulating members covering a portion of an electrode. In additional embodiments, the structure or device may provide a magnetic field configured to control a location of an arc endpoint on the electrode. Plasma generating modules, apparatus, and systems include such electrode assemblies. Methods for generating a plasma include covering at least a portion of a surface of an electrode with an electrically insulating member to constrain a location of an arc endpoint on the electrode. Additional methods for generating a plasma include generating a magnetic field to constrain a location of an arc endpoint on an electrode.

  6. Chaperone-assisted assembly of the proteasome core particle.

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    Matias, Ana C; Ramos, Paula C; Dohmen, R Jürgen

    2010-02-01

    The 26S proteasome is a non-lysosomal protease in the cytosol and nucleus of eukaryotic cells. Its main function is to mediate ubiquitin-dependent proteolysis. The 26S proteasome is a multimeric complex composed by the 20S proteasome CP (core particle) and the 19S RPs (regulatory particles). Although the atomic structure of the 26S proteasome has not yet been determined, high-resolution structures are available for its CP. Studies on the complicated assembly pathway of the proteasome have revealed that it involves an unprecedented number of dedicated chaperones. Assembly of the CP alone involves three conserved proteasome-assembly chaperones [PAC1-PAC2, PAC3-PAC4 and UMP1 (ubiquitin-mediated proteolysis 1)]. Whereas the two heterodimeric PACs have been implicated in the formation of rings of the seven distinct alpha subunits, UMP1 is important for the formation and dimerization of proteasome precursor complexes containing beta subunits. Dimerization coincides with the incorporation of the last beta subunit (beta7). Additional modules important for the assembly of precursor complexes and their dimerization reside in the beta subunits themselves, either as transient or as permanent extensions. Particularly important domains are the propeptide of beta5 and the C-terminal extensions of beta2 and beta7. Upon maturation of the active sites by autocatalytic processing, UMP1 is degraded by the native proteasome.

  7. A New Global Core Plasma Model of the Plasmasphere

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    Gallagher, D. L.; Comfort, R. H.; Craven, P. D.

    2014-01-01

    The Global Core Plasma Model (GCPM) is the first empirical model for thermal inner magnetospheric plasma designed to integrate previous models and observations into a continuous in value and gradient representation of typical total densities. New information about the plasmasphere, in particular, makes possible significant improvement. The IMAGE Mission Radio Plasma Imager (RPI) has obtained the first observations of total plasma densities along magnetic field lines in the plasmasphere and polar cap. Dynamics Explorer 1 Retarding Ion Mass Spectrometer (RIMS) has provided densities in temperatures in the plasmasphere for 5 ion species. These and other works enable a new more detailed empirical model of thermal in the inner magnetosphere that will be presented.

  8. Trafficking of hepatitis C virus core protein during virus particle assembly.

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    Natalie A Counihan

    2011-10-01

    Full Text Available Hepatitis C virus (HCV core protein is directed to the surface of lipid droplets (LD, a step that is essential for infectious virus production. However, the process by which core is recruited from LD into nascent virus particles is not well understood. To investigate the kinetics of core trafficking, we developed methods to image functional core protein in live, virus-producing cells. During the peak of virus assembly, core formed polarized caps on large, immotile LDs, adjacent to putative sites of assembly. In addition, LD-independent, motile puncta of core were found to traffic along microtubules. Importantly, core was recruited from LDs into these puncta, and interaction between the viral NS2 and NS3-4A proteins was essential for this recruitment process. These data reveal new aspects of core trafficking and identify a novel role for viral nonstructural proteins in virus particle assembly.

  9. Flat-band assembly for toroidal transformer cores

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    Mclyman, W. T.

    1973-01-01

    Toroidal transformer cores are often banded together by means of strap. Spot welds secure strap. Proper tension is obtained by use of special fixture in conjunction with winding of wire which is placed temporarily on core; winding is excited by dc current to hold core halves together magnetically during alignment.

  10. Core Physics and Kinetics Calculations for the Fissioning Plasma Core Reactor

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    Butler, C.; Albright, D.

    2007-01-01

    Highly efficient, compact nuclear reactors would provide high specific impulse spacecraft propulsion. This analysis and numerical simulation effort has focused on the technical feasibility issues related to the nuclear design characteristics of a novel reactor design. The Fissioning Plasma Core Reactor (FPCR) is a shockwave-driven gaseous-core nuclear reactor, which uses Magneto Hydrodynamic effects to generate electric power to be used for propulsion. The nuclear design of the system depends on two major calculations: core physics calculations and kinetics calculations. Presently, core physics calculations have concentrated on the use of the MCNP4C code. However, initial results from other codes such as COMBINE/VENTURE and SCALE4a. are also shown. Several significant modifications were made to the ISR-developed QCALC1 kinetics analysis code. These modifications include testing the state of the core materials, an improvement to the calculation of the material properties of the core, the addition of an adiabatic core temperature model and improvement of the first order reactivity correction model. The accuracy of these modifications has been verified, and the accuracy of the point-core kinetics model used by the QCALC1 code has also been validated. Previously calculated kinetics results for the FPCR were described in the ISR report, "QCALC1: A code for FPCR Kinetics Model Feasibility Analysis" dated June 1, 2002.

  11. Advanced Plasma Pyrolysis Assembly (PPA) Reactor and Process Development

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    Wheeler, Richard R., Jr.; Hadley, Neal M.; Dahl, Roger W.; Abney, Morgan B.; Greenwood, Zachary; Miller, Lee; Medlen, Amber

    2012-01-01

    Design and development of a second generation Plasma Pyrolysis Assembly (PPA) reactor is currently underway as part of NASA's Atmosphere Revitalization Resource Recovery effort. By recovering up to 75% of the hydrogen currently lost as methane in the Sabatier reactor effluent, the PPA helps to minimize life support resupply costs for extended duration missions. To date, second generation PPA development has demonstrated significant technology advancements over the first generation device by doubling the methane processing rate while, at the same time, more than halving the required power. One development area of particular interest to NASA system engineers is fouling of the PPA reactor with carbonaceous products. As a mitigation plan, NASA MSFC has explored the feasibility of using an oxidative plasma based upon metabolic CO2 to regenerate the reactor window and gas inlet ports. The results and implications of this testing are addressed along with the advanced PPA reactor development.

  12. Heat transfer analysis of fuel assemblies in a heterogeneous gas core nuclear rocket

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    Watanabe, Yoichi; Appelbaum, Jacob; Diaz, Nils; Maya, Isaac

    1991-01-01

    Heat transfer problems of a heterogeneous gaseous core nuclear rocket were studied. The reactor core consists of 1.5-m long hexagonal fuel assemblies filled with pressurized uranium tetrafluoride (UF4) gas. The fuel gas temperature ranges from 3500 to 7000 K at a nominal operating condition of 40 atm. Each fuel assembly has seven coolant tubes, through which hydrogen propellant flows. The propellant temperature is not constrained by the fuel temperature but by the maximum temperature of the graphite coolant tube. For a core achieving a fission power density of 1000 MW/cu m, the propellant core exit temperature can be as high as 3200 K. The physical size of a 1250 MW gaseous core nuclear rocket is comparable with that of a NERVA-type solid core nuclear rocket. The engine can deliver a specific impulse of 1020 seconds and a thrust of 330 kN.

  13. Filtration of Carbon Particulate Emissions from a Plasma Pyrolysis Assembly

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    Agui, Juan H.; Green, Robert; Vijayakumar, R.; Berger, Gordon; Greenwood, Zach; Abney, Morgan; Peterson, Elspeth

    2016-01-01

    NASA is investigating plasma pyrolysis as a candidate technology that will enable the recovery of hydrogen from the methane produced by the ISS Sabatier Reactor. The Plasma Pyrolysis Assembly (PPA) is the current prototype of this technology which converts the methane product from the Carbon Dioxide Reduction Assembly (CRA) to acetylene and hydrogen with 90% or greater conversion efficiency. A small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on several options for filtering out the carbon particulate emissions from the PPA exit gas stream. The filtration technologies and concepts investigated range from fibrous media to monolithic ceramic and sintered metal media. This paper describes the different developed filter prototypes and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC. In addition, characterization data on the generated carbon particulates, that help to define filter requirements, are also presented.

  14. 3.5A cryoEM structure of hepatitis B virus core assembled from full-length core protein.

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    Xuekui Yu

    Full Text Available The capsid shell of infectious hepatitis B virus (HBV is composed of 240 copies of a single protein called HBV core antigen (HBc. An atomic model of a core assembled from truncated HBc was determined previously by X-ray crystallography. In an attempt to obtain atomic structural information of HBV core in a near native, non-crystalline environment, we reconstructed a 3.5Å-resolution structure of a recombinant core assembled from full-length HBc by cryo electron microscopy (cryoEM and derived an atomic model. The structure shows that the 240 molecules of full-length HBc form a core with two layers. The outer layer, composed of the N-terminal assembly domain, is similar to the crystal structure of the truncated HBc, but has three differences. First, unlike the crystal structure, our cryoEM structure shows no disulfide bond between the Cys61 residues of the two subunits within the dimer building block, indicating such bond is not required for core formation. Second, our cryoEM structure reveals up to four more residues in the linker region (amino acids 140-149. Third, the loops in the cryoEM structures containing this linker region in subunits B and C are oriented differently (~30° and ~90° from their counterparts in the crystal structure. The inner layer, composed of the C-terminal arginine-rich domain (ARD and the ARD-bound RNAs, is partially-ordered and connected with the outer layer through linkers positioned around the two-fold axes. Weak densities emanate from the rims of positively charged channels through the icosahedral three-fold and local three-fold axes. We attribute these densities to the exposed portions of some ARDs, thus explaining ARD's accessibility by proteases and antibodies. Our data supports a role of ARD in mediating communication between inside and outside of the core during HBV maturation and envelopment.

  15. Controlled assembly and plasmonic properties of asymmetric core-satellite nanoassemblies.

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    Yoon, Jun Hee; Lim, Jonghui; Yoon, Sangwoon

    2012-08-28

    The assembly of noble metal nanoparticles offers an appealing means to control and enhance the plasmonic properties of nanostructures. However, making nanoassemblies with easily modifiable gap distances with high efficiency has been challenging. Here, we report a novel strategy to assemble gold nanoparticles (AuNPs) into Janus-type asymmetric core-satellite nanostructures. Markedly different desorption efficiency between large and small AuNPs in ethanol allows us to prepare the asymmetric core-satellite nanoassemblies in a dispersed colloidal state with near 100% purity. The resulting nanoassemblies have well-defined structures in which a core AuNP (51 nm) is covered by an average of 13 ± 3 satellite AuNPs (13 nm) with part of the core surfaces left unoccupied. Strong surface plasmon coupling is observed from these nanoassemblies as a result of the close proximity between the core and the satellites, which appears significantly red-shifted from the surface plasmon resonance frequencies of the constituting nanoparticles. The dependence of the surface plasmon coupling on a gap distance of less than 3 nm is systematically investigated by varying the length of the alkanedithiol linkers. The asymmetric core-satellite nanoassemblies also serve as an excellent surface-enhanced Raman scattering substrate with an enhancement factor of ~10(6). Finally, we demonstrate that the presented assembly method is extendible to the preparation of compositionally heterogeneous core-satellite nanoassemblies.

  16. High temperature UF6 RF plasma experiments applicable to uranium plasma core reactors

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    Roman, W. C.

    1979-01-01

    An investigation was conducted using a 1.2 MW RF induction heater facility to aid in developing the technology necessary for designing a self critical fissioning uranium plasma core reactor. Pure, high temperature uranium hexafluoride (UF6) was injected into an argon fluid mechanically confined, steady state, RF heated plasma while employing different exhaust systems and diagnostic techniques to simulate and investigate some potential characteristics of uranium plasma core nuclear reactors. The development of techniques and equipment for fluid mechanical confinement of RF heated uranium plasmas with a high density of uranium vapor within the plasma, while simultaneously minimizing deposition of uranium and uranium compounds on the test chamber peripheral wall, endwall surfaces, and primary exhaust ducts, is discussed. The material tests and handling techniques suitable for use with high temperature, high pressure, gaseous UF6 are described and the development of complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma, effluent exhaust gases, and residue deposited on the test chamber and exhaust system components is reported.

  17. Self-assembly of core-satellite gold nanoparticles for colorimetric detection of copper ions.

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    Weng, Ziqing; Wang, Hongbin; Vongsvivut, Jitraporn; Li, Runqing; Glushenkov, Alexey M; He, Jin; Chen, Ying; Barrow, Colin J; Yang, Wenrong

    2013-11-25

    Molecule-coated nanoparticles are hybrid materials which can be engineered with novel properties. The molecular coating of metal nanoparticles can provide chemical functionality, enabling assembly of the nanoparticles that are important for applications, such as biosensing devices. Herein, we report a new self-assembly of core-satellite gold nanoparticles linked by a simple amino acid l-Cysteine for biosensing of Cu(2+). The plasmonic properties of core-satellite nano-assemblies were investigated, a new red shifted absorbance peak from about 600 to 800 nm was found, with specific wavelength depending on ratios with assembly of large and small gold nanoparticles. The spectral features obtained using surface-enhanced Raman spectroscopy (SERS) provided strong evidence for the assembly of the Cu(2+) ions to the L-Cysteine molecules leading to the successful formation of the core-satellite Cu(l-Cysteine) complex on the gold surfaces. In addition, a linear relationship between the concentration of mediating Cu(2+) and absorbance of self-assembled gold nanoparticles (GNPs) at 680 nm was obtained. These results strongly address the potential strategy for applying the functionalized GNPs as novel biosensing tools in trace detections of certain metal ions.

  18. The hepatitis B virus core protein intradimer interface modulates capsid assembly and stability.

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    Selzer, Lisa; Katen, Sarah P; Zlotnick, Adam

    2014-09-02

    During the hepatitis B virus (HBV) life cycle, capsid assembly and disassembly must ensure correct packaging and release of the viral genome. Here we show that changes in the dynamics of the core protein play an important role in regulating these processes. The HBV capsid assembles from 120 copies of the core protein homodimer. Each monomer contains a conserved cysteine at position 61 that can form an intradimer disulfide that we use as a marker for dimer conformational states. We show that dimers in the context of capsids form intradimer disulfides relatively rapidly. Surprisingly, compared to reduced dimers, fully oxidized dimers assembled slower and into capsids that were morphologically similar but less stable. We hypothesize that oxidized protein adopts a geometry (or constellation of geometries) that is unfavorable for capsid assembly, resulting in weaker dimer-dimer interactions as well as slower assembly kinetics. Our results suggest that structural flexibility at the core protein intradimer interface is essential for regulating capsid assembly and stability. We further suggest that capsid destabilization by the C61-C61 disulfide has a regulatory function to support capsid disassembly and release of the viral genome.

  19. Data for ion and seed dependent fibril assembly of a spidroin core domain

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    Martin Humenik

    2015-09-01

    Full Text Available This data article includes size exclusion chromatography data of soluble eADF4(C16, an engineered spider silk variant based on the core domain sequence of the natural dragline silk protein ADF4 of Araneus diadematus, in combination with light scattering; the protein is monomeric before assembly. The assembled mature fibrils were visualized by transmission electron microscopy (TEM and atomic force microscopy (AFM. Sonicated fibrils were used as seeds to by-pass the nucleation lag phase in eADF4(C16 assembly. We also provide data on the sedimentation kinetics of spider silk in the presence of different NaCl concentrations revealing very slow protein aggregation in comparison to the fast assembly triggered by phosphate ions published previously [1]. Experiments in the Data article represent supporting material for our work published recently [1], which described the assembly mechanism of recombinant eADF4(C16 fibrils.

  20. Supercooling Self-Assembly of Magnetic Shelled Core/Shell Supraparticles.

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    Zheng, Xiaotong; Yan, Bingyun; Wu, Fengluan; Zhang, Jinlong; Qu, Shuxin; Zhou, Shaobing; Weng, Jie

    2016-09-14

    Molecular self-assembly has emerged as a powerful technique for controlling the structure and properties of core/shell structured supraparticles. However, drug-loading capacities and therapeutic effects of self-assembled magnetic core/shell nanocarriers with magnetic nanoparticles in the core are limited by the intervention of the outer organic or inorganic shell, the aggregation of superparamagnetic nanoparticles, the narrowed inner cavity, etc. Here, we present a self-assembly approach based on rebalancing hydrogen bonds between components under a supercooling process to form a new core/shell nanoscale supraparticle with magnetic nanoparticles as the shell and a polysaccharide as a core. Compared with conventional iron oxide nanoparticles, this magnetic shelled core/shell nanoparticle possesses an optimized inner cavity and a loss-free outer magnetic property. Furthermore, we find that the drug-loaded magnetic shelled nanocarriers showed interesting in vitro release behaviors at different pH conditions, including "swelling-broken", "dissociating-broken", and "bursting-broken" modes. Our experiments demonstrate the novel design of the multifunctional hybrid nanostructure and provide a considerable potential for the biomedical applications.

  1. Rab33B Controls Hepatitis B Virus Assembly by Regulating Core Membrane Association and Nucleocapsid Processing.

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    Bartusch, Christina; Döring, Tatjana; Prange, Reinhild

    2017-06-21

    Many viruses take advantage of cellular trafficking machineries to assemble and release new infectious particles. Using RNA interference (RNAi), we demonstrate that the Golgi/autophagosome-associated Rab33B is required for hepatitis B virus (HBV) propagation in hepatoma cell lines. While Rab33B is dispensable for the secretion of HBV subviral envelope particles, its knockdown reduced the virus yield to 20% and inhibited nucleocapsid (NC) formation and/or NC trafficking. The overexpression of a GDP-restricted Rab33B mutant phenocopied the effect of deficit Rab33B, indicating that Rab33B-specific effector proteins may be involved. Moreover, we found that HBV replication enhanced Rab33B expression. By analyzing HBV infection cycle steps, we identified a hitherto unknown membrane targeting module in the highly basic C-terminal domain of the NC-forming core protein. Rab33B inactivation reduced core membrane association, suggesting that membrane platforms participate in HBV assembly reactions. Biochemical and immunofluorescence analyses provided further hints that the viral core, rather than the envelope, is the main target for Rab33B intervention. Rab33B-deficiency reduced core protein levels without affecting viral transcription and hampered core/NC sorting to envelope-positive, intracellular compartments. Together, these results indicate that Rab33B is an important player in intracellular HBV trafficking events, guiding core transport to NC assembly sites and/or NC transport to budding sites.

  2. Analysis of suprathermal nuclear processes in the solar core plasma

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    Voronchev, Victor T.; Nakao, Yasuyuki; Watanabe, Yukinobu

    2017-04-01

    A consistent model for the description of suprathermal processes in the solar core plasma naturally triggered by fast particles generated in exoergic nuclear reactions is formulated. This model, based on the formalism of in-flight reaction probability, operates with different methods of treating particle slow-down in the plasma, and allows for the influence of electron degeneracy and electron screening on processes in the matter. The model is applied to examine slowing-down of 8.7 MeV α-particles produced in the {}7{Li}(p,α )α reaction of the pp chain, and to analyze suprathermal processes in the solar CNO cycle induced by them. Particular attention is paid to the suprathermal {}14{{N}}{(α ,{{p}})}17{{O}} reaction unappreciated in standard solar model simulations. It is found that an appreciable non-standard (α ,p) nuclear flow due to this reaction appears in the matter and modifies running of the CNO cycle in ∼95% of the solar core region. In this region at R> 0.1{R}ȯ , normal branching of nuclear flow {}14{{N}}≤ftarrow {}17{{O}}\\to {(}18{{F}})\\to {}18{{O}} transforms to abnormal sequential flow {}14{{N}}\\to {}17{{O}}\\to {(}18{{F}})\\to {}18{{O}}, altering some element abundances. In particular, nuclear network calculations reveal that in the outer core the abundances of 17O and 18O isotopes can increase by a factor of 20 as compared with standard estimates. A conjecture is made that other CNO suprathermal (α ,p) reactions may also affect abundances of CNO elements, including those generating solar neutrinos.

  3. Infrared Absorption Spectroscopic Study on Reaction between Self-Assembled Monolayers and Atmospheric-Pressure Plasma

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    Masanori Shinohara

    2015-01-01

    Full Text Available Plasma is becoming increasingly adopted in bioapplications such as plasma medicine and agriculture. This study investigates the interaction between plasma and molecules in living tissues, focusing on plasma-protein interactions. To this end, the reaction of air-pressure air plasma with NH2-terminated self-assembled monolayer is investigated by infrared spectroscopy in multiple internal reflection geometry. The atmospheric-pressure plasma decomposed the NH2 components, the characteristic units of proteins. The decomposition is attributed to water clusters generated in the plasma, indicating that protein decomposition by plasma requires humid air.

  4. Structural and Biochemical Insights into MLL1 Core Complex Assembly

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    Avdic, Vanja; Zhang, Pamela; Lanouette, Sylvain; Groulx, Adam; Tremblay, Véronique; Brunzelle, Joseph; Couture, Jean-François (Ottawa); (NWU)

    2012-05-02

    Histone H3 Lys-4 methylation is predominantly catalyzed by a family of methyltransferases whose enzymatic activity depends on their interaction with a three-subunit complex composed of WDR5, RbBP5, and Ash2L. Here, we report that a segment of 50 residues of RbBP5 bridges the Ash2L C-terminal domain to WDR5. The crystal structure of WDR5 in ternary complex with RbBP5 and MLL1 reveals that both proteins binds peptide-binding clefts located on opposite sides of WDR5s {beta}-propeller domain. RbBP5 engages in several hydrogen bonds and van der Waals contacts within a V-shaped cleft formed by the junction of two blades on WDR5. Mutational analyses of both the WDR5 V-shaped cleft and RbBP5 residues reveal that the interactions between RbBP5 and WDR5 are important for the stimulation of MLL1 methyltransferase activity. Overall, this study provides the structural basis underlying the formation of the WDR5-RbBP5 subcomplex and further highlight the crucial role of WDR5 in scaffolding the MLL1 core complex.

  5. Two-wavelength LIDAR Thomson scattering for ITER core plasma

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    Nielsen, P.; Gowers, C.; Salzmann, H.

    2017-07-01

    Our proposal for a LIDAR Thomson scattering system to measure Te and ne profiles in the ITER core plasma, is based on experience with the LIDAR system on JET, which is still operational after 30 years. The design uses currently available technology and complies with the measurement requirements given by ITER. In addition, it offers the following advantages over the conventional imaging approach currently being adopted by ITER: 1) No gas fill of the vessel required for absolute calibration. 2) Easier alignment. 3) Measurements over almost the complete plasma diameter. 4) Two mirrors only as front optics. For a given laser wavelength the dynamic range of the Te measurements is mainly limited by the collection optics' transmission roll-off in the blue and the range of spectral sensitivity of the required fast photomultipliers. With the originally proposed Ti:Sapphire laser, measurements of the envisaged maximum temperature of 40 keV are marginally possible. Here we present encouraging simulation results on the use of other laser systems and on the use of two lasers with different wavelength. Alternating two wavelengths was proposed already in 1997 as a method for calibrating the transmission of the collection system. In the present analysis, the two laser pulses are injected simultaneously. We find that the use of Nd:YAG lasers operated at fundamental and second harmonic, respectively, yields excellent results and preserves the spectral recalibration feature.

  6. Polymer-virus core-shell structures prepared via co-assembly and template synthesis methods

    Institute of Scientific and Technical Information of China (English)

    SUTHIWANGCHAROEN; Nisaraporn; PREVELIGE; Peter; E.Jr

    2010-01-01

    Bionanoparticles(BNPs),consisting of virus and virus-like assemblies,have attracted much attention in the biomedical field for their applications such as imaging and targeted drug delivery,owing to their well-defined structures and well-controlled chemistries.BNPs-based core-shell structures provide a unique system for the investigation of biological interactions such as protein-protein and protein-carbohydrate interactions.However,it is still a challenge to prepare the BNPs-based core-shell structures.Herein,we describe(i) co-assembly method and(ii) template synthesis method in the development of polymer-BNPs core-shell structures.These two methods can be divided into three different systems.In system A,different polymers including poly(2-vinylpyridine)(P2VP),poly(4-vinylpyridine)(P4VP) and poly(ε-caprolactone)-block-poly(2-vinylpyridine)(PCL-b-P2VP) can form a raspberry-like structure with BNPs.In system B,polystyrene(PS) spheres end capped with free amine and BNPs can form a core-shell structure.In System C,layer-by-layer(LBL) method is used to prepare positive charged PS particles,which can be used as a template to form the core-shell structures with BNPs.These two methods may open a new way for preparing novel protein-based functional materials for potential applications in the biomedical field.

  7. Preliminary Thermal Hydraulic Analyses of the Conceptual Core Models with Tubular Type Fuel Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Hee Taek; Park, Jong Hark; Park, Cheol

    2006-11-15

    A new research reactor (AHR, Advanced HANARO Reactor) based on the HANARO has being conceptually developed for the future needs of research reactors. A tubular type fuel was considered as one of the fuel options of the AHR. A tubular type fuel assembly has several curved fuel plates arranged with a constant small gap to build up cooling channels, which is very similar to an annulus pipe with many layers. This report presents the preliminary analysis of thermal hydraulic characteristics and safety margins for three conceptual core models using tubular fuel assemblies. Four design criteria, which are the fuel temperature, ONB (Onset of Nucleate Boiling) margin, minimum DNBR (Departure from Nucleate Boiling Ratio) and OFIR (Onset of Flow Instability Ratio), were investigated along with various core flow velocities in the normal operating conditions. And the primary coolant flow rate based a conceptual core model was suggested as a design information for the process design of the primary cooling system. The computational fluid dynamics analysis was also carried out to evaluate the coolant velocity distributions between tubular channels and the pressure drop characteristics of the tubular fuel assembly.

  8. Self-assembling SAS-6 multimer is a core centriole building block.

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    Gopalakrishnan, Jayachandran; Guichard, Paul; Smith, Andrew H; Schwarz, Heinz; Agard, David A; Marco, Sergio; Avidor-Reiss, Tomer

    2010-03-19

    Centrioles are conserved microtubule-based organelles with 9-fold symmetry that are essential for cilia and mitotic spindle formation. A conserved structure at the onset of centriole assembly is a "cartwheel" with 9-fold radial symmetry and a central tubule in its core. It remains unclear how the cartwheel is formed. The conserved centriole protein, SAS-6, is a cartwheel component that functions early in centriole formation. Here, combining biochemistry and electron microscopy, we characterize SAS-6 and show that it self-assembles into stable tetramers, which serve as building blocks for the central tubule. These results suggest that SAS-6 self-assembly may be an initial step in the formation of the cartwheel that provides the 9-fold symmetry. Electron microscopy of centrosomes identified 25-nm central tubules with repeating subunits and show that SAS-6 concentrates at the core of the cartwheel. Recombinant and native SAS-6 self-oligomerizes into tetramers with approximately 6-nm subunits, and these tetramers are components of the centrosome, suggesting that tetramers are the building blocks of the central tubule. This is further supported by the observation that elevated levels of SAS-6 in Drosophila cells resulted in higher order structures resembling central tubule morphology. Finally, in the presence of embryonic extract, SAS-6 tetramers assembled into high density complexes, providing a starting point for the eventual in vitro reconstruction of centrioles.

  9. KALIMER-600-clad Core Fuel Assembly Calculation using MATRA-LMR (V2.0) Code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Gyun; Kim, Young Il

    2006-12-15

    Since the sodium boiling point is very high, maximum cladding and pin temperatures are used for design limit condition in sodium cooled liquid metal reactor. It is necessary to predict accurately the temperature distribution in the core and in the subassemblies to increase the sodium coolant efficiency. Based on the MATRA code, which is developed for PWR analysis, MATRA-LMR has been developed for SFR. The major modifications are: the sodium properties table is implemented as subprogram in the code, Heat transfer coefficients are changed for SFR, te pressure drop correlations are changed for more accurate calculations, which are Novendstern, Chiu-Rohsenow-Todreas, and Cheng-Todreas correlations. This This report describes briefly code structure and equations of MATRA-LMR (Version 2.0), explains input data preparation and shows some calculation results for the KALIMER-600-clad core fuel assembly for which has been performed the conceptual design of the core in the year 2006.

  10. Assembly of nucleosomal arrays from recombinant core histones and nucleosome positioning DNA.

    Science.gov (United States)

    Rogge, Ryan A; Kalashnikova, Anna A; Muthurajan, Uma M; Porter-Goff, Mary E; Luger, Karolin; Hansen, Jeffrey C

    2013-09-10

    Core histone octamers that are repetitively spaced along a DNA molecule are called nucleosomal arrays. Nucleosomal arrays are obtained in one of two ways: purification from in vivo sources, or reconstitution in vitro from recombinant core histones and tandemly repeated nucleosome positioning DNA. The latter method has the benefit of allowing for the assembly of a more compositionally uniform and precisely positioned nucleosomal array. Sedimentation velocity experiments in the analytical ultracentrifuge yield information about the size and shape of macromolecules by analyzing the rate at which they migrate through solution under centrifugal force. This technique, along with atomic force microscopy, can be used for quality control, ensuring that the majority of DNA templates are saturated with nucleosomes after reconstitution. Here we describe the protocols necessary to reconstitute milligram quantities of length and compositionally defined nucleosomal arrays suitable for biochemical and biophysical studies of chromatin structure and function.

  11. Operational experience with a variety of plasma facing tile assemblies at JET

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, P. E-mail: paul.edwards@jet.uk; Altmann, H.; Loving, A.; Pedrick, L.; Tait, J.; Way, M

    2001-10-01

    During the June 1999 JET shutdown, 3000 plasma facing Tile Assemblies were found to be loose and had to be re-torqued remotely using the Mascot force reflecting manipulator. Whilst the integrity of these Tile Assemblies has been monitored during previous man access shutdowns, with the introduction of tritium to the machine in May 1996, the majority had not been checked since March 1996. This paper reviews typical plasma facing Tile Assembly designs within the JET torus and summarises the experience gained for use in future machine applications. This includes loosening processes/mechanisms and their prevention, applications of surface coatings to avoid seizing of un-lubricated assemblies, and the use of vibration resistant thread profiles. The design of attachments to minimise combined mechanical and thermal stresses in the tiles, material selection and other engineering aspects are also discussed.

  12. Pendulum support of the W7-X plasma vessel: Design, tests, manufacturing, assembly, critical aspects, status

    Energy Technology Data Exchange (ETDEWEB)

    Missal, B., E-mail: bernd.missal@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstraße 1, D-17491 Greifswald (Germany); Leher, F.; Schiller, T. [MAN Diesel and Turbo SE, Werftstraße 17, 94469 Deggendorf (Germany); Friedrich, P. [Universität Rostock, FB Maschinenbau und Schiffstechnik, Albert-Einsteins-Straße 2, 18051 Rostock (Germany); Capriccioli, A. [ENEA Frascati, Fusion Technology Unit, Frascati (Italy)

    2014-10-15

    Highlights: • Plasma vessel support has to allow vertical adjustment and horizontal passive movement. • Planar sliding tables with PTFE do not fulfill all requirements. • Pendulums can fulfill all requirements. • Geometry and material of spherical bearings had to be optimized in calculations and tests. • Optimized pendulums were manufactured and assembled. - Abstract: The superconducting helical advanced stellarator Wendelstein 7-X (W7-X) is under construction at the Max-Planck-Institut für Plasmaphysik (IPP) in Greifswald, Germany. The three dimensional shape of plasma will be generated by 50 non-planar magnetic coils. The plasma vessel geometry follows exactly this three dimensional shape of plasma. To ensure the superconductivity of coils a cryo vacuum has to be generated. Therefore the coils and their support structure are enclosed within the outer vessel. Plasma vessel, coil structures and outer vessel have to be supported separately. This paper will describe the vertical supports of plasma vessel which have to fulfill two special requirements, vertical adjustability and horizontal mobility. These two tasks will be carried out by plasma vessel supports (PVS) with hydraulic cylinders, special sliding tables during assembly and pendulum supports during operating phase. The paper will give an overview of design, calculation, tests, fabrication, assembly, critical aspects and status of PVS.

  13. RAFT Synthesis and Self-Assembly of Free-Base Porphyrin Cored Star Polymers

    Directory of Open Access Journals (Sweden)

    Lin Wu

    2011-01-01

    Full Text Available Reversible addition fragmentation chain transfer (RAFT synthesis and self-assembly of free-base porphyrin cored star polymers are reported. The polymerization, in the presence of a free-base porphyrin cored chain transfer agent (CTA-FBP, produced porphyrin star polymers with controlled molecular weights and narrow polydispersities for a number of monomers including N, N-dimethylacrylamide (DMA and styrene (St. Well-defined amphiphilic star block copolymers, P-(PS-PDMA4 and P-(PDMA-PS4 (P: porphyrin, were also prepared and used for self-assembly studies. In methanol, a selective solvent for PDMA, spherical micelles were observed for both block copolymers as characterized by TEM. UV-vis studies suggested star-like micelles were formed from P-(PS-PDMA4, while P-(PDMA-PS4 aggregated into flower-like micelles. Spectrophotometric titrations indicated that the optical response of these two micelles to external ions was a function of micellar structures. These structure-related properties will be used for micelle studies and functional material development in the future.

  14. Westinghouse Fuel Assemblies Performance after Operation in South-Ukraine NPP Mixed Core

    Energy Technology Data Exchange (ETDEWEB)

    Abdullayev, A. M.; Kulish, G. V.; Slyeptsov, O.; Slyeptsov, S.; Aleshin, Y.; Sparrow, S.; Lashevych, P.; Sokolov, D.; Latorre, Richard

    2013-09-14

    The evaluation of WWER-1000 Westinghouse fuel performance was done using the results of post–irradiation examinations of six LTAs and the WFA reload batches that have operated normally in mixed cores at South-Ukraine NPP, Unit-3 and Unit-2. The data on WFA/LTA elongation, FR growth and bow, WFA bow and twist, RCCA drag force and drag work, RCCA drop time, FR cladding integrity as well as the visual observation of fuel assemblies obtained during the 2006-2012 outages was utilized. The analysis of the measured data showed that assembly growth, FR bow, irradiation growth, and Zr-1%Nb grid and ZIRLO cladding corrosion lies within the design limits. The RCCA drop time measured for the LTA/WFA is about 1.9 s at BOC and practically does not change at EOC. The measured WFA bow and twist, and data of drag work on RCCA insertion showed that the WFA deformation in the mixed core is mostly controlled by the distortion of Russian FAs (TVSA) having the higher lateral stiffness. The visual inspection of WFAs carried out during the 2012 outages revealed some damage to the Zr-1%Nb grid outer strap for some WFAs during the loading sequence. The performed fundamental investigations allowed identifying the root cause of grid outer strap deformation and proposing the WFA design modifications for preventing damage to SG at a 225 kg handling trip limit.

  15. Analysis of Advanced Fuel Assemblies and Core Designs for the Current and Next Generations of LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Ragusa, Jean; Vierow, Karen

    2011-09-01

    The objective of the project is to design and analyze advanced fuel assemblies for use in current and future light water reactors and to assess their ability to reduce the inventory of transuranic elements, while preserving operational safety. The reprocessing of spent nuclear fuel can delay or avoid the need for a second geological repository in the US. Current light water reactor fuel assembly designs under investigation could reduce the plutonium inventory of reprocessed fuel. Nevertheless, these designs are not effective in stabilizing or reducing the inventory of minor actinides. In the course of this project, we developed and analyzed advanced fuel assembly designs with improved thermal transmutation capability regarding transuranic elements and especially minor actinides. These designs will be intended for use in thermal spectrum (e.g., current and future fleet of light water reactors in the US). We investigated various fuel types, namely high burn-up advanced mixed oxides and inert matrix fuels, in various geometrical designs that are compliant with the core internals of current and future light water reactors. Neutronic/thermal hydraulic effects were included. Transmutation efficiency and safety parameters were used to rank and down-select the various designs.

  16. Microwave-driven plasmas in Hollow-Core Photonic Crystal Fibres

    Science.gov (United States)

    Alves, L. L.; Leroy, O.; Boisse-Laporte, C.; Leprince, P.; Debord, B.; Gerome, F.; Jamier, R.; Benabid, F.

    2013-09-01

    This paper reports on a novel solution to ignite and maintain micro-plasmas in gas-filled Hollow-Core Photonic Crystal Fibres (HC-PCFs), using CW microwave excitation (2.45 GHz). The original concept is based on a surfatron, generating argon micro-plasmas of few centimetres in length within a 100 μm core-diameter Kagome HC-PCF, at ~1 mbar on-gap gas-pressure using low powers (core diameter, pressure and electron density). Work supported by ANR and DGA (ASTRID-2011-UVfactor) and by FCT (Pest-OE/SADG/LA0010/2011).

  17. Efficient Graph Based Assembly of Short-Read Sequences on Hybrid Core Architecture

    Energy Technology Data Exchange (ETDEWEB)

    Sczyrba, Alex; Pratap, Abhishek; Canon, Shane; Han, James; Copeland, Alex; Wang, Zhong; Brewer, Tony; Soper, David; D' Jamoos, Mike; Collins, Kirby; Vacek, George

    2011-03-22

    Advanced architectures can deliver dramatically increased throughput for genomics and proteomics applications, reducing time-to-completion in some cases from days to minutes. One such architecture, hybrid-core computing, marries a traditional x86 environment with a reconfigurable coprocessor, based on field programmable gate array (FPGA) technology. In addition to higher throughput, increased performance can fundamentally improve research quality by allowing more accurate, previously impractical approaches. We will discuss the approach used by Convey?s de Bruijn graph constructor for short-read, de-novo assembly. Bioinformatics applications that have random access patterns to large memory spaces, such as graph-based algorithms, experience memory performance limitations on cache-based x86 servers. Convey?s highly parallel memory subsystem allows application-specific logic to simultaneously access 8192 individual words in memory, significantly increasing effective memory bandwidth over cache-based memory systems. Many algorithms, such as Velvet and other de Bruijn graph based, short-read, de-novo assemblers, can greatly benefit from this type of memory architecture. Furthermore, small data type operations (four nucleotides can be represented in two bits) make more efficient use of logic gates than the data types dictated by conventional programming models.JGI is comparing the performance of Convey?s graph constructor and Velvet on both synthetic and real data. We will present preliminary results on memory usage and run time metrics for various data sets with different sizes, from small microbial and fungal genomes to very large cow rumen metagenome. For genomes with references we will also present assembly quality comparisons between the two assemblers.

  18. Galaxy and Mass Assembly (GAMA): survey diagnostics and core data release

    CERN Document Server

    Driver, S P; Kelvin, L S; Robotham, A S G; Liske, J; Norberg, P; Baldry, I K; Bamford, S P; Hopkins, A M; Loveday, J; Peacock, J A; Andrae, E; Bland-Hawthorn, J; Brough, S; Brown, M J I; Cameron, E; Ching, J H Y; Colless, M; Conselice, C J; Croom, S M; Cross, N J G; De Propris, R; Dye, S; Drinkwater, M J; Ellis, S; Graham, Alister W; Grootes, M W; Gunawardhana, M; Jones, D H; van Kampen, E; Maraston, C; Nichol, R C; Parkinson, H R; Phillipps, S; Pimbblet, K; Popescu, C C; Prescott, M; Roseboom, I G; Sadler, E M; Sansom, A E; Sharp, R G; Smith, D J B; Taylor, E; Thomas, D; Tuffs, R J; Wijesinghe, D; Dunne, L; Frenk, C S; Jarvis, M J; Madore, B F; Meyer, M J; Seibert, M; Staveley-Smith, L; Sutherland, W J; Warren, S J

    2010-01-01

    The Galaxy And Mass Assembly (GAMA) survey has been operating since February 2008 on the 3.9-m Anglo-Australian Telescope using the AAOmega fibre-fed spectrograph facility to acquire spectra with a resolution of R~1300 for 120,862 SDSS selected galaxies. The target catalogue constitutes three contiguous equatorial regions centred at 9h (G09), 12h (G12) and 14.5h (G15) each of 12 x 4 sq.deg to limiting fluxes of r < 19.4, r < 19.8, and r < 19.4 mag respectively (and additional limits at other wavelengths). Spectra and reliable redshifts have been acquired for over 98 per cent of the galaxies within these limits. Here we present the survey footprint, progression, data reduction, redshifting, re-redshifting, an assessment of data quality after 3 years, additional image analysis products (including ugrizYJHK photometry, Sersic profiles and photometric redshifts), observing mask, and construction of our core survey catalogue (GamaCore). From this we create three science ready catalogues: GamaCoreDR1 for p...

  19. HIS-TORIC: extending core ICRF wave simulation to include realistic SOL plasmas

    Science.gov (United States)

    Shiraiwa, S.; Wright, J. C.; Lee, J. P.; Bonoli, P. T.

    2017-08-01

    This paper presents a novel approach to incorporating an arbitrarily shaped edge scrape-off-layer (SOL) plasma and an ion cyclotron range of frequency (ICRF) antenna structure into existing core ICRF wave simulation models. We partition the entire computation domain into two sub-domains: a core and an edge region. Simulations in each domain are performed separately with appropriate numerical solvers. For the core, the TORIC ICRF solver (Brambilla 1999 Plasma Phys. Control. Fusion 41 1) was modified to impose an essential (Dirichlet) boundary condition at its interface with the edge domain. In the edge, a finite element method is used to solve a cold collisional plasma model. The domains are then joined together using the continuity boundary condition for the tangential electric and magnetic fields at their interfaces (Hybrid Integration of SOL to TORIC: HIS-TORIC). The model developed here was tested using an ICRH H minority heating scenario on the Alcator C-Mod tokamak (Hutchinson et al 1994 Phys. Plasmas 1 1511). The simulated pattern of core wave propagation agrees well with a standard TORIC simulation. This approach opens the possibility of using a realistic diverted SOL plasma and a complicated 3D RF antenna together with a rigorous hot core plasma model, while requiring only minimal modification to existing RF codes.

  20. Patterning functional materials using channel diffused plasma-etched self-assembled monolayer templates

    NARCIS (Netherlands)

    George, A.; Maijenburg, A.W.; Maas, M.G.; Blank, David H.A.; ten Elshof, Johan E.

    2011-01-01

    A simple and cost-effective methodology for large-area micrometer-scale patterning of a wide range of metallic and oxidic functional materials is presented. Self-assembled monolayers (SAM) of alkyl thiols on Au were micropatterned by channel-diffused oxygen plasma etching, a method in which selected

  1. High Temperature Stress Analysis on 61-pin Test Assembly for Reactor Core Sub-channel Flow Test

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongwon; Kim, Hyungmo; Lee, Hyeongyeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this study, a high temperature heat transfer and stress analysis of a 61-pin test fuel assembly scaled down from the full scale 217-pin sub-assembly was conducted. The reactor core subchannel flow characteristic test will be conducted to evaluate uncertainties in computer codes used for reactor core thermal hydraulic design. Stress analysis for a 61-pin fuel assembly scaled down from Prototype Generation IV Sodium-cooled Fast Reactor was conducted and structural integrity in terms of load controlled stress limits was conducted. In this study, The evaluations on load-controlled stress limits for a 61-pin test fuel assembly to be used for reactor core subchannel flow distribution tests were conducted assuming that the test assembly is installed in a Prototype Generation IV Sodium-cooled fast reactor core. The 61-pin test assembly has the geometric similarity on P/D and H/D with PGSFR and material of fuel assembly is austenitic stainless steel 316L. The stress analysis results showed that 4.05MPa under primary load occurred at mid part of the test assembly and it was shown that the value of 4.05Mpa was far smaller than the code allowable of 127MPa. , it was shown that the stress intensity due to due to primary load is very small. The stress analysis results under primary and secondary loads showed that maximum stress intensity of 84.08MPa occurred at upper flange tangent to outer casing and the value was well within the code allowable of 268.8MPa. Integrity evaluations based on strain limits and creep-fatigue damage are underway according to the elevated design codes.

  2. Transport hysteresis of core plasma, isotope effect, and H-mode physics

    Science.gov (United States)

    Itoh, S.-I.; Itoh, K.; Inagaki, S.

    2017-02-01

    This article assesses the understanding of and impact by the hysteresis in transport relation. The rapid changes of fluxes compared to slow changes of plasma parameters are overviewed for both edge barrier and core plasmas. The theoretical approaches to understanding the direct influence of heating power on turbulent transport are addressed. Based on this new theoretical framework, the ‘isotope effect’ of plasma confinement time is discussed. A trial explanation is given for this unresolved mystery in plasma confinement. The advanced data analysis method to research the hysteresis in gradient-flux relation is explained.

  3. Plasmonic core-satellite assemblies with high stability and yield (Conference Presentation)

    Science.gov (United States)

    Huang, Li-Ching; Lin, Tien-Hsin; Liu, Zhi-Yan; Chen, Jyun-Hao; Wang, Yi-Chen; Chen, Shiuan-Yeh

    2016-09-01

    Plasmonic structures are attractive due to their optical properties in the near-field and far-field. In the near-field, the enhanced field they generated strongly interacts with materials in proximity to the surface and even produces the quantum hybrid states in the strong coupling regime. In the far-field, the larger scattering cross section of plasmonic particles provides better contrast for tissue imaging. In addition, the strong absorption can generate substantial amount of heat for cancer cell elimination. These optical properties are usually engineered through tuning the size and morphology of individual nanoparticles by various chemical synthesis methods. The alternative way is to use coupled structure based on existing particles. The molecule-linked structure is a common way for 3D plasmonic materials. However, to produce a stable coupled structure in the solution phase is challenging. The formation of linkage between linker molecules is usually time-consuming and at low efficiency. Increasing the concentration of linker molecules may raise the reaction speed but also result in the random aggregation of particles. In this work, a polyelectrolyte coating is used to connect spherical nanoparticles of different sizes to form core-satellite assemblies (CSA). The coupled core-satellite structure is formed almost immediately after the solutions of two particles are mixed. The output efficiency is nearly 100%. The CSA is robust under the additional silica shell coating and strong laser illumination. The stability of this CSA is confirmed by the Raman spectra and this assembly can potentially be used as Raman tags.

  4. Removal plan for Shippingport pressurized water reactor core 2 blanket fuel assemblies form T plant to the canister storage building

    Energy Technology Data Exchange (ETDEWEB)

    Lata

    1996-09-26

    This document presents the current strategy and path forward for removal of the Shippingport Pressurized Water Reactor Core 2 blanket fuel assemblies from their existing storage configuration (wet storage within the T Plant canyon) and transport to the Canister Storage Building (designed and managed by the Spent Nuclear Fuel. Division). The removal plan identifies all processes, equipment, facility interfaces, and documentation (safety, permitting, procedures, etc.) required to facilitate the PWR Core 2 assembly removal (from T Plant), transport (to the Canister storage Building), and storage to the Canister Storage Building. The plan also provides schedules, associated milestones, and cost estimates for all handling activities.

  5. Plasma membrane is the site of productive HIV-1 particle assembly.

    Directory of Open Access Journals (Sweden)

    Nolwenn Jouvenet

    2006-12-01

    Full Text Available Recently proposed models that have gained wide acceptance posit that HIV-1 virion morphogenesis is initiated by targeting the major structural protein (Gag to late endosomal membranes. Thereafter, late endosome-based secretory pathways are thought to deliver Gag or assembled virions to the plasma membrane (PM and extracellular milieu. We present several findings that are inconsistent with this model. Specifically, we demonstrate that HIV-1 Gag is delivered to the PM, and virions are efficiently released into the extracellular medium, when late endosome motility is abolished. Furthermore, we show that HIV-1 virions are efficiently released when assembly is rationally targeted to the PM, but not when targeted to late endosomes. Recently synthesized Gag first accumulates and assembles at the PM, but a proportion is subsequently internalized via endocytosis or phagocytosis, thus accounting for observations of endosomal localization. We conclude that HIV-1 assembly is initiated and completed at the PM, and not at endosomal membranes.

  6. Tuning the Mechanical Properties of Hydrogel Core-Shell Particles by Inwards Interweaving Self-Assembly.

    Science.gov (United States)

    Pan, Houwen Matthew; Seuss, Maximilian; Neubauer, Martin P; Trau, Dieter W; Fery, Andreas

    2016-01-20

    Mechanical properties of hydrogel particles are of importance for their interactions with cells or tissue, apart from their relevance to other applications. While so far the majority of works aiming at tuning particle mechanics relied on chemical cross-linking, we report a novel approach using inwards interweaving self-assembly of poly(allylamine) (PA) and poly(styrenesulfonic acid) (PSSA) on agarose gel beads. Using this technique, shell thicknesses up to tens of micrometers can be achieved from single-polymer incubations and accurately controlled by varying the polymer concentration or incubation period. We quantified the changes in mechanical properties of hydrogel core-shell particles. The effective elastic modulus of core-shell particles was determined from force spectroscopy measurements using the colloidal probe-AFM (CP-AFM) technique. By varying the shell thickness between 10 and 24 μm, the elastic modulus of particles can be tuned in the range of 10-190 kPa and further increased by increasing the layer number. Through fluorescence quantitative measurements, the polymeric shell density was found to increase together with shell thickness and layer number, hence establishing a positive correlation between elastic modulus and shell density of core-shell particles. This is a valuable method for constructing multidensity or single-density shells of tunable thickness and is particularly important in mechanobiology as studies have reported enhanced cellular uptake of particles in the low-kilopascal range (shell particles for the separation of biomolecules or systemic study of stiffness-dependent cellular uptake.

  7. Nonthermal Plasma Synthesis of Core/Shell Quantum Dots: Strained Ge/Si Nanocrystals.

    Science.gov (United States)

    Hunter, Katharine I; Held, Jacob T; Mkhoyan, K Andre; Kortshagen, Uwe R

    2017-03-08

    In this work, we present an all-gas-phase approach for the synthesis of quantum-confined core/shell nanocrystals (NCs) as a promising alternative to traditional solution-based methods. Spherical quantum dots (QDs) are grown using a single-stage flow-through nonthermal plasma, yielding monodisperse NCs, with a concentric core/shell structure confirmed by electron microscopy. The in-flight negative charging of the NCs by plasma electrons keeps the NC cores separated during shell growth. The success of this gas-phase approach is demonstrated here through the study of Ge/Si core/shell QDs. We find that the epitaxial growth of a Si shell on the Ge QD core compressively strains the Ge lattice and affords the ability to manipulate the Ge band structure by modulation of the core and shell dimensions. This all-gas-phase approach to core/shell QD synthesis offers an effective method to produce high-quality heterostructured NCs with control over the core and shell dimensions.

  8. First experimental demonstration of magnetic-field assisted fast heating of a dense plasma core

    Science.gov (United States)

    Fujioka, Shinsuke; Sakata, Shohei; Lee, Seung Ho; Matsuo, Kazuki; Sawada, Hiroshi; Iwasa, Yuki; Law, King Fai Farley; Morita, Hitoki; Kojima, Sadaoki; Abe, Yuki; Yao, Akira; Hata, Masayasu; Johzaki, Tomoyuki; Sunahara, Atsushi; Ozaki, Tetsuo; Sakagami, Hitoshi; Morace, Alessio; Arikawa, Yasunobu; Yogo, Akifumi; Nishimura, Hiroaki; Nakai, Mitsuo; Shiraga, Hiroyuki; Sentoku, Yasuhiko; Nagatomo, Hideo; Azechi, Hiroshi; Firex Project Team

    2016-10-01

    Fast heating of a dense plasma core by an energetic electron beam is being studied on GEKKO-LFEX laser facility. Here, we introduce a laser-driven kilo-tesla external magnetic field to guide the diverging electron beam to the dense plasma core. This involve placing a spherical target in the magnetic field, compressing it with the GEKKO-XII laser beams and then using the LFEX laser beams injected into the dense plasma to generate the electron beam which do the fast heating. Cu-Ka emission is used to visualize transport or heating processes of a dense plasma. X-ray spectrum from a highly ionized Cu ions indicates several keV of the temperature increment induced by the LFEX.

  9. Preparation of Hollow Spherical and Core/shell Structured Powders by Plasma Processing

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Xiaofeng; ZHOU; Kesong; DENG; Changguang; SONG; Jinbing; ZHANG; Jifu; DONG; Shujuan

    2015-01-01

    Four types of hollow spherical micro- and nano-szied powders of ZrO2-7wt.%Y2O3(7YSZ), ZrO2-7wt.%Y2O3, Al2O3-13 wt.% TiO2(AT) and WC as well as one type of core/shell structured powder of ZrB2-30 wt.%Mo Si2 were prepared via plasma processing. In addition, the formation mechanisms of hollow spherical and core/shell structured powders prepared via plasma processing were also proposed.

  10. Characterization of Carbon Particulates in the Exit Flow of a Plasma Pyrolysis Assembly (PPA) Reactor

    Science.gov (United States)

    Green, Robert D.; Meyer, Marit E.; Agui, Juan H.; Berger, Gordon M.; Vijayakumar, R.; Abney, Morgan B.; Greenwood, Zachary

    2015-01-01

    The ISS presently recovers oxygen from crew respiration via a Carbon Dioxide Reduction Assembly (CRA) that utilizes the Sabatier chemical process to reduce captured carbon dioxide to methane (CH4) and water. In order to recover more of the hydrogen from the methane and increase oxygen recovery, NASA Marshall Space Flight Center (MSFC) is investigating a technology, plasma pyrolysis, to convert the methane to acetylene. The Plasma Pyrolysis Assembly (or PPA), achieves 90% or greater conversion efficiency, but a small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. In this work, we present the experimental results of an initial characterization of the carbon particulates in the PPA exit gas stream. We also present several potential options to remove these carbon particulates via carbon traps and filters to minimize resupply mass and required downtime for regeneration.

  11. The use of process plasmas for cleaning PCB substrates for fluxless soldering of electronic assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Philpott, J.D

    1999-12-01

    In this thesis the ability of single and multiple gas plasmas to improve the solderability of PCB substrates, and hence allow the removal of flux from the soldering process for electronic assemblies has been investigated. It has been shown that asymmetric electrode plasma chambers allow the use of single gas plasmas for this purpose due to their greater efficiency compared to symmetric systems. It has also been shown that the use of triple gas plasmas results in improved cleaning ability when using symmetric electrode systems. Dynamic contact angle (DCA) analysis was the primary analytical technique used in this work. This technique produces two contact angles, advancing and receding. The advancing contact angle determines the surface energy of a solid. It has been shown using Auger analysis that contact angles of approximately 48 deg indicate low levels of hydrocarbon contamination. It has also been shown that plasma cleaning processes giving advancing contact angles of this magnitude result in the ability to solder Hot Air Solder Leveled (HASL) PCB substrates without the use of flux. In addition it has been shown that, whilst it is possible to reduce the advancing contact angle of copper substrates considerably, the reduction is not as great as for HASL substrates. Analytical models of RF plasma chambers have also been reviewed, and these adapted for the plasma chambers used in this work. The experimental work carried out in this research also shows that these models hold true. (author)

  12. Rab18 is required for viral assembly of hepatitis C virus through trafficking of the core protein to lipid droplets.

    Science.gov (United States)

    Dansako, Hiromichi; Hiramoto, Hiroki; Ikeda, Masanori; Wakita, Takaji; Kato, Nobuyuki

    2014-08-01

    During persistent infection of HCV, the HCV core protein (HCV-JFH-1 strain of genotype 2a) is recruited to lipid droplets (LDs) for viral assembly, but the mechanism of recruitment of the HCV core protein is uncertain. Here, we demonstrated that one of the Ras-related small GTPases, Rab18, was required for trafficking of the core protein around LDs. The knockdown of Rab18 reduced intracellular and extracellular viral infectivity, but not intracellular viral replication in HCV-JFH-1-infected RSc cells (an HuH-7-derived cell line). Exogenous expression of Rab18 increased extracellular viral infectivity almost two-fold. Furthermore, Rab18 was co-localized with the core protein in HCV-JFH-1-infected RSc cells, and the knockdown of Rab18 blocked recruitment of the HCV-JFH-1 core protein to LDs. These results suggest that Rab18 has an important role in viral assembly through the trafficking of the core protein to LDs.

  13. Bioengineered Vaults: Self-Assembling Protein Shell–Lipophilic Core Nanoparticles for Drug Delivery

    Science.gov (United States)

    2015-01-01

    We report a novel approach to a new class of bioengineered, monodispersed, self-assembling vault nanoparticles consisting of a protein shell exterior with a lipophilic core interior designed for drug and probe delivery. Recombinant vaults were engineered to contain a small amphipathic α-helix derived from the nonstructural protein 5A of hepatitis C virus, thereby creating within the vault lumen a lipophilic microenvironment into which lipophilic compounds could be reversibly encapsulated. Multiple types of electron microscopy showed that attachment of this peptide resulted in larger than expected additional mass internalized within the vault lumen attributable to incorporation of host lipid membrane constituents spanning the vault waist (>35 nm). These bioengineered lipophilic vaults reversibly associate with a sample set of therapeutic compounds, including all-trans retinoic acid, amphotericin B, and bryostatin 1, incorporating hundreds to thousands of drug molecules per vault nanoparticle. Bryostatin 1 is of particular therapeutic interest because of its ability to potently induce expression of latent HIV, thus representing a preclinical lead in efforts to eradicate HIV/AIDS. Vaults loaded with bryostatin 1 released free drug, resulting in activation of HIV from provirus latency in vitro and induction of CD69 biomarker expression following intravenous injection into mice. The ability to preferentially and reversibly encapsulate lipophilic compounds into these novel bioengineered vault nanoparticles greatly advances their potential use as drug delivery systems. PMID:25061969

  14. Nuclear Data Uncertainties for Typical LWR Fuel Assemblies and a Simple Reactor Core

    Science.gov (United States)

    Rochman, D.; Leray, O.; Hursin, M.; Ferroukhi, H.; Vasiliev, A.; Aures, A.; Bostelmann, F.; Zwermann, W.; Cabellos, O.; Diez, C. J.; Dyrda, J.; Garcia-Herranz, N.; Castro, E.; van der Marck, S.; Sjöstrand, H.; Hernandez, A.; Fleming, M.; Sublet, J.-Ch.; Fiorito, L.

    2017-01-01

    The impact of the current nuclear data library covariances such as in ENDF/B-VII.1, JEFF-3.2, JENDL-4.0, SCALE and TENDL, for relevant current reactors is presented in this work. The uncertainties due to nuclear data are calculated for existing PWR and BWR fuel assemblies (with burn-up up to 40 GWd/tHM, followed by 10 years of cooling time) and for a simplified PWR full core model (without burn-up) for quantities such as k∞, macroscopic cross sections, pin power or isotope inventory. In this work, the method of propagation of uncertainties is based on random sampling of nuclear data, either from covariance files or directly from basic parameters. Additionally, possible biases on calculated quantities are investigated such as the self-shielding treatment. Different calculation schemes are used, based on CASMO, SCALE, DRAGON, MCNP or FISPACT-II, thus simulating real-life assignments for technical-support organizations. The outcome of such a study is a comparison of uncertainties with two consequences. One: although this study is not expected to lead to similar results between the involved calculation schemes, it provides an insight on what can happen when calculating uncertainties and allows to give some perspectives on the range of validity on these uncertainties. Two: it allows to dress a picture of the state of the knowledge as of today, using existing nuclear data library covariances and current methods.

  15. Probing charge transfer dynamics in self-assembled monolayers by core hole clock approach

    Energy Technology Data Exchange (ETDEWEB)

    Zharnikov, Michael, E-mail: Michael.Zharnikov@urz.uni-heidelberg.de

    2015-04-15

    This article reviews recent progress in the application of core hole clock approach in the framework of resonant Auger electron spectroscopy to the monomolecular assembles of alkyl, oligophenyl, and oligo(phenylene–ethynylene) based molecules on Au(1 1 1) substrates, referring mostly to the work by the author et al. The major goal was to study electron transfer (ET) dynamics in these systems serving as prototypes of molecular electronics (ME) devices. The ET pathway to the conductive substrate was unambiguously defined by resonant excitation of the nitrile tailgroup attached to the molecular backbone. Characteristic ET times within the femtosecond domain were determined, along with the attenuation factors for the ET dynamics, analogous to the case of the static transport. The above parameters were found to exhibit strong dependence on the character of the molecular orbital which mediates the ET process. In addition, certain spectral features, which can be associated with an inverse ET from the molecular backbone to the excitation site, were observed upon exchange of the nitrile group by strongly electronegative nitro moiety. The reported results represent a valuable input for theory and a certain potential for applications such as ME devices where optimization of ET can have significant technological impact.

  16. Preparation of paclitaxel/chitosan co-assembled core-shell nanofibers for drug-eluting stent

    Science.gov (United States)

    Tang, Jing; Liu, Yongjia; Zhu, Bangshang; Su, Yue; Zhu, Xinyuan

    2017-01-01

    The paclitaxel/chitosan (PTX/CS) core-shell nanofibers (NFs) are easily prepared by co-assembly of PTX and CS and used in drug-eluting stent. The mixture solution of PTX (dissolved in ethanol) and CS (dissolved in 1% acetic acid water solution) under sonication will make the formation of NFs, in which small molecule PTX co-assembles with biomacromolecular CS through non-covalent interactions. The obtained NFs are tens to hundreds nanometers in diameter and millimeter level in length. Furthermore, the structure of PTX/CS NFs was characterized by confocal laser scanning microscopy (CLSM), zeta potential, X-ray photoelectron spectroscopy (XPS) and nanoscale infra-red (nanoIR), which provided evidences demonstrated that PTX/CS NFs are core-shell structures. The 'shell' of CS wrapped outside of the NFs, while PTX is located in the core. Thus it resulted in high drug loading content (>40 wt.%). The well-controlled drug release, low cytotoxicity and good haemocompatibility were also found in drug carrier system of PTX/CS NFs. In addition, the hydrophilic and flexible properties of NFs make them easily coating and filming on stent to prepare drug-eluting stent (DES). Therefore, this study provides a convenient method to prepare high PTX loaded NFs, which is a promising nano-drug carrier used for DES and other biomedical applications. The possible molecular mechanism of PTX and CS co-assembly and core-shell nanofiber formation is also explored.

  17. Continuous ice-core chemical analyses using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    McConnell, Joseph R; Lamorey, Gregg W; Lambert, Steven W; Taylor, Kendrick C

    2002-01-01

    Impurities trapped in ice sheets and glaciers have the potential to provide detailed, high temporal resolution proxy information on paleo-environments, atmospheric circulation, and environmental pollution through the use of chemical, isotopic, and elemental tracers. We present a novel approach to ice-core chemical analyses in which an ice-core melter is coupled directly with both an inductively coupled plasma mass spectrometer and a traditional continuous flow analysis system. We demonstrate this new approach using replicated measurements of ice-core samples from Summit, Greenland. With this method, it is possible to readily obtain continuous, exactly coregistered concentration records for a large number of elements and chemical species at ppb and ppt levels and at unprecedented depth resolution. Such very-high depth resolution, multiparameter measurements will significantly expand the use of ice-core records for environmental proxies.

  18. Giant exchange bias and its angular dependence in Co/CoO core-shell nanowire assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Gandha, Kinjal; Chaudhary, Rakesh P.; Mohapatra, Jeotikanta; Koymen, Ali R.; Liu, J. Ping, E-mail: pliu@uta.edu

    2017-07-12

    The exchange-bias field (H{sub EB}) and its angular dependence are systematically investigated in Co/CoO core-shell nanowire assemblies (∼15 nm in diameter and ∼200 nm in length) consisting of single-crystalline Co core and polycrystalline CoO shell. Giant exchange-bias field (H{sub EB}) up to 2.4 kOe is observed below a blocking temperature (T{sub EB} ∼150 K) in the aligned Co/CoO nanowire assemblies. It is also found that there is an angular dependence between the H{sub EB} and the applied magnetization direction. The H{sub EB} showed a peak at 30° between the applied field and the nanowire aligned direction, which may be attributed to the noncollinear spin orientations at the interface between the ferromagnetic core and the antiferromagnetic shell. This behavior is quantitatively supported by an analytical calculation based on Stoner–Wohlfarth model. This study underlines the importance of the competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. - Highlights: • Giant exchange bias is observed in oriented Co/CoO core-shell nanowire assemblies. • Study of angular and temperature dependence of the exchange bias effect. • Competing magnetic anisotropies at the interface of Co/CoO core-shell nanowires. • Effect of misaligned spins in FM/AFM interface on angular dependence of exchange bias. • We explain the analytical model that accounts for experimental results.

