Sample records for xt-ads core design

  1. Air core pulse transformer design

    Microsoft Academic Search

    J. P. O'Loughlin; J. D. Sidler; Gerry J. Rohwein

    1988-01-01

    Cylindrical-air-core pulse transformers capable of passing high-voltage\\/high-energy pulse waveforms with high efficiency and low distortion require a much more delicate design balance of physical dimensions and electrical parameters than iron or ferrite core units. Special computer codes were written to evaluate their performance. The analysis includes calculation of the self and mutual inductances as determined by the dimensions and insulation

  2. Air core pulse transformer design

    SciTech Connect

    O'Loughlin, J.P.; Sidler, J.D.; Rohwein, G.J.

    1988-01-01

    Cylindrical air core pulse transformers capable of passing high voltage/energy pulse waveforms with high efficiency and low distortion require a much more delicate design balance of physical dimensions and electrical parameters that iron or ferrite core units. The two salient advantages of the air core transformer are a much lighter weight and a simplified high voltage insulation system. Special computer codes were written to evaluate the performance. The analysis includes calculation of the self and mutual inductances as determined by the dimensions and insulation stress, evaluation of the waveforms distortion and energy transfer efficiency. Graphical data are given for the optimization in terms of electrical parameters. The results are in agreement with experimental data. It is concluded that air core transformers are feasible operating at hundreds of kilovolts and lens of kioljoules in the microsecond region with energy transfer efficiencies of 70% to 85%. The insulation stresses required are in the 100 to 300 kV/em range. Effects of the high frequency current distribution in the windings and the use of ''slug'' type ferrite cores are also evaluated.

  3. Air core pulse transformer design

    NASA Astrophysics Data System (ADS)

    Oloughlin, J. P.; Sidler, J. D.; Rohwein, G. J.

    Cylindrical air core pulse transformers capable of passing high voltage/energy pulse waveforms with high efficiency and low distortion require a much more delicate design balance of physical dimensions and electrical parameters that iron or ferrite core units. The two salient advantages of the air core transformer are a much lighter weight and a simplified high voltage insulation system. Special computer codes were written to evaluate the performance. The analysis includes calculation of the self and mutual inductances as determined by the dimensions and insulation stress, evaluation of the waveforms distortion and energy transfer efficiency. Graphical data are given for the optimization in terms of electrical parameters. The results are in agreement with experimental data. It is concluded that air core transformers are feasible operating at hundreds of kilovolts and tens of kioljoules in the microsecond region with energy transfer efficiencies of 70 to 85 percent. The insulation stresses required are in the 100 to 300 kV/em range. Effects of the high frequency current distribution in the windings and the use of slug type ferrite cores are also evaluated.

  4. Design configuration of GCFR core assemblies

    SciTech Connect

    LaBar, M.P.; Lee, G.E.; Meyer, R.J.

    1980-05-01

    The current design configurations of the core assemblies for the gas-cooled fast reactor (GCFR) demonstration plant reactor core conceptual design are described. Primary emphasis is placed upon the design innovations that have been incorporated in the design of the core assemblies since the establishment of the initial design of an upflow GCFR core. A major feature of the design configurations is that they are prototypical of core assemblies for use in commercial plants; a larger number of the same assemblies would be used in a commercial plant.

  5. GCFR core thermal-hydralic design

    SciTech Connect

    Schleuter, G.; Baxi, C.B.; Bennett, F.O.

    1980-05-01

    The approach for developing the thermal-hydraulic core assembly designs for the gas-cooled fast reactor (GCFR) is reviewed, and key considerations for improving the core performance at all power and flow conditions are discussed. It is shown how the thermal-hydraulic core assembly designs evolve from evaluations of plant size, material limitations, safety criteria, and structural performance considerations.

  6. Calculation of core loss in a novel transformer design

    Microsoft Academic Search

    W. L. Collett; H. R. Buswell

    2011-01-01

    Recent efforts to develop a new power transformer incorporating a novel wire core configuration have required that core magnetic flux and power loss be estimated during the development process. In this work, an innovative core concept was considered using commercial finite element simulation software, with core loss results shown to be comparable to measurements on a standard 10 kVA design.

  7. Energy Efficient Engine core design and performance report

    NASA Technical Reports Server (NTRS)

    Stearns, E. Marshall

    1982-01-01

    The Energy Efficient Engine (E3) is a NASA program to develop fuel saving technology for future large transport aircraft engines. Testing of the General Electric E3 core showed that the core component performance and core system performance necessary to meet the program goals can be achieved. The E3 core design and test results are described.

  8. Novel design of foam core junctions in sandwich panels

    Microsoft Academic Search

    E. Bozhevolnaya; A. Lyckegaard; O. T. Thomsen

    2008-01-01

    An improved design of core junctions in sandwich panels\\/beams is proposed. The improved\\/novel design consists of a specific geometrical shaping of the boundary of the adjoined core materials, which substantially diminishes the local stress concentrations at core junctions subjected to transverse shear loading. Two groups of the beams with conventional butt junctions and modified (spline shaped) junctions are manufactured and

  9. Learn from the Core--Design from the Core

    ERIC Educational Resources Information Center

    Ockerse, Thomas

    2012-01-01

    The current objective, object-oriented approach to design is questioned along with design education viewed as a job-oriented endeavor. Instead relational knowledge and experience in a holistic sense, both tacit and explicit, are valued along with an appreciation of the unique character of the student. A new paradigm for design education is…

  10. Design and Test of Processor-Core Based Systems

    Microsoft Academic Search

    Peter Marwedel

    1997-01-01

    This tutorial responds to the rapidly increasing use of various cores for implementing systems-on-a-chip. It specific- ally focusses on processor cores. We will give some examples of cores, including DSP cores and application-specific instruction- set processors (ASIPs). We will mention market trends for these components, and we will touch design procedures, in particular the use compilers. Finally, we will discuss

  11. An open core rotator design methodology

    Microsoft Academic Search

    J. A. Kirk; G. E. Sullivan; L. P. Hromada

    1997-01-01

    In low earth orbit [LEO] satellite applications, spacecraft power is provided by photovoltaic cells and batteries. To overcome battery shortcomings, FARE, Inc., working in cooperation with the University of Maryland [UOM] and the NASA Lewis Research Center, has developed an open core magnetically-suspended graphite-epoxy flywheel for energy storage applications. This flywheel energy storage system, called the Open Core Rotator [OCR],

  12. Advanced neutron source final preconceptual reference core design

    Microsoft Academic Search

    G. L. Copeland; W. R. Gambill; R. M. Harrington; J. A. Johnson; F. J. Peretz; H. Reutler; J. M. Ryskamp; D. L. Selby; C. D. West; G. L. Yoder

    1989-01-01

    The preconceptual design phase of the Advanced Neutron Source (ANS) Project ended with the selection of a reference reactor core that will be used to begin conceptual design work. The new reference core consists of two involute fuel elements, of different diameters, aligned axially with a small axial gap between them. The use of different element diameters permits a separate

  13. Pre-conceptual design study of ASTRID core

    SciTech Connect

    Varaine, F.; Marsault, P.; Chenaud, M. S.; Bernardin, B.; Conti, A.; Sciora, P.; Venard, C.; Fontaine, B.; Devictor, N.; Martin, L. [Alternative Energies and Atomic Energy Commission, CEA, DEN DER, 13108 St Paul lez Durance (France); Scholer, A. C.; Verrier, D. [AREVA-NP, 10 rue J. Recamier, 69456 Lyon Cedex 06 (France)

    2012-07-01

    In the framework of the ASTRID project at CEA, core design studies are performed at CEA with the AREVA and EDF support. At the stage of the project, pre-conceptual design studies are conducted in accordance with GEN IV reactors criteria, in particularly for safety improvements. An improved safety for a sodium cooled reactor requires revisiting many aspects of the design and is a rather lengthy process in current design approach. Two types of cores are under evaluation, one classical derived from the SFR V2B and one more challenging called CFV (low void effect core) with a large gain on the sodium void effect. The SFR V2b core have the following specifications: a very low burn-up reactivity swing (due to a small cycle reactivity loss) and a reduced sodium void effect with regard to past designs such as the EFR (around 2$ minus). Its performances are an average burn-up of 100 GWd/t, and an internal conversion ratio equal to one given a very good behavior of this core during a control rod withdrawal transient). The CFV with its specific design offers a negative sodium void worth while maintaining core performances. In accordance of ASTRID needs for demonstration those cores are 1500 MWth power (600 MWe). This paper will focus on the CFV pre-conceptual design of the core and S/A, and the performances in terms of safety will be evaluated on different transient scenario like ULOF, in order to assess its intrinsic behavior compared to a more classical design like V2B core. The gap in term of margin to a severe accident due to a loss of flow initiator underlines the potential capability of this type of core to enhance prevention of severe accident in accordance to safety demonstration. (authors)

  14. On design of air-core Ethernet transformers

    NASA Astrophysics Data System (ADS)

    Bowen, D.; Mayergoyz, I.; Krafft, C.; Kroop, D.; Beyaz, M.

    2009-04-01

    The air-core designs of Ethernet transformers in which the reduction of winding magnetic coupling is compensated by increasing the cross-winding capacitance coupling are discussed. The theoretical analysis that accounts for the distributed nature of the cross-winding capacitance is presented. It is demonstrated that the capacitive cross-winding coupling may result in desirable transfer characteristics of air-core transformers that are similar to those of ferrite core Ethernet transformers.

  15. Preliminary engineering design of sodium-cooled CANDLE core

    NASA Astrophysics Data System (ADS)

    Takaki, Naoyuki; Namekawa, Azuma; Yoda, Tomoyuki; Mizutani, Akihiko; Sekimoto, Hiroshi

    2012-06-01

    The CANDLE burning process is characterized by the autonomous shifting of burning region with constant reactivity and constant spacial power distribution. Evaluations of such critical burning process by using widely used neutron diffusion and burning codes under some realistic engineering constraints are valuable to confirm the technical feasibility of the CANDLE concept and to put the idea into concrete core design. In the first part of this paper, it is discussed that whether the sustainable and stable CANDLE burning process can be reproduced even by using conventional core analysis tools such as SLAROM and CITATION-FBR. As a result, it is certainly possible to demonstrate it if the proper core configuration and initial fuel composition required as CANDLE core are applied to the analysis. In the latter part, an example of a concrete image of sodium cooled, metal fuel, 2000MWt rating CANDLE core has been presented by assuming an emerging inevitable technology of recladding. The core satisfies engineering design criteria including cladding temperature, pressure drop, linear heat rate, and cumulative damage fraction (CDF) of cladding, fast neutron fluence and sodium void reactivity which are defined in the Japanese FBR design project. It can be concluded that it is feasible to design CADLE core by using conventional codes while satisfying some realistic engineering design constraints assuming that recladding at certain time interval is technically feasible.

  16. Designing systems-on-chip using cores

    Microsoft Academic Search

    Reinaldo A. Bergamaschi; William R. Lee

    2000-01-01

    Leading-edge systems-on-chip (SoC) being designed today could reach 20 Million gates and 0.5 to 1 GHz operating frequency. In order to implement such systems, designers are increasingly relying on reuse of Intellectual property (IP) blocks. Since IP blocks are pre-designed and pre-verified, the designer can concentrate on the complete system without having to worry about the correctness or performance of

  17. Sifting through the many-core design space

    E-print Network

    Mullins, Robert

    Sifting through the many-core design space Robert Mullins Computer Laboratory, University #12;A new design space · Much larger set of viable designs ­ More than a single pipeline to optimise · Disparate architectures ­ Beyond differences in simple parameters · Can't build a simple parameterised model

  18. Fuel and Core Design Experiences in Cofrentes NPP

    SciTech Connect

    Garcia-Delgado, L.; Lopez-Carbonell, M.T.; Gomez-Bernal, I. [Iberdrola Generacion, Nuclear Fuel Department, Hermosilla 3, 28001 Madrid (Spain)

    2002-07-01

    The electricity market deregulation in Spain is increasing the need for innovations in nuclear power generation, which can be achieved in the fuel area by improving fuel and core designs and by introducing vendors competition. Iberdrola has developed the GIRALDA methodology for design and licensing of Cofrentes reloads, and has introduced mixed cores with fuel from different vendors. The application of GIRALDA is giving satisfactory results, and is showing its capability to adequately reproduce the core behaviour. The nuclear design team is acquiring an invaluable experience and a deep knowledge of the core, very useful to support cycle operation. Continuous improvements are expected for the future in design strategies as well as in the application of new technologies to redesign the methodology processes. (authors)

  19. VCDS: virtual core based design system

    Microsoft Academic Search

    M. Muraoka

    1999-01-01

    The Design Productivity Crisis of LSI towards 2010 have been discussed for a few years especially in SEMATECH, USA. The innovation of LSI design methodology will be the most effective way to resolve the issues of the design crisis. SIRIJ, Semiconductor Industry Research Institute Japan, has organized `VCDS Committee' to research the next generation EDA system towards 2010. `VCDS: Virtual

  20. Verifying IP-core based system-on-chip designs

    Microsoft Academic Search

    Pankaj Chauhan; Edmund M. Clarke; Yuan Lu; Dong Wang

    1999-01-01

    We describe a methodology for verifying system-on-chip designs. In our methodology, the problem of verifying system-on-chip designs is decomposed into three tasks. First, we verify, once and for all, the standard bus interconnecting IP cores in the system. The next task is to verify the glue logic, which connects the IP cores to the buses. Finally, using the verified bus

  1. De novo design of the hydrophobic core of ubiquitin.

    PubMed Central

    Lazar, G. A.; Desjarlais, J. R.; Handel, T. M.

    1997-01-01

    We have previously reported the development and evaluation of a computational program to assist in the design of hydrophobic cores of proteins. In an effort to investigate the role of core packing in protein structure, we have used this program, referred to as Repacking of Cores (ROC), to design several variants of the protein ubiquitin. Nine ubiquitin variants containing from three to eight hydrophobic core mutations were constructed, purified, and characterized in terms of their stability and their ability to adopt a uniquely folded native-like conformation. In general, designed ubiquitin variants are more stable than control variants in which the hydrophobic core was chosen randomly. However, in contrast to previous results with 434 cro, all designs are destabilized relative to the wild-type (WT) protein. This raises the possibility that beta-sheet structures have more stringent packing requirements than alpha-helical proteins. A more striking observation is that all variants, including random controls, adopt fairly well-defined conformations, regardless of their stability. This result supports conclusions from the cro studies that non-core residues contribute significantly to the conformational uniqueness of these proteins while core packing largely affects protein stability and has less impact on the nature or uniqueness of the fold. Concurrent with the above work, we used stability data on the nine ubiquitin variants to evaluate and improve the predictive ability of our core packing algorithm. Additional versions of the program were generated that differ in potential function parameters and sampling of side chain conformers. Reasonable correlations between experimental and predicted stabilities suggest the program will be useful in future studies to design variants with stabilities closer to that of the native protein. Taken together, the present study provides further clarification of the role of specific packing interactions in protein structure and stability, and demonstrates the benefit of using systematic computational methods to predict core packing arrangements for the design of proteins. PMID:9194177

  2. Automated Design and Optimization of Pebble-bed Reactor Cores

    SciTech Connect

    Hans D. Gougar; Abderrafi M. Ougouag; William K. Terry

    2010-07-01

    We present a conceptual design approach for high-temperature gas-cooled reactors using recirculating pebble-bed cores. The design approach employs PEBBED, a reactor physics code specifically designed to solve for and analyze the asymptotic burnup state of pebble-bed reactors, in conjunction with a genetic algorithm to obtain a core that maximizes a fitness value that is a function of user-specified parameters. The uniqueness of the asymptotic core state and the small number of independent parameters that define it suggest that core geometry and fuel cycle can be efficiently optimized toward a specified objective. PEBBED exploits a novel representation of the distribution of pebbles that enables efficient coupling of the burnup and neutron diffusion solvers. With this method, even complex pebble recirculation schemes can be expressed in terms of a few parameters that are amenable to modern optimization techniques. With PEBBED, the user chooses the type and range of core physics parameters that represent the design space. A set of traits, each with acceptable and preferred values expressed by a simple fitness function, is used to evaluate the candidate reactor cores. The stochastic search algorithm automatically drives the generation of core parameters toward the optimal core as defined by the user. The optimized design can then be modeled and analyzed in greater detail using higher resolution and more computationally demanding tools to confirm the desired characteristics. For this study, the design of pebble-bed high temperature reactor concepts subjected to demanding physical constraints demonstrated the efficacy of the PEBBED algorithm.

  3. Automatic Design of Area-Efficient Configurable ASIC Cores

    E-print Network

    Compton, Katherine

    Automatic Design of Area-Efficient Configurable ASIC Cores Katherine Compton University for a given computation domain, we explore the design space between an ASIC and an FPGA. However, the manual to given application sets. This article discusses configurable ASIC (cASIC) architecture generation

  4. Design of Reliable Metro Core Networks

    Microsoft Academic Search

    P. Castoldi; F. Cugini; P. Ghelfil; L. Valcarenghil; G. Franzl; P. Gravey; M. Morvan; L. Rea; F. Matera; K. Wajda

    2007-01-01

    In this study the design of reliable network topologies is applied to a typical metro network scenario. Results show that, with an increasing amount of traffic, ring topologies represent a less attractive solution and, on the other hand, highly connected DWDM mesh networks are required to grant the required level of throughput for bandwidth demanding applications and services.

  5. A Tight Lattice, Epithermal Core Design for the Integral PWR

    SciTech Connect

    Saccheri, J.G.B. [Brookhaven National Laboratory, Nuclear Science and Technology Division Bldg 475, Upton, New York 11973-5000 (United States); Todreas, N.E.; Driscoll, M.J. [Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Bldg. 24-205 MA 02139-4307 (United States)

    2004-07-01

    An 8-year core design for an epithermal, water-cooled reactor has been developed based upon assessments of nuclear reactor physics, thermal-hydraulics and economics. An integral vessel configuration is adopted and self-supporting wire-wrap fuel is employed for the tight lattice of the epithermal core. A streaming path is incorporated in each assembly to ensure a negative void coefficient. A whole-core MCNP simulation of the tight core shows a negative void coefficient for any burnup with positive K{sub EFF}. The VIPRE{sup TM} code has been used to calculate the critical heat flux (CHF) by means of an appropriate wire-wrap CHF correlation, specifically introduced in the source code. Economically, the high fuel enrichment (14% w/o {sup 235}U) and the very long core life (8 ys) lead to high lifetime-levelized unit fuel cycle cost (in mills/kWhre). However, both operation and maintenance and capital-related expenditures strongly benefited from the higher electric output per unit volume, which yielded quite small lifetime-levelized unit capital and operation and maintenance costs for the overall plant. Financing costs are included and an estimate is provided for the total lifetime-levelized unit cost of the epithermal core, which is about 20% lower than that of a more open lattice thermal spectrum core fitting into the same core envelope and with 4-year lifetime. (authors)

  6. Current advances in precious metal core-shell catalyst design

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohong; He, Beibei; Hu, Zhiyu; Zeng, Zhigang; Han, Sheng

    2014-08-01

    Precious metal nanoparticles are commonly used as the main active components of various catalysts. Given their high cost, limited quantity, and easy loss of catalytic activity under severe conditions, precious metals should be used in catalysts at low volumes and be protected from damaging environments. Accordingly, reducing the amount of precious metals without compromising their catalytic performance is difficult, particularly under challenging conditions. As multifunctional materials, core-shell nanoparticles are highly important owing to their wide range of applications in chemistry, physics, biology, and environmental areas. Compared with their single-component counterparts and other composites, core-shell nanoparticles offer a new active interface and a potential synergistic effect between the core and shell, making these materials highly attractive in catalytic application. On one hand, when a precious metal is used as the shell material, the catalytic activity can be greatly improved because of the increased surface area and the closed interfacial interaction between the core and the shell. On the other hand, when a precious metal is applied as the core material, the catalytic stability can be remarkably improved because of the protection conferred by the shell material. Therefore, a reasonable design of the core-shell catalyst for target applications must be developed. We summarize the latest advances in the fabrications, properties, and applications of core-shell nanoparticles in this paper. The current research trends of these core-shell catalysts are also highlighted.

  7. Core design of the upgraded TREAT reactor

    Microsoft Academic Search

    D. C. Wade; S. K. Bhattacharyya; W. C. Lipinski; C. C. Stone

    1982-01-01

    The upgrading of the TREAT reactor involves the replacement of the central 11 x 11 subzone of the 19 x 19 fuel assembly array by new, Inconel-clad, high-temperature fuel assemblies, and the additions of a new reactor control system, a safety-grade plant protection system, and an enhanced reactor filtration\\/coolant system. The final design of these modifications will be completed in

  8. Core design of the upgraded TREAT reactor

    SciTech Connect

    Wade, D.C.; Bhattacharyya, S.K.; Lipinski, W.C.; Stone, C.C.

    1982-01-01

    The upgrading of the TREAT reactor involves the replacement of the central 11 x 11 subzone of the 19 x 19 fuel assembly array by new, Inconel-clad, high-temperature fuel assemblies, and the additions of a new reactor control system, a safety-grade plant protection system, and an enhanced reactor filtration/coolant system. The final design of these modifications will be completed in early 1983. The TREAT facility is scheduled to be shut down for modification in mid-1984, and should resume the safety test program in mid-1985. The upgrading will provide a capability to conduct fast reactor safety tests on clusters of up to 37 prototypic LMFBR pins.

  9. Influence Of Low Boron Core Design On PWR Transient Behavior

    SciTech Connect

    Aleksandrov Papukchiev, Angel; Yubo Liu [Technical University Munich, Arcisstrasse 21, 80333 Muenchen (Germany); Schaefer, Anselm [ISaR Institute for Safety and Reliability, Walther-Meissner-Str. 2 85748 Garching (Germany)

    2006-07-01

    In conventional pressurized water reactor (PWR) designs, the concentration of boron in primary coolant is limited by the requirement of having a negative moderator density coefficient. As high boron concentrations have significant impact on reactivity feedback properties, design changes to reduce boron concentration in the reactor coolant are of general interest in view of improving PWR inherent safety. In the framework of an investigation into the feasibility of low boron design, a PWR core configuration based on fuel with higher gadolinium (Gd) content has been developed which permits to reduce the natural boron concentration at begin of cycle (BOC) by approx. 50% compared to current German PWR technology. For the assessment of the potential safety advantages, a Loss-of-Feedwater Anticipated Transient Without Scram (ATWS LOFW) has been simulated with the system code ATHLET for two PWR core designs: a low boron design and a standard core design. The most significant difference in the transient performance of both designs is the total primary fluid mass released through the pressurizer (PRZ) valves. It is reduced by a factor of four for the low boron reactor, indicating its improved density reactivity feedback. (authors)

  10. Implementation of an Arm Compatible Processor Core for SOC Designs

    Microsoft Academic Search

    Ahmed A. Morgan; M. E. Allam; M. A. Salama; H. A. K. Mansour

    2005-01-01

    Hardware description languages (HDLs) are commonly used to construct hardware systems. Reuse of the design is a common practice to improve the productivity nowadays. In this paper, an implementation of a fully pipelined ARM compatible processor core, which can be embedded into system-on-chips (SOCs) is presented. The implementation aims to support research, education, and development by opening the source codes.

  11. Two stochastic optimization algorithms applied to nuclear reactor core design

    Microsoft Academic Search

    Wagner F. Sacco; Cassiano R. E. de oliveira; Cláudio M. N. A. Pereira

    2006-01-01

    Two stochastic optimization algorithms conceptually similar to Simulated Annealing are presented and applied to a core design optimization problem previously solved with Genetic Algorithms. The two algorithms are the novel Particle Collision Algorithm (PCA), which is introduced in detail, and Dueck's Great Deluge Algorithm (GDA). The optimization problem consists in adjusting several reactor cell parameters, such as dimensions, enrichment and

  12. Shield Design for a Space Based Vapor Core Reactor

    SciTech Connect

    Knight, Travis; Anghaie, Samim [Innovative Nuclear Space Power and Propulsion Institute (INSPI), PO Box 116502, University of Florida, Gainesville, FL 32611-6502 (United States)

    2002-07-01

    Innovative shielding strategies were sought to reduce the mass of the required shielding for a space based vapor core reactor system with magnetohydrodynamic energy conversion. Gamma-rays directly resultant from fission were found to play no role in the dose rate, while secondary gamma-rays from fission neutron interactions were the dominant contributor to the dose rate. Hydrogen containing materials such as polyethylene were utilized to provide shielding of both radiation from the reactor complex and also solar and galactic cosmic radiation. This shield design was found to contribute 0.125 kg/kWe to the baseline vapor core reactor system specific mass. (authors)

  13. AIR-CORE FOIL-WOUND PULSE TRANSFORMER DESIGN CONCEPT

    Microsoft Academic Search

    K. A. Khan; R. G. Colclaser

    1993-01-01

    A high voltage output pulse can be provided by a pulse forming network (PFN) using a pulse transformer (IT) as the last output stage. The parameter values of the PFN\\/PT combination are constrained by the output pulse duration, rise time, and load impedance. An air-core foil-wound transformer design offers the advantages of light weight and quasi-uniform voltage distribution between windings,

  14. Hyper-heuristic applied to nuclear reactor core design

    NASA Astrophysics Data System (ADS)

    Domingos, R. P.; Platt, G. M.

    2013-02-01

    The design of nuclear reactors gives rises to a series of optimization problems because of the need for high efficiency, availability and maintenance of security levels. Gradient-based techniques and linear programming have been applied, as well as genetic algorithms and particle swarm optimization. The nonlinearity, multimodality and lack of knowledge about the problem domain makes de choice of suitable meta-heuristic models particularly challenging. In this work we solve the optimization problem of a nuclear reactor core design through the application of an optimal sequence of meta-heuritics created automatically. This combinatorial optimization model is known as hyper-heuristic.

  15. Preliminary design study of advanced multistage axial flow core compressors

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.; Koch, C. C.; Smith, L. H., Jr.

    1977-01-01

    A preliminary design study was conducted to identify an advanced core compressor for use in new high-bypass-ratio turbofan engines to be introduced into commercial service in the 1980's. An evaluation of anticipated compressor and related component 1985 state-of-the-art technology was conducted. A parametric screening study covering a large number of compressor designs was conducted to determine the influence of the major compressor design features on efficiency, weight, cost, blade life, aircraft direct operating cost, and fuel usage. The trends observed in the parametric screening study were used to develop three high-efficiency, high-economic-payoff compressor designs. These three compressors were studied in greater detail to better evaluate their aerodynamic and mechanical feasibility.

  16. System design description for GCFR-core flow test loop

    SciTech Connect

    Huntley, W.R.; Grindell, A.G.

    1980-12-01

    The Core Flow Test Loop is a high-pressure, high-temperature, out-of-reactor helium circulation system that is being constructed to permit detailed study of the thermomechanical and thermal performance at prototypic steady-state and transient operating conditions of simulated segments of core assemblies for a GCFR Demonstration Plant, as designed by General Atomic Company. It will also permit the expermental verification of predictive analytical models of the GCFR core assemblies needed to reduce operational and safety uncertainties of the GCFR. Full-sized blanket assemblies and segments of fuel rod and control rod fuel assemblies will be simulated with test bundles of electrically powered fuel rod or blanket rod simulators. The loop will provide the steady-state and margin test requirements of bundle power and heat removal, and of helium coolant flow rate, pressure, and temperature for test bundles having up to 91 rods; these requirements set the maximum power, coolant helium flow, and thermal requirements for the loop. However, the size of the test vessel that contains the test bundles will be determined by the bundles that simulate a full-sized GCFR blanket assembly. The loop will also provide for power and coolant transients to simulate transient operation of GCFR core assemblies, including the capability for rapid helium depressurization to simulate the depressurization class of GCFR accidents. In addition, the loop can be used as an out-of-reactor test bed for characterizing in-reactor test bundle configurations.

  17. New approach to the design of core support structures for large LMFBR plants

    SciTech Connect

    Burelbach, J.P.; Kann, W.J.; Pan, Y.C.; Saiveau, J.G.; Seidensticker, R.W.

    1984-01-01

    The paper describes an innovative design concept for a LMFBR Core Support Structure. A hanging Core Support Structure is described and analyzed. The design offers inherent safety features, constructibility advantages, and potential cost reductions.

  18. Seismic responses of a pool-type fast reactor with different core support designs

    SciTech Connect

    Wu, Ting-shu; Seidensticker, R.W. (Argonne National Lab., IL (USA))

    1989-01-01

    In designing the core support system for a pool-type fast reactor, there are many issues which must be considered in order to achieve an optimum and balanced design. These issues include safety, reliability, as well as costs. Several design options are possible to support the reactor core. Different core support options yield different frequency ranges and responses. Seismic responses of a large pool-type fast reactor incorporated with different core support designs have been investigated. 4 refs., 3 figs.

  19. Application of core structural design guidelines in conceptual fuel pin design. [LMFBR

    Microsoft Academic Search

    M. R. Patel; J. D. Stephen

    1979-01-01

    The paper describes an application of the Draft RDT Standards F9-7, -8, and -9 to conceptual design of Fast Breeder Reactor (FBR) fuel pins. The Standards are being developed to provide guidelines for structural analysis and design of the FBR core components which have limited ductility at high fluences and are not addressed by the prevalent codes. The development is

  20. Effects of lumbar artificial disc design on intervertebral mobility: in vivo comparison between mobile-core and fixed-core.