  19. Core Fueling and Edge Particle Flux Analysis in Ohmically and Auxiliary Heated NSTX Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    V.A. Soukhanovskii; R. Maingi; R. Raman; H.W. Kugel; B.P. LeBlanc; L. Roquemore; C.H. Skinner; NSTX Research Team

    2002-06-12

    The Boundary Physics program of the National Spherical Torus Experiment (NSTX) is focusing on optimization of the edge power and particle flows in b * 25% L- and H-mode plasmas of t {approx} 0.8 s duration heated by up to 6 MW of high harmonic fast wave and up to 5 MW of neutral beam injection. Particle balance and core fueling efficiencies of low and high field side gas fueling of L-mode homic and NBI heated plasmas have been compared using an analytical zero dimensional particle balance model and measured ion and neutral fluxes. Gas fueling efficiencies are in the range of 0.05-0.20 and do not depend on discharge magnetic configuration, density or poloidal location of the injector. The particle balance modeling indicates that the addition of HFS fueling results in a reversal of the wall loading rate and higher wall inventories. Initial particle source estimates obtained from neutral pressure and spectroscopic measurements indicate that ion flux into the divertor greatly exceeds midplane ion flux from the main plasma, suggesting that the scrape-off cross-field transport plays a minor role in diverted plasmas. Present analysis provides the basis for detailed fluid modeling of core and edge particle flows and particle confinement properties of NSTX plasmas. This research was supported by the U.S. Department of Energy under contracts No. DE-AC02-76CH03073, DE-AC05-00OR22725, and W-7405-ENG-36.

  20. Soliton-plasma nonlinear dynamics in mid-IR gas-filled hollow-core fibers

    DEFF Research Database (Denmark)

    Habib, Selim; Markos, Christos; Bang, Ole

    2017-01-01

    We investigate numerically soliton-plasma interaction in a noble-gas-filled silica hollow-core anti-resonant fiber pumped in the mid-IR at 3.0 mu m. We observe multiple soliton self-compression stages due to distinct stages where either the self-focusing or the self-defocusing nonlinearity...... dominates. Specifically, the parameters may be tuned so the competing plasma self-defocusing nonlinearity only dominates over the Kerr self-focusing nonlinearity around the soliton self-compression stage, where the increasing peak intensity on the leading pulse edge initiates a competing self...

  1. Fabrication of electrodes with ultralow platinum loading by RF plasma processing of self-assembled arrays of Au@Pt nanoparticles

    Science.gov (United States)

    Banerjee, Ipshita; Kumaran, V.; Santhanam, Venugopal

    2016-07-01

    Conductive, carbon-free, electrocatalytically active, nanostructured electrodes with ultra-low platinum loading were fabricated using self-assembly of octadecanethiol-coated Au@Pt nanoparticles followed by RF plasma treatment. Bilayer arrays of Au@Pt nanoparticles with platinum loadings of 0.50, 1.04, 1.44, and 1.75 μg cm-2 (corresponding to 0.5, 1, 1.5 and 2 atomic layer coverage of platinum on nominally 5 nm gold core) were subjected to RF argon plasma treatment for various durations and their electrical conductivity, morphological evolution, and electrocatalytic activity characterized. Samples with monolayer and above platinum coverages exhibit maximum electrochemically active surface areas values of ˜100 m2/gpt and specific activities that are ˜4× to 6× of a reference platinum nanoparticle bilayer array. The underlying gold core influences the structural evolution of the samples upon RF plasma treatment and leads to the formation of highly active Pt(110) facets on the surface at an optimal plasma treatment duration, which also corresponds to the onset of a sharp decline in lateral sheet resistance. The sample having a two atom thick platinum coating has the highest total mass activity of 48 ± 3 m2/g(pt+au), corresponding to 44% Pt atom utilization, while also exhibiting enhanced CO tolerance as well as high methanol oxidation reaction and oxygen reduction reaction activity.

  2. Plasmas for environmental issues: from hydrogen production to 2D materials assembly

    Science.gov (United States)

    Tatarova, E.; Bundaleska, N.; Sarrette, J. Ph; Ferreira, C. M.

    2014-12-01

    It is well recognized at present that the unique, high energy density plasma environment provides suitable conditions to dissociate/atomize molecules in remediation systems, to convert waste and biomass into sustainable energy sources, to purify water, to assemble nanostructures, etc. The remarkable plasma potential is based on its ability to supply simultaneously high fluxes of charged particles, chemically active molecules, radicals (e.g. O, H, OH), heat, highly energetic photons (UV and extreme UV radiation), and strong electric fields in intrinsic sheath domains. Due to this complexity, low-temperature plasma science and engineering is a huge, highly interdisciplinary field that spans many research disciplines and applications across many areas of our daily life and industrial activities. For this reason, this review deals only with some selected aspects of low-temperature plasma applications for a clean and sustainable environment. It is not intended to be a comprehensive survey, but just to highlight some important works and achievements in specific areas. The selected issues demonstrate the diversity of plasma-based applications associated with clean and sustainable ambiance and also show the unity of the underlying science. Fundamental plasma phenomena/processes/features are the common fibers that pass across all these areas and unify all these applications. Browsing through different topics, we try to emphasize these phenomena/processes/features and their uniqueness in an attempt to build a general overview. The presented survey of recently published works demonstrates that plasma processes show a significant potential as a solution for waste/biomass-to-energy recovery problems. The reforming technologies based on non-thermal plasma treatment of hydrocarbons show promising prospects for the production of hydrogen as a future clean energy carrier. It is also shown that plasmas can provide numerous agents that influence biological activity. The simultaneous

  3. Self-Assembly of Crystalline Structures of Magnetic Core-Shell Nanoparticles for Fabrication of Nanostructured Materials.

    Science.gov (United States)

    Xue, Xiaozheng; Wang, Jianchao; Furlani, Edward P

    2015-10-14

    A theoretical study is presented of the template-assisted formation of crystalline superstructures of magnetic-dielectric core-shell particles. The templates produce highly localized gradient fields and a corresponding magnetic force that guides the assembly with nanoscale precision in particle placement. The process is studied using two distinct and complementary computational models that predict the dynamics and energy of the particles, respectively. Both mono- and polydisperse colloids are studied, and the analysis demonstrates for the first time that although the particles self-assemble into ordered crystalline superstructures, the particle formation is not unique. There is a Brownian motion-induced degeneracy in the process wherein various distinct, energetically comparable crystalline structures can form for a given template geometry. The models predict the formation of hexagonal close packed (HCP) and face centered cubic (FCC) structures as well as mixed phase structures due to in-plane stacking disorders, which is consistent with experimental observations. The polydisperse particle structures are less uniform than the monodisperse particle structures because of the irregular packing of different-sized particles. A comparison of self-assembly using soft- and hard-magnetic templates is also presented, the former being magnetized in a uniform field. This analysis shows that soft-magnetic templates enable an order-of-magnitude more rapid assembly and much higher spatial resolution in particle placement than their hard-magnetic counterparts. The self-assembly method discussed is versatile and broadly applies to arbitrary template geometries and multilayered and multifunctional mono- and polydisperse core-shell particles that have at least one magnetic component. As such, the method holds potential for the bottom-up fabrication of functional nanostructured materials for a broad range of applications. This work provides unprecedented insight into the assembly

  4. Three-dimensional antenna coupling to core plasma in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.D.; Jaeger, E.F.; Stallings, D.C.; Galambos, J.D.; Batchelor, D.B.; Wang, C.Y.

    1995-09-01

    A complete understanding of the RF physics from the launcher to the plasma core is required to fully analyze RF experiments and to evaluate the performance of RF antenna designs in ITER. This understanding requires a consistent model for the RF power launching system, propagation and absorption through the edge region, and the response of the core plasma to the RF power. As a first step toward such a model, the three-dimensional (3D) antenna modeling code, RANT3D, has been coupled with the reduced order full wave code, PICES. Preliminary results from this model are presented in this paper for parameters similar to those found in the DIII-D experiment.

  5. Three-Dimensional Self-Assembly of Core/Shell-Like Nanostructures for High-Performance Nanocomposite Permanent Magnets.

    Science.gov (United States)

    Li, Hailing; Li, Xiaohong; Guo, Defeng; Lou, Li; Li, Wei; Zhang, Xiangyi

    2016-09-14

    Core/shell nanostructures are fascinating for many advanced applications including strong permanent magnets, magnetic recording, and biotechnology. They are generally achieved via chemical approaches, but these techniques limit them to nanoparticles. Here, we describe a three-dimensional (3D) self-assembly of core/shell-like nanocomposite magnets, with hard-magnetic Nd2Fe14B core of ∼45 nm and soft-magnetic α-Fe shell of ∼13 nm, through a physical route. The resulting Nd2Fe14B/α-Fe core/shell-like nanostructure allows both large remanent magnetization and high coercivity, leading to a record-high energy product of 25 MGOe which reaches the theoretical limit for isotropic Nd2Fe14B/α-Fe nanocomposite magnets. Our approach is based on a sequential growth of the core and shell nanocrystals in an alloy melt. These results make an important step toward fabricating core/shell-like nanostructure in 3D materials.

  6. Core/shell silicon/polyaniline particles via in-flight plasma-induced polymerization

    Science.gov (United States)

    Yasar-Inceoglu, Ozgul; Zhong, Lanlan; Mangolini, Lorenzo

    2015-08-01

    Although silicon nanoparticles have potential applications in many relevant fields, there is often the need for post-processing steps to tune the property of the nanomaterial and to optimize it for targeted applications. In particular surface modification is generally necessary to both tune dispersibility of the particles in desired solvents to achieve optimal coating conditions, and to interface the particles with other materials to realize functional heterostructures. In this contribution we discuss the realization of core/shell silicon/polymer nanoparticles realized using a plasma-initiated in-flight polymerization process. Silicon particles are produced in a non-thermal plasma reactor using silane as a precursor. After synthesis they are aerodynamically injected into a second plasma reactor into which aniline vapor is introduced. The second plasma initiates the polymerization reactor leading to the formation of a 3-4 nm thick polymer shell surrounding the silicon core. The role of processing conditions on the properties of the polymeric shell is discussed. Preliminary results on the testing of this material as an anode for lithium ion batteries are presented.

  7. Self-assembly of human plasma fibrinogens on binary organosilane monolayers with micro domains

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H. [Faculty of Engineering, Shinshu Universuty, 4-17-1 Wakasato, Nagano 380 8553 (Japan); Saito, N., E-mail: hiro@eco-t.esi.nagoya-u.ac.jp [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464 8603 (Japan); Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464 8603 (Japan); Takai, O. [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa, Nagoya 464 8603 (Japan)

    2009-06-30

    The adsorption behavior and self-assembly of human plasma fibrinogen (HPF) on binary methyl- and amino-terminated self-assembled monolayers (SAMs) were investigated by atomic force microscopy (AFM). The binary SAMs were fabricated through self-assembly mechanism of organosilane molecules. The height of domains is the domain height is 0.8 {+-} 0.2 nm from the AFM topographic image. It corresponds to the domain height is 0.8 {+-} 0.2 nm from the AFM topographic image. It corresponds to the difference between the length of the alkyl chain of octadecyltrichlorosilane (OTS) and that of n-(6-aminohexyl)aminopropyltrimethoxysilane (AHAPS). The fibrinogen solution used ultrapure water as the solvent and its pH was adjusted at 3 and 10. From the AFM results at pH 3, HPF only formed network structures on the OTS domains of the binary SAM at early immersion times, and then the network structures expanded and connected between OTS domains through the AHAPS surface at long immersion times. In this case, a few HPFs are discretely adsorbed on the AHAPS surface. However, HPF is uniformly adsorbed on the binary SAM under the other conditions of pH.

  8. Core Radial Electric Field and Transport in Wendelstein 7-X Plasmas

    Science.gov (United States)

    Pablant, Novimir

    2016-10-01

    Results from the investigation of core transport and the role of the radial electric field profile (Er) in the first operational phase of the Wendelstein 7-X (W7-X) stellarator are presented. In stellarator plasmas, the details of the Er profile are expected to have a strong effect on both the particle and heat fluxes. Neoclassical particle fluxes are not intrinsically ambipolar, which leads to the formation of a radial electric field that enforces ambipolarity. The radial electric field is closely related to the perpendicular plasma flow (u⊥) through the force balance equation. This allows the radial electric field to be inferred from measurements of the perpendicular flow velocity from the x-ray imaging crystal spectrometer (XICS) and correlation reflectometry diagnostics. Large changes in the perpendicular rotation, on the order of Δu⊥ 5km /s (ΔEr 12kV / m), have been observed within a set of experiments where the heating power was stepped down from 2 MW to 0.6 MW . These experiments are examined in detail to explore the relationship between, heating power, response of the temperature and density profiles and the response of the radial electric field. Estimations of the core transport are based on power balance and utilize electron temperature (Te) profiles from the ECE and Thomson scattering, electron density profiles (ne) from interferometry and Thomson scattering, ion temperature (Ti) profiles from XICS, along with measurements of the total stored energy and radiated power. Also described are a set core impurity confinement experiments and results. Impurity confinement has been investigated through the injection of trace amount of argon impurity gas at the plasma edge in conjunction with measurements of the density of various ionization states of argon from the XICS and High Efficiency eXtreme-UV Overview Spectrometer (HEXOS) diagnostics. Finally the inferred Er and heat flux profiles are compared to initial neoclassical calculations using measured

  9. Dynamics of laser-imploded core plasmas observed by ultrafast two-dimensional x-ray imaging with animation display

    Energy Technology Data Exchange (ETDEWEB)

    Heya, Manabu; Shiraga, Hiroyuki; Shimada, Kyoko; Miyanaga, Noriaki; Takabe, Hideaki; Yamanaka, Tatsuhiko; Mima, Kunioki [Osaka Univ., Inst. of Laser Engineering, Suita, Osaka (Japan)

    1999-05-01

    In order to observe time-resolved, two-dimensional (2D) spatial distribution of x rays emitted from core plasmas at the final stage of the implosion, we have developed a multi-imaging x-ray streak camera (MIXS) and a multi-channel MIXS (McMIXS) methods as new ultrafast 2D x-ray imaging techniques. The observed time-resolved 2D x-ray and electron-temperature images of core plasmas, which are sequentially changing with time, have been displayed by using an animation method. Temporal evolutions of nonuniform structures, including shape, size, and movement of core plasmas can be observed instinctively with the animated display. The ultrafast 2D x-ray imaging with the animation display is a new powerful tool for understanding the dynamics of laser-imploded core plasmas. (author)

  10. Control of core argon impurity profile by ECH in KSTAR L-mode plasmas

    Science.gov (United States)

    Hong, Joohwan; Lee, Seung Hun; Kim, Juhyung; Seon, C. R.; Lee, S. G.; Park, G. Y.; Lee, K. D.; Henderson, S. S.; Lee, H. Y.; Park, Jae Sun; Jang, Juhyeok; Jang, Siwon; Jeon, Taemin; O'Mullane, M.; Choe, Wonho

    2015-06-01

    Experiments on trace argon impurity transport in L-mode discharges were performed on Korea superconducting tokamak advanced research (KSTAR) with electron cyclotron resonance heating (ECH). Ar emission was measured by soft x-ray (SXR) arrays and vacuum UV (VUV) diagnostics. A significant reduction in the core Ar emissivity was observed with core ECH. The reduction was the largest with on-axis heating and became smaller with outward heating positions. The diffusivity and convection velocity of Ar were obtained by analysis of the SXR data with the SANCO impurity transport code for the on-axis ECH and the non-ECH shots. In the on-axis ECH case, both diffusivity and convection velocity increased. Furthermore, the convection changed its direction from inward to outward in the plasma core (r/a < 0.3), resulting in a hollow profile of the total Ar density. Together with the reduction in the SXR signals, the hollow impurity profile in the core and the reversal of the convection velocity consistently confirm that ECH can reduce impurity accumulation in the core region. Neoclassical impurity transport and linear stability of micro-turbulence were calculated and discussed in relation to the possible transport mechanism.

  11. Coupled core-SOL modelling of W contamination in H-mode JET plasmas with ITER-like wall

    Energy Technology Data Exchange (ETDEWEB)

    Parail, V., E-mail: Vassili.parail@ccfe.ac.uk [CCFE Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Corrigan, G.; Da Silva Aresta Belo, P. [CCFE Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); De La Luna, E. [Laboratorio Nacional de Fusion, Madrid (Spain); Harting, D. [CCFE Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Koechl, F. [Atominstitut, TU Wien, 1020 Vienna (Austria); Koskela, T. [Aalto University, Department of Applied Physics, P.O. Box 14100, FIN-00076 Aalto (Finland); Meigs, A.; Militello-Asp, E.; Romanelli, M. [CCFE Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Tsalas, M. [FOM Institute DIFFER, P.O. Box 1207, NL-3430 BE Nieuwegein (Netherlands)

    2015-08-15

    The influence of the ITER-like Wall (ILW) with divertor target plate made of tungsten (W), on plasma performance in JET H-mode is being investigated since 2011 (see F. Romanelli and references therein). One of the key issues in discharges with low level of D fuelling is observed accumulation of W in the plasma core, which leads to a reduction in plasma performance. To study the interplay between W sputtering on the target plate, penetration of W through the SOL and edge transport barrier (ETB) and its further accumulation in plasma core predictive modelling was launched using a coupled 1.5D core and 2D SOL code JINTRAC (Romanelli, 2014; Cenacchi and Taroni, 1988; Taroni et al., 1992; Wiesen et al., 2006). Simulations reveal the important role of ELMs in W sputtering and plasma density control. Analyses also confirm pivotal role played by the neo-classical pinch of heavy impurities within the ETB.

  12. Controlled-release and preserved bioactivity of proteins from (self-assembled core-shell double-walled microspheres

    Directory of Open Access Journals (Sweden)

    Yuan W

    2012-01-01

    Full Text Available Weien Yuan1,2, Zhenguo Liu11Department of Neurology, Xinhua Hospital, affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of ChinaAbstract: In order to address preserved protein bioactivities and protein sustained-release problems, a method for preparing double-walled microspheres with a core (protein-loaded nanoparticles with a polymer-suspended granule system-formed core and a second shell (a polymer-formed shell for controlled drug release and preserved protein bioactivities has been developed using (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W phases. The method, based on our previous microsphere preparation method (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W, employs different concentric poly(D,L-lactide-co-glycolide, poly(D,L-lactide, and protein-loaded nanoparticles to produce a suspended liquid which then self-assembles to form shell-core microspheres in the hydrophilic oil phase, which are then solidified in the water phase. Variations in the preparation parameters allowed complete encapsulation by the shell phase, including the efficient formation of a poly(D,L-lactide shell encapsulating a protein-loaded nanoparticle-based poly(D,L-lactide-co-glycolide core. This method produces core-shell double-walled microspheres that show controlled protein release and preserved protein bioactivities for 60 days. Based upon these results, we concluded that the core-shell double-walled microspheres might be applied for tissue engineering and therapy for chronic diseases, etc.Keywords: protein delivery, protein stability, core-shell microspheres, dextran nanoparticles

  13. Plasma-wall interaction data needs critical to a Burning Core Experiment (BCX)

    Energy Technology Data Exchange (ETDEWEB)

    1985-11-01

    The Division of Development and Technology has sponsored a four day US-Japan workshop ''Plasma-Wall Interaction Data Needs Critical to a Burning Core Experiment (BCX)'', held at Sandia National Laboratories, Livermore, California on June 24 to 27, 1985. The workshop, which brought together fifty scientists and engineers from the United States, Japan, Germany, and Canada, considered the plasma-material interaction and high heat flux (PMI/HHF) issues for the next generation of magnetic fusion energy devices, the Burning Core Experiment (BCX). Materials options were ranked, and a strategy for future PMI/HHF research was formulated. The foundation for international collaboration and coordination of this research was also established. This volume contains the last three of the five technical sessions. The first of the three is on plasma materials interaction issues, the second is on research facilities and the third is from smaller working group meetings on graphite, beryllium, advanced materials and future collaborations.

  14. Encapsulation and controlled release from core-shell nanoparticles fabricated by plasma polymerization

    Science.gov (United States)

    Shahravan, Anaram; Matsoukas, Themis

    2012-01-01

    Core-shell nanostructures have been synthesized by plasma deposition in radio-frequency plasma reactor. Silica and KCl nanoparticles were encapsulated by deposition of isopropanol-based films of amorphous hydrogenated carbon. Through control of the deposition time, under constant deposition rate of 1 nm/min, particles are encapsulated in a layer of plasma polymer with thickness between 15 and 100 nm. Films are robust, chemically inert, thermally stable up to 250°C. The permeability of the shells is determined by depositing films of various thickness onto KCl nanoparticles and monitoring the dissolution of the core in aqueous solution. The dissolution profile is characterized by an initial rapid release, followed by a slow release that lasts up to 30 days for the thickest films. The profile is analyzed by Fickian diffusion through a spherical matrix. We find that this model captures very accurately the entire release profile except for the first 12 hours during which, the dissolution rate is higher than that predicted by the model. The overall diffusion coefficient for the dissolution of KCl is 3 × 10-21 m2/s.

  15. Operational Status of the International Space Station Plasma Contactor Hollow Cathode Assemblies July 2001 to May 2013

    Science.gov (United States)

    Kamhawi, Hani; Yim, John T.; Patterson, Michael J.; Dalton, Penni J.

    2013-01-01

    The International Space Station has onboard two Aerojet Rocketdyne developed plasma contactor units that perform the function of charge control. The plasma contactor units contain NASA Glenn Research Center developed hollow cathode assemblies. NASA Glenn Research Center monitors the on-orbit operation of the flight hollow cathode assemblies. As of May 31, 2013, HCA.001-F has been ignited and operated 123 times and has accumulated 8072 hours of operation, whereas, HCA.003-F has been ignited and operated 112 times and has accumulated 9664 hours of operation. Monitored hollow cathode ignition times and anode voltage magnitudes indicate that they continue to operate nominally.

  16. Operational Status of the International Space Station Plasma Contactor Hollow Cathode Assemblies from July 2011 to May 2013

    Science.gov (United States)

    Kamhawi, Hani; Yim, John T.; Patterson, Michael J.; Dalton, Penni J.

    2014-01-01

    The International Space Station has onboard two Aerojet Rocketdyne developed plasma contactor units that perform the function of charge control. The plasma contactor units contain NASA Glenn Research Center developed hollow cathode assemblies. NASA Glenn Research Center monitors the onorbit operation of the flight hollow cathode assemblies. As of May 31, 2013, HCA.001-F has been ignited and operated 123 times and has accumulated 8072 hours of operation, whereas, HCA.003-F has been ignited and operated 112 times and has accumulated 9664 hours of operation. Monitored hollow cathode ignition times and anode voltage magnitudes indicate that they continue to operate nominally.

  17. Self-assembled HCV core virus-like particles targeted and inhibited tumor cell migration and invasion

    Science.gov (United States)

    Li, Xiang; Xu, Xuehe; Jin, Aihui; Jia, Qunying; Zhou, Huaibin; Kang, Shuai; Lou, Yongliang; Gao, Jimin; Lu, Jianxin

    2013-09-01

    We used a baculovirus expression system to express fusion proteins of HCV core, RGD (Arg-Gly-Asp) peptide, and IFN-α2a fragments in Sf9 cells. Western blotting and electron microscopy demonstrate that HCV core, peptides RGD, and IFN-α2a fusion proteins assemble into 30 to 40 nm nano-particles (virus-like particles, VLPs). Xenograft assays show that VLPs greatly reduced tumor volume and weight with regard to a nontreated xenograft. Migration and invasion results show that VLPs can inhibit the migration and invasion of the breast cancer cells MDA-MB231. This study will provide theoretical and experimental basis for the establishment of safe and effective tumor-targeted drug delivery systems and clinical application of VLPs carrying cell interacting cargo.

  18. Calculations of 3D full-scale VVER fuel assembly and core models using MCU and BIPR-7A codes

    Energy Technology Data Exchange (ETDEWEB)

    Aleshin, Sergey S.; Bikeev, Artem S.; Bolshagin, Sergey N.; Kalugin, Mikhail A.; Kosourov, Evgeniy K.; Pavlovichev, Aleksandr M.; Pryanichnikov, Aleksandr V.; Sukhino-Khomenko, Evgenia A.; Shcherenko, Anna I.; Shcherenko, Anastasia I.; Shkarovskiy, Denis A. [Nuclear Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

    2015-09-15

    Two types of calculations were made to compare BIPR-7A and MCU results for 3D full-scale models. First EPS (emergency protection system) efficiency and in-core power distributions were analyzed for an equilibrium fuel load of VVER-1000 assuming its operation within an 18-month cycle. Computations were performed without feedbacks and with fuel burnup distributed over the core. After 3D infinite lattices of full-scale VVER-1000 fuel assemblies (A's) with uranium fuel 4.4% enrichment and uranium-erbium fuel 4.4% enrichment and Er{sub 2}O{sub 3} 1 % wt were considered. Computations were performed with feedbacks and fuel burnup at the constant power level. For different time moments effective multiplication factor and power distribution were obtained. EPS efficiency and reactivity effects at chosen time moments were analyzed.

  19. Plasma current start-up experiments without a central solenoid in the iron core STOR-M tokamak

    Science.gov (United States)

    Mitarai, O.; Tomney, G.; Rohollohi, A.; Lewis, E.; McColl, D.; Xiao, C.; Hirose, A.

    2015-06-01

    Reproducible plasma current start-up without a central solenoid (CS) has been demonstrated using the outer ohmic heating (OH) coils in the iron core STOR-M tokamak (Mitarai et al 2014 Fusion Eng. Des. 89 2467-71). Although the outer OH coil current saturates the iron core eventually, it has been demonstrated that the plasma current can be maintained during the iron core saturation phase. In this work, further studies have been conducted to investigate the effects of the turn number of the outer OH coils (N = 4 or N = 6) in the CS-less discharges and to evaluate the plasma stability with respect to the n-decay index of the vertical magnetic field. For the loose coupling of the iron core with N = 4 turns, the plasma current can be sustained after the additional third capacitor bank is applied near the iron core saturation phase, showing the slow transition from the unsaturated to the partially saturated phase. For the case of stronger coupling of N = 6 turns, the plasma current is increased at the same fast bank voltage, but the main discharge is shortened from 35 to 20 ms. As the magnetizing current is smaller due to stronger coupling between the OH coils and the plasma current, the transition from the unsaturated to the saturated phase is slightly difficult at present. The present experimental results suggest a feasible operation scenario in a future spherical tokamak (ST) at least using loose iron core coupling for smoother transition from the unsaturated to the saturated iron core phase. Thus, a reliable plasma current start-up by the outer OH coils and the current ramp-up to a steady state by additional heating power and vertical field coils could be considered as an operation scenario for future ST reactors with an iron core transformer.

  20. Electrically conductive properties of Ag/Si composite nanoparticle assembled films prepared with a plasma-gas-condensation cluster source

    Science.gov (United States)

    Kurokawa, Yuichiro; Hihara, Takehiko

    2014-11-01

    Ag1-x/Six composite nanoparticle assembled films were prepared using a plasma-gas-condensation cluster beam deposition apparatus. The electrical conductivity σ and Hall coefficient |RH| of Ag1-x/Six nanoparticle assembled films obey a power law of the volume fraction of Ag pAg. The marked change at around pAg = pc indicates that the percolation of Ag nanoparticles takes place at the threshold value pc. Moreover, we found that the |RH| at T = 5 K of the Ag1-x/Six nanoparticle assembled film with the closest pAg to pc is 20 times higher than that of the bulk Ag.

  1. Turbulent momentum transport in core tokamak plasmas and penetration of scrape-off layer flows

    Science.gov (United States)

    Abiteboul, J.; Ghendrih, Ph; Grandgirard, V.; Cartier-Michaud, T.; Dif-Pradalier, G.; Garbet, X.; Latu, G.; Passeron, C.; Sarazin, Y.; Strugarek, A.; Thomine, O.; Zarzoso, D.

    2013-07-01

    The turbulent transport of toroidal angular momentum in the core of a tokamak plasma is investigated in global, full-f gyrokinetic simulations, performed with the GYSELA code in the flux-driven regime. During the initial turbulent phase, a front of positive Reynolds stress propagates radially, generating intrinsic toroidal rotation from a vanishing initial profile. This is also accompanied by a propagating front of turbulent heat flux. In the statistical steady-state regime, turbulent transport exhibits large-scale avalanche-like events which are found to transport both heat and momentum, and similar statistical properties are obtained for both fluxes. The impact of scrape-off layer flows is also investigated by modifying the boundary conditions in the simulations. The observed impact is radially localized for L-mode like poloidal profiles of parallel velocity at the edge, while a constant velocity at the edge can modify the core toroidal rotation profile in a large fraction of the radial domain.

  2. SXR-XUV Diagnostics for Edge and Core of Magnetically Confined Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stutman, Dan [Johns Hopkins University

    2014-09-10

    The present report summarizes the results obtained during a one-year extension of DoE grant “SXR-XUV Diagnostics for Edge and Core of Magnetically Confined Plasmas”, at Johns Hopkins University, aimed at completing the development of a new type of magnetic fusion plasma diagnostic, the XUV Transmission Grating Imaging Radiometer (TGIR). The TGIR enables simultaneous spatially and spectrally resolved measurements of the XUV/VUV radiated power from impurities in fusion plasmas, with high speed. The instrument was successfully developed and qualified in the laboratory and in experiments on a tokamak. Its future applications will be diagnostic of the impurity content and transport in the divertor and edge of advanced magnetic fusion experiments, such as NSTX Upgrade.

  3. Structural studies show energy transfer within stabilized phycobilisomes independent of the mode of rod-core assembly.

    Science.gov (United States)

    David, Liron; Prado, Mindy; Arteni, Ana A; Elmlund, Dominika A; Blankenship, Robert E; Adir, Noam

    2014-03-01

    The major light harvesting complex in cyanobacteria and red algae is the phycobilisome (PBS), comprised of hundreds of seemingly similar chromophores, which are protein bound and assembled in a fashion that enables highly efficient uni-directional energy transfer to reaction centers. The PBS is comprised of a core containing 2-5 cylinders surrounded by 6-8 rods, and a number of models have been proposed describing the PBS structure. One of the most critical steps in the functionality of the PBS is energy transfer from the rod substructures to the core substructure. In this study we compare the structural and functional characteristics of high-phosphate stabilized PBS (the standard fashion of stabilization of isolated complexes) with cross-linked PBS in low ionic strength buffer from two cyanobacterial species, Thermosynechococcus vulcanus and Acaryochloris marina. We show that chemical cross-linking preserves efficient energy transfer from the phycocyanin containing rods to the allophycocyanin containing cores with fluorescent emission from the terminal emitters. However, this energy transfer is shown to exist in PBS complexes of different structures as characterized by determination of a 2.4Å structure by X-ray crystallography, single crystal confocal microscopy, mass spectrometry and transmission electron microscopy of negatively stained and cryogenically preserved complexes. We conclude that the PBS has intrinsic structural properties that enable efficient energy transfer from rod substructures to the core substructures without requiring a single unique structure. We discuss the significance of our observations on the functionality of the PBS in vivo.

  4. Uncertainty analysis for the assembly and core simulation of BEAVRS at the HZP conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Chenghui [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Cao, Liangzhi, E-mail: caolz@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Wu, Hongchun [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Shen, Wei [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Canadian Nuclear Safety Commission, Ottawa, Ontario (Canada)

    2017-04-15

    Highlights: • Uncertainty analysis has been completed based on the “two-step” scheme. • Uncertainty analysis has been performed to BEAVRS at HZP. • For lattice calculations, the few-group constant’s uncertainty was quantified. • For core simulation, uncertainties of k{sub eff} and power distributions were quantified. - Abstract: Based on the “two-step” scheme for the reactor-physics calculations, the capability of uncertainty analysis for the core simulations has been implemented in the UNICORN code, an in-house code for the sensitivity and uncertainty analysis of the reactor-physics calculations. Applying the statistical sampling method, the nuclear-data uncertainties can be propagated to the important predictions of the core simulations. The uncertainties of the few-group constants introduced by the uncertainties of the multigroup microscopic cross sections are quantified first for the lattice calculations; the uncertainties of the few-group constants are then propagated to the core multiplication factor and core power distributions for the core simulations. Up to now, our in-house lattice code NECP-CACTI and the neutron-diffusion solver NECP-VIOLET have been implemented in UNICORN for the steady-state core simulations based on the “two-step” scheme. With NECP-CACTI and NECP-VIOLET, the modeling and simulation of the steady-state BEAVRS benchmark problem at the HZP conditions was performed, and the results were compared with those obtained by CASMO-4E. Based on the modeling and simulation, the UNICORN code has been applied to perform the uncertainty analysis for BAEVRS at HZP. The uncertainty results of the eigenvalues and two-group constants for the lattice calculations and the multiplication factor and the power distributions for the steady-state core simulations are obtained and analyzed in detail.

  5. Electron-ion relaxation in a dense plasma. [supernovae core physics

    Science.gov (United States)

    Littleton, J. E.; Buchler, J.-R.

    1974-01-01

    The microscopic physics of the thermonuclear runaway in highly degenerate carbon-oxygen cores is investigated to determine if and how a detonation wave is generated. An expression for the electron-ion relaxation time is derived under the assumption of large degeneracy and extreme relativity of the electrons in a two-temperature plasma. Since the nuclear burning time proves to be several orders of magnitude shorter than the relaxation time, it is concluded that in studying the structure of the detonation wave the electrons and ions must be treated as separate fluids.

  6. Self-assembled monolayers of perfluoroalkylsilane on plasma-hydroxylated silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lin; Cai, Lu; Liu, Anqi; Wang, Wei; Yuan, Yanhua [College of Textile, Clothing Engineering, Soochow University, Suzhou 215021 (China); National Engineering Laboratory for Modern Silk, Suzhou 215123 (China); Li, Zhanxiong, E-mail: lizhanxiong@suda.edu.cn [College of Textile, Clothing Engineering, Soochow University, Suzhou 215021 (China); State Key Laboratory of Disaster Prevention & Mitigation of Explosion & Impact, Nanjing 210007 (China)

    2015-09-15

    Highlights: • A novel kind of fluoroalkylsilane monomers with different fluoroalkyl chain length was synthesized. • The fluoroalkyl-terminated self-assembled monolayers (SAMs) on silanol-terminated silicon substrates were chemically fabricated using the liquid phase deposition method. • Fluoroalkylsilanes were used for the self-assembly rather than the silane coupling agents and fluorochemicals to fabricate controllable, ordered SAMs. • The angle-dependent XPS study was conducted to investigate the changes of surface structures as well as elemental compositions of the SAMs. • The results indicated that fluoroalkyl groups would migrate from the inner part of the monolayers to the outermost interface after heat treatment, resulting into the microphase separation of the SAMs surface. - Abstract: In this study, a novel kind of fluoroalkylsilane monomers with different fluoroalkyl chain lengths was synthesized via three steps method and characterized by Fourier transform infrared (FT-IR) spectroscopy, {sup 1}H and {sup 19}F nuclear magnetic resonance ({sup 1}H NMR and {sup 19}F NMR), and mass spectra (MS). Fluoroalkyl-terminated self-assembled monolayers (SAMs) on silanol-terminated silicon substrates (O{sub 2} plasma treatment) were chemically fabricated via –Si–O– covalent bonds using the liquid phase deposition method (LPD). The wetabilities of the SAMs were characterized by water contact angles (CA), surface free energies and adhesive force (AF) measurements. 3-(1H,1H,2H,2H-perfluorooctyloxycarbonyl) -propionamidepropyl-triethoxysilane (PFOPT) assembled monolayer was chosen for in-depth investigation as its CA was higher than the others. Attenuated total reflection infrared spectroscopy (ATR-IR) and X-ray photoelectron spectroscopy (XPS) were used to validate the attachment of PFOPT on the silicon substrate, together with the chemical composition and structure of the SAMs. The surface morphologies and roughness of the monolayers were obtained and

  7. A Kinetic Vlasov Model for Plasma Simulation Using Discontinuous Galerkin Method on Many-Core Architectures

    Science.gov (United States)

    Reddell, Noah

    Advances are reported in the three pillars of computational science achieving a new capability for understanding dynamic plasma phenomena outside of local thermodynamic equilibrium. A continuum kinetic model for plasma based on the Vlasov-Maxwell system for multiple particle species is developed. Consideration is added for boundary conditions in a truncated velocity domain and supporting wall interactions. A scheme to scale the velocity domain for multiple particle species with different temperatures and particle mass while sharing one computational mesh is described. A method for assessing the degree to which the kinetic solution differs from a Maxwell-Boltzmann distribution is introduced and tested on a thoroughly studied test case. The discontinuous Galerkin numerical method is extended for efficient solution of hyperbolic conservation laws in five or more particle phase-space dimensions using tensor-product hypercube elements with arbitrary polynomial order. A scheme for velocity moment integration is integrated as required for coupling between the plasma species and electromagnetic waves. A new high performance simulation code WARPM is developed to efficiently implement the model and numerical method on emerging many-core supercomputing architectures. WARPM uses the OpenCL programming model for computational kernels and task parallelism to overlap computation with communication. WARPM single-node performance and parallel scaling efficiency are analyzed with bottlenecks identified guiding future directions for the implementation. The plasma modeling capability is validated against physical problems with analytic solutions and well established benchmark problems.

  8. Observation of asymmetrically imploded core plasmas with a two-dimensional sampling image x-ray streak camera.

    Science.gov (United States)

    Shiraga, Hiroyuki; Lee, Myongdok; Mahigashi, Norimitsu; Fujioka, Shinsuke; Azechi, Hiroshi

    2008-10-01

    A shell target with a cone for guiding the heating beam has been proposed for the fast ignition scheme. Implosion of such target is no longer symmetric because of the cone. A fast two-dimensional x-ray imaging technique, two-dimensional (2D) sampling image x-ray streak camera was applied for the first time to observation of the dynamics of implosion and core plasma. X-ray emission image of the plasma was sampled with two-dimensionally distributed image sampling points, streaked with the tube, and the recorded signals were reconstructed as sequential 2D frame images. Shape and movement of the core plasma were clearly observed.

  9. Hydrogen-plasma-induced magnetocrystalline anisotropy ordering in self-assembled magnetic nanoparticle monolayers.

    Science.gov (United States)

    Weddemann, Alexander; Meyer, Judith; Regtmeier, Anna; Janzen, Irina; Akemeier, Dieter; Hütten, Andreas

    2013-01-01

    Self-assembled two-dimensional arrays of either 14 nm hcp-Co or 6 nm ε-Co particle components were treated by hydrogen plasma for various exposure times. A change of hysteretic sample behavior depending on the treatment duration is reported, which can be divided in two time scales: oxygen reduction increases the particle magnetization during the first 20 min, which is followed by an alteration of the magnetic response shape. The latter depends on the respective particle species. Based on the Landau-Lifshitz equations for a discrete set of magnetic moments, we propose a model that relates the change of the hysteresis loops to a dipole-driven ordering of the magnetocrystalline easy axes within the particle plane due to the high spatial aspect ratio of the system.

  10. Hydrogen-plasma-induced magnetocrystalline anisotropy ordering in self-assembled magnetic nanoparticle monolayers

    Directory of Open Access Journals (Sweden)

    Alexander Weddemann

    2013-03-01

    Full Text Available Self-assembled two-dimensional arrays of either 14 nm hcp-Co or 6 nm ε-Co particle components were treated by hydrogen plasma for various exposure times. A change of hysteretic sample behavior depending on the treatment duration is reported, which can be divided in two time scales: oxygen reduction increases the particle magnetization during the first 20 min, which is followed by an alteration of the magnetic response shape. The latter depends on the respective particle species. Based on the Landau–Lifshitz equations for a discrete set of magnetic moments, we propose a model that relates the change of the hysteresis loops to a dipole-driven ordering of the magnetocrystalline easy axes within the particle plane due to the high spatial aspect ratio of the system.

  11. Analysis of partial and total flow blockage of a single fuel assembly of an MTR research reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Adorni, Martina [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Facolta di Ingegneria, Universita di Pisa, Via Diotisalvi, 2-56100 Pisa (Italy)]. E-mail: martina_adorni@tin.it; Bousbia-Salah, Anis [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Facolta di Ingegneria, Universita di Pisa, Via Diotisalvi, 2-56100 Pisa (Italy); Hamidouche, Tewfik [Commissariat a l' Energie Atomique, Centre de Recherche Nucleaire d' Alger-Algeria, 02 Boulevard Frantz fanon, BP 399 Alger-gare (Algeria); Maro, Beniamino Di [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Facolta di Ingegneria, Universita di Pisa, Via Diotisalvi, 2-56100 Pisa (Italy); Pierro, Franco [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Facolta di Ingegneria, Universita di Pisa, Via Diotisalvi, 2-56100 Pisa (Italy); D' Auria, Francesco [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Facolta di Ingegneria, Universita di Pisa, Via Diotisalvi, 2-56100 Pisa (Italy)

    2005-10-15

    The main aim of the following study is to perform a safety analysis of the IAEA 10 MW MTR Pool type Research Reactor [IAEA-TECDOC-233, 1980. IAEA Research Reactor Core Conversion from the use of high-enriched uranium to the use of low enriched uranium fuels Guidebook] under flow blockage of a single Fuel Assembly (FA) conditions. Such event was rarely investigated in the open literature notwithstanding the fat that it constitutes a severe accident that may lead to local dryout and eventually to loss of the FA integrity. The transients herein considered are related to partial and total obstruction of the cooling channel of a single Fuel Assembly of the reactor core. This study constitutes the first step of a larger work, which consists in performing a 3D simulation using the Best Estimate coupled code technique. However, as a first approach the instantaneous reactor power is derived through the point kinetic approach of the used thermal-hydraulic system code.

  12. Construction of Plasmonic Core-Satellite Nanostructures on Substrates Based on DNA-Directed Self-Assembly as a Sensitive and Reproducible Biosensor.

    Science.gov (United States)

    Zhang, Tingting; Li, He; Hou, Shengwei; Dong, Youqing; Pang, Guangsheng; Zhang, Yingwei

    2015-12-16

    We report the successful construction of plasmonic core-satellite nanostructured assemblies on two-dimensional substrates, based on a strategy of combining DNA-functionalized plasmonic nanoparticles (NPs) with the specific recognition ability toward target to enable satellite NPs to self-assemble around the core immobilized on substrates. A strongly coupled plasmonic resonance band was observed because of the close proximity between core and satellite NPs, which presented significant red-shift and enhanced extinction with respect to the local surface plasmon resonance (LSPR) band of individual core NPs on the substrate. The functionality of this core-satellite nanostructured assembly as a biosensor was further explored, and the changes in extinction intensity and the peak shift of the plasmonic coupling resonance band arising from the probe-target DNA binding event all proved to be useful criteria for target DNA detection. Moreover, high selectivity down to single-base mismatched DNA was achieved using this strongly coupled plasmonic core-satellite nanostructured assembly on a substrate. Such substrate-based detection was advantageous, and its reusability and high cycle stability were demonstrated after five cycles of disassembly and reassembly. Our work demonstrates the biosensing capacity of this DNA-functionalized plasmonic nanoassembly model system on two-dimensional substrate, which is also applicable to the detection of numerous DNA-recognized biomolecules. Likewise, the presented construction method can be extended to fabricate other compositional core-satellite nanoassemblies.

  13. Self-assembled heterogeneous argon/neon core-shell clusters studied by photoelectron spectroscopy.

    Science.gov (United States)

    Lundwall, M; Pokapanich, W; Bergersen, H; Lindblad, A; Rander, T; Ohrwall, G; Tchaplyguine, M; Barth, S; Hergenhahn, U; Svensson, S; Björneholm, O

    2007-06-01

    Clusters formed by a coexpansion process of argon and neon have been studied using synchrotron radiation. Electrons from interatomic Coulombic decay as well as ultraviolet and x-ray photoelectron spectroscopy were used to determine the heterogeneous nature of the clusters and the cluster structure. Binary clusters of argon and neon produced by coexpansion are shown to exhibit a core-shell structure placing argon in the core and neon in the outer shells. Furthermore, the authors show that 2 ML of neon on the argon core is sufficient for neon valence band formation resembling the neon solid. For 1 ML of neon the authors observe a bandwidth narrowing to about half of the bulk value.

  14. Detection of hepatitis C virus core antigen for early diagnosis of hepatitis C virus infection in plasma donor in China

    Institute of Scientific and Technical Information of China (English)

    He-Qiu Zhang; Shao-Bo Li; Guo-Hua Wang; Kun Chen; Xiao-Guo Song; Xiao-Yan Feng

    2007-01-01

    AIM: To evaluate the efficacy of a new hepatitis C virus (HCV) core antigen assay developed in China.METHODS: After the determination of HCV infection, 49 serial samples were selected from 11 regular plasma donors in 5 different plasma stations. To compare the performance of HCV core antigen detection and HCV PCR, these samples were genotyped, and each specimen was analyzed by ELISA for the detection of HCV core antigen and by qualitative HCV PCR.RESULTS: Among all of the sequential samples, the original 13 specimens were HCV RNA-negative, and 36 samples were HCV RNA-positive. Twenty-seven samples (75%) were HCV core antigen-positive from these HCV RNA-positive specimens. Conversely, 27 samples (93.1%) were found HCV RNA-positive in HCV core antigen-positive samples. Intervals between HCV RNA and HCV core antigen-positive, as well as between HCV core antigen-positive and HCV antibody-positive were 36.0 and 32.8 d, respectively.CONCLUSION: This HCV core antigen assay, developed in China, is able to detect much of anti-HCV-negative, HCV RNA-positive preseroconversion window period (PWP) plasma donations.

  15. Self-assembly of core-polyethylene glycol-lipid shell (CPLS) nanoparticles and their potential as drug delivery vehicles

    Science.gov (United States)

    Shen, Zhiqiang; Loe, David T.; Awino, Joseph K.; Kröger, Martin; Rouge, Jessica L.; Li, Ying

    2016-08-01

    Herein a new multifunctional formulation, referred to as a core-polyethylene glycol-lipid shell (CPLS) nanoparticle, has been proposed and studied in silico via large scale coarse-grained molecular dynamics simulations. A PEGylated core with surface tethered polyethylene glycol (PEG) chains is used as the starting configuration, where the free ends of the PEG chains are covalently bonded with lipid molecules (lipid heads). A complete lipid bilayer is formed at the surface of the PEGylated particle core upon addition of free lipids, driven by the hydrophobic properties of the lipid tails, leading to the formation of a CPLS nanoparticle. The self-assembly process is found to be sensitive to the grafting density and molecular weight of the tethered PEG chains, as well as the amount of free lipids added. At low grafting densities the assembly of CPLS nanoparticles cannot be accomplished. As demonstrated by simulations, a lipid bud/vesicle can be formed on the surface when an excess amount of free lipids is added at high grafting density. Therefore, the CPLS nanoparticles can only be formed under appropriate conditions of both PEG and free lipids. The CPLS nanoparticle has been recognized to be able to store a large quantity of water molecules, particularly with high molecular weight of PEG chains, indicating its capacity for carrying hydrophilic molecules such as therapeutic biomolecules or imaging agents. Under identical size and surface chemistry conditions of a liposome, it has been observed that the CPLS particle can be more efficiently wrapped by the lipid membrane, indicating its potential for a greater efficiency in delivering its hydrophilic cargo. As a proof-of-concept, the experimental realization of CPLS nanoparticles is explicitly demonstrated in this study. To test the capacity of the CPLS to store small molecule cargo a hydrophilic dye was successfully encapsulated in the particles' water soluble layer. The results of this study show the power and

  16. Self-assembled core-polyethylene glycol-lipid shell nanoparticles demonstrate high stability in shear flow.

    Science.gov (United States)

    Shen, Zhiqiang; Ye, Huilin; Kröger, Martin; Li, Ying

    2017-05-24

    A core-polyethylene glycol-lipid shell (CPLS) nanoparticle consists of an inorganic core coated with polyethylene glycol (PEG) polymers, surrounded by a lipid bilayer shell. It can be self-assembled from a PEGylated core with surface-tethered PEG chains, where all the distal ends are covalently bonded to lipid molecules. Upon adding free lipids, a complete lipid bilayer shell can be formed on the surface driven by the hydrophobic nature of lipid tails, leading to the formation of a CPLS nanoparticle. The stability of CPLS nanoparticles in shear flow has been systematically studied through large scale dissipative particle dynamics simulations. CPLS nanoparticles demonstrate higher stability and less deformation in shear flow, compared with lipid vesicles. Burst leakage of drug molecules inside lipid vesicles and CPLS NPs can be induced by the large pores at their tips. These pores are initiated by the maximum stress in the waist region. It further grows along with the tank-treading motion of vesicles or CPLS NPs in shear flow. However, due to the constraints applied by PEG polymers, CPLS NPs are less deformed than vesicles with comparable size under the same flow conditions. Thus, the less deformed CPLS NPs express a smaller maximum stress at waists, demonstrating higher stability. Pore formation at waists, evolving into large pores on vesicles, leads to the burst leakage of drug molecules and complete rupture of vesicles. In contrast, although similar drug leakage in CPLS nanoparticles can occur at high shear rates, pores initiated at moderate shear rates tend to be short-lived and close due to the constraints mediated by PEG polymers. This kind of 'self-healing' capability can be observed over a wide range of shear rates for CPLS nanoparticles. Our results suggest self-assembled CPLS nanoparticles to exhibit high stability during blood circulation without rapid drug leakage. These features make CPLS nanoparticles candidates for a promising drug delivery platform.

  17. Cell-Free Hepatitis B Virus Capsid Assembly Dependent on the Core Protein C-Terminal Domain and Regulated by Phosphorylation

    Science.gov (United States)

    Ludgate, Laurie; Liu, Kuancheng; Luckenbaugh, Laurie; Streck, Nicholas; Eng, Stacey; Voitenleitner, Christian; Delaney, William E.

    2016-01-01

    ABSTRACT Multiple subunits of the hepatitis B virus (HBV) core protein (HBc) assemble into an icosahedral capsid that packages the viral pregenomic RNA (pgRNA). The N-terminal domain (NTD) of HBc is sufficient for capsid assembly, in the absence of pgRNA or any other viral or host factors, under conditions of high HBc and/or salt concentrations. The C-terminal domain (CTD) is deemed dispensable for capsid assembly although it is essential for pgRNA packaging. We report here that HBc expressed in a mammalian cell lysate, rabbit reticulocyte lysate (RRL), was able to assemble into capsids when (low-nanomolar) HBc concentrations mimicked those achieved under conditions of viral replication in vivo and were far below those used previously for capsid assembly in vitro. Furthermore, at physiologically low HBc concentrations in RRL, the NTD was insufficient for capsid assembly and the CTD was also required. The CTD likely facilitated assembly under these conditions via RNA binding and protein-protein interactions. Moreover, the CTD underwent phosphorylation and dephosphorylation events in RRL similar to those seen in vivo which regulated capsid assembly. Importantly, the NTD alone also failed to accumulate in mammalian cells, likely resulting from its failure to assemble efficiently. Coexpression of the full-length HBc rescued NTD assembly in RRL as well as NTD expression and assembly in mammalian cells, resulting in the formation of mosaic capsids containing both full-length HBc and the NTD. These results have important implications for HBV assembly during replication and provide a facile cell-free system to study capsid assembly under physiologically relevant conditions, including its modulation by host factors. IMPORTANCE Hepatitis B virus (HBV) is an important global human pathogen and the main cause of liver cancer worldwide. An essential component of HBV is the spherical capsid composed of multiple copies of a single protein, the core protein (HBc). We have

  18. Assembly of carbon-SnO2 core-sheath composite nanofibers for superior lithium storage.

    Science.gov (United States)

    Ji, Liwen; Lin, Zhan; Guo, Bingkun; Medford, Andrew J; Zhang, Xiangwu

    2010-10-11

    Protective coating: Carbon-SnO(2) core-sheath composite nanofibers are synthesized through the creative combination of electrospinning and electrodeposition processes (see figure). They display excellent electrochemical performance when directly used as binder-free anodes for rechargeable lithium ion batteries. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Special Sm core complex functions in assembly of the U2 small nuclear ribonucleoprotein of Trypanosoma brucei.

    Science.gov (United States)

    Preusser, Christian; Palfi, Zsofia; Bindereif, Albrecht

    2009-08-01

    The processing of polycistronic pre-mRNAs in trypanosomes requires the spliceosomal small ribonucleoprotein complexes (snRNPs) U1, U2, U4/U6, U5, and SL, each of which contains a core of seven Sm proteins. Recently we reported the first evidence for a core variation in spliceosomal snRNPs; specifically, in the trypanosome U2 snRNP, two of the canonical Sm proteins, SmB and SmD3, are replaced by two U2-specific Sm proteins, Sm15K and Sm16.5K. Here we identify the U2-specific, nuclear-localized U2B'' protein from Trypanosoma brucei. U2B'' interacts with a second U2 snRNP protein, U2-40K (U2A'), which in turn contacts the U2-specific Sm16.5K/15K subcomplex. Together they form a high-affinity, U2-specific binding complex. This trypanosome-specific assembly differs from the mammalian system and provides a functional role for the Sm core variation found in the trypanosomal U2 snRNP.

  20. Study of interaction of hot core plasma sources and micro-shock waves

    Science.gov (United States)

    Chelikani, Leela; Bagchi, Suman; Paturi, Prem Kiran

    2013-10-01

    Laser Induced Shockwaves (LISWs) have many applications from material processing to therapeutics. In almost all the processes and applications, understanding the conversion of laser energy to kinetic energy propagating as a shockwave (SW) is essential. We present the results on interaction of multiple plasma sources leading to SWs generated using Nd:YAG laser pulses (532 nm, 7 ns) (a) in atmospheric air and (b) from 1-D periodic structured surfaces (PSS) of 30 μm depth and 240 +/- 20 μm diameter having 25 and 64 lpi (lines per inch). Using time resolved shadowgraphy the novel aspects of (1) the presence of two distinct sources of ionization along the laser propagation direction modifying the nature of SWs around the focal plane and (2) the interaction of these two sources leading to the transition of hot core plasma in air analogous to that of a cavitation bubble in fluids are presented. Analogous phenomena of modification SW nature were observed from 1-D PSS. The effect of surface modulation on the SW and Contact Front dynamics was compared from that of a flat surface (FS). The initial studies in two different media indicate the possibility to control the SWs, either accelerate or decelerate by varying the plasma dynamics. Defence Research and Development Organization, India.

  1. Plasma diagnostics in two kinematic classes of CMEs observed by the Atmospheric Imaging Assembly onboard the Solar Dynamic Observatory

    Science.gov (United States)

    Chmielewska, E.; Tomczak, M.; Kołomański, S.; Mrozek, T.

    2016-11-01

    In order to study the dynamics and thermal properties of two kinematic classes of coronal mass ejections (CMEs) we analyzed two well-observed events in the early stage of their propagation, using multiwavelength observations from the Atmospheric Imaging Assembly (AIA) of the Solar Dynamic Observatory (SDO). For deriving differential emission measure (DEM) profiles and DEM maps of the basic structures of CMEs, we used two methods: the regularized inversion and the iterative forward-fitting approach. For the CME associated with a M2.0 class flare (CME-FL), we identified a hot, moving, blob-like feature which seems to be a candidate for a CME flux rope. Furthermore, an expanding system of loop and coronal dimming was clearly seen in AIA images. For the CME related to an eruptive prominence (CME-EP), we observed an eruptive plasmoid and a failed-eruption of cold plasma. However, we also recognized warm and hot moving signatures that revealed a multi-temperature nature of the eruptive prominence. Our main results are as follows: (a) An analysis of the examples of the two different kinematic classes of CMEs shows that despite the slight variations in the values of speeds and accelerations (CME-FL: v≈174 km s-1, a&ap350 m s-2; CME-EP: v≈135 km s-1, a≈160 m s-2) they present the same kinematic behavior; (b) in the field of view of the LASCO coronagraphs these two events have the similar, positive accelerations; (c) for both events we observed an impulsive acceleration phase (IAP); (d) the expanding structures seen in 171 Å, 193 Å, 211 Å in both events move faster than the hotter blobs; (e) the plasmoid core for the CME-FL is hot (8.0-15.8 MK); (f) the expanding blob and the hot structure in the prominence region for the CME-EP event have the similar temperature range (0.8-2.5 MK).

  2. The Numerical Tokamak Project (NTP) simulation of turbulent transport in the core plasma: A grand challenge in plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    The long-range goal of the Numerical Tokamak Project (NTP) is the reliable prediction of tokamak performance using physics-based numerical tools describing tokamak physics. The NTP is accomplishing the development of the most advanced particle and extended fluid model`s on massively parallel processing (MPP) environments as part of a multi-institutional, multi-disciplinary numerical study of tokamak core fluctuations. The NTP is a continuing focus of the Office of Fusion Energy`s theory and computation program. Near-term HPCC work concentrates on developing a predictive numerical description of the core plasma transport in tokamaks driven by low-frequency collective fluctuations. This work addresses one of the greatest intellectual challenges to our understanding of the physics of tokamak performance and needs the most advanced computational resources to progress. We are conducting detailed comparisons of kinetic and fluid numerical models of tokamak turbulence. These comparisons are stimulating the improvement of each and the development of hybrid models which embody aspects of both. The combination of emerging massively parallel processing hardware and algorithmic improvements will result in an estimated 10**2--10**6 performance increase. Development of information processing and visualization tools is accelerating our comparison of computational models to one another, to experimental data, and to analytical theory, providing a bootstrap effect in our understanding of the target physics. The measure of success is the degree to which the experimentally observed scaling of fluctuation-driven transport may be predicted numerically. The NTP is advancing the HPCC Initiative through its state-of-the-art computational work. We are pushing the capability of high performance computing through our efforts which are strongly leveraged by OFE support.

  3. MAGNETIC CORE SHELL STRUCTURES: from 0D to 1D assembling.

    Science.gov (United States)

    Ficai, Denisa; Ficai, Anton; Dinu, Elena; Oprea, Ovidiu; Sonmez, Maria; Keler, Memduh Kagan; Sahin, Yesim Muge; Ekren, Nazmi; Inan, Ahmet Talat; Daglilar, Sibel; Gunduz, Oguzhan

    2015-01-01

    Material research and development studies are focused on different techniques of bringing out nanomaterials with desired characteristics and properties. From the point of view of materials development, nowadays scientists are strongly focused on obtaining materials with predefined characteristics and properties. The morphology control seems to be a determinant factor and increasing attention is devoted to this aspect. At this moment it is possible to engineer the material's features by using different methods and materials combination for both medical and industrial applications. In the applications of chemistry and synthesis, biology, mechanics, optics solar cells and microelectronics tailoring the adjustable parameters of stoichiometry, chemical structure, shape and segregation are evaluated and opens new fields. Because of the magnetic features of nanoparticles and durable particle size, less than 100 nm, this study is aiming to describe their uses in practical applications. That's why the whole hydrodynamic magnetic core shell topic will be reviewed on this paper. Additionally, the properties acting in general sight in solid-state physics are utilized for material selection and for defining issue connecting the core, shell structure and their producing properties. Here, in the study of core/shell nanoparticle various physical and chemical synthesis routes and the effect of electrospun method are briefly discussed. Starting from a real void of the scientific literature, the existent data related to the 1D magnetic electrospun materials are reviewed. The perspectives in the medical, environmental or energetic sector is great and bring some real advantages related to the 0D core@shell structures because both mechanical and biological properties are dependent on the morphology of the materials.

  4. CORE

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Hundebøll, Martin

    2013-01-01

    different flows. Instead of maintaining these approaches separate, we propose a protocol (CORE) that brings together these coding mechanisms. Our protocol uses random linear network coding (RLNC) for intra- session coding but allows nodes in the network to setup inter- session coding regions where flows...... intersect. Routes for unicast sessions are agnostic to other sessions and setup beforehand, CORE will then discover and exploit intersecting routes. Our approach allows the inter-session regions to leverage RLNC to compensate for losses or failures in the overhearing or transmitting process. Thus, we...... increase the benefits of XORing by exploiting the underlying RLNC structure of individual flows. This goes beyond providing additional reliability to each individual session and beyond exploiting coding opportunistically. Our numerical results show that CORE outperforms both forwarding and COPE...

  5. CORE

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Hundebøll, Martin

    2013-01-01

    different flows. Instead of maintaining these approaches separate, we propose a protocol (CORE) that brings together these coding mechanisms. Our protocol uses random linear network coding (RLNC) for intra- session coding but allows nodes in the network to setup inter- session coding regions where flows...... intersect. Routes for unicast sessions are agnostic to other sessions and setup beforehand, CORE will then discover and exploit intersecting routes. Our approach allows the inter-session regions to leverage RLNC to compensate for losses or failures in the overhearing or transmitting process. Thus, we...... increase the benefits of XORing by exploiting the underlying RLNC structure of individual flows. This goes beyond providing additional reliability to each individual session and beyond exploiting coding opportunistically. Our numerical results show that CORE outperforms both forwarding and COPE...

  6. Deconstruction of archaeal genome depict strategic consensus in core pathways coding sequence assembly.

    Directory of Open Access Journals (Sweden)

    Ayon Pal

    Full Text Available A comprehensive in silico analysis of 71 species representing the different taxonomic classes and physiological genre of the domain Archaea was performed. These organisms differed in their physiological attributes, particularly oxygen tolerance and energy metabolism. We explored the diversity and similarity in the codon usage pattern in the genes and genomes of these organisms, emphasizing on their core cellular pathways. Our thrust was to figure out whether there is any underlying similarity in the design of core pathways within these organisms. Analyses of codon utilization pattern, construction of hierarchical linear models of codon usage, expression pattern and codon pair preference pointed to the fact that, in the archaea there is a trend towards biased use of synonymous codons in the core cellular pathways and the Nc-plots appeared to display the physiological variations present within the different species. Our analyses revealed that aerobic species of archaea possessed a larger degree of freedom in regulating expression levels than could be accounted for by codon usage bias alone. This feature might be a consequence of their enhanced metabolic activities as a result of their adaptation to the relatively O2-rich environment. Species of archaea, which are related from the taxonomical viewpoint, were found to have striking similarities in their ORF structuring pattern. In the anaerobic species of archaea, codon bias was found to be a major determinant of gene expression. We have also detected a significant difference in the codon pair usage pattern between the whole genome and the genes related to vital cellular pathways, and it was not only species-specific but pathway specific too. This hints towards the structuring of ORFs with better decoding accuracy during translation. Finally, a codon-pathway interaction in shaping the codon design of pathways was observed where the transcription pathway exhibited a significantly different coding

  7. Core charge distribution and self assembly of columnar phases: the case of triphenylenes and azatriphenylenes

    Directory of Open Access Journals (Sweden)

    Berardi Roberto

    2007-06-01

    Full Text Available Abstract Background The relation betweeen the structure of discotic molecules and columnar properties, a crucial point for the realization of new advanced materials, is still largely unknown. A paradigmatic case is that hexa-alkyl-thio substituted triphenylenes present mesogenic behavior while the corresponding azatriphenylenes, similar in shape and chemical structure, but with a different core charge distribution, do not form any liquid crystalline mesophase. This study is aimed at investigating, with the help of computer simulations techniques, the effects on phase behaviour of changes of the charge distribution in the discotic core. Results We described the shape and the pair, dispersive and electrostatic, interactions of hexa alkyl triphenylenes by uniaxial Gay-Berne discs with embedded point charges. Gay-Berne parameters were deduced by fitting the dispersive energies obtained from an atomistic molecular dynamics simulation of a small sample of hexa-octyl-thio triphenylene molecules in columnar phase, while a genetic algorithm was used to get a minimal set of point charges that properly reproduces the ab anitio electrostatic potential. We performed Monte Carlo simulations of three molecular models: the pure Gay-Berne disc, used as a reference, the Gay-Berne disc with hexa-thio triphenylene point charges, the Gay-Berne disc with hexa-thio azatriphenylene point charges. The phase diagram of the pure model evidences a rich polymorphism, with isotropic, columnar and crystalline phases at low pressure, and the appearance of nematic phase at higher pressure. Conclusion We found that the intermolecular electrostatic potential among the cores is fundamental in sta-bilizing/destabilizing columnar phases; in particular the triphenylene charge distribution stabilizes the columnar structure, while the azatriphenylene distribution suppresses its formation in favor of the nematic phase. We believe the present model could be successfully employed as the

  8. Magnetic Fe2O3-polystyrene/PPy core/shell particles: bioreactivity and self-assembly.

    Science.gov (United States)

    Mangeney, Claire; Fertani, Meriem; Bousalem, Smain; Zhicai, Ma; Ammar, Souad; Herbst, Fréderic; Beaunier, Patricia; Elaissari, Abdelhamid; Chehimi, Mohamed M

    2007-10-23

    This paper describes the synthesis of new magnetic, reactive polystyrene/polypyrrole core/shell latex particles. The core consists of a polystyrene microsphere containing gamma-Fe2O3 superparamagnetic nanoparticles (PSmag), and the shell is made of reactive N-carboxylic acid-functionalized polypyrrole (PPyCOOH). These PSmag-PPyCOOH latex particles, average diameter 220 nm, were prepared by copolymerization of pyrrole (Py) and the active carboxyl-functionalized pyrrole (PyCOOH) in the presence of PSmag particles. PNVP was used as a steric stabilizer. The functionalized polypyrrole-coated PSmag particles were characterized in terms of their particle size, surface morphology, chemical composition, and electrochemical and magnetic properties using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry, and SQUID magnetometry. Activation of the particle surface carboxyl groups was achieved using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS), which helps transform the carboxyl groups into activated ester groups (NSE). The activated particles, PSmag-PPyNSE, were further evaluated as bioadsorbents of biotin used as a model biomolecule. It was shown that biotin was immobilized at the surface of the PSmag-PPyNSE particles by forming interfacial amide groups. The assemblies of PSmag-PPyCOOH particles on glass plates were further investigated. When no magnetic field is applied, the particles assemble into 3D colloidal crystals. In contrast, under a magnetic field, one-particle-thick chains gathered in hedgehog-like architectures are obtained. Furthermore, PSmag-PPyCOOH coated ITO electrodes were shown to be electroactive and electrochemically stable, thus offering potentialities for creating novel high-specific-area materials for biosensing devices where the conducting polymer component would act as the transducer through its conductive properties.