    PubMed

    Delécrin, Joël; Allain, Jérôme; Beaurain, Jacques; Steib, Jean-Paul; Huppert, Jean; Chataigner, Hervé; Ameil, Marc; Aubourg, Lucie; Nguyen, Jean-Michel

    2012-06-01

    Although in theory, the differences in design between fixed-core and mobile-core prostheses should influence motion restoration, in vivo kinematic differences linked with prosthesis design remained unclear. The aim of this study was to investigate the rationale that the mobile-core design seems more likely to restore physiological motion since the translation of the core could help to mimic the kinematic effects of the natural nucleus. In vivo intervertebral motion characteristics of levels implanted with the mobile-core prosthesis were compared with untreated levels of the same population, levels treated by a fixed-core prosthesis, and normal levels (data from literature). Patients had a single-level implantation at L4L5 or L5S1 including 72 levels with a mobile-core prosthesis and 33 levels with a fixed-core prosthesis. Intervertebral mobility characteristics included the range of motion (ROM), the motion distribution between flexion and extension, the prosthesis core translation (CT), and the intervertebral translation (VT). A method adapted to the implanted segments was developed to measure the VT: metal landmarks were used instead of the bony landmarks. The reliability assessment of the VT measurement method showed no difference between three observers (p < 0.001), a high level of agreement (ICC = 0.908) and an interobserver precision of 0.2 mm. Based on this accurate method, this in vivo study demonstrated that the mobile-core prosthesis replicated physiological VT at L4L5 levels but not at L5S1 levels, and that the fixed-core prosthesis did not replicate physiological VT at any level by increasing VT. As the VT decreased when the CT increased (p < 0.001) it was proven that the core mobility minimized the VT. Furthermore, some physiologic mechanical behaviors seemed to be maintained: the VT was higher at implanted the L4L5 level than at the implanted L5S1 level, and the CT appeared lower at the L4L5 level than at the L5S1 level. ROM and motion distribution were not different between the mobile-core prosthesis and the fixed-core prosthesis implanted levels. This study validated in vivo the concept that a mobile-core helps to restore some physiological mechanical characteristics of the VT at the implanted L4L5 level, but also showed that the minimizing effect of core mobility on the VT was not sufficient at the L5S1 level. PMID:21153595

  1. Chapter 5 Embedded Core Test Fundamentals 1 Design-for-Test for Digital IC's and Embedded Core Systems Alfred L. Crouch

    E-print Network

    Greenwood, Garrison W.

    Chapter 5 Embedded Core Test Fundamentals 1 Design-for-Test for Digital IC's and Embedded Core Access #12;Chapter 5 Embedded Core Test Fundamentals 2 Design-for-Test for Digital IC's and Embedded Core with Inserted Test Gate-Level Netlist with Mixed Test FIRM Layout GDSII with No Test Layout with Test from

  2. Design study for an advanced liquid-metal fast breeder reactor core with a high burnup

    Microsoft Academic Search

    T. Inagaki; H. Kuga; M. Suzuki; T. Yokoyama; M. Yamaoka; K. Kaneto; M. Ohashi; K. Kurihara

    1989-01-01

    Design studies are performed for a commercial liquid-metal fast breeder reactor core that can achieve a burnup of 200 GWd\\/t. A plutonium-type asymmetric parfait core with two different plutonium-enriched zones in the axial direction as well as in the radial direction is studied. This core concept solves core design problems related to high burnup, and it is possible to achieve

  3. Placement and Routing for Non-Rectangular Embedded Programmable Logic Cores in SoC Design

    E-print Network

    Wilton, Steve

    Placement and Routing for Non-Rectangular Embedded Programmable Logic Cores in SoC Design Tony Wong Vancouver, B.C., Canada Abstract As SoC design enters into mainstream usage, the ability to make post. These cores are like any other IP in the SoC design methodology, except that their function can be changed

  4. Media digital signal processor core design for multimedia application

    NASA Astrophysics Data System (ADS)

    Liu, Peng; Yu, Guo-jun; Cai, Wei-guang; Yao, Qing-dong

    2006-02-01

    An embedded single media processor named MediaDSP3200 core fabricated in a six-layer metal 0.18um CMOS process which implemented the RISC instruction set, DSP data processing instruction set and single-instruction-multiple-data (SIMD) multimedia-enhanced instruction set is described. MediaDSP3200 fuses RISC architecture and DSP computation capability thoroughly, which achieves RISC fundamental, DSP extended and single instruction multiple data (SIMD) instruction set with various addressing modes in a unified pipeline stage architecture. These characteristics enhance system digital signal processing performance greatly. The test processor can achieve 32x32-bit multiply-accumulate (MAC) of 320 MOPS, with 16x16-bit MAC of 1280MOPS. The test processor dissipates 600mW at 1.8v, 320MHz. Also, the implementation was primarily standard cell logic design style. MediaDSP3200 targets diverse embedded application systems, which need both powerful processing/control capability and low-cost budget, e.g. set-top-boxes, video conferencing, DTV, etc. MediaDSP3200 instruction set architecture, addressing mode, pipeline design, SIMD feature, split-ALU and MAC are described in this paper. Finally, the performance benchmark based on H.264 and MPEG decoder algorithm are given in this paper.

  5. Feasibility study on nuclear core design for soluble boron free small modular reactor

    NASA Astrophysics Data System (ADS)

    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.

  6. Design and implementation of a high performance matrix multiplier core for Xilinx Virtex FPGAs

    Microsoft Academic Search

    S. Belkacemi; K. Benkrid; D. Crookes; A. Benkrid

    2003-01-01

    Matrix multiplication is a core operation in digital signal processing operations with a variety of applications such as image processing, computer graphics, sonar processing and robotics. This paper presents the design and implementation of a high performance, fully parallel matrix multiplication core. The core is parameterised and scalable in terms of the matrices' dimensions (row and column number) and the

  7. Using Electronic Meeting System Support in the Design of the Graduate Core Curriculum.

    ERIC Educational Resources Information Center

    Spuck, Dennis W.; And Others

    1995-01-01

    Discusses uses of an electronic meeting system (EMS) to aid in designing graduate core curricula. Presents results from a study of a seven-member task force that used EMS for seven months to facilitate selection of core courses for master's degree programs. A diagram illustrates the task force's graduate core review process and an appendix…

  8. Design of low-loss and highly birefringent hollow-core photonic crystal fiber

    Microsoft Academic Search

    P. J. Roberts; D. P. Williams; H. Sabert; B. J. Mangan; D. M. Bird; T. A. Birks; J. C. Knight; P. St. J. Russell

    2006-01-01

    A practical hollow-core photonic crystal fiber design suitable for attaining low-loss propagation is analyzed. The geometry involves a number of localized elliptical features positioned on the glass ring that surrounds the air core and separates the core and cladding regions. The size of each feature is tuned so that the composite core-surround geometry is antiresonant within the cladding band gap,

  9. A Low-Overhead Design for Testability and Test Generation Technique for Core-Based Systems

    Microsoft Academic Search

    Indradeep Ghoshf; Niraj K. Jhat; Sujit Dey

    1997-01-01

    In a fundamental paradigm shift in system design, entire systems are being built on a single chip, using multiple embedded cores. Though the newest system design methodology has several advantages in terms of time-to-market and system cost, testing such core-based systems is difficult due to the problem of justifying test sequences at the inputs of a core embedded deep in

  10. Programmable logic IP cores in SoC design: opportunities and challenges

    Microsoft Academic Search

    Steven J. E. Wilton; Resve Saleh

    2001-01-01

    As SoC design enters into mainstream usage, the ability to make post-fabrication changes will become more and more attractive. This ability can be realized using programmable logic cores. These cores are like any other IP in the SoC design methodology, except that their function can be changed after fabrication. This paper outlines ways in which programmable logic cores can simplify

  11. HW\\/SW co-design for multi-core system on ESL virtual platform

    Microsoft Academic Search

    I-Yao Chuang; Tso-Yi Fan; Chi-Hung Lin; Chun-Nan Liu; Jen-Chieh Yeh

    2011-01-01

    Multi-core system and the associated software parallelization techniques have become one of the major trends of SoC design. A multi-core system with high hardware efficiency and software parallelism has the potential of achieving higher system performance and lower power consumption. This paper reveals how system performance prediction and analysis for multi-core system can be done at early design stage before

  12. Direct access test scheme-design of block and core cells for embedded ASICs

    Microsoft Academic Search

    V. Immaneni; S. Raman

    1990-01-01

    Intel requires the use of a direct-access test scheme in embedded-core or block-based ASIC (application-specific integrated-circuit) designs. This scheme provides for separate testing of individual block or core cells using proven test vectors. The authors discuss the design modifications for block cells with low pin counts, user application blocks, and large cores with high pin counts. The implementation and verification

  13. Conceptual Design of a Modular Island Core Fast Breeder Reactor \\

    Microsoft Academic Search

    Mitsuru KAMBE

    2002-01-01

    A metal fueled modular island core sodium cooled fast breeder reactor concept RAPID-M to improve reactor per- formance and proliferation resistance and to accommodate various power requirements has been demonstrated. The essential feature of the RAPID-M concept is that the reactor core consists of integrated fuel assemblies (IFAs) instead of conventional fuel subassemblies. The RAPID concept enables quick and simplified

  14. Core design investigation for a SUPERSTAR small modular lead-cooled fast reactor demonstrator

    Microsoft Academic Search

    S. Bortot; A. Moisseytsev; J. J. Sienicki; Carlo Artioli

    In this paper a preconceptual neutronics design study for a SUstainable Proliferation-resistance Enhanced Refined Secure Transportable Autonomous Reactor (SUPERSTAR) demonstrator is presented. The main goal of achieving the highest realistic power level limited by natural circulation and transportability, while providing energy security and proliferation resistance thanks to a long core lifetime design has been satisfactorily attained. A preliminary core configuration

  15. DESIGN AND OPERATION OF A WIRELINE RETRIEVABLE MOTOR DRIVEN CORE BARREL

    E-print Network

    DESIGN AND OPERATION OF A WIRELINE RETRIEVABLE MOTOR DRIVEN CORE BARREL OCEAN DRILLING PROGRAM) Ocean Research Institute of the University of Tokyo (Japan) National Science Foundation (United States of a Motor-Driven Core Barrel 9 1.0 Introduction 9 1.1 Conceptual Design 9 Chapter 2: NCB1: Development, Land

  16. Thermal Design of an Ultrahigh Temperature Vapor Core Reactor Combined Cycle Nuclear Power Plant

    Microsoft Academic Search

    Samuel E. Bays; Samim Anghaie; Blair Smith; Travis Knight

    2004-01-01

    Current work modeling high temperature compact heat exchangers may demonstrate the design feasibility of a Vapor Core Reactor (VCR) driven combined cycle power plant. For solid nuclear fuel designs, the cycle efficiency is typically limited by a metallurgical temperature limit which is dictated by fuel and structural melting points. In a vapor core, the gas\\/vapor phase nuclear fuel is uniformly

  17. Performance of truss panels with kagome cores and design of a high authority shape morphing structure

    Microsoft Academic Search

    Ju Wang

    2005-01-01

    This dissertation includes two parts: First, the performance of a light weight truss panels with Kagome cores; Second, design of a high authority morphing structure for hinging and twisting. The performance characteristics of a truss core sandwich panel design based on the 3D Kagome are measured and compared with earlier numerical simulations and the consistency is demonstrated. Panels are fabricated

  18. Current directions in core-shell nanoparticle design

    Microsoft Academic Search

    Wolfgang Schärtl

    2010-01-01

    Ten years ago I wrote a review about the important field of core-shell nanoparticles, focussing mainly on our own work about tracer systems, and briefly addressing polymer-coated nanoparticles as fillers for homogeneous polymer-colloid composites. Since then, the potential use of core-shell nanoparticles as multifunctional sensors or potential smart drug-delivery vehicles in biology and medicine has gained more and more importance,

  19. Identifying and Using ‘Core Competencies’ to Help Design and Assess Undergraduate Neuroscience Curricula

    PubMed Central

    Kerchner, Michael; Hardwick, Jean C.; Thornton, Janice E.

    2012-01-01

    There has been a growing emphasis on the use of core competencies to design and inform curricula. Based on our Faculty for Undergraduate Neuroscience workshop at Pomona we developed a set of neuroscience core competencies. Following the workshop, faculty members were asked to complete an online survey to determine which core competencies are considered most essential and the results are presented. Backward Design principles are then described and we discuss how core competencies, through a backward design process, can be used to design and assess an undergraduate neuroscience curriculum. Oberlin College is used as a case study to describe the use of core competencies to help develop learning objectives, activities, and assessment measures for an undergraduate neuroscience major. PMID:23494749

  20. Design and Implementation of a Videotext Extractor on Dual-Core Platform

    Microsoft Academic Search

    Chih-Lun Fang; Tsung-Han Tsai; Ren-Chih Kuo

    2008-01-01

    Many videotexts exist in TV programs. Some videotexts provide valuable information. Thus, an efficient design to extract these videotexts is requested. Existing videotext extractors work on the PC platform and they are difficult to achieve real-time extraction and integration. Therefore, this work designs a videotext extractor on a dual-core platform. A distributed design framework for a dual-core platform is proposed.

  1. Optimization of burnable poison design for Pu incineration in fully fertile free PWR core

    SciTech Connect

    Fridman, E.; Shwageraus, E.; Galperin, A. [Dept. of Nuclear Engineering, Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel)

    2006-07-01

    The design challenges of the fertile-free based fuel (FFF) can be addressed by careful and elaborate use of burnable poisons (BP). Practical fully FFF core design for PWR reactor has been reported in the past [1]. However, the burnable poison option used in the design resulted in significant end of cycle reactivity penalty due to incomplete BP depletion. Consequently, excessive Pu loading were required to maintain the target fuel cycle length, which in turn decreased the Pu burning efficiency. A systematic evaluation of commercially available BP materials in all configurations currently used in PWRs is the main objective of this work. The BP materials considered are Boron, Gd, Er, and Hf. The BP geometries were based on Wet Annular Burnable Absorber (WABA), Integral Fuel Burnable Absorber (IFBA), and Homogeneous poison/fuel mixtures. Several most promising combinations of BP designs were selected for the full core 3D simulation. All major core performance parameters for the analyzed cases are very close to those of a standard PWR with conventional UO{sub 2} fuel including possibility of reactivity control, power peaking factors, and cycle length. The MTC of all FFF cores was found at the full power conditions at all times and very close to that of the UO{sub 2} core. The Doppler coefficient of the FFF cores is also negative but somewhat lower in magnitude compared to UO{sub 2} core. The soluble boron worth of the FFF cores was calculated to be lower than that of the UO{sub 2} core by about a factor of two, which still allows the core reactivity control with acceptable soluble boron concentrations. The main conclusion of this work is that judicial application of burnable poisons for fertile free fuel has a potential to produce a core design with performance characteristics close to those of the reference PWR core with conventional UO{sub 2} fuel. (authors)

  2. Current directions in core-shell nanoparticle design

    NASA Astrophysics Data System (ADS)

    Schärtl, Wolfgang

    2010-06-01

    Ten years ago I wrote a review about the important field of core-shell nanoparticles, focussing mainly on our own work about tracer systems, and briefly addressing polymer-coated nanoparticles as fillers for homogeneous polymer-colloid composites. Since then, the potential use of core-shell nanoparticles as multifunctional sensors or potential smart drug-delivery vehicles in biology and medicine has gained more and more importance, affording special types of multi-functionalized and bio-compatible nanoparticles. In this new review article, I try to address the most important developments during the last ten years. This overview is mainly based on frequently cited and more specialized recent review articles from leaders in their respective field. We will consider a variety of nanoscopic core-shell architectures from highly fluorescent nanoparticles (NPs), protected magnetic NPs, multifunctional NPs, thermoresponsive NPs and biocompatible systems to, finally, smart drug-delivery systems.Ten years ago I wrote a review about the important field of core-shell nanoparticles, focussing mainly on our own work about tracer systems, and briefly addressing polymer-coated nanoparticles as fillers for homogeneous polymer-colloid composites. Since then, the potential use of core-shell nanoparticles as multifunctional sensors or potential smart drug-delivery vehicles in biology and medicine has gained more and more importance, affording special types of multi-functionalized and bio-compatible nanoparticles. In this new review article, I try to address the most important developments during the last ten years. This overview is mainly based on frequently cited and more specialized recent review articles from leaders in their respective field. We will consider a variety of nanoscopic core-shell architectures from highly fluorescent nanoparticles (NPs), protected magnetic NPs, multifunctional NPs, thermoresponsive NPs and biocompatible systems to, finally, smart drug-delivery systems. Dedicated to Professor Manfred Schmidt on the occasion of his 60th birthday

  3. Ferrite core loss for power magnetic components design

    Microsoft Academic Search

    Waseem Roshen

    1991-01-01

    A practical method is presented for computing high-frequency ferrite core losses in the magnetic component for arbitrary voltage waveforms. The model presented requires only a few material parameters as input. To calculate ferrite hysteresis losses, a model based on empirical rules is employed. For high-frequency eddy current losses, a built phenomenon is assumed. It is demonstrated that the hysteresis model

  4. An Effective Instructional Design at Iowa Lakes Community College to Make Hard Core Unemployed People Employable.

    ERIC Educational Resources Information Center

    Schorzmann, Eugene F.

    In order to meet the educational needs of the hard-core unemployed, an instructional program known as the "Alternative Career Center" was designed at Iowa Lakes Community College to prepare those identified by the Comprehensive Employment and Training Act for employment. After reviewing the literature on educational programs for the hard-core

  5. Design and Analysis of a High-Speed Claw Pole Motor With Soft Magnetic Composite Core

    Microsoft Academic Search

    Yunkai Huang; Jianguo Zhu; Youguang Guo; Zhiwei Lin; Qiansheng Hu

    2007-01-01

    Soft magnetic composite (SMC) material is formed by surface-insulated iron powder particles, generating unique properties like magnetic and thermal isotropy, and very low eddy currents. This paper presents the design and analysis of a high-speed claw pole motor with an SMC stator core for reducing core losses and cost. The analyses of magnetic and thermal fields are conducted based on

  6. Programmable Logic IP Cores in SoC Design: Opportunities and Challenges Steven J.E. Wilton and Resve Saleh

    E-print Network

    Wilton, Steve

    Programmable Logic IP Cores in SoC Design: Opportunities and Challenges Steven J.E. Wilton, B.C., Canada {stevew, res} @ece.ubc.ca Abstract As SoC design enters into mainstream usage be realized using programmable logic cores. These cores are like any other IP in the SoC design methodology

  7. Modeling Core Failure by the Tsai-Wu Criterion in the Design of Foam-Core Sandwich Beams

    Microsoft Academic Search

    E. E. Gdoutos; V. D. Balopoulos; P. A. Kalaitzidis; M. Konsta

    This work is part of an extensive program at the Laboratory of Applied Mechanics of D.U.Th. involving experimental and numerical\\u000a research, to expand our knowledge of composite materials and propose enhanced techniques for rational design of sandwich beams\\u000a and shells. In particular, it is a study of the importance of describing core failure in elastic sandwich beams by the Tsai–Wu

  8. 76 FR 14825 - Core Principles and Other Requirements for Designated Contact Markets

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ...3038-AD09 Core Principles and Other Requirements for Designated Contact Markets AGENCY: Commodity Futures Trading Commission. ACTION...site at http://www.cftc.gov. FOR FURTHER INFORMATION CONTACT: Nancy Markowitz, Assistant Deputy Director,...

  9. Development of optimized core design and analysis methods for high power density BWRs

    E-print Network

    Shirvan, Koroush

    2013-01-01

    Increasing the economic competitiveness of nuclear energy is vital to its future. Improving the economics of BWRs is the main goal of this work, focusing on designing cores with higher power density, to reduce the BWR ...

  10. DESIGN AND CORE COMPETENCY, THE MISSING LINKS Eric Bonjour1

    E-print Network

    Paris-Sud XI, Université de

    competency building are key issues for managers of product development process, design skills networks Designers have to develop products with drastic performances related to cost, delay, quality, environmental competency. This framework is a first step beyond an efficient competency based management of design

  11. Design aspects of medium power double rotor radial flux air-cored PM wind generators

    Microsoft Academic Search

    J. A. Stegmann; M. J. Kamper

    2009-01-01

    The electromagnetic and mechanical design aspects of optimally designed double rotor radial flux permanent magnet wind generators with non-overlap air-cored (iron-less) stator windings are analyzed in this paper. The optimal design is based on an accurate analytical model and is confirmed with finite element analysis. It is shown, amongst other things, that the electromagnetic design and not the mechanical design

  12. Architecting voltage islands in core-based system-on-a-chip designs

    Microsoft Academic Search

    Jingcao Hu; Youngsoo Shin; Nagu R. Dhanwada; Radu Marculescu

    2004-01-01

    Voltage islands enable core-level power optimization for System-on-Chip (SoC) designs by utilizing a unique supply voltage for each core. Architecting voltage islands involves island partition creation, voltage level assignment and floorplanning. The task of island partition creation and level assignment have to be done simultaneously in a floorplanning context due to the physical constraints involved in the design process. This

  13. LMR design concepts for transuranic management in low sodium void worth cores

    SciTech Connect

    Hill, R.N.

    1991-01-01

    The fuel cycle processing techniques and hard neuron spectrum of the Integral Fast Reactor (IFR) metal fuel cycle have favorable characteristics for the management of transuranics; and the wide range of breeding characteristics available in metal fuelled cores provides for flexibility in transuranic management strategy. Previous studies indicate that most design options which decrease the breeding ratio also show a decrease in sodium void worth; therefore, low void worths are achievable in transuranic burning (low breeding ratio) core designs. This paper describes numerous trade studies assessing various design options for a low void worth transuranic burner core. A flat annular core design appears to be a promising concept; the high leakage geometry yields a low breeding ratio and small sodium void worth. To allow flexibility in breeding characteristics, alternate design options which achieve fissile self-sufficiency are also evaluated. A self-sufficient core design which is interchangeable with the burner core and maintains a low sodium void worth is developed. 13 refs., 1 fig., 4 tabs.

  14. Design of low-loss and highly birefringent hollow-core photonic crystal fiber.

    PubMed

    Roberts, P J; Williams, D P; Sabert, H; Mangan, B J; Bird, D M; Birks, T A; Knight, J C; Russell, P St J

    2006-08-01

    A practical hollow-core photonic crystal fiber design suitable for attaining low-loss propagation is analyzed. The geometry involves a number of localized elliptical features positioned on the glass ring that surrounds the air core and separates the core and cladding regions. The size of each feature is tuned so that the composite core-surround geometry is antiresonant within the cladding band gap, thus minimizing the guided mode field intensity both within the fiber material and at material/air interfaces. A birefringent design, which involves a 2-fold symmetric arrangement of the features on the core-surround ring, gives rise to wavelength ranges where the effective index difference between the polarization modes is larger than 10(-4). At such high birefringence levels, one of the polarization modes retains favorable field exclusion characteristics, thus enabling low-loss propagation of this polarization channel. PMID:19529102

  15. McCARD for Neutronics Design and Analysis of Research Reactor Cores

    NASA Astrophysics Data System (ADS)

    Shim, Hyung Jin; Park, Ho Jin; Kwon, Soonwoo; Seo, Geon Ho; Hyo Kim, Chang

    2014-06-01

    McCARD is a Monte Carlo (MC) neutron-photon transport simulation code developed exclusively for the neutronics design and analysis of nuclear reactor cores. McCARD is equipped with the hierarchical modeling and scripting functions, the CAD-based geometry processing module, the adjoint-weighted kinetics parameter and source multiplication factor estimation modules as well as the burnup analysis capability for the neutronics design and analysis of both research and power reactor cores. This paper highlights applicability of McCARD for the research reactor core neutronics analysis, as demonstrated for Kyoto University Critical Assembly, HANARO, and YALINA.

  16. Modified Y-TZP core design improves all-ceramic crown reliability.

    PubMed

    Silva, N R F A; Bonfante, E A; Rafferty, B T; Zavanelli, R A; Rekow, E D; Thompson, V P; Coelho, P G

    2011-01-01

    This study tested the hypothesis that all-ceramic core-veneer system crown reliability is improved by modification of the core design. We modeled a tooth preparation by reducing the height of proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. The CAD-based tooth preparation was replicated and positioned in a dental articulator for core and veneer fabrication. Standard (0.5 mm uniform thickness) and modified (2.5 mm height lingual and proximal cervical areas) core designs were produced, followed by the application of veneer porcelain for a total thickness of 1.5 mm. The crowns were cemented to 30-day-aged composite dies and were either single-load-to-failure or step-stress-accelerated fatigue-tested. Use of level probability plots showed significantly higher reliability for the modified core design group. The fatigue fracture modes were veneer chipping not exposing the core for the standard group, and exposing the veneer core interface for the modified group. PMID:21057036

  17. Explosively driven 1 MV output air-core pulse transformer design: Final report

    Microsoft Academic Search

    P. D. A. Champney; C. Eichenberger

    1988-01-01

    This report presents the results of a pulse transformer design program conducted by Pulse Sciences Inc., (PSI) for the Lawrence Livermore National Laboratory (LLNL). The principle program objective was the development of a 1 MV output air-core pulse transformer design compatible with an LLNL explosive driver concept. 34 figs.

  18. Explosively driven 1 MV output air-core pulse transformer design: Final report

    SciTech Connect

    Champney, P.D'A.; Eichenberger, C.

    1988-09-01

    This report presents the results of a pulse transformer design program conducted by Pulse Sciences Inc., (PSI) for the Lawrence Livermore National Laboratory (LLNL). The principle program objective was the development of a 1 MV output air-core pulse transformer design compatible with an LLNL explosive driver concept. 34 figs.

  19. Fusion Engineering and Design 82 (2007) 217236 Advanced power core system for the

    E-print Network

    California at San Diego, University of

    2007-01-01

    Fusion Engineering and Design 82 (2007) 217­236 Advanced power core system for the ARIES-AT power of Wisconsin, Fusion Technology Institute, 1500 Engineering Drive, Madison, WI 53706-1687, USA c Engineering and Design 82 (2007) 217­236 ties on the performance of advanced tokamak power plants [1

  20. Fusion Engineering and Design 80 (2006) 7998 Advanced power core system for the

    E-print Network

    California at San Diego, University of

    2006-01-01

    Fusion Engineering and Design 80 (2006) 79­98 Advanced power core system for the ARIES-AT power of Wisconsin, Fusion Technology Institute, 1500 Engineering Drive, Madison, WI 53706-1687, USA c.06.356 #12;80 A.R. Raffray et al. / Fusion Engineering and Design 80 (2006) 79­98 of new physics

  1. Dynamical analysis of innovative core designs facing unprotected transients with the MAT5 DYN code

    SciTech Connect

    Darmet, G.; Massara, S. [EDF R and D, 1 avenue du general de Gaulle, 92140 Clamart (France)

    2012-07-01

    Since 2007, advanced Sodium-cooled Fast Reactors (SFR) are investigated by CEA, AREVA and EDF in the framework of a joint French collaboration. A prototype called ASTRID, sets out to demonstrate progress made in SFR technology, is due to operate in the years 2020's. The modeling of unprotected transients by computer codes is one of the key safety issues in the design approach to such SFR systems. For that purpose, the activity on CATHARE, which is the reference code for the transient analysis of ASTRID, has been strengthened during last years by CEA. In the meantime, EDF has developed a simplified and multi-channel code, named MAT5 DYN, to analyze and validate innovative core designs facing protected and unprotected transients. First, the paper consists in a description of MAT5 DYN: a code based on the existing code MAT4 DYN including major improvements on geometry description and physical modeling. Second, two core designs based on the CFV core design developed at CEA are presented. Then, the dynamic response of those heterogeneous cores is analyzed during unprotected loss of flow (ULOF) transient and unprotected transient of power (UTOP). The results highlight the importance of the low void core effect specific to the CFV design. Such an effect, when combined with a sufficient primary pump halving time and an optimized cooling group scheme, allows to delay (or, possibly, avoid) the sodium boiling onset during ULOF accidents. (authors)

  2. Design and performance of a pulse transformer based on Fe-based nanocrystalline core

    Microsoft Academic Search

    Liu Yi; Feng Xibo; Fuchang Lin

    2011-01-01

    A dry-type pulse transformer based on Fe-based nanocrystalline core with a load of 0.88 nF, output voltage of more than 65 kV, and winding ratio of 46 is designed and constructed. The dynamic characteristics of Fe-based nanocrystalline core under the impulse with the pulse width of several microseconds were studied. The pulse width and incremental flux density have an important

  3. Design and Analysis of a Permanent Magnet Claw Pole\\/Transverse Flux Motor with SMC Core

    Microsoft Academic Search

    YouGuang Guo; Jian Guo Zhu; Haiwei Lu

    2005-01-01

    This paper presents the design and analysis of a claw pole\\/transverse flux motor (CPTFM) with soft magnetic composite (SMC) core and permanent magnet flux-concentrating rotor. Three-dimensional magnetic field finite element analysis is conducted to accurately calculate key motor parameters such as winding flux, back electromotive force, winding inductance, and core loss. Equivalent electric circuit is derived under optimum brushless DC

  4. Design manufacture and test of a cryo-stable Offner relay using aluminum foam core optics

    Microsoft Academic Search

    Ryan S. McClelland

    2001-01-01

    Aluminum foam core optics have the desirable characteristics of being lightweight, cryo-stable, and low cost. The availability of high quality aluminum foam and a bare aluminum super-polishing process have allowed high performance foam core optics made entirely of aluminum to be produced. Mirrors with integral mounts were designed for minimum surface error induced by self-weight deflection, thermal gradients, and mounting

  5. Development of an advanced core analysis system for boiling water reactor designs

    Microsoft Academic Search

    Hiromi Maruyama; Junichi Koyama; Motoo Aoyama; Kazuya Ishii; Atsushi Zukeran; Takashi Kiguchi; Akira Nishimura

    1997-01-01

    A core analysis system has been developed for the recent advanced designs of boiling water reactors. This system consists of a fuel assembly analysis code VMONT and a three-dimensional core simulator COSNEX. To cope with heterogeneous structures found in the recent high-performance fuel, VMONT employs a Monte Carlo neutron transport calculation method. COSNEX is based on a three-group nodal expansion

  6. Gradient coil design considerations for iron core interventional magnets.

    PubMed

    Ersahin, A; Bronskill, M J; Henkelman, R M; Collick, B; Hinks, R S

    1998-01-01

    The requirements for access and imaging performance compete in the design of open-concept MR magnets and gradient coils. We conducted a theoretical and experimental investigation of gradient coil design using both solid and laminated pole piece construction to determine whether adequate eddy current control can be obtained without shielded gradient coils while maintaining good patient access and high gradient performance. Eddy currents, gradient characteristics, gradient efficiency, and magnet openness are compared and contrasted for various construction options based on a compact, .27 T iron yoke magnet. The resulting pole pieces and gradient coils have high efficiency for an interventional open-configuration magnet while taking up minimal space between the poles for improved patient access. PMID:9786154

  7. Preliminary core design studies for the advanced burner reactor over a wide range of conversion ratios

    Microsoft Academic Search

    E. A. Hoffman; W. S. Yang; R. N. Hill

    2008-01-01

    A consistent set of designs for 1000 MWt commercial-scale sodium-cooled Advance Burner Reactors (ABR) have been developed for both metal and oxide-fueled cores with conversion ratios from breakeven (CR=1.0) to fertile-free (CR=0.0). These designs are expected to satisfy thermal and irradiation damage limits based on the currently available data. The very low conversion ratio designs require fuel that is beyond

  8. Analysis of Stainless Steel Sandwich Panels with a Metal Foam Core for Lightweight Fan Blade Design

    NASA Technical Reports Server (NTRS)

    Min, James B.; Ghosn, Louis J.; Lerch, Bradley A.; Raj, Sai V.; Holland, Frederic A., Jr.; Hebsur, Mohan G.