  9. Hybrid metal-organic chalcogenide nanowires with electrically conductive inorganic core through diamondoid-directed assembly

    Science.gov (United States)

    Yan, Hao; Hohman, J. Nathan; Li, Fei Hua; Jia, Chunjing; Solis-Ibarra, Diego; Wu, Bin; Dahl, Jeremy E. P.; Carlson, Robert M. K.; Tkachenko, Boryslav A.; Fokin, Andrey A.; Schreiner, Peter R.; Vailionis, Arturas; Kim, Taeho Roy; Devereaux, Thomas P.; Shen, Zhi-Xun; Melosh, Nicholas A.

    2016-12-01

    Controlling inorganic structure and dimensionality through structure-directing agents is a versatile approach for new materials synthesis that has been used extensively for metal-organic frameworks and coordination polymers. However, the lack of `solid’ inorganic cores requires charge transport through single-atom chains and/or organic groups, limiting their electronic properties. Here, we report that strongly interacting diamondoid structure-directing agents guide the growth of hybrid metal-organic chalcogenide nanowires with solid inorganic cores having three-atom cross-sections, representing the smallest possible nanowires. The strong van der Waals attraction between diamondoids overcomes steric repulsion leading to a cis configuration at the active growth front, enabling face-on addition of precursors for nanowire elongation. These nanowires have band-like electronic properties, low effective carrier masses and three orders-of-magnitude conductivity modulation by hole doping. This discovery highlights a previously unexplored regime of structure-directing agents compared with traditional surfactant, block copolymer or metal-organic framework linkers.

  10. Hybrid metal-organic chalcogenide nanowires with electrically conductive inorganic core through diamondoid-directed assembly

    Science.gov (United States)

    Yan, Hao; Hohman, J. Nathan; Li, Fei Hua; Jia, Chunjing; Solis-Ibarra, Diego; Wu, Bin; Dahl, Jeremy E. P.; Carlson, Robert M. K.; Tkachenko, Boryslav A.; Fokin, Andrey A.; Schreiner, Peter R.; Vailionis, Arturas; Kim, Taeho Roy; Devereaux, Thomas P.; Shen, Zhi-Xun; Melosh, Nicholas A.

    2017-03-01

    Controlling inorganic structure and dimensionality through structure-directing agents is a versatile approach for new materials synthesis that has been used extensively for metal-organic frameworks and coordination polymers. However, the lack of `solid’ inorganic cores requires charge transport through single-atom chains and/or organic groups, limiting their electronic properties. Here, we report that strongly interacting diamondoid structure-directing agents guide the growth of hybrid metal-organic chalcogenide nanowires with solid inorganic cores having three-atom cross-sections, representing the smallest possible nanowires. The strong van der Waals attraction between diamondoids overcomes steric repulsion leading to a cis configuration at the active growth front, enabling face-on addition of precursors for nanowire elongation. These nanowires have band-like electronic properties, low effective carrier masses and three orders-of-magnitude conductivity modulation by hole doping. This discovery highlights a previously unexplored regime of structure-directing agents compared with traditional surfactant, block copolymer or metal-organic framework linkers.

  11. Facile Synthesis of Gold-nanoparticles-decorated Polymer Assemblies and Core-Shell Gold Nanoparticles Using Pluronic Block Copolymers

    Institute of Scientific and Technical Information of China (English)

    SHOU Qing-hui; GUO Chen; GAO Hong-shuai; ZHOU Hua-cong; LIU Chun-zhao; LIU Hui-zhou

    2011-01-01

    Abstract:Synthesis of gold nanoparticles (AuNPs) and Pluronic triblock copolymer composite in aqueous medium was studied.Gold-polymer nanocomposite with different structures was fabricated by tailoring the molar ratio of gold precursors to Pluronic P123 molecules or pH value of the P123 solution.When a lower volume ratio of [AuCl4-]/[P123] (0.05) was employed at pH 11.1,a nanostructure similar to plum pudding was obtained.AuNPs with an average diameter of 13.1 nm were embedded in Pluronic assemblies,and each one held about 21 single gold nanoparticles.When [AuCl4-]/[P123] was increased to 0.1,core-shell structure was obtained if the pH value was in the range of 10.6~11.6,while gold polyhedra were fabricated when pH value was 8.1.Typical core-shell AuNPs had an average diameter of 9.6 nm with a narrow size distribution,while gold polyhedras with a mean diameter of 12.8 nm was obtained.The specific morphologies of the resultant nanocomposite were presumably obtained due to the synergistic interaction among the reactants.

  12. ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

    Energy Technology Data Exchange (ETDEWEB)

    Lell, R. M.; Morman, J. A.; Schaefer, R.W.; McKnight, R.D.; Nuclear Engineering Division

    2009-02-23

    ZPR-6 Assembly 7 (ZPR-6/7) encompasses a series of experiments performed at the ZPR-6 facility at Argonne National Laboratory in 1970 and 1971 as part of the Demonstration Reactor Benchmark Program (Reference 1). Assembly 7 simulated a large sodium-cooled LMFBR with mixed oxide fuel, depleted uranium radial and axial blankets, and a core H/D near unity. ZPR-6/7 was designed to test fast reactor physics data and methods, so configurations in the Assembly 7 program were as simple as possible in terms of geometry and composition. ZPR-6/7 had a very uniform core assembled from small plates of depleted uranium, sodium, iron oxide, U{sub 3}O{sub 8} and Pu-U-Mo alloy loaded into stainless steel drawers. The steel drawers were placed in square stainless steel tubes in the two halves of a split table machine. ZPR-6/7 had a simple, symmetric core unit cell whose neutronic characteristics were dominated by plutonium and {sup 238}U. The core was surrounded by thick radial and axial regions of depleted uranium to simulate radial and axial blankets and to isolate the core from the surrounding room. The ZPR-6/7 program encompassed 139 separate core loadings which include the initial approach to critical and all subsequent core loading changes required to perform specific experiments and measurements. In this context a loading refers to a particular configuration of fueled drawers, radial blanket drawers and experimental equipment (if present) in the matrix of steel tubes. Two principal core configurations were established. The uniform core (Loadings 1-84) had a relatively uniform core composition. The high {sup 240}Pu core (Loadings 85-139) was a variant on the uniform core. The plutonium in the Pu-U-Mo fuel plates in the uniform core contains 11% {sup 240}Pu. In the high {sup 240}Pu core, all Pu-U-Mo plates in the inner core region (central 61 matrix locations per half of the split table machine) were replaced by Pu-U-Mo plates containing 27% {sup 240}Pu in the plutonium

  13. Studies of Behavior Melting Temperature Characteristics for Multi Thermocouple In-Core Instrument Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Donghyup; Chae, Myoungeun; Kim, Sungjin; Lee, Kyulim [Woojin inc, Hwasung (Korea, Republic of)

    2015-05-15

    Bottom-up type in-core instruments (ICIs) are used for the pressurized water reactors of OPR-1000, APR- 1400 in order to measure neutron flux and temperature in the reactor. It is a well-known technique and a proven design using years in the nuclear field. ICI consists of one pair of K-type thermocouple, five self-powered neutron detectors (SPNDs) and one back ground detector. K-type thermocouple's purpose is to measure the core exit temperature (CET) in the reactor. The CET is a very important factor for operating nuclear power plants and it is 327 .deg. C when generally operating the reactor in the nuclear power plant(NPP) in case of OPR- 1000. If the CET will exceed 650 .deg. C, Operators in the main control room should be considered to be an accident situation in accordance with a severe accident management guidance(SAMG). The Multi Thermocouple ICI is a new designed ICI assuming severe accident conditions. It consists of four more thermocouples than the existing design, so it has five Ktype thermocouples besides the thermocouple measuring CET is located in the same elevation as the ICI. Each thermocouple is able to be located in the desired location as required. The Multi Thermocouple ICI helps to measure the temperature distribution of the entire reactor. In addition, it will measure certain point of melted core because of the in-vessel debris of nuclear fuel when an accident occurs more seriously. In this paper, to simulate a circumstance such as a nuclear reactor severe accident was examined. In this study, the K-type thermocouples of Multi Thermocouple ICI was confirmed experimentally to be able to measure up to 1370 .deg. C before the thermocouples have been melted. And after the thermocouples were melted by debris, it was able to be monitored that the signal of EMF directed the infinite value of voltage. Therefore through the results of the test, it can be assumed that if any EMF data among the Multi Thermocouple ICI will direct the infinite value

  14. Assembly and stoichiometry of the core structure of the bacterial flagellar type III export gate complex.

    Science.gov (United States)

    Fukumura, Takuma; Makino, Fumiaki; Dietsche, Tobias; Kinoshita, Miki; Kato, Takayuki; Wagner, Samuel; Namba, Keiichi; Imada, Katsumi; Minamino, Tohru

    2017-08-01

    The bacterial flagellar type III export apparatus, which is required for flagellar assembly beyond the cell membranes, consists of a transmembrane export gate complex and a cytoplasmic ATPase complex. FlhA, FlhB, FliP, FliQ, and FliR form the gate complex inside the basal body MS ring, although FliO is required for efficient export gate formation in Salmonella enterica. However, it remains unknown how they form the gate complex. Here we report that FliP forms a homohexameric ring with a diameter of 10 nm. Alanine substitutions of conserved Phe-137, Phe-150, and Glu-178 residues in the periplasmic domain of FliP (FliPP) inhibited FliP6 ring formation, suppressing flagellar protein export. FliO formed a 5-nm ring structure with 3 clamp-like structures that bind to the FliP6 ring. The crystal structure of FliPP derived from Thermotoga maritia, and structure-based photo-crosslinking experiments revealed that Phe-150 and Ser-156 of FliPP are involved in the FliP-FliP interactions and that Phe-150, Arg-152, Ser-156, and Pro-158 are responsible for the FliP-FliO interactions. Overexpression of FliP restored motility of a ∆fliO mutant to the wild-type level, suggesting that the FliP6 ring is a functional unit in the export gate complex and that FliO is not part of the final gate structure. Copurification assays revealed that FlhA, FlhB, FliQ, and FliR are associated with the FliO/FliP complex. We propose that the assembly of the export gate complex begins with FliP6 ring formation with the help of the FliO scaffold, followed by FliQ, FliR, and FlhB and finally FlhA during MS ring formation.

  15. Realization of thermally durable close-packed 2D gold nanoparticle arrays using self-assembly and plasma etching.

    Science.gov (United States)

    Sivaraman, Sankar K; Santhanam, Venugopal

    2012-06-29

    Realization of thermally and chemically durable, ordered gold nanostructures using bottom-up self-assembly techniques are essential for applications in a wide range of areas including catalysis, energy generation, and sensing. Herein, we describe a modular process for realizing uniform arrays of gold nanoparticles, with interparticle spacings of 2 nm and above, by using RF plasma etching to remove ligands from self-assembled arrays of ligand-coated gold nanoparticles. Both nanoscale imaging and macroscale spectroscopic characterization techniques were used to determine the optimal conditions for plasma etching, namely RF power, operating pressure, duration of treatment, and type of gas. We then studied the effect of nanoparticle size, interparticle spacing, and type of substrate on the thermal durability of plasma-treated and untreated nanoparticle arrays. Plasma-treated arrays showed enhanced chemical and thermal durability, on account of the removal of ligands. To illustrate the application potential of the developed process, robust SERS (surface-enhanced Raman scattering) substrates were formed using plasma-treated arrays of silver-coated gold nanoparticles that had a silicon wafer or photopaper as the underlying support. The measured value of the average SERS enhancement factor (2 × 10(5)) was quantitatively reproducible on both silicon and paper substrates. The silicon substrates gave quantitatively reproducible results even after thermal annealing. The paper-based SERS substrate was also used to swab and detect probe molecules deposited on a solid surface.

  16. Realization of thermally durable close-packed 2D gold nanoparticle arrays using self-assembly and plasma etching

    Science.gov (United States)

    Sivaraman, Sankar K.; Santhanam, Venugopal

    2012-06-01

    Realization of thermally and chemically durable, ordered gold nanostructures using bottom-up self-assembly techniques are essential for applications in a wide range of areas including catalysis, energy generation, and sensing. Herein, we describe a modular process for realizing uniform arrays of gold nanoparticles, with interparticle spacings of 2 nm and above, by using RF plasma etching to remove ligands from self-assembled arrays of ligand-coated gold nanoparticles. Both nanoscale imaging and macroscale spectroscopic characterization techniques were used to determine the optimal conditions for plasma etching, namely RF power, operating pressure, duration of treatment, and type of gas. We then studied the effect of nanoparticle size, interparticle spacing, and type of substrate on the thermal durability of plasma-treated and untreated nanoparticle arrays. Plasma-treated arrays showed enhanced chemical and thermal durability, on account of the removal of ligands. To illustrate the application potential of the developed process, robust SERS (surface-enhanced Raman scattering) substrates were formed using plasma-treated arrays of silver-coated gold nanoparticles that had a silicon wafer or photopaper as the underlying support. The measured value of the average SERS enhancement factor (2 × 105) was quantitatively reproducible on both silicon and paper substrates. The silicon substrates gave quantitatively reproducible results even after thermal annealing. The paper-based SERS substrate was also used to swab and detect probe molecules deposited on a solid surface.

  17. Near Discharge Cathode Assembly Plasma Potential Measurements in a 30-cm NSTAR Type Ion Engine During Beam Extraction

    Science.gov (United States)

    Herman, Daniel A.; Gallimore, Alec D.

    2006-01-01

    Floating emissive probe plasma potential data are presented over a two-dimensional array of locations in the near Discharge Cathode Assembly (DCA) region of a 30-cm diameter ring-cusp ion thruster. Discharge plasma data are presented with beam extraction at throttling conditions comparable to the NASA TH Levels 8, 12, and 15. The operating conditions of the Extended Life Test (ELT) of the Deep Space One (DS1) flight spare ion engine, where anomalous discharge keeper erosion occurred, were TH 8 and TH 12 consequently they are of specific interest in investigating discharge keeper erosion phenomena. The data do not validate the presence of a potential hill plasma structure downstream of the DCA, which has been proposed as a possible erosion mechanism. The data are comparable in magnitude to data taken by other researchers in ring-cusp electron-bombardment ion thrusters. The plasma potential structures are insensitive to thruster throttling level with a minimum as low as 14 V measured at the DCA exit plane and increasing gradually in the axial direction. A sharp increase in plasma potential to the bulk discharge value of 26 to 28 volts, roughly 10 mm radially from DCA centerline, was observed. Plasma potential measurements indicate a low-potential plume structure that is roughly 20 mm in diameter emanating from the discharge cathode that may be attributed to a free-standing plasma double layer.

  18. Preparation, Properties, and Self-Assembly Behavior of PTFE-Based Core-Shell Nanospheres

    Directory of Open Access Journals (Sweden)

    Katia Sparnacci

    2012-01-01

    Full Text Available Nanosized PTFE-based core-shell particles can be prepared by emulsifier-free seed emulsion polymerization technique starting from spherical or rod-like PTFE seeds of different size. The shell can be constituted by the relatively high Tg polystyrene and polymethylmethacrylate as well as by low Tg polyacrylic copolymers. Peculiar thermal behavior of the PTFE component is observed due to the high degree of PTFE compartmentalization. A very precise control over the particle size can be exerted by properly adjusting the ratio between the monomers and the PTFE seed. In addition, the particle size distribution self-sharpens as the ratio monomer/PTFE increases. Samples with uniformity ratios suited to build 2D and 3D colloidal crystals are easily prepared. In particular, 2D colloidal crystal of spheres leads to very small 2D nanostructuration, useful for the preparation of masks with a combination of nanosphere lithography and reactive ion etching. 3D colloidal crystals were also obtained featuring excellent opal quality, which is a direct consequence of the monodispersity of colloids used for their growth.

  19. Terbium to Quantum Dot FRET Bioconjugates for Clinical Diagnostics: Influence of Human Plasma on Optical and Assembly Properties

    Directory of Open Access Journals (Sweden)

    Niko Hildebrandt

    2011-10-01

    Full Text Available Förster resonance energy transfer (FRET from luminescent terbium complexes (LTC as donors to semiconductor quantum dots (QDs as acceptors allows extraordinary large FRET efficiencies due to the long Förster distances afforded. Moreover, time-gated detection permits an efficient suppression of autofluorescent background leading to sub-picomolar detection limits even within multiplexed detection formats. These characteristics make FRET-systems with LTC and QDs excellent candidates for clinical diagnostics. So far, such proofs of principle for highly sensitive multiplexed biosensing have only been performed under optimized buffer conditions and interactions between real-life clinical media such as human serum or plasma and LTC-QD-FRET-systems have not yet been taken into account. Here we present an extensive spectroscopic analysis of absorption, excitation and emission spectra along with the luminescence decay times of both the single components as well as the assembled FRET-systems in TRIS-buffer, TRIS-buffer with 2% bovine serum albumin, and fresh human plasma. Moreover, we evaluated homogeneous LTC-QD FRET assays in QD conjugates assembled with either the well-known, specific biotin-streptavidin biological interaction or, alternatively, the metal-affinity coordination of histidine to zinc. In the case of conjugates assembled with biotin-streptavidin no significant interference with the optical and binding properties occurs whereas the histidine-zinc system appears to be affected by human plasma.

  20. Shaping of the axial power density distribution in the core to minimize the vapor volume fraction at the outlet of the VVER-1200 fuel assemblies

    Science.gov (United States)

    Savander, V. I.; Shumskiy, B. E.; Pinegin, A. A.

    2016-12-01

    The possibility of decreasing the vapor fraction at the VVER-1200 fuel assembly outlet by shaping the axial power density field is considered. The power density field was shaped by axial redistribution of the concentration of the burnable gadolinium poison in the Gd-containing fuel rods. The mathematical modeling of the VVER-1200 core was performed using the NOSTRA computer code.

  1. FORMATION OF FLOWER-LIKE AGGREGATES FROM SELF-ASSEMBLING OF MICELLES WITH PEO SHELLS AND CROSS-LINKED POLYACRYLAMIDE CORES

    Institute of Scientific and Technical Information of China (English)

    Chuan-qun Huang; Chun-yan Hong; Cai-yuan Pan

    2008-01-01

    Amphiphilic block copolymers, poly(ethylene oxide)-b-poly(N-acryloxysuccinimide) (PEO-b-PNAS) with various molecular weights have been successfully synthesized by atom transfer radical polymerization (ATRP) of NAS using functionalized PEO (PEO-Br) as ATRP macroinitiator. The self-assembling of the block copolymers in water, which is a good solvent for PEO and a non-solvent for PNAS, yielded spherical core-shell micelles with PNAS as core and PEO as shell. The cross-linked reaction of oxysuccinimide in PNAS chains with ethylenediamine occurred in the core of micelles,and the core cross-linked micelles were formed. The flower-like and dendritic aggregates were formed by self-assembling of the core cross-linked micelles on the glass slides or silicon wafers. Longer PNAS block in the block copolymers and higher evaporation temperature formed bigger spherical particles. The optical microscope was used to follow the formation and growth of the flower-like aggregates from the colloidal solution and the main driving forces for the self-assembling are solution fluid and interactions between PEO chains.

  2. Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein

    Directory of Open Access Journals (Sweden)

    Theo Luiz Ferraz de Souza

    2016-11-01

    Full Text Available Background Hepatitis C virus (HCV core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124 is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs in vitro. The specificity and propensity of C124 to the assembly and its implications on HCV pathogenesis are not well understood. Methods Spectroscopic techniques, transmission electron microscopy and calorimetry were used to better understand the propensity of C124 to fold or to multimerize into NLPs when subjected to different conditions or in the presence of unspecific nucleic acids of equivalent size to cellular microRNAs. Results The structural analysis indicated that C124 has low propensity to self-folding. On the other hand, for the first time, we show that C124, in the absence of nucleic acids, multimerizes into empty NLPs when subjected to a pH close to its isoelectric point (pH ≈ 12, indicating that assembly is mainly driven by charge neutralization. Isothermal calorimetry data showed that the assembly of NLPs promoted by nucleic acids is enthalpy driven. Additionally, data obtained from fluorescence correlation spectroscopy show that C124, in nanomolar range, was able to interact and to sequester a large number of short unspecific nucleic acids into NLPs. Discussion Together, our data showed that the charge neutralization is the major factor for the nucleocapsid-like particles assembly from C-terminal truncated HCV core protein. This finding suggests that HCV core protein may physically interact with unspecific cellular polyanions, which may correspond to microRNAs and mRNAs in a host cell infected by HCV, triggering their confinement into infectious particles.

  3. Plasma-Induced Wafer-Scale Self-Assembly of Silver Nanoparticles and Application to Biochemical Sensing

    Directory of Open Access Journals (Sweden)

    Yunbo Shi

    2015-06-01

    Full Text Available In this work, the wafer-scale silver nanoparticles fabricated by a self-assembly method was demonstrated based on a magnetron sputtering and plasma treatment process. Silver nanoparticles of different sizes and shapes were prepared, and the effects of the plasma treatment time, plasma gas composition, and power were systematically investigated to develop a method for low-cost and large-scale fabrication of silver nanoparticles. Furthermore, the surface-enhanced Raman scattering experiments: crystal violet, as the probe, was absorbed on the silver nanoparticles film of different size and density, and get the phenomena of surface-enhanced Raman scattering and surface-enhanced fluorescence. The results show that the proposed technique provides a rapid method for the fabrication of silver nanomaterial; the method is adaptable to large-scale production and is compatible with the fabrication of other materials and biosensors.

  4. On sulfur core level binding energies in thiol self-assembly and alternative adsorption sites: An experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Juanjuan [Institut des Sciences Moléculaires d’Orsay, Université-Paris Sud, 91405 Orsay (France); CNRS, UMR 8214, Institut des Sciences Moléculaires d’Orsay, Orsay ISMO, Bâtiment 351, Université Paris Sud, 91405 Orsay (France); Kara, Abdelkader, E-mail: abdelkader.kara@ucf.edu, E-mail: vladimir.esaulov@u-psud.fr [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Pasquali, Luca [Dipartimento di Ingegneria “E. Ferrari,” Università di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); IOM-CNR, s.s. 14, Km. 163.5 in AREA Science Park, 34149 Basovizza, Trieste (Italy); Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006 (South Africa); Bendounan, Azzedine; Sirotti, Fausto [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, F-91192 Gif-sur-Yvette Cedex (France); Esaulov, Vladimir A., E-mail: abdelkader.kara@ucf.edu, E-mail: vladimir.esaulov@u-psud.fr [Institut des Sciences Moléculaires d’Orsay, Université-Paris Sud, 91405 Orsay (France); CNRS, UMR 8214, Institut des Sciences Moléculaires d’Orsay, Orsay ISMO, Bâtiment 351, Université Paris Sud, 91405 Orsay (France); IOM-CNR, s.s. 14, Km. 163.5 in AREA Science Park, 34149 Basovizza, Trieste (Italy)

    2015-09-14

    Characteristic core level binding energies (CLBEs) are regularly used to infer the modes of molecular adsorption: orientation, organization, and dissociation processes. Here, we focus on a largely debated situation regarding CLBEs in the case of chalcogen atom bearing molecules. For a thiol, this concerns the case when the CLBE of a thiolate sulfur at an adsorption site can be interpreted alternatively as due to atomic adsorption of a S atom, resulting from dissociation. Results of an investigation of the characteristics of thiol self-assembled monolayers (SAMs) obtained by vacuum evaporative adsorption are presented along with core level binding energy calculations. Thiol ended SAMs of 1,4-benzenedimethanethiol (BDMT) obtained by evaporation on Au display an unconventional CLBE structure at about 161.25 eV, which is close to a known CLBE of a S atom on Au. Adsorption and CLBE calculations for sulfur atoms and BDMT molecules are reported and allow delineating trends as a function of chemisorption on hollow, bridge, and atop sites and including the presence of adatoms. These calculations suggest that the 161.25 eV peak is due to an alternative adsorption site, which could be associated to an atop configuration. Therefore, this may be an alternative interpretation, different from the one involving the adsorption of atomic sulfur resulting from the dissociation process of the S–C bond. Calculated differences in S(2p) CLBEs for free BDMT molecules, SH group sulfur on top of the SAM, and disulfide are also reported to clarify possible errors in assignments.

  5. Analysis of assemblies exchange in the core of a reactor BWR; Analisis del intercambio de ensambles en el nucleo de un reactor BWR

    Energy Technology Data Exchange (ETDEWEB)

    Kauil U, J. S. [Universidad Autonoma de Yucatan, Facultad de Ingenieria, Av. Industrias no contaminantes por Anillo Periferico Norte s/n, Apdo. Postal 150 Cordemex, Merida, Yucatan (Mexico); Fuentes M, L.; Castillo M, J. A.; Ortiz S, J. J.; Perusquia del Cueto, R., E-mail: san_dino@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-10-15

    The performance of the core of a boiling water reactor (BWR) was evaluated when two assemblies are exchanged during the fuel reload in erroneous way. All with the purpose of analyzing the value of the neutrons effective multiplication factor and the thermal limits for an exchange of assemblies. In their realization the mentioned study was based in a transition cycle of the Unit 1 of the nuclear power plant of Laguna Verde. The obtained results demonstrate that when carrying out an exchange between two fuel assemblies in erroneous way, with regard to the original reload, the changes in the neutrons effective multiplication factor do not present a serious problem, unless the exchange has been carried out among a very burnt assembly with one fresh, where this last is taken to the periphery. (Author)

  6. ZPR-6 assembly 7 high {sup 240} PU core : a cylindrical assemby with mixed (PU, U)-oxide fuel and a central high {sup 240} PU zone.

    Energy Technology Data Exchange (ETDEWEB)

    Lell, R. M.; Schaefer, R. W.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Nuclear Engineering Division; Inst. of Physics and Power Engineering

    2007-10-01

    Over a period of 30 years more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited to form the basis for criticality safety benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. The term 'benchmark' in a ZPR program connotes a particularly simple loading aimed at gaining basic reactor physics insight, as opposed to studying a reactor design. In fact, the ZPR-6/7 Benchmark Assembly (Reference 1) had a very simple core unit cell assembled from plates of depleted uranium, sodium, iron oxide, U3O8, and plutonium. The ZPR-6/7 core cell-average composition is typical of the interior region of liquid-metal fast breeder reactors (LMFBRs) of the era. It was one part of the Demonstration Reactor Benchmark Program,a which provided integral experiments characterizing the important features of

  7. Key steps in type III secretion system (T3SS) towards translocon assembly with potential sensor at plant plasma membrane.

    Science.gov (United States)

    Ji, Hongtao; Dong, Hansong

    2015-09-01

    Many plant- and animal-pathogenic Gram-negative bacteria employ the type III secretion system (T3SS) to translocate effector proteins from bacterial cells into the cytosol of eukaryotic host cells. The effector translocation occurs through an integral component of T3SS, the channel-like translocon, assembled by hydrophilic and hydrophobic proteinaceous translocators in a two-step process. In the first, hydrophilic translocators localize to the tip of a proteinaceous needle in animal pathogens, or a proteinaceous pilus in plant pathogens, and associate with hydrophobic translocators, which insert into host plasma membranes in the second step. However, the pilus needs to penetrate plant cell walls in advance. All hydrophilic translocators so far identified in plant pathogens are characteristic of harpins: T3SS accessory proteins containing a unitary hydrophilic domain or an additional enzymatic domain. Two-domain harpins carrying a pectate lyase domain potentially target plant cell walls and facilitate the penetration of the pectin-rich middle lamella by the bacterial pilus. One-domain harpins target plant plasma membranes and may play a crucial role in translocon assembly, which may also involve contrapuntal associations of hydrophobic translocators. In all cases, sensory components in the target plasma membrane are indispensable for the membrane recognition of translocators and the functionality of the translocon. The conjectural sensors point to membrane lipids and proteins, and a phosphatidic acid and an aquaporin are able to interact with selected harpin-type translocators. Interactions between translocators and their sensors at the target plasma membrane are assumed to be critical for translocon assembly.

  8. Highly conserved serine residue 40 in HIV-1 p6 regulates capsid processing and virus core assembly

    Directory of Open Access Journals (Sweden)

    Solbak Sara MØ

    2011-02-01

    Full Text Available Abstract Background The HIV-1 p6 Gag protein regulates the final abscission step of nascent virions from the cell membrane by the action of two late assembly (L- domains. Although p6 is located within one of the most polymorphic regions of the HIV-1 gag gene, the 52 amino acid peptide binds at least to two cellular budding factors (Tsg101 and ALIX, is a substrate for phosphorylation, ubiquitination, and sumoylation, and mediates the incorporation of the HIV-1 accessory protein Vpr into viral particles. As expected, known functional domains mostly overlap with several conserved residues in p6. In this study, we investigated the importance of the highly conserved serine residue at position 40, which until now has not been assigned to any known function of p6. Results Consistently with previous data, we found that mutation of Ser-40 has no effect on ALIX mediated rescue of HIV-1 L-domain mutants. However, the only feasible S40F mutation that preserves the overlapping pol open reading frame (ORF reduces virus replication in T-cell lines and in human lymphocyte tissue cultivated ex vivo. Most intriguingly, L-domain mediated virus release is not dependent on the integrity of Ser-40. However, the S40F mutation significantly reduces the specific infectivity of released virions. Further, it was observed that mutation of Ser-40 selectively interferes with the cleavage between capsid (CA and the spacer peptide SP1 in Gag, without affecting cleavage of other Gag products. This deficiency in processing of CA, in consequence, led to an irregular morphology of the virus core and the formation of an electron dense extra core structure. Moreover, the defects induced by the S40F mutation in p6 can be rescued by the A1V mutation in SP1 that generally enhances processing of the CA-SP1 cleavage site. Conclusions Overall, these data support a so far unrecognized function of p6 mediated by Ser-40 that occurs independently of the L-domain function, but selectively

  9. Membrane biofilm communities in full-scale membrane bioreactors are not randomly assembled and consist of a core microbiome

    KAUST Repository

    Matar, Gerald K.

    2017-06-21

    Finding efficient biofouling control strategies requires a better understanding of the microbial ecology of membrane biofilm communities in membrane bioreactors (MBRs). Studies that characterized the membrane biofilm communities in lab-and pilot-scale MBRs are numerous, yet similar studies in full-scale MBRs are limited. Also, most of these studies have characterized the mature biofilm communities with very few studies addressing early biofilm communities. In this study, five full-scale MBRs located in Seattle (Washington, U.S.A.) were selected to address two questions concerning membrane biofilm communities (early and mature): (i) Is the assembly of biofilm communities (early and mature) the result of random immigration of species from the source community (i.e. activated sludge)? and (ii) Is there a core membrane biofilm community in full-scale MBRs? Membrane biofilm (early and mature) and activated sludge (AS) samples were collected from the five MBRs, and 16S rRNA gene sequencing was applied to investigate the bacterial communities of AS and membrane biofilms (early and mature). Alpha and beta diversity measures revealed clear differences in the bacterial community structure between the AS and biofilm (early and mature) samples in the five full-scale MBRs. These differences were mainly due to the presence of large number of unique but rare operational taxonomic units (∼13% of total reads in each MBR) in each sample. In contrast, a high percentage (∼87% of total reads in each MBR) of sequence reads was shared between AS and biofilm samples in each MBR, and these shared sequence reads mainly belong to the dominant taxa in these samples. Despite the large fraction of shared sequence reads between AS and biofilm samples, simulated biofilm communities from random sampling of the respective AS community revealed that biofilm communities differed significantly from the random assemblages (P < 0.001 for each MBR), indicating that the biofilm communities (early

  10. Reduced-temperature ordering of FePt nanoparticle assembled films by Fe30Pt70/Fe3O4 core/shell structure

    Institute of Scientific and Technical Information of China (English)

    He Shu-Li; Peng Yin; Liu Li-Li; Jiang Hong-Wei; Liu Li-Feng; Zheng Wu; Wang Ai-Ling

    2007-01-01

    In this paper, Fe3oPt70/Fe3O4 core/shell nanoparticles were synthesized by chemical routine and the layered polycthylenimine (PEI)-Fe30Pt70/Fe3O4 structure was constructed by molecule-mediated self-assembly technique. The dimension of core/shell structured nanoparticles was that of 4nm core and 2 nm shell. After annealing under a flow of forming gas (50%Ar2%%30%H2) for 1h at or above 400℃, the iron oxide shell was reduced to Fe and diffused to Pt-rich core, which leaded to the formation of L10 phase FePt at low temperature. The x-ray diffraction results and magnetic properties measurement showed that the chemical ordering temperature of Fe30Pt70/Fe3O4 core/shell nanoparticles assembly can be reduced to as low as 400℃. The sample annealed at 400℃ showed the coercivity of 4 KOe with the applied field of 1.5T. The core/shell structure was suggested to be an effective way to reduce the ordering temperature obviously.

  11. Lasing in self-assembled microcavities of CdSe/CdS core/shell colloidal quantum rods

    Science.gov (United States)

    Zavelani-Rossi, Margherita; Lupo, Maria Grazia; Krahne, Roman; Manna, Liberato; Lanzani, Guglielmo

    2010-06-01

    Colloidal semiconductor quantum rods have demonstrated many advantageous properties as light emitters such as high quantum yield, tunable emission wavelength, and polarized emission. This makes them an interesting optical gain material for laser applications. We report room-temperature gain lifetimes in core/shell CdSe/CdS quantum rods exceeding 300 ps, and show that the long gain lifetimes result from the significant reduction of Auger recombination in our quantum rods, even though the electrons are delocalized over the rod volume. We also fabricate devices by deposition of small droplets of quantum rod solution onto flat substrates. The evaporation dynamics of the droplets are governed by the coffee stain effect which leads to the formation of well defined micron-size stripes. These stripes consist of densely packed, laterally aligned quantum rods and provide optical feedback originating from the abrupt changes of refractive index at the stripe borders. We exploit the optical gain and the coffee stain mediated self-assembly and show that we can fabricate novel microlasers solely by deposition of droplets of quantum rod solutions on flat substrates.

  12. Self-Assembled Core-Satellite Gold Nanoparticle Networks for Ultrasensitive Detection of Chiral Molecules by Recognition Tunneling Current.

    Science.gov (United States)

    Zhang, Yuanchao; Liu, Jingquan; Li, Da; Dai, Xing; Yan, Fuhua; Conlan, Xavier A; Zhou, Ruhong; Barrow, Colin J; He, Jin; Wang, Xin; Yang, Wenrong

    2016-05-24

    Chirality sensing is a very challenging task. Here, we report a method for ultrasensitive detection of chiral molecule l/d-carnitine based on changes in the recognition tunneling current across self-assembled core-satellite gold nanoparticle (GNP) networks. The recognition tunneling technique has been demonstrated to work at the single molecule level where the binding between the reader molecules and the analytes in a nanojunction. This process was observed to generate a unique and sensitive change in tunneling current, which can be used to identify the analytes of interest. The molecular recognition mechanism between amino acid l-cysteine and l/d-carnitine has been studied with the aid of SERS. The different binding strength between homo- or heterochiral pairs can be effectively probed by the copper ion replacement fracture. The device resistance was measured before and after the sequential exposures to l/d-carnitine and copper ions. The normalized resistance change was found to be extremely sensitive to the chirality of carnitine molecule. The results suggested that a GNP networks device optimized for recognition tunneling was successfully built and that such a device can be used for ultrasensitive detection of chiral molecules.

  13. Fabrication of Hierarchical Layer-by-Layer Assembled Diamond-based Core-Shell Nanocomposites as Highly Efficient Dye Absorbents for Wastewater Treatment

    Science.gov (United States)

    Zhao, Xinna; Ma, Kai; Jiao, Tifeng; Xing, Ruirui; Ma, Xilong; Hu, Jie; Huang, Hao; Zhang, Lexin; Yan, Xuehai

    2017-03-01

    The effective chemical modification and self-assembly of diamond-based hierarchical composite materials are of key importance for a broad range of diamond applications. Herein, we report the preparation of novel core-shell diamond-based nanocomposites for dye adsorption toward wastewater treatment through a layer-by-layer (LbL) assembled strategy. The synthesis of the reported composites began with the carboxyl functionalization of microdiamond by the chemical modification of diamond@graphene oxide composite through the oxidation of diamond@graphite. The carboxyl-terminated microdiamond was then alternatively immersed in the aqueous solution of amine-containing polyethylenimine and carboxyl-containing poly acrylic acid, which led to the formation of adsorption layer on diamond surface. Alternating (self-limiting) immersions in the solutions of the amine-containing and carboxyl-containing polymers were continued until the desired number of shell layers were formed around the microdiamond. The obtained core-shell nanocomposites were successfully synthesized and characterized by morphological and spectral techniques, demonstrating higher surface areas and mesoporous structures for good dye adsorption capacities than nonporous solid diamond particles. The LbL-assembled core-shell nanocomposites thus obtained demonstrated great adsorption capacity by using two model dyes as pollutants for wastewater treatment. Therefore, the present work on LbL-assembled diamond-based composites provides new alternatives for developing diamond hybrids as well as nanomaterials towards wastewater treatment applications.

  14. HIV-1 Viral RNA Dynamics at the Plasma Membrane May Provide Insight into Viral Assembly | Poster

    Science.gov (United States)

    Many aspects of how infectious viruses assemble in cells have yet to be completely deciphered. However, as reported in a recent Journal of Virology paper, researchers may be one step closer to understanding how HIV-1, the virus that causes AIDS, assembles and replicates.

  15. Plasma treated polyethylene terephthalate/polypropylene films assembled with chitosan and various preservatives for antimicrobial food packaging.

    Science.gov (United States)

    Lei, Jieqiong; Yang, Lingxiao; Zhan, Yingfei; Wang, Yuntao; Ye, Ting; Li, Yan; Deng, Hongbing; Li, Bin

    2014-02-01

    In this study, polyethylene terephthalate/polypropylene (PET/PP) films were treated via atmospheric pressure plasma, assembled with chitosan and various preservatives and applied for antimicrobial food packaging. Surface properties of these obtained films were studied by contact angle measurement, atomic force microscopy (ATM), X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared spectroscopy (FT-IR) and dynamic laser scattering (DLS). The above results showed that the surface hydrophilicity and roughness of the films increased after the plasma treatment. Besides, chitosan and the preservatives were successfully assembled onto the surface of the films. In addition, the antimicrobial activities of the films against three kinds of microorganisms (Staphylococcus aureus, Bacillus subtilis and Escherichia coli) were investigated and the results indicated that the inhibition ratios against B. subtilis and E. coli reached almost 100% while the inhibition ratios against S. aureus were lower than 85%. Moreover, the accumulative release profiles of the antimicrobial substances migrating from the assembled films into the release solutions revealed that their release speed increased with the increment of temperature and acidity, but decreased with enhancing the ionic strength regulated by sodium chloride or with lowering the ionic mobility regulated by sucrose.

  16. Protein-Assisted Assembly of Modular 3D Plasmonic Raspberry-like Core/Satellite Nanoclusters: Correlation of Structure and Optical Properties.

    Science.gov (United States)

    Höller, Roland P M; Dulle, Martin; Thomä, Sabrina; Mayer, Martin; Steiner, Anja Maria; Förster, Stephan; Fery, Andreas; Kuttner, Christian; Chanana, Munish

    2016-06-28

    We present a bottom-up assembly route for a large-scale organization of plasmonic nanoparticles (NPs) into three-dimensional (3D) modular assemblies with core/satellite structure. The protein-assisted assembly of small spherical gold or silver NPs with a hydrophilic protein shell (as satellites) onto larger metal NPs (as cores) offers high modularity in sizes and composition at high satellite coverage (close to the jamming limit). The resulting dispersions of metal/metal nanoclusters exhibit high colloidal stability and therefore allow for high concentrations and a precise characterization of the nanocluster architecture in dispersion by small-angle X-ray scattering (SAXS). Strong near-field coupling between the building blocks results in distinct regimes of dominant satellite-to-satellite and core-to-satellite coupling. High robustness against satellite disorder was proved by UV/vis diffuse reflectance (integrating sphere) measurements. Generalized multiparticle Mie theory (GMMT) simulations were employed to describe the electromagnetic coupling within the nanoclusters. The close correlation of structure and optical property allows for the rational design of core/satellite nanoclusters with tailored plasmonics and well-defined near-field enhancement, with perspectives for applications such as surface-enhanced spectroscopies.

  17. Self-Assembled Core-Shell-Type Lipid-Polymer Hybrid Nanoparticles: Intracellular Trafficking and Relevance for Oral Absorption.

    Science.gov (United States)

    Li, Qiuxia; Xia, Dengning; Tao, Jinsong; Shen, Aijun; He, Yuan; Gan, Yong; Wang, Chi

    2017-10-01

    Lipid-polymer hybrid nanoparticles (NPs) are advantageous for drug delivery. However, their intracellular trafficking mechanism and relevance for oral drug absorption are poorly understood. In this study, self-assembled core-shell lipid-polymer hybrid NPs made of poly(lactic-co-glycolic acid) (PLGA) and various lipids were developed to study their differing intracellular trafficking in intestinal epithelial cells and their relevance for oral absorption of a model drug saquinavir (SQV). Our results demonstrated that the endocytosis and exocytosis of hybrid NPs could be changed by varying the kind of lipid. A glyceride mixture (hybrid NPs-1) decreased endocytosis but increased exocytosis in Caco-2 cells, whereas the phospholipid (E200) (hybrid NPs-2) decreased endocytosis but exocytosis was unaffected as compared with PLGA nanoparticles. The transport of hybrid NPs-1 in cells involved various pathways, including caveolae/lipid raft-dependent endocytosis, and clathrin-mediated endocytosis and macropinocytosis, which was different from the other groups of NPs that involved only caveolae/lipid raft-dependent endocytosis. Compared with that of the reference formulation (nanoemulsion), the oral absorption of SQV-loaded hybrid NPs in rats was poor, probably due to the limited drug release and transcytosis of NPs across the intestinal epithelium. In conclusion, the intracellular processing of hybrid NPs in intestinal epithelia can be altered by adding lipids to the NP. However, it appears unfavorable to use PLGA-based NPs to improve oral absorption of SQV compared with nanoemulsion. Our findings will be essential in the development of polymer-based NPs for the oral delivery of drugs with the purpose of improving their oral absorption. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  18. A self-assembled complex with a titanium(IV) catecholate core as a potential bimodal contrast agent.

    Science.gov (United States)

    Dehaen, Geert; Eliseeva, Svetlana V; Kimpe, Kristof; Laurent, Sophie; Vander Elst, Luce; Muller, Robert N; Dehaen, Wim; Binnemans, Koen; Parac-Vogt, Tatjana N

    2012-01-01

    A ditopic chelating ligand (H(6)4) that bears catechol and diethylenetriamine-N,N,N',N'',N''-pentaacetate (DTPA) has been designed and shown to specifically bind lanthanide(III) ions at the DTPA core ([Ln(H(2)4)(H(2)O)](-)) and further self-assemble with titanium(IV), thereby giving rise to the formation of a supramolecular metallostar complex with a lanthanide(III)-to-titanium(IV) ratio of 3:1, [(Ln4)(3)Ti(H(2)O)(3)](5-) (Ln=La, Eu, Gd). The efficacy of the metallostar complex as a potential bimodal optical/magnetic resonance imaging (MRI) agent has been evaluated. Nuclear magnetic relaxation dispersion (NMRD) measurements for the [(Gd4)(3)Ti(H(2)O)(3)](5-) complex have demonstrated an enhanced r(1) relaxivity that corresponds to 36.9 s(-1) mM(-1) per metallostar molecule at 20 MHz and 310 K, which is a result of a decreased tumbling rate. The ability of the complex to bind to human serum albumin (HSA) was also examined by relaxometric measurements. In addition, upon UV irradiation the [(Gd4)(3)Ti(H(2)O)(3)](5-) complex exhibits broad-band green emission in the range 400-750 nm with a maximum at 490 nm. Taking into account the high relaxivity and luminescence properties, the [(Gd4)(3)Ti(H(2)O)(3)](5-) complex is a good lead compound for the development of efficient bimodal contrast agents.

  19. Magnetic field directed assembly of superstructures of ferrite-ferroelectric core-shell nanoparticles and studies on magneto-electric interactions

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, G., E-mail: srinivas@oakland.edu; Sreenivasulu, G.; Benoit, Crystal [Physics Department, Oakland University, Rochester, Michigan 48309 (United States); Petrov, V. M. [Physics Department, Oakland University, Rochester, Michigan 48309 (United States); Institute of Electronic and Information Systems, Novgorod State University, Veliky Novgorod 173003 (Russian Federation); Chavez, F. [Chemistry Department, Oakland University, Rochester, Michigan 48309 (United States)

    2015-05-07

    Composites of ferromagnetic and ferroelectric are of interest for studies on mechanical strain mediated magneto-electric (ME) interactions and for useful technologies. Here, we report on magnetic-field-assisted-assembly of barium titanate (BTO)-nickel ferrite (NFO) core-shell particles into linear chains and 2D/3D arrays and measurements of ME effects in such assemblies. First, we synthesized the core-shell nano-particles with 50–600 nm BTO and 10–200 nm NFO by chemical self-assembly by coating the ferroic particles with complementary coupling groups and allowing them to self-assemble in the presence of a catalyst via the “click” reaction. The core-shell structure was confirmed with electron microscopy and scanning probe microscopy. We obtained superstructure of the core-shell particles by subjecting them to a magnetic field gradient that exerts an attractive force on the particles and align them toward the regions of high field strengths. At low particle concentration, linear chains were formed and they evolved into 2D and 3D arrays at high particle concentrations. Magnetoelectric characterization on unassembled films and assembled arrays has been performed through measurements of low-frequency ME voltage coefficient (MEVC) by subjecting the sample to a bias magnetic field and an ac magnetic field. The MEVC is higher for field-assembled samples than for unassembled films and is found to be sensitive to field orientation with a higher MEVC for magnetic fields parallel to the array direction than for magnetic fields perpendicular to the array. A maximum MEVC of 20 mV/cm Oe, one of the highest reported for any bulk nanocomposite, is measured across the array thickness. A model is provided for ME coupling in the superstructures of BTO-NFO particulate composites. First, we estimated the MEVC for a free-standing BTO-NFO core-shell particle and then extended the model to include an array of linear chains of the particles. The theoretical estimates are in

  20. Step-by-step assembly preparation of core-shell Si-mesoporous TiO2 composite nanospheres with enhanced lithium-storage properties.

    Science.gov (United States)

    Sun, Lin; Wang, Fei; Su, Tingting; Du, Hong-Bin

    2017-09-12

    Core-shell structured Si-mesoporous TiO2 (Si@mTiO2) composite nanospheres are designed and prepared via a step-by-step assembly method. Si@mTiO2 exhibit excellent lithium-storage properties when used as anode materials in lithium ion batteries. The reversible specific capacity is maintained at as high as 700 mA h g(-1) with no capacity decay even after 200 cycles at 1 A g(-1).

  1. Supported Ag-TiO{sub 2} core-shell nanofibres formed at low temperature by plasma deposition

    Energy Technology Data Exchange (ETDEWEB)

    Borras, Ana; Barranco, Angel; Yubero, Francisco; Gonzalez-Elipe, Agustin R [Instituto de Ciencia de Materiales de Sevilla (CSIC-Univ. Sevilla), Avenida Americo Vespucio s/n, 41092 Sevilla (Spain)

    2006-07-28

    Ag-TiO{sub 2} nanofibres (about three {mu}m long and 30-150 nm thick) formed by a single-crystalline silver wire (20-30 nm thick) and an external layer of amorphous TiO{sub 2} of variable thickness are prepared at 403 K by oxygen plasma activation of a silver substrate followed by plasma deposition of TiO{sub 2}. Thicker fibres of anatase crystallites surrounding the silver wire were prepared when plasma deposition was carried out at 523 K. The fibres have been analysed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray photoemission spectroscopy (XPS). The plasmon losses of the silver core wire have been characterized by electron energy loss spectroscopy in the TEM microscope. Based on the experimental evidence, a new volcano-type mechanism of formation of these core-shell fibres is proposed, whereby the effect of the plasma and the high mobility of the silver would be key factors determining their morphology and dimensions.

  2. Influence of the magnetic field expansion on the core plasma in an axisymmetric mirror trap

    Science.gov (United States)

    Soldatkina, E.; Anikeev, M.; Bagryansky, P.; Korzhavina, M.; Maximov, V.; Savkin, V.; Yakovlev, D.; Yushmanov, P.; Dunaevsky, A.

    2017-02-01

    First measurements of plasma parameters in an expander of a mirror trap with sub-fusion plasma parameters are reported. Potential drop near the end plates of the expander appears to be much lower than the electron temperature in the center of the trap. Characteristic energy of electrons in the expander region is also substantially lower than the electron temperature in the confinement plasma. Variation of the magnetic field expansion ratio K between 30 and 160 does not influence the main parameters of the confinement plasma. Electron temperatures of the confinement plasma of about 700 eV were achieved at K = 30.

  3. Preparation of Biocatalytic Microparticles by Interfacial Self-Assembly of Enzyme-Nanoparticle Conjugates Around a Cross-Linkable Core.

    Science.gov (United States)

    Andler, S M; Wang, L-S; Goddard, J M; Rotello, V M

    2016-01-01

    Rational design of hierarchical interfacial assembly of reusable biocatalytic microparticles is described in this chapter. Specifically, purified enzymes and functionalized nanoparticles are electrostatically assembled at the interface of cross-linked microparticles which are formed through ring opening metathesis polymerization. The diameters of microparticle assemblies average 10μm, and they show enhanced kinetic efficiency as well as improved stability against heat, pH, and solvent denaturation when compared to stabilities of the corresponding native enzymes.

  4. Laser ablation inductively coupled plasma mass spectrometry: a new tool for trace element analysis in ice cores.

    Science.gov (United States)

    Reinhardt, H; Kriews, M; Miller, H; Schrems, O; Lüdke, C; Hoffmann, E; Skole, J

    2001-07-01

    A new method for the detection of trace elements in polar ice cores using laser ablation with subsequent inductively coupled plasma mass spectrometry analysis is described. To enable direct analysis of frozen ice samples a special laser ablation chamber was constructed. Direct analysis reduces the risk of contamination. The defined removal of material from the ice surface by means of a laser beam leads to higher spatial resolution (300-1000 microm) in comparison to investigations with molten ice samples. This is helpful for the detection of element signatures in annual layers of ice cores. The method was applied to the successful determination of traces for the elements Mg, Al, Fe, Zn, Cd, Pb, some rare-earth elements (REE) and minor constituents such as Ca and Na in ice cores. These selected elements serve as tracer elements for certain sources and their element signatures detected in polar ice cores can give hints to climate changes in the past. We report results from measurements of frozen ice samples, the achievable signal intensities, standard deviations and calibration graphs as well as the first signal progression of 205Pb in an 8,000-year-old ice core sample from Greenland. In addition, the first picture of a crater on an ice surface burnt by an IR laser made by cryogenic scanning electron microscopy is presented.

  5. Static Clathrin Assemblies at the Peripheral Vacuole-Plasma Membrane Interface of the Parasitic Protozoan Giardia lamblia.

    Science.gov (United States)

    Zumthor, Jon Paulin; Cernikova, Lenka; Rout, Samuel; Kaech, Andres; Faso, Carmen; Hehl, Adrian B

    2016-07-01

    Giardia lamblia is a parasitic protozoan that infects a wide range of vertebrate hosts including humans. Trophozoites are non-invasive but associate tightly with the enterocyte surface of the small intestine. This narrow ecological specialization entailed extensive morphological and functional adaptations during host-parasite co-evolution, including a distinctly polarized array of endocytic organelles termed peripheral vacuoles (PVs), which are confined to the dorsal cortical region exposed to the gut lumen and are in close proximity to the plasma membrane (PM). Here, we investigated the molecular consequences of these adaptations on the Giardia endocytic machinery and membrane coat complexes. Despite the absence of canonical clathrin coated vesicles in electron microscopy, Giardia possesses conserved PV-associated clathrin heavy chain (GlCHC), dynamin-related protein (GlDRP), and assembly polypeptide complex 2 (AP2) subunits, suggesting a novel function for GlCHC and its adaptors. We found that, in contrast to GFP-tagged AP2 subunits and DRP, CHC::GFP reporters have no detectable turnover in living cells, indicating fundamental differences in recruitment to the membrane and disassembly compared to previously characterized clathrin coats. Histochemical localization in electron tomography showed that these long-lived GlCHC assemblies localized at distinctive approximations between the plasma and PV membrane. A detailed protein interactome of GlCHC revealed all of the conserved factors in addition to novel or highly diverged proteins, including a putative clathrin light chain and lipid-binding proteins. Taken together, our data provide strong evidence for giardial CHC as a component of highly stable assemblies at PV-PM junctions that likely have a central role in organizing continuities between the PM and PV membranes for controlled sampling of the fluid environment. This suggests a novel function for CHC in Giardia and the extent of molecular remodeling of

  6. Role of the HIV-1 Matrix Protein in Gag Intracellular Trafficking and Targeting to the Plasma Membrane for Virus Assembly

    Directory of Open Access Journals (Sweden)

    Ruba H Ghanam

    2012-02-01

    Full Text Available Human immunodeficiency virus type-1 (HIV-1 encodes a polypeptide called Gag that is able to form virus-like particles (VLPs in vitro in the absence of any cellular or viral constituents. During the late phase of the HIV-1 infection, Gag polyproteins are transported to the plasma membrane (PM for assembly. In the past two decades, in vivo, in vitro and structural studies have shown that Gag trafficking and targeting to the PM are orchestrated events that are dependent on multiple factors including cellular proteins and specific membrane lipids. The matrix (MA domain of Gag has been the focus of these studies as it appears to be engaged in multiple intracellular interactions that are suggested to be critical for virus assembly and replication. The interaction between Gag and the PM is perhaps the most understood. It is now established that the ultimate localization of Gag on punctate sites on the PM is mediated by specific interactions between the MA domain of Gag and phosphatidylinositol-4,5-bisphosphate (PI(4,5P2, a minor lipid localized on the inner leaflet of the PM. Structure-based studies revealed that binding of PI(4,5P2 to MA induces minor conformational changes, leading to exposure of the myristyl (myr group. Exposure of the myr group is also triggered by binding of calmodulin, enhanced by factors that promote protein self-association like the capsid domain of Gag, and is modulated by pH. Despite the steady progress in defining both the viral and cellular determinants of retroviral assembly and release, Gag’s intracellular interactions and trafficking to its assembly sites in the infected cell are poorly understood. In this review, we summarize the current understanding of the structural and functional role of MA in HIV replication.

  7. Structure of the cytoplasmic domain of TcpE, the inner membrane core protein required for assembly of the Vibrio cholerae toxin-coregulated pilus.

    Science.gov (United States)

    Kolappan, Subramaniapillai; Craig, Lisa

    2013-04-01

    Type IV pili are long thin surface-displayed polymers of the pilin subunit that are present in a diverse group of bacteria. These multifunctional filaments are critical to virulence for pathogens such as Vibrio cholerae, which use them to form microcolonies and to secrete the colonization factor TcpF. The type IV pili are assembled from pilin subunits by a complex inner membrane machinery. The core component of the type IV pilus-assembly platform is an integral inner membrane protein belonging to the GspF superfamily of secretion proteins. These proteins somehow convert chemical energy from ATP hydrolysis by an assembly ATPase on the cytoplasmic side of the inner membrane to mechanical energy for extrusion of the growing pilus filament out of the inner membrane. Most GspF-family inner membrane core proteins are predicted to have N-terminal and central cytoplasmic domains, cyto1 and cyto2, and three transmembrane segments, TM1, TM2 and TM3. Cyto2 and TM3 represent an internal repeat of cyto1 and TM1. Here, the 1.88 Å resolution crystal structure of the cyto1 domain of V. cholerae TcpE, which is required for assembly of the toxin-coregulated pilus, is reported. This domain folds as a monomeric six-helix bundle with a positively charged membrane-interaction face at one end and a hydrophobic groove at the other end that may serve as a binding site for partner proteins in the pilus-assembly complex.

  8. Oriented carbon nanostructures grown by hot-filament plasma-enhanced CVD from self-assembled Co-based catalyst on Si substrates

    Science.gov (United States)

    Fleaca, Claudiu Teodor; Morjan, Ion; Rodica, Alexandrescu; Dumitrache, Florian; Soare, Iuliana; Gavrila-Florescu, Lavinia; Sandu, Ion; Dutu, Elena; Le Normand, François; Faerber, Jacques

    2012-03-01

    We report the synthesis of coral- and caterpillar-like carbon nanostructures assemblies starting from cobalt nitrate ethanol solutions deposited by drop-casting onto blank or carbon nanoparticles film covered Si(1 0 0) substrates. The seeded films were pre-treated with glow discharge hydrogen plasma aided by hot-filaments at 550 °C followed by introduction of acetylene at 700 °C. The resultant carbon nanostructure assemblies contain a high density of aligned carbon nanotubes/nanofibers (CNTs/CNFs). The influence of the forces that act during liquid-mediated self-assembly of Co catalyst precursor is discussed.

  9. Preparation of Core-Shell Coordination Molecular Assemblies via the Enrichment of Structure-Directing "Codes" of Bridging Ligands and Metathesis of Metal Units

    Energy Technology Data Exchange (ETDEWEB)

    Park, J; Chen, YP; Perry, Z; Li, JR; Zhou, HC

    2014-12-03

    A series of molybdenum- and copper-based MOPs were synthesized through coordination-driven process of a bridging ligand (3,3'-PDBAD, L-1) and dimetal paddlewheel clusters. Three conformers of the ligand exist with an ideal bridging angle between the two carboxylate groups of 0 degrees (H-2 zeta-L(1)), 120 degrees (H-2 beta-L-1), and of 90 degrees (H-2 beta-L-1), respectively. At ambient or lower temperature, (HL1)-L-2 and Mo-2(OAc)(4) or Cu-2(OAc)(4) were crystallized into a molecular square with ?-L-1 and Mo-2/Cu-2 units. With proper temperature elevation, not only the molecular square with ?-L-1 but also a lantern-shaped cage with a-L-1 formed simultaneously. Similar to how Watson-Crick pairs stabilize the helical structure of duplex DNA, the core-shell molecular assembly possesses favorable H-bonding interaction sites. This is dictated by the ligand conformation in the shell, coding for the formation and providing stabilization of the central lantern shaped core, which was not observed without this complementary interaction. On the basis of the crystallographic implications, a heterobimetallic cage was obtained through a postsynthetic metal ion metathesis, showing different reactivity of coordination bonds in the core and shell. As an innovative synthetic strategy, the site-selective metathesis broadens the structural diversity and properties of coordination assemblies.

  10. Lithium Coatings on NSTX Plasma Facing Components and Its Effects On Boundary Control, Core Plasma Performance, and Operation

    Energy Technology Data Exchange (ETDEWEB)

    H.W.Kugel, M.G.Bell, H.Schneider, J.P.Allain, R.E.Bell, R Kaita, J.Kallman, S. Kaye, B.P. LeBlanc, D. Mansfield, R.E. Nygen, R. Maingi, J. Menard, D. Mueller, M. Ono, S. Paul, S.Gerhardt, R.Raman, S.Sabbagh, C.H.Skinner, V.Soukhanovskii, J.Timberlake, L.E.Zakharov, and the NSTX Research Team

    2010-01-25

    NSTX high-power divertor plasma experiments have used in succession lithium pellet injection (LPI), evaporated lithium, and injected lithium powder to apply lithium coatings to graphite plasma facing components. In 2005, following wall conditioning and LPI, discharges exhibited edge density reduction and performance improvements. Since 2006, first one, and now two lithium evaporators have been used routinely to evaporate lithium onto the lower divertor region at total rates of 10-70 mg/min for periods 5-10 min between discharges. Prior to each discharge, the evaporators are withdrawn behind shutters. Significant improvements in the performance of NBI heated divertor discharges resulting from these lithium depositions were observed. These evaporators are now used for more than 80% of NSTX discharges. Initial work with injecting fine lithium powder into the edge of NBI heated deuterium discharges yielded comparable changes in performance. Several operational issues encountered with lithium wall conditions, and the special procedures needed for vessel entry are discussed. The next step in this work is installation of a Liquid Lithium Divertor surface on the outer part of the lower divertor.

  11. Colloidal Gold--Collagen Protein Core--Shell Nanoconjugate: One-Step Biomimetic Synthesis, Layer-by-Layer Assembled Film, and Controlled Cell Growth.

    Science.gov (United States)

    Xing, Ruirui; Jiao, Tifeng; Yan, Linyin; Ma, Guanghui; Liu, Lei; Dai, Luru; Li, Junbai; Möhwald, Helmuth; Yan, Xuehai

    2015-11-11

    The biogenic synthesis of biomolecule-gold nanoconjugates is of key importance for a broad range of biomedical applications. In this work, a one-step, green, and condition-gentle strategy is presented to synthesize stable colloidal gold-collagen core-shell nanoconjugates in an aqueous solution at room temperature, without use of any reducing agents and stabilizing agents. It is discovered that electrostatic binding between gold ions and collagen proteins and concomitant in situ reduction by hydroxyproline residues are critically responsible for the formation of the core-shell nanoconjugates. The film formed by layer-by-layer assembly of such colloidal gold-collagen nanoconjugates can notably improve the mechanical properties and promote cell adhesion, growth, and differentiation. Thus, the colloidal gold-collagen nanoconjugates synthesized by such a straightforward and clean manner, analogous to a biomineralization pathway, provide new alternatives for developing biologically based hybrid biomaterials toward a range of therapeutic and diagnostic applications.

  12. 2-D Magnetohydrodynamic Simulations of Induced Plasma Dynamics in the Near-Core Region of a Galaxy Cluster

    CERN Document Server

    Mikellides, Ioannis G; Yorke, Harold W

    2010-01-01

    We present results from numerical simulations of the cooling-core cluster A2199 produced by the two-dimensional (2-D) resistive magnetohydrodynamics (MHD) code MACH2. In our simulations we explore the effect of anisotropic thermal conduction on the energy balance of the system. The results from idealized cases in 2-D axisymmetric geometry underscore the importance of the initial plasma density in ICM simulations, especially the near-core values since the radiation cooling rate is proportional to ${n_e}^2$. Heat conduction is found to be non-effective in preventing catastrophic cooling in this cluster. In addition we performed 2-D planar MHD simulations starting from initial conditions deliberately violating both thermal balance and hydrostatic equilibrium in the ICM, to assess contributions of the convective terms in the energy balance of the system against anisotropic thermal conduction. We find that in this case work done by the pressure on the plasma can dominate the early evolution of the internal energy ...

  13. Analysis of Al and Fe transport coefficients in LHD core plasmas based on space-resolved EUV spectroscopy

    Science.gov (United States)

    Huang, Xianli; Morita, Shigeru; Oishi, Tetsutarou; Murakami, Izumi; Goto, Motoshi; Zhang, Hongming; Liu, Yang

    2016-10-01

    With impurity pellet injection and a one-dimensional transport code, the transport of Al and Fe ions has been analyzed in the Large Helical Device (LHD) based on extreme ultraviolet (EUV) space-resolved spectroscopy. The total density of Fe ions in the plasma core has been analyzed from the radial profiles of the Fe n =3-2 Lα emissions. When the ne profile is peaked or hollow, the Fe density also exhibits a peaked or hollow profile, respectively. Fe transport analysis shows that the convective velocity (V) is outward in the plasma core and inward near the edge when the ne profile is hollow. On the other hand, the V takes negative value over the whole radial range in the peaked ne profile. Therefore, the different Fe density profiles between peaked and hollow ne profiles can be explained by the significant difference in the V profile. Comparison of the transport coefficients between Al and Fe shows the magnitude of V for Al ions seems to be smaller than that for Fe ions while the difference in the diffusion coefficient profile is not significant. The difference in the decay time of line emissions between the two speices is attributed to the weaker convection for the Al.

  14. "Hot" Non-flaring Plasmas in Active Region Cores Heated by Single Nanoflares

    Science.gov (United States)

    Barnes, Will Thomas; Cargill, Peter; Bradshaw, Stephen

    2016-05-01

    We use hydrodynamic modeling tools, including a two-fluid development of the EBTEL code, to investigate the properties expected of "hot" (i.e. between 106.7 and 107.2 K) non-flaring plasmas due to nanoflare heating in active regions. Here we focus on single nanoflares and show that while simple models predict an emission measure distribution extending well above 10 MK that is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium and, for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the "smoking gun" of nanoflare heating, lies between 1 MK and 10 MK. Signatures of the actual heating may be detectable in some instances.

  15. Self-assembled plasmonic core-shell clusters with an isotropic magnetic dipole response in the visible range.

    Science.gov (United States)

    Mühlig, Stefan; Cunningham, Alastair; Scheeler, Sebastian; Pacholski, Claudia; Bürgi, Thomas; Rockstuhl, Carsten; Lederer, Falk

    2011-08-23

    We theoretically analyze, fabricate, and characterize a three-dimensional plasmonic nanostructure that exhibits a strong and isotropic magnetic response in the visible spectral domain. Using two different bottom-up approaches that rely on self-organization and colloidal nanochemistry, we fabricate clusters consisting of dielectric core spheres, which are smaller than the wavelength of the incident radiation and are decorated by a large number of metallic nanospheres. Hence, despite having a complicated inner geometry, such a core-shell particle is sufficiently small to be perceived as an individual object in the far field. The optical properties of such complex plasmonic core-shell particles are discussed for two different core diameters.

  16. New insights into micro/nanoscale combined probes (nanoAuger, μXPS) to characterize Ag/Au@SiO2 core-shell assemblies.

    Science.gov (United States)

    Ledeuil, J B; Uhart, A; Soulé, S; Allouche, J; Dupin, J C; Martinez, H

    2014-10-01

    This work has examined the elemental distribution and local morphology at the nanoscale of core@shell Ag/Au@SiO2 particles. The characterization of such complex metal/insulator materials becomes more efficient when using an initial cross-section method of preparation of the core@shell nanoparticles (ion milling cross polisher). The originality of this route of preparation allows one to obtain undamaged, well-defined and planar layers of cross-cut nano-objects. Once combined with high-resolution techniques of characterization (XPS, Auger and SEM), the process appears as a powerful way to minimize charging effects and enhance the outcoming electron signal (potentially affected by the topography of the material) during analysis. SEM experiments have unambiguously revealed the hollow-morphology of the metal core, while Auger spectroscopy observations showed chemical heterogeneity within the particles (as silver and gold are randomly found in the core ring). To our knowledge, this is the first time that Auger nano probe spectroscopy has been used and successfully optimized for the study of some complex metal/inorganic interfaces at such a high degree of resolution (≈12 nm). Complementarily, XPS Au 4f and Ag 3d peaks were finally detected attesting the possibility of access to the whole chemistry of such nanostructured assemblies.

  17. Interaction of a C-terminal Truncated Hepatitis C Virus Core Protein with Plasmid DNA Vaccine Leads to in vitro Assembly of Heterogeneous Virus-like Particles

    Directory of Open Access Journals (Sweden)

    Nelson Acosta-Rivero

    2005-01-01

    Full Text Available Recently, it has been shown that HCV core proteins (HCcAg with C-terminal deletions assemble in vitro into virus-like particles (VLPs in the presence of structured RNA molecules. Results presented in this work showed that a truncated HCcAg variant covering the first 120 aa (HCcAg.120 with a 32 aa N-terminal fusion peptide (6xHistag-XpressTMepitope interacts with plasmid DNA vaccine. Interestingly, the buoyant density of VLPs containing HCcAg.120 in CsCl gradients changed from 1.15-1,17 g mLˉ1 to 1.30-1.34 g mLˉ1 after addition of plasmid DNA to assembly reactions. In addition, a delay in electrophoretic mobility of HCcAg.120-plasmid samples on agarose gels was observed indicating a direct interaction between VLPs and nucleic acids. Remarkably, addition of either plasmid DNA or tRNA to assembly reactions leaded to heterogeneous and larger VLPs formation than those observed in HCcAg.120 assembly reactions. VLPs containing HCcAg.120 induced a specific IgG antibodies in mice that reacted with hepatocytes from HCV-infected patients. VLPs obtained in this work would be important to elucidate the mechanisms behind the ability of HCcAg to assemble into a nucleocapsid structure. Besides, the capacity of particles containing HCcAg.120 to interact with nucleic acids could be used in the development of DNA vaccines and viral vectors based on these particles.

  18. Magnetically self-assembled SrFe12O19/Fe-Co core/shell particles

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X; Park, J; Hong, YK; Lane, AM

    2015-02-15

    Epitaxial growth to synthesize core/shell-structured materials is limited because large lattice mismatches are common between materials. Magnetically hard/soft, core/shell-structured materials can be potentially used for rare-earth free permanent magnets, but their synthesis presents a challenge. We report a wet chemistry method to synthesize core/shell structured particles consisting of a magnetically hard SrFe12O19 core and a soft Fe-Co shell, with a lattice mismatch of similar to 100%, which cannot be achieved by conventional epitaxial growth or other alternative methods. When decreasing the size of the magnetically soft Fe-Co nanoclusters to below 5 nm, we show that they can be magnetically attracted by the hard SrFe12O19 to form core/shell structured particles. An AC demagnetization experiment demonstrates the formation mechanism of the core/shell particles, and their magnetic hysteresis loop shows potential for use as rare-earth free permanent magnets. Published by Elsevier B.V.

  19. Additive manufacture (3d printing) of plasma diagnostic components and assemblies for fusion experiments

    Science.gov (United States)

    Sieck, Paul; Woodruff, Simon; Stuber, James; Romero-Talamas, Carlos; Rivera, William; You, Setthivoine; Card, Alexander

    2015-11-01

    Additive manufacturing (or 3D printing) is now becoming sufficiently accurate with a large range of materials for use in printing sensors needed universally in fusion energy research. Decreasing production cost and significantly lowering design time of energy subsystems would realize significant cost reduction for standard diagnostics commonly obtained through research grants. There is now a well-established set of plasma diagnostics, but these expensive since they are often highly complex and require customization, sometimes pace the project. Additive manufacturing (3D printing) is developing rapidly, including open source designs. Basic components can be printed for (in some cases) less than 1/100th costs of conventional manufacturing. We have examined the impact that AM can have on plasma diagnostic cost by taking 15 separate diagnostics through an engineering design using Conventional Manufacturing (CM) techniques to determine costs of components and labor costs associated with getting the diagnostic to work as intended. With that information in hand, we set about optimizing the design to exploit the benefits of AM. Work performed under DOE Contract DE-SC0011858.

  20. Layer-by-layer assembly of thin organic films on PTFE activated by cold atmospheric plasma

    Directory of Open Access Journals (Sweden)

    Tóth András

    2014-12-01

    Full Text Available An air diffuse coplanar surface barrier discharge is used to activate the surface of polytetrafluoroethylene (PTFE samples, which are subsequently coated with polyvinylpyrrolidone (PVP and tannic acid (TAN single, bi- and multilayers, respectively, using the dip-coating method. The surfaces are characterized by X-ray Photoelectron Spectroscopy (XPS, Attenuated Total Reflection – Fourier Transform Infrared Spectroscopy (ATR-FTIR and Atomic Force Microscopy (AFM. The XPS measurements show that with plasma treatment the F/C atomic ratio in the PTFE surface decreases, due to the diminution of the concentration of CF2 moieties, and also oxygen incorporation through formation of new C–O, C=O and O=C–O bonds can be observed. In the case of coated samples, the new bonds indicated by XPS show the bonding between the organic layer and the surface, and thus the stability of layers, while the gradual decrease of the concentration of F atoms with the number of deposited layers proves the creation of PVP/TAN bi- and multi-layers. According to the ATR-FTIR spectra, in the case of PVP/TAN multilayer hydrogen bonding develops between the PVP and TAN, which assures the stability of the multilayer. The AFM lateral friction measurements show that the macromolecular layers homogeneously coat the plasma treated PTFE surface.

  1. Tailor-made Au@Ag core-shell nanoparticle 2D arrays on protein-coated graphene oxide with assembly enhanced antibacterial activity

    Science.gov (United States)

    Wang, Huiqiao; Liu, Jinbin; Wu, Xuan; Tong, Zhonghua; Deng, Zhaoxiang

    2013-05-01

    Water-dispersible two-dimensional (2D) assemblies of Au@Ag core-shell nanoparticles are obtained through a highly selective electroless silver deposition on pre-assembled gold nanoparticles on bovine serum albumin (BSA)-coated graphene oxide (BSA-GO). While neither BSA-GO nor AuNP-decorated BSA-GO shows any antibacterial ability, the silver-coated GO@Au nanosheets (namely GO@Au@Ag) exhibit an enhanced antibacterial activity against Gram-negative Escherichia coli (E. coli) bacteria, superior to unassembled Au@Ag nanoparticles and even ionic Ag. Such an improvement may be attributed to the increased local concentration of silver nanoparticles around a bacterium and a polyvalent interaction with the bacterial surface. In addition, the colloidal stability of this novel nano-antimicrobial against the formation of random nanoparticle aggregates guarantees a minimized activity loss of the Au@Ag nanoparticles. The antibacterial efficacy of GO@Au@Ag is less sensitive to the existence of Cl-, in comparison with silver ions, providing another advantage for wound dressing applications. Our research unambiguously reveals a strong and very specific interaction between the GO@Au@Ag nanoassembly and E. coli, which could be an important clue toward a rational design, synthesis and assembly of innovative and highly active antibacterial nanomaterials.

  2. Additive Manufacture (3D Printing) of Plasma Diagnostic Components and Assemblies for Fusion Experiments

    Science.gov (United States)

    Quinley, Morgan; Chun, Katherine; Melnik, Paul; Sieck, Paul; Smith, Trevor; Stuber, James; Woodruff, Simon; Romero-Talamas, Carlos; Rivera, William; Card, Alexander

    2016-10-01

    We are investigating the potential impact of additive manufacturing (3D printing) on the cost and complexity of plasma diagnostics. We present a survey of the current state-of-the-art in additive manufacture of metals, as well as the design of diagnostic components that have been optimized for and take advantage of these processes. Included among these is a set of retarding field analyzer probe heads that have been printed in tungsten with internal heat sinks and cooling channels. Finite element analysis of these probe heads shows the potential for a 750K reduction in peak temperature, allowing the probe to take data twice as often without melting. Results of the evaluation of these probe heads for mechanical strength and outgassing, as well as their use on Alcator C-Mod will be presented. Supported by DOE SBIR Grant DE-SC0011858.

  3. Particulate Filtration from Emissions of a Plasma Pyrolysis Assembly Reactor Using Regenerable Porous Metal Filters

    Science.gov (United States)

    Agui, Juan H.; Abney, Morgan; Greenwood, Zachary; West, Philip; Mitchell, Karen; Vijayakumar, R.; Berger, Gordon M.

    2017-01-01

    Microwave-based plasma pyrolysis technology is being studied as a means of supporting oxygen recovery in future spacecraft life support systems. The process involves the conversion of methane produced from a Sabatier reactor to acetylene and hydrogen, with a small amount of solid carbon particulates generated as a side product. The particles must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on porous metal media filters for removing the carbon particulate emissions from the PPA exit gas stream and to provide in situ media regeneration capability. Because of the high temperatures involved in oxidizing the deposited carbon during regeneration, there was particular focus in this development on the materials that could be used, the housing design, and heating methods. This paper describes the design and operation of the filter and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC.

  4. Particulate filtration from emissions of a plasma pyrolysis assembly reactor using regenerable porous metal filters

    Science.gov (United States)

    Berger, Gordon M.; Agui, Juan H.; Vijayakumar, R.; Abney, Morgan B.; Greenwood, Zachary W.; West, Philip J.; Mitchell, Karen O.

    2017-01-01

    Microwave-based plasma pyrolysis technology is being studied as a means of supporting oxygen recovery in future spacecraft life support systems. The process involves the conversion of methane produced from a Sabatier reactor to acetylene and hydrogen, with a small amount of solid carbon particulates generated as a side product. The particles must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on porous metal media filters for removing the carbon particulate emissions from the PPA exit gas stream and to provide in situ media regeneration capability. Because of the high temperatures involved in oxidizing the deposited carbon during regeneration, there was particular focus in this development on the materials that could be used, the housing design, and heating methods. This paper describes the design and operation of the filter and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC.

  5. High-sensitive bioorthogonal SERS tag for live cancer cell imaging by self-assembling core-satellites structure gold-silver nanocomposite.

    Science.gov (United States)

    Chen, Meng; Zhang, Ling; Gao, Mingxia; Zhang, Xiangmin

    2017-09-01

    A novel, high-sensitivity, biocompatible SERS tag with core-shell structure based on gold nanoparticles containing alkynyl molecule core -silver nanoparticle satellites shell was fabricated for the first time to be used for live cancer cells Surface enhanced Raman scattering (SERS) imaging. (E)-2-((4-(phenylethynyl)benzylidene) amino) ethanethiol (PBAT) synthesized facilely in our lab is the Raman-silence region reporter which is advantage for bioorthogonal SERS cell imaging. In order to enhance the intensity of the Raman tags for live cancer cell imaging, a series of news measures have been adopted. Firstly, reporter molecules of the PBAT were added twice, which is embedded in the gold core with the reduction of tetrachloroaurate and then PBAT is conjugated again on disperse gold nanoparticles (PBAT-Au). Furthermore, numerous Ag nanoparticles self-assembly were densely arranged around PBAT-Au core surface (PBAT- Au@Ag), just like a circle of satellites cluster, which produce obvious "hot spots" effects enhancing the signal of the Raman tags enormously. Finally, Bovine serum albumin (BSA) and polydopamine (PDA) coated on the PBAT- Au@Ag successively, defined as (PBAT-Au@Ag@BSA@PDA), which make as-synthesized nanocomposites own features of bio-compatibility and facilitates antibody modification. Compared with Au@PBAT@PDA, PBAT-Au@Ag@BSA@PDA with core-shell satellites structure showed 10-fold increase in the Raman signals intensity. Moreover, PBAT-Au@Ag@BSA@PDA nanocomposites were successfully applied in the Raman imaging of human glioma cells (U251) by the recognition of the anti-epidermal growth factor receptor (EGFR). All experimental results demonstrated that the nanocomposites have high value and huge potential application in the live cancer cells imaging and biomedical diagnostics in the near future. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Interchange core/shell assembly of diluted magnetic semiconductor CeO2 and ferromagnetic ferrite Fe3O4 for microwave absorption

    Directory of Open Access Journals (Sweden)

    Jiaheng Wang

    2017-05-01

    Full Text Available Core/shell-structured CeO2/Fe3O4 and Fe3O4/CeO2 nanocapsules are prepared by interchange assembly of diluted magnetic semiconductor CeO2 and ferromagnetic ferrite Fe3O4 as the core and the shell, and vice versa, using a facile two-step polar solvothermal method in order to utilize the room-temperature ferromagnetism and abundant O-vacancies in CeO2, the large natural resonance in Fe3O4, and the O-vacancy-enhanced interfacial polarization between CeO2 and Fe3O4 for new generation microwave absorbers. Comparing to Fe3O4/CeO2 nanocapsules, the CeO2/Fe3O4 nanocapsules show an improved real permittivity of 3–10% and an enhanced dielectric resonance of 1.5 times at 15.3 GHz due to the increased O-vacancy concentration in the CeO2 cores of larger grains as well as the O-vacancy-induced enhancement in interfacial polarization between the CeO2 cores and the Fe3O4 shells, respectively. Both nanocapsules exhibit relatively high permeability in the low-frequency S and C microwave bands as a result of the bi-magnetic core/shell combination of CeO2 and Fe3O4. The CeO2/Fe3O4 nanocapsules effectively enhance permittivity and permeability in the high-frequency Ku band with interfacial polarization and natural resonance at ∼15 GHz, thereby improving absorption with a large reflection loss of -28.9 dB at 15.3 GHz. Experimental and theoretical comparisons with CeO2 and Fe3O4 nanoparticles are also made.

  7. Molybdate templated assembly of Ln12Mo4-type clusters (Ln = Sm, Eu, Gd) containing a truncated tetrahedron core.

    Science.gov (United States)

    Zheng, Yong; Zhang, Qian-Chong; Long, La-Sheng; Huang, Rong-Bin; Müller, Achim; Schnack, Jürgen; Zheng, Lan-Sun; Zheng, Zhiping

    2013-01-01

    Three heterometallic cluster complexes {Ln(12)Mo(4)} featuring an Ln(12) core of a distorted truncated tetrahedron were synthesized with the assistance of four MoO(4)(2-) anions as ancillary ligands. Magnetic studies of the {Gd(12)Mo(4)} cluster revealed a large magnetocaloric effect due to the presence of the large number of weakly coupled Gd(III) ions.

  8. Fabrication of a nanocarrier system through self-assembly of plasma protein and its tumor targeting

    Science.gov (United States)

    Gong, Guangming; Zhi, Feng; Wang, Kaikai; Tang, Xiaolei; Yuan, Ahu; Zhao, Lili; Ding, Dawei; Hu, Yiqiao

    2011-07-01

    Human serum albumin (HSA) nanoparticles hold great promise as a nanocarrier system for targeted drug delivery. The objective of this study was to explore the possibility of preparing size controllable albumin nanoparticles using the disulfide bond breaking reagent β-mercaptoethanol (β-ME). The results showed that the protein concentration and temperature had positive effects on the sizes of the albumin nanoparticles, while pH had a negative effect on the rate of nanoparticle formation. The addition of β-ME induced changes in HSA secondary structure and exposed the hydrophobic core of HSA, leading to the formation of nanoparticles. Human serum albumin nanoparticles could be internalized by MCF-7 cells and mainly accumulated in cytoplasm. After injection in tumor bearing mice, the HSA nanoparticles accumulated in tumor tissues, demonstrating the targeting ability of the nanoparticles. Therefore, human serum albumin can be fabricated into nanoparticles by breaking the disulfide bonds and these nanoparticles exhibit high tumor targeting ability. Human serum albumin nanoparticles could be ideal for the targeted delivery of pharmacologically active substances.

  9. Modified Bubble Core Fields and Bubble Shape in Laser Driven Plasma

    Institute of Scientific and Technical Information of China (English)

    WU Hai-Cheng; XIE Bai-Song

    2013-01-01

    Bubble core fields as well bubble shape modification due to the nondepleted electrons inside the bubble is investigated theoretically.It is found that the slope of transverse fields are reduced significantly,however,the slope of longitudinal electric field,which plays a key role on electrons acceleration in bubble,changes little.Moreover a modified longitudinal compressed bubble shape leads to a shorter dephasing distance which makes the electrons acceleration energy reduced to some extent.As a comparison we perform particle-in-cell simulations whose results are consistent with that of our theoretical consideration.

  10. Tungsten Micropowder/Copper Nanoparticle Core/Shell-Structured Composite Powder Synthesized by Inductively Coupled Thermal Plasma Process

    Science.gov (United States)

    Kim, Kyou-Hyun; Choi, Hanshin; Han, Chulwoong

    2017-01-01

    We here synthesized a Cu nanoparticle-coated W micropowder using in-situ reactive radio frequency thermal plasma with a blended feedstock of tungsten (W) and copper oxide micropowder. The spherical W micropowder improves the packing density and uniformity of the compacted body. On the other hand, the Cu nanoparticles coated on the W micropowder allow the spherical W powders to be compacted by rigid-die compaction only at 400 MPa. Moreover, homogeneous sintering in both solid state and liquid state occurs even at low Cu contents of 5 wt pct due to the uniformly coated Cu nanoparticles. The effect of W/Cu core/shell structure on the physical properties of sintered W-5 wt pct Cu composite is investigated based on the density, resistivity, and hardness. The results show that homogeneously sintered W-5 wt pct Cu composite well agree with the theoretical values calculated from the rule of mixture.

  11. Chain Assemblies from Nanoparticles Synthesized by Atmospheric Pressure Plasma Enhanced Chemical Vapor Deposition: The Computational View.

    Science.gov (United States)

    Mishin, Maxim V; Zamotin, Kirill Y; Protopopova, Vera S; Alexandrov, Sergey E

    2015-12-01

    This article refers to the computational study of nanoparticle self-organization on the solid-state substrate surface with consideration of the experimental results, when nanoparticles were synthesised during atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD). The experimental study of silicon dioxide nanoparticle synthesis by AP-PECVD demonstrated that all deposit volume consists of tangled chains of nanoparticles. In certain cases, micron-sized fractals are formed from tangled chains due to deposit rearrangement. This work is focused on the study of tangled chain formation only. In order to reveal their formation mechanism, a physico-mathematical model was developed. The suggested model was based on the motion equation solution for charged and neutral nanoparticles in the potential fields with the use of the empirical interaction potentials. In addition, the computational simulation was carried out based on the suggested model. As a result, the influence of such experimental parameters as deposition duration, particle charge, gas flow velocity, and angle of gas flow was found. It was demonstrated that electrical charges carried by nanoparticles from the discharge area are not responsible for the formation of tangled chains from nanoparticles, whereas nanoparticle kinetic energy plays a crucial role in deposit morphology and density. The computational results were consistent with experimental results.

  12. Synergistic Effect of Cold Atmospheric Plasma and Drug Loaded Core-shell Nanoparticles on Inhibiting Breast Cancer Cell Growth.

    Science.gov (United States)

    Zhu, Wei; Lee, Se-Jun; Castro, Nathan J; Yan, Dayun; Keidar, Michael; Zhang, Lijie Grace

    2016-01-01

    Nano-based drug delivery devices allowing for effective and sustained targeted delivery of therapeutic agents to solid tumors have revolutionized cancer treatment. As an emerging biomedical technique, cold atmospheric plasma (CAP), an ionized non-thermal gas mixture composed of various reactive oxygen species, reactive nitrogen species, and UV photons, shows great potential for cancer treatment. Here we seek to develop a new dual cancer therapeutic method by integrating promising CAP and novel drug loaded core-shell nanoparticles and evaluate its underlying mechanism for targeted breast cancer treatment. For this purpose, core-shell nanoparticles were synthesized via co-axial electrospraying. Biocompatible poly (lactic-co-glycolic acid) was selected as the polymer shell to encapsulate anti-cancer therapeutics. Results demonstrated uniform size distribution and high drug encapsulation efficacy of the electrosprayed nanoparticles. Cell studies demonstrated the effectiveness of drug loaded nanoparticles and CAP for synergistic inhibition of breast cancer cell growth when compared to each treatment separately. Importantly, we found CAP induced down-regulation of metastasis related gene expression (VEGF, MTDH, MMP9, and MMP2) as well as facilitated drug loaded nanoparticle uptake which may aid in minimizing drug resistance-a major problem in chemotherapy. Thus, the integration of CAP and drug encapsulated nanoparticles provides a promising tool for the development of a new cancer treatment strategy.

  13. Double core-hole spectroscopy of transient plasmas produced in the interaction of ultraintense x-ray pulses with neon

    CERN Document Server

    Gao, Cheng; Yuan, Jianmin

    2015-01-01

    Double core-hole (DCH) spectroscopy is investigated systematically for neon atomic system in the interaction with ultraintense x-ray pulses with photon energy from 937 eV to 2000 eV. A time-dependent rate equation, implemented in the detailed level accounting approximation, is utilized to study the dynamical evolution of the level population and emission properties of the highly transient plasmas. For x-ray pulses with photon energy in the range of 937-1030 eV, where $1s\\rightarrow 2p$ resonance absorption from single core-hole (SCH) states of neon charge states exist, inner-shell resonant absorption (IRA) effects play important roles in the time evolution of population and DCH spectroscopy. Such IRA physical effects are illustrated in detail by investigating the interaction of x-ray pulses at a photon energy of 944 eV, which corresponds to the $1s\\rightarrow 2p$ resonant absorption from the SCH states ($1s2s^22p^4$, $1s2s2p^5$ and $1s2p^6$) of Ne$^{3+}$. After averaging over the space and time distribution o...

  14. A relay mechanism between EB1 and APC facilitate STIM1 puncta assembly at endoplasmic reticulum-plasma membrane junctions.

    Science.gov (United States)

    Asanov, Alexander; Sherry, Ryan; Sampieri, Alicia; Vaca, Luis

    2013-09-01

    The assembly of STIM1 protein puncta near endoplasmic reticulum-plasma membrane (ER-PM) junctions is required for optimal activation of store-operated channels (SOC). The mechanisms controlling the translocation of STIM1 puncta to ER-PM junctions remain largely unknown. In the present study, we have explored the role of the microtubule binding protein adenomatous polyposis coli (APC), on STIM1 puncta and store-operated calcium entry (SOCE). APC-depleted cells showed reduced STIM1 puncta near ER-PM junctions, instead puncta is found at the ER surrounding the cell nucleus. Reduced STIM1 puncta near ER-PM junctions in APC-depleted cells correlates with a strong inhibition of SOCE and diminished Orai whole-cell currents. Immunoprecipitation and confocal microscopy co-localization studies indicate that, upon depletion of the ER, STIM1 dissociates from EB1 and associates to APC. Deletion analysis identified an APC-binding domain in the carboxyl terminus of STIM1 (STIM1 650-685). These results together position APC as an important element in facilitating the translocation of STIM1 puncta near ER-PM junctions, which in turn is required for efficient SOCE and Orai activation upon depletion of the ER. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Self-assembly and graft polymerization route to Monodispersed Fe3O4@SiO2--polyaniline core-shell composite nanoparticles: physical properties.

    Science.gov (United States)

    Reddy, Kakarla Raghava; Lee, Kwang-Pill; Kim, Ju Young; Lee, Youngil

    2008-11-01

    This study describes the synthesis of monodispersed core-shell composites of silica-modified magnetic nanoparticles and conducting polyaniline by self-assembly and graft polymerization. Magnetic ferrite nanoparticles (Fe3O4) were prepared by coprecipitation of Fe+2 and Fe+3 ions in alkaline solution, and then silananized. The silanation of magnetic particles (Fe3O4@SiO2) was carried out using 3-bromopropyltrichlorosilane (BPTS) as the coupling agent. FT-IR spectra indicated the presence of Fe--O--Si chemical bonds in Fe3O4@SiO2. Core-shell type nanocomposites (Fe3O4@SiO2/PANI) were prepared by grafting polyaniline (PANI) on the surface of silanized magnetic particles through surface initiated in-situ chemical oxidative graft polymerization. The nanocomposites were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Fourier transform infrared (FTIR) spectra, UV-visible spectroscopy, photoluminescence (PL) spectra, electrical conductivity and magnetic characteristics. HRTEM images of the nanocomposites revealed that the silica-modified magnetic particles made up the core while PANI made up the shell. The XPS spectrum revealed the presence of silica in the composites, and the XRD results showed that the composites were more crystalline than pure PANI. PL spectra show that composites exhibit photoluminescent property. Conductivity of the composites (6.2 to 9.4 x 10(-2) S/cm) was higher than that of pristine PANI (3.7 x 10(-3) S/cm). The nanocomposites exhibited superparamagnetism. Formation mechanism of the core-shell structured nanocomposites and the effect of modified magnetic nanoparticles on the electro-magnetic properties of the Fe3O4@SiO2/PANI nanocomposites are also investigated. This method provides a new strategy for the generation of multi-functional nanocomposites that composed of other conducting polymers and metal nanoparticles.

  16. Understanding the core density profile in TCV H-mode plasmas

    CERN Document Server

    Wágner, Dávid; Pitzschke, Andreas; Sauter, Olivier; Weisen, Henri

    2012-01-01

    Results from a database analysis of H-mode electron density profiles on the Tokamak \\`a Configuration Variable (TCV) in stationary conditions show that the logarithmic electron density gradient increases with collisionality. By contrast, usual observations of H-modes showed that the electron density profiles tend to flatten with increasing collisionality. In this work it is reinforced that the role of collisionality alone, depending on the parameter regime, can be rather weak and in these, dominantly electron heated TCV cases, the electron density gradient is tailored by the underlying turbulence regime, which is mostly determined by the ratio of the electron to ion temperature and that of their gradients. Additionally, mostly in ohmic plasmas, the Ware-pinch can significantly contribute to the density peaking. Qualitative agreement between the predicted density peaking by quasi-linear gyrokinetic simulations and the experimental results is found. Quantitative comparison would necessitate ion temperature meas...

  17. In-Core Fuel Managements for PWRs: Investigation on solution for optimal utilization of PWR fuel through the use of fuel assemblies with differently enriched {sup 235}U fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Caprioli, Sara

    2004-04-01

    A possibility for more efficient use of the nuclear fuel in a pressurized water reactor is investigated. The alternative proposed here consists of the implementation of PWR fuel assemblies with differently enriched {sup 235}U fuel pins. This possibility is examined in comparison with the standard assembly design. The comparison is performed both in terms of single assembly performance and in the terms of nuclear reactor core performance and fuel utility. For the evaluation of the actual performance of the new assembly types, 5 operated fuel core sequences of R3 (Ringhals' third unit), for the period 1999 - 2004 (cycles 17 - 21) were examined. For every cycle, the standard fresh fuel assemblies have been identified and taken as reference cases for the study of the new type of assemblies with differently enriched uranium rods. In every cycle, assemblies with and without burnable absorber are freshly loaded into the core. The axial enrichment distribution is kept uniform, allowing for a radial (planar) enrichment level distribution only. At an assembly level, it has been observed that the implementation of the alternative enrichment configuration can lead to lower and flatter internal peaking factor distribution with respect to the uniformly enriched reference assemblies. This can be achieved by limiting the enrichment levels distribution to a rather narrow range. The highest enrichment level chosen has the greatest impact on the power distribution of the assemblies. As it increases, the enrichment level drives the internal peaking factor to greater values than in the reference assemblies. Generally, the highest enrichment level that would allow an improvement in the power performance of the assembly lies between 3.95 w/o and 4.17 w/o. The highest possible enrichment level depends on the average enrichment of the overall assembly, which is kept constant to the average enrichment of the reference assemblies. The improvements that can be obtained at this level are

  18. A Key to Improved Ion Core Confinement in the JET Tokamak: Ion Stiffness Mitigation due to Combined Plasma Rotation and Low Magnetic Shear

    DEFF Research Database (Denmark)

    Mantica, P.; Challis, C.; Peeters, A.G.

    2011-01-01

    New transport experiments on JET indicate that ion stiffness mitigation in the core of a rotating plasma, as described by Mantica et al. Phys. Rev. Lett. 102 175002 (2009)] results from the combined effect of high rotational shear and low magnetic shear. The observations have important implicatio...

  19. Multilayer core-shell structured composite paper electrode consisting of copper, cuprous oxide and graphite assembled on cellulose fibers for asymmetric supercapacitors

    Science.gov (United States)

    Wan, Caichao; Jiao, Yue; Li, Jian

    2017-09-01

    An easily-operated and inexpensive strategy (pencil-drawing-electrodeposition-electro-oxidation) is proposed to synthesize a novel class of multilayer core-shell structured composite paper electrode, which consists of copper, cuprous oxide and graphite assembled on cellulose fibers. This interesting electrode structure plays a pivotal role in providing more active sites for electrochemical reactions, facilitating ion and electron transport and shorting their diffusion pathways. This electrode demonstrates excellent electrochemical properties with a high specific capacitance of 601 F g-1 at 2 A g-1 and retains 83% of this capacitance when operated at an ultrahigh current density of 100 A g-1. In addition, a high energy density of 13.4 W h kg-1 at the power density of 0.40 kW kg-1 and a favorable cycling stability (95.3%, 8000 cycles) were achieved for this electrode. When this electrode was assembled into an asymmetric supercapacitor with carbon paper as negative electrode, the device displays remarkable electrochemical performances with a large areal capacitances (122 mF cm-2 at 1 mA cm-2), high areal energy density (10.8 μW h cm-2 at 402.5 μW cm-2) and outstanding cycling stability (91.5%, 5000 cycles). These results unveil the potential of this composite electrode as a high-performance electrode material for supercapacitors.

  20. Perfect Fluidity of the Quark Gluon Plasma Core as Seen through its Dissipative Hadronic Corona

    CERN Document Server

    Hirano, T; Hirano, Tetsufumi; Gyulassy, Miklos

    2006-01-01

    The agreement of hydrodynamic predictions of differential elliptic flow and radial flow patterns with Au+Au data is one of the main lines of evidence suggesting the nearly perfect fluid properties of the strongly coupled Quark Gluon Plasma, sQGP, produced at RHIC. We study the sensitivity of this conclusion to different hydrodynamic assumptions on chemical and thermal freezeout after the sQGP hadronizes. We show that if chemical freezeout occurs at the hadronization time, the differential elliptic flow for pions increase with proper time in the late hadronic phase until thermal freezeout and leads to a discrepancy with the data. In contrast, if both chemical and thermal equilibrium are maintained past the hadronization, then the mean pT per pion increases in a way that accidentally preserves v2(pT) from the sQGP phase in agreement with the data, but at the cost of the agreement with the hadronic yields. In order that all the data on hadronic ratios, radial flow, and differential elliptic flow be reproduced, t...

  1. In-Core Fuel Managements for PWRs: Investigation on solution for optimal utilization of PWR fuel through the use of fuel assemblies with differently enriched {sup 235}U fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Caprioli, Sara

    2004-04-01

    A possibility for more efficient use of the nuclear fuel in a pressurized water reactor is investigated. The alternative proposed here consists of the implementation of PWR fuel assemblies with differently enriched {sup 235}U fuel pins. This possibility is examined in comparison with the standard assembly design. The comparison is performed both in terms of single assembly performance and in the terms of nuclear reactor core performance and fuel utility. For the evaluation of the actual performance of the new assembly types, 5 operated fuel core sequences of R3 (Ringhals' third unit), for the period 1999 - 2004 (cycles 17 - 21) were examined. For every cycle, the standard fresh fuel assemblies have been identified and taken as reference cases for the study of the new type of assemblies with differently enriched uranium rods. In every cycle, assemblies with and without burnable absorber are freshly loaded into the core. The axial enrichment distribution is kept uniform, allowing for a radial (planar) enrichment level distribution only. At an assembly level, it has been observed that the implementation of the alternative enrichment configuration can lead to lower and flatter internal peaking factor distribution with respect to the uniformly enriched reference assemblies. This can be achieved by limiting the enrichment levels distribution to a rather narrow range. The highest enrichment level chosen has the greatest impact on the power distribution of the assemblies. As it increases, the enrichment level drives the internal peaking factor to greater values than in the reference assemblies. Generally, the highest enrichment level that would allow an improvement in the power performance of the assembly lies between 3.95 w/o and 4.17 w/o. The highest possible enrichment level depends on the average enrichment of the overall assembly, which is kept constant to the average enrichment of the reference assemblies. The improvements that can be obtained at this level are

  2. The features of neutronic calculations for fast reactors with hybrid cores on the basis of BFS-62-3A critical assembly experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mitenkova, E. F.; Novikov, N. V. [Nuclear Safety Inst. of Russian Academy of Sciences, B. Tulskaya 52, Moscow, 115119 (Russian Federation); Blokhin, A. I. [State Scientific Center of Russian Federation, Inst. of Physics and Power Engineering Named after A.I. Leypunsky, Bondarenko Square 1, Obninsk, Kaluga Region, 249030 (Russian Federation)

    2012-07-01

    The different (U-Pu) fuel compositions are considered for next generation of sodium fast breeder reactors. The considerable discrepancies in axial and radial neutron spectra for hybrid reactor systems compared to the cores with UO{sub 2} fuel cause increasing uncertainty of generating the group nuclear constants in those reactor systems. The calculation results of BFS-62-3A critical assembly which is considered as full-scale model of BN-600 hybrid core with steel reflector specify quite different spectra in local areas. For those systems the MCNP 5 calculations demonstrate significant sensitivity of effective multiplication factor K{sub eff} and spectral indices to nuclear data libraries. For {sup 235}U, {sup 238}U, {sup 239}Pu the results of calculated radial fission rate distributions against the reconstructed ones are analyzed. Comparative analysis of spectral indices, neutron spectra and radial fission rate distributions are performed using the different versions of ENDF/B, JENDL-3.3, JENDL-4, JEFF-3.1.1 libraries and BROND-3 for Fe, Cr isotopes. For analyzing the fission rate sensitivity to the plutonium presence in the fuel {sup 239}Pu is substituted for {sup 235}U (enrichment 90%) in the FA areas containing the plutonium. For {sup 235}U, {sup 238}U, {sup 239}Pu radial fission rate distributions the explanation of pick values discrepancies is based on the group fission constants analyses and possible underestimation of some features at the experimental data recovery method (Westcott factors, temperature dependence). (authors)

  3. Single and double core-hole ion emission spectroscopy of transient neon plasmas produced by ultraintense x-ray laser pulses

    Science.gov (United States)

    Gao, Cheng; Zeng, Jiaolong; Yuan, Jianmin

    2016-05-01

    Single core-hole (SCH) and double core-hole (DCH) spectroscopy is investigated systematically for neon gas in the interaction with ultraintense x-ray pulses with photon energy from 937 eV to 2000 eV. A time-dependent rate equation, implemented in the detailed level accounting approximation, is utilized to study the dynamical evolution of the level population and emission properties of the laser-produced highly transient plasmas. The plasma density effects on level populations are demonstrated with an x-ray photon energy of 2000 eV. For laser photon energy in the range of 937 - 1360 eV, resonant absorptions (RA) of 1s-np (n> = 2) transitions play important roles in time evolution of the population and DCH emission spectroscopy. For x-ray photon energy larger than 1360 eV, no RA exist and transient plasmas show different features in the DCH spectroscopy.

  4. Aquaregia and Oxygen Plasma Treatments on Fluorinated Tin Oxide for Assembly of PLEDs Devices Using OC1C10-PPV as Emissive Polymer

    Directory of Open Access Journals (Sweden)

    Emerson Roberto SANTOS

    2009-02-01

    Full Text Available In this work were carried out treatments with oxygen plasma and aquaregia on fluorinated tin oxide (FTO films varying the treatment times. After treatments, the samples were analyzed by techniques measurements: sheet resistance, thickness, Hall effect, transmittance and superficial roughness. Devices using FTO/PEDOT:PSS/OC1C10-PPV/Al were assembled. In this experiment some variations were observed by sheet resistance and thickness and Hall effect measurements indicated most elevated carriers concentration and resistivity for aquaregia than that oxygen plasma. The roughness was elevated for the first minutes with treatment by aquaregia too. In the I-V curves the aquaregia devices presented the lowest threshold voltage for 30 minutes and devices treated by oxygen plasma presented a behavior most resistivity different of typical curves for PLEDs devices.

  5. Self-assembled amphiphilic core-shell nanocarriers in line with the modern strategies for brain delivery.

    Science.gov (United States)

    Elezaby, Reham S; Gad, Heba A; Metwally, Abdelkader A; Geneidi, Ahmed S; Awad, Gehanne A

    2017-09-10

    Disorders of the central nervous system (CNS) represent increasing social and economic problems all over the world which makes the effective transport of drugs to the brain a crucial need. In the last decade, many strategies were introduced to deliver drugs to the brain trying to overcome the challenge of the blood brain barrier (BBB) using both invasive and non-invasive methods. Non-invasive strategy represented in the application of nanocarriers became very common. One of the most hopeful nanoscopic carriers for brain delivery is core-shell nanocarriers or polymeric micelles (PMs). They are more advantageous than other nanocarriers. They offer small size, ease of preparation, ease of sterilization and the possibility of surface modification with various ligands. Hence, the aim of this review is to discuss modern strategies for brain delivery, micelles as a successful delivery system for the brain and how micelles could be modified to act as "magic bullets" for brain delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Modeling and design of a new core-moderator assembly and neutron beam ports for the Penn State Breazeale Nuclear Reactor (PSBR)

    Science.gov (United States)

    Ucar, Dundar

    This study is for modeling and designing a new reactor core-moderator assembly and new neutron beam ports that aimed to expand utilization of a new beam hall of the Penn State Breazeale Reactor (PSBR). The PSBR is a part of the Radiation Science and Engineering Facility (RSEC) and is a TRIGA MARK III type research reactor with a movable core placed in a large pool and is capable to produce 1MW output. This reactor is a pool-type reactor with pulsing capability up to 2000 MW for 10-20 msec. There are seven beam ports currently installed to the reactor. The PSBR's existing core design limits the experimental capability of the facility, as only two of the seven available neutron beam ports are usable. The finalized design features an optimized result in light of the data obtained from neutronic and thermal-hydraulics analyses as well as geometrical constraints. A new core-moderator assembly was introduced to overcome the limitations of the existing PSBR design, specifically maximizing number of available neutron beam ports and mitigating the hydrogen gamma contamination of the neutron beam channeled in the beam ports. A crescent-shaped moderator is favored in the new PSBR design since it enables simultaneous use of five new neutron beam ports in the facility. Furthermore, the crescent shape sanctions a coupling of the core and moderator, which reduces the hydrogen gamma contamination significantly in the new beam ports. A coupled MURE and MCNP5 code optimization analysis was performed to calculate the optimum design parameters for the new PSBR. Thermal-hydraulics analysis of the new design was achieved using ANSYS Fluent CFD code. In the current form, the PSBR is cooled by natural convection of the pool water. The driving force for the natural circulation of the fluid is the heat generation within the fuel rods. The convective heat data was generated at the reactor's different operating powers by using TRIGSIMS, the fuel management code of the PSBR core. In the CFD

  7. Determination of Ar Concentration Evolution Within DIII-D Core Plasma by X-ray Ross Filter Method

    Science.gov (United States)

    Bogatu, I. N.; Edgell, D. H.; Brooks, N. H.; Snider, R. T.; West, W. P.; Wade, M. R.

    2001-10-01

    Injection of the non-recycling noble gas Ar into the DIII-D divertor is a promising technique for reducing the heat load on the plates; it also seems to improve thermal transport in an advanced operating mode. During such experiments core plasma contamination by migrating Ar can be investigated by measuring the evolution of the Ar concentration profile using the Ross filter method implemented on the fan shaped X-ray poloidal diagnostics on DIII-D. A Ross filter with energy pass band centered on the ArXVII K_α line at 3.14 keV, discriminating Ar K_α line against background radiation, was used on DIII-D. A high sensitivity to the injected quantity of Ar and good discrimination against Ne was observed. We present reconstruction of Ar concentration profiles from the chord-integrated measurements using the measured Te and ne profiles. Using the transport code MIST, the impurity diffusion coefficients can be determined by matching the time evolution of the Ar concentration evolution.

  8. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. II. Nanoflare Trains

    CERN Document Server

    Barnes, W T; Bradshaw, S J

    2016-01-01

    Despite its prediction over two decades ago, the detection of faint, high-temperature ("hot") emission due to nanoflare heating in non-flaring active region cores has proved challenging. Using an efficient two-fluid hydrodynamic model, this paper investigates the properties of the emission expected from repeating nanoflares (a nanoflare train) of varying frequency as well as the separate heating of electrons and ions. If the emission measure distribution ($\\mathrm{EM}(T)$) peaks at $T = T_m$, we find that $\\mathrm{EM}(T_m)$ is independent of details of the nanoflare train, and $\\mathrm{EM}(T)$ above and below $T_m$ reflects different aspects of the heating. Below $T_m$ the main influence is the relationship of the waiting time between successive nanoflares to the nanoflare energy. Above $T_m$ power-law nanoflare distributions lead to an extensive plasma population not present in a monoenergetic train. Furthermore, in some cases characteristic features are present in $\\mathrm{EM}(T)$. Such details may be detec...

  9. Characterisation of LMD virus-like nanoparticles self-assembled from cationic liposomes, adenovirus core peptide mu and plasmid DNA.

    Science.gov (United States)

    Tagawa, T; Manvell, M; Brown, N; Keller, M; Perouzel, E; Murray, K D; Harbottle, R P; Tecle, M; Booy, F; Brahimi-Horn, M C; Coutelle, C; Lemoine, N R; Alton, E W F W; Miller, A D

    2002-05-01

    Liposome:mu:DNA (LMD) is a ternary nucleic acid delivery system built around the mu peptide associated with the condensed core complex of the adenovirus. LMD is prepared by precondensing plasmid DNA (D) with mu peptide (M) in a 1:0.6 (w/w) ratio and then combining these mu:DNA (MD) complexes with extruded cationic liposomes (L) resulting in a final lipid:mu:DNA ratio of 12:0.6:1 (w/w/w). Correct buffer conditions, reagent concentrations and rates of mixing are all crucial to success. However, once optimal conditions are established, homogeneous LMD particles (120 +/- 30 nm) will result that each appear to comprise an MD particle encapsulated within a cationic bilammellar liposome. LMD particles can be formulated reproducibly, they are amenable to long-term storage (>1 month) at -80 degrees C and are stable to aggregation at a plasmid DNA concentration up to 5 mg/ml (15 mM nucleotide concentration). Furthermore, LMD transfections are significantly more time and dose efficient in vitro than cationic liposome-plasmid DNA (LD) transfections. Transfection times as short as 10 min and plasmid DNA doses as low as 0.001 microg/well result in significant gene expression. LMD transfections will also take place in the presence of biological fluids (eg up to 100% serum) giving 15-25% the level of gene expression observed in the absence of serum. Results from confocal microscopy experiments using fluorescent-labelled LMD particles suggest that endocytosis is not a significant barrier to LMD transfection, although the nuclear membrane still is. We also confirm that topical lung transfection in vivo by LMD is at least equal in absolute terms with transfection mediated by GL-67:DOPE:DMPE-PEG(5000) (1:2:0.05 m/m/m), an accepted 'gold-standard' non-viral vector system for topical lung transfection, and is in fact at least six-fold more dose efficient. All these features make LMD an important new non-viral vector platform system from which to derive tailor-made non-viral delivery

  10. Comparative analysis of core heat transport of JET high density H-mode plasmas in carbon wall and ITER-like wall

    Science.gov (United States)

    Kim, Hyun-Tae; Romanelli, M.; Voitsekhovitch, I.; Koskela, T.; Conboy, J.; Giroud, C.; Maddison, G.; Joffrin, E.; contributors, JET

    2015-06-01

    A consistent deterioration of global confinement in H-mode experiments has been observed in JET [1] following the replacement of all carbon plasma facing components (PFCs) with an all metal (‘ITER-like’) wall (ILW). This has been correlated to the observed degradation of the pedestal confinement, as lower electron temperature (Te) values are routinely measured at the top of the edge barrier region. A comparative investigation of core heat transport in JET-ILW and JET-CW (carbon wall) discharges has been performed, to assess whether core confinement has also been affected by the wall change. The results presented here have been obtained by analysing a set of discharges consisting of high density JET-ILW H-mode plasmas and comparing them against their counterpart discharges in JET-CW having similar global operational parameters. The set contains 10 baseline ({βN}=1.5∼ 2 ) discharge-pairs with 2.7 T toroidal magnetic field, 2.5 MA plasma current, and 14 to 17 MW of neutral beam injection (NBI) heating. Based on a Te profile analysis using high resolution Thomson scattering (HRTS) data, the Te profile peaking (i.e. core Te (ρ = 0.3) / edge Te (ρ = 0.7)) is found to be similar, and weakly dependent on edge Te, for both JET-ILW and JET-CW discharges. When ILW discharges are seeded with N2, core and edge Te both increase to maintain a similar peaking factor. The change in core confinement is addressed with interpretative TRANSP simulations. It is found that JET-ILW H-mode plasmas have higher NBI power deposition to electrons and lower NBI power deposition to ions as compared to the JET-CW counterparts. This is an effect of the lower electron temperature at the top of the pedestal. As a result, the core electron energy confinement time is reduced in JET-ILW discharges, but the core ion energy confinement time is not decreased. Overall, the core energy confinement is found to be the same in the JET-ILW discharges compared to the JET-CW counterparts.

  11. Influence of Oxygenated Compounds on Reaction Products in a Microwave Plasma Methane Pyrolysis Assembly for Post-Processing of Sabatier Methane

    Science.gov (United States)

    Mansell, J. Matthew; Abney, Morgan B.

    2012-01-01

    The state-of-the-art Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS) in April 2010. The system is designed to accept carbon dioxide from the Carbon Dioxide Removal Assembly and hydrogen from the Oxygen Generation Assembly. The two gases are reacted in the CRA in a Sabatier reactor to produce water and methane. Venting of methane results in an oxygen resupply requirement of about 378 lbs per crew member per year. If the oxygen is supplied as water, the total weight for resupply is about 476 lb per crew member per year. For long-term missions beyond low Earth orbit, during which resupply capabilities will be further limited, recovery of hydrogen from methane is highly desirable. For this purpose, NASA is pursuing development of a Plasma Pyrolysis Assembly (PPA) capable of recovering hydrogen from methane. Under certain conditions, water vapor and carbon dioxide (nominally intended to be separated from the CRA outlet stream) may be present in the PPA feed stream. Thus, testing was conducted in 2010 to determine the effect of these oxygenated compounds on PPA performance, particularly the effect of inlet carbon dioxide and water variations on the PPA product stream. This paper discusses the test set-up, analysis, and results of this testing.

  12. Fe3O4@ZnO core-shell nanocomposites for efficient and repetitive removal of low density lipoprotein in plasma and on blood vessel

    Science.gov (United States)

    Huang, Xiao; Lu, Juan; Yue, Danyang; Fan, Yijuan; Yi, Caixia; Wang, Xiaoying; Zhang, Mengxue; Pan, Jun

    2015-03-01

    Low density lipoprotein (LDL)-apheresis therapy, which directly removes LDL from plasma by LDL-adsorbents in vitro is found to be clinically effective and safe to lower the LDL content in blood to prevent cardiovascular disease. Thus, developing excellent LDL adsorbents are becoming more and more attractive. Herein, functional Fe3O4@ZnO core-shell nanocomposites have been synthesized by a facile and eco-friendly two-step method. Not only do they possess high LDL adsorption (in PBS/plasma as well as on blood vessels) and favorable magnetic targeting ability but they can also be reused conveniently, which offer the Fe3O4@ZnO core-shell nanocomposites significant potential in the removal of LDL in vitro and in vivo.

  13. Synthesis and Relaxivity Studies of a DOTA-Based Nanomolecular Chelator Assembly Supported by an Icosahedral Closo-B122− -Core for MRI: A Click Chemistry Approach

    Directory of Open Access Journals (Sweden)

    Satish S. Jalisatgi

    2013-07-01

    Full Text Available An icosahedral closo-B122− scaffold based nano-sized assembly capable of carrying a high payload of Gd3+-chelates in a sterically crowded configuration is developed by employing the azide-alkyne click reaction. The twelve copies of DO3A-t-Bu-ester ligands were covalently attached to an icosahedral closo-B122− core via suitable linkers through click reaction. This nanomolecular structure supporting a high payload of Gd3+-chelate is a new member of the closomer MRI contrast agents that we are currently developing in our laboratory. The per Gd ion relaxivity (r1 of the newly synthesized MRI contrast agent was obtained in PBS, 2% tween/PBS and bovine calf serum using a 7 Tesla micro MRI instrument and was found to be slightly higher (r1 = 4.7 in PBS at 25 °C compared to the clinically used MRI contrast agents Omniscan (r1 = 4.2 in PBS at 25 °C and ProHance (r1 = 3.1 in PBS at 25 °C.

  14. Significance of the hepatitis C virus (HCV core antigen as an alternative plasma marker of active HCV infection

    Directory of Open Access Journals (Sweden)

    Daniel HDJ

    2007-01-01

    Full Text Available Purpose: To evaluate the role of core antigen (Ortho trak-C assay as a marker of active HCV infection in comparison to HCV RNA as detected by reverse transcription polymerase chain reaction (RT-PCR. Methods: This evaluation was carried out during January 2000 to December 2003 in HCV infected individuals who were treatment naοve or were on anti-viral therapy. Additionally, sequential plasma samples from patients on clinical follow-up were included in this study. A total of 167 samples from 61 patients were tested by trak-C and RT-PCR. HCV RNA detection was achieved by a RT-PCR. Trak-C assay results were also compared in a limited proportion of these samples with known HCV viral load and genotype. Results: Of 167 samples tested, 56.9% were RNA positive and 43.1% were RNA negative while 50.3% were trak-C positive and 49.7% were trak-C negative, yielding a sensitivity of 85.3% and a specificity of 95.8% for the trak-C assay (Kappa co-efficient = 0.8. The concentration of HCVcAg and HCV RNA showed significant correlation (n=38, r=0.334, P =0.04. The trak-C assay detected the most prevalent HCV genotypes in India without significant difference ( P =0.335. The difference between mean absorbance values of HCV RNA positive samples compared to HCV RNA negative samples in the trak-C assay was highly significant ( P < 0.000. Qualitative results of trak-C assay and RT-PCR were comparable in 93% of follow-up samples. Conclusions: Trak-C assay can be recommended for confirmation of HCV infection and follow-up in laboratories with resource-poor facilities.

  15. Modelling the influence of temperature anisotropies on poloidal asymmetries of density in the core of rotating plasmas

    Science.gov (United States)

    Bilato, R.; Maj, O.; Angioni, C.

    2014-07-01

    A consistent set of equations is derived to model poloidal density asymmetries induced by temperature anisotropies in tokamak rotating plasmas. The model can be applied to compute poloidal density asymmetry of highly charged impurities due to additional plasma heating.

  16. Formularization of the confinement enhancement factor as a function of the heating profile for FFHR-d1 core plasma design

    Science.gov (United States)

    Miyazawa, J.; Goto, T.; Sakamoto, R.; Motojima, G.; Suzuki, C.; Funaba, H.; Morisaki, T.; Masuzaki, S.; Yamada, I.; Murakami, S.; Suzuki, Y.; Yokoyama, M.; Peterson, B. J.; Yamada, H.; Sagara, A.; the FFHR Design Group

    2012-12-01

    A quantitative estimation of the confinement enhancement due to the heating profile effect is introduced to the helical fusion DEMO reactor design of FFHR-d1, based on the experimental results of the Large Helical Device. By applying this to the direct profile extrapolation (DPE) method, radial profiles in the reactor are extrapolated from experimental results. In reactor plasmas, the heat deposition profile of alpha heating is expected to be peaked in the core region as in the case of tangential neutral beam (NB) injection on low-density plasmas. The height of the pressure profile normalized by the gyro-Bohm-type parameter dependence increases with the power (˜0.6) of the peaking factor of the heat deposition profile, as long as the core confinement degradation observed in low-density plasmas is ignored. According to this observation, the confinement enhancement factor expected under the self-ignition condition ranges from ˜1.1 to ˜1.7, for example, depending on the used data. Degradation of the global energy confinement observed in high-density NB-heated plasmas is mitigated and the gyro-Bohm-type parameter dependence reappears after introducing the confinement enhancement due to the heating profile effect. Finally, typical example profiles in FFHR-d1 are provided by the DPE method for future analyses.

  17. Adaptive mutations enhance assembly and cell-to-cell transmission of a high-titer hepatitis C virus genotype 5a Core-NS2 JFH1-based recombinant

    DEFF Research Database (Denmark)

    Mathiesen, Christian K; Prentoe, Jannick; Meredith, Luke W

    2015-01-01

    UNLABELLED: Recombinant hepatitis C virus (HCV) clones propagated in human hepatoma cell cultures yield relatively low infectivity titers. Here, we adapted the JFH1-based Core-NS2 recombinant SA13/JFH1C3405G,A3696G (termed SA13/JFH1orig), of the poorly characterized genotype 5a, to Huh7.5 cells......81-deficient Huh7-derived cells demonstrated that these changes did not affect replication but increased HCV assembly and specific infectivity as early as 24 h posttransfection. Infectious coculture assays in Huh7.5 cells showed a significant increase in cell-to-cell transmission for SA13/JFH1Core...

  18. 核电厂反应堆堆芯中子与温度探测器组件研制%Design of In-Core Neutron and Temperature Detector Assembly for Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    黄国良

    2014-01-01

    针对ACP1000堆型,研制了用于反应堆堆芯核测系统的堆芯中子和温度测量探测器组件。文介绍了探测器组件的设计、性能指标和试验结果。设计的堆芯中子和温度探测器组件集成了中子自给能探测器和测温元件并固定安装在堆内。试验结果表明测量敏感元件的性能满足设计要求,外壳和密封组件能保证反应堆一回路压力边界的要求。堆芯测量探测器组件一体化的设计可提高安全性和可靠性,实现实时测量,可用于反应堆保护。%For the ACP1000 reactor type , the detector assembly of measuring in -core neutron and temperature for reactor in-core nuclear detection system is designed .This article introduces the design , capability and ex-perimental results of this detector assembly .Detector assembly for measuring in -core neutron and temperature integrates self -powered neutron detectors and temperature measuring components and install them inside the reactor .Results indicate that the capability of sensitive components meets the design requirements , and shell and sealing assembly can meet the requirements of reactor loop pressure boundary .Integration of in -core measuring systems can improve the security and reliability , can achieve real -time measurements and can be used for reactor protection .

  19. Development of a high dynamic range spectroscopic system for observation of neutral hydrogen atom density distribution in Large Helical Device core plasma

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K., E-mail: fujii@me.kyoto-u.ac.jp; Atsumi, S.; Watanabe, S.; Shikama, T.; Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 606-8540 (Japan); Goto, M.; Morita, S. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2014-02-15

    We report development of a high dynamic range spectroscopic system comprising a spectrometer with 30% throughput and a camera with a low-noise fast-readout complementary metal-oxide semiconductor sensor. The system achieves a 10{sup 6} dynamic range (∼20 bit resolution) and an instrumental function approximated by a Voigt profile with Gauss and Lorentz widths of 31 and 0.31 pm, respectively, for 656 nm light. The application of the system for line profile observations of the Balmer-α emissions from high temperature plasmas generated in the Large Helical Device is also presented. In the observed line profiles, emissions are detected in far wings more than 1.0 nm away from the line center, equivalent to neutral hydrogen atom kinetic energies above 1 keV. We evaluate atom density distributions in the core plasma by analyzing the line profiles.

  20. Enhancement of magnetic coercivity and macroscopic quantum tunneling in monodispersed Co/CoO cluster assemblies

    OpenAIRE

    Peng, D. L.; Sumiyama, Kenji; Hihara, Takehiko; Yamamuro, S.; ヒハラ, タケヒコ; スミヤマ, ケンジ; 日原, 岳彦; 隅山, 兼治; Hihara, T.; Sumiyama, K.

    1999-01-01

    Magnetic properties have been measured for monodisperse-sized Co/CoO cluster assemblies prepared by a plasma-gas-condensation-type cluster beam deposition technique. The clear correlation obtained between exchange bias field and coercivity suggests the enhancement of uniaxial anisotropy owing to the exchange coupling between the ferromagnetic Co core and antiferromagnetic CoO shell, and magnetic disorder at the core-shell interface. A nonthermal magnetic relaxation observed below 8 K, being r...

  1. HINODE/EIS SPECTROSCOPIC VALIDATION OF VERY HOT PLASMA IMAGED WITH THE SOLAR DYNAMICS OBSERVATORY IN NON-FLARING ACTIVE REGION CORES

    Energy Technology Data Exchange (ETDEWEB)

    Testa, Paola [Smithsonian Astrophysical Observatory, 60 Garden street, MS 58, Cambridge, MA 02138 (United States); Reale, Fabio, E-mail: ptesta@cfa.harvard.edu [Dipartimento di Fisica, Universita di Palermo, Piazza del Parlamento 1, 90134 Palermo (Italy)

    2012-05-01

    We use coronal imaging observations with the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), and Hinode/Extreme-ultraviolet Imaging Spectrometer (EIS) spectral data to explore the potential of narrowband EUV imaging data for diagnosing the presence of hot (T {approx}> 5 MK) coronal plasma in active regions. We analyze observations of two active regions (AR 11281, AR 11289) with simultaneous AIA imaging and EIS spectral data, including the Ca XVII line (at 192.8 A), which is one of the few lines in the EIS spectral bands sensitive to hot coronal plasma even outside flares. After careful co-alignment of the imaging and spectral data, we compare the morphology in a three-color image combining the 171, 335, and 94 A AIA spectral bands, with the image obtained for Ca XVII emission from the analysis of EIS spectra. We find that in the selected active regions the Ca XVII emission is strong only in very limited areas, showing striking similarities with the features bright in the 94 A (and 335 A) AIA channels and weak in the 171 A band. We conclude that AIA imaging observations of the solar corona can be used to track hot plasma (6-8 MK), and so to study its spatial variability and temporal evolution at high spatial and temporal resolution.

  2. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. I. Single Nanoflares

    Science.gov (United States)

    Barnes, W. T.; Cargill, P. J.; Bradshaw, S. J.

    2016-09-01

    The properties that are expected of “hot” non-flaring plasmas due to nanoflare heating in active regions are investigated using hydrodynamic modeling tools, including a two-fluid development of the Enthalpy Based Thermal Evolution of Loops code. Here we study a single nanoflare and show that while simple models predict an emission measure distribution extending well above 10 MK, which is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium, and for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the “smoking gun” of nanoflare heating, lies between 106.6 and 107 K. Signatures of the actual heating may be detectable in some instances.

  3. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores I. Single Nanoflares

    CERN Document Server

    Barnes, W T; Bradshaw, S J

    2016-01-01

    The properties expected of "hot" non-flaring plasmas due to nanoflare heating in active regions are investigated using hydrodynamic modeling tools, including a two-fluid development of the EBTEL code. Here we study a single nanoflare and show that while simple models predict an emission measure distribution extending well above 10 MK that is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium and, for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the "smoking gun" of nanoflare heating, lies between $10^{6.6}$ and $10^7$ K. Signatures of the actual heating may be detectable in some instances.

  4. Ion-plasma nitriding of austenitic steel in a low-pressure low-frequency inductive discharge with ferrite core

    Science.gov (United States)

    Isupov, M. V.; Pinaev, V. A.; Mul, D. O.; Belousova, N. S.