    2004-01-01

    The quest for cheap, low density and high performance materials in the design of aircraft and rotorcraft engine fan and propeller blades poses immense challenges to the materials and structural design engineers. The present study investigates the use of a sandwich foam fan blade mae up of solid face sheets and a metal foam core. The face sheets and the metal foam core material were an aerospace grade precipitation hardened 17-4 PH stainless steel with high strength and high toughness. The resulting structures possesses a high stiffness while being lighter than a similar solid construction. The material properties of 17-4 PH metal foam are reviewed briefly to describe the characteristics of sandwich structure for a fan blade application. A vibration analysis for natural frequencies and a detailed stress analysis on the 17-4 PH sandwich foam blade design for different combinations of kin thickness and core volume are presented with a comparison to a solid titanium blade.

  9. Core Noise: Implications of Emerging N+3 Designs and Acoustic Technology Needs

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a summary of the core-noise implications of NASA's primary N+3 aircraft concepts. These concepts are the MIT/P&W D8.5 Double Bubble design, the Boeing/GE SUGAR Volt hybrid gas-turbine/electric engine concept, the NASA N3-X Turboelectric Distributed Propulsion aircraft, and the NASA TBW-XN Truss-Braced Wing concept. The first two are future concepts for the Boeing 737/Airbus A320 US transcontinental mission of 180 passengers and a maximum range of 3000 nm. The last two are future concepts for the Boeing 777 transpacific mission of 350 passengers and a 7500 nm range. Sections of the presentation cover: turbofan design trends on the N+1.5 time frame and the already emerging importance of core noise; the NASA N+3 concepts and associated core-noise challenges; the historical trends for the engine bypass ratio (BPR), overall pressure ratio (OPR), and combustor exit temperature; and brief discussion of a noise research roadmap being developed to address the core-noise challenges identified for the N+3 concepts. The N+3 conceptual aircraft have (i) ultra-high bypass ratios, in the rage of 18 - 30, accomplished by either having a small-size, high-power-density core, an hybrid design which allows for an increased fan size, or by utilizing a turboelectric distributed propulsion design; and (ii) very high OPR in the 50 - 70 range. These trends will elevate the overall importance of turbomachinery core noise. The N+3 conceptual designs specify the need for the development and application of advanced liners and passive and active control strategies to reduce the core noise. Current engineering prediction of core noise uses semi-empirical methods based on older turbofan engines, with (at best) updates for more recent designs. The models have not seen the same level of development and maturity as those for fan and jet noise and are grossly inadequate for the designs considered for the N+3 time frame. An aggressive program for the development of updated noise prediction tools for integrated core assemblies as well as and strategies for noise reduction and control is needed in order to meet the NASA N+3 noise goals. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic.

  10. Baseline Design Compliance Matrix for the Rotary Mode Core Sampling System

    SciTech Connect

    LECHELT, J.A.

    2000-10-17

    The purpose of the design compliance matrix (DCM) is to provide a single-source document of all design requirements associated with the fifteen subsystems that make up the rotary mode core sampling (RMCS) system. It is intended to be the baseline requirement document for the RMCS system and to be used in governing all future design and design verification activities associated with it. This document is the DCM for the RMCS system used on Hanford single-shell radioactive waste storage tanks. This includes the Exhauster System, Rotary Mode Core Sample Trucks, Universal Sampling System, Diesel Generator System, Distribution Trailer, X-Ray Cart System, Breathing Air Compressor, Nitrogen Supply Trailer, Casks and Cask Truck, Service Trailer, Core Sampling Riser Equipment, Core Sampling Support Trucks, Foot Clamp, Ramps and Platforms and Purged Camera System. Excluded items are tools such as light plants and light stands. Other items such as the breather inlet filter are covered by a different design baseline. In this case, the inlet breather filter is covered by the Tank Farms Design Compliance Matrix.

  11. PWR core design, neutronics evaluation and fuel cycle analysis for thorium-uranium breeding recycle

    SciTech Connect

    Bi, G.; Liu, C.; Si, S. [Shanghai Nuclear Engineering Research and Design Inst., No. 29, Hongcao Road, Shanghai, 200233 (China)

    2012-07-01

    This paper was focused on core design, neutronics evaluation and fuel cycle analysis for Thorium-Uranium Breeding Recycle in current PWRs, without any major change to the fuel lattice and the core internals, but substituting the UOX pellet with Thorium-based pellet. The fuel cycle analysis indicates that Thorium-Uranium Breeding Recycle is technically feasible in current PWRs. A 4-loop, 193-assembly PWR core utilizing 17 x 17 fuel assemblies (FAs) was taken as the model core. Two mixed cores were investigated respectively loaded with mixed reactor grade Plutonium-Thorium (PuThOX) FAs and mixed reactor grade {sup 233}U-Thorium (U{sub 3}ThOX) FAs on the basis of reference full Uranium oxide (UOX) equilibrium-cycle core. The UOX/PuThOX mixed core consists of 121 UOX FAs and 72 PuThOX FAs. The reactor grade {sup 233}U extracted from burnt PuThOX fuel was used to fabrication of U{sub 3}ThOX for starting Thorium-. Uranium breeding recycle. In UOX/U{sub 3}ThOX mixed core, the well designed U{sub 3}ThOX FAs with 1.94 w/o fissile uranium (mainly {sup 233}U) were located on the periphery of core as a blanket region. U{sub 3}ThOX FAs remained in-core for 6 cycles with the discharged burnup achieving 28 GWD/tHM. Compared with initially loading, the fissile material inventory in U{sub 3}ThOX fuel has increased by 7% via 1-year cooling after discharge. 157 UOX fuel assemblies were located in the inner of UOX/U{sub 3}ThOX mixed core refueling with 64 FAs at each cycle. The designed UOX/PuThOX and UOX/U{sub 3}ThOX mixed core satisfied related nuclear design criteria. The full core performance analyses have shown that mixed core with PuThOX loading has similar impacts as MOX on several neutronic characteristic parameters, such as reduced differential boron worth, higher critical boron concentration, more negative moderator temperature coefficient, reduced control rod worth, reduced shutdown margin, etc.; while mixed core with U{sub 3}ThOX loading on the periphery of core has no visible impacts on neutronic characteristics compared with reference full UOX core. The fuel cycle analysis has shown that {sup 233}U mono-recycling with U{sub 3}ThOX fuel could save 13% of natural uranium resource compared with UOX once through fuel cycle, slightly more than that of Plutonium single-recycling with MOX fuel. If {sup 233}U multi-recycling with U{sub 3}ThOX fuel is implemented, more natural uranium resource would be saved. (authors)

  12. The design and performance of IceCube DeepCore

    NASA Astrophysics Data System (ADS)

    Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Allen, M. M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brown, A. M.; Buitink, S.; Caballero-Mora, K. S.; Carson, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; Cruz Silva, A. H.; D'Agostino, M. V.; Danninger, M.; Daughhetee, J.; Davis, J. C.; De Clercq, C.; Degner, T.; Demirörs, L.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dierckxsens, M.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, B.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Kroll, G.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lünemann, J.; Madsen, J.; Marotta, A.; Maruyama, R.; Mase, K.; Matis, H. S.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pérez de los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Schmidt, T.; Schönwald, A.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Stüer, M.; Sullivan, G. W.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; van Eijndhoven, N.; Vandenbroucke, J.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Zoll, M.

    2012-05-01

    The IceCube neutrino observatory in operation at the South Pole, Antarctica, comprises three distinct components: a large buried array for ultrahigh energy neutrino detection, a surface air shower array, and a new buried component called DeepCore. DeepCore was designed to lower the IceCube neutrino energy threshold by over an order of magnitude, to energies as low as about 10 GeV. DeepCore is situated primarily 2100 m below the surface of the icecap at the South Pole, at the bottom center of the existing IceCube array, and began taking physics data in May 2010. Its location takes advantage of the exceptionally clear ice at those depths and allows it to use the surrounding IceCube detector as a highly efficient active veto against the principal background of downward-going muons produced in cosmic-ray air showers. DeepCore has a module density roughly five times higher than that of the standard IceCube array, and uses photomultiplier tubes with a new photocathode featuring a quantum efficiency about 35% higher than standard IceCube PMTs. Taken together, these features of DeepCore will increase IceCube's sensitivity to neutrinos from WIMP dark matter annihilations, atmospheric neutrino oscillations, galactic supernova neutrinos, and point sources of neutrinos in the northern and southern skies. In this paper we describe the design and initial performance of DeepCore.

  13. The Design and Performance of IceCube DeepCore

    NASA Technical Reports Server (NTRS)

    Stamatikos, M.

    2012-01-01

    The IceCube neutrino observatory in operation at the South Pole, Antarctica, comprises three distinct components: a large buried array for ultrahigh energy neutrino detection, a surface air shower array, and a new buried component called DeepCore. DeepCore was designed to lower the IceCube neutrino energy threshold by over an order of magnitude, to energies as low as about 10 GeV. DeepCore is situated primarily 2100 m below the surface of the icecap at the South Pole, at the bottom center of the existing IceCube array, and began taking pbysics data in May 2010. Its location takes advantage of the exceptionally clear ice at those depths and allows it to use the surrounding IceCube detector as a highly efficient active veto against the principal background of downward-going muons produced in cosmic-ray air showers. DeepCore has a module density roughly five times higher than that of the standard IceCube array, and uses photomultiplier tubes with a new photocathode featuring a quantum efficiency about 35% higher than standard IceCube PMTs. Taken together, these features of DeepCore will increase IceCube's sensitivity to neutrinos from WIMP dark matter annihilations, atmospheric neutrino oscillations, galactic supernova neutrinos, and point sources of neutrinos in the northern and southern skies. In this paper we describe the design and initial performance of DeepCore.

  14. Verification of JUPITER Standard Analysis Method for Upgrading Joyo MK-III Core Design and Management

    NASA Astrophysics Data System (ADS)

    Maeda, Shigetaka; Ito, Chikara; Sekine, Takashi; Aoyama, Takafumi

    In the experimental fast reactor Joyo, loading of irradiation test rigs causes a decrease in excess reactivity because the rigs contain less fissile materials than the driver fuel. In order to carry out duty operation cycles using as many irradiation rigs as possible, it is necessary to upgrade the core performance to increase its excess reactivity and irradiation capacity. Core modification plans have been considered, such as the installation of advanced radial reflectors and reduction of the number of control rods. To implement such core modifications, it is first necessary to improve the prediction accuracy in core design and to optimize safety margins. In the present study, verification of the JUPITER fast reactor standard analysis method was conducted through a comparison between the calculated and the measured Joyo MK-III core characteristics, and it was concluded that the accuracy for a small sodium-cooled fast reactor with a hard neutron spectrum was within 5 % of unity. It was shown that, the performance of the irradiation bed core could be upgraded by the improvement of the prediction accuracy of the core characteristics and optimization of safety margins.

  15. Rational design of a super core promoter that enhances gene expression.

    PubMed

    Juven-Gershon, Tamar; Cheng, Susan; Kadonaga, James T

    2006-11-01

    Transcription is a critical component in the expression of genes. Here we describe the design and analysis of a potent core promoter, termed super core promoter 1 (SCP1), which directs high amounts of transcription by RNA polymerase II in metazoans. SCP1 contains four core promoter motifs-the TATA box, initiator (Inr), motif ten element (MTE) and downstream promoter element (DPE)-in a single promoter, and is distinctly stronger than the cytomegalovirus (CMV) IE1 and adenovirus major late (AdML) core promoters both in vitro and in vivo. Each of the four core promoter motifs is needed for full SCP1 activity. SCP1 is bound efficiently by TFIID and exhibits a high propensity to form productive transcription complexes. SCP1 and related super core promoters (SCPs) with multiple core promoter motifs will be useful for the biophysical analysis of TFIID binding to DNA, the biochemical investigation of the transcription process and the enhancement of gene expression in cells. PMID:17124735

  16. Modeling and design of a reload PWR core for a 48-month fuel cycle

    SciTech Connect

    McMahon, M.V.; Driscoll, M.J.; Todreas, N.E. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1997-05-01

    The objective of this research was to use state-of-the-art nuclear and fuel performance packages to evaluate the feasibility and costs of a 48 calendar month core in existing pressurized water reactor (PWR) designs, considering the full range of practical design and economic considerations. The driving force behind this research is the desire to make nuclear power more economically competitive with fossil fuel options by expanding the scope for achievement of higher capacity factors. Using CASMO/SIMULATE, a core design with fuel enriched to 7{sup w}/{sub o} U{sup 235} for a single batch loaded, 48-month fuel cycle has been developed. This core achieves an ultra-long cycle length without exceeding current fuel burnup limits. The design uses two different types of burnable poisons. Gadolinium in the form of gadolinium oxide (Gd{sub 2}O{sub 3}) mixed with the UO{sub 2} of selected pins is sued to hold down initial reactivity and to control flux peaking throughout the life of the core. A zirconium di-boride (ZrB{sub 2}) integral fuel burnable absorber (IFBA) coating on the Gd{sub 2}O{sub 3}-UO{sub 2} fuel pellets is added to reduce the critical soluble boron concentration in the reactor coolant to within acceptable limits. Fuel performance issues of concern to this design are also outlined and areas which will require further research are highlighted.

  17. Core design and safety studies for a small modular fast reactor

    SciTech Connect

    Yang, W. S.; Cahalan, J. E.; Dunn, F. E. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2006-07-01

    The paper describes the core design and performance characteristics and the safety analysis results for a 50 MWe small modular fast reactor design that was developed jointly by ANL, CEA, and JNC as an international collaborative effort. The main goal in the core design was to achieve a 30-year lifetime with no refueling. In order to minimize the burnup reactivity swing, metal fuel with a high heavy metal volume fraction was selected. To enhance the proliferation resistance and actinide transmutation, all the transuranic (TRU) elements recovered from light water reactor spent fuel were used in a ternary alloy form of U-TRU-10Zr. A 125 MWt core design was developed, for which the burnup reactivity swing was only 1.6$ over the 30-year core lifetime. The average discharge burnup was 87 MWd/kg, and the maximum sodium void worth was 4.65$. The evaluated reactivity coefficients provided sufficient negative feedbacks. Shutdown margins of control systems were confirmed. Steady-state thermal-hydraulic analysis results showed that peak 2{sigma} cladding inner-wall and fuel centerline temperatures were less than design limits with sufficient margins. Detailed transient analyses for the total loss of power to reactor and intermediate coolant pumps showed that no fuel damage or cladding failure would occur, even when multiple safety systems were assumed to malfunction. (authors)

  18. Computational Design of Strain in Core-Shell Nanoparticles for Optimizing Catalytic Activity.

    PubMed

    Moseley, Philip; Curtin, W A

    2015-06-10

    Surface strains in core-shell nanoparticles modify catalytic activity. Here, a continuum-based strategy enables accurate surface-strain-based screening and design of core-shell systems using minimal input as a means to enhance catalytic activity. The approach is validated here for Pt shells on CuxPt(1-x) cores and used to interpret experimental results on the oxygen reduction reaction in the same system. The analysis shows that precise control of particle sizes and shell thicknesses is required to achieve peak activity, rationalizing the limited increases in activity observed in experiments. The method is also applied to core-shell nanorods to demonstrate its wide applicability. PMID:25965405

  19. Research advances in polymer emulsion based on "core-shell" structure particle design.

    PubMed

    Ma, Jian-zhong; Liu, Yi-hong; Bao, Yan; Liu, Jun-li; Zhang, Jing

    2013-09-01

    In recent years, quite many studies on polymer emulsions with unique core-shell structure have emerged at the frontier between material chemistry and many other fields because of their singular morphology, properties and wide range of potential applications. Organic substance as a coating material onto either inorganic or organic internal core materials promises an unparalleled opportunity for enhancement of final functions through rational designs. This contribution provides a brief overview of recent progress in the synthesis, characterization, and applications of both inorganic-organic and organic-organic polymer emulsions with core-shell structure. In addition, future research trends in polymer composites with core-shell structure are also discussed in this review. PMID:23726300

  20. Advanced BWR core component designs and the implications for SFD analysis

    SciTech Connect

    Ott, L.J.

    1997-02-01

    Prior to the DF-4 boiling water reactor (BWR) severe fuel damage (SFD) experiment conducted at the Sandia National Laboratories in 1986, no experimental data base existed for guidance in modeling core component behavior under postulated severe accident conditions in commercial BWRs. This paper will present the lessons learned from the DF-4 experiment (and subsequent German CORA BWR SFD tests) and the impact on core models in the current generation of SFD codes. The DF-4 and CORA BWR test assemblies were modeled on the core component designs circa 1985; that is, the 8 x 8 fuel assembly with two water rods and a cruciform control blade constructed of B{sub 4}C-filled tubelets. Within the past ten years, the state-of-the-art with respect to BWR core component development has out-distanced the current SFD experimental data base and SFD code capabilities. For example, modern BWR control blade design includes hafnium at the tips and top of each control blade wing for longer blade operating lifetimes; also water rods have been replaced by larger water channels for better neutronics economy; and fuel assemblies now contain partial-length fuel rods, again for better neutronics economy. This paper will also discuss the implications of these advanced fuel assembly and core component designs on severe accident progression and on the current SFD code capabilities.

  1. Use of Solid Hydride Fuel for Improved long-Life LWR Core Designs

    SciTech Connect

    Greenspan, E

    2006-04-30

    The primary objective of this project was to assess the feasibility of improving the performance of PWR and BWR cores by using solid hydride fuels instead of the commonly used oxide fuel. The primary measure of performance considered is the bus-bar cost of electricity (COE). Additional performance measures considered are safety, fuel bundle design simplicity – in particular for BWR’s, and plutonium incineration capability. It was found that hydride fuel can safely operate in PWR’s and BWR’s without restricting the linear heat generation rate of these reactors relative to that attainable with oxide fuel. A couple of promising applications of hydride fuel in PWR’s and BWR’s were identified: (1) Eliminating dedicated water moderator volumes in BWR cores thus enabling to significantly increase the cooled fuel rods surface area as well as the coolant flow cross section area in a given volume fuel bundle while significantly reducing the heterogeneity of BWR fuel bundles thus achieving flatter pin-by-pin power distribution. The net result is a possibility to significantly increase the core power density – on the order of 30% and, possibly, more, while greatly simplifying the fuel bundle design. Implementation of the above modifications is, though, not straightforward; it requires a design of completely different control system that could probably be implemented only in newly designed plants. It also requires increasing the coolant pressure drop across the core. (2) Recycling plutonium in PWR’s more effectively than is possible with oxide fuel by virtue of a couple of unique features of hydride fuel – reduced inventory of U-238 and increased inventory of hydrogen. As a result, the hydride fuelled core achieves nearly double the average discharge burnup and the fraction of the loaded Pu it incinerates in one pass is double that of the MOX fuel. The fissile fraction of the Pu in the discharged hydride fuel is only ~2/3 that of the MOX fuel and the discharged hydride fuel is more proliferation resistant. Preliminary feasibility assessment indicates that by replacing some of the ZrH1.6 by ThH2 it will be possible to further improve the plutonium incineration capability of PWR’s. Other possibly promising applications of hydride fuel were identified but not evaluated in this work. A number of promising oxide fueled PWR core designs were also found as spin-offs of this study: (1) The optimal oxide fueled PWR core design features smaller fuel rod diameter of D=6.5 mm and a larger pitch-to-diameter ratio of P/D=1.39 than presently practiced by industry – 9.5mm and 1.326. This optimal design can provide a 30% increase in the power density and a 24% reduction in the cost of electricity (COE) provided the PWR could be designed to have the coolant pressure drop across the core increased from the reference 29 psia to 60 psia. (2) Using wire wrapped oxide fuel rods in hexagonal fuel assemblies it is possible to design PWR cores to operate at 54% higher power density than the reference PWR design that uses grid spacers and a square lattice, provided 60 psia coolant pressure drop across the core could be accommodated. Uprating existing PWR’s to use such cores could result in 40% reduction in the COE. The optimal lattice geometry is D = 8.08 mm and P/D = 1.41. The most notable advantages of wire wraps over grid spacers are their significant lower pressure drop, higher critical heat flux and improved vibrations characteristics.

  2. Designing high frequency ac inductors using ferrite and Molypermalloy Powder Cores (MPP)

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.; Wagner, A. P.

    1985-01-01

    The major considerations in the design of high frequency ac inductors are reviewed. Two methods for designing the inductor: the area product method and the core geometry method, are presented. The two major effects of the inductor air gap, fringing flux power loss and increase of inductance, are discussed. Equations for the inductor design and a step-by-step design procedure are given. The use of a lumped air gap or a distributed air gap are discussed and a comparison of the losses resulting from these gaps, together with experimental results are presented.

  3. Verifying IP-Core based System-On-Chip Designs Pankaj Chauhan, Edmund M. Clarke, Yuan Lu and Dong Wang

    E-print Network

    Clarke, Edmund M.

    Verifying IP-Core based System-On-Chip Designs Pankaj Chauhan, Edmund M. Clarke, Yuan Lu and Dong and for all, the standard bus interconnecting IP Cores in the system . The next task is to verify the glue logic, which connects the IP Cores to the buses. Finally, using the verified bus protocols and the IP

  4. Design and Realization of Embedded General Intelligent Controller Based on Microprocessor with ARM Core

    Microsoft Academic Search

    Qian Zhang; Qiusheng Zheng; Guoqiang Wang

    2007-01-01

    The realization method of designing a sort of controller based on microprocessor with ARM core was discussed in this paper, and the project of adopting intelligent control algorithm library as control strategy of embedded intelligent controller was proposed, a kind of improved single NN-PID control algorithm and a human-simulation intelligent control algorithm were given, too. The hardware circuit and structure

  5. Narrative Plus: Designing and Implementing the Common Core State Standards with the Gift Essay

    ERIC Educational Resources Information Center

    Chandler-Olcott, Kelly; Zeleznik, John

    2013-01-01

    The authors of this article describe their inquiry into implementation of the writing-focused Common Core State Standards in a co-taught English 9 class in an urban school. They describe instructional moves designed to increase student success with an assignment called the Gift Essay, with particular focus on planning and other organizational…

  6. Scan chain design for test time reduction in core-based ICs

    Microsoft Academic Search

    Joep Aerts; Erik Jan Marinissen

    1998-01-01

    The size of the test vector set forms a significant factor in the overall production costs of ICs, as it defines the test application time and the required pin memory size of the test equipment. Large core-based ICs often require a very large test vector set for a high test coverage. This paper deals with the design of scan chains

  7. Designing Scalable FPGA-Based Reduction Circuits Using Pipelined Floating-Point Cores

    E-print Network

    Prasanna, Viktor K.

    Designing Scalable FPGA-Based Reduction Circuits Using Pipelined Floating-Point Cores Ling Zhuo California Los Angeles, CA 90089-2562 {lzhuo,grm,prasanna}@usc.edu Abstract The use of pipelined floating associated with pipelined floating-point reduction circuits can limit the scalabil- ity or severely reduce

  8. Spring design for use in the core of a nuclear reactor

    DOEpatents

    Willard, Jr., H. James (Bethel Park, PA)

    1993-01-01

    A spring design particularly suitable for use in the core of a nuclear reactor includes one surface having a first material oriented in a longitudinal direction, and another surface having a second material oriented in a transverse direction. The respective surfaces exhibit different amounts of irraditation induced strain.

  9. Core Curriculum / 18 credits IS 6420 Database Theory and Design 3

    E-print Network

    Tipple, Brett

    Core Curriculum / 18 credits IS 6420 Database Theory and Design 3 IS 6410 Information Systems Analytics 3 IS 6571 IT Forensics 3 IS 6570 IT Security 3 ACCTG 6520 IT Risks and Controls 3 The MSIS program ­ Fall, Spring and Summer semesters MASTER OF SCIENCE IN INFORMATION SYSTEMS MSIS801-581-7785 / 877

  10. Design and Implementation of the National Institute of Environmental Health Sciences Dublin Core Metadata Schema

    Microsoft Academic Search

    W. Davenport Robertson; Ellen M. Leadem; Jed Dube; Jane Greenberg

    2001-01-01

    The National Institute of Environmental Health Sciences (NIEHS) has formed a team to design and implement a Dublin Core-based metadata schema to enhance the public's ability to retrieve pertinent public health information on the organization's Web site. The team decided to use the DC schema because it is a de facto standard and because of its flexibility. With a little

  11. Coarse-grained parallel genetic algorithm applied to a nuclear reactor core design optimization problem

    Microsoft Academic Search

    Cláudio M. N. A. Pereira; Celso M. F. Lapa

    2003-01-01

    This work extends the research related to genetic algorithms (GA) in core design optimization problems, which basic investigations were presented in previous work. Here we explore the use of the Island Genetic Algorithm (IGA), a coarse-grained parallel GA model, comparing its performance to that obtained by the application of a traditional non-parallel GA. The optimization problem consists on adjusting several

  12. AMPLIFIER DESIGN IMPLEMENTING HOLLOW-CORE PHOTONIC BANDGAP FIBER FOR FIBER-LASER BASED

    E-print Network

    Washburn, Brian

    AMPLIFIER DESIGN IMPLEMENTING HOLLOW-CORE PHOTONIC BANDGAP FIBER FOR FIBER-LASER BASED INFRARED-locked erbium-doped fiber lasers typically require an external amplifier since the pulses directly from signal to locking electronics Amplifier HNLF Mode-locked fiber laser Amplifier HNLF Mode-locked fiber

  13. AMPLIFIER DESIGN IMPLEMENTING HOLLOW-CORE PHOTONIC BANDGAP FIBER FOR FIBER-LASER BASED INFRARED

    E-print Network

    Washburn, Brian

    AMPLIFIER DESIGN IMPLEMENTING HOLLOW-CORE PHOTONIC BANDGAP FIBER FOR FIBER-LASER BASED INFRARED-doped fiber lasers typically require an external amplifier since the pulses directly from the laser have Mode-locked erbium-doped fiber lasers produce the ideal frequency comb for infrared optical frequency

  14. Design of a 64-bit, 100 MIPS microprocessor core IC for hybrid CMOS-SEED technology

    Microsoft Academic Search

    F. E. Kiamilev; J. S. Lambirth; R. G. Rozier; A. V. Krishnamoorthy

    1996-01-01

    We describe the design of a hybrid CMOS-SEED 64-bit microprocessor core IC with 192 optical I\\/Os. This 3.5 mm2 IC was fabricated and electrically tested at 100 MHz with a performance of 100 million 64-bit instructions per second (MIPS). The processor design includes a 64-bit arithmetic-logic unit (ALU) which implements 16 logic and 32 fixed-point arithmetic functions. A 1 cm2

  15. Experimental ferrite core circuit analysis and design applied to an analog/digital converter 

    E-print Network

    Hughes, Robert William

    1965-01-01

    EXPKRflIENTAL FERRITE CORE CIRCUIT ANALYSIS A/4i) CESIGN APPLI ED' TO AN ANALOG+I QITAL -CCWERTER I I 'O' Thaaka RCSERT, NI. LL'I AN HQQAKS:-. , ";, , '. . :. . '. -:. '"":, , ':-. ', . -' ". ' t, . I I I' I, ' . Sobalttad, ta tb ~ Qra... , Na'fir. Sabjaat& ' Eiaktr leal EnCInaaring . EXPERIIIENTAL FERRITE CORE CIRCUIT ANALYSIS AND DESIGN APPLIED TO 'AN AMALGG/DIGITAL CONVERTER f 1 A, . Thea I'a t ROBERT Wl LI. I Al'Jl. HUGHES (Goober, ) ' (Me@bar) ' A'yprived . a'o . . to a4...