    2017-05-01

    An experimental investigation of ion-plasma nitriding of austenitic stainless steel AISI 321 in a low-frequency (100 kHz) nitrogen inductive discharge has been performed for the nitrogen pressure of 7 Pa, nitrogen ion densities of 1010-1011 cm-3, sample temperatures of 440-590 °C, the densities of current on the sample surface of 1.2-3.3 mA/cm2, sample biases of -500 and -750 V. The time of ion-plasma treatment was 20 and 60 min. It is shown that even for the short (20 min.) ion-plasma treatment in the low-frequency inductive discharge, formation of nitrided layers with the thickness of up to 40 μm and microhardness of up to 9 GPa is observed.

  5. Evaluation of the antifouling and photocatalytic properties of poly(vinylidene fluoride) plasma-grafted poly(acrylic acid) membrane with self-assembled TiO2.

    Science.gov (United States)

    You, Sheng-Jie; Semblante, Galilee Uy; Lu, Shao-Chung; Damodar, Rahul A; Wei, Ta-Chin

    2012-10-30

    Immobilization of TiO(2) is a promising approach that produces antifouling and photocatalytic membranes that could help advance wastewater treatment and re-use processes. In this study, poly(acrylic acid) (PAA) was plasma-grafted on commercial poly(vinylidene fluoride) (PVDF) to introduce functional groups on the membrane surface that can support the nanoparticles. It was found that plasma treatment at 100 W for 120 s followed by liquid grafting with 70% aqueous AA at 60°C for 2h maximized the number of TiO(2) binding sites. Membrane hydrophilicity was tremendously enhanced by the self-assembly of TiO(2), following a direct proportionality to TiO(2) loading. The membrane with 0.5% TiO(2) loading maintained the highest pure water flux and the best protein antifouling property. UV irradiation triggered the photodegradation of strongly bound foulants, but at least 1.5% TiO(2) and 30 min cumulative irradiation were necessary to completely recover the membrane's original performance. The TiO(2)-modified membranes removed 30-42% of 50mg/l aqueous Reactive Black 5 (RB5) dye. The fabricated membranes demonstrate huge potential for use in membrane reactors with high hydrophilicity, fouling mitigation, and photocatalytic capability.

  6. Seismic behaviour of fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Song, Heuy Gap; Jhung, Myung Jo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1993-11-01

    A general approach for the dynamic time-history analysis of the reactor core is presented in this paper as a part of the fuel assembly qualification program. Several detailed core models are set up to reflect the placement of the fuel assemblies within the core shroud. Peak horizontal responses are obtained for each model for the motions induced from earthquake. The dynamic responses such as fuel assembly shear force, bending moment and displacement, and spacer grid impact loads are carefully investigated. Also, the sensitivity responses are obtained for the earthquake motions and the fuel assembly non-linear response characteristics are discussed. (Author) 9 refs., 24 figs., 1 tab.

  7. Glycosylphosphatidyl Inositol-anchored Proteins and fyn Kinase Assemble in Noncaveolar Plasma Membrane Microdomains Defined by Reggie-1 and -2

    OpenAIRE

    Stürmer, Claudia; Lang, Dirk M.; Kirsch, Friederike; Wiechers, Marianne F.; Deininger, Sören-Oliver; Plattner, Helmut

    2001-01-01

    Using confocal laser scanning and double immunogold electron microscopy, we demonstrate that reggie-1 and -2 are colocalized in ≤0.1-μm plasma membrane microdomains of neurons and astrocytes. In astrocytes, reggie-1 and -2 do not occur in caveolae but clearly outside these structures. Microscopy and coimmunoprecipitation show that reggie-1 and -2 are associated with fyn kinase and with the glycosylphosphatidyl inositol-anchored proteins Thy-1 and F3 that, when activated by antibody cross-link...

  8. Integrated magnetic transformer assembly

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to an integrated magnetics transformer assembly comprising a first magnetically permeable core forming a first substantially closed magnetic flux path and a second magnetically permeable core forming a second substantially closed magnetic flux path. A first input...... inductor winding is wound around a first predetermined segment of the first magnetically permeable core and a second input inductor winding is wound around a first predetermined segment of the second magnetically permeable core. The integrated magnetics transformer assembly further comprises a first output......-winding of the first output inductor winding and the first half-winding of the second output inductor winding are configured to produce aligned, i.e. in the same direction, magnetic fluxes through the first substantially closed magnetic flux path. The integrated magnetics transformer assembly is well- suited for use...

  9. Synthesis of core-fluorescent four-armed star and dicyclic 8-shaped poly(THF)s by electrostatic self-assembly and covalent fixation (ESA–CF) protocol

    KAUST Repository

    Fujiwara, Susumu

    2013-12-07

    A pair of four-armed star and dicyclic 8-shaped poly(tetrahydrofuran)s, poly(THF)s, possessing a perylene diimide group at the core position (Ia and Ib, respectively) were synthesized by means of an electrostatic self-assembly and covalent fixation (ESA–CF) protocol. Mono- and bifunctional poly(THF)s having N-phenylpiperidinium salt end groups accompanying a perylene diimide tetracarboxylate as a counteranion were prepared by the ion-exchange reaction, and the subsequent covalent conversion by reflux in toluene afforded the corresponding core-fluorescent four-armed star and dicyclic 8-shaped poly(THF)s, (Ia and Ib, respectively) for the use of single-molecule fluorescence microscopy measurements.

  10. Comparison between different flux traps assembled in the core of the nuclear reactor IPEN/MB-01 by measuring of the thermal and epithermal neutron fluxes using activation foils

    Energy Technology Data Exchange (ETDEWEB)

    Mura, Luiz Ernesto Credidio; Bitelli, Ulysses d' Utra; Mura, Luis Felipe Liambos; Carluccio, Thiago; Andrade, Graciete Simoes de, E-mail: ubitelli@ipen.b, E-mail: gsasilva@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The production of radioisotopes is one of the most important applications of nuclear research reactors. This study investigated a method called Flux Trap, which is used to increase the yield of production of radioisotopes in nuclear reactors. The method consists in the rearrangement of the fuel rods to allow the increase of the thermal neutron flux in the irradiation region inside the reactor core, without changing the standard reactor power level. Various configurations were assembled with the objective of finding the configuration with the highest thermal neutron flux in the region of irradiation. The method of activation analysis was used to measure the thermal neutron flux and determine the most efficient reactor core configuration . It was found that there was an increase in the thermal neutron flux of 337% in the most efficient configuration, which demonstrates the effectiveness of the method. (author)

  11. Restricted access magnetic core-mesoporous shell microspheres with C8-modified interior pore-walls for the determination of diazepam in rat plasma by LC-MS.

    Science.gov (United States)

    Liu, Xiaodan; Yu, Yingjia; Li, Yan; Ning, Suli; Liu, Tingting; Li, Fajie; Duan, Gengli

    2013-03-15

    In this study, a novel enrichment technique based on magnetic core-mesoporous shell microspheres with C8-modified interior pore-walls (C8-Fe₃O₄@mSiO₂) was successfully developed for the determination of diazepam in rat plasma by LC-MS. Due to the unique properties of the synthesized C8-Fe₃O₄@mSiO₂ microspheres (C8-modified magnetic mesoporous microsphere), small drug molecules like diazepam can enter the mesopore channels and be efficiently absorbed through hydrophobic interaction by interior C8-groups (Octyl functional groups). Large molecules like proteins are excluded from the mesopore channels as a result of size exclusion effect, leading to direct extraction of drug molecules from protein-rich biosmaples such as plasma without any other pretreatment procedure. Moreover, diazepam adsorbed C8-Fe₃O₄@mSiO₂ microspheres could be simply and rapidly isolated through placing a magnet on the bottom of container, and then diazepam could be easily eluted from C8-Fe₃O₄@mSiO₂ microspheres for further LC-MS analysis. Extraction conditions such as amounts of C8-Fe₃O₄@mSiO₂ microspheres added, adsorption time, elution solvent and elution time were investigated. Method validations including linear range, the limit of detection, precision, and recovery were also studied. The results indicated that the proposed method based on C8-Fe₃O₄@mSiO₂ microspheres was simple and accurate for the analysis of diazepam in the rat plasma. And it will provide new ideas for analyzing plasma concentration and pharmacokinetics of similar drugs.

  12. Hysteresis of fluctuation dynamics associated with a fireball in a magnetized glow discharge plasma in a currentless toroidal assembly

    Science.gov (United States)

    Ghosh, Sabuj; Shaw, Pankaj Kumar; Saha, Debajyoti; Janaki, M. S.; Sekar Iyengar, A. N.

    2016-09-01

    Floating potential fluctuations associated with an anode fireball in a glow discharge plasma in the toroidal vacuum vessel of the SINP tokamak are found to exhibit different kinds of oscillations under the action of vertical magnetic field of different strengths. While increasing the vertical magnetic field, the fluctuations have shown transitions as: chaotic oscillation → inverse homoclinic transition → intermittency → chaotic oscillation. However, on decreasing the magnetic field, the fluctuations are seen to follow: chaotic oscillations → homoclinic transition → chaotic oscillation; that is the intermittent feature is not observed. Fireball dynamics is found to be closely related to the magnetic field applied; results of visual inspection with a high speed camera are in close agreement with the fluctuations, and the fireball dynamics is found to be closely related to the transitions. The statistical properties like skewness, kurtosis, and entropy of the fluctuations are also found to exhibit this hysteresis behaviour.

  13. Supercontinuum generation in the vacuum ultraviolet through dispersive-wave and soliton-plasma interaction in a noble-gas-filled hollow-core photonic crystal fiber

    Science.gov (United States)

    Ermolov, A.; Mak, K. F.; Frosz, M. H.; Travers, J. C.; Russell, P. St. J.

    2015-09-01

    We report on the generation of a three-octave-wide supercontinuum extending from the vacuum ultraviolet (VUV) to the near infrared, spanning at least 113-1000 nm (i.e., 11 -1.2 eV ), in He-filled hollow-core kagome-style photonic crystal fiber. Numerical simulations confirm that the main mechanism is an interaction between dispersive-wave emission and plasma-induced blue-shifted soliton recompression around the fiber zero dispersion frequency. The VUV part of the supercontinuum, the modeling of which proves to be coherent and possesses a simple phase structure, has sufficient bandwidth to support single-cycle pulses of 500 asec duration. We also demonstrate, in the same system, the generation of narrower-band VUV pulses through dispersive-wave emission, tunable from 120 to 200 nm with efficiencies exceeding 1 % and VUV pulse energies in excess of 50 nJ.

  14. Reaction mechanism of core-shell MoO2/MoS2 nanoflakes via plasma-assisted sulfurization of MoO3

    Science.gov (United States)

    Kumar, Prabhat; Singh, Megha; Sharma, Rabindar K.; Reddy, G. B.

    2016-05-01

    The sulfurization of MoO3 in an H2S/Ar plasma atmosphere has been experimentally studied and a reaction mechanism has been proposed based on the results obtained. Nanostructured thin films (NTFs) of MoO3 were sulfurized at different temperatures varying from 150 °C to 550 °C. High-resolution transmission electron microscopy (TEM) images depict core-shell nanoflakes with varying shell thicknesses as the sulfurization temperature (T sn) is varied. The shells consist of MoS2 and the core is MoO2/MoO3. X-ray diffraction (XRD) and Raman analysis have been used to study the structural changes as MoO3 is sulfurized. The analyses showed two phases, MoO2 and MoS2, at low temperatures (≤350 °C), whereas the films sulfurized at higher temperatures show predominantly MoS2. The scanning electron microscopy (SEM) results show no noticeable changes in the surface morphology of the NTFs after sulfurization. X-ray photoelectron spectroscopy (XPS) was carried out to calculate the relative percentages of MoO3, MoO2 and MoS2. It is revealed that sulfurization of MoO3 in the plasma is affected by T sn. The sulfurization process occurs in two steps, involving the reduction of MoO3 to form MoO2 in the first step, followed by MoO2 being converted into MoS2. It is also evident that the reduction of MoO3 is more a result of the reactive species of hydrogen (H*) than the replacement of oxygen by sulfur in the second step.

  15. Core-shell iron oxide-layered double hydroxide: High electrochemical sensing performance of H2O2 biomarker in live cancer cells with plasma therapeutics.

    Science.gov (United States)

    Asif, Muhammad; Liu, Hongwei; Aziz, Ayesha; Wang, Haitao; Wang, Zhengyun; Ajmal, Muhammad; Xiao, Fei; Liu, Hongfang

    2017-11-15

    In this work, we develop a new type of multifunctional core-shell nanomaterial by controllable integration of CuAl layered double hydroxides (LDHs) over the surface of iron oxides (Fe3O4) nanospheres (NSs) to fabricate (Fe3O4@CuAl NSs) hybrid material with interior tunability of LDH phase and explore its practical application in ultrasensitive detection of emerging biomarker, i.e., H2O2 as cancer diagnostic probe. In addition, atmospheric pressure plasmas (APPs) have also been used as potential therapeutic approach for cancer treatment. Due to the synergistic combination of p-type semiconductive channels of LDHs with multi-functional properties, unique morphology and abundant surface active sites, the Fe3O4@CuAl NSs modified electrode exhibited attractive electrocatalytic activity towards H2O2 reduction. Under the optimized conditions, the proposed biosensor demonstrated striking electrochemical sensing performances to H2O2 including linear range as broad as 8 orders of magnitude, low real detection limit of 1nM (S/N = 3), high sensitivity, good reproducibility and long-term stability. Arising from the superb efficiency, the electrochemical biosensor has been used for in vitro determination of H2O2 concentrations in human urine and serum samples prior to and following the intake of coffee, and real-time monitoring of H2O2 efflux from different cancer cell lines in normal state and after plasma treatment. We believe that this novel nano-platform of structurally integrated core-shell nanohybrid materials combined with APPs will enhance diagnostic as well as therapeutic window for cancer diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Concept Design of Supercritical Water Cooled Reactor Core with Double-Row-Rod Assemblies%双排棒组件超临界水堆堆芯方案设计

    Institute of Scientific and Technical Information of China (English)

    杨珏; 张勇; 赵传奇; 单建强; 王飞; 曹良志

    2012-01-01

    结合国际上多种超临界水堆堆芯设计方案的优点,提出了一种新的压力容器式低泄漏堆芯设计方案,其特点是,堆芯中采用了双排棒正方形闭式燃料组件和三区低泄漏换料.双排棒燃料组件由两排燃料棒包围一个慢化剂水棒构成,可以使得慢化均匀;三区低泄漏换料可以大大延长堆芯寿期,降低压力容器快中子注量.通过堆芯三维物理热工耦合计算发现,该方案寿期内的最大包壳温度(MCST)为684℃,堆芯寿期为300个有效满功率天,且功率分布平坦.在此基础上,对所有组件进行了更为保守的子通道热工水力计算,得出MCST为685.3℃,进一步表明所提堆芯设计方案在物理热工方面是可行的.%A new pressure-vessel type supercritical water cooled reactor (SCWR) core concept was proposed by combining merits of several SCWR core designs in the world. This core design employs a new type of closed assembly with double-row fuel rods in square geometry and a three-batch low-leakage refueling scheme. The assembly consists of two rows of fuel rods and a moderator rod, which causes the moderation more uniform. The three-batch low leakage refueling scheme obviously increases the cycle length and reduces the neutron fluence on the pressure vessel. Three-dimensional neutronics/thermohydraulics coupling calculation shows that the maximum cladding surface temperature (MCST) is 684 ℃, the cycle life is 300 effective full power days and the power distribution is flat. Then the more conservative sub-channel analysis was performed for all fuel assemblies. The MCST was evaluated to be 685. 3 ℃, showing that the core design is feasible.

  17. Hydrogen storage and hydrolysis properties of core-shell structured Mg-MFx (M=V, Ni, La and Ce) nano-composites prepared by arc plasma method

    Science.gov (United States)

    Mao, Jianfeng; Zou, Jianxin; Lu, Chong; Zeng, Xiaoqin; Ding, Wenjiang

    2017-10-01

    In this work, core-shell structured Mg-MFx (M = V, Ni, La and Ce) nano-composites are prepared by using arc plasma method. The particle size distribution, phase components, microstructures, hydrogen sorption properties of these composites and hydrolysis properties of their corresponding hydrogenated powders are carefully investigated. It is shown that the addition of MFx through arc plasma method can improve both the hydrogen absorption kinetics of Mg and the hydrolysis properties of corresponding hydrogenated powders. Among them, the Mg-NiF2 composite shows the best hydrogen absorption properties at relatively low temperatures, which can absorb 3.26 wt% of H2 at 373 K in 2 h. Such rapid hydrogen absorption rate is mainly due to the formation of Mg2Ni and MgF2 on Mg particles during arc evaporation and condensation. In contrast, measurements also show that the hydrogenated Mg-VF3 composite has the lowest peak desorption temperature and the fastest hydrolysis rate among all the hydrogenated Mg-MFx composites. The less agglomeration tendency of Mg particles and VO2 covered on MgH2 particles account for the reduced hydrogen desorption temperature and enhanced hydrolysis rate.

  18. Control Rod Ejection Accident while Using 6- and 8-Tube IRT-4M Fuel Assemblies in WWR-SM Research Reactor Core

    Energy Technology Data Exchange (ETDEWEB)

    Baytelesov, S.; Kungurov, F.; Safarov, A.; Salikhbaev, U.

    2011-07-01

    The WWR-SM reactor at the Institute of Nuclear Physics of the Academy of Sciences (INP AS) in Uzbekistan was converted to 6-tube IRT-4M LEU (19.7%) fuel in 2009. Presently, INP intends to also use IRT-4M 8-tube FA, and a safety analysis for these 'mixed' (8-tube and 6-tube FA) cores is required by the regulatory authorities. This paper presents results of control rod ejection transient analysis for these mixed cores

  19. Production and application of push-pull cable core for automobile control cable assembly%汽车控制索总成用推拉索索芯的生产及应用

    Institute of Scientific and Technical Information of China (English)

    张晓

    2013-01-01

    推拉索索芯是汽车控制索总成中的关键,其性能直接影响控制索总成的疲劳寿命.以1 +12-3.2索芯为例介绍索芯的生产及应用.索芯外层采用Φ0.60 mm的70钢丝,抗拉强度1770~1960 MPa,锌层面质量不小于60 g/m2;中心采用Φ2.0 mm的65 Mn钢丝,抗拉强度1670~1870 MPa,扭转、弯曲分别不小于18次、9次,断面收缩率不小于45%,金相组织为回火马氏体.捻制工艺参数:预变形器中心距19 mm,交换牙齿数比39∶56,收线力矩电机电压250~ 300 V,并采用在线光整以及在线轧制与锻打相结合的工艺技术,可批量、连续稳定地生产面接触钢丝绳.提出索芯在应用中的注意事项.%Push-pull cable core is key of automobile control cable assembly, its property impacts the fatigue life of control cable assembly directly. To take 1+12?. 2 cable core as an example, the production and application of cable core is introduced. Cable core outer layer adopts diameter 0.60 mm 70 steel wire, tensile strength is 1 770 ~ 1 960 MPa, zinc coat mass in no less than 60 g/m , cable core wire adopts diameter 2.0 mm 65 Mn steel wire, tensile strength is 1 670 ~ 1 870 MPa, torsion and bending are no less than 18,9 times respectively, area reduction is no less than 45% , microstructure is tempered martensite. Stranding process control parameters are as follows: predeformation apparatus center distance is 19 mm, exchange gear ratio is 39: 56, take-up torque motor voltage is 250 ~ 300 V. The process technology of online finishing, online rolling and forging combination is adopted, surface contact wire rope can be produced in quantity and continuous stable. The matters needing attention of application are proposed.

  20. Cellulose nanofiber/nanocrystal reinforced capsules: a fast and facile approach toward assembly of liquid-core capsules with high mechanical stability.

    Science.gov (United States)

    Svagan, Anna J; Musyanovych, Anna; Kappl, Michael; Bernhardt, Max; Glasser, Gunnar; Wohnhaas, Christian; Berglund, Lars A; Risbo, Jens; Landfester, Katharina

    2014-05-12

    Liquid-core capsules of high mechanical stability open up for many solid state-like applications where functionality depending on liquid mobility is vital. Herein, a novel concept for fast and facile improvement of the mechanical properties of walls of liquid-core capsules is reported. By imitating nature's own way of enhancing the mechanical properties in liquid-core capsules, the parenchyma plant cells found in fruits and vegetables, a blend of short cellulose nanofibers (capsule walls. The NFC/CNC blend was prepared from a new version of the classical wood pulp hydrolysis. The capsule shell consisted of a covalently (by aromatic diisocyanate) cross-linked NFC/CNC structure at the outer capsule wall and an inner layer dominated by aromatic polyurea. The mechanical properties revealed an effective capsule elastic modulus of 4.8 GPa at 17 wt % NFC/CNC loading, about six times higher compared to a neat aromatic polyurea capsule (0.79 GPa) and 3 orders of magnitude higher than previously reported capsules from regenerated cellulose (0.0074 GPa). The outstanding mechanical properties are ascribed to the dense nanofiber structure, present in the outer part of the capsule wall, that is formed by oriented NFC/CNC of high average aspect ratio (L/d ∼ 70) and held together by both covalent (urethane bonds) and physical bonds (hydrogen bonds).

  1. Analysis of the Gas Core Actinide Transmutation Reactor (GCATR)

    Science.gov (United States)

    Clement, J. D.; Rust, J. H.

    1977-01-01

    Design power plant studies were carried out for two applications of the plasma core reactor: (1) As a breeder reactor, (2) As a reactor able to transmute actinides effectively. In addition to the above applications the reactor produced electrical power with a high efficiency. A reactor subsystem was designed for each of the two applications. For the breeder reactor, neutronics calculations were carried out for a U-233 plasma core with a molten salt breeding blanket. A reactor was designed with a low critical mass (less than a few hundred kilograms U-233) and a breeding ratio of 1.01. The plasma core actinide transmutation reactor was designed to transmute the nuclear waste from conventional LWR's. The spent fuel is reprocessed during which 100% of Np, Am, Cm, and higher actinides are separated from the other components. These actinides are then manufactured as oxides into zirconium clad fuel rods and charged as fuel assemblies in the reflector region of the plasma core actinide transmutation reactor. In the equilibrium cycle, about 7% of the actinides are directly fissioned away, while about 31% are removed by reprocessing.

  2. The preparation of composite microsphere with hollow core/porous shell structure by self-assembling of latex particles at emulsion droplet interface.

    Science.gov (United States)

    He, Xiao Dong; Ge, Xue Wu; Wang, Mo Zhen; Zhang, Zhi Cheng

    2006-07-15

    A submicrometer-scaled polystyrene/melamine-formaldehyde hollow microsphere composite was prepared by self-assembling of sulfonated polystyrene (SPS) latex particles at the interface of emulsion droplets and then being fixed in place using a hard melamine-formaldehyde (MF) composite layer. For control-released purposes, the influential factors that control the size and uniformity of the packed-droplets and the permeability of the composite shell, including the initial particle location, the hydrophilicity and the size of colloidal templates, the oil phase solvent and reserving time of emulsions after the addition of MF prepolymer, were further studied. Relatively uniform sized particle packed-droplets with an average diameter of 10 microm were obtained. The assembled SPS particles kept ordering and minimal conglutination after the preparation of composite microspheres, which allows of controlling the permeability from the interstices between the particles. Porous-mesh-structured MF composite layer was formed to further control the permeability. The morphology of emulsions and composite microspheres were characterized by optical microscopy, scanning and transmission electron microscopy.

  3. Fuel Management Study on PWR Core Included of 157 Fuel Assemblies%157组燃料组件组成的堆芯燃料管理研究

    Institute of Scientific and Technical Information of China (English)

    姚红

    2013-01-01

    The fuel management of the PWR reactor core reload optimization was studied with SCIENCE codes in the paper ,the PWR core consists of 157 fuel assemblies .The paper studied five strategies ,three strategies are one-year reload and the other two are 18-month reload strategies .The main results of the eight cycles for the five strategies were given ,and the results were compared with each other .In conclusion ,the power peak of the OU T-IN strategy loading pattern is lower ,and the power peak of the IN-OU T loading pattern is higher ,but all of them are satisfied with design limitation .The average discharge burnup of the quarter core strategy is the highest ,which means that the assemblies of this strategy are burned the most sufficiently , so the economic efficiency of the quarter core strategy is the best .%本文应用SCIENCE程序包对157组燃料组件组成的压水堆堆芯进行换料优化燃料管理研究,给出了3个年换料和2个18个月换料共5个设计方案,每个设计方案给出了从首循环到第8循环共8个循环的主要计算结果,并进行了分析比较。综合来看,OUT-IN装载的设计方案功率峰值偏低,IN-OUT装载的设计方案功率峰值偏高,但均在设计限值以内;1/4堆芯换料设计方案的平均卸料燃耗最深,表明其组件燃耗得最充分,经济性较好。

  4. Marshall N. Rosenbluth Outstanding Doctoral Thesis Award Talk: Simultaneous Measurement of Electron Temperature and Density Fluctuations in the Core of DIII-D Plasmas

    Science.gov (United States)

    White, A. E.

    2009-11-01

    Multi-field fluctuation measurements provide opportunities for rigorous comparison between experiment and nonlinear gyrokinetic turbulence simulations. A unique set of diagnostics on DIII-D allows for simultaneous study of local, long-wavelength (0 < kθρs< 0.5) electron temperature and density fluctuations in the core plasma (0.4 < ρ< 0.8). Previous experiments in L-mode indicate that normalized electron temperature fluctuation levels (40 < f < 400,kHz) increase with radius from ˜0.4% at ρ= 0.5 to ˜2% at ρ=0.8, similar to simultaneously measured density fluctuations. Electron cyclotron heating (ECH) is used to increase Te, which increases electron temperature fluctuation levels and electron heat transport in the experiments. In contrast, long wavelength density fluctuation levels change very little. The different responses are consistent with increased TEM drive relative to ITG-mode drive. A new capability at DIII-D is the measurement of phase angle between electron temperature and density fluctuations using coupled correlation electron cyclotron emission radiometer and reflectometer diagnostics. Linear and nonlinear GYRO runs have been used to design validation experiments that focus on measurements of the phase angle. GYRO shows that if Te and ∇Te increase 50% in a beam-heated L-mode plasma (ρ=0.5), then the phase angle between electron temperature and density fluctuations decreases 30%-50% and electron temperature fluctuation levels increase a factor of two more than density fluctuations. Comparisons between these predictions and experimental results will be presented.

  5. Mass spectrometry and photoelectron spectroscopy of o-, m-, and p-terphenyl cluster anions: the effect of molecular shape on molecular assembly and ion core character.

    Science.gov (United States)

    Mitsui, Masaaki; Ando, Naoto; Nakajima, Atsushi

    2008-06-26

    Mass spectrometry and photoelectron spectroscopy of o-, m-, and p-terphenyl cluster anions, (o-TP)n(-) (n = 2-100), (m-TP)n(-) (n = 2-100), and (p-TP)n(-) (n = 1-100), respectively, are conducted to investigate the effect of molecular shape on the molecular aggregation form and the resultant ion core character of the clusters. For (o-TP)n(-) and (m-TP)n(-), neither magic numbers nor discernible isomers are observed throughout the size range. Furthermore, their vertical detachment energies (VDEs) increase up to large n and depend linearly on n(-1/3), implying that they possess a three-dimensional (3D), highly reorganized structure encompassing a monomeric anion core. For (p-TP)n(-), in contrast, prominent magic numbers of n = 5, 7, 10, 12, and 14 are observed, and the VDEs show pronounced irregular shifts below n = 10, while they remain constant above n = 14 (isomer A). These results can be rationalized with two-dimensional (2D) orderings of p-TP molecules and different types of 2D shell closure at n = 7 and 14, the monomeric and multimeric anion core, respectively. Above n = 16, the new feature (isomer B) starts to appear at the higher binding side of isomer A, and it becomes dominant with n, while isomer A gradually disappears for larger sizes. In contrast to isomer A, the VDEs of isomer B continuously increase with the cluster size. This characteristic size evolution suggests that the transition to modified 2D aggregation forms from 2D ones occurs at around n = 20.

  6. Facile preparation of surface-exchangeable core@shell iron oxide@gold nanoparticles for magnetic solid-phase extraction: use of gold shell as the intermediate platform for versatile adsorbents with varying self-assembled monolayers.

    Science.gov (United States)

    Li, Yaping; Qi, Li; Shen, Ying; Ma, Huimin

    2014-02-06

    The core@shell Fe3O4@Au nanoparticles (NPs) functionalized with exchangeable self-assembled monolayers have been developed for mode switching magnetic solid-phase extraction (MSPE) using high performance liquid chromatography with ultraviolet detection. The adsorbents were synthesized by chemical coprecipitation to prepare magnetic cores followed by sonolysis to produce gold shells. Functionalization of Fe3O4@Au NPs surface was realized through self-assembly of commercially available low molecular weight thiol-containing ligands using gold shells as intermediate platform and the dynamic nature of Au-S chemistry allowed substituent of one thiol-containing ligand with another simply by thiol exchange process. The resultant adsorbents were characterized by transmission electronic microscopy, Fourier transform infrared spectroscopy, elemental analysis, contact angle measurement, and vibrating sample magnetometry. To evaluate the versatile performance of the developed MSPE adsorbents, they were applied for normal-phase SPE followed by reversed-phase SPE. A few kinds of diphenols and polycyclic aromatic hydrocarbons (PAHs) were employed as model analytes, respectively. The predominant parameters affecting extraction efficiency were investigated and optimized. Under the optimum experimental conditions, wide dynamic linear range (6.25-1600 μg L(-1) for diphenols and 1.56-100 μg L(-1) for PAHs) with good linearity (r(2)≥0.989) and low detection limits (0.34-16.67 μg L(-1) for diphenols and 0.26-0.52 μg L(-1) for PAHs) were achieved. The advantage of the developed method is that the Fe3O4@Au NPs could be reutilized for preconcentrating diverse target analytes in different SPE modes sequentially simply through treatment with desired thiol-containing ligands.

  7. Planetary Nebulae and their parent stellar populations. Tracing the mass assembly of M87 and Intracluster light in the Virgo cluster core

    CERN Document Server

    Arnaboldi, Magda; Gerhard, Ortwin

    2015-01-01

    The diffuse extended outer regions of galaxies are hard to study because they are faint, with typical surface brightness of 1% of the dark night sky. We can tackle this problem by using resolved star tracers which remain visible at large distances from the galaxy centres. This article describes the use of Planetary Nebulae as tracers and the calibration of their properties as indicators of the star formation history, mean age and metallicity of the parent stars in the Milky Way and Local Group galaxies . We then report on the results from a deep, extended, planetary nebulae survey in a 0.5 sqdeg region centred on the brightest cluster galaxy NGC 4486 (M87) in the Virgo cluster core, carried out with SuprimeCam@Subaru and FLAMES-GIRAFFE@VLT. Two PN populations are identified out to 150 kpc distance from the centre of M87. One population is associated with the M87 halo and the second one with the intracluster light in the Virgo cluster core. They have different line-of-sight velocity and spatial distributions, ...

  8. Novel strategy for the facile enrichment of isopentenyl pyrophosphate in rat plasma via Ti(4+) -immobilized polydopamine@Fe3 O4 core-shell microspheres.

    Science.gov (United States)

    Xu, Chen; Yu, Yingjia; Ling, Li; Sun, Xueni; Li, Yan; Duan, Gengli

    2017-05-01

    In this paper, a facile extraction strategy is reported for the analysis of isopentenyl pyrophosphate, a key isoprenoid, based on magnetic core-shell microspheres with Ti(4+) ion exterior walls coupled with liquid chromatography and tandem mass spectrometry. Because of their excellent hydrophilicity and biological compatibility, the polydopamine@Fe3 O4 -Ti(4+) microspheres display ideal isopentenyl pyrophosphate extraction efficiency. The technique includes three steps: sample loading, nonphosphate washing, and phosphate elution. Moreover, the microspheres can be regenerated by thorough washing with a specific solvent and can be reused multiple times. The liquid chromatography with tandem mass spectrometry separation was performed on a Welch Ultimate® XB-C18 column with a total chromatographic analysis time of 5 min; the analytical recovery was 98.52%. The proposed method was used to determine the isopentenyl pyrophosphate concentration in rat plasma samples collected from the Shanghai Chest Hospital. The results indicate the prospective value of the as-made microspheres for the sensitive and selective enrichment of phosphate compounds in complicated matrices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Experimental investigations of heat transfer and temperature fields in models simulating fuel assemblies used in the core of a nuclear reactor with a liquid heavy-metal coolant

    Science.gov (United States)

    Belyaev, I. A.; Genin, L. G.; Krylov, S. G.; Novikov, A. O.; Razuvanov, N. G.; Sviridov, V. G.

    2015-09-01

    The aim of this experimental investigation is to obtain information on the temperature fields and heat transfer coefficients during flow of liquid-metal coolant in models simulating an elementary cell in the core of a liquid heavy metal cooled fast-neutron reactor. Two design versions for spacing fuel rods in the reactor core were considered. In the first version, the fuel rods were spaced apart from one another using helical wire wound on the fuel rod external surface, and in the second version spacer grids were used for the same purpose. The experiments were carried out on the mercury loop available at the Moscow Power Engineering Institute National Research University's Chair of Engineering Thermal Physics. Two experimental sections simulating an elementary cell for each of the fuel rod spacing versions were fabricated. The temperature fields were investigated using a dedicated hinged probe that allows temperature to be measured at any point of the studied channel cross section. The heat-transfer coefficients were determined using the wall temperature values obtained at the moment when the probe thermocouple tail end touched the channel wall. Such method of determining the wall temperature makes it possible to alleviate errors that are unavoidable in case of measuring the wall temperature using thermocouples placed in slots milled in the wall. In carrying out the experiments, an automated system of scientific research was applied, which allows a large body of data to be obtained within a short period of time. The experimental investigations in the first test section were carried out at Re = 8700, and in the second one, at five values of Reynolds number. Information about temperature fields was obtained by statistically processing the array of sampled probe thermocouple indications at 300 points in the experimental channel cross section. Reach material has been obtained for verifying the codes used for calculating velocity and temperature fields in channels with

  10. A porous medium approach for the fluid structure interaction modelling of a water pressurized nuclear reactor core fuel assemblies: simulation and experimentation; Une approche milieu poreux pour la modeisation de l'interaction fluide-structure des assemblages combustibles dans un coeur de reacteur a eau pressurisee: simulation et experimentation

    Energy Technology Data Exchange (ETDEWEB)

    Ricciardi, G.

    2008-10-15

    The designing of a pressurized water reactor core subjected to seismic loading, is a major concern of the nuclear industry. We propose, in this PhD report, to establish the global behaviour equations of the core, in term of a porous medium. Local equations of fluid and structure are space averaged on a control volume, thus we define an equivalent fluid and an equivalent structure, of which unknowns are defined on the whole space. The non-linear fuel assemblies behaviour is modelled by a visco-elastic constitutive law. The fluid-structure coupling is accounted for by a body force, the expression of that force is based on empirical formula of fluid forces acting on a tube subject to an axial flow. The resulting equations are solved using a finite element method. A validation of the model, on three experimental device, is proposed. The first one presents two fuel assemblies subjected to axial flow. One of the two fuel assemblies is deviated from its position of equilibrium and released, while the other is at rest. The second one presents a six assemblies row, immersed in water, placed on a shaking table that can simulate seismic loading. Finally, the last one presents nine fuel assemblies network, arranged in a three by three, subject to an axial flow. The displacement of the central fuel assembly is imposed. The simulations are in agreement with the experiments, the model reproduces the influence of the flow of fluid on the dynamics and coupling of the fuel assemblies. (author)

  11. ELCOS: the PSI code system for LWR core analysis. Part II: user`s manual for the fuel assembly code BOXER

    Energy Technology Data Exchange (ETDEWEB)

    Paratte, J.M.; Grimm, P.; Hollard, J.M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-02-01

    ELCOS is a flexible code system for the stationary simulation of light water reactor cores. It consists of the four computer codes ETOBOX, BOXER, CORCOD and SILWER. The user`s manual of the second one is presented here. BOXER calculates the neutronics in cartesian geometry. The code can roughly be divided into four stages: - organisation: choice of the modules, file manipulations, reading and checking of input data, - fine group fluxes and condensation: one-dimensional calculation of fluxes and computation of the group constants of homogeneous materials and cells, - two-dimensional calculations: geometrically detailed simulation of the configuration in few energy groups, - burnup: evolution of the nuclide densities as a function of time. This manual shows all input commands which can be used while running the different modules of BOXER. (author) figs., tabs., refs.

  12. Planetary Nebulae and their parent stellar populations. Tracing the mass assembly of M87 and Intracluster light in the Virgo cluster core

    Science.gov (United States)

    Arnaboldi, Magda; Longobardi, Alessia; Gerhard, Ortwin

    2016-08-01

    The diffuse extended outer regions of galaxies are hard to study because they are faint, with typical surface brightness of 1% of the dark night sky. We can tackle this problem by using resolved star tracers which remain visible at large distances from the galaxy centers. This article describes the use of Planetary Nebulae as tracers and the calibration of their properties as indicators of the star formation history, mean age and metallicity of the parent stars in the Milky Way and Local Group galaxies. We then report on the results from a deep, extended, planetary nebulae survey in a 0.5 deg2 region centered on the brightest cluster galaxy NGC 4486 (M87) in the Virgo cluster core, carried out with SuprimeCam@Subaru and FLAMES-GIRAFFE@VLT. Two planetary nebulae populations are identified out to 150 kpc distance from the center of M87. One population is associated with the M87 halo and the second one with the intracluster light in the Virgo cluster core. They have different line-of-sight velocity and spatial distributions, as well as different planetary nebulae specific frequencies and luminosity functions. The intracluster planetary nebulae in the surveyed region correspond to a luminosity of four times the luminosity of the Large Magellanic Cloud. The M87 halo planetary nebulae trace an older, more metal-rich, parent stellar population. A substructure detected in the projected phase-space of the line-of-sight velocity vs. major axis distance for the M87 halo planetary nebulae provides evidence for the recent accretion event of a satellite galaxy with luminosity twice that of M33. The satellite stars were tidally stripped about 1 Gyr ago, and reached apocenter at a major axis distance of 60-90 kpc from the center of M87. The M87 halo is still growing significantly at the distances where the substructure is detected.

  13. J-aggregation, its impact on excited state dynamics and unique solvent effects on macroscopic assembly of a core-substituted naphthalenediimide

    KAUST Repository

    Kar, Haridas

    2015-03-12

    Herein we reveal a straightforward supramolecular design for the H-bonding driven J-aggregation of an amine-substituted cNDI in aliphatic hydrocarbons. Transient absorption spectroscopy reveals sub-ps intramolecular electron transfer in isolated NDI molecules in a THF solution followed by a fast recombination process, while a remarkable extension of the excited state lifetime by more than one order of magnitude occurred in methylcyclohexane likely owing to an increased charge-separation as a result of better delocalization of the charge-separated states in J-aggregates. We also describe unique solvent-effects on the macroscopic structure and morphology. While J-aggregation with similar photophysical characteristics was noticed in all the tested aliphatic hydrocarbons, the morphology strongly depends on the “structure” of the solvents. In linear hydrocarbons (n-hexane, n-octane, n-decane or n-dodecane), formation of an entangled fibrillar network leads to macroscopic gelation while in cyclic hydrocarbons (methylcyclohexane or cyclohexane) although having a similar polarity, the cNDI exhibits nanoscale spherical particles. These unprecedented solvent effects were rationalized by establishing structure-dependent specific interactions of the solvent molecules with the cNDI which may serve as a general guideline for solvent-induced morphology-control of structurally related self-assembled materials.

  14. The Structure of a BamA-BamD Fusion Illuminates the Architecture of the β-Barrel Assembly Machine Core.

    Science.gov (United States)

    Bergal, Hans Thor; Hopkins, Alex Hunt; Metzner, Sandra Ines; Sousa, Marcelo Carlos

    2016-02-01

    The β-barrel assembly machine (BAM) mediates folding and insertion of integral β-barrel outer membrane proteins (OMPs) in Gram-negative bacteria. Of the five BAM subunits, only BamA and BamD are essential for cell viability. Here we present the crystal structure of a fusion between BamA POTRA4-5 and BamD from Rhodothermus marinus. The POTRA5 domain binds BamD between its tetratricopeptide repeats 3 and 4. The interface structural elements are conserved in the Escherichia coli proteins, which allowed structure validation by mutagenesis and disulfide crosslinking in E. coli. Furthermore, the interface is consistent with previously reported mutations that impair BamA-BamD binding. The structure serves as a linchpin to generate a BAM model where POTRA domains and BamD form an elongated periplasmic ring adjacent to the membrane with a central cavity approximately 30 × 60 Å wide. We propose that nascent OMPs bind this periplasmic ring prior to insertion and folding by BAM.

  15. Miktoarm star copolymers from D-(-)-salicin core aggregated into dandelion-like structures as anticancer drug delivery systems: synthesis, self-assembly and drug release.

    Science.gov (United States)

    Mielańczyk, Anna; Odrobińska, Justyna; Grządka, Sebastian; Mielańczyk, Łukasz; Neugebauer, Dorota

    2016-12-30

    The β-glucoside-based heterofunctional initiator was used in the synthesis of well-defined eight-armed miktopolymers by sequential ring opening polymerization (ROP) of ε-caprolactone (CL) and atom transfer radical (co)polymerization (ATRP) of methyl methacrylate (MMA) and/or tert-butyl methacrylate (tBMA). Consequently, methacrylic acid (MAA) repeating units were introduced via selective cleavage of pendant tert-butyl protecting groups. Both the amphiphilic copolymers and miktoarm copolymers were self-assembled at 37°C and pH 7.4. The aggregates of miktoarm polymers were larger than that formed by polymethacrylate homoarm stars (≥250nm vs ≤200nm). The critical aggregation concentrations (CAC) of (mikto)stars were relatively low (0.006-0.411mg/mL) and decreased with the increase in MAA fraction content. Both MAA-based mikto- and homoarmed (co)polymers with shorter arms exhibited lower doxorubicin (DOX) loading capacity, whereas camptothecin (CPT) was encapsulated preferably by miktostars. The kinetic profiles of drug release showed that the rate of release was higher at acidic environment (pH 5.0) than in neutral pH. In the most cases the studied miktopolymer systems demonstrated the well-controlled delivery of the model anticancer drugs, which can be adjusted by structural parameters of polymeric carriers.

  16. Method of making hermetic seals for hermetic terminal assemblies

    Science.gov (United States)

    Hsu, John S.; Marlino, Laura D.; Ayers, Curtis W.

    2010-04-13

    This invention teaches methods of making a hermetic terminal assembly comprising the steps of: inserting temporary stops, shims and jigs on the bottom face of a terminal assembly thereby blocking assembly core open passageways; mounting the terminal assembly inside a vacuum chamber using a temporary assembly perimeter seal and flange or threaded assembly interfaces; mixing a seal admixture and hardener in a mixer conveyor to form a polymer seal material; conveying the polymer seal material into a polymer reservoir; feeding the polymer seal material from the reservoir through a polymer outlet valve and at least one polymer outlet tube into the terminal assembly core thereby filling interstitial spaces in the core adjacent to service conduits, temporary stop, and the terminal assembly casing; drying the polymer seal material at room temperature thereby hermetically sealing the core of the terminal assembly; removing the terminal assembly from the vacuum chamber, and; removing the temporary stops, shims.

  17. Assessment of heavy metal contamination in core sediment samples in Gulf of Izmir, Aegean Sea, Turkey (by inductively coupled plasma-optical emission spectrometry (ICP-OES))

    Science.gov (United States)

    Ünal Yumun, Zeki; Kam, Erol; Kurt, Dilek

    2017-04-01

    Heavy metal and radionuclide analysis studies are crucial in explaining biotic and abiotic interactions in ecosystems. This type of analysis is highly needed in environments such as coastal areas, gulfs or lakes where human activities are generally concentrated. Sediments are one of the best biological indicators for the environment since the pollution accumulates in the sediments by descent to the sea floor. In this study, sediments were collected from the Gulf of Izmir (Eastern Aegean Sea, Turkey) considering the accumulated points of domestic and industrial wastes to make an anthropogenic pollution analysis. The core sediments had different depths of 0.00-30.00 m at four different locations where Karsiyaka, Bayrakli, Incialti and Cesmealti in the Gulf of Izmir. The purpose of the study was determining Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn concentrations in the drilling samples to assess their levels and spatial distribution in crucial areas of the Aegean Sea by inductively coupled plasma-optical emission spectrometry (ICP-OES) with microwave digestion techniques. The heavy metal concentrations found in sediments varied for Cd:

  18. Core-Shell and Segmented Polymer-Metal Composite Nanostructures

    Science.gov (United States)

    Lahav, Michal; Weiss, Emily; Xu, Qiaobing; Whitesides, George M.

    2008-01-01

    Composite nanostructures (~200 nm wide and several μm long) of metal and polyaniline (PANI) in two new variations of core-shell (PANI-Au) and segmented (Au-PANI and Ni-Au-PANI) architectures were fabricated electrochemically within anodized aluminum oxide (AAO) membranes. Control over the structure of these composites (including the length of the gold shells in the core-shell structures) was accomplished by adjusting the time and rate of electrodeposition, and the pH of the solution from which the materials were grown. Exposure of the core-shell structures to oxygen plasma removed the PANI and yielded aligned gold nanotubes. In the segmented structures, a self-assembled monolayer (SAM) of thioaniline nucleated the growth of PANI on top of metal nanorods, and acted as an adhesion layer between the metal and PANI components. PMID:16968046

  19. A crystal structure of the catalytic core domain of an avian sarcoma and leukemia virus integrase suggests an alternate dimeric assembly.

    Science.gov (United States)

    Ballandras, Allison; Moreau, Karen; Robert, Xavier; Confort, Marie-Pierre; Merceron, Romain; Haser, Richard; Ronfort, Corinne; Gouet, Patrice

    2011-01-01

    Integrase (IN) is an important therapeutic target in the search for anti-Human Immunodeficiency Virus (HIV) inhibitors. This enzyme is composed of three domains and is hard to crystallize in its full form. First structural results on IN were obtained on the catalytic core domain (CCD) of the avian Rous and Sarcoma Virus strain Schmidt-Ruppin A (RSV-A) and on the CCD of HIV-1 IN. A ribonuclease-H like motif was revealed as well as a dimeric interface stabilized by two pairs of α-helices (α1/α5, α5/α1). These structural features have been validated in other structures of IN CCDs. We have determined the crystal structure of the Rous-associated virus type-1 (RAV-1) IN CCD to 1.8 Å resolution. RAV-1 IN shows a standard activity for integration and its CCD differs in sequence from that of RSV-A by a single accessible residue in position 182 (substitution A182T). Surprisingly, the CCD of RAV-1 IN associates itself with an unexpected dimeric interface characterized by three pairs of α-helices (α3/α5, α1/α1, α5/α3). A182 is not involved in this novel interface, which results from a rigid body rearrangement of the protein at its α1, α3, α5 surface. A new basic groove that is suitable for single-stranded nucleic acid binding is observed at the surface of the dimer. We have subsequently determined the structure of the mutant A182T of RAV-1 IN CCD and obtained a RSV-A IN CCD-like structure with two pairs of buried α-helices at the interface. Our results suggest that the CCD of avian INs can dimerize in more than one state. Such flexibility can further explain the multifunctionality of retroviral INs, which beside integration of dsDNA are implicated in different steps of the retroviral cycle in presence of viral ssRNA.

  20. Arrested relaxation in an isolated molecular ultracold plasma

    Science.gov (United States)

    Haenel, R.; Schulz-Weiling, M.; Sous, J.; Sadeghi, H.; Aghigh, M.; Melo, L.; Keller, J. S.; Grant, E. R.

    2017-08-01

    Spontaneous avalanche to plasma splits the core of an ellipsoidal Rydberg gas of nitric oxide. Ambipolar expansion first quenches the electron temperature of this core plasma. Then, long-range, resonant charge transfer from ballistic ions to frozen Rydberg molecules in the wings of the ellipsoid quenches the ion-Rydberg-molecule relative velocity distribution. This sequence of steps gives rise to a remarkable mechanics of self-assembly, in which the kinetic energy of initially formed hot electrons and ions drives an observed separation of plasma volumes. These dynamics adiabatically sequester energy in a reservoir of mass transport, starting a process that anneals separating volumes to form an apparent glass of strongly coupled ions and electrons. Short-time electron spectroscopy provides experimental evidence for complete ionization. The long lifetime of this system, particularly its stability with respect to recombination and neutral dissociation, suggests that this transformation affords a robust state of arrested relaxation, far from thermal equilibrium.

  1. Symmetry-Driven Strategy for the Assembly of the Core Tetracycle of (+)-Ryanodine: Synthetic Utility of a Cobalt-Catalyzed Olefin Oxidation and α-Alkoxy Bridgehead Radical Reaction.

    Science.gov (United States)

    Nagatomo, Masanori; Hagiwara, Koji; Masuda, Kengo; Koshimizu, Masaki; Kawamata, Takahiro; Matsui, Yuki; Urabe, Daisuke; Inoue, Masayuki

    2016-01-01

    Ryanodine (1) is a potent modulator of intracellular calcium release channels, designated as ryanodine receptors. The exceptionally complex molecular architecture of 1 comprises a highly oxygenated pentacyclic system with eleven contiguous stereogenic centers, which makes it a formidable target for organic synthesis. We identified the embedded C2 -symmetric tricyclic substructure within 1. This specific recognition permitted us to design a concise synthetic route to enantiopure tricycle 9 by utilizing a series of pairwise functionalizations. The four tetrasubstituted carbon centers of 9 were effectively constructed by three key reactions, a dearomatizing Diels-Alder reaction, the kinetic resolution of the obtained racemic 14 through asymmetric methanolysis, and the transannular aldol reaction of the eight-membered diketone 10. A new combination of cobalt-catalyzed hydroperoxidation and NfF-promoted elimination enabled conversion of the hindered olefin of 9 into the corresponding ketone, thus realizing the desymmetrization. Finally, the tetrasubstituted carbon was stereospecifically installed by utilizing the α-alkoxy bridgehead radical to deliver the core tetracycle 7 with the six contiguous tetrasubstituted carbon centers. Consequently, the present work not only accomplishes efficient assembly of four out of the five fused rings of 1, but also develops two new powerful methodologies: two-step ketone formation and bridgehead radical reaction.

  2. Mitochondria-driven assembly of a cortical anchor for mitochondria and dynein.

    Science.gov (United States)

    Kraft, Lauren M; Lackner, Laura L

    2017-10-02

    Interorganelle contacts facilitate communication between organelles and impact fundamental cellular functions. In this study, we examine the assembly of the MECA (mitochondria-endoplasmic reticulum [ER]-cortex anchor), which tethers mitochondria to the ER and plasma membrane. We find that the assembly of Num1, the core component of MECA, requires mitochondria. Once assembled, Num1 clusters persistently anchor mitochondria to the cell cortex. Num1 clusters also function to anchor dynein to the plasma membrane, where dynein captures and walks along astral microtubules to help orient the mitotic spindle. We find that dynein is anchored by Num1 clusters that have been assembled by mitochondria. When mitochondrial inheritance is inhibited, Num1 clusters are not assembled in the bud, and defects in dynein-mediated spindle positioning are observed. The mitochondria-dependent assembly of a dual-function cortical anchor provides a mechanism to integrate the positioning and inheritance of the two essential organelles and expands the function of organelle contact sites. © 2017 Kraft and Lackner.

  3. Fuel assembly reconstitution

    Energy Technology Data Exchange (ETDEWEB)

    Morgado, Mario M.; Oliveira, Monica G.N.; Ferreira Junior, Decio B.M.; Santos, Barbara O. dos; Santos, Jorge E. dos, E-mail: mongeor@eletronuclear.gov.b [ELETROBRAS Termonuclear S.A. - ELETRONUCLEAR, Angra dos Reis, RJ (Brazil)

    2009-07-01

    Fuel failures have been happened in Nuclear Power Plants worldwide, without lost of integrity and safety, mainly for the public, environment and power plants workers. The most common causes of these events are corrosion (CRUD), fretting and pellet cladding interaction. These failures are identified by increasing the activity of fission products, verified by chemical analyses of reactor coolant. Through these analyses, during the fourth operation cycle of Angra 2 Nuclear Power Plant, was possible to observe fuel failure indication. This indication was confirmed in the end of the cycle during the unloading of reactor core through leakage tests of fuel assembly, using the equipment called 'In Mast Sipping' and 'Box Sipping'. After confirmed, the fuel assembly reconstitution was scheduled, and happened in April, 2007, where was identified the cause and the fuel rod failure, which was substitute by dummy rods (zircaloy). The cause was fretting by 'debris'. The actions to avoid and prevent fuel assemblies failures are important. The goals of this work are to describe the methodology of fuel assembly reconstitution using the FARE (Fuel Assembly Reconstitution Equipment) system, to describe the results of this task in economic and security factors of the company and show how the fuel assembly failures are identified during operation and during the outage. (author)

  4. Oxygen plasma etching-induced crystalline lattice transformation of colloidal photonic crystals.

    Science.gov (United States)

    Ding, Tao; Wang, Fei; Song, Kai; Yang, Guoqiang; Tung, Chen-Ho

    2010-12-15

    This communication describes the transformation of a colloidal crystalline lattice that was realized via oxygen plasma etching of colloidal crystals made of SiO2@PMMA core-shell microspheres. The plasma etching of the colloidal crystals proceeded nonuniformly from the top to the bottom of the colloidal crystals. The PMMA shell was etched away by the oxygen plasma in a layer-by-layer manner, and the silica core was drawn into the pit formed by the neighboring spheres in the layer below. Consequently, the crystalline lattice was transformed while the order was maintained. Scanning electron microscopy images and reflection spectra further confirmed the change in the crystalline structures. Colloidal crystals with sc and bcc lattices can be fabricated if the ratio of the polymer shell thickness to the silica core diameter is equal to certain values. More importantly, this approach may be applicable to the fabrication of various assembly structures with different inorganic particles.

  5. Crystal Structure of the Human Cytomegalovirus pUL50-pUL53 Core Nuclear Egress Complex Provides Insight into a Unique Assembly Scaffold for Virus-Host Protein Interactions.

    Science.gov (United States)

    Walzer, Sascha A; Egerer-Sieber, Claudia; Sticht, Heinrich; Sevvana, Madhumati; Hohl, Katharina; Milbradt, Jens; Muller, Yves A; Marschall, Manfred

    2015-11-13

    Nuclear replication of cytomegalovirus relies on elaborate mechanisms of nucleocytoplasmic egress of viral particles. Thus, the role of two essential and conserved viral nuclear egress proteins, pUL50 and pUL53, is pivotal. pUL50 and pUL53 heterodimerize and form a core nuclear egress complex (NEC), which is anchored to the inner nuclear membrane and provides a scaffold for the assembly of a multimeric viral-cellular NEC. Here, we report the crystal structure of the pUL50-pUL53 heterodimer (amino acids 1-175 and 50-292, respectively) at 2.44 Å resolution. Both proteins adopt a globular fold with mixed α and β secondary structure elements. pUL53-specific features include a zinc-binding site and a hook-like N-terminal extension, the latter representing a hallmark element of the pUL50-pUL53 interaction. The hook-like extension (amino acids 59-87) embraces pUL50 and contributes 1510 Å(2) to the total interface area (1880 Å(2)). The pUL50 structure overall resembles the recently published NMR structure of the murine cytomegalovirus homolog pM50 but reveals a considerable repositioning of the very C-terminal α-helix of pUL50 upon pUL53 binding. pUL53 shows structural resemblance with the GHKL domain of bacterial sensory histidine kinases. A close examination of the crystal structure indicates partial assembly of pUL50-pUL53 heterodimers to hexameric ring-like structures possibly providing additional scaffolding opportunities for NEC. In combination, the structural information on pUL50-pUL53 considerably improves our understanding of the mechanism of HCMV nuclear egress. It may also accelerate the validation of the NEC as a unique target for developing a novel type of antiviral drug and improved options of broad-spectrum antiherpesviral therapy.

  6. Proteomics Core

    Data.gov (United States)

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in a...

  7. Proteomics Core

    Data.gov (United States)

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in...

  8. Ni-catalysed carbon nanotubes and nanofibers assemblies grown on TiN/Si(1 0 0) substrates using hot-filaments combined with d.c. plasma CVD

    Science.gov (United States)

    Fleaca, Claudiu Teodor; Le Normand, François

    2014-02-01

    Different carbon nanotubes or nanofibers (CNTs or CNFs) assemblies were obtained using Ni catalyst deposited by Pulsed Laser Deposition (PLD) on TiN/Si(1 0 0) substrate from a H2/C2H2 mixture using plasma emerging from triode configured electrodes with two pairs of intercalated incandescent filaments at 1 kPa and 700 °C. In the presence of a relative intense plasma (54 W power), a dense CNT carpet was grown. The TEM images revealed the presence of elongated yet contorted 10-15 nm diameter CNTs with encapsulated Ni particles at their tips. Using a low plasma power (8 W) in similar conditions and from the same catalyst, a different morphology resulted: few self-sustained long fibrils (diameter around 1 μm) which are curved under the action of their own weight containing compacted CNTs/CNFs and (only in the confined zones near the lateral edges) 50-200 nm thick filaments presenting buds-like structures and Y-shape junctions.

  9. Improvement of magnetic hysteresis loss, corrosion resistance and compressive strength through spark plasma sintering magnetocaloric LaFe11.65Si1.35/Cu core-shell powders

    Directory of Open Access Journals (Sweden)

    Caiyin You

    2016-05-01

    Full Text Available LaFe11.65Si1.35/Cu core-shell powders were achieved by self-designed magnetron sputtering system, which presents a better solidification during spark plasma sintering in comparison to the naked LaFe11.65Si1.35 powders. Much higher compressive strength, lower corrosion current density and magnetic hysteresis losses are achieved for the sintered sample of LaFe11.65Si1.35/Cu core-shell powders without significant decrease of the magnetic entropy change. The compressive strength, corrosion current density and maximum magnetic hysteresis losses are 105.6 MPa/16.8 MPa, 1.08 × 10−3A/cm2/3.03 × 10−3 A/cm2 and 1.33 J/kg/2.71 J/kg, respectively for the sintered samples of core-shell structured/naked powders. The technique of fabricating the core-shell structured powders demonstrated here is also applicable for other types of functional powders.

  10. Sequence assembly

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria

    2009-01-01

    Despite the rapidly increasing number of sequenced and re-sequenced genomes, many issues regarding the computational assembly of large-scale sequencing data have remain unresolved. Computational assembly is crucial in large genome projects as well for the evolving high-throughput technologies...

  11. The performances of silicon solar cell with core-shell p-n junctions of micro-nano pillars fabricated by cesium chloride self-assembly and dry etching

    Science.gov (United States)

    Liu, Jing; Zhang, Xinshuai; Dong, Gangqiang; Liao, Yuanxun; Wang, Bo; Zhang, Tianchong; Yi, Futing

    2014-03-01

    Silicon micro-nano pillars are cost-efficiently integrated using twice cesium chloride (CsCl) islands lithography technique and dry etching for solar cell applications. The micro PMMA islands are fabricated by inductively coupled plasma (ICP) dry etching with micro CsCl islands as masks, and the nano CsCl islands with nano sizes then are made on the surface of micro PMMA islands and silicon. By ICP dry etching with the mask of micro PMMA islands and nano CsCl islands, the micro-nano silicon pillars are made and certain height micro pillars are randomly positioned between dense arrays of nano pillars with different morphologies by controlling etching conditions. With 300 nm depth p-n junction detected by secondary-ion mass spectrometry (SIMS), the micro pillars of the diameter about 1 μm form the core-shell p-n junction to maximize utility of p-n junction interface and enable efficient free carrier collection, and the nano tapered pillars of 150 nm diameter are used to decrease reflection by a graded-refractive-index. Compared to single micro or nano pillar arrayed cells, the co-integrated solar cell with micro and nano pillars demonstrates improved photovoltaic characteristic that is a photovoltaic conversion efficiency (PCE) of 15.35 % with a short circuit current density ( J sc) of 38.40 mA/cm2 and an open circuit voltage ( V oc) of 555.7 mV, which benefits from the advantages of micro-nano pillar structures and can be further improved upon process optimization.

  12. 基于GDT的聚变裂变混合堆堆芯参数初步设计研究%Preliminary design of core plasma parameters for the fusion-fission hybrid reactor based on GDT

    Institute of Scientific and Technical Information of China (English)

    陈德鸿; 杜红飞; 蒋洁琼; 汪晖; 王福琼; 陈一平; 吴宜灿; FDS团队

    2012-01-01

    Based on the recent experiment progress of Gas Dynamic Trap (GDT), a core plasma physics conceptual design for driving fission blanket was proposed The 0-D physical model was built and the core plasma parameters with 50 MW fusion power were preliminarily designed The reliability of the physical model and design was demonstrated by comparison between the calculation and the experiment results.%基于Gas Dynamic Trap(GDT)装置的实验进展,提出了用于驱动聚变裂变混合堆包层的聚变堆芯参数设计.基于零维堆芯物理模型,计算分析给出了一套聚变功率为50 MW的初步堆芯参数方案.利用GDT装置的实验结果对该物理模型进行计算对比校验,显示该物理模型和设计参数的可靠性.

  13. Study on Effect of MOX Fuel Assembly Loaded in Current M310 Reactor Core on Nuclear Design%MOX 燃料组件装入现役 M310堆芯对堆芯核设计的影响研究

    Institute of Scientific and Technical Information of China (English)

    刘晓黎; 宫宇

    2015-01-01

    国际上的 MOX 燃料技术目前已较为成熟,且已有在压水堆中运行的工程经验。本文对 MOX 燃料组件的中子学性能进行了分析,对其在我国现役 M310堆芯应用的可行性进行了研究,得到了 M310堆芯由全部使用 UO2燃料组件向使用30%的 MOX 燃料组件过渡的堆芯燃料管理方案,并对使用MOX 燃料组件的堆芯的部分中子学参数进行了初步分析。结果表明:使用30%的 MOX 燃料组件的堆芯可达到与全 UO2堆芯相当的循环长度;堆芯反应性控制能力可满足要求;慢化剂温度系数、Doppler温度系数、Doppler 功率系数、氙和钐的动态特性均趋向使堆芯运行更加安全和稳定。本文的研究结果可为 MOX 燃料在 M310堆芯中应用的进一步研究提供参考。%The MOX fuel technology has been developed and applied in PWR all over the world .In this paper ,the neutronic performance of the MOX fuel assembly was studied , and fuel management scheme of M310 reactor core from all UO2 fuel assemblies to 30%MOX fuel assemblies was given .The results show that the core loaded 30% MOX fuel assemblies can reach the same lifetime as the all UO2 core ,the ability of the control system can meet the requirement of reactivity control ,and the Doppler temperature and power coefficients ,moderator temperature coefficient and the evolutions of Xe and Sm all benefit for the core operation to be more stable .The results of this study prove that the MOX fuel assembly can be used in the M310 reactor core .

  14. Multiplexed next-generation sequencing and de novo assembly to obtain near full-length HIV-1 genome from plasma virus.

    Science.gov (United States)

    Aralaguppe, Shambhu G; Siddik, Abu Bakar; Manickam, Ashokkumar; Ambikan, Anoop T; Kumar, Milner M; Fernandes, Sunjay Jude; Amogne, Wondwossen; Bangaruswamy, Dhinoth K; Hanna, Luke Elizabeth; Sonnerborg, Anders; Neogi, Ujjwal

    2016-10-01

    Analysing the HIV-1 near full-length genome (HIV-NFLG) facilitates new understanding into the diversity of virus population dynamics at individual or population level. In this study we developed a simple but high-throughput next generation sequencing (NGS) protocol for HIV-NFLG using clinical specimens and validated the method against an external quality control (EQC) panel. Clinical specimens (n=105) were obtained from three cohorts from two highly conserved HIV-1C epidemics (India and Ethiopia) and one diverse epidemic (Sweden). Additionally an EQC panel (n=10) was used to validate the protocol. HIV-NFLG was performed amplifying the HIV-genome (Gag-to-nef) in two fragments. NGS was performed using the Illumina HiSeq2500 after multiplexing 24 samples, followed by de novo assembly in Iterative Virus Assembler or VICUNA. Subtyping was carried out using several bioinformatics tools. Amplification of HIV-NFLG has 90% (95/105) success-rate in clinical specimens. NGS was successful in all clinical specimens (n=45) and EQA samples (n=10) attempted. The mean error for mutations for the EQC panel viruses were <1%. Subtyping identified two as A1C recombinant. Our results demonstrate the feasibility of a simple NGS-based HIV-NFLG that can potentially be used in the molecular surveillance for effective identification of subtypes and transmission clusters for operational public health intervention.