  16. Safety and core design of large liquid-metal cooled fast breeder reactors

    NASA Astrophysics Data System (ADS)

    Qvist, Staffan Alexander

    In light of the scientific evidence for changes in the climate caused by greenhouse-gas emissions from human activities, the world is in ever more desperate need of new, inexhaustible, safe and clean primary energy sources. A viable solution to this problem is the widespread adoption of nuclear breeder reactor technology. Innovative breeder reactor concepts using liquid-metal coolants such as sodium or lead will be able to utilize the waste produced by the current light water reactor fuel cycle to power the entire world for several centuries to come. Breed & burn (B&B) type fast reactor cores can unlock the energy potential of readily available fertile material such as depleted uranium without the need for chemical reprocessing. Using B&B technology, nuclear waste generation, uranium mining needs and proliferation concerns can be greatly reduced, and after a transitional period, enrichment facilities may no longer be needed. In this dissertation, new passively operating safety systems for fast reactors cores are presented. New analysis and optimization methods for B&B core design have been developed, along with a comprehensive computer code that couples neutronics, thermal-hydraulics and structural mechanics and enables a completely automated and optimized fast reactor core design process. In addition, an experiment that expands the knowledge-base of corrosion issues of lead-based coolants in nuclear reactors was designed and built. The motivation behind the work presented in this thesis is to help facilitate the widespread adoption of safe and efficient fast reactor technology.

  17. Fuel and Core Design for Long Operating Cycle Simplified BWR (LSBWR)

    SciTech Connect

    Noriyuki Yoshida; Kouji Hiraiwa; Mikihide Nakamaru; Hideaki Heki [Toshiba Corporation, Isogo Nuclear Engineering Center, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan)

    2002-07-01

    This paper describes an innovative core concept currently being developed for long operating cycle simplified BWR (LSBWR). The LSBWR adopts the long cycle operation (15 years) for the elimination of the fuel pool and the refueling machines and for the capacity usage ratio improvement. To achieve long cycle operation, a combination of enriched gadolinium and 0.7- times sized small bundle with peripheral-positioned gadolinium rod is adopted as a key design concept. A nuclear design for fuel bundle has been determined based on three dimensional nuclear and thermal hydraulic calculation. A core performance has been evaluated based on this bundle design and thermal performance and reactivity characteristics indicated preferable value. (authors)

  18. A low overhead design for testability and test generation technique for core-based systems-on-a-chip

    Microsoft Academic Search

    Indradeep Ghosh; Niraj K. Jha; Sujit Dey

    1999-01-01

    In a fundamental paradigm shift in system design, entire systems are being built on a single chip, using multiple embedded cores. Though the newest system design methodology has several advantages in terms of time-to-market and system cost, testing such core-based systems is difficult, mainly due to the problem of justifying test sequences at the inputs of a core embedded deep

  19. Insert Design and Manufacturing for Foam-Core Composite Sandwich Structures

    NASA Astrophysics Data System (ADS)

    Lares, Alan

    Sandwich structures have been used in the aerospace industry for many years. The high strength to weight ratios that are possible with sandwich constructions makes them desirable for airframe applications. While sandwich structures are effective at handling distributed loads such as aerodynamic forces, they are prone to damage from concentrated loads at joints or due to impact. This is due to the relatively thin face-sheets and soft core materials typically found in sandwich structures. Carleton University's Uninhabited Aerial Vehicle (UAV) Project Team has designed and manufactured a UAV (GeoSury II Prototype) which features an all composite sandwich structure fuselage structure. The purpose of the aircraft is to conduct geomagnetic surveys. The GeoSury II Prototype serves as the test bed for many areas of research in advancing UAV technologies. Those areas of research include: low cost composite materials manufacturing, geomagnetic data acquisition, obstacle detection, autonomous operations and magnetic signature control. In this thesis work a methodology for designing and manufacturing inserts for foam-core sandwich structures was developed. The results of this research work enables a designer wishing to design a foam-core sandwich airframe structure, a means of quickly manufacturing optimized inserts for the safe introduction of discrete loads into the airframe. The previous GeoSury II Prototype insert designs (v.1 & v.2) were performance tested to establish a benchmark with which to compare future insert designs. Several designs and materials were considered for the new v.3 inserts. A plug and sleeve design was selected, due to its ability to effectively transfer the required loads to the sandwich structure. The insert material was chosen to be epoxy, reinforced with chopped carbon fibre. This material was chosen for its combination of strength, low mass and also compatibility with the face-sheet material. The v.3 insert assembly is 60% lighter than the previous insert designs. A casting process for manufacturing the v.3 inserts was developed. The developed casting process, when producing more than 13 inserts, becomes more economical than machining. An exploratory study was conducted looking at the effects of dynamic loading on the v.3 insert performance. The results of this study highlighted areas for improving dynamic testing of foam-core sandwich structure inserts. Correlations were developed relating design variables such as face-sheet thickness and insert diameter to a failure load for different load cases. This was done through simulations using Computer Aided Engineering (CAE) software, and experimental testing. The resulting correlations were integrated into a computer program which outputs the required insert dimensions given a set of design parameters, and load values.

  20. Performance of truss panels with kagome cores and design of a high authority shape morphing structure

    NASA Astrophysics Data System (ADS)

    Wang, Ju

    This dissertation includes two parts: First, the performance of a light weight truss panels with Kagome cores; Second, design of a high authority morphing structure for hinging and twisting. The performance characteristics of a truss core sandwich panel design based on the 3D Kagome are measured and compared with earlier numerical simulations and the consistency is demonstrated. Panels are fabricated by investment casting and tested in compression, shear and 3-point bending. The isotropic nature of this core design is confirmed. The superior performance relative to truss designs based on the tetrahedron is demonstrated and attributed to the greater resistance to plastic buckling at the equivalent core density. The failed samples are examined in the scanning electron microscope and imperfections are identified to have caused the premature failures. A concept for a high authority shape morphing plate is described. The design incorporates an active Kagome back-plane capable of changing the shape of a solid face by transmitting loads through a tetrahedral core. The two shape deformations to be achieved and demonstrated consist of hinging and twisting. The design is performed by a combination of analytic estimation and numerical simulation, guided by previous assessments of the Kagome configuration. The objective is to ascertain designs that provide the maximum edge displacement subjected to specified passive load. An optimization is used to ascertain the largest displacement achievable within the force capacity of the actuators. These displacements have been demonstrated and shown to correspond with values predicted by numerical simulation. Non-linear effects, such as face wrinkling, are probed by using a finite element method and the fidelity of the results assessed through comparison with measurements. The numerical results are used to validate a dimensional analysis of trends in the actuation resistance of the structure with geometry, as well as the passive load capacity. The forces determined by such analysis are combined with the failure mechanisms for all sub-systems to establish the constraints. The important domains are visualized using mechanism maps. An optimization is used to generate load capacity maps that guide geometric design and provide actuator capacity requirements.

  1. RELAP5 model for advanced neutron source reactor thermal-hydraulic transients, three-element-core design

    SciTech Connect

    Chen, N.C.J.; Wendel, M.W.; Yoder, G.L.

    1996-02-01

    In order to utilize reduced enrichment fuel, the three-element-core design has been proposed. The proposed core configuration consists of inner, middle, and outer elements, with the middle element offset axially beneath the inner and outer elements, which are axially aligned. The three-element-core RELAP5 model assumes that the reactor hardware is changed only within the core region, so that the loop piping, heat exchangers, and pumps remain as assumed for the two-element-core configuration. However, the total flow rate through the core is greater and the pressure drop across the core is less so that the primary coolant pumps and heat exchangers are operating at a different point in their performance curves. This report describes the new RELAP5 input for the core components.

  2. Advanced neutron source reactor conceptual safety analysis report, three-element-core design: Chapter 15, accident analysis

    SciTech Connect

    Chen, N.C.J.; Wendel, M.W.; Yoder, G.L.; Harrington, R.M.

    1996-02-01

    In order to utilize reduced enrichment fuel, the three-element-core design for the Advanced Neutron Source has been proposed. The proposed core configuration consists of inner, middle, and outer elements, with the middle element offset axially beneath the inner and outer elements, which are axially aligned. The three-element-core RELAP5 model assumes that the reactor hardware is changed only within the core region, so that the loop piping, heat exchangers, and pumps remain as assumed for the two-element-core configuration. To assess the impact of changes in the core region configuration and the thermal-hydraulic steady-state conditions, the safety analysis has been updated. This report gives the safety margins for the loss-of-off-site power and pressure-boundary fault accidents based on the RELAP5 results. AU margins are greater for the three-element-core simulations than those calculated for the two-element core.

  3. Advanced Core Design And Fuel Management For Pebble-Bed Reactors

    SciTech Connect

    Hans D. Gougar; Abderrafi M. Ougouag; William K. Terry

    2004-10-01

    A method for designing and optimizing recirculating pebble-bed reactor cores is presented. At the heart of the method is a new reactor physics computer code, PEBBED, which accurately and efficiently computes the neutronic and material properties of the asymptotic (equilibrium) fuel cycle. This core state is shown to be unique for a given core geometry, power level, discharge burnup, and fuel circulation policy. Fuel circulation in the pebble-bed can be described in terms of a few well?defined parameters and expressed as a recirculation matrix. The implementation of a few heat?transfer relations suitable for high-temperature gas-cooled reactors allows for the rapid estimation of thermal properties critical for safe operation. Thus, modeling and design optimization of a given pebble-bed core can be performed quickly and efficiently via the manipulation of a limited number key parameters. Automation of the optimization process is achieved by manipulation of these parameters using a genetic algorithm. The end result is an economical, passively safe, proliferation-resistant nuclear power plant.

  4. Design assumptions and bases for small D-T-fueled Sperical Tokamak (ST) fusion core

    SciTech Connect

    Peng, Y.K.M.; Galambos, J.D.; Fogarty, P.J. [and others

    1996-12-31

    Recent progress in defining the assumptions and clarifying the bases for a small D-T-fueled ST fusion core are presented. The paper covers several issues in the physics of ST plasmas, the technology of neutral beam injection, the engineering design configuration, and the center leg material under intense neutron irradiation. This progress was driven by the exciting data from pioneering ST experiments, a heightened interest in proof-of-principle experiments at the MA level in plasma current, and the initiation of the first conceptual design study of the small ST fusion core. The needs recently identified for a restructured fusion energy sciences program have provided a timely impetus for examining the subject of this paper. Our results, though preliminary in nature, strengthen the case for the potential realism and attractiveness of the ST approach.

  5. Design of broadband dispersion compensating fiber with the small core photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Wu, Ming; Liu, Hairong; Huang, Dexiu; Tong, Weijun; Wei, Huifeng

    2007-11-01

    This paper has presented a design of dispersion compensating fiber with small core photonic crystal fiber (PCF) based on pure silica. The designed small core PCF can be controlled the dispersion properties in terms of the structural parameters, the pitch ? and the air-filling fraction d/?. The negative chromatic dispersion coefficient can be achieved - 586.5ps/(nmÂ.km) at ?=1550nm with ?=0.9?m and d/?=0.9. This kind of PCF can be used for broadband dispersion compensation in S+C+L band (1460-1565nm) and the chromatic dispersion coefficient is lower than -450ps/(nmÂ.km) in S+C+L band. It can realize the dispersion slope compensation because that it exhibits a negative dispersion slope.

  6. Nonlinear CA Based Scalable Design of On-Chip TPG for Multiple Cores

    Microsoft Academic Search

    Sukanta Das; Biplab K. Sikdar; Parimal Pal Chaudhuri

    2004-01-01

    This paper reports an efficient design of test pattern generators (TPGs) for a chip having multiple cores. It is built around nonlinear cellular automata (CA) based pseudo-random pattern generator (PRPG). The modular and cascadable structure of proposed n-cell PRPG can be utilized to construct the (n+1)-cell PRPG without sacrificing the pseudo-randomness quality. The efficiency of such a scalable PRPG structure

  7. Test Planning and Design Space Exploration in a Core-Based Environment

    Microsoft Academic Search

    Erika Cota; Luigi Carro; Marcelo Lubaszewski; Alex Orailoglu

    2002-01-01

    This paper proposes a comprehensive model for testplanning in a core-based environment. The main contributionof this work is the use of several types of TAMs and theconsideration of different optimization factors (area, pinsand test time) during the global TAM and test schedule definition.This expansion of concerns makes possible an efficientyet fine-grained search in the huge design space ofa reuse-based environment.

  8. Design optimization of radially magnetized, iron-cored, tubular permanent-magnet machines and drive systems

    Microsoft Academic Search

    Jiabin Wang; David Howe

    2004-01-01

    In this paper we deduce, from analytical field solutions, the influence of leading design parameters on the performance of a radially magnetized, iron-cored, tubular permanent-magnet machine and its drive system. We derive analytical formulas for predicting the open-circuit electromotive force, the thrust force, the iron loss, and the winding resistance and inductances, as well as the converter losses. The force

  9. Design, synthesis and photochemical properties of the first examples of iminosugar clusters based on fluorescent cores

    PubMed Central

    Lepage, Mathieu L; Mirloup, Antoine; Ripoll, Manon; Stauffert, Fabien; Bodlenner, Anne

    2015-01-01

    Summary The synthesis and photophysical properties of the first examples of iminosugar clusters based on a BODIPY or a pyrene core are reported. The tri- and tetravalent systems designed as molecular probes and synthesized by way of Cu(I)-catalysed azide–alkyne cycloadditions are fluorescent analogues of potent pharmacological chaperones/correctors recently reported in the field of Gaucher disease and cystic fibrosis, two rare genetic diseases caused by protein misfolding.

  10. Design and measurement of all-rod terahertz photonic crystal fiber with air-core

    NASA Astrophysics Data System (ADS)

    Zhang, Le; Li, Jiu-sheng

    2015-06-01

    An all-rod terahertz wave air-core photonic crystal fiber is designed and fabricated. Transmission spectra through the sample are measured by using terahertz time-domain spectroscopy system. Periodic transmission band and low loss of the fiber are experimentally proved. Measurement results show that the power loss of the present terahertz wave photonic crystal fiber is less than 1.9 dB/cm in transmission bands. The wave confinement ability of the fiber is also demonstrated.

  11. Parametric design and manufacture of transfer port cores for experimental cylinder block castings

    Microsoft Academic Search

    J. Mccartney; R. Kenny

    1989-01-01

    The parametric approach to creating designs from a generalised model is discussed. The technique is extended to the manufacture of transfer port cores for two-stroke internal combustion engines. Bi-cubic patches representing each of the three-dimensional sides of the transfer port are constructed from a parametric model using the minimum amount of information. A postprocessor then creates a CNC program from

  12. Low-Power Design of 90-nm SuperH Processor Core

    Microsoft Academic Search

    Tetsuya Yamada; Masahide Abe; Yusuke Nitta; Kenji Ogura; Manabu Kusaoke; Makoto Ishikawa; Motokazu Ozawa; Kiwamu Takada; Fumio Arakawa; Osamu Nishii; Toshihiro Hattori

    2005-01-01

    A low-power SuperH™ embedded processor core, the SH-X2, has been designed in 90-nm CMOS technology. The power consumption was reduced by using hierarchical fine-grained clock gating to reduce the power consumption of the flip-flops and clock-tree, synthesis and a layout that support implementation of the clock gating, and several-level power evaluations for RTL refinement. With this clock gating and RTL

  13. Energy Efficient Engine integrated core/low spool design and performance report

    NASA Technical Reports Server (NTRS)

    Stearns, E. Marshall

    1985-01-01

    The Energy Efficient Engine (E3) is a NASA program to create fuel saving technology for future transport aircraft engines. The E3 technology advancements were demonstrated to operate reliably and achieve goal performance in tests of the Integrated Core/Low Spool vehicle. The first build of this undeveloped technology research engine set a record for low fuel consumption. Its design and detailed test results are herein presented.

  14. Resource allocation and test scheduling for concurrent test of core-based SOC design

    Microsoft Academic Search

    Yu Huang; Wu-Tung Cheng; Chien-Chung Tsai; Nilanjan Mukherjee; Omer Samman; Yahya Zaidan; Sudhakar M. Reddy

    2001-01-01

    A method to solve the resource allocation and test scheduling problems together in order to achieve concurrent test for core-based system-on-chip (SOC) designs is presented in this paper. The primary objective for concurrent SOC test is to reduce test application time. The methodology used in this paper is not limited to any specific test access mechanism (TAM). Additionally, it can

  15. A Metropolis algorithm combined with Nelder–Mead Simplex applied to nuclear reactor core design

    Microsoft Academic Search

    Wagner F. Sacco; Hermes Alves Filho; Nélio Henderson; Cassiano R. E. de Oliveira

    2008-01-01

    A hybridization of the recently introduced Particle Collision Algorithm (PCA) and the Nelder–Mead Simplex algorithm is introduced and applied to a core design optimization problem which was previously attacked by other metaheuristics. The optimization problem consists in adjusting several reactor cell parameters, such as dimensions, enrichment and materials, in order to minimize the average peak-factor in a three-enrichment-zone reactor, considering

  16. Preliminary design report for SCDAP/RELAP5 lower core plate model

    SciTech Connect

    Coryell, E.W. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Griffin, F.P. [Oak Ridge National Lab., TN (United States)

    1998-07-01

    The SCDAP/RELAP5 computer code is a best-estimate analysis tool for performing nuclear reactor severe accident simulations. Under primary sponsorship of the US Nuclear Regulatory Commission (NRC), Idaho National Engineering and Environmental Laboratory (INEEL) is responsible for overall maintenance of this code and for improvements for pressurized water reactor (PWR) applications. Since 1991, Oak Ridge National Laboratory (ORNL) has been improving SCDAP/RELAP5 for boiling water reactor (BWR) applications. The RELAP5 portion of the code performs the thermal-hydraulic calculations for both normal and severe accident conditions. The structures within the reactor vessel and coolant system can be represented with either RELAP5 heat structures or SCDAP/RELAP5 severe accident structures. The RELAP5 heat structures are limited to normal operating conditions (i.e., no structural oxidation, melting, or relocation), while the SCDAP portion of the code is capable of representing structural degradation and core damage progression that can occur under severe accident conditions. DCDAP/RELAP5 currently assumes that molten material which leaves the core region falls into the lower vessel head without interaction with structural materials. The objective of this design report is to describe the modifications required for SCDAP/RELAP5 to treat the thermal response of the structures in the core plate region as molten material relocates downward from the core, through the core plate region, and into the lower plenum. This has been a joint task between INEEL and ORNL, with INEEL focusing on PWR-specific design, and ORNL focusing upon the BWR-specific aspects. Chapter 2 describes the structures in the core plate region that must be represented by the proposed model. Chapter 3 presents the available information about the damage progression that is anticipated to occur in the core plate region during a severe accident, including typical SCDAP/RELAP5 simulation results. Chapter 4 provides a description of the implementation of the recommended model and Chapter 5 discusses the testing which could be done to verify the design and implementation of the model.

  17. Evaluation for 4S core nuclear design method through integration of benchmark data

    SciTech Connect

    Nagata, A.; Tsuboi, Y. [Advanced System Design and Engineering Dept., Isogo Nuclear Engineering Center, Toshiba Corporation, 8, Shinsugita-Cho, Isogo-ku, Yokohama, 235-8523 (Japan); Moriki, Y. [Power and Industrial Systems Research and Development Center, Toshiba Corporation, 8, Shinsugita-Cho, Isogo-ku, Yokohama, 235-8523 (Japan); Kawashima, M. [Nuclear Technology Application Dept., Toshiba Nuclear Engineering Services Corporation, 8, Shinsugita-Cho, Isogo-ku, Yokohama, 235-8523 (Japan)

    2012-07-01

    The 4S is a sodium-cooled small fast reactor which is reflector-controlled for operation through core lifetime about 30 years. The nuclear design method has been selected to treat neutron leakage with high accuracy. It consists of a continuous-energy Monte Carlo code, discrete ordinate transport codes and JENDL-3.3. These two types of neutronic analysis codes are used for the design in a complementary manner. The accuracy of the codes has been evaluated by analysis of benchmark critical experiments and the experimental reactor data. The measured data used for the evaluation is critical experimental data of the FCA XXIII as a physics mockup assembly of the 4S core, FCA XVI, FCA XIX, ZPR, and data of experimental reactor JOYO MK-1. Evaluated characteristics are criticality, reflector reactivity worth, power distribution, absorber reactivity worth, and sodium void worth. A multi-component bias method was applied, especially to improve the accuracy of sodium void reactivity worth. As the result, it has been confirmed that the 4S core nuclear design method provides good accuracy, and typical bias factors and their uncertainties are determined. (authors)

  18. Low-Enriched Fuel Design Concept for the Prismatic Very High Temperature Reactor Core

    SciTech Connect

    Sterbentz, James W

    2007-05-01

    A new non-TRISO fuel and clad design concept is proposed for the prismatic, heliumcooled Very High Temperature Reactor core. The new concept could substantially reduce the current 10-20 wt% TRISO uranium enrichments down to 4-6 wt% for both initial and reload cores. The proposed fuel form would be a high-temperature, high-density uranium ceramic, for example UO2, configured into very small diameter cylindrical rods. The small diameter fuel rods significantly increase core reactivity through improved neutron moderation and fuel lumping. Although a high-temperature clad system for the concept remains to be developed, recent success in tube fabrication and preliminary irradiation testing of silicon carbide (SiC) cladding for light water reactor applications offers good potential for this application, and for future development of other carbide clad designs. A high-temperature ceramic fuel, together with a high-temperature clad material, could also lead to higher thermal safety margins during both normal and transient reactor conditions relative to TRISO fuel. The calculated neutronic results show that the lowenrichment, small diameter fuel rods and low thermal neutron absorbing clad retain the strong negative Doppler fuel temperature coefficient of reactivity that ensures inherent safe operation of the VHTR, and depletion studies demonstrate that an 18-month power cycle can be achieved with the lower enrichment fuel.

  19. Dosimetric comparison of four new design 103Pd brachytherapy sources: optimal design using silver and copper rod cores.

    PubMed

    Hosseini, S Hamed; Sadeghi, Mahdi; Ataeinia, Vahideh

    2009-07-01

    Four new brachytherapy sources, IRA1-103Pd, IRA2-103Pd, IRA3-103Pd, and IRA4-103Pd, have been developed at Agricultural, Medical, and Industrial Research School and are designed for permanent implant application. With the goal of determining an optimal design for a 103Pd source, this article compares the dosimetric properties of these sources with reference to the authors' earlier IRA-103Pd source. The four new sources differ in end cap configuration and thickness and in the core material, silver or copper, that carries the adsorbed 103Pd. Dosimetric data derived from the authors' Monte Carlo simulation results are reported in accordance with the updated AAPM Task Group No. 43 report (TG-43U1). For each source, the authors obtained detailed results for the dose rate constant lambda, the radial dose function g(r), the anisotropy function F(r, theta), and the anisotropy factor phi(an)(r). In this study, the optimal source IRA3-103Pd provides the most isotropic dose distribution in water with the dose rate constant of 0.678(+/-0.1%) cGy h(-1) U(-1). The IRA3-103Pd design has a silver rod core combined with thin-wall, concave end caps. Finally, the authors compared the results for their optimal source with published results for those of other source manufacturers. PMID:19673207

  20. Dosimetric comparison of four new design {sup 103}Pd brachytherapy sources: Optimal design using silver and copper rod cores

    SciTech Connect

    Hosseini, S. Hamed; Sadeghi, Mahdi; Ataeinia, Vahideh [Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, P.O. Box 31485-498, Karaj, Tehran (098)21 (Iran, Islamic Republic of)

    2009-07-15

    Four new brachytherapy sources, IRA1-{sup 103}Pd, IRA2-{sup 103}Pd, IRA3-{sup 103}Pd, and IRA4-{sup 103}Pd, have been developed at Agricultural, Medical, and Industrial Research School and are designed for permanent implant application. With the goal of determining an optimal design for a {sup 103}Pd source, this article compares the dosimetric properties of these sources with reference to the authors' earlier IRA-{sup 103}Pd source. The four new sources differ in end cap configuration and thickness and in the core material, silver or copper, that carries the adsorbed {sup 103}Pd. Dosimetric data derived from the authors' Monte Carlo simulation results are reported in accordance with the updated AAPM Task Group No. 43 report (TG-43U1). For each source, the authors obtained detailed results for the dose rate constant {Lambda}, the radial dose function g(r), the anisotropy function F(r,{theta}), and the anisotropy factor {phi}{sub an}(r). In this study, the optimal source IRA3-{sup 103}Pd provides the most isotropic dose distribution in water with the dose rate constant of 0.678({+-}0.1%) cGy h{sup -1} U{sup -1}. The IRA3-{sup 103}Pd design has a silver rod core combined with thin-wall, concave end caps. Finally, the authors compared the results for their optimal source with published results for those of other source manufacturers.

  1. Design of a boiling water reactor equilibrium core using thorium-uranium fuel

    SciTech Connect

    Francois, J-L.; Nunez-Carrera, A.; Espinosa-Paredes, G.; Martin-del-Campo, C.

    2004-10-06

    In this paper the design of a Boiling Water Reactor (BWR) equilibrium core using thorium is presented; a heterogeneous blanket-seed core arrangement concept was adopted. The design was developed in three steps: in the first step two different assemblies were designed based on the integrated blanket-seed concept, they are the blanket-dummy assembly and the blanket-seed assembly. The integrated blanketseed concept comes from the fact that the blanket and the seed rods are located in the same assembly, and are burned-out in a once-through cycle. In the second step, a core design was developed to achieve an equilibrium cycle of 365 effective full power days in a standard BWR with a reload of 104 fuel assemblies designed with an average 235U enrichment of 7.5 w/o in the seed sub-lattice. The main operating parameters, like power, linear heat generation rate and void distributions were obtained as well as the shutdown margin. It was observed that the analyzed parameters behave like those obtained in a standard BWR. The shutdown margin design criterion was fulfilled by addition of a burnable poison region in the assembly. In the third step an in-house code was developed to evaluate the thorium equilibrium core under transient conditions. A stability analysis was also performed. Regarding the stability analysis, five operational states were analyzed; four of them define the traditional instability region corner of the power-flow map and the fifth one is the operational state for the full power condition. The frequency and the boiling length were calculated for each operational state. The frequency of the analyzed operational states was similar to that reported for BWRs; these are close to the unstable region that occurs due to the density wave oscillation phenomena in some nuclear power plants. Four transient analyses were also performed: manual SCRAM, recirculation pumps trip, main steam isolation valves closure and loss of feed water. The results of these transients are similar to those obtained with the traditional UO2 nuclear fuel.

  2. Design of a highly nonlinear liquid-core photonic crystal fiber used for fiber optical parametric amplifiers

    Microsoft Academic Search

    Chao-yang Lee; Dai Juan; Yong-gang Wang; Bo-jun Yang

    2008-01-01

    In this paper, we design a new nonlinear fiber by filling a highly nonlinear liquid into hollow-core photonic crystal fibers. The liquid-core photonic crystal fiber with carbon disulfide exhibits an extremely high nonlinear parameter gamma which can be more than 20 times larger than that of a conventional PCF, which is desired for FOPA. By using Full Vector Finite Element

  3. The ARIES-RS power core -- Recent development in Li/V designs

    SciTech Connect

    Sze, D.K.; Billone, M.C.; Hua, T.Q. [and others

    1997-04-01

    The ARIES-RS fusion power plant design study is based on reversed-shear (RS) physics with a Li/V (lithium breeder and vanadium structure) blanket. The reversed-shear discharge has been documented in many large tokamak experiments. The plasma in the RS mode has a high beta, low current, and low current drive requirements. Therefore, it is an attractive physics regime for a fusion power plant. The blanket system based on a Li/V has high temperature operating capability, good tritium breeding, excellent high heat flux removal capability, long structural life time, low activation, low after heat and good safety characteristics. For these reasons, the ARIES-RS reactor study selected Li/V as the reference blanket. The combination of attractive physics and attractive blanket engineering is expected to result in a superior power plant design. This paper summarizes the power core design of the ARIES-RS power plant study.

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

    SciTech Connect

    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.

  5. Preliminary core design studies for the advanced burner reactor over a wide range of conversion ratios.

    SciTech Connect

    Hoffman, E. A.; Yang, W. S.; Hill, R. N.; Nuclear Engineering Division

    2008-05-05

    A consistent set of designs for 1000 MWt commercial-scale sodium-cooled Advance Burner Reactors (ABR) have been developed for both metal and oxide-fueled cores with conversion ratios from breakeven (CR=1.0) to fertile-free (CR=0.0). These designs are expected to satisfy thermal and irradiation damage limits based on the currently available data. The very low conversion ratio designs require fuel that is beyond the current fuel database, which is anticipated to be qualified by and for the Advanced Burned Test Reactor. Safety and kinetic parameters were calculated, but a safety analysis was not performed. Development of these designs was required to achieve the primary goal of this study, which was to generate representative fuel cycle mass flows for system studies of ABRs as part of the Global Nuclear Energy Partnership (GNEP). There are slight variations with conversion ratio but the basic ABR configuration consists of 144 fuel assemblies and between 9 and 22 primary control assemblies for both the metal and oxide-fueled cores. Preliminary design studies indicated that it is feasible to design the ABR to accommodate a wide range of conversion ratio by employing different assembly designs and including sufficient control assemblies to accommodate the large reactivity swing at low conversion ratios. The assemblies are designed to fit within the same geometry, but the size and number of fuel pins within each assembly are significantly different in order to achieve the target conversion ratio while still satisfying thermal limits. Current irradiation experience would allow for a conversion ratio of somewhat below 0.75. The fuel qualification for the first ABR should expand this experience to allow for much lower conversion ratios and higher bunrups. The current designs were based on assumptions about the performance of high and very high enrichment fuel, which results in significant uncertainty about the details of the designs. However, the basic fuel cycle performance trends such as conversion ratio and mass flow parameters are less sensitive to these parameters and the current results should provide a good basis for static and dynamic system analysis. The conversion ratio is fundamentally a ratio of the macroscopic cross section of U-238 capture to that of TRU fission. Since the microscopic cross sections only change moderately with fuel design and isotopic concentration for the fast reactor, a specific conversion ratio requires a specific enrichment. The approximate average charge enrichment (TRU/HM) is 14%, 21%, 33%, 56%, and 100% for conversion ratios of 1.0, 0.75, 0.50, 0.25, and 0.0 for the metal-fueled cores. The approximate average charge enrichment is 17%, 25%, 38%, 60%, and 100% for conversion ratios of 1.0, 0.75, 0.50, 0.25, and 0.0 for the oxide-fueled core. For the split batch cores, the maximum enrichment will be somewhat higher. For both the metal and oxide-fueled cores, the reactivity feedback coefficients and kinetics parameters seem reasonable. The maximum single control assembly reactivity faults may be too large for the low conversion ratio designs. The average reactivity of the primary control assemblies was increased, which may cause the maximum reactivity of the central control assembly to be excessive. The values of the reactivity coefficients and kinetics parameters show that some values appear to improve significantly at lower conversion ratios while others appear far less favorable. Detailed safety analysis is required to determine if these designs have adequate safety margins or if appropriate design modifications are required. Detailed system analysis data has been generated for both metal and oxide-fueled core designs over the entire range of potential burner reactors. Additional data has been calculated for a few alternative fuel cycles. The systems data has been summarized in this report and the detailed data will be provided to the systems analysis team so that static and dynamic system analyses can be performed.

  6. Design and Analysis of 3D-MAPS: A Many-core 3D Processor with Stacked Memory

    E-print Network

    Lim, Sung Kyu

    Design and Analysis of 3D-MAPS: A Many-core 3D Processor with Stacked Memory Michael B. Healy, Krit--We describe the design and analysis of 3D-MAPS, a 64- core 3D-stacked memory-on-processor running at 277 MHz with 63 GB/s memory bandwidth, sent for fabrication using Tezzaron's 3D stacking technology. We also

  7. Core and System Design of Reduced-Moderation Water Reactor with Passive Safety Features

    SciTech Connect

    Iwamura, Takamichi; Okubo, Tsutomu; Yonomoto, Taisuke [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Ibaraki-ken, 319-1195 (Japan); Takeda, Renzo; Moriya, Kumiaki [Hitachi, Ltd. (Japan); Kanno, Minoru [The Japan Atomic Power Company (Japan)

    2002-07-01

    In order to ensure the sustainable energy supply in Japan, research and developments of reduced-moderation water reactor (RMWR) have been performed. The RMWR can attain the favorable characteristics such as high burn-up, long operation cycle, multiple recycling of plutonium and effective utilization of uranium resources, based on the matured LWR technologies. MOX fuel assemblies in the tight-lattice fuel rod arrangement are used to reduce the moderation of neutron, and hence, to increase the conversion ratio. The conceptual design has been accomplished for the small 330 MWe RMWR core with the discharge burn-up of 60 GWd/t and the operation cycle of 24 months, under the natural circulation cooling of the core. A breeding ratio of 1.01 and the negative void reactivity coefficient are simultaneously realized in the design. In the plant system design, the passive safety features are intended to be utilized mainly to improve the economy. At present, a hybrid one under the combination of the passive and the active components, and a fully passive one are proposed. The former has been evaluated to reduce the cost for the reactor components. (authors)

  8. Design of a Resistively Heated Thermal Hydraulic Simulator for Nuclear Rocket Reactor Cores

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Foote, John P.; Ramachandran, Narayanan; Wang, Ten-See; Anghaie, Samim

    2007-01-01

    A preliminary design study is presented for a non-nuclear test facility which uses ohmic heating to replicate the thermal hydraulic characteristics of solid core nuclear reactor fuel element passages. The basis for this testing capability is a recently commissioned nuclear thermal rocket environments simulator, which uses a high-power, multi-gas, wall-stabilized constricted arc-heater to produce high-temperature pressurized hydrogen flows representative of reactor core environments, excepting radiation effects. Initially, the baseline test fixture for this non-nuclear environments simulator was configured for long duration hot hydrogen exposure of small cylindrical material specimens as a low cost means of evaluating material compatibility. It became evident, however, that additional functionality enhancements were needed to permit a critical examination of thermal hydraulic effects in fuel element passages. Thus, a design configuration was conceived whereby a short tubular material specimen, representing a fuel element passage segment, is surrounded by a backside resistive tungsten heater element and mounted within a self-contained module that inserts directly into the baseline test fixture assembly. With this configuration, it becomes possible to create an inward directed radial thermal gradient within the tubular material specimen such that the wall-to-gas heat flux characteristics of a typical fuel element passage are effectively simulated. The results of a preliminary engineering study for this innovative concept are fully summarized, including high-fidelity multi-physics thermal hydraulic simulations and detailed design features.

  9. CORE ANALYSIS, DESIGN AND OPTIMIZATION OF A DEEP-BURN PEBBLE BED REACTOR

    SciTech Connect

    B. Boer; A. M. Ougouag

    2010-05-01

    Achieving a high burnup in the Deep-Burn pebble bed reactor design, while remaining within the limits for fuel temperature, power peaking and temperature reactivity feedback, is challenging. The high content of Pu and Minor Actinides in the Deep-Burn fuel significantly impacts the thermal neutron energy spectrum. This can result in power and temperature peaking in the pebble bed core in locally thermalized regions near the graphite reflectors. Furthermore, the interplay of the Pu resonances of the neutron absorption cross sections at low-lying energies can lead to a positive temperature reactivity coefficient for the graphite moderator at certain operating conditions. To investigate the aforementioned effects a code system using existing codes has been developed for neutronic, thermal-hydraulic and fuel depletion analysis of Deep-Burn pebble bed reactors. A core analysis of a Deep-Burn Pebble Bed Modular Reactor (400 MWth) design has been performed for two Deep-Burn fuel types and possible improvements of the design with regard to power peaking and temperature reactivity feedback are identified.

  10. Comparison of a NuScale SMR conceptual core design using CASMO5/simulate5 and MCNP5

    SciTech Connect

    Haugh, B. [Studsvik Scandpower Inc., 1015 Ashes Drive, Wilmington, NC 28405 (United States); Mohamed, A. [NuScale Power Inc., 1100 NE Circle Blvd, Corvallis, OR 97330 (United States)

    2012-07-01

    A key issue during the initial start-ups of new Small Modular Reactors (SMRs) is the lack of operational data for reactor model validation. To help better understand the accuracy of the reactor analysis codes CASMO5 and SIMULATE5, higher order comparisons to MCNP5 have been performed. These comparisons are for an initial core conceptual design of the NuScale reactor. The data have been evaluated at Hot Zero Power (HZP) conditions. Comparisons of core reactivity, fuel temperature coefficient (FTC), and moderator temperature coefficients (MTC) have been performed. Comparison results show good agreement between CASMO5/SIMULATE5 and MCNP5 for the conceptual initial core design. (authors)

  11. Nuclear design of a vapor core reactor for space nuclear propulsion

    SciTech Connect

    Dugan, E.T.; Watanabe, Y.; Kuras, S.A.; Maya, I.; Diaz, N.J. (Innovative Nuclear Space Power and Propulsion Institute, University of Florida, Gainesville, Florida 32611 (United States))

    1993-01-15

    Neutronic analysis methodology and results are presented for the nuclear design of a vapor core reactor for space nuclear propulsion. The Nuclear Vapor Thermal Reactor (NVTR) Rocket Engine uses modified NERVA geometry and systems which the solid fuel replaced by uranium tetrafluoride vapor. The NVTR is an intermediate term gas core thermal rocket engine with specific impulse in the range of 1000--1200 seconds; a thrust of 75,000 lbs for a hydrogen flow rate of 30 kg/s; average core exit temperatures of 3100 K to 3400 K; and reactor thermal powers of 1400 to 1800 MW. Initial calculations were performed on epithermal NVTRs using ZrC fuel elements. Studies are now directed at thermal NVTRs that use fuel elements made of C-C composite. The large ZrC-moderated reactors resulted in thrust-to-weight ratios of only 1 to 2; the compact C-C composite systems yield thrust-to-weight ratios of 3 to 5.

  12. Nuclear design of a vapor core reactor for space nuclear propulsion

    NASA Astrophysics Data System (ADS)

    Dugan, Edward T.; Watanabe, Yoichi; Kuras, Stephen A.; Maya, Isaac; Diaz, Nils J.

    1993-01-01

    Neutronic analysis methodology and results are presented for the nuclear design of a vapor core reactor for space nuclear propulsion. The Nuclear Vapor Thermal Reactor (NVTR) Rocket Engine uses modified NERVA geometry and systems which the solid fuel replaced by uranium tetrafluoride vapor. The NVTR is an intermediate term gas core thermal rocket engine with specific impulse in the range of 1000-1200 seconds; a thrust of 75,000 lbs for a hydrogen flow rate of 30 kg/s; average core exit temperatures of 3100 K to 3400 K; and reactor thermal powers of 1400 to 1800 MW. Initial calculations were performed on epithermal NVTRs using ZrC fuel elements. Studies are now directed at thermal NVTRs that use fuel elements made of C-C composite. The large ZrC-moderated reactors resulted in thrust-to-weight ratios of only 1 to 2; the compact C-C composite systems yield thrust-to-weight ratios of 3 to 5.

  13. A new design for post and core restorations implementing positive locking.

    PubMed

    Richter, Ernst-Jürgen; Boldt, Julian; Groth, Sybille; Proff, Peter; Gredes, Tomasz; Rottner, Kurt

    2008-10-01

    The design of a post and core restoration is a trade-off between a series of requirements to achieve stability of the post itself, the surrounding root dentine and the joint between tooth and post, while maintaining a sufficient apical seal of the remaining root canal filling. Post and core restoration systems come in a variety of different designs and dimensions, where each has its specific strength and weakness. With the exception of threaded versions, posts normally rely on either chemical and/or frictional locking between the post and the remaining root. Failure due to fatigue of the joint or root fracture due to overloading of the dentine is a frequent failure mode, especially for posts anchoring removable prostheses. Perforation of the root in an attempt to maximize the post length is a main cause for failure, too. A new design is proposed which uses a short but large diameter post. The risk of decementation is reduced by positive locking. A cavity with an undercut is prepared into the root, into which the post is fitted. Once joined, the post cannot be separated from the tooth without destruction of either the root or the post. The principle of the new design uses preparation tools and a post which is spread at the bottom. A cylindrically prepared hole is re-shaped to a defined inverse taper with the wider diameter at the bottom of the hole. A cylindrical post is inserted and spread at the bottom to a matching shape after placement. A first in vitro test of the stability showed that the positive locking provides at least as good extraction resistance as conventional post without the critical reliance on the luting/bonding agent. PMID:18840064

  14. Optimal design at inner core of the shaped pyramidal truss structure

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Uk; Yang, Dong-Yol

    2013-12-01

    Sandwich material is a type of composite material with lightweight, high strength, good dynamic properties and high bending stiffness-to-weight ratio. This can be found well such structures in the nature (for example, internal structure of bones, plants, etc.). New trend which prefers eco-friendly products and energy efficiency is emerging in industries recently. Demand for materials with high strength and light weight is also increasing. In line with these trends, researches about manufacturing methods of sandwich material have been actively conducted. In this study, a sandwich structure named as "Shaped Pyramidal Truss Structure" is proposed to improve mechanical strength and to apply a manufacturing process suitable for massive production. The new sandwich structure was designed to enhance compressive strength by changing the cross-sectional shape at the central portion of the core. As the next step, optimization of the shape was required. Optimization technique used here was the SZGA(Successive Zooming Genetic Algorithm), which is one of GA(Genetic Algorithm) methods gradually reducing the area of design variable. The objective function was defined as moment of inertia of the cross-sectional shape of the strut. The control points of cubic Bezier curve, which was assumed to be the shape of the cross section, were used as design variables. By using FEM simulation, it was found that the structure exhibited superior mechanical properties compared to the simple design of the prior art.

  15. Melt spreading code assessment, modifications, and application to the EPR core catcher design.

    SciTech Connect

    Farmer, M. T .; Nuclear Engineering Division

    2009-03-30

    The Evolutionary Power Reactor (EPR) is under consideration by various utilities in the United States to provide base load electrical production, and as a result the design is undergoing a certification review by the U.S. Nuclear Regulatory Commission (NRC). The severe accident design philosophy for this reactor is based upon the fact that the projected power rating results in a narrow margin for in-vessel melt retention by external cooling of the reactor vessel. As a result, the design addresses ex-vessel core melt stabilization using a mitigation strategy that includes: (1) an external core melt retention system to temporarily hold core melt released from the vessel; (2) a layer of 'sacrificial' material that is admixed with the melt while in the core melt retention system; (3) a melt plug in the lower part of the retention system that, when failed, provides a pathway for the mixture to spread to a large core spreading chamber; and finally, (4) cooling and stabilization of the spread melt by controlled top and bottom flooding. The overall concept is illustrated in Figure 1.1. The melt spreading process relies heavily on inertial flow of a low-viscosity admixed melt to a segmented spreading chamber, and assumes that the melt mass will be distributed to a uniform height in the chamber. The spreading phenomenon thus needs to be modeled properly in order to adequately assess the EPR design. The MELTSPREAD code, developed at Argonne National Laboratory, can model segmented, and both uniform and nonuniform spreading. The NRC is thus utilizing MELTSPREAD to evaluate melt spreading in the EPR design. MELTSPREAD was originally developed to support resolution of the Mark I containment shell vulnerability issue. Following closure of this issue, development of MELTSPREAD ceased in the early 1990's, at which time the melt spreading database upon which the code had been validated was rather limited. In particular, the database that was utilized for initial validation consisted of: (1) comparison to an analytical solution for the dam break problem, (2) water spreading tests in a 1/10 linear scale model of the Mark I containment by Theofanous et al., and (3) steel spreading tests by Suzuki et al. that were also conducted in a geometry similar to the Mark I. The objective of this work was to utilize the MELTSPREAD code to check the assumption of uniform melt spreading in the EPR core catcher design. As a starting point for the project, the code was validated against the worldwide melt spreading database that emerged after the code was originally written in the very early 1990's. As part of this exercise, the code was extensively modified and upgraded to incorporate findings from these various analytical and experiment programs. In terms of expanding the ability of the code to analyze various melt simulant experiments, the options to input user-specified melt and/or substrate material properties was added. The ability to perform invisicid and/or adiabatic spreading analysis was also added so that comparisons with analytical solutions and isothermal spreading tests could be carried out. In terms of refining the capability to carry out reactor material melt spreading analyses, the code was upgraded with a new melt viscosity model; the capability was added to treat situations in which solid fraction buildup between the liquidus-solidus is non-linear; and finally, the ability to treat an interfacial heat transfer resistance between the melt and substrate was incorporated. This last set of changes substantially improved the predictive capability of the code in terms of addressing reactor material melt spreading tests. Aside from improvements and upgrades, a method was developed to fit the model to the various melt spreading tests in a manner that allowed uncertainties in the model predictions to be statistically characterized. With these results, a sensitivity study was performed to investigate the assumption of uniform spreading in the EPR core catcher that addressed parametric variations in: (1) melt pour mass, (2) melt composition, (3) me

  16. Dynamic analysis of sandwich panels and topological design of cores considering the size effect

    Microsoft Academic Search

    K. Qiu; W. Zhang; P. Duysinx

    A typical sandwich panel is composed of the upper and lower skins separated by a lightweight core, for instance, foams, trusshoneycombs and corrugated cores (1-4). And each kind of cores has various structural forms. For example, the foam cores have polymer and metallic ones with open-cell and close- cell ones; the truss cores have tetrahedral, pyramidal, 3D Kagome and diamond

  17. An Area-Efficient Variable Length Decoder IP Core Design for MPEG1\\/2\\/4 Video Coding Applications

    Microsoft Academic Search

    Chih-Da Chien; Keng-Po Lu; Yu-Min Chen; Jiun-In Guo; Yuan-Sun Chu; Ching-Lung Su

    2006-01-01

    This paper proposes an area-efficient variable length decoder (VLD) IP core design for MPEG-1\\/2\\/4 video coding applications. The proposed IP core exploits the parallel numerical matching in the MPEG-1\\/2\\/4 entropy decoding to achieve high data throughput rate in terms of limited hardware cost. This feature not only improves the performance of VLD, but also facilitates reducing the power consumption through

  18. Core design study of a supercritical light water reactor with double row fuel rods

    SciTech Connect

    Zhao, C.; Wu, H.; Cao, L.; Zheng, Y. [School of Nuclear Science and Technology, Xi'an Jiaotong Univ., No. 28, Xianning West Road, Xi'an, ShannXi, 710049 (China); Yang, J.; Zhang, Y. [China Nuclear Power Technology Research Inst., Yitian Road, ShenZhen, GuangDong, 518026 (China)

    2012-07-01

    An equilibrium core for supercritical light water reactor has been designed. A novel type of fuel assembly with dual rows of fuel rods between water rods is chosen and optimized to get more uniform assembly power distributions. Stainless steel is used for fuel rod cladding and structural material. Honeycomb structure filled with thermal isolation is introduced to reduce the usage of stainless steel and to keep moderator temperature below the pseudo critical temperature. Water flow scheme with ascending coolant flow in inner regions is carried out to achieve high outlet temperature. In order to enhance coolant outlet temperature, the radial power distributions needs to be as flat as possible through operation cycle. Fuel loading pattern and control rod pattern are optimized to flatten power distribution at inner regions. Axial fuel enrichment is divided into three parts to control axial power peak, which affects maximum cladding surface temperature. (authors)

  19. Design, synthesis and biological evaluation of FLT3 covalent inhibitors with a resorcylic acid core.

    PubMed

    Xu, Jin; Ong, Esther H Q; Hill, Jeffrey; Chen, Anqi; Chai, Christina L L

    2014-12-01

    A series of simplified ring-opened resorcylic acid lactone (RAL) derivatives were conveniently synthesized to target FLT3 and its mutants either irreversibly or reversibly. Our design of covalent FLT3 inhibitors is based on cis-enone RALs (e.g., L-783,277) that have a ?-resorcylic acid as the core structure. The designed compounds contain three types of Michael acceptors (acrylamide, vinylsulfonamide and maleimide) as potential covalent traps of a cysteine residue at the binding site of kinases. A variety of functional substitutions were also introduced to maximize the binding interactions. Biological evaluations revealed that compound 17, despite the presence of a highly reactive maleimide Michael acceptor, is a potent covalent FLT3 inhibitor which shows some specificity in cellular assays. On the other hand, compounds 2 and 6 containing acrylamide or vinylsulfonamide groups are reversible towards FLT3 binding, and are potent and selective inhibitors of mutant FLT3-ITD versus wt-FLT3. They also inhibit cell proliferation in FLT3-ITD expressing cell line MV-4-11 as compared to wt-FLT3 expressing cell line THP-1 and non-FLT3 cell lines (K562, HL60 and Hek-293T). PMID:25456387

  20. The design and implementation of the parallel out-of-core ScaLAPACK LU, QR and Cholesky factorization routines

    SciTech Connect

    D`Azevedo, E.F.; Dongarra, J.J.

    1997-04-01

    This paper describes the design and implementation of three core factorization routines--LU, QR and Cholesky--included in the out-of-core extension of ScaLAPACK. These routines allow the factorization and solution of a dense system that is too large to fit entirely in physical memory. An image of the full matrix is maintained on disk and the factorization routines transfer sub-matrices into memory. The left-looking column-oriented variant of the factorization algorithm is implemented to reduce the disk I/O traffic. The routines are implemented using a portable I/O interface and utilize high performance ScaLAPACK factorization routines as in-core computational kernels. The authors present the details of the implementation for the out-of-core ScaLAPACK factorization routines, as well as performance and scalability results on the Intel Paragon.

  1. The fuzzy clearing approach for a niching genetic algorithm applied to a nuclear reactor core design optimization problem

    Microsoft Academic Search

    Wagner F. Sacco; Marcelo D. Machado; Cláudio M. N. A. Pereira; Roberto Schirru

    2004-01-01

    This article extends previous efforts on genetic algorithms (GAs) applied to a core design optimization problem. We introduce the application of a new Niching Genetic Algorithm (NGA) to this problem and compare its performance to these previous works. The optimization problem consists in adjusting several reactor cell parameters, such as dimensions, enrichment and materials, in order to minimize the average

  2. Design of a boiling water reactor core based on an integrated blanket–seed thorium–uranium concept

    Microsoft Academic Search

    Alejandro Núñez-Carrera; Juan Luis François; Cecilia Martín-del-Campo; Gilberto Espinosa-Paredes

    2005-01-01

    This paper is concerned with the design of a boiling water reactor (BWR) equilibrium core using thorium as a nuclear material in an integrated blanket–seed (BS) assembly. The integrated BS concept comes from the fact that the blanket and the seed rods are located in the same assembly, and are burned out in a once-through cycle. The idea behind the

  3. Enhancing the Practicum Experience for Pre-Service Chemistry Teachers through Collaborative CoRe Design with Mentor Teachers

    ERIC Educational Resources Information Center

    Hume, Anne; Berry, Amanda

    2013-01-01

    This paper reports findings from an ongoing study exploring how the Content Representation (CoRe) design can be used as a tool to help chemistry student teachers begin acquiring the professional knowledge required to become expert chemistry teachers. Phase 2 of the study, reported in this paper, investigated how collaboration with school-based…

  4. How to Reduce Power in 3D IC Designs: A Case Study with OpenSPARC T2 Core

    E-print Network

    Lim, Sung Kyu

    packaging and cooling costs. In addition, the power of an IC has a significant impact on its reliabilityHow to Reduce Power in 3D IC Designs: A Case Study with OpenSPARC T2 Core Moongon Jung1 , Taigon as the driving force for 3D ICs, yet there have been few thorough design studies on how to reduce power in 3D ICs

  5. Advanced MOX Core Design Study of Sodium Cooled Reactors in Current Feasibility Study on Commercialized Fast Reactor Cycle Systems in Japan

    SciTech Connect

    Mizuno, T.; Niwa, H. [Japan Nuclear Cycle development institute, O-arai Engineering Center, 4002 Narita-cho, O-arai-machi, Higashi-ibaraki-gun, Ibaraki-ken, 311-1393 (Japan)

    2002-07-01

    The Sodium cooled MOX core design studies are performed with the target burnup of 150 GWd/t and measures against the recriticality issues in core disruptive accidents (CDAs). Four types of core are comparatively studied in viewpoints of core performance and reliability. Result shows that all the types of core satisfy the target and that the homogeneous core with axial blanket partial elimination subassembly is the most superior concept in case the effectiveness of measures against recriticality issues by the axial blanket partial elimination is assured. (authors)

  6. Measurements of the impedance matrix of a thermoacoustic core: applications to the design of thermoacoustic engines.

    PubMed

    Bannwart, Flávio C; Penelet, Guillaume; Lotton, Pierrick; Dalmont, Jean-Pierre

    2013-05-01

    The successful design of a thermoacoustic engine depends on the appropriate description of the processes involved inside the thermoacoustic core (TAC). This is a difficult task when considering the complexity of both the heat transfer phenomena and the geometry of the porous material wherein the thermoacoustic amplification process occurs. An attempt to getting round this difficulty consists in measuring the TAC transfer matrix under various heating conditions, the measured transfer matrices being exploited afterward into analytical models describing the complete apparatus. In this paper, a method based on impedance measurements is put forward, which allows the accurate measurement of the TAC transfer matrix, contrarily to the classical two-load method. Four different materials are tested, each one playing as the porous element allotted inside the TAC, which is submitted to different temperature gradients to promote thermoacoustic amplification. The experimental results are applied to the modeling of basic standing-wave and traveling-wave engines, allowing the prediction of the engine operating frequency and thermoacoustic amplification gain, as well as the optimum choice of the components surrounding the TAC. PMID:23654373

  7. Core design of long life-cycle fast reactors operating without reactivity margin

    SciTech Connect

    Aristova, E. N.; Baydin, D. F.; Gol'din, V. Y.; Pestryakova, G. A.; Stoynov, M. I. [Keldysh Inst. of Applied Mathematics RAS, Miusskaya sq., bld.4, 125047, Moscow (Russian Federation)

    2012-07-01

    In this paper we consider a possibility of designing a fast reactor core that operates without reactivity margin for a long time. This study is based on the physical principle of fast reactor operating in a self-adjustable neutron-nuclear regime (SANNR-1) introduced by L.P. Feoktistov (1988-1993) and improved by V. Ya. Gol'din SANNR-2 (1995). The mathematical modeling of active zones of fast reactors in SANNR modes is held by authors since 1992. The numerical simulation is based on solving the neutron transport equation coupled with quasi-diffusion equations. The calculations have been performed using standard 26 energy groups. We use a hierarchy of spatial models of 1D, 1.5D, 2D, and 3D geometries. The spatial models of higher dimensionality are used for verification of results. The calculations showed that operation of the reactor in this mode increases its efficiency, safety and simplifies management. It is possible to achieve continuous work of the reactor in SANNR-2 during 7-10 years without fuel overloads by means of further optimization of the mode. Small reactivity margin is used only for the reactor start up. After first 10-15 days the reactor in SANNR-2 operates without reactivity margin. (authors)

  8. Modular Approach to Launch Vehicle Design Based on a Common Core Element

    NASA Technical Reports Server (NTRS)

    Creech, Dennis M.; Threet, Grady E., Jr.; Philips, Alan D.; Waters, Eric D.; Baysinger, Mike

    2010-01-01

    With a heavy lift launch vehicle as the centerpiece of our nation's next exploration architecture's infrastructure, the Advanced Concepts Office at NASA's Marshall Space Flight Center initiated a study to examine the utilization of elements derived from a heavy lift launch vehicle for other potential launch vehicle applications. The premise of this study is to take a vehicle concept, which has been optimized for Lunar Exploration, and utilize the core stage with other existing or near existing stages and boosters to determine lift capabilities for alternative missions. This approach not only yields a vehicle matrix with a wide array of capabilities, but also produces an evolutionary pathway to a vehicle family based on a minimum development and production cost approach to a launch vehicle system architecture, instead of a purely performance driven approach. The upper stages and solid rocket booster selected for this study were chosen to reflect a cross-section of: modified existing assets in the form of a modified Delta IV upper stage and Castor-type boosters; potential near term launch vehicle component designs including an Ares I upper stage and 5-segment boosters; and longer lead vehicle components such as a Shuttle External Tank diameter upper stage. The results of this approach to a modular launch system are given in this paper.

  9. Design of hollow-core photonic bandgap fibers for CH4 and C2H2 optical fiber sensors

    Microsoft Academic Search

    Qiu-guo Wang; Bo-jun Yang

    2009-01-01

    A hollow-core photonic bandgap fiber for optical fiber sensors is designed. According to the calculation, we get the parameters of the photonic bandgap fiber as d=0.94*2.60?m, R=?=2.60?m for C2H2, and d=0.94*2.41?m, R=?=2.41?m for CH4. Around the wavelength of ?C2 H2 = 1.53?m and ?CH4 = 1.66?m, 98% of the energy is propagated in the core, the fiber is suitable to

  10. Strong volume reduction of common mode choke for RFI filters with the help of nanocrystalline cores design and experiments

    NASA Astrophysics Data System (ADS)

    Thierry, Waeckerlé; Thierry, Save; Benoît, Vachey; Dominique, Gautard

    2006-09-01

    The design of common mode chokes (CMC) for radio frequency interference filter is considered, explained and applied to the compared magnetic core characterization and computation between ferrite and nanocrystalline materials. The latter shows some better insertion losses at low frequencies when comparison is made with the same component characteristics. The volume of the component can be reduced by 50-80% when an appropriate ferrite is replaced by a well-chosen nanocrystalline core, as a result of its superimposed advantages of high and tailored permeabilitys, high saturation and inductive behavior near CMC resonance.