  15. An enzymatic deglycosylation scheme enabling identification of core fucosylated N-glycans and O-glycosylation site mapping of human plasma proteins

    DEFF Research Database (Denmark)

    Hägglund, Per; Matthiesen, R.; Elortza, F.;

    2007-01-01

    between the two N-acetylglucosamine (GlcNAc) residues in the conserved N-glycan core structure, leaving single GlcNAc residues with putative fucosyl side chains attached to the peptide. To enable digestion of complex and hybrid type N-glycans, a number of exoglycosidases (β-galactosidase, neuraminidase...

  16. Dense-cored vesicles, smooth endoplasmic reticulum, and mitochondria are closely associated with non-specialized parts of plasma membrane of nerve terminals: implications for exocytosis and calcium buffering by intraterminal organelles.

    Science.gov (United States)

    Lysakowski, A; Figueras, H; Price, S D; Peng, Y Y

    1999-01-18

    To determine whether there are anatomical correlates for intraterminal Ca2+ stores to regulate exocytosis of dense-cored vesicles (DCVs) and whether these stores can modulate exocytosis of synaptic vesicles, we studied the spatial distributions of DCVs, smooth endoplasmic reticulum (SER), and mitochondria in 19 serially reconstructed nerve terminals in bullfrog sympathetic ganglia. On average, each bouton had three active zones, 214 DCVs, 26 SER fragments (SERFs), and eight mitochondria. DCVs, SERFs and mitochondria were located, on average, 690, 624, and 526 nm, respectively, away from active zones. Virtually no DCVs were within "docking" (i.e., similar to those for exocytosis of synaptic vesicles. Because there were virtually no SERFs or mitochondria within 50 nm of any active zone, Ca2+ modulation by these organelles is unlikely to affect ACh release evoked by a single action potential. In contrast, 30% of DCVs and 40% of SERFs were located within 50 nm of the nonspecialized regions of the plasma membrane. Because each bouton had at least one SERF within 50 nm of the plasma membrane and most of these SERFs had DCVs, but not mitochondria, near them, it is possible for Ca2+ release from the SER to provide the Ca2+ necessary for DCV exocytosis. The fact that 60% of the mitochondria had some part within 50 nm of the plasma membrane means that it is possible for mitochondrial Ca2+ buffering to affect DCV exocytosis.

  17. Ice cores

    DEFF Research Database (Denmark)

    Svensson, Anders

    2014-01-01

    Ice cores from Antarctica, from Greenland, and from a number of smaller glaciers around the world yield a wealth of information on past climates and environments. Ice cores offer unique records on past temperatures, atmospheric composition (including greenhouse gases), volcanism, solar activity......, dustiness, and biomass burning, among others. In Antarctica, ice cores extend back more than 800,000 years before present (Jouzel et al. 2007), whereas. Greenland ice cores cover the last 130,000 years...

  18. Ice cores

    DEFF Research Database (Denmark)

    Svensson, Anders

    2014-01-01

    Ice cores from Antarctica, from Greenland, and from a number of smaller glaciers around the world yield a wealth of information on past climates and environments. Ice cores offer unique records on past temperatures, atmospheric composition (including greenhouse gases), volcanism, solar activity......, dustiness, and biomass burning, among others. In Antarctica, ice cores extend back more than 800,000 years before present (Jouzel et al. 2007), whereas. Greenland ice cores cover the last 130,000 years...

  19. Lateral Stiffness Analysis of Fuel Assembly as Contact Condition for PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K. H.; Lee, C. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    To evaluate the fuel assembly bowing in the core, the lateral stiffness analysis is needed. In the fuel assembly, there are two load pads. One is the top load pad (TLP) and the other is above the core load pad (ACLP). These load pads supply the impact surface among the fuel assemblies. In this paper, the lateral stiffness analysis of the fuel assembly as the core contact condition will be executed using the finite element method. The lateral stiffness of a fuel assembly is established by the FE method. These analysis results will be utilized in a fuel assembly bowing analysis in the core.

  20. Plasma transport in the Scrape-off-Layer of magnetically confined plasma and the plasma exhaust

    DEFF Research Database (Denmark)

    Rasmussen, Jens Juul; Naulin, Volker; Nielsen, Anders Henry

    An overview of the plasma dynamics in the Scrape-off-Layer (SOL) of magnetically confined plasma is presented. The SOL is the exhaust channel of the warm plasma from the core, and the understanding of the SOL plasma dynamics is one of the key issues in contemporary fusion research. It is essential...

  1. Tablet—next generation sequence assembly visualization

    OpenAIRE

    Milne, Iain; Bayer, Micha; Cardle, Linda; Shaw, Paul; Stephen, Gordon; Wright, Frank; Marshall, David

    2009-01-01

    Summary: Tablet is a lightweight, high-performance graphical viewer for next-generation sequence assemblies and alignments. Supporting a range of input assembly formats, Tablet provides high-quality visualizations showing data in packed or stacked views, allowing instant access and navigation to any region of interest, and whole contig overviews and data summaries. Tablet is both multi-core aware and memory efficient, allowing it to handle assemblies containing millions of reads, even on a 32...

  2. Overview of the HUPO Plasma Proteome Project: Results from the pilot phase with 35 collaborating laboratories and multiple analytical groups, generating a core dataset of 3020 proteins and a publicly-available database

    Energy Technology Data Exchange (ETDEWEB)

    Omenn, Gilbert; States, David J.; Adamski, Marcin; Blackwell, Thomas W.; Menon, Rajasree; Hermjakob, Henning; Apweiler, Rolf; Haab, Brian B.; Simpson, Richard; Eddes, James; Kapp, Eugene; Moritz, Rod; Chan, Daniel W.; Rai, Alex J.; Admon, Arie; Aebersold, Ruedi; Eng, Jimmy K.; Hancock, William S.; Hefta, Stanley A.; Meyer, Helmut; Paik, Young-Ki; Yoo, Jong-Shin; Ping, Peipei; Pounds, Joel G.; Adkins, Joshua N.; Qian, Xiaohong; Wang, Rong; Wasinger, Valerie; Wu, Chi Yue; Zhao, Xiaohang; Zeng, Rong; Archakov, Alexander; Tsugita, Akira; Beer, Ilan; Pandey, Akhilesh; Pisano, Michael; Andrews, Philip; Tammen, Harald; Speicher, David W.; Hanash, Samir M.

    2005-08-13

    HUPO initiated the Plasma Proteome Project (PPP) in 2002. Its pilot phase has (1) evaluated advantages and limitations of many depletion, fractionation, and MS technology platforms; (2) compared PPP reference specimens of human serum and EDTA, heparin, and citrate-anticoagulated plasma; and (3) created a publicly-available knowledge base (www.bioinformatics. med.umich.edu/hupo/ppp; www.ebi.ac.uk/pride). Thirty-five participating laboratories in 13 countries submitted datasets. Working groups addressed (a) specimen stability and protein concentrations; (b) protein identifications from 18 MS/MS datasets; (c) independent analyses from raw MS-MS spectra; (d) search engine performance, subproteome analyses, and biological insights; (e) antibody arrays; and (f) direct MS/SELDI analyses. MS-MS datasets had 15 710 different International Protein Index (IPI) protein IDs; our integration algorithm applied to multiple matches of peptide sequences yielded 9504 IPI proteins identified with one or more peptides and 3020 proteins identified with two or more peptides (the Core Dataset). These proteins have been characterized with Gene Ontology, InterPro, Novartis Atlas, OMIM, and immunoassay based concentration determinations. The database permits examination of many other subsets, such as 1274 proteins identified with three or more peptides. Reverse protein to DNA matching identified proteins for 118 previously unidentified ORFs. We recommend use of plasma instead of serum, with EDTA (or citrate) for anticoagulation. To improve resolution, sensitivity and reproducibility of peptide identifications and protein matches, we recommend combinations of depletion, fractionation, and MS/MS technologies, with explicit criteria for evaluation of spectra, use of search algorithms, and integration of homologous protein matches. This Special Issue of PROTEOMICS presents papers integral to the collaborative analysis plus many reports of supplementary work on various aspects of the PPP workplan

  3. Nuclear reactor composite fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, Donn M. (Richland, WA); Marr, Duane R. (West Richland, WA); Cappiello, Michael W. (Richland, WA); Omberg, Ronald P. (Richland, WA)

    1980-01-01

    A core and composite fuel assembly for a liquid-cooled breeder nuclear reactor including a plurality of elongated coextending driver and breeder fuel elements arranged to form a generally polygonal bundle within a thin-walled duct. The breeder elements are larger in cross section than the driver elements, and each breeder element is laterally bounded by a number of the driver elements. Each driver element further includes structure for spacing the driver elements from adjacent fuel elements and, where adjacent, the thin-walled duct. A core made up of the fuel elements can advantageously include fissile fuel of only one enrichment, while varying the effective enrichment of any given assembly or core region, merely by varying the relative number and size of the driver and breeder elements.

  4. Conceptual study of advanced PWR core design

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Chang, Moon Hee; Kim, Keung Ku; Joo, Hyung Kuk; Kim, Young Il; Noh, Jae Man; Hwang, Dae Hyun; Kim, Taek Kyum; Yoo, Yon Jong

    1997-09-01

    The purpose of this project is for developing and verifying the core design concepts with enhanced safety and economy, and associated methodologies for core analyses. From the study of the sate-of-art of foreign advanced reactor cores, we developed core concepts such as soluble boron free, high convertible and enhanced safety core loaded semi-tight lattice hexagonal fuel assemblies. To analyze this hexagonal core, we have developed and verified some neutronic and T/H analysis methodologies. HELIOS code was adopted as the assembly code and HEXFEM code was developed for hexagonal core analysis. Based on experimental data in hexagonal lattices and the COBRA-IV-I code, we developed a thermal-hydraulic analysis code for hexagonal lattices. Using the core analysis code systems developed in this project, we designed a 600 MWe core and studied the feasibility of the core concepts. Two additional scopes were performed in this project : study on the operational strategies of soluble boron free core and conceptual design of large scale passive core. By using the axial BP zoning concept and suitable design of control rods, this project showed that it was possible to design a soluble boron free core in 600 MWe PWR. The results of large scale core design showed that passive concepts and daily load follow operation could be practiced. (author). 15 refs., 52 tabs., 101 figs.

  5. Self-assembled flower-like nanostructures of InN and GaN grown by plasma-assisted molecular beam epitaxy

    Indian Academy of Sciences (India)

    Mahesh Kumar; T N Bhat; M K Rajpalke; B Roul; P Misra; L M Kukreja; Neeraj Sinha; A T Kalghatgi; S B Krupanidhi

    2010-06-01

    Nanosized hexagonal InN flower-like structures were fabricated by droplet epitaxy on GaN/Si(111) and GaN flower-like nanostructure fabricated directly on Si(111) substrate using radio frequency plasma-assisted molecular beam epitaxy. Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study the crystallinity and morphology of the nanostructures. Moreover, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) were used to investigate the chemical compositions and optical properties of nano-flowers, respectively. Activation energy of free exciton transitions in GaN nano-flowers was derived to be ∼ 28.5 meV from the temperature dependent PL studies. The formation process of nanoflowers is investigated and a qualitative mechanism is proposed.

  6. Single-particle inductively coupled plasma mass spectroscopy analysis of size and number concentration in mixtures of monometallic and bimetallic (core-shell) nanoparticles.

    Science.gov (United States)

    Merrifield, Ruth C; Stephan, Chady; Lead, Jamie R

    2017-01-01

    It is challenging to separate and measure the physical and chemical properties of monometallic and bimetallic engineered nanoparticles (NPs), especially when mixtures are similar in size and at low concentration. We report that single particle inductively coupled mass spectroscopy (SP-ICP-MS), alongside field flow fractionation (FFF), has allowed for the accurate measurement of size and particle number concentrations of mixed metallic nanoparticles (NPs) containing monometallic NPs of gold (Au) and silver (Ag) and a bimetallic core-shell structured NP (Au@Ag) of equivalent size. Two sets of these NPs were measured. The first contained only 60nm particles, where the Au@Ag NP had a 30nm core and 15nm shell to make a total diameter of 60nm. The second contained only 80nm particles (Au@Ag NP core particle of 50nm with a 15nm shell). FFF separation was used here as a sizing technique rather than a separation technique. It was used to confirm that suspensions containing either individual or mixtures of the Au 60nm, Ag 60nm and AuAg 60nm suspensions eluted together and were of the same size. Similarly, FFF was used to show that suspensions containing individual or mixtures of the equivalent 80nm, eluted together and were of the same size. Although the 60nm and 80nm suspensions did not elute at the same time they were not run together. SP-ICP-MS is then used to identify the size and concentration of the particles within the suspension. Successful separation of the NPs was effected and the limits of the instrument were obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. 冷等离子体诱导生物分子自组装制备生物材料研究进展%Perspective on cold plasma-induced self-assembly biomolecules approach to biomaterials

    Institute of Scientific and Technical Information of China (English)

    潘云翔; 孙正庆; 段明宇; 刘昌俊

    2015-01-01

    The biomaterials are promising for water treatment, gas sensor, energy storage and photocatalysis. However, the traditional preparation processes of the biomaterials are complex, and require toxic organic reagents. Simple and green preparation methods for biomaterials are highly desired. The cold plasma-induced self-assembly of biomolecules at room temperature is simple and green, as it does not use organic reagent, and does not require calcinations, H2 reduction, chemical reduction and photoinduced reduction. By using the plasma-induced self-assembly, biofilm with a height of(1.03±0.14)nm and metal/biomaterial composites with highly dispersed metal nanoparticles (< 10 nm) have been successfully fabricated. However, many fundamental issues about the cold plasma-induced self-assembly, especially its mechanism, are still unsolved. A deep understanding on these problems will allow for controllable and massive syntheses of biomaterials.%生物材料在污水处理、气体检测、储能、光催化等领域展现出良好的应用前景。但传统生物材料制备方法复杂,且使用高毒性有机溶剂。实现简单、绿色的生物材料制备是目前亟需解决的问题。室温下冷等离子体诱导生物分子自组装制备生物材料,不需有机溶剂,不需高温焙烧、H2还原、化学还原和光致还原,实现了生物材料制备过程的简单化、绿色化。通过冷等离子体诱导生物分子自组装已制备出厚度为(1.03±0.14)nm 的生物膜以及含有尺寸小于10 nm、分散性极好的金属纳米颗粒的金属/生物复合材料。但相关研究刚起步,许多科学问题仍然未知,特别是冷等离子体诱导生物分子自组装机理需进一步研究。这些科学问题一旦得到完美诠释,必定会实现生物材料的可控、宏量制备。

  8. Sabot assembly

    Energy Technology Data Exchange (ETDEWEB)

    Bzorgi, Fariborz

    2016-11-08

    A sabot assembly includes a projectile and a housing dimensioned and configured for receiving the projectile. An air pressure cavity having a cavity diameter is disposed between a front end and a rear end of the housing. Air intake nozzles are in fluid communication with the air pressure cavity and each has a nozzle diameter less than the cavity diameter. In operation, air flows through the plurality of air intake nozzles and into the air pressure cavity upon firing of the projectile from a gun barrel to pressurize the air pressure cavity for assisting in separation of the housing from the projectile upon the sabot assembly exiting the gun barrel.

  9. Assembly of infectious HIV-1 in human epithelial and T-lymphoblastic cell lines.

    Science.gov (United States)

    Grigorov, Boyan; Arcanger, Fabienne; Roingeard, Philippe; Darlix, Jean-Luc; Muriaux, Delphine

    2006-06-16

    The canonical view of the ultimate steps of HIV-1 replication is that virus assembly and budding are taking place at the plasma membrane of infected cells. Surprisingly, recent studies revealed that these steps also occur on endosomal membranes in the interior of infected cells, such as macrophages. This prompted us to revisit the site of HIV-1 assembly in human epithelial-like cells and in infected human T-lymphoblastic cells. To address this question, we investigated the intracellular location of the major viral structural components of HIV-1, namely Gag, Env and the genomic RNA. Using a sub-cellular fractionation method, as well as immuno-confocal and electron microscopy, we show that Gag, the Env glycoproteins and the genomic RNA accumulate in late endosomes that contain infectious HIV-1 particles. In epithelial-like 293T cells, HIV-1 assembles and buds both at the plasma membrane and in endosomes, while in chronically infected human T lymphocytes, viral assembly mostly occurs within the cell where large amounts of infectious virions accumulate in endosomal compartments. In addition, HIV-1 release could be enhanced by ionomycin, a drug stimulating calcium-dependent exocytosis. These results favour the view that newly made Gag molecules associate with the genomic RNA in the cytosol, then viral core complexes can be targeted to late endosomes together with Env, where infectious HIV-1 are made and subsequently released by exocytosis.

  10. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies...... societies. This is an essential reading for both seasoned scholars and advanced students of markets, economies and social forms of consumption....

  11. CATIA-V 3D Modeling for Design Integration of the Ignitor Machine Load Assembly^*

    Science.gov (United States)

    Bianchi, A.; Parodi, B.; Gardella, F.; Coppi, B.

    2007-11-01

    In the framework of the ANSALDO industrial contribution to the Ignitor engineering design, the detailed design of all components of the machine core (Load Assembly) has been completed. The machine Central Post, Central Solenoid, and Poloidal Field Coil systems, the Plasma Chamber and First Wall system, the surrounding mechanical structures, the Vacuum Cryostat and the polyethylene boron sheets attached to it for neutron shielding, have all been analyzed to confirm that they can withstand both normal and off-normal operating loads, as well as the Plasma Chamber and First Wall baking operations, with proper safety margins, for the maximum plasma parameters scenario at 13 T/11 MA, for the reduced scenarios at 9 T/7 MA (limiter) and at 9 T/6 MA (double nul). Both 3D and 2D drawings of each individual component have been produced using the Dassault Systems CATIA-V software. After they have been all integrated into a single 3D CATIA model of the Load Assembly, the electro-fluidic and fluidic lines which supply electrical currents and helium cooling gas to the coils have been added and mechanically incorporated with the components listed above. A global seismic analysis of the Load Assembly with SSE/OBE response spectra has also been performed to verify that it is able to withstand such external events. ^*Work supported in part by ENEA of italy and by the US D.O.E.

  12. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2010-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  13. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2008-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  14. Dump assembly

    Science.gov (United States)

    Goldmann, Louis H.

    1986-01-01

    A dump assembly having a fixed conduit and a rotatable conduit provided with overlapping plates, respectively, at their adjacent ends. The plates are formed with openings, respectively, normally offset from each other to block flow. The other end of the rotatable conduit is provided with means for securing the open end of a filled container thereto. Rotation of the rotatable conduit raises and inverts the container to empty the contents while concurrently aligning the conduit openings to permit flow of material therethrough.

  15. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...

  16. Stirring Unmagnetized Plasma

    CERN Document Server

    Collins, C; Wallace, J; Jara-Almonte, J; Reese, I; Zweibel, E; Forest, C B; 10.1103/PhysRevLett.108.115001

    2012-01-01

    A new concept for spinning unmagnetized plasma is demonstrated experimentally. Plasma is confined by an axisymmetric multi-cusp magnetic field and biased cathodes are used to drive currents and impart a torque in the magnetized edge. Measurements show that flow viscously couples momentum from the magnetized edge (where the plasma viscosity is small) into the unmagnetized core (where the viscosity is large) and that the core rotates as a solid body. To be effective, collisional viscosity must overcome the ion-neutral drag due to charge exchange collisions.

  17. Ice Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice...

  18. Core BPEL

    DEFF Research Database (Denmark)

    Hallwyl, Tim; Højsgaard, Espen

    extensions. Combined with the fact that the language definition does not provide a formal semantics, it is an arduous task to work formally with the language (e.g. to give an implementation). In this paper we identify a core subset of the language, called Core BPEL, which has fewer and simpler constructs......, does not allow omissions, and does not contain ignorable elements. We do so by identifying syntactic sugar, including default values, and ignorable elements in WS-BPEL. The analysis results in a translation from the full language to the core subset. Thus, we reduce the effort needed for working...... formally with WS-BPEL, as one, without loss of generality, need only consider the much simpler Core BPEL. This report may also be viewed as an addendum to the WS-BPEL standard specification, which clarifies the WS-BPEL syntax and presents the essential elements of the language in a more concise way...

  19. Core BPEL

    DEFF Research Database (Denmark)

    Hallwyl, Tim; Højsgaard, Espen

    extensions. Combined with the fact that the language definition does not provide a formal semantics, it is an arduous task to work formally with the language (e.g. to give an implementation). In this paper we identify a core subset of the language, called Core BPEL, which has fewer and simpler constructs......, does not allow omissions, and does not contain ignorable elements. We do so by identifying syntactic sugar, including default values, and ignorable elements in WS-BPEL. The analysis results in a translation from the full language to the core subset. Thus, we reduce the effort needed for working...... formally with WS-BPEL, as one, without loss of generality, need only consider the much simpler Core BPEL. This report may also be viewed as an addendum to the WS-BPEL standard specification, which clarifies the WS-BPEL syntax and presents the essential elements of the language in a more concise way...

  20. Core benefits

    National Research Council Canada - National Science Library

    Keith, Brian W

    2010-01-01

    This SPEC Kit explores the core employment benefits of retirement, and life, health, and other insurance -benefits that are typically decided by the parent institution and often have significant governmental regulation...

  1. MOX fuel arrangement for nuclear core

    Science.gov (United States)

    Kantrowitz, Mark L.; Rosenstein, Richard G.

    1998-01-01

    In order to use up a stockpile of weapons-grade plutonium, the plutonium is converted into a mixed oxide (MOX) fuel form wherein it can be disposed in a plurality of different fuel assembly types. Depending on the equilibrium cycle that is required, a predetermined number of one or more of the fuel assembly types are selected and arranged in the core of the reactor in accordance with a selected loading schedule. Each of the fuel assemblies is designed to produce different combustion characteristics whereby the appropriate selection and disposition in the core enables the resulting equilibrium cycle to closely resemble that which is produced using urania fuel. The arrangement of the MOX rods and burnable absorber rods within each of the fuel assemblies, in combination with a selective control of the amount of plutonium which is contained in each of the MOX rods, is used to tailor the combustion characteristics of the assembly.

  2. 3D solutions of the Poisson-Vlasov equations for a charged plasma and particle-core model in a line of FODO cells

    Science.gov (United States)

    Turchetti, G.; Rambaldi, S.; Bazzani, A.; Comunian, M.; Pisent, A.

    2003-09-01

    We consider a charged plasma of positive ions in a periodic focusing channel of quadrupolar magnets in the presence of RF cavities. The ions are bunched into charged triaxial ellipsoids and their description requires the solution of a fully 3D Poisson-Vlasov equation. We also analyze the trajectories of test particles in the exterior of the ion bunches in order to estimate their diffusion rate. This rate is relevant for a high intensity linac (TRASCO project). A numerical PIC scheme to integrate the Poisson-Vlasov equations in a periodic focusing system in 2 and 3 space dimensions is presented. The scheme consists of a single particle symplectic integrator and a Poisson solver based on FFT plus tri-diagonal matrix inversion. In the 2D version arbitrary boundary conditions can be chosen. Since no analytical self-consistent 3D solution is known, we chose an initial Neuffer-KV distribution in phase space, whose electric field is close to the one generated by a uniformly filled ellipsoid. For a matched (periodic) beam the orbits of test particles moving in the field of an ellipsoidal bunch, whose semi-axis satisfy the envelope equations, is similar to the orbits generated by the self-consistent charge distribition obtained from the PIC simulation, even though it relaxes to a Fermi-Dirac-like distribution. After a transient the RMS radii and emittances have small amplitude oscillations. The PIC simulations for a mismatched (quasiperiodic) beam are no longer comparable with the ellipsoidal bunch model even though the qualitative behavior is the same, namely a stronger diffusion due to the increase of resonances.

  3. 3D solutions of the Poisson-Vlasov equations for a charged plasma and particle-core model in a line of FODO cells

    Energy Technology Data Exchange (ETDEWEB)

    Turchetti, G.; Rambaldi, S.; Bazzani, A. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126, Bologna (Italy); Comunian, M.; Pisent, A. [INFN Laboratori Nazionali di Legnaro (Italy)

    2003-09-01

    We consider a charged plasma of positive ions in a periodic focusing channel of quadrupolar magnets in the presence of RF cavities. The ions are bunched into charged triaxial ellipsoids and their description requires the solution of a fully 3D Poisson-Vlasov equation. We also analyze the trajectories of test particles in the exterior of the ion bunches in order to estimate their diffusion rate. This rate is relevant for a high intensity linac (TRASCO project). A numerical PIC scheme to integrate the Poisson-Vlasov equations in a periodic focusing system in 2 and 3 space dimensions is presented. The scheme consists of a single particle symplectic integrator and a Poisson solver based on FFT plus tri-diagonal matrix inversion. In the 2D version arbitrary boundary conditions can be chosen. Since no analytical self-consistent 3D solution is known, we chose an initial Neuffer-KV distribution in phase space, whose electric field is close to the one generated by a uniformly filled ellipsoid. For a matched (periodic) beam the orbits of test particles moving in the field of an ellipsoidal bunch, whose semi-axis satisfy the envelope equations, is similar to the orbits generated by the self-consistent charge distribution obtained from the PIC simulation, even though it relaxes to a Fermi-Dirac-like distribution. After a transient the RMS radii and emittances have small amplitude oscillations. The PIC simulations for a mismatched (quasiperiodic) beam are no longer comparable with the ellipsoidal bunch model even though the qualitative behavior is the same, namely a stronger diffusion due to the increase of resonances. (orig.)

  4. Chimeric hepatitis B virus core particles with parts or copies of the hepatitis C virus core protein.

    OpenAIRE

    Yoshikawa, A.; Tanaka, T; Hoshi, Y.; Kato, N; K. Tachibana; Iizuka, H; Machida, A; Okamoto, H; Yamasaki, M.; Miyakawa, Y

    1993-01-01

    Either parts or multiple copies of the core gene of hepatitis C virus (HCV) were fused to the 3' terminus of the hepatitis B virus (HBV) core gene with 34 codons removed. As many as four copies of HCV core protein (720 amino acids) were fused to the carboxy terminus of truncated HBV core protein (149 amino acids) without preventing the assembly of HBV core particles. Chimeric core particles were sandwiched between monoclonal antibody to HBV core and that to HCV core, thereby indicating that a...

  5. Chimeric hepatitis B virus core particles with parts or copies of the hepatitis C virus core protein.

    OpenAIRE

    Yoshikawa, A.; Tanaka, T; Hoshi, Y.; Kato, N.; Tachibana, K; Iizuka, H.; Machida, A; Okamoto, H; Yamasaki, M.; Miyakawa, Y

    1993-01-01

    Either parts or multiple copies of the core gene of hepatitis C virus (HCV) were fused to the 3' terminus of the hepatitis B virus (HBV) core gene with 34 codons removed. As many as four copies of HCV core protein (720 amino acids) were fused to the carboxy terminus of truncated HBV core protein (149 amino acids) without preventing the assembly of HBV core particles. Chimeric core particles were sandwiched between monoclonal antibody to HBV core and that to HCV core, thereby indicating that a...

  6. General Assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : 1- Adoption de l’ordre du jour. 2- Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. 3- Présentation et approbation du rapport d’activités 2014. 4- Présentation et approbation du rapport financier 2014. 5- Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. 6- Programme 2015. 7- Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. 8- Pas de modifications aux Statuts de l'Association du personnel proposée. 9- Élections des membres de la Commission é...

  7. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    Mardi 5 avril à 11 h 00 BE Auditorium Meyrin (6-2-024) Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 mai 2015. Présentation et approbation du rapport d’activités 2015. Présentation et approbation du rapport financier 2015. Présentation et approbation du rapport des vérificateurs aux comptes pour 2015. Programme de travail 2016. Présentation et approbation du projet de budget 2016 Approbation du taux de cotisation pour 2017. Modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commissio...

  8. General assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. Présentation et approbation du rapport d’activités 2014. Présentation et approbation du rapport financier 2014. Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. Programme 2015. Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. Pas de modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commission électorale. &am...

  9. General Assembly

    CERN Multimedia

    Staff Association

    2017-01-01

    Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 avril 2016. Présentation et approbation du rapport d’activités 2016. Présentation et approbation du rapport financier 2016. Présentation et approbation du rapport des vérificateurs aux comptes pour 2016. Programme de travail 2017. Présentation et approbation du projet de budget 2017 Approbation du taux de cotisation pour 2018. Modifications aux Statuts de l'Association du personnel proposées. Élections des membres de la Commission électorale. Élections des vérifica...

  10. High temperature superconductors for fusion at the Swiss Plasma Center

    Science.gov (United States)

    Bruzzone, P.; Wesche, R.; Uglietti, D.; Bykovsky, N.

    2017-08-01

    High temperature superconductors (HTS) may become in future an option for the superconducting magnets of commercial fusion plants. At the Swiss Plasma Center (SPC) the R&D activity toward HTS high current, high field cables suitable for fusion magnets started in 2012 and led in 2015 to the assembly of the first 60 kA, 12 T prototype conductor. The cable concept developed at the SPC is based on the principle of ‘soldered, twisted stacks’ of REBCO tapes. The required number of stacks is assembled in a cored flat cable, cooled by forced flow of supercritical helium. The sample environment of the test facility at SPC has been upgraded with a HTS adapter and a counter-flow heat exchanger to allow testing the HTS sample in a broader range of temperature (4.5 K-50 K) using the existing, NbTi based superconducting transformer and the closed loop refrigerator.

  11. Electrical transport properties in Fe-Cr nanocluster-assembled granular films

    Science.gov (United States)

    Wang, Xiong-Zhi; Wang, Lai-Sen; Zhang, Qin-Fu; Liu, Xiang; Xie, Jia; Su, A.-Mei; Zheng, Hong-Fei; Peng, Dong-Liang

    2017-09-01

    The Fe100-xCrx nanocluster-assembled granular films with Cr atomic fraction (x) ranging from 0 to 100 were fabricated by using a plasma-gas-condensation cluster deposition system. The TEM characterization revealed that the uniform Fe clusters were coated with a Cr layer to form a Fe-Cr core-shell structure. Then, the as-prepared Fe100-xCrx nanoclusters were randomly assembled into a granular film in vacuum environments with increasing the deposition time. Because of the competition between interfacial resistance and shunting effect of Cr layer, the room temperature resistivity of the Fe100-xCrx nanocluster-assembled granular films first increased and then decreased with increasing the Cr atomic fraction (x), and revealed a maximum of 2 × 104 μΩ cm at x = 26 at.%. The temperature-dependent longitudinal resistivity (ρxx), magnetoresistance (MR) effect and anomalous Hall effect (AHE) of these Fe100-xCrx nanocluster-assembled granular films were also studied systematically. As the x increased from 0 to 100, the ρxx of all samples firstly decreased and then increased with increasing the measuring temperature. The dependence of ρxx on temperature could be well addressed by a mechanism incorporated for the fluctuation-induced-tunneling (FIT) conduction process and temperature-dependent scattering effect. It was found that the anomalous Hall effect (AHE) had no legible scaling relation in Fe100-xCrx nanocluster-assembled granular films. However, after deducting the contribution of tunneling effect, the scaling relation was unambiguous. Additionally, the Fe100-xCrx nanocluster-assembled granular films revealed a small negative magnetoresistance (MR), which decreased with the increase of x. The detailed physical mechanism of the electrical transport properties in these Fe100-xCrx nanocluster-assembled granular films was also studied.

  12. Whole Core Transport Calculation Methodology for a Hexagonal Core

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J. Y.; Kim, K. S.; Lee, C. C.; Zee, S. Q.; Joo, H. G

    2007-07-15

    This report discusses the hexagonal module implemented to the DeCART code and the performance of them. The implemented hexagonal module includes the hexagonal ray tracing and the CMFD acceleration modules. The performance of the implemented hexagonal module is examined for 4 tests of: (1) CMFD acceleration test, (2) the accuracy test of the hexagonal module, (3) the performance test for 2-D NGNP problem and (4) the applicability test for 3-D NGNP problem. The features of the implemented hexagonal modules are: (1) The Modular ray tracing scheme based on a hexagonal assembly and a path linking scheme between the modular rays. (2) Segment generation based on the structure unit. (3) Cell ray approximation: This feature is developed to reduce the memory required to store the segment information. (4) Modified cycle ray scheme that begins the ray tracing at a given surface and finishes if the reflected ray meets the starting surface. This feature is developed to reduce the memory required for the angular flux at the core boundary. (5) Fixed assembly geometry. The pin geometry of the single pin per assembly problem is different from that of the multi-pin problem. The core geometry of a single assembly problem is also different from that of the multi-assembly problem. (6) CMFD module based on unstructured cell. This feature is to deal with the irregular gap cells that are positioned at the assembly boundaries. The examination results of the 4 tests can be summarized as: (1) The CMFD acceleration test shows that the CMFD module speedups about greater than 200 for the core problem. (2) The accuracy test shows that the hexagonal MOC module produces an accurate solution of less than 60 pcm of eigenvalue and less than 2 % of local pin power errors. (3) The performance test for 2-D NGNP problem shows that the implemented hexagonal module works soundly and produces a reasonable solution by cooperating with the existing DeCART library and the other modules. (4) The applicability

  13. Advantages of iron core in a tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Bettis, E.S.; Ballou, J.K.; Becraft, W.R.; Peng, Y.K.M.; Watts, H.L.

    1977-01-01

    A quantitative comparison of the iron core vs air core concepts was carried out on a preliminary basis by using a representative tokamak reactor design with the following self-consistent reference parameters. In the area of plasma engineering, poloidal field and MHD equilibrium considerations with an unsaturated iron core is discussed. The question of proper poloidal field coils to maintain D-shaped plasmas of relatively high anti ..beta.. (7%) with a saturated iron core is also discussed. Estimates of the required iron core size, volt seconds, magnetic flux and its influence on force loading on the superconducting toroidal field coils are shown. Conceptual designs of the mechanical structure of an iron core device are presented. Favorable impacts on the OH power supply cost and complexity are indicated.

  14. HIV-1 assembly in macrophages

    Directory of Open Access Journals (Sweden)

    Benaroch Philippe

    2010-04-01

    Full Text Available Abstract The molecular mechanisms involved in the assembly of newly synthesized Human Immunodeficiency Virus (HIV particles are poorly understood. Most of the work on HIV-1 assembly has been performed in T cells in which viral particle budding and assembly take place at the plasma membrane. In contrast, few studies have been performed on macrophages, the other major target of HIV-1. Infected macrophages represent a viral reservoir and probably play a key role in HIV-1 physiopathology. Indeed macrophages retain infectious particles for long periods of time, keeping them protected from anti-viral immune response or drug treatments. Here, we present an overview of what is known about HIV-1 assembly in macrophages as compared to T lymphocytes or cell lines. Early electron microscopy studies suggested that viral assembly takes place at the limiting membrane of an intracellular compartment in macrophages and not at the plasma membrane as in T cells. This was first considered as a late endosomal compartment in which viral budding seems to be similar to the process of vesicle release into multi-vesicular bodies. This view was notably supported by a large body of evidence involving the ESCRT (Endosomal Sorting Complex Required for Transport machinery in HIV-1 budding, the observation of viral budding profiles in such compartments by immuno-electron microscopy, and the presence of late endosomal markers associated with macrophage-derived virions. However, this model needs to be revisited as recent data indicate that the viral compartment has a neutral pH and can be connected to the plasma membrane via very thin micro-channels. To date, the exact nature and biogenesis of the HIV assembly compartment in macrophages remains elusive. Many cellular proteins potentially involved in the late phases of HIV-1 cycle have been identified; and, recently, the list has grown rapidly with the publication of four independent genome-wide screens. However, their respective

  15. Development of plasma sources for ICRF heating experiment in KMAX mirror device

    Science.gov (United States)

    Sun, Xuan; Liu, Ming; Yi, Hongshen; Lin, Munan; Shi, Peiyun

    2016-10-01

    KMAX, Keda Mirror with AXisymmeticity, is a tandem mirror machine with a length of 10 meters and diameters of 1.2 meters in the central cell and 0.3 meters in the mirror throat. In the past experiments, the plasma was generated by helicon wave launched from the west end. We obtained the blue core mode in argon discharge, however, it cannot provide sufficient plasma for hydrogen discharge, which is at least 1012 cm-3 required for effective ICRF heating. Several attempts have thus been tried or under design to increase the central cell's plasma density: (1) a washer gun with aperture of 1cm has been successfully tested, and a plasma density of 1013 cm-3 was achieved in the west cell near the gun, however, the plasma is only 1011 cm-3 in the central cell possible due to the mirror trapping and/or neutral quenching effect (2) a larger washer gun with aperture of 2.5 cm and a higher power capacitor bank are being assembled in order to generate more plasmas. In addition, how to mitigate the neutrals is under consideration (3) A hot cathode is been designed and will be tested in combination with plasma gun or alone. Preliminary results from those plasma sources will be presented and discussed.

  16. Seismic response of nuclear fuel assembly

    Directory of Open Access Journals (Sweden)

    Hlaváč Z.

    2014-06-01

    Full Text Available The paper deals with mathematical modelling and computer simulation of the seismic response of fuel assembly components. The seismic response is investigated by numerical integration method in time domain. The seismic excitation is given by two horizontal and one vertical synthetic accelerograms at the level of the pressure vessel seating. Dynamic response of the hexagonal type nuclear fuel assembly is caused by spatial motion of the support plates in the reactor core investigated on the reactor global model. The modal synthesis method with condensation is used for calculation of the fuel assembly component displacements and speeds on the level of the spacer grid cells.

  17. Core Java

    CERN Document Server

    Horstmann, Cay S

    2013-01-01

    Fully updated to reflect Java SE 7 language changes, Core Java™, Volume I—Fundamentals, Ninth Edition, is the definitive guide to the Java platform. Designed for serious programmers, this reliable, unbiased, no-nonsense tutorial illuminates key Java language and library features with thoroughly tested code examples. As in previous editions, all code is easy to understand, reflects modern best practices, and is specifically designed to help jumpstart your projects. Volume I quickly brings you up-to-speed on Java SE 7 core language enhancements, including the diamond operator, improved resource handling, and catching of multiple exceptions. All of the code examples have been updated to reflect these enhancements, and complete descriptions of new SE 7 features are integrated with insightful explanations of fundamental Java concepts.

  18. Complex coacervate core micelles.

    Science.gov (United States)

    Voets, Ilja K; de Keizer, Arie; Cohen Stuart, Martien A

    2009-01-01

    In this review we present an overview of the literature on the co-assembly of neutral-ionic block, graft, and random copolymers with oppositely charged species in aqueous solution. Oppositely charged species include synthetic (co)polymers of various architectures, biopolymers - such as proteins, enzymes and DNA - multivalent ions, metallic nanoparticles, low molecular weight surfactants, polyelectrolyte block copolymer micelles, metallo-supramolecular polymers, equilibrium polymers, etcetera. The resultant structures are termed complex coacervate core/polyion complex/block ionomer complex/interpolyelectrolyte complex micelles (or vesicles); i.e., in short C3Ms (or C3Vs) and PIC, BIC or IPEC micelles (and vesicles). Formation, structure, dynamics, properties, and function will be discussed. We focus on experimental work; theory and modelling will not be discussed. Recent developments in applications and micelles with heterogeneous coronas are emphasized.

  19. SMART core protection system design

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. K.; Park, H. Y.; Koo, I. S. [KAERI, Taejon (Korea, Republic of); Park, H. S.; Kim, J. S.; Son, C. H. [Samchang Enterprise Co., Ltd., Taejon (Korea, Republic of)

    2003-10-01

    SMART COre Protection System(SCOPS) is designed with real-tims Digital Signal Processor(DSP) board and Network Interface Card(NIC) board. SCOPS has a Control Rod POSition (CRPOS) software module while Core Protection Calculator System(CPCS) consists of Core Protection Calculators(CPCs) and Control Element Assembly(CEA) Calculators(CEACs) in the commercial nuclear plant. It's not necessary to have a independent cabinets for SCOPS because SCOPS is physically very small. Then SCOPS is designed to share the cabinets with Plant Protection System(PPS) of SMART. Therefor it's very easy to maintain the system because CRPOS module is used instead of the computer with operating system.

  20. Power Generation Capabilities of Tie Tube Assemblies

    Science.gov (United States)

    Gunn, Stanley V.; Hedstrom, James; Hundal, Rolv

    1994-07-01

    Second generation nuclear thermal rocket engine designs, employing solid core reactors and expander engine cycles, generally rely on some form of nuclear-driven heater to supply the major portion of thermal energy required to preheat the turbine-drive gases. If adequate heat transfer occurs, not only will efficiency-enhancing turbine-inlet temperatures be realized, but sufficient energy will be available to enable engine operation at chamber pressures ranging to at least 2,000 psia. For the case of reactor cores employing prismatic fuel elements, the utilization of tie tube assemblies, as first employed in the core-support subsystem of the Phoebus II reactor, can provide the basis of an array of propellant (hydrogen) preheaters that offer an ample supply of energy and temperature to enable candidate expander engine cycles over a wide range of operating parameters, without reducing the total enthalpy of the core-exit gas and its attendant effect on specific impulse. By modifying the tie tube design concept set forth in LASL's Nuclear Rocket Engine definition study, a powerful, weight and packaging-effective, preheater assembly can be realized. The design features of these tie tube assemblies reflect their functional objectives, core criticality considerations, and space constraints. Since the core pressure and inertial mass loads are carried by these assemblies, the structural tubular element(s) also provide coolant passage(s) for the hydrogen. The transfer of heat to the coolant surfaces is controlled by the effective thermal conductivity of the filler structure and ``insulating sleeves,'' which surround the tubular elements and are in controlled thermal contact with the surrounding core fuel elements. An option exists to further increase the transported heat to the coolant walls by the selective loading of the filler structure, ``insulating sleeves,'' and the moderator annular element with fissionable material.

  1. Mechanisms of centrosome separation and bipolar spindle assembly.

    Science.gov (United States)

    Tanenbaum, Marvin E; Medema, René H

    2010-12-14

    Accurate segregation of chromosomes during cell division is accomplished through the assembly of a bipolar microtubule-based structure called the mitotic spindle. Work over the past two decades has identified a core regulator of spindle bipolarity, the microtubule motor protein kinesin-5. However, an increasing body of evidence has emerged demonstrating that kinesin-5-independent mechanisms driving bipolar spindle assembly exist as well. Here, we discuss different pathways that promote initial centrosome separation and bipolar spindle assembly.

  2. Inventory control: cytochrome c oxidase assembly regulates mitochondrial translation.

    Science.gov (United States)

    Mick, David U; Fox, Thomas D; Rehling, Peter

    2011-01-01

    Mitochondria maintain genome and translation machinery to synthesize a small subset of subunits of the oxidative phosphorylation system. To build up functional enzymes, these organellar gene products must assemble with imported subunits that are encoded in the nucleus. New findings on the early steps of cytochrome c oxidase assembly reveal how the mitochondrial translation of its core component, cytochrome c oxidase subunit 1 (Cox1), is directly coupled to the assembly of this respiratory complex.

  3. Inventory control: cytochrome oxidase assembly regulates mitochondrial translation

    Science.gov (United States)

    Mick, David U.; Fox, Thomas D.; Rehling, Peter

    2012-01-01

    Mitochondria maintain a genome and translation-machinery to synthesize a small subset of subunits of the oxidative phosphorylation system. These organellar gene products must assemble with imported subunits that are encoded in the nucleus to build up functional enzymes. New findings on the early steps in cytochrome oxidase assembly reveal how the mitochondrial translation of its core component Cox1 is directly coupled to the assembly of this respiratory complex. PMID:21179059

  4. Composite nozzle design for reactor fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Marlatt, G.R.; Allison, D.K.

    1984-01-24

    A composite nozzle is described for a fuel assembly adapted for installation on the upper or lower end thereof and which is constructed from two components. The first component includes a casting weldment or forging designed to carry handling loads, support fuel assembly weight and flow loads, and interface with structural members of both the fuel assembly and reactor internal structures. The second component of the nozzle consists of a thin stamped bore machine flow plate adapted for attachment to the casting body. The plate is designed to prevent fuel rods from being ejected from the core and provide orifices for coolant flow to a predetermined value and pressure drop which is consistent with the flow at other locations in the core.

  5. A solution for automatic parallelization of sequential assembly code

    Directory of Open Access Journals (Sweden)

    Kovačević Đorđe

    2013-01-01

    Full Text Available Since modern multicore processors can execute existing sequential programs only on a single core, there is a strong need for automatic parallelization of program code. Relying on existing algorithms, this paper describes one new software solution tool for parallelization of sequential assembly code. The main goal of this paper is to develop the parallelizator which reads sequential assembler code and at the output provides parallelized code for MIPS processor with multiple cores. The idea is the following: the parser translates assembler input file to program objects suitable for further processing. After that the static single assignment is done. Based on the data flow graph, the parallelization algorithm separates instructions on different cores. Once sequential code is parallelized by the parallelization algorithm, registers are allocated with the algorithm for linear allocation, and the result at the end of the program is distributed assembler code on each of the cores. In the paper we evaluate the speedup of the matrix multiplication example, which was processed by the parallelizator of assembly code. The result is almost linear speedup of code execution, which increases with the number of cores. The speed up on the two cores is 1.99, while on 16 cores the speed up is 13.88.

  6. Probe tip heating assembly

    Science.gov (United States)

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  7. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  8. Nuclear reactor composite fuel assembly. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, D.M.; Cappiello, M.W.; Marr, D.R.; Omberg, R.P.

    1980-11-25

    A core and composite fuel assembly are described for a liquid-cooled breeder nuclear reactor including a plurality of elongated coextending driver and breeder fuel elements arranged to form a generally polygonal bundle within a thin-walled duct. The breeder elements are larger in cross section than the driver elements, and each breeder element is laterally bounded by a number of the driver elements. Each driver element further includes structure for spacing the driver elements from adjacent fuel elements and, where adjacent, the thin-walled duct. A core made up of the fuel elements can advantageously include fissile fuel of only one enrichment, while varying the effective enrichment of any given assembly or core region, merely by varying the relative number and size of the driver and breeder elements.

  9. Turbulent transport in magnetized plasmas

    CERN Document Server

    Horton, Wendell

    2012-01-01

    This book explains how magnetized plasmas self-organize in states of electromagnetic turbulence that transports particles and energy out of the core plasma faster than anticipated by the fusion scientists designing magnetic confinement systems in the 20th century. It describes theory, experiments and simulations in a unified and up-to-date presentation of the issues of achieving nuclear fusion power.

  10. Core transport studies in fusion devices

    CERN Document Server

    Strand, Pär; Nordman, Hans

    2010-01-01

    The turbulence in magnetically confined fusion plasmas has important and non-trivial effects on the quality of the energy confinement. These effects are hard to make a quantitative assessment of analytically. The problem investigated in this article is the transport of energy and particles, in particular impurities, in a Tokamak plasma. Impurities from the walls of the plasma vessel cause energy losses if they reach the plasma core. It is therefore important to understand the transport mechanisms to prevent impurity accumulation and minimize losses. This is an area of research where turbulence plays a major role and is intimately associated with the performance of future fusion reactors, such as ITER.

  11. Electrostatic-Induced Assembly of Graphene-Encapsulated Carbon@Nickel-Aluminum Layered Double Hydroxide Core-Shell Spheres Hybrid Structure for High-Energy and High-Power-Density Asymmetric Supercapacitor.

    Science.gov (United States)

    Wu, Shuxing; Hui, Kwan San; Hui, Kwun Nam; Kim, Kwang Ho

    2017-01-18

    Achieving high energy density while retaining high power density is difficult in electrical double-layer capacitors and in pseudocapacitors considering the origin of different charge storage mechanisms. Rational structural design became an appealing strategy in circumventing these trade-offs between energy and power densities. A hybrid structure consists of chemically converted graphene-encapsulated carbon@nickel-aluminum layered double hydroxide core-shell spheres as spacers among graphene layers (G-CLS) used as an advanced electrode to achieve high energy density while retaining high power density for high-performance supercapacitors. The merits of the proposed architecture are as follows: (1) CLS act as spacers to avoid the close restacking of graphene; (2) highly conductive carbon sphere and graphene preserve the mechanical integrity and improve the electrical conductivity of LDHs hybrid. Thus, the proposed hybrid structure can simultaneously achieve high electrical double-layer capacitance and pseudocapacitance resulting in the overall highly active electrode. The G-CLS electrode exhibited high specific capacitance (1710.5 F g(-1) at 1 A g(-1)) under three-electrode tests. An ASC fabricated using the G-CLS as positive electrode and reduced graphite oxide as negative electrode demonstrated remarkable electrochemical performance. The ASC device operated at 1.4 V and delivered a high energy density of 35.5 Wh kg(-1) at a 670.7 W kg(-1) power density at 1 A g(-1) with an excellent rate capability as well as a robust long-term cycling stability of up to 10 000 cycles.

  12. Nanoporous Network Channels from Self-Assembled Triblock Copolymer Supramolecules

    NARCIS (Netherlands)

    du Sart, Gerrit Gobius; Vukovic, Ivana; Vukovic, Zorica; Polushkin, Evgeny; Hiekkataipale, Panu; Ruokolainen, Janne; Loos, Katja; ten Brinke, Gerrit

    2011-01-01

    Supramolecular complexes of a poly(tert-butoxystyrene)-block-polystyrene-block-poly(4-vinylpyridine) triblock copolymers and less than stoichiometric amounts of pentadecylphenol (PDP) are shown to self-assemble into a core-shell gyroid morphology with the core channels formed by the hydrogen-bonded

  13. LMFBR fuel assembly design for HCDA fuel dispersal

    Science.gov (United States)

    Lacko, Robert E.; Tilbrook, Roger W.

    1984-01-01

    A fuel assembly for a liquid metal fast breeder reactor having an upper axial blanket region disposed in a plurality of zones within the fuel assembly. The characterization of a zone is dependent on the height of the axial blanket region with respect to the active fuel region. The net effect of having a plurality of zones is to establish a dispersal flow path for the molten materials resulting during a core meltdown accident. Upward flowing molten material can escape from the core region and/or fuel assembly without solidifying on the surface of fuel rods due to the heat sink represented by blanket region pellets.

  14. Construction and utilization of linear empirical core models for PWR in-core fuel management

    Energy Technology Data Exchange (ETDEWEB)

    Okafor, K.C.

    1988-01-01

    An empirical core-model construction procedure for pressurized water reactor (PWR) in-core fuel management is developed that allows determining the optimal BOC k{sub {infinity}} profiles in PWRs as a single linear-programming problem and thus facilitates the overall optimization process for in-core fuel management due to algorithmic simplification and reduction in computation time. The optimal profile is defined as one that maximizes cycle burnup. The model construction scheme treats the fuel-assembly power fractions, burnup, and leakage as state variables and BOC zone enrichments as control variables. The core model consists of linear correlations between the state and control variables that describe fuel-assembly behavior in time and space. These correlations are obtained through time-dependent two-dimensional core simulations. The core model incorporates the effects of composition changes in all the enrichment control zones on a given fuel assembly and is valid at all times during the cycle for a given range of control variables. No assumption is made on the geometry of the control zones. A scatter-composition distribution, as well as annular, can be considered for model construction. The application of the methodology to a typical PWR core indicates good agreement between the model and exact simulation results.

  15. Recovering core identity, hermeneutical and contextual preaching

    African Journals Online (AJOL)

    2016-07-08

    Jul 8, 2016 ... written with this primarily in mind, they do remind God's people of ... More specifically, is the question of core identity affected by the ministry of ... to be sick because they have a false self-image: 'They have grasped .... word refers to a political assembly of citizens whose task was ..... Memories, hopes, and.

  16. Autonomous electrochromic assembly

    Energy Technology Data Exchange (ETDEWEB)

    Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

    2015-03-10

    This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacity state. The electrochromic assembly may be used in combination with a window.

  17. Process to make core-shell structured nanoparticles

    Science.gov (United States)

    Luhrs, Claudia; Phillips, Jonathan; Richard, Monique N

    2014-01-07

    Disclosed is a process for making a composite material that contains core-shell structured nanoparticles. The process includes providing a precursor in the form of a powder a liquid and/or a vapor of a liquid that contains a core material and a shell material, and suspending the precursor in an aerosol gas to produce an aerosol containing the precursor. In addition, the process includes providing a plasma that has a hot zone and passing the aerosol through the hot zone of the plasma. As the aerosol passes through the hot zone of the plasma, at least part of the core material and at least part of the shell material in the aerosol is vaporized. Vapor that contains the core material and the shell material that has been vaporized is removed from the hot zone of the plasma and allowed to condense into core-shell structured nanoparticles.

  18. Turbulence and cooling in cluster cores

    CERN Document Server

    Banerjee, Nilanjan

    2014-01-01

    We study the interplay between turbulent heating, mixing, and radiative cooling in an idealized model of cool cluster cores. Active galactic nuclei (AGN) jets are expected to drive turbulence and heat cluster cores. Cooling of the intracluster medium (ICM) and stirring by AGN jets are tightly coupled in a feedback loop. We impose the feedback loop by balancing radiative cooling with turbulent heating. In addition to heating the plasma, turbulence also mixes it, suppressing the formation of cold gas at small scales. In this regard, the effect of turbulence is analogous to thermal conduction. For uniform plasma in thermal balance (turbulent heating balancing radiative cooling), cold gas condenses only if the cooling time is shorter than the mixing time. This condition requires the turbulent kinetic energy to be $\\gtrsim$ the plasma internal energy; such high velocities in cool cores are ruled out by observations. The results with realistic magnetic fields and thermal conduction are qualitatively similar to the ...

  19. HANARO core channel flow-rate measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Heon Il; Chae, Hee Tae; Im, Don Soon; Kim, Seon Duk [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-06-01

    HANARO core consists of 23 hexagonal flow tubes and 16 cylindrical flow tubes. To get the core flow distribution, we used 6 flow-rate measuring dummy fuel assemblies (instrumented dummy fuel assemblies). The differential pressures were measured and converted to flow-rates using the predetermined relationship between AP and flow-rate for each instrumented dummy fuel assemblies. The flow-rate for the cylindrical flow channels shows +-7% relative errors and that for the hexagonal flow channels shows +-3.5% relative errors. Generally the flow-rates of outer core channels show smaller values compared to those of inner core. The channels near to the core inlet pipe and outlet pipes also show somewhat lower flow-rates. For the lower flow channels, the thermal margin was checked by considering complete linear power histories. From the experimental results, the gap flow-rate was estimated to be 49.4 kg/s (cf. design flow of 50 kg/s). 15 tabs., 9 figs., 10 refs. (Author) .new.

  20. Beyond core knowledge: Natural geometry

    Science.gov (United States)

    Spelke, Elizabeth; Lee, Sang Ah; Izard, Véronique

    2010-01-01

    For many centuries, philosophers and scientists have pondered the origins and nature of human intuitions about the properties of points, lines, and figures on the Euclidean plane, with most hypothesizing that a system of Euclidean concepts either is innate or is assembled by general learning processes. Recent research from cognitive and developmental psychology, cognitive anthropology, animal cognition, and cognitive neuroscience suggests a different view. Knowledge of geometry may be founded on at least two distinct, evolutionarily ancient, core cognitive systems for representing the shapes of large-scale, navigable surface layouts and of small-scale, movable forms and objects. Each of these systems applies to some but not all perceptible arrays and captures some but not all of the three fundamental Euclidean relationships of distance (or length), angle, and direction (or sense). Like natural number (Carey, 2009), Euclidean geometry may be constructed through the productive combination of representations from these core systems, through the use of uniquely human symbolic systems. PMID:20625445

  1. The Cores of Elliptical Galaxies in Coma

    Science.gov (United States)

    Lucey, John

    1995-07-01

    The cores of galaxies are astrophysically unique. They canhost high energy nuclei, star formation and perhaps even blackholes. HST observations have established that the cores ofellipticals are related to their global properties, and so canbe used as diagnostics of the physical processes occurring atthe time of formation. HST images of galaxy cores havedistinguished two different types of core luminosity profiles:`soft' and `hard' types. It is suggested that luminous, slowlyrotating galaxies have `soft' cores and the less luminousdisky galaxies have `hard' cores. This can be interpreted interms of a formation scenario based on a merger hierarchy inwhich the low luminosity systems experience highly dissipativemergers, but as the luminous systems are assembled the mergersbecome increasingly stellar. In this picture, the type of corea galaxy generates is intimately related to its evolutionaryhistory, i.e. the degree of interaction/merging experiencedand the availability of cold gas. In turn, this should notonly depend on luminosity but also on the galaxy's localenvironment. Here we propose to test the gaseous/stellarmerger picture by imaging a set of Coma cluster ellipticalsfrom a wide range of cluster radii. In the gas poorenvironment of the cluster core there may be insufficent coldgas for the low luminosity galaxies to form `hard' cores.Similarly, at the cluster turnround radius even luminousgalaxies may have experienced a dissipative core formation andpossess

  2. Polymer Directed Protein Assemblies

    NARCIS (Netherlands)

    van Rijn, Patrick

    2013-01-01

    Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e. g., virus particles. Viruses are a multi-protein assembly of which the morphology is

  3. Polymer Directed Protein Assemblies

    NARCIS (Netherlands)

    van Rijn, Patrick

    Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e. g., virus particles. Viruses are a multi-protein assembly of which the morphology is

  4. Modeling of Parameters of Subcritical Assembly SAD

    CERN Document Server

    Petrochenkov, S; Puzynin, I

    2005-01-01

    The accepted conceptual design of the experimental Subcritical Assembly in Dubna (SAD) is based on the MOX core with a nominal unit capacity of 25 kW (thermal). This corresponds to the multiplication coefficient $k_{\\rm eff} =0.95$ and accelerator beam power 1 kW. A subcritical assembly driven with the existing 660 MeV proton accelerator at the Joint Institute for Nuclear Research has been modelled in order to make choice of the optimal parameters for the future experiments. The Monte Carlo method was used to simulate neutron spectra, energy deposition and doses calculations. Some of the calculation results are presented in the paper.

  5. Quality Experiences in Aerospace Electronic Assembly

    Directory of Open Access Journals (Sweden)

    P.B.V. Rama Murthy

    2006-01-01

    Full Text Available Quality of the electronic assembly depends largely on good quality practices (GQP adoptedduring the process of electronic assembly. Quality experiences gained during working atthe defence and space laboratories have been used to develop good quality practices such asthree- tray method for cleaning of PCBs, use of grommets for cable routing, use of eye-piecelessstereo zoom microscope for visual testinglinspection, pre-tinning of components, desiccatorsfor storage, potting prior to conformal coating, continuity and isolation checks, de-golding ofleads prior to soldering, and use of flux-cored solder wire. The paper also discusses how andwhy these good quality practices were evolved.

  6. SWAP-Assembler 2: Optimization of De Novo Genome Assembler at Large Scale

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Jintao; Seo, Sangmin; Balaji, Pavan; Wei, Yanjie; Wang, Bingqiang; Feng, Shengzhong

    2016-08-16

    In this paper, we analyze and optimize the most time-consuming steps of the SWAP-Assembler, a parallel genome assembler, so that it can scale to a large number of cores for huge genomes with the size of sequencing data ranging from terabyes to petabytes. According to the performance analysis results, the most time-consuming steps are input parallelization, k-mer graph construction, and graph simplification (edge merging). For the input parallelization, the input data is divided into virtual fragments with nearly equal size, and the start position and end position of each fragment are automatically separated at the beginning of the reads. In k-mer graph construction, in order to improve the communication efficiency, the message size is kept constant between any two processes by proportionally increasing the number of nucleotides to the number of processes in the input parallelization step for each round. The memory usage is also decreased because only a small part of the input data is processed in each round. With graph simplification, the communication protocol reduces the number of communication loops from four to two loops and decreases the idle communication time. The optimized assembler is denoted as SWAP-Assembler 2 (SWAP2). In our experiments using a 1000 Genomes project dataset of 4 terabytes (the largest dataset ever used for assembling) on the supercomputer Mira, the results show that SWAP2 scales to 131,072 cores with an efficiency of 40%. We also compared our work with both the HipMER assembler and the SWAP-Assembler. On the Yanhuang dataset of 300 gigabytes, SWAP2 shows a 3X speedup and 4X better scalability compared with the HipMer assembler and is 45 times faster than the SWAP-Assembler. The SWAP2 software is available at https://sourceforge.net/projects/swapassembler.

  7. Sensor mount assemblies and sensor assemblies

    Science.gov (United States)

    Miller, David H [Redondo Beach, CA

    2012-04-10

    Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.

  8. Plasma turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

  9. Heat transfer and core neutronics considerations of the heat pipe cooled thermionic reactor

    Science.gov (United States)

    Determan, W. R.; Lewis, Brian

    1991-01-01

    The authors summarize the results of detailed neutronic and thermal-hydraulic evaluations of the heat pipe cooled thermionic (HPTI) reactor design, identify its key design attributes, and quantify its performance characteristics. The HPTI core uses modular, liquid-metal core heat transfer assemblies to replace the liquid-metal heat transport loop employed by in-core thermionic reactor designs of the past. The nuclear fuel, power conversion, heat transport, and heat rejection functions are all combined into a single modular unit. The reactor/converter assembly uses UN fuel pins to obtain a critical core configuration with in-core safety rods and reflector controls added to complete the subassembly. By thermally bonding the core heat transfer assemblies during the reactor core is coupled neutronically, thermally, and electrically into a modular assembly of individual power sources with cross-tied architecture. A forward-facing heat pipe radiator assembly extends from the reactor head in the shape of a frustum of a cone on the opposite side of the power system from the payload. Important virtues of the concept are the absence of any single-point failures and the ability of the core to effectively transfer the TFE waste heat load laterally to other in-core heat transfer assemblies in the event of multiple failures in either in-core and radiator heat pipes.

  10. Heat transfer and core neutronics considerations of the heat pipe cooled thermionic reactor

    Science.gov (United States)

    Determan, W. R.; Lewis, Brian

    The authors summarize the results of detailed neutronic and thermal-hydraulic evaluations of the heat pipe cooled thermionic (HPTI) reactor design, identify its key design attributes, and quantify its performance characteristics. The HPTI core uses modular, liquid-metal core heat transfer assemblies to replace the liquid-metal heat transport loop employed by in-core thermionic reactor designs of the past. The nuclear fuel, power conversion, heat transport, and heat rejection functions are all combined into a single modular unit. The reactor/converter assembly uses UN fuel pins to obtain a critical core configuration with in-core safety rods and reflector controls added to complete the subassembly. By thermally bonding the core heat transfer assemblies during the reactor core is coupled neutronically, thermally, and electrically into a modular assembly of individual power sources with cross-tied architecture. A forward-facing heat pipe radiator assembly extends from the reactor head in the shape of a frustum of a cone on the opposite side of the power system from the payload. Important virtues of the concept are the absence of any single-point failures and the ability of the core to effectively transfer the TFE waste heat load laterally to other in-core heat transfer assemblies in the event of multiple failures in either in-core and radiator heat pipes.

  11. Dual-core antiresonant hollow core fibers.

    Science.gov (United States)

    Liu, Xuesong; Fan, Zhongwei; Shi, Zhaohui; Ma, Yunfeng; Yu, Jin; Zhang, Jing

    2016-07-25

    In this work, dual-core antiresonant hollow core fibers (AR-HCFs) are numerically demonstrated, based on our knowledge, for the first time. Two fiber structures are proposed. One is a composite of two single-core nested nodeless AR-HCFs, exhibiting low confinement loss and a circular mode profile in each core. The other has a relatively simple structure, with a whole elliptical outer jacket, presenting a uniform and wide transmission band. The modal couplings of the dual-core AR-HCFs rely on a unique mechanism that transfers power through the air. The core separation and the gap between the two cores influence the modal coupling strength. With proper designs, both of the dual-core fibers can have low phase birefringence and short modal coupling lengths of several centimeters.