  11. The influence of various core designs on stress distribution in the veneered zirconia crown: a finite element analysis study

    PubMed Central

    Ha, Seung-Ryong; Kim, Sung-Hun; Yoo, Seung-Hyun; Jeong, Se-Chul; Lee, Jai-Bong; Yeo, In-Sung

    2013-01-01

    PURPOSE The purpose of this study was to evaluate various core designs on stress distribution within zirconia crowns. MATERIALS AND METHODS Three-dimensional finite element models, representing mandibular molars, comprising a prepared tooth, cement layer, zirconia core, and veneer porcelain were designed by computer software. The shoulder (1 mm in width) variations in core were incremental increases of 1 mm, 2 mm and 3 mm in proximal and lingual height, and buccal height respectively. To simulate masticatory force, loads of 280 N were applied from three directions (vertical, at a 45° angle, and horizontal). To simulate maximum bite force, a load of 700 N was applied vertically to the crowns. Maximum principal stress (MPS) was determined for each model, loading condition, and position. RESULTS In the maximum bite force simulation test, the MPSs on all crowns observed around the shoulder region and loading points. The compressive stresses were located in the shoulder region of the veneer-zirconia interface and at the occlusal region. In the test simulating masticatory force, the MPS was concentrated around the loading points, and the compressive stresses were located at the 3 mm height lingual shoulder region, when the load was applied horizontally. MPS increased in the shoulder region as the shoulder height increased. CONCLUSION This study suggested that reinforced shoulder play an essential role in the success of the zirconia restoration, and veneer fracture due to occlusal loading can be prevented by proper core design, such as shoulder. PMID:23755346

  12. Efficient transformer design by computing core loss using a novel approach

    Microsoft Academic Search

    A. Basak; Chi-Hang Yu; G. Lloyd

    1994-01-01

    Manufacturers and users of transformers are nowadays capitalising the core losses while considering the costings. Therefore a software package which enables an engineer to predict within a short period the approximate core loss in a transformer of any rating and geometry will be very useful. This paper describes how such a 2-D package has been developed using the finite element

  13. THE DEVELOPMENT OF MODERN DESIGN AND REFERENCE CORE NEUTRONICS METHODS FOR THE PBMR

    Microsoft Academic Search

    T D NEWTON

    The Pebble Bed Modular Reactor (PBMR) introduces several challenges for core neutronic methods. The particulate fuel is highly heterogeneous with a random distribution within the fuel pebbles and requires unique methods to calculate the effects of fuel resonance self shielding. In addition, the flow of fuel through the core is specific to the PBMR, again requiring specialised methods to model

  14. Conceptual Design of a Modular Island Core Fast Breeder Reactor “RAPID-M”

    Microsoft Academic Search

    Mitsuru KAMBE

    2002-01-01

    A metal fueled modular island core sodium cooled fast breeder reactor concept RAPID-M to improve reactor performance and proliferation resistance and to accommodate various power requirements has been demonstrated. The essential feature of the RAPID-M concept is that the reactor core consists of integrated fuel assemblies (IFAs) instead of conventional fuel subassemblies. The RAPID concept enables quick and simplified refueling

  15. Effective design of a sandwich beam with a metal foam core

    Microsoft Academic Search

    E. Magnucka-Blandzi; K. Magnucki

    2007-01-01

    The subject of the paper is a simply supported sandwich beam with a metal foam core. Mechanical properties of the core vary through its depth. A nonlinear hypothesis of deformation of a plane cross section of the beam is assumed and described. The elastic potential energy and the work of the load are formulated. The system of differential equations of

  16. Designing fast LTL model checking algorithms for many-core GPUs

    Microsoft Academic Search

    Ji?í Barnat; Petr Bauch; Luboš Brim; Milan ?eška

    Recent technological developments made various many-core hardware platforms widely accessible. These massively parallel architectures have been used to significantly accelerate many computation demanding tasks. In this paper, we show how the algorithms for LTL model checking can be redesigned in order to accelerate LTL model checking on many-core GPU platforms. Our detailed experimental evaluation demonstrates that using the NVIDIA CUDA

  17. Designing the core zone in a biosphere reserve based on suitable habitats: Yancheng Biosphere Reserve and the red crowned crane ( Grus japonensis)

    Microsoft Academic Search

    Wenjun Li; Zijian Wang; Zhijun Ma; Hongxiao Tang

    1999-01-01

    Although much research has been undertaken to design nature reserves, there are few practical methods to determine the interior structure of a reserve. A procedure for design of the core zone in reserves is proposed. As a case study, the core zone in Yancheng Biosphere Reserve, People's Republic of China, which was established to preserve the endangered red crowned crane

  18. Design and fabrication of hollow-core photonic crystal fibers for high-power ultrashort pulse transportation and pulse compression.

    PubMed

    Wang, Y Y; Peng, Xiang; Alharbi, M; Dutin, C Fourcade; Bradley, T D; Gérôme, F; Mielke, Michael; Booth, Timothy; Benabid, F

    2012-08-01

    We report on the recent design and fabrication of kagome-type hollow-core photonic crystal fibers for the purpose of high-power ultrashort pulse transportation. The fabricated seven-cell three-ring hypocycloid-shaped large core fiber exhibits an up-to-date lowest attenuation (among all kagome fibers) of 40 dB/km over a broadband transmission centered at 1500 nm. We show that the large core size, low attenuation, broadband transmission, single-mode guidance, and low dispersion make it an ideal host for high-power laser beam transportation. By filling the fiber with helium gas, a 74 ?J, 850 fs, and 40 kHz repetition rate ultrashort pulse at 1550 nm has been faithfully delivered at the fiber output with little propagation pulse distortion. Compression of a 105 ?J laser pulse from 850 fs down to 300 fs has been achieved by operating the fiber in ambient air. PMID:22859102

  19. System design specification for rotary mode core sample trucks No. 2, 3, and 4 programmable logic controller

    SciTech Connect

    Dowell, J.L.; Akers, J.C.

    1995-12-31

    The system this document describes controls several functions of the Core Sample Truck(s) used to obtain nuclear waste samples from various underground storage tanks at Hanford. The system will monitor the sampling process and provide alarms and other feedback to insure the sampling process is performed within the prescribed operating envelope. The intended audience for this document is anyone associated with rotary or push mode core sampling. This document describes the Alarm and Control logic installed on Rotary Mode Core Sample Trucks (RMCST) {number_sign}2, 3, and 4. It is intended to define the particular requirements of the RMCST alarm and control operation (not defined elsewhere) sufficiently for detailed design to implement on a Programmable Logic Controller (PLC).

  20. Thermal Hydraulics Design and Analysis Methodology for a Solid-Core Nuclear Thermal Rocket Engine Thrust Chamber

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Canabal, Francisco; Chen, Yen-Sen; Cheng, Gary; Ito, Yasushi

    2013-01-01

    Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions. This chapter describes a thermal hydraulics design and analysis methodology developed at the NASA Marshall Space Flight Center, in support of the nuclear thermal propulsion development effort. The objective of this campaign is to bridge the design methods in the Rover/NERVA era, with a modern computational fluid dynamics and heat transfer methodology, to predict thermal, fluid, and hydrogen environments of a hypothetical solid-core, nuclear thermal engine the Small Engine, designed in the 1960s. The computational methodology is based on an unstructured-grid, pressure-based, all speeds, chemically reacting, computational fluid dynamics and heat transfer platform, while formulations of flow and heat transfer through porous and solid media were implemented to describe those of hydrogen flow channels inside the solid24 core. Design analyses of a single flow element and the entire solid-core thrust chamber of the Small Engine were performed and the results are presented herein

  1. Verification of the CENTRM Module for Adaptation of the SCALE Code to NGNP Prismatic and PBR Core Designs

    SciTech Connect

    Ganapol, Barry; Maldonado, Ivan

    2014-01-23

    The generation of multigroup cross sections lies at the heart of the very high temperature reactor (VHTR) core design, whether the prismatic (block) or pebble-bed type. The design process, generally performed in three steps, is quite involved and its execution is crucial to proper reactor physics analyses. The primary purpose of this project is to develop the CENTRM cross-section processing module of the SCALE code package for application to prismatic or pebble-bed core designs. The team will include a detailed outline of the entire processing procedure for application of CENTRM in a final report complete with demonstration. In addition, they will conduct a thorough verification of the CENTRM code, which has yet to be performed. The tasks for this project are to: Thoroughly test the panel algorithm for neutron slowing down; Develop the panel algorithm for multi-materials; Establish a multigroup convergence 1D transport acceleration algorithm in the panel formalism; Verify CENTRM in 1D plane geometry; Create and test the corresponding transport/panel algorithm in spherical and cylindrical geometries; and, Apply the verified CENTRM code to current VHTR core design configurations for an infinite lattice, including assessing effectiveness of Dancoff corrections to simulate TRISO particle heterogeneity.

  2. High Temperature Reactor (HTR) Deep Burn Core and Fuel Analysis: Design Selection for the Prismatic Block Reactor

    SciTech Connect

    Francesco Venneri; Chang-Keun Jo; Jae-Man Noh; Yonghee Kim; Claudio Filippone; Jonghwa Chang; Chris Hamilton; Young-Min Kim; Ji-Su Jun; Moon-Sung Cho; Hong-Sik Lim; MIchael A. Pope; Abderrafi M. Ougouag; Vincent Descotes; Brian Boer

    2010-09-01

    The Deep Burn (DB) Project is a U.S. Department of Energy sponsored feasibility study of Transuranic Management using high burnup fuel in the high temperature helium cooled reactor (HTR). The DB Project consists of seven tasks: project management, core and fuel analysis, spent fuel management, fuel cycle integration, TRU fuel modeling, TRU fuel qualification, and HTR fuel recycle. In the Phase II of the Project, we conducted nuclear analysis of TRU destruction/utilization in the HTR prismatic block design (Task 2.1), deep burn fuel/TRISO microanalysis (Task 2.3), and synergy with fast reactors (Task 4.2). The Task 2.1 covers the core physics design, thermo-hydraulic CFD analysis, and the thermofluid and safety analysis (low pressure conduction cooling, LPCC) of the HTR prismatic block design. The Task 2.3 covers the analysis of the structural behavior of TRISO fuel containing TRU at very high burnup level, i.e. exceeding 50% of FIMA. The Task 4.2 includes the self-cleaning HTR based on recycle of HTR-generated TRU in the same HTR. Chapter IV contains the design and analysis results of the 600MWth DB-HTR core physics with the cycle length, the average discharged burnup, heavy metal and plutonium consumptions, radial and axial power distributions, temperature reactivity coefficients. Also, it contains the analysis results of the 450MWth DB-HTR core physics and the analysis of the decay heat of a TRU loaded DB-HTR core. The evaluation of the hot spot fuel temperature of the fuel block in the DB-HTR (Deep-Burn High Temperature Reactor) core under full operating power conditions are described in Chapter V. The investigated designs are the 600MWth and 460MWth DB-HTRs. In Chapter VI, the thermo-fluid and safety of the 600MWth DB-HTRs has been analyzed to investigate a thermal-fluid design performance at the steady state and a passive safety performance during an LPCC event. Chapter VII describes the analysis results of the TRISO fuel microanalysis of the 600MWth and 450MWth DB-HTRs. The TRISO fuel microanalysis covers the gas pressure buildup in a coated fuel particle including helium production, the thermo-mechanical behavior of a CFP, the failure probabilities of CFPs, the temperature distribution in a CPF, and the fission product (FP) transport in a CFP and a graphite. In Chapter VIII, it contains the core design and analysis of sodium cooled fast reactor (SFR) with deep burn HTR reactor. It considers a synergistic combination of the DB-MHR and an SFR burner for a safe and efficient transmutation of the TRUs from LWRs. Chapter IX describes the design and analysis results of the self-cleaning (or self-recycling) HTR core. The analysis is considered zero and 5-year cooling time of the spent LWR fuels.

  3. Hybrid wireless Network on Chip: a new paradigm in multi-core design

    Microsoft Academic Search

    Partha Pratim Pande; Amlan Ganguly; Kevin Chang; Christof Teuscher

    2009-01-01

    The performance benefits of conventional Network-on-Chip (NoC) architectures are limited by the high latency and energy dissipation in long distance multihop communication between embedded cores. This limitation of conventional NoC architectures can be addressed by introducing long-range, high bandwidth and low power wireless links between the distant cores. Using miniaturized on-chip antennas as an enabling technology, wireless NoCs (WiNoCs) can

  4. Design of a single-polarization single-mode photonic crystal fiber double-core coupler

    Microsoft Academic Search

    Jianfeng Li; Kailiang Duan; Yishan Wang; Xiangjie Cao; Yongkang Guo; Xiangdi Lin

    2009-01-01

    A simple single-polarization single-mode (SPSM) photonic crystal fiber (PCF) coupler with two cores is introduced. The full-vector finite-element method (FEM) is applied to analyze the modal interference phenomenon of the even and odd modes of two orthogonal polarizations and the power propagation within the two cores. Meanwhile, the SPSM coupling wavelength range and its corresponding coupling length for different structure

  5. Designing Scalable FPGA-Based Reduction Circuits Using Pipelined Floating-Point Cores

    Microsoft Academic Search

    Ling Zhuo; Gerald R. Morris; Viktor K. Prasanna

    2005-01-01

    The use of pipelined floating-point arithmetic cores to create high-performance FPGA-based computational ker- nels has introduced a new class of problems that do not exist when using single-cycle arithmetic cores. In par- ticular, the data hazards associated with pipelined floating-point reduction circuits can limit the scalabil- ity or severely reduce the performance of an otherwise high-performancecomputationalkernel. The inability to ef-

  6. Design of Gas-phase Synthesis of Core-Shell Particles by Computational Fluid – Aerosol Dynamics

    PubMed Central

    Buesser, B.; Pratsinis, S.E.

    2013-01-01

    Core-shell particles preserve the bulk properties (e.g. magnetic, optical) of the core while its surface is modified by a shell material. Continuous aerosol coating of core TiO2 nanoparticles with nanothin silicon dioxide shells by jet injection of hexamethyldisiloxane precursor vapor downstream of titania particle formation is elucidated by combining computational fluid and aerosol dynamics. The effect of inlet coating vapor concentration and mixing intensity on product shell thickness distribution is presented. Rapid mixing of the core aerosol with the shell precursor vapor facilitates efficient synthesis of hermetically coated core-shell nanoparticles. The predicted extent of hermetic coating shells is compared to the measured photocatalytic oxidation of isopropanol by such particles as hermetic SiO2 shells prevent the photocatalytic activity of titania. Finally the performance of a simpler, plug-flow coating model is assessed by comparisons to the present detailed CFD model in terms of coating efficiency and silica average shell thickness and texture. PMID:23729817

  7. Optimized design and predicted performance of a deep ocean 50 m piston coring system

    SciTech Connect

    Karnes, C. H.; Burchett, S. N.; Dzwilewski, P. T.

    1980-01-01

    Calculational techniques are described which were developed or adapted for the purpose of analyzing the mechanical response of a proposed piston coring system capable of recovering high quality 50 m long cores. The analysis includes the effects of barrel geometry on the mass required to penetrate 50 m of an assumed sediment, the effects of non-vertical entry and pullout on the stresses within the barrel, and the effects of steel cable or parachute piston restraints on the resulting core sample distortion. The results show that a wall thickness of 50 mm in the upper section is necessary to survive an entry of up to 1.5/sup 0/ from vertical or a recovery angle of up to 5/sup 0/. They also show that a mass of 15,400 kg and a pullout force of 330 kN are required. It is shown that active piston control is necessary to eliminate piston motion during penetration.

  8. Ten Core Principles for Designing Effective Learning Environments: Insights from Brain Research and Pedagogical Theory

    ERIC Educational Resources Information Center

    Boettcher, Judith V.

    2007-01-01

    In this article, Judith V. Boettcher provides ten core learning principles that can guide technology-enhanced teaching as well as more traditional forms of instruction. Drawn from both traditional pedagogical theory as well as current research about how people learn, the ten principles integrate these findings in a helpful set of guidelines that…

  9. A core-theoretic solution for the design of cooperative agreements on transfrontier pollution

    Microsoft Academic Search

    Parkash Chander; Henry Tulkens

    1995-01-01

    For a simple economic model of transfrontier pollution, widely used in theoretical studies of international treaties bearing on joint abatement, we offer in this paper a scheme for sharing national abatement costs through international financial transfers that is inspired by a classical solution concept from the theory of cooperative games—namely, the core of a game. The scheme has the following

  10. A Core-Theoretic Solution for the Design of Cooperative Agreements on Transfrontier Pollution

    Microsoft Academic Search

    Parkash Chander; Henry Tulkens

    1994-01-01

    For a simple economic model of transfrontier pollution, widely used in theoretical studies of international treaties bearing on joint abatement, we offer in this paper a scheme for sharing national abatement costs through international financial transfers that is inspired by a classical solution concept from the theory of cooperative games?namely, the core of a game. The scheme has the following

  11. Hardware-Assisted Reliability Enhancement for Embedded Multi-core Virtualization Design

    Microsoft Academic Search

    Tsung-Han Lin; Yuki Kinebuchi; Alexandre Courbot; Hiromasa Shimada; Takushi Morita; Hitoshi Mitake; Chen-Yi Lee; Tatsuo Nakajima

    2011-01-01

    In this paper, we propose a virtualization ar- chitecture for the multi-core embedded system to provide more system reliability and security while maintaining the same performance without introducing additional special hard- ware supports or having to implement complex protection mechanism in the virtualization layer. Virtualization has been widely used in embedded systems, especially in consumer electronics, albeit itself is not

  12. New multi-core Intel Xeon processors help design energy efficient solution for high performance computing

    Microsoft Academic Search

    Pawel Gepner; David L. Fraser; Michal Filip Kowalik; R. Tylman

    2009-01-01

    The second generation of Intel® Xeon¿ processors based on core microarchitecture and 45 nm process technology bring not only a new level of performance but also significant improvement in power characteristics. Continuous performance improvement and power efficiency are the paradigms for most data centers today and are also the challenges that will not go away anytime soon. The increasing energy

  13. Designing a VH-mode core/L-mode edge discharge

    SciTech Connect

    Staebler, G.M.; Hinton, F.L. [General Atomics, San Diego, CA (United States); Wiley, J.C. [Univ. of Texas, Austin, TX (United States). Fusion Research Center

    1995-12-01

    An operating mode with a very high confinement core like the VH-mode but a very low power flow to the divertor plates and low edge particle confinement like an L-mode would be beneficial. For a large tokamak like the proposed ITER, the power density at the separatrix is not that far above the scaled H-mode power threshold so not much of the power can be radiated inside of the separatrix without causing a return to L-mode. The thicker scrape-off layer of an L-mode increases the radiating volume of the scrape-off layer and helps shield impurities from the core. This is especially important if the first wall is metallic. In this paper an H-mode transport model based on E x B velocity shear suppression of turbulence will be used to show that it is possible to have a strongly radiating mantle near the separatrix, which keeps the edge in L-mode, while having a VH-mode core with a broad region of suppressed turbulence. The existing results of enhanced L-mode confinement during impurity injection on a number of tokamaks will be surveyed. The operating conditions which will most likely result in the further improvement of the core confinement by control of the heating, fueling, and torque profiles will be identified.

  14. Powder Cores s Molypermalloy

    E-print Network

    Software q Current Transformer Design Software q Inductor Design Software q Mag Amp Design Software POWDER.mag-inc.com PRODUCT LITERATURE AND DESIGN SOFTWARE CD CONTAINS q All Product Literature q Common Mode FIlter Design the Proper Core for Saturating Transformers q TWC-S3 Inverter Transformer Core Design and Material Selection

  15. Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol. 39, No. 11, p. 11691181 (November 2002) Conceptual Design of a Modular Island Core Fast Breeder Reactor "RAPID-M"

    E-print Network

    Laughlin, Robert B.

    Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol. 39, No. 11, p. 1169­1181 (November 2002) Conceptual Design of a Modular Island Core Fast Breeder Reactor "RAPID-M" Mitsuru KAMBE Central Research Institute and accepted September 10, 2002) A metal fueled modular island core sodium cooled fast breeder reactor concept

  16. An Empirical Determination of Tasks Essential to Successful Performance as a Floral Designer. Determination of a Common Core of Basic Skills in Agribusiness and Natural Resources.

    ERIC Educational Resources Information Center

    Miller, Daniel R.; And Others

    To improve vocational educational programs in agriculture, occupational information on a common core of basic skills within the occupational area of the floral designer is presented in the revised task inventory survey. The purpose of the occupational survey was to identify a common core of basic skills which are performed and are essential for…

  17. SCC500: next-generation infrared imaging camera core products with highly flexible architecture for unique camera designs

    NASA Astrophysics Data System (ADS)

    Rumbaugh, Roy N.; Grealish, Kevin; Kacir, Tom; Arsenault, Barry; Murphy, Robert H.; Miller, Scott

    2003-09-01

    A new 4th generation MicroIR architecture is introduced as the latest in the highly successful Standard Camera Core (SCC) series by BAE SYSTEMS to offer an infrared imaging engine with greatly reduced size, weight, power, and cost. The advanced SCC500 architecture provides great flexibility in configuration to include multiple resolutions, an industry standard Real Time Operating System (RTOS) for customer specific software application plug-ins, and a highly modular construction for unique physical and interface options. These microbolometer based camera cores offer outstanding and reliable performance over an extended operating temperature range to meet the demanding requirements of real-world environments. A highly integrated lens and shutter is included in the new SCC500 product enabling easy, drop-in camera designs for quick time-to-market product introductions.

  18. A Monte Carlo model system for core analysis and epithermal neutron beam design at the Washington State University Radiation Center

    SciTech Connect

    Burns, T.D. Jr.

    1996-05-01

    The Monte Carlo Model System (MCMS) for the Washington State University (WSU) Radiation Center provides a means through which core criticality and power distributions can be calculated, as well as providing a method for neutron and photon transport necessary for BNCT epithermal neutron beam design. The computational code used in this Model System is MCNP4A. The geometric capability of this Monte Carlo code allows the WSU system to be modeled very accurately. A working knowledge of the MCNP4A neutron transport code increases the flexibility of the Model System and is recommended, however, the eigenvalue/power density problems can be run with little direct knowledge of MCNP4A. Neutron and photon particle transport require more experience with the MCNP4A code. The Model System consists of two coupled subsystems; the Core Analysis and Source Plane Generator Model (CASP), and the BeamPort Shell Particle Transport Model (BSPT). The CASP Model incorporates the S({alpha}, {beta}) thermal treatment, and is run as a criticality problem yielding, the system eigenvalue (k{sub eff}), the core power distribution, and an implicit surface source for subsequent particle transport in the BSPT Model. The BSPT Model uses the source plane generated by a CASP run to transport particles through the thermal column beamport. The user can create filter arrangements in the beamport and then calculate characteristics necessary for assessing the BNCT potential of the given filter want. Examples of the characteristics to be calculated are: neutron fluxes, neutron currents, fast neutron KERMAs and gamma KERMAs. The MCMS is a useful tool for the WSU system. Those unfamiliar with the MCNP4A code can use the MCMS transparently for core analysis, while more experienced users will find the particle transport capabilities very powerful for BNCT filter design.

  19. Space Station Furnace Facility Core. Requirements definition and conceptual design study. Volume 2: Technical report. Appendix 6: Technical summary reports

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Space Station Furnace Facility (SSFF) is a modular facility for materials research in the microgravity environment of the Space Station Freedom (SSF). The SSFF is designed for crystal growth and solidification research in the fields of electronic and photonic materials, metals and alloys, and glasses and ceramics and will allow for experimental determination of the role of gravitational forces in the solidification process. The facility will provide a capability for basic scientific research and will evaluate the commercial viability of low-gravity processing of selected technologically important materials. The facility is designed to support a complement of furnace modules as outlined in the Science Capabilities Requirements Document (SCRD). The SSFF is a three rack facility that provides the functions, interfaces, and equipment necessary for the processing of the furnaces and consists of two main parts: the SSFF Core Rack and the two Experiment Racks. The facility is designed to accommodate two experimenter-provided furnace modules housed within the two experiment racks, and is designed to operate these two furnace modules simultaneously. The SCRD specifies a wide range of furnace requirements and serves as the basis for the SSFF conceptual design. SSFF will support automated processing during the man-tended operations and is also designed for crew interface during the permanently manned configuration. The facility is modular in design and facilitates changes as required, so the SSFF is adept to modifications, maintenance, reconfiguration, and technology evolution.

  20. IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 10, NO. 3, APRIL 2000 439 A Simple Processor Core Design for DCT/IDCT

    E-print Network

    Ha, Dong S.

    . This problem is not affective in this AU-based design due to the software-like controller design. Furthermore A Simple Processor Core Design for DCT/IDCT Tian-Sheuan Chang, Student Member, IEEE, Chin-Sheng Kung that features the simplest hardware and is suitable for discrete cosine transform/indiscrete cosine transform

  1. Vibration Characteristics Determined for Stainless Steel Sandwich Panels With a Metal Foam Core for Lightweight Fan Blade Design

    NASA Technical Reports Server (NTRS)

    Ghosn, Louis J.; Min, James B.; Raj, Sai V.; Lerch, Bradley A.; Holland, Frederic A., Jr.

    2004-01-01

    The goal of this project at the NASA Glenn Research Center is to provide fan materials that are safer, weigh less, and cost less than the currently used titanium alloy or polymer matrix composite fans. The proposed material system is a sandwich fan construction made up of thin solid face sheets and a lightweight metal foam core. The stiffness of the sandwich structure is increased by separating the two face sheets by the foam layer. The resulting structure has a high stiffness and lighter weight in comparison to the solid facesheet material alone. The face sheets carry the applied in-plane and bending loads (ref. 1). The metal foam core must resist the transverse shear and transverse normal loads, as well as keep the facings supported and working as a single unit. Metal foams have ranges of mechanical properties, such as light weight, impact resistance, and vibration suppression (ref. 2), which makes them more suitable for use in lightweight fan structures. Metal foams have been available for decades (refs. 3 and 4), but the difficulties in the original processes and high costs have prevented their widespread use. However, advances in production techniques and cost reduction have created a new interest in this class of materials (ref. 5). The material chosen for the face sheet and the metal foam for this study was the aerospace-grade stainless steel 17-4PH. This steel was chosen because of its attractive mechanical properties and the ease with which it can be made through the powder metallurgy process (ref. 6). The advantages of a metal foam core, in comparison to a typical honeycomb core, are material isotropy and the ease of forming complex geometries, such as fan blades. A section of a 17-4PH sandwich structure is shown in the following photograph. Part of process of designing any blade is to determine the natural frequencies of the particular blade shape. A designer needs to predict the resonance frequencies of a new blade design to properly identify a useful operating range. Operating a blade at or near the resonance frequencies leads to high-cycle fatigue, which ultimately limits the blade's durability and life. So the aim of this study is to determine the variation of the resonance frequencies for an idealized sandwich blade as a function of its face-sheet thickness, core thickness, and foam density. The finite element method is used to determine the natural frequencies for an idealized rectangular sandwich blade. The proven Lanczos method (ref. 7) is used in the study to extract the natural frequency.

  2. Thermal hydraulic method for whole core design analysis of an HTGR

    SciTech Connect

    Huning, A. J.; Garimella, S. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

    2013-07-01

    A new thermal hydraulic method and initial results are presented for core-wide steady state analysis of prismatic High Temperature Gas-Cooled Reactors (HTGR). The method allows for the complete solution of temperature and coolant mass flow distribution by solving quasi-steady energy balances for the discretized core. Assembly blocks are discretized into unit cells for which the average temperature of each unit cell is determined. Convective heat removal is coupled to the unit cell energy balances by a 1-D axial flow model. The flow model uses established correlations for friction factor and Nusselt number. Bypass flow is explicitly calculated by using an initial guess for mass flow distribution and determining the exit pressure of each flow channel. The mass flow distribution is updated until a uniform core exit pressure condition is reached. Results are obtained for the MHTGR-350 with emphasis on the change in thermal hydraulic parameters due to various steady state power profiles and bypass gap widths. Steady state temperature distribution and its variations are discussed. (authors)

  3. Design and synthesis of novel ROR inverse agonists with a dibenzosilole scaffold as a hydrophobic core structure.

    PubMed

    Toyama, Hirozumi; Nakamura, Masaharu; Hashimoto, Yuichi; Fujii, Shinya

    2015-07-01

    Molecular structure calculations indicated that the dibenzosilole skeleton could be well superposed on phenanthridinone, which is a structural component of ligands of retinoic acid receptor-related orphan receptors (RORs). Therefore, we designed, synthesized and biologically evaluated a series of novel ROR ligands based on the dibenzosilole scaffold as a hydrophobic core structure. Dibenzosilole derivatives bearing a hexafluoro-2-hydroxypropyl group on the benzene ring exhibited significant ROR-inhibitory activity, comparable to that of the lead phenanthridinone derivative 5. Our results indicate that the dibenzosilole skeleton would be a useful scaffold for developing novel biologically active compounds, and that cis-amide structure can be replaced by an alkylsilyl functionality. PMID:26014484

  4. GPU Based General-Purpose Parallel computing to Solve Nuclear Reactor In-Core fuel Management Design and Operation Problem

    SciTech Connect

    Prayudhatama, D.; Waris, A.; Kurniasih, N.; Kurniadi, R. [Bosscha Laboratory, Department of Physics, Nuclear Physics and Biophysics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung (Indonesia)

    2010-06-22

    In-core fuel management study is a crucial activity in nuclear power plant design and operation. Its common problem is to find an optimum arrangement of fuel assemblies inside the reactor core. Main objective for this activity is to reduce the cost of generating electricity, which can be done by altering several physical properties of the nuclear reactor without violating any of the constraints imposed by operational and safety considerations. This research try to address the problem of nuclear fuel arrangement problem, which is, leads to the multi-objective optimization problem. However, the calculation of the reactor core physical properties itself is a heavy computation, which became obstacle in solving the optimization problem by using genetic algorithm optimization.This research tends to address that problem by using the emerging General Purpose Computation on Graphics Processing Units (GPGPU) techniques implemented by C language for CUDA (Compute Unified Device Architecture) parallel programming. By using this parallel programming technique, we develop parallelized nuclear reactor fitness calculation, which is involving numerical finite difference computation. This paper describes current prototype of the parallel algorithm code we have developed on CUDA, that performs one hundreds finite difference calculation for nuclear reactor fitness evaluation in parallel by using GPU G9 Hardware Series developed by NVIDIA.

  5. Mixed-clock issue queue design for energy aware, high-performance cores

    Microsoft Academic Search

    Venkata Syam P. Rapaka; Emil Talpes; Diana Marculescu

    2004-01-01

    Globally-Asynchronous, Locally-Synchronous (GALS) design style has started to gain interest recently as a possible solution to the increased design complexity, power and thermal costs, as well as an enabler for allowing fine grain speed and voltage management. Due to its inherent complexity, a possible driver application for such a design style is the case of superscalar, out-of-order processors. This paper

  6. Very High Temperature Reactor (VHTR) Deep Burn Core and Fuel Analysis -- Complete Design Selection for the Pebble Bed Reactor

    SciTech Connect

    B. Boer; A. M. Ougouag

    2010-09-01

    The Deep-Burn (DB) concept focuses on the destruction of transuranic nuclides from used light water reactor fuel. These transuranic nuclides are incorporated into TRISO coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400). Although it has been shown in the previous Fiscal Year (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup, while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239-Pu, 240-Pu and 241-Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a ”standard,” UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge burnup level, while retaining its inherent safety characteristics. Using generic pebble bed reactor cores, this task will perform physics calculations to evaluate the capabilities of the pebble bed reactor to perform utilization and destruction of LWR used-fuel transuranics. The task will use established benchmarked models, and will introduce modeling advancements appropriate to the nature of the fuel considered (high TRU content and high burn-up).

  7. Hyperglycosylated Stable Core Immunogens Designed To Present the CD4 Binding Site Are Preferentially Recognized by Broadly Neutralizing Antibodies

    PubMed Central

    Ingale, Jidnyasa; Tran, Karen; Kong, Leopold; Dey, Barna; McKee, Krisha; Schief, William; Kwong, Peter D.; Mascola, John R.

    2014-01-01

    ABSTRACT The HIV-1 surface envelope glycoprotein (Env) trimer mediates entry into CD4+ CCR5+ host cells. Env possesses conserved antigenic determinants, such as the gp120 primary receptor CD4 binding site (CD4bs), a known neutralization target. Env also contains variable regions and protein surfaces occluded within the trimer that elicit nonneutralizing antibodies. Here we engineered additional N-linked glycans onto a cysteine-stabilized gp120 core (0G) deleted of its major variable regions to preferentially expose the conformationally fixed CD4bs. Three, 6, 7, and 10 new NXT/S glycan (G) motifs were engineered into 0G to encode 3G, 6G, 7G, and 10G cores. Following purification, most glycoproteins, except for 10G, were recognized by broadly neutralizing CD4bs-directed antibodies. Gel and glycan mass spectrometry confirmed that additional N-glycans were posttranslationally added to the redesigned cores. Binding kinetics revealed high-affinity recognition by seven broadly neutralizing CD4bs-directed antibodies and low to no binding by non-broadly neutralizing CD4bs-directed antibodies. Rabbits inoculated with the hyperglycosylated cores elicited IgM and IgG responses to each given protein that were similar in their neutralization characteristics to those elicited by parental 0G. Site-specific glycan masking effects were detected in the elicited sera, and the antisera competed with b12 for CD4bs-directed binding specificity. However, the core-elicited sera showed limited neutralization activity. Trimer priming or boosting of the core immunogens elicited tier 1-level neutralization that mapped to both the CD4bs and V3 and appeared to be trimer dependent. Fine mapping at the CD4bs indicated that conformational stabilization of the cores and addition of N-glycans altered the molecular surface of Env sites of vulnerability to neutralizing antibody, suggesting an explanation for why the elicited neutralization was not improved by this rational design strategy. IMPORTANCE Major obstacles to developing an effective HIV-1 vaccine include the variability of the envelope surface glycoproteins and its high-density glycan shield, generated by incorporation of host (human) glycosylation. HIV-1 does harbor highly conserved sites on the exposed envelope protein surface of gp120, one of which is the virus receptor (CD4) binding site. Several broadly neutralizing antibodies elicited from HIV patients do target this gp120 CD4 binding site (CD4bs); however, gp120 immunogens do not elicit broadly neutralizing antibodies. In this study, we targeted the CD4bs by conformational stabilization and additional glycan masking. We used the atomic-level structure to reengineer gp120 cores to preferentially present the cysteine-stabilized CD4bs and to mask (by glycan) nonneutralizing determinants. Importantly, glycan masking did successfully focus antibody responses to the CD4bs; however, the elicited CD4bs-directed antibodies did not neutralize HIV or bind to unmodified gp120, presumably due to the structure-guided modifications of the modified gp120 core. PMID:25253346

  8. HW\\/SW coverification performance estimation and benchmark for a 24 embedded RISC core design

    Microsoft Academic Search

    Thomas W. Albrecht; Johann Notbauer; Stefan Rohringer

    1998-01-01

    This paper describes the benchmarking of a HW\\/SW-coverification design strategy. The benchmark results were the base for making a principal verification decision for an already ongoing project at Siemens AG, Public Communication Network Group. The intention for this benchmark was to verify whether commercial available coverification tools can handle the design complexity of an embedded system containing 24 embedded RISC

  9. High power density nanocrystalline core transformer design for resonant converter systems

    Microsoft Academic Search

    W. Shen; F. Wang; D. Boroyevich; C. W. Tipton

    2005-01-01

    Design issues of high power density transformers for resonant converter systems are discussed. Under the specified operating condition, the transformer is designed to achieve the minimum volume. Finemet® nanocrystalline magnetic material is suitable for the pulse applications, due to its superior low loss density and high operating temperature characteristics. 1000 W\\/in3 power density is achieved for the 30 kW pulse

  10. RosettaHoles: Rapid assessment of protein core packing for structure prediction, refinement, design, and validation

    PubMed Central

    Sheffler, Will; Baker, David

    2009-01-01

    We present a novel method called RosettaHoles for visual and quantitative assessment of underpacking in the protein core. RosettaHoles generates a set of spherical cavity balls that fill the empty volume between atoms in the protein interior. For visualization, the cavity balls are aggregated into contiguous overlapping clusters and small cavities are discarded, leaving an uncluttered representation of the unfilled regions of space in a structure. For quantitative analysis, the cavity ball data are used to estimate the probability of observing a given cavity in a high-resolution crystal structure. RosettaHoles provides excellent discrimination between real and computationally generated structures, is predictive of incorrect regions in models, identifies problematic structures in the Protein Data Bank, and promises to be a useful validation tool for newly solved experimental structures. PMID:19177366

  11. Genomic Design of Strong Direct-Gap Optical Transition in Si/Ge Core/Multishell Nanowires

    SciTech Connect

    Zhang, L.; d'Avezac, M.; Luo, J. W.; Zunger, A.

    2012-02-08

    Finding a Si-based material with strong optical activity at the band-edge remains a challenge despite decades of research. The interest lies in combining optical and electronic functions on the same wafer, while retaining the extraordinary know-how developed for Si. However, Si is an indirect-gap material. The conservation of crystal momentum mandates that optical activity at the band-edge includes a phonon, on top of an electron-hole pair, and hence photon absorption and emission remain fairly unlikely events requiring optically rather thick samples. A promising avenue to convert Si-based materials to a strong light-absorber/emitter is to combine the effects on the band-structure of both nanostructuring and alloying. The number of possible configurations, however, shows a combinatorial explosion. Furthermore, whereas it is possible to readily identify the configurations that are formally direct in the momentum space (due to band-folding) yet do not have a dipole-allowed transition at threshold, the problem becomes not just calculation of band structure but also calculation of absorption strength. Using a combination of a genetic algorithm and a semiempirical pseudopotential Hamiltonian for describing the electronic structures, we have explored hundreds of thousands of possible coaxial core/multishell Si/Ge nanowires with the orientation of [001], [110], and [111], discovering some 'magic sequences' of core followed by specific Si/Ge multishells, which can offer both a direct bandgap and a strong oscillator strength. The search has revealed a few simple design principles: (i) the Ge core is superior to the Si core in producing strong bandgap transition; (ii) [001] and [110] orientations have direct bandgap, whereas the [111] orientation does not; (iii) multishell nanowires can allow for greater optical activity by as much as an order of magnitude over plain nanowires; (iv) the main motif of the winning configurations giving direct allowed transitions involves rather thin Si shell embedded within wide Ge shells. We discuss the physical origin of the enhanced optical activity, as well as the effect of possible experimental structural imperfections on optical activity in our candidate core/multishell nanowires.

  12. Conceptual Design and Feasibility of Foil Bearings for Rotorcraft Engines: Hot Core Bearings

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.

    2007-01-01

    Recent developments in gas foil bearing technology have led to numerous advanced high-speed rotating system concepts, many of which have become either commercial products or experimental test articles. Examples include oil-free microturbines, motors, generators and turbochargers. The driving forces for integrating gas foil bearings into these high-speed systems are the benefits promised by removing the oil lubrication system. Elimination of the oil system leads to reduced emissions, increased reliability, and decreased maintenance costs. Another benefit is reduced power plant weight. For rotorcraft applications, this would be a major advantage, as every pound removed from the propulsion system results in a payload benefit.. Implementing foil gas bearings throughout a rotorcraft gas turbine engine is an important long-term goal that requires overcoming numerous technological hurdles. Adequate thrust bearing load capacity and potentially large gearbox applied radial loads are among them. However, by replacing the turbine end, or hot section, rolling element bearing with a gas foil bearing many of the above benefits can be realized. To this end, engine manufacturers are beginning to explore the possibilities of hot section gas foil bearings in propulsion engines. This overview presents a logical follow-on activity by analyzing a conceptual rotorcraft engine to determine the feasibility of a foil bearing supported core. Using a combination of rotordynamic analyses and a load capacity model, it is shown to be reasonable to consider a gas foil bearing core section. In addition, system level foil bearing testing capabilities at NASA Glenn Research Center are presented along with analysis work being conducted under NRA Cooperative Agreements.

  13. Novel design of honeycombs using a seamless combination of auxetic and conventional cores toward phononic band gap engineering

    NASA Astrophysics Data System (ADS)

    Mukherjee, Sushovan; Scarpa, Fabrizio; Gopalakrishnan, S.

    2015-04-01

    A novel design for the geometric configuration of honeycombs using a seamless combination of auxetic and conventional cores-elements with negative and positive Possion ratios respectively, has been presented. The proposed design has been shown to generate a superior band gap property while retaining all major advantages of a purely conventional or purely auxetic honeycomb structure. Seamless combination ensures that joint cardinality is also retained. Several configurations involving different degree of auxeticity and different proportions auxetic and conventional elements have been analyzed. It has been shown that the preferred configurations open up wide and clean band gap at a significantly lower frequency ranges compared to their pure counterparts. In view of existence of band gaps being desired feature for the phononic applications, reported results might be appealing. Use of such design may enable superior vibration control as well. Proposed configurations can be made isovolumic and iso-weight giving designers a fairer ground of applying such configurations without significantly changing size and weight criteria.

  14. Design of the Core Stage Inter-Tank Umbilical {CSITU) Compliance Mechanism

    NASA Technical Reports Server (NTRS)

    Smith, Kurt R.

    2013-01-01

    Project Goals: a) Design the compliance mechanism for the CSITU system to a 30% level -3D models completed in Pro/Engineer -Relevant design analysis b) Must meet all system requirements and establish basis for proceeding with detailed design. Tasks to be completed: A design that meets requirements for the 30% design review, 01/16/2013. Umbilical arms provide commodities to the launch vehicle prior to T-0. Commodities can range anywhere from hydraulics, pneumatics, cryogenic, electrical, ECS, etc ... Umbilicals commonly employ truss structures to deliver commodities to vehicle. Common configurations include: -Tilt-up -Swing Arm -Hose Drape -Drop Arm Umbilical arms will be mounted to Mobile Launch Platform. SLS currently has 9 T-0 umbilical arms. The compliance refers to the ability of the umbilical to adjust to minor changes in vehicle location. The compliance mechanism refers to the mechanism on the ground support equipment {GSE) that compensates for these changes. For the CSITU, these minor changes, or vehicle excursions, can be up to +4 in. Excursions refer to movements of the vehicle caused by wind loads and thermal expansion. It is ideal to have significant vertical compliance so a passive secondary release mechanism may be implemented.

  15. Conceptual design for an air core 2 meg-amp reversed field experiment

    SciTech Connect

    Hammer, C.F.

    1983-01-01

    The Los Alamos CTR Division is involved in the conceptual design of a next phase Reversed Field Pinch experiment. The paper will discuss, in general, some of the physics questions that the experiment will address. Also in more detail it will discuss the engineering parameters and the possible hardware design solutions. The experiment is designed to produce a plasma current of about 2 MA which can be sustained for about 200 ms. The electrical energy for the system is provided by a large motor generator set. An inductive energy store is used to drive the magnetizing and poloidal field windings. A capacitor bank provides the energy for the toroidal field windings. The current in both circuits is maintained by using SCR controlled transformer rectifiers.

  16. Mutual inductance of air-cored coils: Effect on design of radio-frequency coupled implants

    Microsoft Academic Search

    F. C. Flack; E. D. James; D. M. Schlapp

    1971-01-01

    Values of mutual inductance between two circular conductors lying in parallel planes have been computed. The results are presented\\u000a in graphical form and their relevance to the design of radio-frequency coupled implant systems is mentioned.

  17. Physics implications of oxide and metal fuel on the design of small LMFBR cores

    Microsoft Academic Search

    Y. Orechwa; H. Khalil

    1984-01-01

    In order to maintain momentum in the US LMFBR program, much attention has recently been focused on the possibility of new design approaches consistent with the slower deployment scenarios currently envisioned. To this end, the slower rate of deployment of LMFBR capacity lends itself to a scenario wherein small capacity reactors are constructed as demand requires, in a reactor complex

  18. Application of computer visualization to core reactor physics analysis and design

    Microsoft Academic Search

    Z. Zhu; D. J. Kropaczek; P. J. Turinsky

    1993-01-01

    Advances in graphical user interface (GUI) technology have been accompanied by increasingly sophisticated software applications. This is particularly evident in the area of nuclear fuel management, where the almost complete automation of the reload design process should be realized in the near future. Beyond simple automation, however, the exploitation of visualization capabilities permitted with current technology will allow the reload

  19. Design of a Radiation Tolerant Computing System Based on a Many-Core FPGA Architecture

    E-print Network

    LaMeres, Brock J.

    when the particles create soft errors such as inadvertent logic level switching that is captured). The system design implements 64 PicoBlaze soft processors to provide spare circuitry in the event of a hard are induced using a push button switch while hardware failures are created using a graphical user interface

  20. Core design and reactor physics of a breed and burn gas-cooled fast reactor

    E-print Network

    Yarsky, Peter

    2005-01-01

    In order to fulfill the goals set forth by the Generation IV International Forum, the current NERI funded research has focused on the design of a Gas-cooled Fast Reactor (GFR) operating in a Breed and Burnm (B&B) fuel cycle ...

  1. Optimal shape design of iron core to reduce cogging torque of IPM motor

    Microsoft Academic Search

    Dong-Hun Kim; Il-Han Park; Joon-Ho Lee; Chang-Eob Kim

    2003-01-01

    This paper presents a practical design method to dramatically reduce cogging torque of an interior permanent-magnet (IPM) motor without deteriorating other performances. Using the continuum sensitivity analysis combined with the finite-element method (FEM), the optimal shape of a rotor is investigated. The Lagrange sliding interface technique and an objective function expressed in terms of stored system energy allow fast convergence

  2. The design and installation of a core discharge monitor for CANDU-type reactors

    SciTech Connect

    Halbig, J.K. (Los Alamos National Lab., NM (USA)); Monticone, A.C.; Ksiezak, L. (International Atomic Energy Agency, Vienna (Austria)); Smiltnieks, V. (International Atomic Energy Agency, Toronto, ON (Canada). Regional Office)

    1990-01-01

    A new type of surveillance systems that monitors neutron and gamma radiation in a reactor containment is being installed at the Ontario Hydro Darlington Nuclear Generating Station A, Unit 2. Unlike video or film surveillance that monitors mechanical motion, this system measures fuel-specific radiation emanating from irradiated fuel as it is pushed from the core of CANDU-type reactors. Proof-of-principle measurements have been carried out at Bruce Nuclear Generating Station A, Unit 3. The system uses ({gamma},n) threshold detectors and ionization detectors. A microprocessor-based electronics package, GRAND-II (Gamma Ray and Neutron Detector electronics package), provides detector bias, preamplifier power, and signal processing. Firmware in the GRAND-2 controls the surveillance activities, including data acquisition and a level of detector authentication, and it handles authenticated communication with a central data logging computer. Data from the GRAND-II are transferred to an MS-DOS-compatible computer and stored. These data are collected and reviewed for fuel-specific radiation signatures from the primary detector and proper ratios of signals from secondary detectors. 5 figs.

  3. A survey of alternative once-through fast reactor core designs

    SciTech Connect

    Fei, T.; Richard, J. G.; Kersting, A. R.; Don, S. M.; Oi, C.; Driscoll, M. J.; Shwageraus, E. [Nuclear Science and Engineering Dept., Massachusetts Inst. of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2012-07-01

    Reprocessing of Light Water Reactor (LWR) spent fuel to recover plutonium or transuranics for use in Sodium cooled Fast Reactors (SFRs) is a distant prospect in the U.S.A. This has motivated our evaluation of potentially cost-effective operation of uranium startup fast reactors (USFRs) in a once-through mode. This review goes beyond findings reported earlier based on a UC fueled MgO reflected SFR to describe a broader parametric study of options. Cores were evaluated for a variety of fuel/coolant/reflector combinations: UC/UZr/UO{sub 2}/UN;Na/Pb; MgO/SS/Zr. The challenge is achieving high burnup while minimizing enrichment and respecting both cladding fluence/dpa and reactivity lifetime limits. These parametric studies show that while UC fuel is still the leading contender, UO{sub 2} fuel and ZrH 1.7 moderated metallic fuel are also attractive if UC proves to be otherwise inadequate. Overall, these findings support the conclusion that a competitive fuel cycle cost and uranium utilization compared to LWRs is possible for SFRs operated on a once-through uranium fueled fuel cycle. In addition, eventual transition to TRU recycle mode is studied, as is a small test reactor to demonstrate key features. (authors)

  4. Design and optimization of a multi-cores photonic crystal fiber for spatial flat in-phase supermode laser output

    NASA Astrophysics Data System (ADS)

    Zhou, Cheng; Zhang, Hai-Kun; Song, Peng; Wang, Jing; Li, Xin

    2015-01-01

    We report a new recipe, which is combinatorially optimizing distribution of Yb3+-doped concentration and geometrical structure of the multi-cores photonic crystal fiber (MCPCF) to obtain the equal amplitude distribution of the in-phase supermode. We present theoretical model based on the perturbation theory of coupled modes and vector finite element method (VFEM). Furthermore, a 7-cores PCF is designed. The equal amplitude distribution can be obtained through only optimizing distribution of Yb3+-doped concentration or geometrical structure, which is studied in detail. The results show that the doped concentration-ratio tolerance is 4% for only optimizing doped concentration and the air-hole diameter ratio tolerance is 0.74% for only optimizing geometrical structure. For simultaneously optimizing them, both the doped concentration-ratio tolerance and the air-hole diameter ratio tolerance are 7.6%, which is larger than 4% and 0.74%. So, in order to obtain spatially flat in-phase supermode, we simultaneously adjust the doped concentration ratio and the air-hole diameter ratio, which will facilely implement in experimental operation.

  5. New Designs of a Two-Phase E-Core Switched Reluctance Machine by Optimizing the Magnetic Structure for a Specific Application: Concept, Design, and Analysis

    Microsoft Academic Search

    Cheewoo Lee; R. Krishnan

    2008-01-01

    Three new magnetic structures for an E-core SRM comprising two segmented stator cores or a monolithic stator core are proposed for good manufacturability, mechanically robustness, ease of assembly, and electromagnetic performance improvement. The E-core stator has four small poles with phase windings and two or four large poles (hereafter referred to as common poles), in between. The common poles do

  6. Design of 9.271-pressure-ratio 5-stage core compressor and overall performance for first 3 stages

    NASA Technical Reports Server (NTRS)

    Steinke, Ronald J.

    1986-01-01

    Overall aerodynamic design information is given for all five stages of an axial flow core compressor (74A) having a 9.271 pressure ratio and 29.710 kg/sec flow. For the inlet stage group (first three stages), detailed blade element design information and experimental overall performance are given. At rotor 1 inlet tip speed was 430.291 m/sec, and hub to tip radius ratio was 0.488. A low number of blades per row was achieved by the use of low-aspect-ratio blading of moderate solidity. The high reaction stages have about equal energy addition. Radial energy varied to give constant total pressure at the rotor exit. The blade element profile and shock losses and the incidence and deviation angles were based on relevant experimental data. Blade shapes are mostly double circular arc. Analysis by a three-dimensional Euler code verified the experimentally measured high flow at design speed and IGV-stator setting angles. An optimization code gave an optimal IGV-stator reset schedule for higher measured efficiency at all speeds.

  7. Integration of the FORMOSA PWR in-core fuel management optimization code into nuclear design code systems

    SciTech Connect

    Sawyer, J.M.; Murphy, P.R.; Parks, G.T.; Maldonado, G.I.; Turinsky, P.J. (North Carolina State Univ., Raleigh (United States)); Daniels, D.A. (Carolina Power and Light Co., Raleigh, NC (United States))

    1991-01-01

    North Carolina State University has, in collaboration with Duke Power and Carolina Power and Light Company (CP and L), developed an in-core fuel management code, FORMOSA, which automatically provides the much needed computational capability to determine optimal pressurized water reactor loading patterns (LPs) for a variety of objective functions. FORMOSA employs simulated annealing to control the optimization process, using the exchange of fuel assemblies between randomly selected locations to seek improvements in the LP. Candidate patterns are assessed using second-order generalized perturbation theory (GPT) expressions for the characteristics of interest based on a two-dimensional, coarse-mesh finite difference discretization of the two-group neutron diffusion equations. Before its potential can be exploited, FORMOSA must be integrated into a utility's nuclear design system. This task was undertaken at both Duke Power and CP and L, which employ the Studsvik and Scandpower methodologies, respectively.

  8. OECD MCCI project long-term 2-D molten core concrete interaction test design report, Rev. 0. September 30, 2002.

    SciTech Connect

    Farmer, M. T.; Kilsdonk, D. J.; Lomperski, S.; Aeschliman, R. W.; Basu, S. (Nuclear Engineering Division); (NRC)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following two technical objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of the first program objective, the Small-Scale Water Ingression and Crust Strength (SSWICS) test series has been initiated to provide fundamental information on the ability of water to ingress into cracks and fissures that form in the debris during quench, thereby augmenting the otherwise conduction-limited heat transfer process. A test plan for Melt Eruption Separate Effects Tests (MESET) has also been developed to provide information on the extent of crust growth and melt eruptions as a function of gas sparging rate under well-controlled experiment conditions. In terms of the second program objective, the project Management Board (MB) has approved startup activities required to carry out experiments to address remaining uncertainties related to long-term two-dimensional molten core-concrete interaction. In particular, for both wet and dry cavity conditions, there is uncertainty insofar as evaluating the lateral vs. axial power split during a core-concrete interaction due to a lack of experiment data. As a result, there are differences in the 2-D cavity erosion predicted by codes such as MELCOR, WECHSL, and COSACO. The first step towards generating this data is to produce a test plan for review by the Project Review Group (PRG). The purpose of this document is to provide this plan.

  9. College of Design Core Waiver Form Complete this form if extenuating circumstances prevent the completion of all Core requirements prior to the submission of

    E-print Network

    Mayfield, John

    ALL PROGRAMS FOR WHICH YOU ARE REQUESTING A WAIVER ARCHITECTURE GRAPHIC DESIGN INTERIOR DESIGN must be met in order to enroll in the program. Architecture Chair Signature Date: Graphic Design, the following conditions must be met in order to enroll in the program. Graphic Design Chair Signature Date: 2

  10. ITER Core Imaging X-Ray Spectrometer Conceptual Design and Performance Assessment - Phase 2

    SciTech Connect

    Beiersdorfer, P; Wen, J; Dunn, J; Morris, K

    2011-01-02

    During Phase 2 of our study of the CIXS conceptual design we have tackled additional important issues that are unique to the ITER environment. These include the thermal control of the crystal and detector enclosures located in an environment with a 100-250 C ambient temperature, tritium containment, and the range of crystal and detector movement based on the need for spectral adjustments and the desire to make measurements of colder plasmas. In addressing these issues we have selected a ''Dewar''-type enclosure for the crystals and detectors. Applying realistic view factors for radiant heat and making allowance for conduction we have made engineering studies of this enclosure and showed that the cooling requirements can be solved and the temperature can be kept sufficiently constant without compromising the specification parameters of the CIXS. We have chosen a minimum 3 mm combined thickness of the six beryllium windows needed in a Dewar-type enclosure and showed that a single window of 0.5 mm thickness satisfies tritium containment requirements. For measuring the temperature in cooler ITER plasmas, we have chosen to use the K-shell lines of Fe24+. Iron is the preferred choice because its radiation can be analyzed with the identical CIXS settings used for analyzing the tungsten radiation, i.e., essentially no adjustments besides a simple crystal rotation need to be made. We have, however, included an xy{theta}-drive motor arrangement in our design for fine adjustments and full rotation of the crystal mounts.

  11. Optical designs of reflection and refraction collection optics for a JT-60SA core Thomson scattering system

    NASA Astrophysics Data System (ADS)

    Tojo, H.; Hatae, T.; Hamano, T.; Sakuma, T.; Itami, K.

    2013-09-01

    Collection optics for core measurements in a JT-60SA Thomson scattering system were designed. The collection optics will be installed in a limited space and have a wide field of view and wide wavelength range. Two types of the optics are therefore suggested: refraction and reflection types. The reflection system, with a large primary mirror, avoids large chromatic aberrations. Because the size limit of the primary mirror and vignetting due to the secondary mirror affect the total collection throughput, conditions that provide the high throughput are found through an optimization. A refraction system with four lenses forming an Ernostar system is also employed. The use of high-refractive-index glass materials enhances the freedom of the lens curvatures, resulting in suppression of the spherical and coma aberration. Moreover, sufficient throughput can be achieved, even with smaller lenses than that of a previous design given in [H. Tojo, T. Hatae, T. Sakuma, T. Hamano, K. Itami, Y. Aida, S. Suitoh, and D. Fujie, Rev. Sci. Instrum. 81, 10D539 (2010)]. The optical resolutions of the reflection and refraction systems are both sufficient for understanding the spatial structures in plasma. In particular, the spot sizes at the image of the optics are evaluated as {˜}0.3 mm and {˜}0.4 mm, respectively. The throughput for the two systems, including the pupil size and transmissivity, are also compared. The results show that good measurement accuracy (<10%) even at high electron temperatures ({<}30 keV) can be expected in the refraction system.

  12. Optical designs of reflection and refraction collection optics for a JT-60SA core Thomson scattering system

    SciTech Connect

    Tojo, H.; Hatae, T.; Hamano, T.; Sakuma, T.; Itami, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193 (Japan)] [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193 (Japan)

    2013-09-15

    Collection optics for core measurements in a JT-60SA Thomson scattering system were designed. The collection optics will be installed in a limited space and have a wide field of view and wide wavelength range. Two types of the optics are therefore suggested: refraction and reflection types. The reflection system, with a large primary mirror, avoids large chromatic aberrations. Because the size limit of the primary mirror and vignetting due to the secondary mirror affect the total collection throughput, conditions that provide the high throughput are found through an optimization. A refraction system with four lenses forming an Ernostar system is also employed. The use of high-refractive-index glass materials enhances the freedom of the lens curvatures, resulting in suppression of the spherical and coma aberration. Moreover, sufficient throughput can be achieved, even with smaller lenses than that of a previous design given in [H. Tojo, T. Hatae, T. Sakuma, T. Hamano, K. Itami, Y. Aida, S. Suitoh, and D. Fujie, Rev. Sci. Instrum. 81, 10D539 (2010)]. The optical resolutions of the reflection and refraction systems are both sufficient for understanding the spatial structures in plasma. In particular, the spot sizes at the image of the optics are evaluated as ?0.3?mm and ?0.4?mm, respectively. The throughput for the two systems, including the pupil size and transmissivity, are also compared. The results show that good measurement accuracy (<10%) even at high electron temperatures (<30?keV) can be expected in the refraction system.

  13. New Designs of a Two-Phase E-Core Switched Reluctance Machine by Optimizing the Magnetic Structure for a Specific Application: Concept, Design, and Analysis

    Microsoft Academic Search

    Cheewoo Lee; Ramu Krishnan

    2009-01-01

    Three new magnetic structures for an E-core switched reluctance machine (SRM) comprising two segmented stator cores or a monolithic stator core are proposed for good manufacturability, mechanically robustness, ease of assembly, and electromagnetic-performance improvement. The E-core stator has four small poles with phase windings and two or four large poles (hereinafter referred to as common poles) in between. The common

  14. Neutronics methods, models, and applications at the Idaho National Engineering Laboratory for the advanced neutron source reactor three-element core design

    Microsoft Academic Search

    C. A. Wemple; B. G. Schnitzler; J. M. Ryskamp

    1995-01-01

    A summary of the methods and models used to perform neutronics analyses on the Advanced Neutron Source reactor three-element core design is presented. The applications of the neutral particle Monte Carlo code MCNP are detailed, as well as the expansion of the static role of MCNP to analysis of fuel cycle depletion calculations. Results to date of these applications are

  15. Quiet Clean Short-haul Experimental Engine (QCSEE) Under-The-Wing (UTW) boiler plate nacelle and core exhaust nozzle design report

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The mechanical design of the boiler plate nacelle and core exhaust nozzle for the QCSEE under the wing engine is presented. The nacelle, which features interchangeable hard-wall and acoustic panels, is to be utilized in the initial engine testing to establish acoustic requirements for the subsequent composite nacelle as well as in the QCSEE over the wing engine configuration.