  12. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  13. Feasibility study on nuclear core design for soluble boron free small modular reactor

    Science.gov (United States)

    Rabir, Mohamad Hairie; Hah, Chang Joo; Ju, Cho Sung

    2015-04-01

    A feasibility study on nuclear core design of soluble boron free (SBF) core for small size (150MWth) small modular reactor (SMR) was investigated. The purpose of this study was to design a once through cycle SMR core, where it can be used to supply electricity to a remote isolated area. PWR fuel assembly design with 17×17 arrangement, with 264 fuel rods per assembly was adopted as the basis design. The computer code CASMO-3/MASTER was used for the search of SBF core and fuel assembly analysis for SMR design. A low critical boron concentration (CBC) below 200 ppm core with 4.7 years once through cycle length was achieved using 57 fuel assemblies having 170 cm of active height. Core reactivity controlled using mainly 512 number of 4 wt% and 960 12 wt% Gd rods.

  14. Feasibility study on nuclear core design for soluble boron free small modular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rabir, Mohamad Hairie, E-mail: m-hairie@nuclearmalaysia.gov.my; Hah, Chang Joo; Ju, Cho Sung [Department of NPP Engineering, KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2015-04-29

    A feasibility study on nuclear core design of soluble boron free (SBF) core for small size (150MWth) small modular reactor (SMR) was investigated. The purpose of this study was to design a once through cycle SMR core, where it can be used to supply electricity to a remote isolated area. PWR fuel assembly design with 17×17 arrangement, with 264 fuel rods per assembly was adopted as the basis design. The computer code CASMO-3/MASTER was used for the search of SBF core and fuel assembly analysis for SMR design. A low critical boron concentration (CBC) below 200 ppm core with 4.7 years once through cycle length was achieved using 57 fuel assemblies having 170 cm of active height. Core reactivity controlled using mainly 512 number of 4 wt% and 960 12 wt% Gd rods.

  15. Real-time wavelet detection of crashes in limit cycles of non-stationary fusion plasmas

    NARCIS (Netherlands)

    van Berkel, M.; Witvoet, G.; M.R. de Baar,; Nuij, Pwjm; Morschec, H. G. ter; Steinbuch, M.

    2011-01-01

    The high performance mode (H-mode) is one of the baseline plasma scenarios for the experimental fusion reactor ITER. This scenario features a periodic crash-like reorganization of the plasma pressure and the magnetic flux in the plasma core and plasma periphery. The core instability is often referre

  16. Conceptual study of advanced PWR core design. Development of advanced PWR core neutronics analysis system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Hyo; Kim, Seung Cho; Kim, Taek Kyum; Cho, Jin Young; Lee, Hyun Cheol; Lee, Jung Hun; Jung, Gu Young [Seoul National University, Seoul (Korea, Republic of)

    1995-08-01

    The neutronics design system of the advanced PWR consists of (i) hexagonal cell and fuel assembly code for generation of homogenized few-group cross sections and (ii) global core neutronics analysis code for computations of steady-state pin-wise or assembly-wise core power distribution, core reactivity with fuel burnup, control rod worth and reactivity coefficients, transient core power, etc.. The major research target of the first year is to establish the numerical method and solution of multi-group diffusion equations for neutronics code development. Specifically, the following studies are planned; (i) Formulation of various numerical methods such as finite element method(FEM), analytical nodal method(ANM), analytic function expansion nodal(AFEN) method, polynomial expansion nodal(PEN) method that can be applicable for the hexagonal core geometry. (ii) Comparative evaluation of the numerical effectiveness of these methods based on numerical solutions to various hexagonal core neutronics benchmark problems. Results are follows: (i) Formulation of numerical solutions to multi-group diffusion equations based on numerical methods. (ii) Numerical computations by above methods for the hexagonal neutronics benchmark problems such as -VVER-1000 Problem Without Reflector -VVER-440 Problem I With Reflector -Modified IAEA PWR Problem Without Reflector -Modified IAEA PWR Problem With Reflector -ANL Large Heavy Water Reactor Problem -Small HTGR Problem -VVER-440 Problem II With Reactor (iii) Comparative evaluation on the numerical effectiveness of various numerical methods. (iv) Development of HEXFEM code, a multi-dimensional hexagonal core neutronics analysis code based on FEM. In the target year of this research, the spatial neutronics analysis code for hexagonal core geometry(called NEMSNAP-H temporarily) will be completed. Combination of NEMSNAP-H with hexagonal cell and assembly code will then equip us with hexagonal core neutronics design system. (Abstract Truncated)

  17. Composite fan stator assembly

    Energy Technology Data Exchange (ETDEWEB)

    Donges, G.L.

    1993-07-13

    A composite fan stator assembly is described for a gas turbine engine having at least two fan rotor stages, the composite stator assembly comprising: an annular composite fan case assembly including an access port, the fan case assembly circumferentially disposed around first and second fan rotor stage locations, a composite fan stator stage supported by and extending radially inward of the fan case assembly and axially disposed between the two fan rotor stage locations, the fan stator stage includes at least one removable vane segment accessible for removal through the access port for assembly and reassembly, the composite fan case assembly including a separable composite forward fan case assembly and a separable composite aft fan case assembly spaced axially aft of the forward fan case assembly, the forward fan case assembly being bolted to the aft fan case assembly, wherein the composite fan stator stage is axially and radially trapped and supported by the forward and aft fan case assemblies. A composite stator vane assembly comprising: a composite inner shroud, a composite outer shroud disposed radially outward of the inner shroud, a plurality of vanes disposed between the shrouds, the vanes including a suction side and a pressure side and radially inner and outer roots, the roots extending through platforms of corresponding ones of the inner and outer shrouds, four box-type attachment elements corresponding to curved suction and pressure sides of the inner and outer roots, the box-type attachment elements having two connected legs angled with respect to each other, a first one of the legs extending along, conforming to the curve of, and bonded to a corresponding one of the airfoil root sides, and a second one of the legs extending along and bonded to a composite shroud surface.

  18. Atomic and molecular processes in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Janev, R.K. [International Atomic Energy Agency, Vienna (Austria)

    1997-01-01

    The role of atomic and molecular processes in achieving and maintaining the conditions for thermonuclear burn in a magnetically confined fusion plasma is described. Emphasis is given to the energy balance and power and particle exhaust issues. The most important atomic and molecular processes which affect the radiation losses and impurity transport in the core plasma, the neutral particle transport in the plasma edge and the radiative cooling of divertor plasmas are discussed in greater detail. (author)

  19. Nuclear reactor core modelling in multifunctional simulators

    Energy Technology Data Exchange (ETDEWEB)

    Puska, E.K. [VTT Energy, Nuclear Energy, Espoo (Finland)

    1999-06-01

    The thesis concentrates on the development of nuclear reactor core models for the APROS multifunctional simulation environment and the use of the core models in various kinds of applications. The work was started in 1986 as a part of the development of the entire APROS simulation system. The aim was to create core models that would serve in a reliable manner in an interactive, modular and multifunctional simulator/plant analyser environment. One-dimensional and three-dimensional core neutronics models have been developed. Both models have two energy groups and six delayed neutron groups. The three-dimensional finite difference type core model is able to describe both BWR- and PWR-type cores with quadratic fuel assemblies and VVER-type cores with hexagonal fuel assemblies. The one- and three-dimensional core neutronics models can be connected with the homogeneous, the five-equation or the six-equation thermal hydraulic models of APROS. The key feature of APROS is that the same physical models can be used in various applications. The nuclear reactor core models of APROS have been built in such a manner that the same models can be used in simulator and plant analyser applications, as well as in safety analysis. In the APROS environment the user can select the number of flow channels in the three-dimensional reactor core and either the homogeneous, the five- or the six-equation thermal hydraulic model for these channels. The thermal hydraulic model and the number of flow channels have a decisive effect on the calculation time of the three-dimensional core model and thus, at present, these particular selections make the major difference between a safety analysis core model and a training simulator core model. The emphasis on this thesis is on the three-dimensional core model and its capability to analyse symmetric and asymmetric events in the core. The factors affecting the calculation times of various three-dimensional BWR, PWR and WWER-type APROS core models have been

  20. Hinode, SDO AIA, and CoMP Observations of a Coronal Cavity with a Hot Core

    Science.gov (United States)

    Reeves, K.; Jibben, P.

    2014-12-01

    Coronal cavities are low emission regions often situated around quiescent prominences. Prominences may exist for days or months prior to eruption and the magnetic structure of the cavity during the quiescent period is important to understanding the pre-eruption phase. We describe observations of a coronal cavity with a hot core situated above a polar crown prominence. The cavity, visible on the southwest limb, was observed for a period of three hours as a Hinode Coordinated Observation (HOP 114). Using Hinode's X-ray Telescope (XRT) and EUV Imaging Spectrometer (EIS) we present the thermal emission properties and coronal velocity structures of the cavity. We find the core has hotter temperatures than the surrounding plasma and there is evidence of turbulent velocities within the cavity. We also investigate the interaction of the cavity with the prominence material using Solar Dynamic Observatory (SDO) Atmospheric Imaging Assembly (AIA) data and H-alpha data from Hinode's Solar Optical Telescope (SOT). We find evidence of hot plasma at the spine of the prominence reaching into the cavity. These observations suggest a cylindrical flux tube best represents the cavity structure. The magnetic structure of the cavity is further discussed using data from the Coronal Multichannel Polarimeter (CoMP). This work is supported by under contract SP02H1701R from Lockheed-Martin to SAO, contract NNM07AB07C from NASA to SAO and grant number NNX12AI30G from NASA to SAO.

  1. Plasma harmonics

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    Preface; Why plasma harmonics? A very brief introduction Early stage of plasma harmonic studies - hopes and frustrations New developments in plasma harmonics studies: first successes Improvements of plasma harmonics; Theoretical basics of plasma harmonics; Basics of HHG Harmonic generation in fullerenes using few-cycle pulsesVarious approaches for description of observed peculiarities of resonant enhancement of a single harmonic in laser plasmaTwo-colour pump resonance-induced enhancement of odd and even harmonics from a tin plasmaCalculations of single harmonic generation from Mn plasma;Low-o

  2. Animal MRI Core

    Data.gov (United States)

    Federal Laboratory Consortium — The Animal Magnetic Resonance Imaging (MRI) Core develops and optimizes MRI methods for cardiovascular imaging of mice and rats. The Core provides imaging expertise,...

  3. Mechanical Design Concept of Fuel Assembly for Prototype GEN-IV Sodium-cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K. H.; Lee, C. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The prototype GEN-IV sodium-cooled fast reactor (PGSFR) is an advanced fast reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test for design certification at minimum cost and risk. The design concepts of the fuel assembly (FA) were introduced for a PGSFR. Unlike that for the pressurized water reactor, there is a neutron shielding concept in the FA and recycling metal fuel. The PGSFR core is a heterogeneous, uranium-10% zirconium (U-10Zr) metal alloy fuel design with 112 assemblies: 52 inner core fuel assemblies, 60 outer core fuel assemblies, 6 primary control assemblies, 3 secondary control assemblies, 90 reflector assemblies and 102 B4C shield assemblies. This configuration is shown in Fig. 1. The core is designed to produce 150 MWe with an average temperature rise of 155 .deg. C. The inlet temperature is 390 .deg. C and the bulk outlet temperature is 545 .deg. C. The core height is 900 mm and the gas plenum length is 1,250 mm. A mechanical design of a fuel assembly for a PGSFR was established. The mechanical design concepts are well realized in the design. In addition to this, the analytical and experimental works will be carries out for verifying the design soundness.

  4. The HOR HEU/LEU core conversion

    Energy Technology Data Exchange (ETDEWEB)

    Gibcus, H.P.M.; Vries, J.W. de [Department of HOR-Development, IRI, Delft University of Technology, Delft (Netherlands); Leege, P.F.A. de [Department of Reactor Physics, IRI, Delft University of Technology, Delft (Netherlands)

    1999-07-01

    On March 16, 1998 the first two LEU (low enriched uranium) fuel elements were introduced in the HOR reactor of the Interfaculty Reactor Institute (IRI). At the moment the core consists of 5 LEU and 19 HEU (highly enriched uranium) fuel elements. It is anticipated that after about 13 core reload operations the HOR will be fully converted from HEU to LEU to a so called LEU compact core consisting of about 21 LEU fuel assemblies and as many beryllium reflector elements. The HOR HEU/LEU core conversion program, progress of the step-by-step transition phase, including comparisons of calculations and measurements, as well as the impact on the utilization of the reactor are discussed. (author)

  5. Glomerular Filtration Barrier Assembly: An insight

    OpenAIRE

    Arif, Ehtesham; Nihalani, Deepak

    2013-01-01

    A glomerulus is the network of capillaries that resides in the Bowman’s capsule that functions as a filtration unit of kidney. The glomerular function ensures that essential plasma proteins are retained in blood and the filtrate is passed on as urine. The glomerular filtration assembly is composed of three main cellular barriers that are critical for the ultrafiltration process, the fenestrated endothelium, glomerular basement membrane and highly specialized podocytes. The podocytes along wit...

  6. Investigation of functionalized silicon nanowires by self-assembled monolayer

    Science.gov (United States)

    Hemed, Nofar Mintz; Convertino, Annalisa; Shacham-Diamand, Yosi

    2016-03-01

    The functionalization using self assembled monolayer (SAM) of silicon nanowires (SiNW) fabricated by plasma enhanced chemical vapor deposition (PECVD) is reported here. The SAM is being utilized as the first building block in the functionalization process. The morphology of the SiNW comprises a polycrystalline core wrapped by an hydrogenated amorphous silicon (α-Si:H) shell. Since most of the available methods for SAM verification and characterization are suitable only for flat substrates; therefore, in addition to the SiNW α-Si:H on flat samples were produced in the same system as the SiNWs. First we confirmed the SAM's presence on the flat α-Si:H samples using the following methods: contact angle measurement to determine the change in surface energy; atomic force microscopy (AFM) to determine uniformity and molecular coverage. Spectroscopic ellipsometry and X-ray reflectivity (XRR) were performed to measure SAM layer thickness and density. X-ray photoelectron spectroscopy (XPS) was applied to study the chemical states of the surface. Next, SiNW/SAM were tested by electrochemical impedance spectroscopy (EIS), and the results were compared to α-Si:H/SAM. The SAM electrical coverage on SiNW and α-Si:H was found to be ∼37% and ∼65 ± 3%, respectively. A model, based on transmission line theory for the nanowires is presented to explain the disparity in results between the nanowires and flat surface of the same materials.

  7. Preparation and in Vitro Release of Self-Assembled Neurotoxin-Loaded Nanoparticles of Core-Shell Type%神经毒素自组装核壳型纳米粒的制备及其体外释药研究

    Institute of Scientific and Technical Information of China (English)

    柳琳; 徐陆忠; 何晓玮; 赵燕敏; 冯健; 李范珠

    2009-01-01

    目的 制备亲水性多肽类药物神经毒素的自组装核壳型纳米粒,并对其理化性质及体外释药特性进行考察.方法 以聚乙二醇一聚氰基丙烯酸乙酯嵌段共聚物(PEG-g-PECA)为载体,乳化聚合法制备神经毒素自组装核壳型纳米粒,采用正交实验优化制备工艺,制得的核壳型纳米粒通过透射电镜、Zeta电位/粒度分布仪考察理化性质,并用透析袋法分别研究其在pH 7.4和6.8的PBS缓冲液中的体外释药特性.结果 PEG-g-PECA能包埋亲水性多肽神经毒素,制备的神经毒素自组装核壳型纳米粒粒径为(89.6±8.9)mm,多分散系数为(0.110±0.003),包封率为(58.43±0.62)%,Zeta电位为(-38.81±0.47)mV;在pH 7.4和6.8的PBS缓冲液中的体外释药行为均符合Weibull方程,分别为lnln[1/(1-Q)]=0.474Int-1.612 1,r=0.994 6(pH 7.4)及lnln[1/(1-Q)]=0.351Int-0.827 1,r=0.970 8(pH 6.8).结论 以PEG-g-PECA为载体制备亲水性多肽类药物自组装核壳型纳米粒方法可行,所得纳米粒包封率较高,理化性质稳定,体外释药具有缓释制剂特征.%OBJECTIVE To prepare the self-assembled neurotoxin-loaded nanoparticles of core-shell type, and investigate its physicochemical properties and release behavior in vitro. METHODS The self-assembled neurotoxin-loaded nanoparticles of core-shell type were prepared with PEG-g-PECA by emulsion polymerization method. The orthogonal design was used to optimize the preparation technology. The transmission electron microscope(TEM) and Zeta sizer instrument were utilized to investigate the physicochemical properties of the nanoparticles, and the drug release behavior in PBS buffer at pH 7.4 and 6.8 in vitro were studied by dialysis method respectively. RESULTS The mean diameter of the nanoparticles were (89.6±8.9)nm with polydispersity index of (0.110±0.003). The entrapment efficiency was (58.43±0.62)%, and Zeta potential was (-38.81±0.47) inV. The in vitro release profiles of the nanoparticles in pH 7

  8. ex vivo DNA assembly

    Directory of Open Access Journals (Sweden)

    Adam B Fisher

    2013-10-01

    Full Text Available Even with decreasing DNA synthesis costs there remains a need for inexpensive, rapid and reliable methods for assembling synthetic DNA into larger constructs or combinatorial libraries. Advances in cloning techniques have resulted in powerful in vitro and in vivo assembly of DNA. However, monetary and time costs have limited these approaches. Here, we report an ex vivo DNA assembly method that uses cellular lysates derived from a commonly used laboratory strain of Escherichia coli for joining double-stranded DNA with short end homologies embedded within inexpensive primers. This method concurrently shortens the time and decreases costs associated with current DNA assembly methods.

  9. Composite turbine bucket assembly

    Energy Technology Data Exchange (ETDEWEB)

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

  10. Target Assembly Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Target Assembly Facility integrates new armor concepts into actual armored vehicles. Featuring the capability ofmachining and cutting radioactive materials, it...

  11. Dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fortov, Vladimir E; Khrapak, Aleksei G; Molotkov, Vladimir I; Petrov, Oleg F [Institute for High Energy Densities, Associated Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation); Khrapak, Sergei A [Max-Planck-Institut fur Extraterrestrische Physik, Garching (Germany)

    2004-05-31

    The properties of dusty plasmas - low-temperature plasmas containing charged macroparticles - are considered. The most important elementary processes in dusty plasmas and the forces acting on dust particles are investigated. The results of experimental and theoretical investigations of different states of strongly nonideal dusty plasmas - crystal-like, liquid-like, gas-like - are summarized. Waves and oscillations in dusty plasmas, as well as their damping and instability mechanisms, are studied. Some results on dusty plasma investigated under microgravity conditions are presented. New directions of experimental research and potential applications of dusty plasmas are discussed. (reviews of topical problems)

  12. Core design and optimization of high performance low sodium void 1000 MWe heterogeneous oxide LMFBR cores

    Energy Technology Data Exchange (ETDEWEB)

    Barthold, W.P.; Orechwa, Y.; Su, S.F.; Beitel, J.C.; Turski, R.; Lam, P.S.K.; Fuller, E.L.

    1979-01-01

    Radially heterogeneous core configurations are effective means to reduce sodium void reactivity. In general, radially heterogeneous cores can be designed as tightly or loosely coupled cores with center core or center blanket arrangements. Core height, number of core regions and number of fuel pins per assembly are additional variables in an optimization of basic heterogeneous core configurations. An extensive study was carried out to optimize the core configurations for 1000 MWe LMFBRs. All cores were subject to a common set of nuclear, mechanical, and thermal-hydraulic design assumptions. They were restrained by an upper sodium void reactivity limit of $2.50 and a doubling time of approximately 15 to 18 years. The screening and optimization procedures employed lead to two core layouts which were both tightly coupled. A complete nuclear analysis of these two cores (derived from a loosely coupled configuration/derived from a tightly coupled configuration) determined the fissile inventories (4268.4/4213.4 kg at BOEC), burnups (83.90/100.7 MWd/t peak), reactivity swings (0.49/1.8% ..delta..k total), power and flux distributions for different control insertion patterns, the breeding performance (15.7/15.3 yrs CSDT), the safety parameters, such as sodium void reactivity ($2.38/$2.23 at EOEC), isothermal Doppler coefficients for both sodium-in (45.6/46.1 T dk/dT x 10/sup -4/ core at EOEC) and sodium-out conditions (28.6/28.2 T dk/dT x 10/sup -4/ core at EOEC), and the transient behavior which shows very little space-dependence during a 60 cent reactivity step insertion.

  13. Rhapsody-G simulations I: the cool cores, hot gas and stellar content of massive galaxy clusters

    CERN Document Server

    Hahn, Oliver; Wu, Hao-Yi; Evrard, August E; Teyssier, Romain; Wechsler, Risa H

    2015-01-01

    We present the Rhapsody-G suite of cosmological hydrodynamic AMR zoom simulations of ten massive galaxy clusters at the $M_{\\rm vir}\\sim10^{15}\\,{\\rm M}_\\odot$ scale. These simulations include cooling and sub-resolution models for star formation and stellar and supermassive black hole feedback. The sample is selected to capture the whole gamut of assembly histories that produce clusters of similar final mass. We present an overview of the successes and shortcomings of such simulations in reproducing both the stellar properties of galaxies as well as properties of the hot plasma in clusters. In our simulations, a long-lived cool-core/non-cool core dichotomy arises naturally, and the emergence of non-cool cores is related to low angular momentum major mergers. Nevertheless, the cool-core clusters exhibit a low central entropy compared to observations, which cannot be alleviated by thermal AGN feedback. For cluster scaling relations we find that the simulations match well the $M_{500}-Y_{500}$ scaling of Planck ...

  14. Evaluation of nuclear characteristics of DCA modification core for sub-critical measurement

    Energy Technology Data Exchange (ETDEWEB)

    Hazama, Taira [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-10-01

    Critical experiments were carried out on Deuterium Critical Assembly (DCA) modification core. DCA modification core has two regions, that is, test region and driver region. The test region consists of various types of fuel and moderator, while the driver region remains the same as the original DCA core (ATR simulated core). Critical characteristics were measured with various types of core patterns and were compared with calculated values based on SCALE code system. Monte Calro code KENO was found to be very accurate in the core analysis. The accuracy stays below 0.5 %dk/k in keff even if core configuration is extremely complicated. (author)

  15. Controlling plasmon coupling in biomolecule-linked metal nanoparticle assemblies

    Science.gov (United States)

    Sebba, David S.

    Molecular control of plasmon coupling is investigated in biomolecule-linked nanoparticle assemblies in two-particle, small cluster, and extended network formats. The relationship between structure and optical properties is explored through comparison of measured spectra with simulated spectra calculated using structural models based upon measured structural parameters. A variety of techniques are used to characterize nanoparticle assemblies, including ensemble extinction and elastic scattering spectroscopy, single-assembly scattering spectroscopy, transmission electron microscopy, and dynamic light scattering. Initially, molecular control of plasmon coupling is investigated in ˜100 nm assemblies composed of 13 nm gold "satellite" particles tethered by duplex DNA to a 50 nm gold "core" particle. Comparison of core-satellite assemblies formed with duplex DNA tethers of varying length demonstrates that, while core-satellite separation is controlled by the number of base pairs in the DNA tether, structural properties such as core:satellite ratio and yield are independent of DNA tether length. Thus, plasmon coupling within these assemblies is determined by the number of base pairs in the duplex DNA tether; compact assemblies in which tethers are composed of fewer base pairs exhibit plasmon bands that are red-shifted relative to the bands of extended assemblies, indicating increased plasmon coupling in the compact assemblies. Subsequently, core-satellite assemblies are formed with reconfigurable DNA nanostructure tethers that modulate interparticle separation in response to a molecular stimulus. Assembly reconfiguration from a compact to an extended state results in blue-shifting of the assembly plasmon resonance, indicating reduced interparticle coupling and lengthening of the core-satellite tether. Comparison between measured and simulated spectra revealed a close correspondence and provided validation of the structural models that link assembly plasmonic properties

  16. Reactivity control assembly for nuclear reactor. [LMFBR

    Science.gov (United States)

    Bollinger, L.R.

    1982-03-17

    This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.

  17. Contact activation of blood-plasma coagulation

    Science.gov (United States)

    Golas, Avantika

    Surface engineering of biomaterials with improved hemocompatibility is an imperative, given the widespread global need for cardiovascular devices. Research summarized in this dissertation focuses on contact activation of FXII in buffer and blood plasma frequently referred to as autoactivation. The extant theory of contact activation imparts FXII autoactivation ability to negatively charged, hydrophilic surfaces. According to this theory, contact activation of plasma involves assembly of proteins comprising an "activation complex" on activating surfaces mediated by specific chemical interactions between complex proteins and the surface. This work has made key discoveries that significantly improve our core understanding of contact activation and unravel the existing paradigm of plasma coagulation. It is shown herein that contact activation of blood factor XII (FXII, Hageman factor) in neat-buffer solution exhibits a parabolic profile when scaled as a function of silanized-glass-particle activator surface energy (measured as advancing water adhesion tension t°a=g° Iv costheta in dyne/cm, where g°Iv is water interfacial tension in dyne/cm and theta is the advancing contact angle). Nearly equal activation is observed at the extremes of activator water-wetting properties --36 < t°a < 72 dyne/cm (O° ≤ theta < 120°), falling sharply through a broad minimum within the 20 < t°a < 40 dyne/cm (55° < theta < 75°). Furthermore, contact activation of FXII in buffer solution produces an ensemble of protein fragments exhibiting either procoagulant properties in plasma (proteolysis of blood factor XI or prekallikrein), amidolytic properties (cleavage of s-2302 chromogen), or the ability to suppress autoactivation through currently unknown biochemistry. The relative proportions of these fragments depend on activator surface chemistry/energy. We have also discovered that contact activation is moderated by adsorption of plasma proteins unrelated to coagulation through an

  18. Extending reference assembly models

    DEFF Research Database (Denmark)

    Church, Deanna M.; Schneider, Valerie A.; Steinberg, Karyn Meltz

    2015-01-01

    The human genome reference assembly is crucial for aligning and analyzing sequence data, and for genome annotation, among other roles. However, the models and analysis assumptions that underlie the current assembly need revising to fully represent human sequence diversity. Improved analysis tools...

  19. Assembly of primary cilia

    DEFF Research Database (Denmark)

    Pedersen, Lotte B; Veland, Iben R; Schrøder, Jacob M

    2008-01-01

    in primary cilia assembly or function have been associated with a panoply of disorders and diseases, including polycystic kidney disease, left-right asymmetry defects, hydrocephalus, and Bardet Biedl Syndrome. Here we provide an up-to-date review focused on the molecular mechanisms involved in the assembly...

  20. Extending reference assembly models

    DEFF Research Database (Denmark)

    Church, Deanna M.; Schneider, Valerie A.; Steinberg, Karyn Meltz;

    2015-01-01

    The human genome reference assembly is crucial for aligning and analyzing sequence data, and for genome annotation, among other roles. However, the models and analysis assumptions that underlie the current assembly need revising to fully represent human sequence diversity. Improved analysis tools...

  1. Perspective: Geometrically frustrated assemblies

    Science.gov (United States)

    Grason, Gregory M.

    2016-09-01

    This perspective will overview an emerging paradigm for self-organized soft materials, geometrically frustrated assemblies, where interactions between self-assembling elements (e.g., particles, macromolecules, proteins) favor local packing motifs that are incompatible with uniform global order in the assembly. This classification applies to a broad range of material assemblies including self-twisting protein filament bundles, amyloid fibers, chiral smectics and membranes, particle-coated droplets, curved protein shells, and phase-separated lipid vesicles. In assemblies, geometric frustration leads to a host of anomalous structural and thermodynamic properties, including heterogeneous and internally stressed equilibrium structures, self-limiting assembly, and topological defects in the equilibrium assembly structures. The purpose of this perspective is to (1) highlight the unifying principles and consequences of geometric frustration in soft matter assemblies; (2) classify the known distinct modes of frustration and review corresponding experimental examples; and (3) describe outstanding questions not yet addressed about the unique properties and behaviors of this broad class of systems.

  2. Laser bottom hole assembly

    Science.gov (United States)

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  3. Chalcogenide glass hollow core microstructured optical fibers

    Science.gov (United States)

    Shiryaev, Vladimir S.

    2015-03-01

    The recent developments on chalcogenide glass hollow core microstructured optical fibers (HC-MOFs) are presented. The comparative analysis of simulated optical properties for chalcogenide HC-MOFs of negative-curvature with different size and number of capillaries is given. The technique for the manufacture of microstructured chalcogenide preforms, which includes the assembly of the substrate glass tube and 8-10 capillaries, is described. Further trends to improve the optical transmission in chalcogenide NCHCFs are considered.

  4. Assembly: a resource for assembled genomes at NCBI.

    Science.gov (United States)

    Kitts, Paul A; Church, Deanna M; Thibaud-Nissen, Françoise; Choi, Jinna; Hem, Vichet; Sapojnikov, Victor; Smith, Robert G; Tatusova, Tatiana; Xiang, Charlie; Zherikov, Andrey; DiCuccio, Michael; Murphy, Terence D; Pruitt, Kim D; Kimchi, Avi

    2016-01-04

    The NCBI Assembly database (www.ncbi.nlm.nih.gov/assembly/) provides stable accessioning and data tracking for genome assembly data. The model underlying the database can accommodate a range of assembly structures, including sets of unordered contig or scaffold sequences, bacterial genomes consisting of a single complete chromosome, or complex structures such as a human genome with modeled allelic variation. The database provides an assembly accession and version to unambiguously identify the set of sequences that make up a particular version of an assembly, and tracks changes to updated genome assemblies. The Assembly database reports metadata such as assembly names, simple statistical reports of the assembly (number of contigs and scaffolds, contiguity metrics such as contig N50, total sequence length and total gap length) as well as the assembly update history. The Assembly database also tracks the relationship between an assembly submitted to the International Nucleotide Sequence Database Consortium (INSDC) and the assembly represented in the NCBI RefSeq project. Users can find assemblies of interest by querying the Assembly Resource directly or by browsing available assemblies for a particular organism. Links in the Assembly Resource allow users to easily download sequence and annotations for current versions of genome assemblies from the NCBI genomes FTP site.

  5. Self-assembled nanostructures

    CERN Document Server

    Zhang, Jin Z; Liu, Jun; Chen, Shaowei; Liu, Gang-yu

    2003-01-01

    Nanostructures refer to materials that have relevant dimensions on the nanometer length scales and reside in the mesoscopic regime between isolated atoms and molecules in bulk matter. These materials have unique physical properties that are distinctly different from bulk materials. Self-Assembled Nanostructures provides systematic coverage of basic nanomaterials science including materials assembly and synthesis, characterization, and application. Suitable for both beginners and experts, it balances the chemistry aspects of nanomaterials with physical principles. It also highlights nanomaterial-based architectures including assembled or self-assembled systems. Filled with in-depth discussion of important applications of nano-architectures as well as potential applications ranging from physical to chemical and biological systems, Self-Assembled Nanostructures is the essential reference or text for scientists involved with nanostructures.

  6. Constrained space camera assembly

    Science.gov (United States)

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  7. Construction of linear empirical core models for pressurized water reactor in-core fuel management

    Energy Technology Data Exchange (ETDEWEB)

    Okafor, K.C.; Aldemir, T. (The Ohio State Univ., Dept. of Mechanical Engineering, Nuclear Engineering Program, 206 West 18th Ave., Columbus, OH (US))

    1988-06-01

    An empirical core model construction procedure for pressurized water reactor (PWR) in-core fuel management problems is presented that (a) incorporates the effect of composition changes in all the control zones in the core of a given fuel assembly, (b) is valid at all times during the cycle for a given range of control variables, (c) allows determining the optimal beginning of cycle (BOC) kappainfinity distribution as a single linear programming problem,and (d) provides flexibility in the choice of the material zones to describe core composition. Although the modeling procedure assumes zero BOC burnup, the predicted optimal kappainfinity profiles are also applicable to reload cores. In model construction, assembly power fractions and burnup increments during the cycle are regarded as the state (i.e., dependent) variables. Zone enrichments are the control (i.e., independent) variables. The model construction procedure is validated and implemented for the initial core of a PWR to determine the optimal BOC kappainfinity profiles for two three-zone scatter loading schemes. The predicted BOC kappainfinity profiles agree with the results of other investigators obtained by different modeling techniques.

  8. k-core covers and the core

    NARCIS (Netherlands)

    Sanchez-Rodriguez, E.; Borm, Peter; Estevez-Fernandez, A.; Fiestras-Janeiro, G.; Mosquera, M.A.

    2015-01-01

    This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

  9. Academic Rigor: The Core of the Core

    Science.gov (United States)

    Brunner, Judy

    2013-01-01

    Some educators see the Common Core State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common Core are not the only…

  10. k-core covers and the core

    NARCIS (Netherlands)

    Sanchez-Rodriguez, E.; Borm, Peter; Estevez-Fernandez, A.; Fiestras-Janeiro, G.; Mosquera, M.A.

    This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

  11. Performance and properties of the first plasmas of Wendelstein 7-X

    Science.gov (United States)

    Klinger, T.; Alonso, A.; Bozhenkov, S.; Burhenn, R.; Dinklage, A.; Fuchert, G.; Geiger, J.; Grulke, O.; Langenberg, A.; Hirsch, M.; Kocsis, G.; Knauer, J.; Krämer-Flecken, A.; Laqua, H.; Lazerson, S.; Landreman, M.; Maaßberg, H.; Marsen, S.; Otte, M.; Pablant, N.; Pasch, E.; Rahbarnia, K.; Stange, T.; Szepesi, T.; Thomsen, H.; Traverso, P.; Velasco, J. L.; Wauters, T.; Weir, G.; Windisch, T.; The Wendelstein 7-X Team

    2017-01-01

    The optimized, superconducting stellarator Wendelstein 7-X went into operation and delivered first measurement data after 15 years of construction and one year commissioning. Errors in the magnet assembly were confirmend to be small. Plasma operation was started with 5 MW electron cyclotron resonance heating (ECRH) power and five inboard limiters. Core plasma values of {{T}\\text{e}}>8 keV, {{T}\\text{i}}>2 keV at line-integrated densities n≈ 3\\centerdot {{10}19}~{{\\text{m}}-2} were achieved, exceeding the original expectations by about a factor of two. Indications for a core-electron-root were found. The energy confinement times are in line with the international stellarator scaling, despite unfavourable wall conditions, i.e. large areas of metal surfaces and particle sources from the limiter close to the plasma volume. Well controlled shorter hydrogen discharges at higher power (4 MW ECRH power for 1 s) and longer discharges at lower power (0.7 MW ECRH power for 6 s) could be routinely established after proper wall conditioning. The fairly large set of diagnostic systems running in the end of the 10 weeks operation campaign provided first insights into expected and unexpected physics of optimized stellarators.

  12. Plasma Simulation Program

    Energy Technology Data Exchange (ETDEWEB)

    Greenwald, Martin

    2011-10-04

    Many others in the fusion energy and advanced scientific computing communities participated in the development of this plan. The core planning team is grateful for their important contributions. This summary is meant as a quick overview the Fusion Simulation Program's (FSP's) purpose and intentions. There are several additional documents referenced within this one and all are supplemental or flow down from this Program Plan. The overall science goal of the DOE Office of Fusion Energy Sciences (FES) Fusion Simulation Program (FSP) is to develop predictive simulation capability for magnetically confined fusion plasmas at an unprecedented level of integration and fidelity. This will directly support and enable effective U.S. participation in International Thermonuclear Experimental Reactor (ITER) research and the overall mission of delivering practical fusion energy. The FSP will address a rich set of scientific issues together with experimental programs, producing validated integrated physics results. This is very well aligned with the mission of the ITER Organization to coordinate with its members the integrated modeling and control of fusion plasmas, including benchmarking and validation activities. [1]. Initial FSP research will focus on two critical Integrated Science Application (ISA) areas: ISA1, the plasma edge; and ISA2, whole device modeling (WDM) including disruption avoidance. The first of these problems involves the narrow plasma boundary layer and its complex interactions with the plasma core and the surrounding material wall. The second requires development of a computationally tractable, but comprehensive model that describes all equilibrium and dynamic processes at a sufficient level of detail to provide useful prediction of the temporal evolution of fusion plasma experiments. The initial driver for the whole device model will be prediction and avoidance of discharge-terminating disruptions, especially at high performance, which are a

  13. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  14. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  15. Mirror-field confined compact plasma source using permanent magnet for plasma processings

    Science.gov (United States)

    Goto, Tetsuya; Sato, Kei-ichiro; Yabuta, Yuki; Sugawa, Shigetoshi

    2016-12-01

    A mirror-field confined compact electron cyclotron resonance (ECR) plasma source using permanent magnets was developed, aiming for the realization of high-quality plasma processings where high-density reactive species are supplied to a substrate with minimizing the ion bombardment damages. The ECR position was located between a microwave transmissive window and a quartz limiter, and plasmas were transported from the ECR position to a midplane of the magnetic mirror field through the quartz limiter. Thus, a radius of core plasma could be determined by the limiter, which was 15 mm in this study. Plasma parameters were investigated by the Langmuir probe measurement. High-density plasma larger than 1011 cm-3 could be produced by applying 5.85-GHz microwave power of 10 W or more. For the outside region of the core plasma where a wafer for plasma processings will be set at, the ion current density was decreased dramatically with distance from the core plasma and became smaller by approximately two orders of magnitude that in the core plasma region for the radial position of 40 mm, suggesting the realization of reduction in ion bombardment damages.

  16. Mirror-field confined compact plasma source using permanent magnet for plasma processings.

    Science.gov (United States)

    Goto, Tetsuya; Sato, Kei-Ichiro; Yabuta, Yuki; Sugawa, Shigetoshi

    2016-12-01

    A mirror-field confined compact electron cyclotron resonance (ECR) plasma source using permanent magnets was developed, aiming for the realization of high-quality plasma processings where high-density reactive species are supplied to a substrate with minimizing the ion bombardment damages. The ECR position was located between a microwave transmissive window and a quartz limiter, and plasmas were transported from the ECR position to a midplane of the magnetic mirror field through the quartz limiter. Thus, a radius of core plasma could be determined by the limiter, which was 15 mm in this study. Plasma parameters were investigated by the Langmuir probe measurement. High-density plasma larger than 10(11) cm(-3) could be produced by applying 5.85-GHz microwave power of 10 W or more. For the outside region of the core plasma where a wafer for plasma processings will be set at, the ion current density was decreased dramatically with distance from the core plasma and became smaller by approximately two orders of magnitude that in the core plasma region for the radial position of 40 mm, suggesting the realization of reduction in ion bombardment damages.

  17. Dynamic nanoparticle assemblies.

    Science.gov (United States)

    Wang, Libing; Xu, Liguang; Kuang, Hua; Xu, Chuanlai; Kotov, Nicholas A

    2012-11-20

    Although nanoparticle (NP) assemblies are at the beginning of their development, their unique geometrical shapes and media-responsive optical, electronic, and magnetic properties have attracted significant interest. Nanoscale assembly bridges multiple levels of hierarchy of materials: individual nanoparticles, discrete molecule-like or virus-like nanoscale agglomerates, microscale devices, and macroscale materials. The capacity to self-assemble can greatly facilitate the integration of nanotechnology with other technologies and, in particular, with microscale fabrication. In this Account, we describe developments in the emerging field of dynamic NP assemblies, which are spontaneously form superstructures containing more than two inorganic nanoscale particles that display the ability to change their geometrical, physical, chemical, and other attributes. In many ways, dynamic assemblies can represent a bottleneck in the "bottom-up" fabrication of NP-based devices because they can produce a much greater variety of assemblies, but they also provide a convenient tool for variation of geometries and dimensions of nanoparticle assemblies. Superstructures of NPs (and those held together by similar intrinsic forces)are classified into two groups: Class 1 where media and external fields can alter shape, conformation, and order of stable super structures with a nearly constant number of NPs or Class 2 where the total number of NPs changes, while the organizational motif in the final superstructure remains the same. The future development of successful dynamic assemblies requires understanding the equilibrium in dynamic NP systems. The dynamic nature of Class 1 assemblies is associated with the equilibrium between different conformations of a superstructure and is comparable to the isomerization in classical chemistry. Class 2 assemblies involve the formation or breakage of linkages between the NPs, which is analogous to the classical chemical equilibrium for the formation of

  18. Most advanced HTP fuel assembly design for EPR

    Energy Technology Data Exchange (ETDEWEB)

    Francillon, Eric [AREVA - Framatome ANP, 10 rue Juliette Recamier - 69456 Lyon Cedex 06 (France); Kiehlmann, Horst-Dieter [AREVA - Framatome ANP GmbH, P.O. Box 3220, 91050 Erlangen (Germany)

    2006-07-01

    End 2003, the Finnish electricity utility Teollisuuden Voima Oy (TVO) signed the contract for building an EPR in Olkiluoto (Finland). Mid 2004, the French electricity utility EDF selected an EPR to be built in France. In 2005, Framatome ANP, an AREVA and Siemens company, announced that they will be pursuing a design certification in the U.S. The EPR development is based on the latest PWR product lines of former Framatome (N4) and Siemens Nuklear (Konvoi). As an introductory part, different aspects of the EPR core characteristics connected to fuel assembly design are presented. It includes means of ensuring reactivity control like hybrid AIC/B4C control rod absorbers and gadolinium as burnable absorber integrated in fuel rods, and specific options for in-core instrumentation, such as Aeroball type instrumentation. Then the design requirements for the EPR fuel assembly are presented in term of very high burnup capacity, rod cladding and fuel assembly reliability. Framatome ANP fuel assembly product characteristics meeting these requirements are then described. EPR fuel assembly design characteristics benefit from the experience feedback of the latest fuel assembly products designed within Framatome ANP, leading to resistance to assembly deformation, high fuel rod restraint and prevention of handling hazards. EPR fuel assembly design features the best components composing the cornerstones of the upgraded family of fuel assemblies that FRAMATOME ANP proposes today. This family is based on a set of common characteristics and associated features, which include the HMP grid as bottom end spacer, the MONOBLOC guide tube and the Robust FUELGUARD as lower tie plate, the use of the M5 Alloy, as cladding and structure material. This fully re-crystallized, ternary Zr-Nb-O alloy produces radically improved in-reactor corrosion, very low hydrogen uptake and growth and an excellent creep behavior, which are described there. EPR fuel assembly description also includes fuel rod

  19. DC source assemblies

    Science.gov (United States)

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  20. Modular assembled space telescope

    Science.gov (United States)

    Feinberg, Lee D.; Budinoff, Jason; MacEwen, Howard; Matthews, Gary; Postman, Marc

    2013-09-01

    We present a new approach to building a modular segmented space telescope that greatly leverages the heritage of the Hubble Space Telescope and the James Webb Space Telescope. The modular design in which mirror segments are assembled into identical panels allows for economies of scale and for efficient space assembly that make a 20-m aperture approach cost effective. This assembly approach can leverage NASA's future capabilities and has the power to excite the public's imagination. We discuss the science drivers, basic architecture, technology, and leveraged NASA infrastructure, concluding with a proposed plan for going forward.

  1. Comodules over semiperfect corings

    CERN Document Server

    Caenepeel, S

    2011-01-01

    We discuss when the Rat functor associated to a coring satisfying the left $\\alpha$-condition is exact. We study the category of comodules over a semiperfect coring. We characterize semiperfect corings over artinian rings and over qF-rings.

  2. Coring Sample Acquisition Tool

    Science.gov (United States)

    Haddad, Nicolas E.; Murray, Saben D.; Walkemeyer, Phillip E.; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Kriechbaum, Kristopher L.; Richardson, Megan; Klein, Kerry J.

    2012-01-01

    A sample acquisition tool (SAT) has been developed that can be used autonomously to sample drill and capture rock cores. The tool is designed to accommodate core transfer using a sample tube to the IMSAH (integrated Mars sample acquisition and handling) SHEC (sample handling, encapsulation, and containerization) without ever touching the pristine core sample in the transfer process.

  3. PlasmaPy: beginning a community developed Python package for plasma physics

    Science.gov (United States)

    Murphy, Nicholas A.; Huang, Yi-Min; PlasmaPy Collaboration

    2016-10-01

    In recent years, researchers in several disciplines have collaborated on community-developed open source Python packages such as Astropy, SunPy, and SpacePy. These packages provide core functionality, common frameworks for data analysis and visualization, and educational tools. We propose that our community begins the development of PlasmaPy: a new open source core Python package for plasma physics. PlasmaPy could include commonly used functions in plasma physics, easy-to-use plasma simulation codes, Grad-Shafranov solvers, eigenmode solvers, and tools to analyze both simulations and experiments. The development will include modern programming practices such as version control, embedding documentation in the code, unit tests, and avoiding premature optimization. We will describe early code development on PlasmaPy, and discuss plans moving forward. The success of PlasmaPy depends on active community involvement and a welcoming and inclusive environment, so anyone interested in joining this collaboration should contact the authors.

  4. Designing Assemblies Of Plates

    Science.gov (United States)

    Williams, F. W.; Kennedy, D.; Butler, R.; Aston, G.; Anderson, M. S.

    1992-01-01

    VICONOPT calculates vibrations and instabilities of assemblies of prismatic plates. Designed for efficient, accurate analysis of buckling and vibration, and for optimum design of panels of composite materials. Written in FORTRAN 77.

  5. Visualisation in Assembly

    Directory of Open Access Journals (Sweden)

    Václav Štefan

    2016-09-01

    Full Text Available The article is aimed at visualisation types in assembly. Broad usage of artificial visualisation in assembly is held down mainly for economic reasons. One of the possible solutions is usage of the presented light visualisation method. This simple method of light visualisation is convenient when vibration orientation is not working properly and artificial visualisation is economically ineffective. Described principle of orientation is a technical solution of the author.

  6. VIRUS instrument collimator assembly

    Science.gov (United States)

    Marshall, Jennifer L.; DePoy, Darren L.; Prochaska, Travis; Allen, Richard D.; Williams, Patrick; Rheault, Jean-Philippe; Li, Ting; Nagasawa, Daniel Q.; Akers, Christopher; Baker, David; Boster, Emily; Campbell, Caitlin; Cook, Erika; Elder, Alison; Gary, Alex; Glover, Joseph; James, Michael; Martin, Emily; Meador, Will; Mondrik, Nicholas; Rodriguez-Patino, Marisela; Villanueva, Steven; Hill, Gary J.; Tuttle, Sarah; Vattiat, Brian; Lee, Hanshin; Chonis, Taylor S.; Dalton, Gavin B.; Tacon, Mike

    2014-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

  7. Comparison of HCV core and coreE1E2 virus-like particles generated by stably transfected Leishmania tarentolae for stimulation of Th1 immune responses in mice.

    Science.gov (United States)

    Bolhassani, Azam; Davoudi, Noushin; Agi, Elnaz; Motevalli, Fatemeh

    2017-01-25

    Virus-like particles (VLPs) could be improved into successful immunogens as well as a potent delivery vehicle, but however, the current expression systems for VLPs production have some limitations. Recently, we developed a novel strategy to produce two HCV VLPs containing core or coreE1E2 proteins using stably transfected Leishmania tarentolae promastigotes. Then, BALB/c mice were injected by both viral like particles in different immunization strategies such as homologous DNA-, homologous VLP-, and heterologous DNA/ VLP-based immunizations. TEM microscopy indicated HCV core and HCV coreE1E2 VLP assembly with average size of 30-40 and 40-60 nm after purification, respectively. Our results showed that homologous immunizations with both HCV core or coreE1E2 VLPs significantly induced anti-core or anti-coreE1E2 antibody responses, respectively as well as secretion of IFN-γ cytokine as compared to other strategies. Moreover, DNA-prime/VLP-boost regimens significantly elicited higher levels of IFN-γ and antibody responses in comparison with homologous DNA/DNA regimens. The groups immunized with homologous or heterologous coreE1E2 VLPs showed markedly higher immune responses as compared to groups immunized with core VLP regimens against coreE1E2 protein. The crude HCV VLPs generated by Leishmania expression system could elicit a Th1-type response as a promising vaccine candidate against HCV infections.

  8. Polymer Directed Protein Assemblies

    Directory of Open Access Journals (Sweden)

    Patrick van Rijn

    2013-05-01

    Full Text Available Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e.g., virus particles. Viruses are a multi-protein assembly of which the morphology is dictated by poly-nucleotides namely RNA or DNA. This “biopolymer” directs the proteins and imposes limitations on the structure like the length or diameter of the particle. Not only do these bionanoparticles use polymer-directed self-assembly, also processes like amyloid formation are in a way a result of directed protein assembly by partial unfolded/misfolded biopolymers namely, polypeptides. The combination of proteins and synthetic polymers, inspired by the natural processes, are therefore regarded as a highly promising area of research. Directed protein assembly is versatile with respect to the possible interactions which brings together the protein and polymer, e.g., electrostatic, v.d. Waals forces or covalent conjugation, and possible combinations are numerous due to the large amounts of different polymers and proteins available. The protein-polymer interacting behavior and overall morphology is envisioned to aid in clarifying protein-protein interactions and are thought to entail some interesting new functions and properties which will ultimately lead to novel bio-hybrid materials.

  9. Banded transformer cores

    Science.gov (United States)

    Mclyman, C. W. T. (Inventor)

    1974-01-01

    A banded transformer core formed by positioning a pair of mated, similar core halves on a supporting pedestal. The core halves are encircled with a strap, selectively applying tension whereby a compressive force is applied to the core edge for reducing the innate air gap. A dc magnetic field is employed in supporting the core halves during initial phases of the banding operation, while an ac magnetic field subsequently is employed for detecting dimension changes occurring in the air gaps as tension is applied to the strap.

  10. Rapid rotational crust-core relaxation in magnetars

    CERN Document Server

    Sedrakian, Armen

    2016-01-01

    If a magnetar interior $B$-field exceeds $10^{15}$ G it will unpair the proton superconductor in the star's core by inducing diamagnetic currents which destroy the Cooper pair coherence. Then, the $P$-wave neutron superfluid in these non-superconducting regions will couple to the stellar plasma by scattering of protons off the quasiparticles confined in the cores of neutron vortices via the strong (nuclear) force. The dynamical time-scales associated with this interaction span from several minutes at the crust-core interface to a few seconds in the deep core. We show that (a) the rapid crust-core coupling is incompatible with oscillation models of magnetars which decouple completely the core superfluid from the crust and (b) magnetar precession is damped by the coupling of normal fluids to the superfluid core and, if observed, needs to be forced or continuously excited by seismic activity.

  11. Complex plasmas scientific challenges and technological opportunities

    CERN Document Server

    Lopez, Jose; Becker, Kurt; Thomsen, Hauke

    2014-01-01

    This book provides the reader with an introduction to the physics of complex plasmas, a discussion of the specific scientific and technical challenges they present, and an overview of their potential technological applications. Complex plasmas differ from conventional high-temperature plasmas in several ways: they may contain additional species, including nanometer- to micrometer-sized particles, negative ions, molecules and radicals, and they may exhibit strong correlations or quantum effects. This book introduces the classical and quantum mechanical approaches used to describe and simulate complex plasmas. It also covers some key experimental techniques used in the analysis of these plasmas, including calorimetric probe methods, IR absorption techniques and X-ray absorption spectroscopy. The final part of the book reviews the emerging applications of microcavity and microchannel plasmas, the synthesis and assembly of nanomaterials through plasma electrochemistry, the large-scale generation of ozone using mi...

  12. EDITORIAL: Plasma jets and plasma bullets Plasma jets and plasma bullets

    Science.gov (United States)

    Kong, M. G.; Ganguly, B. N.; Hicks, R. F.

    2012-06-01

    technological solution in the early to late 1990s of confining atmospheric plasmas in a small volume of plasma generation (i.e. with a small volume-to-surface ratio) and then extending it towards a downstream sample [7]-[9]. These are among the first low-temperature atmospheric plasmas aimed particularly at the exploitation of their ability to invoke the active and rich reactive chemistry close to ambient temperature. The main applications of these early devices are precision surface modification of low-temperature dielectric materials, for example thin film deposition and etching [7]-[9]. Variations of the early plasma jets include atmospheric plasma sheet jets [10] for the treatment of largely planar objects (e.g. polymeric sheets) as well as large arrays of many plasma jets for the treatment of complex-structured objects (e.g. surgical tools and open human wounds) [11]. As a material processing technology, the sub-100oC atmospheric-pressure plasma jet has benefited over the years from many innovations. Whilst a detailed account and analysis of these is clearly outside the scope of this Editorial, it is worth stating that there are different avenues with which to maintain a moderate electron density at the plasma core so as to keep the gas temperature at the sample point below a ceiling level. Most of the early studies employed excitation at radio frequencies above 10 MHz, at which electrons are largely confined in the plasma generation region, and this limits the current flow to and gas heating in the plume region of the plasma jet. Other techniques of current limitation have since been shown to be effective, including the use of dielectric barriers across a very large frequency range of 1 kHz--50 MHz, sub-microsecond pulses sustained at kHz frequencies, pulse-modulated radio frequencies and dual-frequency excitation [12]-[15]. These and other techniques have considerably advanced the atmospheric-pressure plasma jet technology. The period of some 15 years since the above

  13. LMFBR type reactor core and its fuel exchange method

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Yoko; Koyama, Jun-ichi; Aoyama, Motoo; Haikawa, Katsumasa; Yamanaka, Akihiro

    1996-08-20

    Upon initial loading, two kinds of fuel assemblies including first fuel assemblies having a highest enrichment degree and second fuel assemblies having a lowest enrichment degree are loaded. The average fuel enrichment degree of an upper region of the first fuel assembly is made greater than that of the lower region. The reactivity of the lower region of the first fuel assembly is made lower than that of the upper portion to reduce power peak. Upon transfer from a first cycle to a second cycle, at least one of the second fuel assemblies is exchanged by the same number of the third fuel assemblies. In this case, an average fuel enrichment degree of the upper region of the third fuel assembly is made greater than that of the lower region to suppress the reactivity in the lower region of the third fuel assembly lower than the reactivity in the upper region thereby reducing the power peak. Thus, the upper power peak over the entire reactor core is moderated thereby capable of ensuring the reactor shut down margin without deteriorating the same. (N.H.)

  14. Mechanisms of Centrosome Separation and Bipolar Spindle Assembly

    NARCIS (Netherlands)

    Tanenbaum, Marvin E.; Medema, Rene H.

    2010-01-01

    Accurate segregation of chromosomes during cell division is accomplished through the assembly of a bipolar microtubule-based structure called the mitotic spindle. Work over the past two decades has identified a core regulator of spindle bipolarity, the microtubule motor protein kinesin-5. However, a

  15. Modular container assembled from fiber reinforced thermoplastic sandwich panels

    Science.gov (United States)

    Donnelly, Mathew William; Kasoff, William Andrew; Mcculloch, Patrick Carl; Williams, Frederick Truman

    2007-12-25

    An improved, load bearing, modular design container structure assembled from thermoformed FRTP sandwich panels in which is utilized the unique core-skin edge configuration of the present invention in consideration of improved load bearing performance, improved useful load volume, reduced manufacturing costs, structural weight savings, impact and damage tolerance and repair and replace issues.

  16. Human Assisted Assembly Processes

    Energy Technology Data Exchange (ETDEWEB)

    CALTON,TERRI L.; PETERS,RALPH R.

    2000-01-01

    Automatic assembly sequencing and visualization tools are valuable in determining the best assembly sequences, but without Human Factors and Figure Models (HFFMs) it is difficult to evaluate or visualize human interaction. In industry, accelerating technological advances and shorter market windows have forced companies to turn to an agile manufacturing paradigm. This trend has promoted computerized automation of product design and manufacturing processes, such as automated assembly planning. However, all automated assembly planning software tools assume that the individual components fly into their assembled configuration and generate what appear to be a perfectly valid operations, but in reality the operations cannot physically be carried out by a human. Similarly, human figure modeling algorithms may indicate that assembly operations are not feasible and consequently force design modifications; however, if they had the capability to quickly generate alternative assembly sequences, they might have identified a feasible solution. To solve this problem HFFMs must be integrated with automated assembly planning to allow engineers to verify that assembly operations are possible and to see ways to make the designs even better. Factories will very likely put humans and robots together in cooperative environments to meet the demands for customized products, for purposes including robotic and automated assembly. For robots to work harmoniously within an integrated environment with humans the robots must have cooperative operational skills. For example, in a human only environment, humans may tolerate collisions with one another if they did not cause much pain. This level of tolerance may or may not apply to robot-human environments. Humans expect that robots will be able to operate and navigate in their environments without collisions or interference. The ability to accomplish this is linked to the sensing capabilities available. Current work in the field of cooperative

  17. High Energy X-ray Study on Nondestructive Detection of Fuel Assemblies

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Xiang-yang; WANG; Guo-bao; HE; Gao-kui; CUI; Yao; ZENG; Zi-qiang; ZHANG; Li-feng; LIANG; Zheng-qiang; YIN; Zhen-guo; WANG; Xin

    2015-01-01

    Nuclear fuel assemblies are the core of nuclear facilities,and the safety and effective operation of nuclear fuel assembly under complicated environment in reactor is the most important issue of guarantee of nuclear facility.In order to better research and analyze complete behavior of nuclear

  18. Physics Design of Water Moderator Criticality Assembly in Experimental Research About ADS

    Institute of Scientific and Technical Information of China (English)

    LV; Niu

    2013-01-01

    In order to meet the experimental demand of ADS research,we need to design a suitable criticality assembly.The key problem of the design work is the core design,we design a criticality assembly with the water moderator according to available nuclear material(Fig.1).The theoretical calculation have been

  19. Modeling electronegative plasma discharge

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenberg, A.J.; Lieberman, M.A. [Univ. of California, Berkley, CA (United States)

    1995-12-31

    Macroscopic analytic models for a three-component electronegative gas discharge are developed. Assuming the negative ions to be in Boltzmann equilibrium, a positive ion ambipolar diffusion equation is derived. The discharge consists of an electronegative core and electropositive edges. The electron density in the core is nearly uniform, allowing a parabolic approximation to the plasma profile to be employed. The resulting equilibrium equations are solved analytically and matched to a constant mobility transport model of an electropositive edge plasma. The solutions are compared to a simulation of a parallel-plane r.f. driven oxygen plasma for p = 50 mTorr and n{sub eo}= 2.4 x 10{sup 15} m{sup -3}. The ratio {alpha}{sub o} of central negative ion density to electron density, and the electron temperature T{sub e}, found in the simulation, are in reasonable agreement with the values calculated from the model. The model is extended to: (1) low pressures, where a variable mobility model is used in the electropositive edge region; and (2) high {alpha}{sub o} in which the edge region disappears. The inclusion of a second positive ion species, which can be very important in describing electronegative discharges used for materials processing, is a possible extension of the model.

  20. Modular Product Families and Assembly Systems

    DEFF Research Database (Denmark)

    Thyssen, Jesper

    2005-01-01

    This research centres on assembly systems designed for utilizing product modularization. Altogether, the task for companies has become an issue of managing the overall trade-off between the external market’s desire for variety and the internal efficiency and effectiveness. Product modularization...... of the rela-tionship between variables associated with configuration of modular product families and the interacting assembly system. One core result is the development of a system model based on the longitudinal case study incorporating both structural and performance elements. Based on the system model......) the mix flexible con-figuration focusing on the simultaneous product variety. These two views are in particular different in respect to the understanding of product modularization. All in all, modularization needs to be, and can be, configured in regard to the specific task, which is believed constituting...

  1. Towards negative index self-assembled metamaterials

    CERN Document Server

    Fruhnert, Martin; Lederer, Falk; Rockstuhl, Carsten

    2016-01-01

    We investigate the magnetic response of meta-atoms that can be fabricated by a bottom-up technique. Usually such meta-atoms consist of a dielectric core surrounded by a large number of solid metallic nanoparticles. In contrast to those meta-atoms considered thus far, we study here for the first time hollow metallic nanoparticles (shells). In doing so we solve one of the most pertinent problems of current self-assembled metamaterials, namely implementing meta-atoms with sufficiently large resonance strength and small absorption. Both conditions have to be met for deep sub-wavelength meta-atoms to obtain effectively homogeneous metamaterials which may be meaningfully described by negative material parameters. Eventually we show that by using these findings self-assembled negative index materials come in reach.

  2. HL-2A Tokamak Plasma Visible Light Imaging System

    Institute of Scientific and Technical Information of China (English)

    ZHENGYinjia; FENGZhen; LUOCuiwen; CHENGLiaoyuan

    2003-01-01

    Visible imagery is extremely useful to overview the edge and divertor structure. The plasma configuration and the position of the strike lines on the target plates can be also observed by imaging technique. By imaging the edge or core plasma with visible emission in the desired wavelength band, usually with a “tangential” view, the plasma position can be determined in principle.

  3. Assembly & Metrology of First Wall Components of SST-1

    Science.gov (United States)

    Parekh, Tejas; Santra, Prosenjit; Biswas, Prabal; Patel, Hiteshkumar; Paravastu, Yuvakiran; Jaiswal, Snehal; Chauhan, Pradeep; Babu, Gattu Ramesh; A, Arun Prakash; Bhavsar, Dhaval; Raval, Dilip C.; Khan, Ziauddin; Pradhan, Subrata

    2017-04-01

    First Wall Components (FWC) of SST-1 tokamak, which are in the immediate vicinity of plasma comprises of limiters, divertors, baffles, passive stabilizers are designed to operate long duration (1000 s) discharges of elongated plasma. All FWC consists of a copper alloy heat sink modules with SS cooling tubes brazed onto it, graphite tiles acting as armour material facing the plasma, and are mounted to the vacuum vessels with suitable Inconel support structures at ring & port locations. The FWC are very recently assembled and commissioned successfully inside the vacuum vessel of SST-1 undergoing a meticulous planning of assembly sequence, quality checks at every stage of the assembly process. This paper will present the metrology aspects & procedure of each FWC, both outside the vacuum vessel, and inside the vessel, assembly tolerances, tools, equipment and jig/fixtures, used at each stage of assembly, starting from location of support bases on vessel rings, fixing of copper modules on support structures, around 3800 graphite tile mounting on 136 copper modules with proper tightening torques, till final toroidal and poloidal geometry of the in-vessel components are obtained within acceptable limits, also ensuring electrical continuity of passive stabilizers to form a closed saddle loop, electrical isolation of passive stabilizers from vacuum vessel.

  4. Computerised analysis of standardised ultrasonographic images to monitor the repair of surgically created core lesions in equine superficial digital flexor tendons following treatment with intratendinous platelet rich plasma or placebo.

    Science.gov (United States)

    Bosch, Gerco; René van Weeren, P; Barneveld, Ab; van Schie, Hans T M

    2011-01-01

    The effectiveness of new therapies to treat tendon injuries is difficult to determine and is often based on semi-quantitative methods, such as grey level analysis of ultrasonographic images or subjective pain scores. The alternatives are costly and long-lasting end-stage studies using experimental animals. In this study, a method of ultrasonographic tissue characterisation (UTC), using mathematical analysis of contiguous transverse ultrasonographic images, was used for intra-vital monitoring of the healing trajectory of standardised tendon lesions treated with platelet rich plasma (PRP) or placebo. Using UTC it was possible to detect significant differences between the groups in the various phases of repair. At end stage, over 80% of pixels showed correct alignment in the PRP group, compared with just over 60% in the placebo group (Ptendon lesions in horses.

  5. The Alignment and Assembly for EAST Tokamak Device

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    EAST (HT-7U) is a large fusion experimental device. It is a full superconducting tokamak with 1 MA of plasma current, 1000 s of plasma duration, high elongation and triangularity. It mainly consists of superconducting magnets of poloidal and toroidal field (PF& TF),vacuum vessel (VV), thermal radiation shield (TRS) and cryostat vessel (CV). The significant difficulty for assembly of EAST is tight installation tolerances, which are in the order of several tenth of a millimeter. In particular, the alignment of plasma facing components to the magnetic axis of the device is less than ± 0.5 mm.At present, a reasonable assembly process of EAST has been defined, and based on it, the alignment method for EAST, including the survey control network, the location of the main components in different directions, the magnetic axis determination and the accurate positioning of the plasma facing components inside of the vacuum vessel and so on, has been defined by using the sophisticated optical metrology system (SOMS).This paper describes the assembly procedure of EAST and the installation tolerances associated with the main components. Meanwhile, how to establish the assembly survey control network,magnetic axis determination methods, are introduced in detail.

  6. Insights into eisosome assembly and organization

    Indian Academy of Sciences (India)

    Murphy Er; Kim Kt

    2012-06-01

    Eisosomes, large protein complexes that are predominantly composed of BAR-domain-containing proteins Pil1 and its homologs, are situated under the plasma membrane of ascomycetes. A successful targeting of Pil1 onto the future site of eisosome accompanies maturation of eisosome. During or after recruitment, Pil1 undergoes self-assembly into filaments that can serve as scaffolds to induce membrane furrows or invaginations. Although a consequence of the invagination is likely to redistribute particular proteins and lipids to a different location, the precise physiological role of membrane invagination and eisosome assembly awaits further investigation. The present review summarizes recent research findings within the field regarding the detailed structural and functional significance of Pil1 on eisosome organization.

  7. Photovoltaic self-assembly.

    Energy Technology Data Exchange (ETDEWEB)

    Lavin, Judith; Kemp, Richard Alan; Stewart, Constantine A.

    2010-10-01

    This late-start LDRD was focused on the application of chemical principles of self-assembly on the ordering and placement of photovoltaic cells in a module. The drive for this chemical-based self-assembly stems from the escalating prices in the 'pick-and-place' technology currently used in the MEMS industries as the size of chips decreases. The chemical self-assembly principles are well-known on a molecular scale in other material science systems but to date had not been applied to the assembly of cells in a photovoltaic array or module. We explored several types of chemical-based self-assembly techniques, including gold-thiol interactions, liquid polymer binding, and hydrophobic-hydrophilic interactions designed to array both Si and GaAs PV chips onto a substrate. Additional research was focused on the modification of PV cells in an effort to gain control over the facial directionality of the cells in a solvent-based environment. Despite being a small footprint research project worked on for only a short time, the technical results and scientific accomplishments were significant and could prove to be enabling technology in the disruptive advancement of the microelectronic photovoltaics industry.

  8. Plasma Antenna

    OpenAIRE

    N M Vijay

    2014-01-01

    The fundamental base of plasma antenna is the use of an ionized medium as a conductor. The plasma antenna is a radiofrequency antenna formed by a plasma columns, Filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off, only applying an electrical pulse. Besides its wide carrier frequency, the great directivity and controllable antenna shape. Otherwise a disadvantage is that it needs energy to be ionized....

  9. Environment-based pin-power reconstruction method for homogeneous core calculations

    Energy Technology Data Exchange (ETDEWEB)

    Leroyer, H.; Brosselard, C.; Girardi, E. [EDF R and D/SINETICS, 1 av du General de Gaulle, F92141 Claman Cedex (France)

    2012-07-01

    Core calculation schemes are usually based on a classical two-step approach associated with assembly and core calculations. During the first step, infinite lattice assemblies calculations relying on a fundamental mode approach are used to generate cross-sections libraries for PWRs core calculations. This fundamental mode hypothesis may be questioned when dealing with loading patterns involving several types of assemblies (UOX, MOX), burnable poisons, control rods and burn-up gradients. This paper proposes a calculation method able to take into account the heterogeneous environment of the assemblies when using homogeneous core calculations and an appropriate pin-power reconstruction. This methodology is applied to MOX assemblies, computed within an environment of UOX assemblies. The new environment-based pin-power reconstruction is then used on various clusters of 3x3 assemblies showing burn-up gradients and UOX/MOX interfaces, and compared to reference calculations performed with APOLLO-2. The results show that UOX/MOX interfaces are much better calculated with the environment-based calculation scheme when compared to the usual pin-power reconstruction method. The power peak is always better located and calculated with the environment-based pin-power reconstruction method on every cluster configuration studied. This study shows that taking into account the environment in transport calculations can significantly improve the pin-power reconstruction so far as it is consistent with the core loading pattern. (authors)

  10. Plasma physics

    CERN Document Server

    Drummond, James E

    2013-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  11. DWPF GC FILTER ASSEMBLY SAMPLING AND ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C.; Imrich, K.

    2009-11-11

    On March 18, 2009 a Defense Waste Processing Facility (DWPF) GC Line Filter Assembly was received at the Savannah River National Laboratory (SRNL). This filter assembly was removed from operation following the completion of Sludge Batch 4 processing in the DWPF. Work on this sample was requested in a Technical Assistance Request. This document reports the pictures, observations, samples collected, and analytical results for the assembly. The assembly arrived at SRNL separated into its three component filters: high efficiency particulate air (HEPA)-1, HEPA-2, and a high efficiency mist evaporator (HEME). Each stage of the assembly's media was sampled and examined visually and by scanning electron microscopy (SEM). Solids built up in the filter housing following the first stage HEME, were dissolved in dilute nitric acid and analyzed by ICP-AES and the undissolved white solids were analyzed by x-ray diffraction (XRD). The vast majority of the material in each of the three stages of the DWPF GC Line Filter Assembly appears to be contaminated with a Hg compound that is {approx}59 wt% Hg on a total solids basis. The Hg species was identified by XRD analysis to contain a mixture of Hg{sub 4}(OH)(NO{sub 3}){sub 3} and Hg{sub 10}(OH){sub 4}(NO{sub 3}){sub 6}. Only in the core sample of the second stage HEPA, did this material appear to be completely covering portions of the filter media, possibly explaining the pressure drops observed by DWPF. The fact that the material migrates through the HEME filter and both HEPA filters, and that it was seen collecting on the outlet side of the HEME filter, would seem to indicate that these filters are not efficient at removing this material. Further SRAT off-gas system modeling should help determine the extent of Hg breakthrough past the Mercury Water Wash Tank (MWWT). The SRAT off-gas system has not been modeled since startup of the facility. Improvements to the efficiency of Hg stripping prior to the ammonia scrubber would seem

  12. In vitro kinetochore assembly

    Science.gov (United States)

    Miell, Matthew D D; Straight, Aaron F

    2016-01-01

    The kinetochore is the primary site of interaction between chromosomes and microtubules of the mitotic spindle during chromosome segregation. The kinetochore is a complex of more than 100 proteins that transiently assemble during mitosis at a single defined region on each chromosome, known as the centromere. Kinetochore assembly and activity must be tightly regulated to ensure proper microtubule interaction and faithful chromosome segregation because perturbation of kinetochores often results in aneuploidy and cell lethality. As such, cell free and reconstituted systems to analyze kinetochore formation and function are invaluable in probing the biochemical activities of kinetochores. In vitro approaches to studying kinetochores have enabled the manipulation of kinetochore protein structure, function, interactions and regulation that are not possible in cells. Here we outline a cell-free approach for the assembly of centromeres and recruitment of functional kinetochores that enables their manipulation and analysis. PMID:27193846

  13. Assembling Sustainable Territories

    DEFF Research Database (Denmark)

    Vandergeest, Peter; Ponte, Stefano; Bush, Simon

    2015-01-01

    The authors show how certification assembles ‘sustainable’ territories through a complex layering of regulatory authority in which both government and nongovernment entities claim rule-making authority, sometimes working together, sometimes in parallel, sometimes competitively. It is argued...... that territorialisation is accomplished not just through (re)defining bounded space, but more broadly through the assembling of four elements: space, subjects, objects, and expertise. Four case studies of sustainability certification in seafood are analyzed to show that ‘green gabbing’ is not necessarily the central...... dynamic in assembling sustainable territories, and that certification always involves state agencies in determining how the key elements that comprise it are defined. Whereas some state agencies have been suspicious of sustainability certification, others have embraced it or even used it to extend...

  14. Power module assembly

    Science.gov (United States)

    Campbell, Jeremy B [Torrance, CA; Newson, Steve [Redondo Beach, CA

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  15. Blade attachment assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  16. The core paradox.

    Science.gov (United States)

    Kennedy, G. C.; Higgins, G. H.

    1973-01-01

    Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

  17. K-core inflation

    OpenAIRE

    Alexander L. Wolman

    2011-01-01

    K-core inflation is a new class of underlying inflation measures. The two most popular measures of underlying inflation are core inflation and trimmed mean inflation. The former removes fixed categories of goods and services (food and energy) from the inflation calculation, and the latter removes fixed percentiles of the weighted distribution of price changes. In contrast, k-core inflation specifies a size of relative price change to be removed from the inflation calculation. Thus, the catego...

  18. ROSA full-core and DNBR capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Gibcus, H.P.M.; Verhagen, F.C.M.; Wakker, P.H. [NRG, Arnhem (Netherlands)

    2012-11-01

    This paper presents the latest developments of the ROSA (Reloading Optimization by Simulated Annealing) code system with an emphasis on the first full-core version and the minimum DNBR (Departure from Nucleate Boiling Ratio) as a new optimization parameter. Designing the core loading pattern of nuclear power plants is becoming a more and more complex task. This task becomes even more complicated if asymmetries in the core loading pattern arise, for instance due to damaged fuel assemblies. For over almost two decades ROSA, NRG's (Nuclear Research and consultancy Group) loading pattern optimization code system for PWRs, has proven to be a valuable tool to reactor operators in accomplishing this task. To improve the use of ROSA for designing asymmetric loading patterns, NRG has developed a full-core version of ROSA besides the original quarter-core version which requires rotational symmetry in the computational domain. The extension of ROSA with DNBR as an optimization parameter is part of ROSA's continuous development. (orig.)

  19. ROSA full-core and DNBR capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Gibcus, H.P.M.; Verhagen, F.C.M.; Wakker, P.H. [NRG, Arnhem (Netherlands)

    2013-06-15

    The latest developments of the ROSA (Reloading Optimization by Simulated Annealing) code system with an emphasis on the first full-core version and the minimum DNBR (Departure from Nucleate Boiling Ratio) as a new optimization parameter are presented. Designing the core loading pattern of nuclear power plants is becoming a more and more complex task. This task becomes even more complicated if asymmetries in the core loading pattern arise, for instance due to damaged fuel assemblies. For over almost 2 decades ROSA, NRG's (Nuclear Research and consultancy Group) loading pattern optimization code system for PWRs, has proven to be a valuable tool to reactor operators in accomplishing this task. To improve the use of ROSA for designing asymmetric loading patterns, NRG has developed a full-core version of ROSA besides the original quarter-core version which requires rotational symmetry in the computational domain. The extension of ROSA with DNBR as an optimization parameter is part of ROSA's continuous development. (orig.)

  20. Physics Design of Criticality Assembly in Experimental Research About Criticality Safety in Spent Fuel Dissolver

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Qi

    2012-01-01

    <正>In order to meet the experimental demand of criticality safety research in the spent fuel dissolver, we need to design a suitable criticality assembly. The key problem of the design work is the core design because there are many limits for it such as the number of fuel rods loaded, fissile materials existed in the solution, reactivity control, core size and etc.

  1. Sediment Core Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation and expertise for physical and geoacoustic characterization of marine sediments. DESCRIPTION: The multisensor core logger measures...

  2. Sediment Core Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation and expertise for physical and geoacoustic characterization of marine sediments.DESCRIPTION: The multisensor core logger measures...

  3. Low inductance connector assembly

    Science.gov (United States)

    Holbrook, Meghan Ann; Carlson, Douglas S

    2013-07-09

    A busbar connector assembly for coupling first and second terminals on a two-terminal device to first and second contacts on a power module is provided. The first terminal resides proximate the first contact and the second terminal resides proximate the second contact. The assembly comprises a first bridge having a first end configured to be electrically coupled to the first terminal, and a second end configured to be electrically coupled to the second contact, and a second bridge substantially overlapping the first bridge and having a first end electrically coupled to the first contact, and a second end electrically coupled to the second terminal.

  4. Self assembling proteins

    Science.gov (United States)

    Yeates, Todd O.; Padilla, Jennifer; Colovos, Chris

    2004-06-29

    Novel fusion proteins capable of self-assembling into regular structures, as well as nucleic acids encoding the same, are provided. The subject fusion proteins comprise at least two oligomerization domains rigidly linked together, e.g. through an alpha helical linking group. Also provided are regular structures comprising a plurality of self-assembled fusion proteins of the subject invention, and methods for producing the same. The subject fusion proteins find use in the preparation of a variety of nanostructures, where such structures include: cages, shells, double-layer rings, two-dimensional layers, three-dimensional crystals, filaments, and tubes.

  5. Assembling an aesthetic.

    Science.gov (United States)

    Candela, Emily

    2012-12-01

    Recent research informing and related to the study of three-dimensional scientific models is assembled here in a way that explores an aesthetic, specifically, of touch. I concentrate on the materiality of models, drawing on insights from the history and philosophy of science, design and metaphysics. This article chronicles the ways in which touch, or material interactions, operate in the world of 3D models, and its role in what models mean and do. I end with a call for greater attention to scientific process, described as assembly of and within science, which is revealed by this focus on touch. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Modern X86 assembly language programming 32-bit, 64-bit, SSE, and AVX

    CERN Document Server

    Kusswurm, Daniel

    2014-01-01

    Modern X86 Assembly Language Programming shows the fundamentals of x86 assembly language programming. It focuses on the aspects of the x86 instruction set that are most relevant to application software development. The book's structure and sample code are designed to help the reader quickly understand x86 assembly language programming and the computational capabilities of the x86 platform. Major topics of the book include the following: 32-bit core architecture, data types, internal registers, memory addressing modes, and the basic instruction setX87 core architecture, register stack, special

  7. Liquid Core Waveguides by UV Modification of Nanoporous Polymer

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Gopalakrishnan, Nimi; Sagar, Kaushal Shashikant

    2011-01-01

    Liquid core waveguides are fabricated from a self-assembled nanoporous polymer, with a porosity of 40%. The high porosity results in an effective refractive index of 1.26 for visible light, i.e. below the refractive index of aqueous solutions. However, since the polymer is hydrophobic, fluids...

  8. An Interactive Assembly Process Planner

    Institute of Scientific and Technical Information of China (English)

    廖华飞; 张林鍹; 肖田元; 曾理; 古月

    2004-01-01

    This paper describes the implementation and performance of the virtual assembly support system (VASS), a new system that can provide designers and assembly process engineers with a simulation and visualization environment where they can evaluate the assemblability/disassemblability of products, and thereby use a computer to intuitively create assembly plans and interactively generate assembly process charts. Subassembly planning and assembly priority reasoning techniques were utilized to find heuristic information to improve the efficiency of assembly process planning. Tool planning was implemented to consider tool requirements in the product design stage. New methods were developed to reduce the computation amount involved in interference checking. As an important feature of the VASS, human interaction was integrated into the whole process of assembly process planning, extending the power of computer reasoning by including human expertise, resulting in better assembly plans and better designs.

  9. Fire resistant PV shingle assembly

    Science.gov (United States)

    Lenox, Carl J.

    2012-10-02

    A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

  10. Self-assembly of plasma protein as a nanocarrier for lipophilic drugs%血浆蛋白-脂溶性药物纳米载体体系的自组装

    Institute of Scientific and Technical Information of China (English)

    龚光明; 陈美惠; 曹燕丽; 王曙东

    2016-01-01

    Objective Human serum albumin ( HSA) is a kind of plasma protein , which can transport various small molecu-lar substances to the body.A disulfide bond breaking strategy is used to fabricate HSA-curcumin nanoparticles(NPs-CCM) in order to improve the solubility and tumor targeting capability of curcumin . Methods NPs-CCM were fabricated with dithiothreitol as the re-ducing agent .The size and shape of the nanoparticles were observed with high resolution electron microscopy .We explored the change of hydrophobic region during the process of degeneration of albumin , the releasing behavior in the solution and the tumor targeting capa-bility in vivo and vitro of NPs-CCM. Results The diameter of NPs-CCM was about 150 nm.The determination of surface hydropho-bicity showed that ANS fluorescence intensity decreased gradually as the extension of degeneration time , at the time 0 min, 2 min, 5 min and 10 min, ANS relative fluorescence intensity was 5492(5432-5673), 2486(2319-2878), 1998(1904-2317), 1503 (1280-1584) respectively.The hydrophobic region of albumin gradually reduced during the degeneration time .The curcumin re-leased from NPs-CCM amounted to about 50% within 40 h, and the NPs-CCM can be absorbed by tumor cells and accumulation in tumor tissue. Conclusion Albumin can improve the solubility and tumor targeting capability of curcumin , and it has potential clinical application value.%目的:人血清清蛋白是血浆中的一种蛋白质,能够运输各种小分子物质分布全身。二硫键断裂法构建清蛋白姜黄素纳米粒子,以提高姜黄素溶解度及肿瘤靶向性能。方法二硫苏糖醇为变性剂,构建清蛋白姜黄素纳米粒子。高分辨电镜考察粒子的形貌和大小。考察了清蛋白变性过程中疏水区域变化、清蛋白姜黄素粒子在溶液中的释放行为及对肿瘤体内和体外靶向性。结果清蛋白姜黄素纳米粒子大小约150 nm。表面疏水性测量结

  11. A Method for Designing Assembly Tolerance Networks of Mechanical Assemblies

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2012-01-01

    Full Text Available When designing mechanical assemblies, assembly tolerance design is an important issue which must be seriously considered by designers. Assembly tolerances reflect functional requirements of assembling, which can be used to control assembling qualities and production costs. This paper proposes a new method for designing assembly tolerance networks of mechanical assemblies. The method establishes the assembly structure tree model of an assembly based on its product structure tree model. On this basis, assembly information model and assembly relation model are set up based on polychromatic sets (PS theory. According to the two models, the systems of location relation equations and interference relation equations are established. Then, using methods of topologically related surfaces (TTRS theory and variational geometric constraints (VGC theory, three VGC reasoning matrices are constructed. According to corresponding relations between VGCs and assembly tolerance types, the reasoning matrices of tolerance types are also established by using contour matrices of PS. Finally, an exemplary product is used to construct its assembly tolerance networks and meanwhile to verify the feasibility and effectiveness of the proposed method.

  12. Unconventional assembly of bimetallic Au-Ni janus nanoparticles on chemically modified silica spheres.

    Science.gov (United States)

    Jia, Lei; Pei, Xiaowei; Zhou, Feng; Liu, Weimin

    2014-02-10

    This paper reports that Janus Au-Ni nanoparticles (JANNPs) can self-assemble onto silica spheres in a novel way, which is different from that of single-component isotropic nanoparticles. JANNPs modified with octadecylamine (ODA) assemble onto catechol-modified silica spheres (SiO2-OH) to form a very special core-loop complex structure and finally the core-loop assemblies link each other to form large assemblies through capillary force and the hydrophobic interaction of the alkyl chains of ODA. The nanocomposites disassemble in the presence of vanillin and oleic acid because of the breakage of the catechol-metal link. Vanillin-induced disassembly enables the JANNPs to reassemble into a core-loop structure upon ODA addition. The assembly of SiO2-OH and isotropic Ni or Fe3O4 particles generates traditional core-satellite structures. This unconventional self-assembly can be attributed to the synergistic effect of Janus specificity and capillary force, which is also confirmed by the assembly of thiol-terminated silica spheres (SH-SiO2) with anisotropic JANNPs, isotropic Au, and Ni nanoparticles. These results can guide the development of novel composite materials using Janus nanoparticles as the primary building blocks. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Industrial Assembly Cases

    DEFF Research Database (Denmark)

    Ellekilde, Lars-Peter; Buch, Jacob Pørksen; Iversen, Thorbjørn Mosekjær;

    This technical report presents 13 different industrial assembly tasks, which are composed of 70 different operations. The report is written to provide an overview and do as such not contain product specific information such as object weights, dimensions etc. The operations are classified into a set...

  14. Assembling Sustainable Territories

    DEFF Research Database (Denmark)

    Vandergeest, Peter; Ponte, Stefano; Bush, Simon

    2015-01-01

    that territorialisation is accomplished not just through (re)defining bounded space, but more broadly through the assembling of four elements: space, subjects, objects, and expertise. Four case studies of sustainability certification in seafood are analyzed to show that ‘green gabbing’ is not necessarily the central...

  15. Turbomachine blade assembly

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Crespo, Andres Jose

    2016-11-01

    Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

  16. Assemblies of Polyoxometalates

    NARCIS (Netherlands)

    Veen, S.J.

    2009-01-01

    Assemblies of Polyoxometalates Polyoxometalates, or POMs for short, come in a variety of shapes and sizes. Some of them are among the largest inorganic molecules known today. These molecules can be highly symmetrical and, as the name already implies, consist of (mainly) metal (molybdenum, tungsten,

  17. Ordinary General Assembly

    CERN Document Server

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may r...

  18. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation et and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly ma...

  19. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may require t...

  20. Industrial Assembly Cases

    DEFF Research Database (Denmark)

    Ellekilde, Lars-Peter; Buch, Jacob Pørksen; Iversen, Thorbjørn Mosekjær

    This technical report presents 13 different industrial assembly tasks, which are composed of 70 different operations. The report is written to provide an overview and do as such not contain product specific information such as object weights, dimensions etc. The operations are classified into a set...

  1. Metaphase Spindle Assembly

    Directory of Open Access Journals (Sweden)

    Tarun M. Kapoor

    2017-02-01

    Full Text Available A microtubule-based bipolar spindle is required for error-free chromosome segregation during cell division. In this review I discuss the molecular mechanisms required for the assembly of this dynamic micrometer-scale structure in animal cells.

  2. Dump valve assembly

    Science.gov (United States)

    Owen, T.J.

    1984-01-01

    A dump valve assembly comprising a body having a bore defined by a tapered wall and a truncated spherical valve member adapted to seat along a spherical surface portion thereof against said tapered wall. Means are provided for pivoting said valve member between a closed position engagable with said tapered wall and an open position disengaged therefrom.

  3. Supramolecular Assemblies in Photosynthesis

    Science.gov (United States)

    Wrachtrup, J.; Tietz, C.; Jelezko, F.; Gerken, U.; Schuler, S.; Götze, B.; Volkmer, A.

    2002-10-01

    The photosynthetic apparatus contains a wealth of supramolecular assemblies that are optimized for charge and energy transfer. Various techniques have been applied to investigate these functions that rely on the electronic interaction among pigment molecules. In this contribution we will present single-molecule studies of pigment protein complexes. They reveal new information about electronic interactions between chlorophyll molecules in light harvesting complexes.

  4. Beyond the Assembly Line.

    Science.gov (United States)

    Weitz, Rebecca; Guild, Todd

    1985-01-01

    Describes how Hughes Aircraft trainers followed four steps in meeting the challenges of a flexible manufacturing environment: needs assessment, design strategy, pilot evaluation, and follow-through. Within this environment, 50 self-paced training products were developed for one of the company's wire and back plane harness assembly departments. (CT)

  5. America's Assembly Line

    DEFF Research Database (Denmark)

    Nye, David Edwin

    A social history of the assembly line, invented in 1913. Both praised as a boon to consumers and as a curse for workers, it has been satirized, imitated, and celebrated for 100 years. It has inspired fiction, comedy, cafeteria layouts, and suburban housing. It transformed industrial labor...

  6. America's Assembly Line

    DEFF Research Database (Denmark)

    Nye, David Edwin

    A social history of the assembly line, invented in 1913. Both praised as a boon to consumers and as a curse for workers, it has been satirized, imitated, and celebrated for 100 years. It has inspired fiction, comedy, cafeteria layouts, and suburban housing. It transformed industrial labor and pro...

  7. Ice Core Investigations

    Science.gov (United States)

    Krim, Jessica; Brody, Michael

    2008-01-01

    What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air…

  8. Making an Ice Core.

    Science.gov (United States)

    Kopaska-Merkel, David C.

    1995-01-01

    Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)

  9. Ice Core Investigations

    Science.gov (United States)

    Krim, Jessica; Brody, Michael

    2008-01-01

    What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air…

  10. Iowa Core Annual Report

    Science.gov (United States)

    Iowa Department of Education, 2015

    2015-01-01

    One central component of a great school system is a clear set of expectations, or standards, that educators help all students reach. In Iowa, that effort is known as the Iowa Core. The Iowa Core represents the statewide academic standards, which describe what students should know and be able to do in math, science, English language arts, and…

  11. Mercury's core evolution

    Science.gov (United States)

    Deproost, Marie-Hélène; Rivoldini, Attilio; Van Hoolst, Tim

    2016-10-01

    Remote sensing data of Mercury's surface by MESSENGER indicate that Mercury formed under reducing conditions. As a consequence, silicon is likely the main light element in the core together with a possible small fraction of sulfur. Compared to sulfur, which does almost not partition into solid iron at Mercury's core conditions and strongly decreases the melting temperature, silicon partitions almost equally well between solid and liquid iron and is not very effective at reducing the melting temperature of iron. Silicon as the major light element constituent instead of sulfur therefore implies a significantly higher core liquidus temperature and a decrease in the vigor of compositional convection generated by the release of light elements upon inner core formation.Due to the immiscibility in liquid Fe-Si-S at low pressure (below 15 GPa), the core might also not be homogeneous and consist of an inner S-poor Fe-Si core below a thinner Si-poor Fe-S layer. Here, we study the consequences of a silicon-rich core and the effect of the blanketing Fe-S layer on the thermal evolution of Mercury's core and on the generation of a magnetic field.

  12. Atmospheric pressure plasma processing of polymeric materials utilizing close proximity indirect exposure

    Energy Technology Data Exchange (ETDEWEB)

    Paulauskas, Felix L.; Bonds, Truman

    2016-09-20

    A plasma treatment method that includes providing treatment chamber including an intermediate heating volume and an interior treatment volume. The interior treatment volume contains an electrode assembly for generating a plasma and the intermediate heating volume heats the interior treatment volume. A work piece is traversed through the treatment chamber. A process gas is introduced to the interior treatment volume of the treatment chamber. A plasma is formed with the electrode assembly from the process gas, wherein a reactive species of the plasma is accelerated towards the fiber tow by flow vortices produced in the interior treatment volume by the electrode assembly.

  13. Dosimetry Evaluation of In-Core and Above-Core Zirconium Alloy Samples in a PWR

    Directory of Open Access Journals (Sweden)

    Amiri Benjamin W.

    2016-01-01

    Full Text Available A description of the neutron fluence analysis of activated zirconium alloys samples at a Westinghouse 3-loop reactor is presented. These samples were irradiated in the core and in the fuel plenum region, where dosimetry measurements are relatively rare compared with regions radially outward of the core. Dosimetry measurements performed by Batelle/PNNL are compared to the calculational models. Good agreement is shown with the in-core measurements when using analysis conditions expected to best represent this region, such as an assembly-specific axial power distribution. However, the use of these conditions to evaluate dosimetry in the fuel plenum region can lead to significant underestimation of the fluence. The use of a flat axial power distribution, however, does not underestimate the fluence in the fuel plenum region.

  14. Mars' core and magnetism.

    Science.gov (United States)

    Stevenson, D J

    2001-07-12

    The detection of strongly magnetized ancient crust on Mars is one of the most surprising outcomes of recent Mars exploration, and provides important insight about the history and nature of the martian core. The iron-rich core probably formed during the hot accretion of Mars approximately 4.5 billion years ago and subsequently cooled at a rate dictated by the overlying mantle. A core dynamo operated much like Earth's current dynamo, but was probably limited in duration to several hundred million years. The early demise of the dynamo could have arisen through a change in the cooling rate of the mantle, or even a switch in convective style that led to mantle heating. Presently, Mars probably has a liquid, conductive outer core and might have a solid inner core like Earth.

  15. Magnetic Field Generation in Core-Sheath Jets via the Kinetic Kelvin-Helmholtz Instability

    CERN Document Server

    Nishikawa, K -I; Dutan, I; Niemiec, J; Medvedev, M; Mizuno, Y; Meli, A; Sol, H; Zhang, B; Pohl, M; Hartmann, D H

    2014-01-01

    We have investigated magnetic field generation in velocity shears via the kinetic Kelvin-Helmholtz instability (kKHI) using a relativistic plasma jet core and stationary plasma sheath. Our three-dimensional particle-in-cell simulations consider plasma jet cores with Lorentz factors of 1.5, 5, and 15 for both electron-proton and electron-positron plasmas. For electron-proton plasmas we find generation of strong large-scale DC currents and magnetic fields which extend over the entire shear-surface and reach thicknesses of a few tens of electron skin depths. For electron-positron plasmas we find generation of alternating currents and magnetic fields. Jet and sheath plasmas are accelerated across the shear surface in the strong magnetic fields generated by the kKHI. The mixing of jet and sheath plasmas generates transverse structure similar to that produced by the Weibel instability.

  16. Magnetic field generation in core-sheath jets via the kinetic Kelvin-Helmholtz instability

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, K.-I. [Department of Physics, University of Alabama in Huntsville, ZP12, Huntsville, AL 35899 (United States); Hardee, P. E. [Department of Physics and Astronomy, The University of Alabama, Tuscaloosa, AL 35487 (United States); Duţan, I. [Institute of Space Science, Atomistilor 409, Bucharest-Magurele RO-077125 (Romania); Niemiec, J. [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Medvedev, M. [Department of Physics and Astronomy, University of Kansas, KS 66045 (United States); Mizuno, Y. [Institute of Astronomy, National Tsing-Hua University, Hsinchu, Taiwan 30013 (China); Meli, A. [Department of Physics and Astronomy, University of Gent, Proeftuinstraat 86 B-9000, Gent (Belgium); Sol, H. [LUTH, Observatore de Paris-Meudon, 5 place Jules Jansen, F-92195 Meudon Cedex (France); Zhang, B. [Department of Physics, University of Nevada, Las Vegas, NV 89154 (United States); Pohl, M. [Institut fur Physik und Astronomie, Universität Potsdam, D-14476 Potsdam-Golm (Germany); Hartmann, D. H., E-mail: ken-ichi.nishikawa@nasa.gov [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States)

    2014-09-20

    We have investigated magnetic field generation in velocity shears via the kinetic Kelvin-Helmholtz instability (kKHI) using a relativistic plasma jet core and stationary plasma sheath. Our three-dimensional particle-in-cell simulations consider plasma jet cores with Lorentz factors of 1.5, 5, and 15 for both electron-proton and electron-positron plasmas. For electron-proton plasmas, we find generation of strong large-scale DC currents and magnetic fields that extend over the entire shear surface and reach thicknesses of a few tens of electron skin depths. For electron-positron plasmas, we find generation of alternating currents and magnetic fields. Jet and sheath plasmas are accelerated across the shear surface in the strong magnetic fields generated by the kKHI. The mixing of jet and sheath plasmas generates a transverse structure similar to that produced by the Weibel instability.

  17. The t-core of an s-core

    OpenAIRE

    Fayers, Matthew

    2010-01-01

    We consider the $t$-core of an $s$-core partition, when $s$ and $t$ are coprime positive integers. Olsson has shown that the $t$-core of an $s$-core is again an $s$-core, and we examine certain actions of the affine symmetric group on $s$-cores which preserve the $t$-core of an $s$-core. Along the way, we give a new proof of Olsson's result. We also give a new proof of a result of Vandehey, showing that there is a simultaneous $s$- and $t$-core which contains all others.

  18. The t-core of an s-core

    OpenAIRE

    Fayers, Matthew

    2010-01-01

    We consider the $t$-core of an $s$-core partition, when $s$ and $t$ are coprime positive integers. Olsson has shown that the $t$-core of an $s$-core is again an $s$-core, and we examine certain actions of the affine symmetric group on $s$-cores which preserve the $t$-core of an $s$-core. Along the way, we give a new proof of Olsson's result. We also give a new proof of a result of Vandehey, showing that there is a simultaneous $s$- and $t$-core which contains all others.

  19. The influence of reactor core parameters on effective breeding coefficient Keff

    Institute of Scientific and Technical Information of China (English)

    Liu Li-Po; Liu Yi-Bao; Wang Juan; Yang Bo; Zhang Tao

    2008-01-01

    The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters (core structure, fuel assembly component) by using the Monte Carlo method. The obtained values of Keff are compared and analysed, which can provide theoretical basis for reactor design.

  20. Top-down assembly design using assembly features

    Institute of Scientific and Technical Information of China (English)

    石万凯; DENEUX; Dominique; 等

    2002-01-01

    The primary task of top-down assembly desig is to define a product's detailed physical description satisfying its functional requirements identified during the functional design phase.The implementation of this design process requires two things,that is ,product functional representation and a general assembly model.Product functions are not only the formulation of a customer's needs,but also the input data of assembly design.A general assembly model is to support the evolving process of the elaboration of a product structure.The assembly feature of extended concept is taken as a functional carrier,which is a generic relation among assembly-modeled entities.The model of assembly features describes the link between product functions and form features of parts.On the basis of this link,the propagation of design modifications is discussed so as to preserve the functionality and the coherence of the assembly model.The formal model of assembly design process describes the top-down process of creating an assembly model.This formal model is represented by the combination of assembly feature operations,the assembly model and the evaluation process.A design case study is conducted to verify the applicability of the presented approaches.

  1. Dynamic assembly of molecularly imprinted polymer nanoparticles.

    Science.gov (United States)

    Gong, Haiyue; Hajizadeh, Solmaz; Jiang, Lingdong; Ma, Huiting; Ye, Lei

    2017-09-11

    Manipulation of specific binding and recycling of materials are two important aspects for practical applications of molecularly imprinted polymers. In this work, we developed a new approach to control the dynamic assembly of molecularly imprinted nanoparticles by surface functionalization. Molecularly imprinted polymer nanoparticles with a well-controlled core-shell structure were synthesized using precipitation polymerization. The specific binding sites were created in the core during the first step imprinting reaction. In the second polymerization step, epoxide groups were introduced into the particle shell to act asan intermediate linker to immobilize phenylboronic acids, as well as to introduce cis-diol structures on surface. The imprinted polymer nanoparticles modified with boronic acid and cis-diol structures maintained high molecular binding specificity, and the nanoparticles could be induced to form dynamic particle aggregation that responded to pH variation and chemical stimuli. The possibility of modulating molecular binding and nanoparticle assembly in a mutually independent fashion can be exploited in a number of applications where repeated use of precious nanoparticles is needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Modular assembly of yeast cytochrome oxidase.

    Science.gov (United States)

    McStay, Gavin P; Su, Chen Hsien; Tzagoloff, Alexander

    2013-02-01

    Previous studies of yeast cytochrome oxidase (COX) biogenesis identified Cox1p, one of the three mitochondrially encoded core subunits, in two high-molecular weight complexes combined with regulatory/assembly factors essential for expression of this subunit. In the present study we use pulse-chase labeling experiments in conjunction with isolated mitochondria to identify new Cox1p intermediates and place them in an ordered pathway. Our results indicate that before its assimilation into COX, Cox1p transitions through five intermediates that are differentiated by their compositions of accessory factors and of two of the eight imported subunits. We propose a model of COX biogenesis in which Cox1p and the two other mitochondrial gene products, Cox2p and Cox3p, constitute independent assembly modules, each with its own complement of subunits. Unlike their bacterial counterparts, which are composed only of the individual core subunits, the final sequence in which the mitochondrial modules associate to form the holoenzyme may have been conserved during evolution.

  3. Korrelasjon mellom core styrke, core stabilitet og utholdende styrke i core

    OpenAIRE

    Berg-Olsen, Andrea Marie; Fugelsøy, Eivor; Maurstad, Ann-Louise

    2010-01-01

    Formålet med studien var å se hvilke korrelasjon det er mellom core styrke, core stabilitet og utholdende styrke i core. Testingen bestod av tre hoveddeler hvor vi testet core styrke, core stabilitet og utholdende styrke i core. Innenfor core styrke og utholdende styrke i core ble tre ulike tester utført. Ved måling av core stabilitet ble det gjennomført kun en test. I core styrke ble isometrisk abdominal fleksjon, isometrisk rygg ekstensjon og isometrisk lateral fleksjon testet. Sit-ups p...

  4. Korrelasjon mellom core styrke, core stabilitet og utholdende styrke i core

    OpenAIRE

    Berg-Olsen, Andrea Marie; Fugelsøy, Eivor; Maurstad, Ann-Louise

    2010-01-01

    Formålet med studien var å se hvilke korrelasjon det er mellom core styrke, core stabilitet og utholdende styrke i core. Testingen bestod av tre hoveddeler hvor vi testet core styrke, core stabilitet og utholdende styrke i core. Innenfor core styrke og utholdende styrke i core ble tre ulike tester utført. Ved måling av core stabilitet ble det gjennomført kun en test. I core styrke ble isometrisk abdominal fleksjon, isometrisk rygg ekstensjon og isometrisk lateral fleksjon testet. Sit-ups p...

  5. Earth's inner core: Innermost inner core or hemispherical variations?

    NARCIS (Netherlands)

    Lythgoe, K. H.; Deuss, A.; Rudge, J. F.; Neufeld, J. A.

    2014-01-01

    The structure of Earth's deep inner core has important implications for core evolution, since it is thought to be related to the early stages of core formation. Previous studies have suggested that there exists an innermost inner core with distinct anisotropy relative to the rest of the inner core.

  6. Earth's inner core: Innermost inner core or hemispherical variations?

    NARCIS (Netherlands)

    Lythgoe, K. H.; Deuss, A.; Rudge, J. F.; Neufeld, J. A.

    2014-01-01

    The structure of Earth's deep inner core has important implications for core evolution, since it is thought to be related to the early stages of core formation. Previous studies have suggested that there exists an innermost inner core with distinct anisotropy relative to the rest of the inner core.

  7. Gadolinia-bearing Assembly Design for Reduction of Critical Boron Concentration in APR 1400

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Shakirah; Wan, Abdul Kahar; Hah, Chang Joo [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of); Seong, Ki Bong; Chang, Do Ik [Korea Nuclear Fuel Company, Daejeon (Korea, Republic of)

    2013-10-15

    The objective of this study is to develop a systematic approach to further reduce CBC at BOC and ultimately making MTC more negative, while maintaining cycle length and keeping pin peaking factor below the 1.55 safety limit. The methodology uses fuel assembly (FA) designs that contain both low and high Gd w/o rods. The APR 1400 fuel assembly and core design for Shin-Kori Unit 3 Cycle 1 (SK3C1), which is of PWR type, is used as reference case. The Gd-bearing assembly types in SK3C1, namely B1, B2, B3, C1, C2, and C3, uses Gd rods with 8 w/o gadolinia (Gd{sub 2}O{sub 3}) admixed in UO{sub 2}, and 2 w/o U-235 enrichment. FA and core depletions are simulated using CASMO 3.0 and MASTER 3.0 design codes, respectively. The methodologies described in Section 2 are applied to assemblies B1, C1 and C3. Interpolation of these assemblies' quadratic model equations is performed using the 0.11 factor to obtain Δk{sub FA} tables for B2, B3 and C2 assemblies. Once the design of all Gd-bearing assemblies are determined, core depletion is simulated. The summary of core depletion results is shown in Table II. It is clear that CBC at BOC is successfully reduced in the optimized core case, as also evident in Fig. 3. The amount of CBC reduction is less than the predicted 300 ppm. This is attributed to neutron leakage in core depletion simulation. The actual Δk{sub FA} computed using results of the optimized core simulation is 0.078, which is well within the 1% error of the quadratic model solutions and close to the analytically calculated value. Thus, the assumption made in Eq. is validated.

  8. Multilevel transport solution of LWR reactor cores

    Energy Technology Data Exchange (ETDEWEB)

    Jose Ignacio Marquez Damian; Cassiano R.E. de Oliveira; HyeonKae Park

    2008-09-01

    This work presents a multilevel approach for the solution of the transport equation in typical LWR assemblies and core configurations. It is based on the second-order, even-parity formulation of the transport equation, which is solved within the framework provided by the finite element-spherical harmonics code EVENT. The performance of the new solver has been compared with that of the standard conjugate gradient solver for diffusion and transport problems on structured and unstruc-tured grids. Numerical results demonstrate the potential of the multilevel scheme for realistic reactor calculations.

  9. Atomic Layer Deposition on Carbon Nanotubes and their Assemblies

    Science.gov (United States)

    Stano, Kelly Lynn

    and defect-free CNTs were shown to produce alumina beads on their surfaces, plasma-treated CNTs with a high concentration of oxygen- containing functional groups on their surface promoted conformal film formation. Furthermore, it was determined that ultrahigh aspect ratio CNT assemblies could be uniformly coated throughout the cross-section by orienting the CNT axes parallel to the direction of precursor flow, as well as by removing any barriers to the pump/purge process such as growth substrates or non-porous sample holders. Heat treatment of CNT-alumina hybrids in air not only led to the crystallization of alumina, but also oxidative removal of CNTs from the core-shell structure. In the case of CNT arrays, this resulted in a weak array of alumina nanotubes. When the same process was applied to alumina-coated CNT foams (CNTFs) however, a robust and resilient aerogel-like material remained post-calcination. Further inspection of this novel material revealed that the foam was made up of a three-dimensional network of interconnect alumina nanotubes resulting from the direct templating of alumina on the CNTF structure. With an average density of 1.2 mg cm-3, it is an order of magnitude lower than the lowest density alumina aerogel reported to date, and is among the lowest density for any inorganic aerogel reported to date as well. The structure, and therefore, properties of these novel foams could be easily tuned by varying the thickness of the alumina coating. Evaluation of the compressive behavior of all foams revealed that their mechanical properties exceed those of various foams with similar densities. This was found to be a result of efficient load transfer through the structure due to good connectivity among nanotube ligaments. This connectivity also provided unprecedented elastic recoverability following compression, particularly for thin-walled samples with CNTFs still intact. Structural stability to liquid infiltration and drying increased with the number of ALD

  10. Human Cytosolic Extracts Stabilize the HIV-1 Core

    Science.gov (United States)

    Fricke, Thomas; Brandariz-Nuñez, Alberto; Wang, Xiaozhao; Smith, Amos B.

    2013-01-01

    The stability of the HIV-1 core in the cytoplasm is crucial for productive HIV-1 infection. Mutations that stabilize or destabilize the core showed defects on HIV-1 reverse transcription and infection. We developed a novel and simple assay to measure the stability of in vitro-assembled HIV-1 CA-NC complexes. The assay allowed us to demonstrate that cytosolic extracts strongly stabilize the HIV-1 core. Interestingly, stabilization of in vitro-assembled HIV-1 CA-NC complexes is not due solely to macromolecular crowding, suggesting the presence of specific cellular factors that stabilize the HIV-1 core. By using our novel assay, we measured the abilities of different drugs, such as PF74, CAP-1, IXN-053, cyclosporine, Bi2 (also known as BI-2), and the peptide CAI, to modulate the stability of in vitro-assembled HIV-1 CA-NC complexes. Interestingly, we found that PF74 and Bi2 strongly stabilized HIV-1 CA-NC complexes. On the other hand, the peptide CAI destabilized HIV-1 CA-NC complexes. We also found that purified cyclophilin A destabilizes in vitro-assembled HIV-1 CA-NC complexes in the presence of cellular extracts in a cyclosporine-sensitive manner. In agreement with previous observations using the fate-of-the-capsid assay, we also demonstrated the ability of recombinant CPSF6 to stabilize HIV-1 CA-NC complexes. Overall, our findings suggested that cellular extracts specifically stabilize the HIV-1 core. We believe that our assay can be a powerful tool to assess HIV-1 core stability in vitro. PMID:23885082

  11. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  12. Optical Space Telescope Assembly Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Space Telescope Assembly (OSTA) task is to demonstrate the technology readiness of assembling large space telescopes on orbit in 2015. This task is an...

  13. Polystyrene-Core-Silica-Shell Hybrid Particles Containing Gold and Magnetic Nanoparticles.

    Science.gov (United States)

    Tian, Jia; Vana, Philipp

    2016-02-18

    Polystyrene-core-silica-shell hybrid particles were synthesized by combining the self-assembly of nanoparticles and the polymer with a silica coating strategy. The core-shell hybrid particles are composed of gold-nanoparticle-decorated polystyrene (PS-AuNP) colloids as the core and silica particles as the shell. PS-AuNP colloids were generated by the self-assembly of the PS-grafted AuNPs. The silica coating improved the thermal stability and dispersibility of the AuNPs. By removing the "free" PS of the core, hollow particles with a hydrophobic cage having a AuNP corona and an inert silica shell were obtained. Also, Fe3O4 nanoparticles were encapsulated in the core, which resulted in magnetic core-shell hybrid particles by the same strategy. These particles have potential applications in biomolecular separation and high-temperature catalysis and as nanoreactors.

  14. Synthesis of AlNiCo core/shell nanopowders

    Science.gov (United States)

    Genc, A. M.; Akdeniz, M. V.; Ozturk, T.; Kalay, Y. E.

    2016-11-01

    Magnetic core/shell nanostructures have been recently received much interest owing to their utmost potential in permanent magnetic applications. In the present work, AlNiCo permanent magnet powders were synthesized by ball milling and a core/shell nanostructure was obtained using RF induced plasma. The effects of particle size and nanoshell structure on the magnetic properties were investigated in details. The coercivity of AlNiCo powders was found to increase with decreasing particle size, exclusively nanopowders encapsulated with Fe3O4 shell showed the highest coercivity values. The shell structure produced during plasma reaction was found to form a resistant layer against oxidation of metallic nanoparticles.

  15. Histone chaperone-mediated nucleosome assembly process.

    Science.gov (United States)

    Fan, Hsiu-Fang; Liu, Zi-Ning; Chow, Sih-Yao; Lu, Yi-Han; Li, Hsin

    2015-01-01

    A huge amount of information is stored in genomic DNA and this stored information resides inside the nucleus with the aid of chromosomal condensation factors. It has been reported that the repeat nucleosome core particle (NCP) consists of 147-bp of DNA and two copies of H2A, H2B, H3 and H4. Regulation of chromosomal structure is important to many processes inside the cell. In vivo, a group of histone chaperones facilitate and regulate nucleosome assembly. How NCPs are constructed with the aid of histone chaperones remains unclear. In this study, the histone chaperone-mediated nucleosome assembly process was investigated using single-molecule tethered particle motion (TPM) experiments. It was found that Asf1 is able to exert more influence than Nap1 and poly glutamate acid (PGA) on the nucleosome formation process, which highlights Asf1's specific role in tetrasome formation. Thermodynamic parameters supported a model whereby energetically favored nucleosomal complexes compete with non-nucleosomal complexes. In addition, our kinetic findings propose the model that histone chaperones mediate nucleosome assembly along a path that leads to enthalpy-favored products with free histones as reaction substrates.

  16. Fabrication and Testing of Carbon Fiber Reinforced Truss Core Sandwich Panels

    Institute of Scientific and Technical Information of China (English)

    Bing Wang; Linzhi Wu; Li Ma; Qiang Wang; Shanyi Du

    2009-01-01

    Truss core sandwich panels reinforced by carbon fibers were assembled with bonded laminate facesheets and carbon fiber reinforced truss cores. The top and bottom facesheets were interconnected with truss cores. Both ends of the truss cores were embedded into four layers of top and bottom facesheets. The mechanical properties of truss core sandwich panels were then investigated under out-of-plane and in-plane compression loadings to reveal the failure mechanisms of sandwich panels. Experimental results indicated that the mechanical behavior of sandwich structure under in-plane loading is dominated by the buckling and debonding of facesheets.

  17. IGCSE core mathematics

    CERN Document Server

    Wall, Terry

    2013-01-01

    Give your core level students the support and framework they require to get their best grades with this book dedicated to the core level content of the revised syllabus and written specifically to ensure a more appropriate pace. This title has been written for Core content of the revised Cambridge IGCSE Mathematics (0580) syllabus for first teaching from 2013. ? Gives students the practice they require to deepen their understanding through plenty of practice questions. ? Consolidates learning with unique digital resources on the CD, included free with every book. We are working with Cambridge

  18. Core shroud corner joints

    Science.gov (United States)

    Gilmore, Charles B.; Forsyth, David R.

    2013-09-10

    A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.

  19. Development of assembly techniques for fire resistant aircraft interior panels

    Science.gov (United States)

    Lee, S. C. S.

    1978-01-01

    Ten NASA Type A fire resistant aircraft interior panels were fabricated and tested to develop assembly techniques. These techiques were used in the construction of a full scale lavatory test structure for flame propagation testing. The Type A panel is of sandwich construction consisting of Nomex honeycomb filled with quinone dioxime foam, and bismaleimide/glass face sheets bonded to the core with polyimide film adhesive. The materials selected and the assembly techniques developed for the lavatory test structure were designed for obtaining maximum fire containment with minimum smoke and toxic emission.

  20. Assembly language programming ARM Cortex-M3

    CERN Document Server

    Mahout, Vincent

    2013-01-01

    ARM designs the cores of microcontrollers which equip most "embedded systems" based on 32-bit processors. Cortex M3 is one of these designs, recently developed by ARM with microcontroller applications in mind. To conceive a particularly optimized piece of software (as is often the case in the world of embedded systems) it is often necessary to know how to program in an assembly language.This book explains the basics of programming in an assembly language, while being based on the architecture of Cortex M3 in detail and developing many examples.It is written for people who have never pr

  1. Low inductance busbar assembly

    Science.gov (United States)

    Holbrook, Meghan Ann

    2010-09-21

    A busbar assembly for electrically coupling first and second busbars to first and second contacts, respectively, on a power module is provided. The assembly comprises a first terminal integrally formed with the first busbar, a second terminal integrally formed with the second busbar and overlapping the first terminal, a first bridge electrode having a first tab electrically coupled to the first terminal and overlapping the first and second terminals, and a second tab electrically coupled to the first contact, a second bridge electrode having a third tab electrically coupled to the second terminal, and overlapping the first and second terminals and the first tab, and a fourth tab electrically coupled to the second contact, and a fastener configured to couple the first tab to the first terminal, and the third tab to the second terminal.

  2. Plasma chromograninx

    DEFF Research Database (Denmark)

    Goetze, Jens P; Hilsted, Linda M; Rehfeld, Jens F

    2014-01-01

    Cardiovascular risk assessment remains difficult in elderly patients. We examined whether chromogranin A (CgA) measurement in plasma may be valuable in assessing risk of death in elderly patients with symptoms of heart failure in a primary care setting. A total of 470 patients (mean age 73 years......) were followed for 10 years. For CgA plasma measurement, we used a two-step method including a screening test and a confirmative test with plasma pre-treatment with trypsin. Cox multivariable proportional regression and receiver-operating curve (ROC) analyses were used to assess mortality risk...... of follow-up showed significant additive value of CgA confirm measurements compared with NT-proBNP and clinical variables. CgA measurement in the plasma of elderly patients with symptoms of heart failure can identify those at increased risk of short- and long-term mortality....

  3. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  4. LIGHT-WEIGHT LOAD-BEARING STRUCTURES REINFORCED BY CORE ELEMENTS MADE OF SEGMENTS AND A METHOD OF CASTING SUCH STRUCTURES

    DEFF Research Database (Denmark)

    2009-01-01

    The invention relates to a light-weight load-bearing structure, reinforced by core elements (2) of a strong material constituting one or more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2......), where the core (2) is constructed from segments (1) of core elements (2) assembled by means of one or more prestressing elements (4). The invention further relates to a method of casting of light-weight load-bearing structures, reinforced by core elements (2) of a strong material constituting one...... or more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2), where the core (2) is constructed from segments (1) of core elements (2) assembled and hold together by means of one or more prestressing...

  5. LIGHT-WEIGHT LOAD-BEARING STRUCTURES REINFORCED BY CORE ELEMENTS MADE OF SEGMENTS AND A METHOD OF CASTING SUCH STRUCTURES

    DEFF Research Database (Denmark)

    2009-01-01

    The invention relates to a light-weight load-bearing structure, reinforced by core elements (2) of a strong material constituting one or more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2...... or more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2), where the core (2) is constructed from segments (1) of core elements (2) assembled and hold together by means of one or more prestressing......), where the core (2) is constructed from segments (1) of core elements (2) assembled by means of one or more prestressing elements (4). The invention further relates to a method of casting of light-weight load-bearing structures, reinforced by core elements (2) of a strong material constituting one...

  6. Assembly and structure of protein phosphatase 2A

    Institute of Scientific and Technical Information of China (English)

    SHI YiGong

    2009-01-01

    Protein phosphatase 2A (PP2A) represents a conserved family of important protein serinetthreonine phosphatases in species ranging from yeast to human. The PP2A core enzyme comprises a scaffold subunit and a catalytic subunit. The heterotrimeric PP2A holoenzyme consists of the core enzyme and a variable regulatory subunit. The catalytic subunit of PP2A is subject to reversible methylation, mediated by two conserved enzymes. Both the PP2A core and holoenzymes are regulated through interaction with a large number of cellular cofactors. Recent biochemical and structural investigation reveals critical insights into the assembly and function of the PP2A core enzyme as well as two families of holoenzyme. This review focuses on the molecular mechanisms revealed by these latest advances.

  7. Assembly and structure of protein phosphatase 2A

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Protein phosphatase 2A (PP2A) represents a conserved family of important protein serine/threonine phosphatases in species ranging from yeast to human. The PP2A core enzyme comprises a scaffold subunit and a catalytic subunit. The heterotrimeric PP2A holoenzyme consists of the core enzyme and a variable regulatory subunit. The catalytic subunit of PP2A is subject to reversible methylation, medi-ated by two conserved enzymes. Both the PP2A core and holoenzymes are regulated through interac-tion with a large number of cellular cofactors. Recent biochemical and structural investigation reveals critical insights into the assembly and function of the PP2A core enzyme as well as two families of holoenzyme. This review focuses on the molecular mechanisms revealed by these latest advances.

  8. Composite airfoil assembly

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Crespo, Andres Jose

    2015-03-03

    A composite blade assembly for mounting on a turbine wheel includes a ceramic airfoil and an airfoil platform. The ceramic airfoil is formed with an airfoil portion, a blade shank portion and a blade dovetail tang. The metal platform includes a platform shank and a radially inner platform dovetail. The ceramic airfoil is captured within the metal platform, such that in use, the ceramic airfoil is held within the turbine wheel independent of the metal platform.

  9. Plasma confinement

    CERN Document Server

    Hazeltine, R D

    2003-01-01

    Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

  10. SCT Barrel Assembly Complete

    CERN Multimedia

    L. Batchelor

    As reported in the April 2005 issue of the ATLAS eNews, the first of the four Semiconductor Tracker (SCT) barrels, complete with modules and services, arrived safely at CERN in January of 2005. In the months since January, the other three completed barrels arrived as well, and integration of the four barrels into the entire barrel assembly commenced at CERN, in the SR1 building on the ATLAS experimental site, in July. Assembly was completed on schedule in September, with the addition of the innermost layer to the 4-barrel assembly. Work is now underway to seal the barrel thermal enclosure. This is necessary in order to enclose the silicon tracker in a nitrogen atmosphere and provide it with faraday-cage protection, and is a delicate and complicated task: 352 silicon module powertapes, 352 readout-fibre bundles, and over 400 Detector Control System sensors must be carefully sealed into the thermal enclosure bulkhead. The team is currently verifying the integrity of the low mass cooling system, which must be d...

  11. Ordinary General Assembly

    CERN Multimedia

    Association du personnel

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Modifications to the statutes of the association Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda...

  12. OH Module Assembly Stand

    Energy Technology Data Exchange (ETDEWEB)

    Bolan, P.J.; /Fermilab

    1990-10-16

    There is an OR module assembly stand in use at IB4. This design has been approved by safety, as presented by Mike Foley, and has been successfully used. Another one is needed at the D-zero assembly building, but some modifications need to be made. This report will show that the new modified design is at least as strong, if not stronger, than the older IB4 design in every aspect. Since the weight distribution of the OR modules on the sling is indeterminate, this report compares three cases of support for the entire assembly: the lowest two beams only, the lowest four beams only, and all six beams. In each of these cases, the new design is stronger than the old design in maximum allowable weight. The ability of the the cradle to support the weight is also shown. For all of the failure conditions except for two, the cradle is stronger than the beams that it supports. In the two excepted situations, the calculated limit of the cradle is less than the beams it supports. This is because no credit is taken for the sling and strongback, which in reality will relieve much of the horizontal load.

  13. IAHS Third Scientific Assembly

    Science.gov (United States)

    The International Association of Hydrological Sciences (IAHS) convened its Third Scientific Assembly in Baltimore, Md., May 10-19, 1989. The Assembly was attended by about 450 scientists and engineers. The attendance was highest from the U.S., as could be expected; 37 were from Canada; 22 each, Netherlands and United Kingdom; 14, Italy; 12, China; 10, Federal Republic of Germany; 8 each from France, the Republic of South Africa, and Switzerland; 7, Austria; 6 each, Finland and Japan; others were scattered among the remainder of 48 countries total.one of the cosponsors and also handled business matters for the Assembly. Other cosponsors included the International Association of Meteorology and Atmospheric Physics (IAMAP), United Nations Environmental Program (UNEP), United Nations Educational, Scientific, and Cultural Organization (UNESCO), World Meteorological Organization (WMO), and U.K. Overseas Development Authority (ODA). U.S. federal agencies serving as cosponsors included the Environmental Protection Agency, National Aeronautics and Space Administration, National Science Foundation, National Weather Service, Department of Agriculture, Department of State, and U.S. Geological Survey.

  14. Fourth Doctoral Student Assembly

    CERN Multimedia

    Ingrid Haug

    2016-01-01

    On 10 May, over 130 PhD students and their supervisors, from both CERN and partner universities, gathered for the 4th Doctoral Student Assembly in the Council Chamber.   The assembly was followed by a poster session, at which eighteen doctoral students presented the outcome of their scientific work. The CERN Doctoral Student Programme currently hosts just over 200 students in applied physics, engineering, computing and science communication/education. The programme has been in place since 1985. It enables students to do their research at CERN for a maximum of three years and to work on a PhD thesis, which they defend at their University. The programme is steered by the TSC committee, which holds two selection committees per year, in June and December. The Doctoral Student Assembly was opened by the Director-General, Fabiola Gianotti, who stressed the importance of the programme in the scientific environment at CERN, emphasising that there is no more rewarding activity than lear...

  15. A consensus approach to vertebrate de novo transcriptome assembly from RNA-seq data: Assembly of the duck (Anas platyrhynchos transcriptome.

    Directory of Open Access Journals (Sweden)

    Joanna eMoreton

    2014-06-01

    Full Text Available For vertebrate organisms where a reference genome is not available, de novo transcriptome assembly enables a cost effective insight into the identification of tissue specific or differentially expressed genes and variation of the coding part of the genome. However, since there are a number of different tools and parameters that can be used to reconstruct transcripts, it is difficult to determine an optimal method. Here we suggest a pipeline based on (1 assessing the performance of three different assembly tools (2 using both single and multiple k-mer approaches (3 examining the influence of the number of reads used in the assembly (4 merging assemblies from different tools. We use an example dataset from the vertebrate Anas platyrhynchos domestica (Pekin duck. We find that taking a subset of data enables a robust assembly to be produced by multiple methods without the need for very high memory capacity. The use of reads mapped back to transcripts (RMBT and CEGMA (Core Eukaryotic Genes Mapping Approach provides useful metrics to determine the completeness of assembly obtained. For this dataset the use of multiple k-mers in the assembly generated a more complete assembly as measured by greater number of RMBT and CEGMA score. Merged single k-mer assemblies are generally smaller but consist of longer transcripts, suggesting an assembly consisting of fewer fragmented transcripts. We suggest that the use of a subset of reads during assembly allows the relatively rapid investigation of assembly characteristics and can guide the user to the most appropriate transcriptome for particular downstream use. Transcriptomes generated by the compared assembly methods and the final merged assembly are freely available for download at http://dx.doi.org/10.6084/m9.figshare.1032613.

  16. Conceptual design of ASTRID fuel sub-assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Thierry, E-mail: thierry.beck@cea.fr [CEA Cadarache, DEN, DEC, F-13108 Saint-Paul-lez-Durance (France); Blanc, Victor; Escleine, Jean-Michel [CEA Cadarache, DEN, DEC, F-13108 Saint-Paul-lez-Durance (France); Haubensack, David [CEA Cadarache, DEN, DER, F-13108 Saint-Paul-lez-Durance (France); Pelletier, Michel; Phelip, Mayeul [CEA Cadarache, DEN, DEC, F-13108 Saint-Paul-lez-Durance (France); Perrin, Benoît [AREVA-NP, 10 rue J. Récamier, 69456 Lyon Cedex 06 (France); Venard, Christophe [CEA Cadarache, DEN, DER, F-13108 Saint-Paul-lez-Durance (France)

    2017-04-15

    Highlights: • The fuel sub-assembly design for the ASTRID CFV core is described. • Innovative design choices have been made to comply with the GEN IV objectives. • The heterogeneous and the large fuel pins contribute to a low sodium void worth. • The upper neutron shielding is removable from the S/A head before washing. - Abstract: The French 600 MWe Advanced Sodium Technological Reactor for Industrial Demonstration (ASTRID) project has reached the end of its Conceptual Design phase. The core design studies are being conducted by the CEA with support from AREVA and EDF. Innovative design choices for the core have been made to comply with the GEN IV reactor objectives, marking a break with the former Phénix and SuperPhénix Sodium Fast Reactors. The main objective to improve safety compared with current GEN II or III reactors led to a core design that demonstrates intrinsically safe behaviour. A negative sodium void worth is achieved thanks to a new fuel sub-assembly design including (U,Pu)O{sub 2} and UO{sub 2} axially heterogeneous fuel pins, a large cladding/small spacer wire bundle, a sodium plenum above the fuel pins, and upper neutron shielding with both enriched and natural boron carbide (B{sub 4}C) which also maintain a low secondary sodium activity level. As these Na-bonded B{sub 4}C pins can lead to the retention of unacceptable amounts of sodium, the whole upper neutron shielding has been made removable on-line through the sub-assembly head just before the washing operations. Finite elements calculations have been performed to increase the stiffness of the stamped spacer pads in order to analyse its effect on the core mechanical behaviour during hypothetical radial core flowering and compaction events. More generally, all design choices for ASTRID have been made with the permanent objective of minimising the sub-assembly height to decrease the overall costs of the reactor and the fuel cycle. This paper describes the fuel sub-assembly design for

  17. Solid charged-core model of ball lightning

    Directory of Open Access Journals (Sweden)

    D. B. Muldrew

    2010-01-01

    Full Text Available In this study, ball lightning (BL is assumed to have a solid, positively-charged core. According to this underlying assumption, the core is surrounded by a thin electron layer with a charge nearly equal in magnitude to that of the core. A vacuum exists between the core and the electron layer containing an intense electromagnetic (EM field which is reflected and guided by the electron layer. The microwave EM field applies a ponderomotive force (radiation pressure to the electrons preventing them from falling into the core. The energetic electrons ionize the air next to the electron layer forming a neutral plasma layer. The electric-field distributions and their associated frequencies in the ball are determined by applying boundary conditions to a differential equation given by Stratton (1941. It is then shown that the electron and plasma layers are sufficiently thick and dense to completely trap and guide the EM field. This model of BL is exceptional in that it can explain all or nearly all of the peculiar characteristics of BL. The ES energy associated with the core charge can be extremely large which can explain the observations that occasionally BL contains enormous energy. The mass of the core prevents the BL from rising like a helium-filled balloon – a problem with most plasma and burning-gas models. The positively charged core keeps the negatively charged electron layer from diffusing away, i.e. it holds the ball together; other models do not have a mechanism to do this. The high electrical charges on the core and in the electron layer explains why some people have been electrocuted by BL. Experiments indicate that BL radiates microwaves upon exploding and this is consistent with the model. The fact that this novel model of BL can explain these and other observations is strong evidence that the model should be taken seriously.

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    Science.gov (United States)

    The Cancer Genome Atlas (TCGA) Biospecimen Core Resource centralized laboratory reviews and processes blood and tissue samples and their associated data using optimized standard operating procedures for the entire TCGA Research Network.

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    Data.gov (United States)

    Federal Laboratory Consortium — The core[HTML_REMOVED]s goal is to help researchers of any expertise perform zebrafish experiments aimed at illuminating basic biology and human disease mechanisms,...

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    Data.gov (United States)

    Federal Laboratory Consortium — The induced Pluripotent Stem Cells (iPSC) Core was created in 2011 to accelerate stem cell research in the NHLBI by providing investigators consultation, technical...