  16. The Effectiveness of Professional Development Using a Checklist of Common Core State Standards for Mathematical Practice for Designing and Delivering Instruction on Algebra I Achievement

    ERIC Educational Resources Information Center

    Peretin, Janeen

    2014-01-01

    This study was designed to determine whether or not the use of focused professional development using a checklist based on the Common Core State Standards Mathematical Practices impacted students' math scores as measured by an assessment that requires the use of the practices. Additionally, the researcher sought to determine whether or not the use…

  17. From rational design of organometallic precursors to optimized synthesis of core/shell Ge/GeO2 nanoparticles.

    PubMed

    Matioszek, D; Ojo, W-S; Cornejo, A; Katir, N; El Ezzi, M; Le Troedec, M; Martinez, H; Gornitzka, H; Castel, A; Nayral, C; Delpech, F

    2015-04-01

    The synthesis of germanium nanoparticles has been carried out, thanks to the design of novel aminoiminate germanium(ii) precursors: (ATI)GeZ (with Z = OMe, NPh2, and ATI = N,N'-diisopropyl-aminotroponiminate) and (Am)2Ge (Am = N,N'-bis(trimethylsilyl)phenyl amidinate). These complexes were fully characterized by spectroscopic techniques as well as single crystal X-ray diffraction. The thermolysis of both complexes yielded NPs which display similar features that are a Ge/GeO2 core/shell structure with a mean diameter close to 5 nm with a narrow size distribution (<15%). Whereas the high temperatures (>300 °C) classically reported in the literature for the preparation of germanium-based NPs were necessary for thermolysis of the complexes (ATI)GeZ, the use of amidinate-based precursors allows the preparation at an unprecedented low temperature (160 °C) for the thermolytic route. As suggested by a mechanistic study, the lower reactivity of (ATI)GeZ (for which the concomitant use of high temperature and acidic reagent is required) was explained in terms of lower ring strain compared to the case of (Am)2Ge. PMID:25790067

  18. Core sample extractor

    NASA Technical Reports Server (NTRS)

    Akins, James; Cobb, Billy; Hart, Steve; Leaptrotte, Jeff; Milhollin, James; Pernik, Mark

    1989-01-01

    The problem of retrieving and storing core samples from a hole drilled on the lunar surface is addressed. The total depth of the hole in question is 50 meters with a maximum diameter of 100 millimeters. The core sample itself has a diameter of 60 millimeters and will be two meters in length. It is therefore necessary to retrieve and store 25 core samples per hole. The design utilizes a control system that will stop the mechanism at a certain depth, a cam-linkage system that will fracture the core, and a storage system that will save and catalogue the cores to be extracted. The Rod Changer and Storage Design Group will provide the necessary tooling to get into the hole as well as to the core. The mechanical design for the cam-linkage system as well as the conceptual design of the storage device are described.

  19. An automated system for core loss measurement and characterization: a useful tool for high frequency magnetic components design

    Microsoft Academic Search

    Adalberto J. Batista; J. C. S. Fagundes; Philippe Viarouge

    1998-01-01

    This paper describes an automated measurement system for core loss characterization in high frequency magnetic components. This system can accomplish these aims, within specified magnetic induction and frequency ranges, and at different temperatures, with high accuracy, due to the techniques used in the acquisition and computation of the waveforms involved in loss calculation. The core loss characterization, obtained by fitting

  20. Understanding origin of loss in large pitch hollow-core photonic crystal fibers and their design simplification.

    PubMed

    Février, Sébastien; Beaudou, Benoît; Viale, Pierre

    2010-03-01

    It is now commonly accepted that, in large pitch hollow-core 'kagomé' lattice fibers, the loss spectrum is related to resonances of the thin silica webs in the photonic crystal cladding. Moreover, coherent scattering from successive holes' layers cannot be obtained and adding holes' layers does not decrease the loss level. In this communication, cross-comparison of experimental data and accurate numerical modeling is presented that helps demonstrate that waveguiding in large pitch hollow-core fibers arises from the antiresonance of the core surround only and does not originate from the photonic crystal cladding. The glass webs only mechanically support the core surround and are sources of extra leakage. Large pitch hollow-core fibers exhibit features of thin walled and thick walled tubular waveguides, the first one tailoring the transmission spectrum while the second one is responsible for the increased loss figure. As a consequence, an approximate calculus, based on specific features of both types of waveguides, gives the loss spectrum, in very good agreement with experimental data. Finally, a minimalist hollow-core microstructured fiber, the cladding of which consists of six thin bridges suspending the core surround, is proposed for the first time. PMID:20389527

  1. High Temperature Reactor (HTR) Deep Burn Core and Fuel Analysis: Design Selection for the Prismatic Block Reactor With Results from FY-2011 Activities

    SciTech Connect

    Michael A. Pope

    2011-10-01

    The Deep Burn (DB) Project is a U.S. Department of Energy sponsored feasibility study of Transuranic Management using high burnup fuel in the high temperature helium cooled reactor (HTR). The DB Project consists of seven tasks: project management, core and fuel analysis, spent fuel management, fuel cycle integration, TRU fuel modeling, TRU fuel qualification, and HTR fuel recycle. In the Phase II of the Project, we conducted nuclear analysis of TRU destruction/utilization in the HTR prismatic block design (Task 2.1), deep burn fuel/TRISO microanalysis (Task 2.3), and synergy with fast reactors (Task 4.2). The Task 2.1 covers the core physics design, thermo-hydraulic CFD analysis, and the thermofluid and safety analysis (low pressure conduction cooling, LPCC) of the HTR prismatic block design. The Task 2.3 covers the analysis of the structural behavior of TRISO fuel containing TRU at very high burnup level, i.e. exceeding 50% of FIMA. The Task 4.2 includes the self-cleaning HTR based on recycle of HTR-generated TRU in the same HTR. Chapter IV contains the design and analysis results of the 600MWth DB-HTR core physics with the cycle length, the average discharged burnup, heavy metal and plutonium consumptions, radial and axial power distributions, temperature reactivity coefficients. Also, it contains the analysis results of the 450MWth DB-HTR core physics and the analysis of the decay heat of a TRU loaded DB-HTR core. The evaluation of the hot spot fuel temperature of the fuel block in the DB-HTR (Deep-Burn High Temperature Reactor) core under full operating power conditions are described in Chapter V. The investigated designs are the 600MWth and 460MWth DB-HTRs. In Chapter VI, the thermo-fluid and safety of the 600MWth DB-HTRs has been analyzed to investigate a thermal-fluid design performance at the steady state and a passive safety performance during an LPCC event. Chapter VII describes the analysis results of the TRISO fuel microanalysis of the 600MWth and 450MWth DB-HTRs. The TRISO fuel microanalysis covers the gas pressure buildup in a coated fuel particle including helium production, the thermo-mechanical behavior of a CFP, the failure probabilities of CFPs, the temperature distribution in a CPF, and the fission product (FP) transport in a CFP and a graphite. In Chapter VIII, it contains the core design and analysis of sodium cooled fast reactor (SFR) with deep burn HTR reactor. It considers a synergistic combination of the DB-MHR and an SFR burner for a safe and efficient transmutation of the TRUs from LWRs. Chapter IX describes the design and analysis results of the self-cleaning (or self-recycling) HTR core. The analysis is considered zero and 5-year cooling time of the spent LWR fuels.

  2. Design of an overmoderated fuel and a full MOX core for plutonium consumption in boiling water reactors

    Microsoft Academic Search

    Juan Luis François; Cecilia Mart??n del Campo; Joel Hernández

    2002-01-01

    The use of uranium–plutonium mixed oxide fuel (MOX) in light water reactors (LWR) is nowadays a current practice in several countries. Generally 1\\/3 of the reactor core is loaded with MOX fuel assemblies and the other 2\\/3 with uranium assemblies. Nevertheless the plutonium utilization could be more effective if the full core could be loaded with MOX fuel. In this

  3. PowerDepot: Integrating IP-based power modeling with ESL power analysis for multi-core SoC designs

    Microsoft Academic Search

    Chen-Wei Hsu; Jia-Lu Liao; Shan-Chien Fang; Chia-Chien Weng; Shi-Yu Huang; Wen-Tsan Hsieh; Jen-Chieh Yeh

    2011-01-01

    paper, we introduce an integrated power methodology for multi-core SoC designs. It features not only a bottom-up IP-based power modeling for all kinds of IP components ranging from hardware accelerators, processors, and memory blocks, but also a top-down system-wide ESL power estimation formulation. By linking these two methods of different levels of abstraction, one can thereby easily profile the power

  4. Ultra-low power and high speed design and implementation of AES and SHA1 hardware cores in 65 nanometer CMOS technology

    Microsoft Academic Search

    Feng Ge; Pranjal Jain; Ken Choi

    2009-01-01

    This paper describes a design and implementation of low-power and high-speed security hardware cores for the advanced encryption standard (AES) and the secure hash algorithm (SHA1). We propose three register transfer level (RTL) circuit techniques, namely, application specific register reduction (ASRR), locally explicit clock enabling (LECE), and bus specific clock (BSC). LECE and BSC can be used directly to any

  5. Nuclear safety analyses and core design calculations to convert the Texas A & M University Nuclear Science Center reactor to low enrichment uranium fuel. Final report

    SciTech Connect

    Parish, T.A.

    1995-03-02

    This project involved performing the nuclear design and safety analyses needed to modify the license issued by the Nuclear Regulatory Commission to allow operation of the Texas A& M University Nuclear Science Center Reactor (NSCR) with a core containing low enrichment uranium (LEU) fuel. The specific type of LEU fuel to be considered was the TRIGA 20-20 fuel produced by General Atomic. Computer codes for the neutronic analyses were provided by Argonne National Laboratory (ANL) and the assistance of William Woodruff of ANL in helping the NSCR staff to learn the proper use of the codes is gratefully acknowledged. The codes applied in the LEU analyses were WIMSd4/m, DIF3D, NCTRIGA and PARET. These codes allowed full three dimensional, temperature and burnup dependent calculations modelling the NSCR core to be performed for the first time. In addition, temperature coefficients of reactivity and pulsing calculations were carried out in-house, whereas in the past this modelling had been performed at General Atomic. In order to benchmark the newly acquired codes, modelling of the current NSCR core with highly enriched uranium fuel was also carried out. Calculated results were compared to both earlier licensing calculations and experimental data and the new methods were found to achieve excellent agreement with both. Therefore, even if an LEU core is never loaded at the NSCR, this project has resulted in a significant improvement in the nuclear safety analysis capabilities established and maintained at the NSCR.

  6. The design and implementation of the IEEE 802.11 MAC based on soft-core processor and RTOS

    Microsoft Academic Search

    Wan’ang Xiao; Zhi Fang; Yin Shi

    2007-01-01

    The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)\\/\\u000a ARM (Advanced Reduced instruction set computer Machine) processor or DSP\\/ARM IP (Intellectual Property) core. This paper presents\\u000a a method based on Nios II soft-core processor embedded in Altera’s Cyclone FPGA (Field Programmable Gate Array) and MicroC\\/OS-II\\u000a RTOS (Real-Time Operation System).

  7. HYDRATE CORE DRILLING TESTS

    SciTech Connect

    John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

    2002-11-01

    The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate formation comprised of coarse, large-grain sand in ice. Results with this core showed that the viscosity of the drilling fluid must also be carefully controlled. When coarse sand was being cored, the core barrel became stuck because the drilling fluid was not viscous enough to completely remove the large grains of sand. These tests were very valuable to the project by showing the difficulties in coring permafrost or hydrates in a laboratory environment (as opposed to a field environment where drilling costs are much higher and the potential loss of equipment greater). Among the conclusions reached from these simulated hydrate coring tests are the following: Frozen hydrate core samples can be recovered successfully; A spring-finger core catcher works best for catching hydrate cores; Drilling fluid can erode the core and reduces its diameter, making it more difficult to capture the core; Mud must be designed with proper viscosity to lift larger cuttings; and The bottom 6 inches of core may need to be drilled dry to capture the core successfully.

  8. OECD MCCI project long-term 2-D molten core concrete interaction test design report, Rev. 0. September 30, 2002

    Microsoft Academic Search

    M. T. Farmer; D. J. Kilsdonk; S. Lomperski; R. W. Aeschliman; S. Basu

    2011-01-01

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool,

  9. The BS degree in Earth and Space Exploration, Concentration in Exploration Systems Design requires the following core courses

    E-print Network

    Rhoads, James

    the following core courses: SES 100 Introduction to Exploration (3) SES 101 Earth, Solar System, and Universe I (3) SES 102 Earth, Solar System, and Universe II (3) SES 103 Earth, Solar System, and Universe Laboratory I (1) SES 104 Earth, Solar System, and Universe Laboratory II (1) SES 210 Engineering Systems (3

  10. True crystalline fibers: double-clad LMA design concept of Tm:YAG-core fiber and its mode simulation

    NASA Astrophysics Data System (ADS)

    Mu, Xiaodong; Meissner, Helmuth; Lee, Huai-Chuan; Dubinskii, Mark

    2012-02-01

    We propose a sub-100 ?m double-clad single-crystalline Tm:YAG square core adhesive-free bond (AFB) waveguide structure as a prototype gain medium for an LMA ~2-?m fiber laser with ~790-nm diode laser pumping and present its mode simulation. The structure uses an undoped YAG and ceramic spinel for the inner and outer claddings, respectively. The mode simulation indicates that such double-clad structure can have over 1000-?m2 mode area in a 2% Tm:YAG core which will maintain a single transverse mode laser operation. The structure also has a large numerical aperture (~ 0.22) for the un-doped YAG inner cladding available for pumping.

  11. Improved hollow-core photonic crystal fiber design for delivery of nanosecond pulses in laser micromachining applications.

    PubMed

    Shephard, Jonathan D; Couny, Francois; Russell, Phillip St J; Jones, Julian D C; Knight, Jonathan C; Hand, Duncan P

    2005-07-20

    We report the delivery of high-energy nanosecond pulses (approximately 65 ns pulse width) from a high-repetition-rate (up to 100 kHz) Q-switched Nd:YAG laser through the fundamental mode of a hollow-core photonic crystal fiber (HC-PCF) at 1064 nm. The guided mode in the HC-PCF has a low overlap with the glass, allowing delivery of pulses with energies above those attainable with other fibers. Energies greater than 0.5 mJ were delivered in a single spatial mode through the hollow-core fiber, providing the pulse energy and high beam quality required for micromachining of metals. Practical micromachining of a metal sheet by fiber delivery has been demonstrated. PMID:16047910

  12. Improved hollow-core photonic crystal fiber design for delivery of nanosecond pulses in laser micromachining applications

    Microsoft Academic Search

    Jonathan D. Shephard; Francois Couny; Phillip St. J. Russell; Julian D. C. Jones; Jonathan C. Knight; Duncan P. Hand

    2005-01-01

    We report the delivery of high-energy nanosecond pulses (~65 ns pulse width) from a high-repetition-rate (up to 100 kHz) Q-switched Nd:YAG laser through the fundamental mode of a hollow-core photonic crystal fiber (HC-PCF) at 1064 nm. The guided mode in the HC-PCF has a low overlap with the glass, allowing delivery of pulses with energies above those attainable with other

  13. Neutronics methods, models, and applications at the Idaho National Engineering Laboratory for the advanced neutron source reactor three-element core design

    SciTech Connect

    Wemple, C.A.; Schnitzler, B.G.; Ryskamp, J.M. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-08-01

    A summary of the methods and models used to perform neutronics analyses on the Advanced Neutron Source reactor three-element core design is presented. The applications of the neutral particle Monte Carlo code MCNP are detailed, as well as the expansion of the static role of MCNP to analysis of fuel cycle depletion calculations. Results to date of these applications are presented also. A summary of the calculations not yet performed is also given to provide a {open_quotes}to-do{close_quotes} list if the project is resurrected.

  14. Design of hollow-core photonic band-gap fibers for CH4 and C2H2 optical fiber sensors

    Microsoft Academic Search

    Wang Qiu-guo; Zhang Jin-long; Zhang Lei; Chen Li-jia; Gao Wei

    2011-01-01

    A hollow-core photonic band-gap fiber for optical fiber sensors is designed. According to the calculation, we get the parameters of the photonic band-gap fiber as d=O.94*2.60J.lm, R=A=2.60J.lm for C2H2, and d=O.94*2.41J.lm, R=A=2.41J.lm for CH 4• Around the wavelength of A C 2H 2 == 1.53Jim and A CH 4 == 1.66Jim , 98% of the energy is propagated in the

  15. The ?PP ASIC: design, methodologies and tools for a pay phone system-on-a-chip based on an ARM core and design reuse

    Microsoft Academic Search

    Jacobo Riesco; Juan C. Díaz; Pierre I. Plaza

    1999-01-01

    This paper describes the ?PP (Microcontroller for Pay Phones) ASIC, a system-on-a-chip solution based on the present Spanish pay phone system. The design integrates an ARM embedded microprocessor, several third party blocks and new custom modules developed in house, using ARM's Advanced Microprocessors Bus Architecture (AMBA). The system has been designed for low power consumption and management. Design reuse, aided

  16. 758 IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS, VOL. 23, NO. 5, MAY 2004 Efficient Test Solutions for Core-Based Designs

    E-print Network

    Larsson, Erik

    with the Computer Design and Test Laboratory, Nara Institute of Science and Technology, Nara 630-0101, Japan (e is with the Computer Design and Test Laboratory, Nara Institute of Science and Technology, Nara 630-0101, Japan (e-mail: fujiwara@is.aist- nara.ac.jp). Digital Object Identifier 10.1109/TCAD.2004.826560 · how to design

  17. Testing Embedded Cores Using Partial Isolation Rings

    Microsoft Academic Search

    Nur A. Touba; Bahram Pouya

    1997-01-01

    Intellectual property cores pose a signifcant test challenge. The core supplier may not give any information about the internal logic of the core, but simply provide a set of test vectors for the core which guarantees a particular fault coverage. If the core is embedded within a larger design, then the problem is how to apply the specified test vectors

  18. Core Communication Interface for FPGAs

    Microsoft Academic Search

    José Carlos Palma; Aline Vieira De Mello; Leandro Möller; Ney Calazans

    2002-01-01

    The use of pre-designed and pre-verified hardware modules, also called IP cores, is an important part of the effort to design and implement complex systems. However, many aspects of IP core manipulation are still to be developed. This paper presents an approach to solveproblems related to the dynamic interconnection of hard IP cores. The approach targets system-on-a-chip designs build in

  19. Thermal-fluid assessment of the design options for reactor vessel cooling in a prismatic core VHTR

    Microsoft Academic Search

    Min-Hwan Kim; Nam-il Tak; Hong-Sik Lim

    2010-01-01

    The design of the reactor pressure vessel is an important issue in the VHTR design due to its high operating temperature. The extensive experience base in Light Water Reactor makes SA508\\/533 steel emerge as a strong candidate for the VHTR reactor vessel but requires maintaining the vessel temperature below the ASME code limit. To meet the temperature requirement, three types

  20. A design of IEEE 1451.2 compliant smart sensor based on the Nios soft-core processor

    Microsoft Academic Search

    Huiyao Cheng; Huabiao Qin

    2005-01-01

    Since 70s of last century, Internet technology has been greatly developed, and embedded Internet is a current trend in modern measurement and control systems. An IEEE 1451.2 compliant smart sensor based on embedded Internet technology is designed, prototyped and experimentally tested in the paper. This smart sensor designed has a compliant smart transducer interface module (STIM) and network capable application

  1. Nutrient Composition of the Peanut Core of the Core Collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanuts from the Core Collection designated as the Core of the Core Collection were grown in Tifton, GA in 2005. Amino acids, folic acid and total oil content were determined on the whole seed. Amino acid concentrations were generally close to commonly reported values. Folic acid concentration var...

  2. Design of a low enrichment, enhanced fast flux core for the Massachusetts Institute of Technology Research Reactor

    E-print Network

    Ellis, Tyler Shawn

    2009-01-01

    Worldwide, there is limited test reactor capacity to perform the required irradiation experiments on advanced fast reactor materials and fuel designs. This is particularly true in the U.S., which no longer has an operating ...

  3. Design Study for a Low-Enriched Uranium Core for the High Flux Isotope Reactor, Annual report for FY 2009

    SciTech Connect

    Chandler, David [ORNL; Freels, James D [ORNL; Ilas, Germina [ORNL; Miller, James Henry [ORNL; Primm, Trent [ORNL; Sease, John D [ORNL; Guida, Tracey [University of Pittsburgh; Jolly, Brian C [ORNL

    2010-02-01

    This report documents progress made during FY 2009 in studies of converting the High Flux Isotope Reactor (HFIR) from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. Conversion from HEU to LEU will require a change in fuel form from uranium oxide to a uranium-molybdenum alloy. With axial and radial grading of the fuel foil and an increase in reactor power to 100 MW, calculations indicate that the HFIR can be operated with LEU fuel with no degradation in reactor performance from the current level. Results of selected benchmark studies imply that calculations of LEU performance are accurate. Studies are reported of the application of a silicon coating to surrogates for spheres of uranium-molybdenum alloy. A discussion of difficulties with preparing a fuel specification for the uranium-molybdenum alloy is provided. A description of the progress in developing a finite element thermal hydraulics model of the LEU core is provided.

  4. An Overview of Demise Calculations, Conceptual Design Studies, and Hydrazine Compatibility Testing for the GPM Core Spacecraft Propellant Tank

    NASA Technical Reports Server (NTRS)

    Estes, Robert H.; Moore, N. R.

    2007-01-01

    NASA's Global Precipitation Measurement (GPM) mission is an ongoing Goddard Space Flight Center (GSFC) project whose basic objective is to improve global precipitation measurements. It has been decided that the GPM spacecraft is to be a "design for demise" spacecraft. This requirement resulted in the need for a propellant tank that would also demise or ablate to an appropriate degree upon re-entry. This paper will describe GSFC-performed spacecraft and tankage demise analyses, vendor conceptual design studies, and vendor performed hydrazine compatibility and wettability tests performed on 6061 and 2219 aluminum alloys.

  5. Analysis and design of photonic crystal fibers : Solid and hollow core fibers through the finite element method

    Microsoft Academic Search

    S. Selleri; A. Cucinotta

    2008-01-01

    Purpose – The aim of this paper is to show the effectiveness of the finite element method (FEM) to study the properties of different kinds of photonic crystal fibers (PCFs), presenting results which highlight the FEM flexibility, exploited according to the particular PCF feature under investigation. Design\\/methodology\\/approach – The FEM has been applied to a new emerging class of optical

  6. Identification of a critical motif for the human immunodeficiency virus type 1 (HIV-1) gp41 core structure: implications for designing novel anti-HIV fusion inhibitors.

    PubMed

    He, Yuxian; Cheng, Jianwei; Li, Jingjing; Qi, Zhi; Lu, Hong; Dong, Mingxin; Jiang, Shibo; Dai, Qiuyun

    2008-07-01

    Human immunodeficiency virus type 1 (HIV-1) entry into the host cell involves a cascade of events and currently represents one of most attractive targets in the search for new antiviral drugs. The fusion-active gp41 core structure is a stable six-helix bundle (6-HB) folded by its trimeric N-terminal heptad repeat (NHR) and C-terminal heptad repeat (CHR). Peptides derived from the CHR region of HIV-1 gp41 are potent fusion inhibitors that target the NHR to block viral and cellular membrane fusion in a dominant negative fashion. However, all CHR peptides reported to date are derived primarily from residues 628 to 673 of gp41; little attention has been paid to the upstream sequence of the pocket binding domain (PBD) in the CHR. Here, we have identified a motif ((621)QIWNNMT(627)) located at the upstream region of the gp41 CHR, immediately adjacent to the PBD ((628)WMEWEREI(635)). Biophysical characterization demonstrated that this motif is critical for the stabilization of the gp41 6-HB core. The peptide CP621-652, containing the (621)QIWNNMT(627) motif, was able to interact with T21, a counterpart peptide derived from the NHR, to form a typical 6-HB structure with a high thermostability (thermal unfolding transition [T(m)] value of 82 degrees C). In contrast, the 6-HB formed by the peptides N36 and C34, which has been considered to be a core structure of the fusion-active gp41, had a T(m) of 64 degrees C. Different from T-20 (brand name Fuseon), which is the first and only HIV-1 fusion inhibitor approved for clinical use, CP621-652 could efficiently block 6-HB formation in a dose-dependent manner. Significantly, CP621-652 had potent inhibitory activity against HIV-1-mediated cell-cell fusion and infection, especially against T-20- and C34-resistant virus. Therefore, our works provide important information for understanding the core structure of the fusion-active gp41 and for designing novel anti-HIV peptides. PMID:18417584

  7. Promoting student-led science and technology projects in elementary teacher education: entry into core pedagogical practices through technological design

    Microsoft Academic Search

    John Lawrence Bencze

    2010-01-01

    Future elementary school teachers often lack self-efficacy for teaching science and technology. They are particularly anxious\\u000a about encouraging children to carry-out student-directed, open-ended scientific inquiry and\\/or technological design projects.\\u000a Moreover, because this often also is the case with practising elementary school teachers, it is difficult for student–teachers\\u000a to gain practical experience facilitating student-led project work during practicum sessions. To provide

  8. DESIGN STUDY FOR A LOW-ENRICHED URANIUM CORE FOR THE HIGH FLUX ISOTOPE REACTOR, ANNUAL REPORT FOR FY 2010

    SciTech Connect

    Cook, David Howard [ORNL; Freels, James D [ORNL; Ilas, Germina [ORNL; Jolly, Brian C [ORNL; Miller, James Henry [ORNL; Primm, Trent [ORNL; Renfro, David G [ORNL; Sease, John D [ORNL; Pinkston, Daniel [ORNL

    2011-02-01

    This report documents progress made during FY 2010 in studies of converting the High Flux Isotope Reactor (HFIR) from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. Conversion from HEU to LEU will require a change in fuel form from uranium oxide to a uranium-molybdenum alloy. With axial and radial grading of the fuel foil and an increase in reactor power to 100 MW, calculations indicate that the HFIR can be operated with LEU fuel with no degradation in performance to users from the current level. Studies are reported of support to a thermal hydraulic test loop design, the implementation of finite element, thermal hydraulic analysis capability, and infrastructure tasks at HFIR to upgrade the facility for operation at 100 MW. A discussion of difficulties with preparing a fuel specification for the uranium-molybdenum alloy is provided. Continuing development in the definition of the fuel fabrication process is described.

  9. Design of a self-excited, air-core compulsator for a skid-mounted repetitive fire 9 MJ railgun system

    NASA Astrophysics Data System (ADS)

    Walls, W. A.; Spann, M. L.; Pratap, S. B.; Bresie, D.; Brinkman, Wm.

    1989-01-01

    The design of a lightweight, compulsator-driven 9-MJ electromagnetic (EM) launcher has been completed and is presently in the fabrication phase. Scheduled for initial field testing in early 1989, the system will be capable of firing a salvo of nine rounds in three minutes at muzzle velocities between 2.5 and 4.0 km/s. Prime power for the compulsator is supplied by a 5000-hp gas turbine engine through a gearbox and clutch arrangement, and auxiliary power is provided by a small 750-hp turbine. Electrical power generation and pulse conditioning for the launcher are performed by the compulsator, which features a self-excited, air-core magnetic circuit and selectively passive armature compensation designed to minimize peak projectile acceleration. Peak power from the machine is 27 GW, and a total of 30 MJ is extracted from the rotor during each firing of the gun. System mass, including gun, compulsator, prime power, and auxiliary systems, is less than 22 tons and will be mounted on a 36-ton concrete slab which simulates the mass of an armored vehicle on which the system will eventually be integrated.

  10. Design of single-winding energy-storage reactors for dc-to-dc converters using air-gapped magnetic-core structures

    NASA Technical Reports Server (NTRS)

    Ohri, A. K.; Wilson, T. G.; Owen, H. A., Jr.

    1977-01-01

    A procedure is presented for designing air-gapped energy-storage reactors for nine different dc-to-dc converters resulting from combinations of three single-winding power stages for voltage stepup, current stepup and voltage stepup/current stepup and three controllers with control laws that impose constant-frequency, constant transistor on-time and constant transistor off-time operation. The analysis, based on the energy-transfer requirement of the reactor, leads to a simple relationship for the required minimum volume of the air gap. Determination of this minimum air gap volume then permits the selection of either an air gap or a cross-sectional core area. Having picked one parameter, the minimum value of the other immediately leads to selection of the physical magnetic structure. Other analytically derived equations are used to obtain values for the required turns, the inductance, and the maximum rms winding current. The design procedure is applicable to a wide range of magnetic material characteristics and physical configurations for the air-gapped magnetic structure.

  11. Simple approximations of the DC flux influence on the core loss power electronic ferrites and their use in design of magnetic components

    Microsoft Academic Search

    Wai Keung Mo; David K. W. Cheng; Y. S. Lee

    1997-01-01

    The effect of DC flux on the core loss is examined for the practical range of power and frequency. Relevant core loss equations are derived and applied to an optimization algorithm to determine the minimum core loss at a given ratio of s (DC flux density to AC peak flux density). It has been found that the curves of hysteresis

  12. Superconducting tin core fiber

    NASA Astrophysics Data System (ADS)

    Homa, Daniel; Liang, Yongxuan; Hill, Cary; Kaur, Gurbinder; Pickrell, Gary

    2015-01-01

    In this study, we demonstrated superconductivity in a fiber with a tin core and fused silica cladding. The fibers were fabricated via a modified melt-draw technique and maintained core diameters ranging from 50-300 microns and overall diameters of 125-800 microns. Superconductivity of this fiber design was validated via the traditional four-probe test method in a bath of liquid helium at temperatures on the order of 3.8 K. The synthesis route and fiber design are perquisites to ongoing research dedicated all-fiber optoelectronics and the relationships between superconductivity and the material structures, as well as corresponding fabrication techniques.

  13. Quality by design approach for the separation of naproxcinod and its related substances by fused core particle technology column.

    PubMed

    Inugala, Ugandar Reddy; Pothuraju, Nageswara Rao; Vangala, Ranga Reddy

    2013-01-01

    This paper describes the development of a rapid, novel, stability-indicating gradient reversed-phase high-performance liquid chromatographic method and associated system suitability parameters for the analysis of naproxcinod in the presence of its related substances and degradents using a quality-by-design approach. All of the factors that affect the separation of naproxcinod and its impurities and their mutual interactions were investigated and robustness of the method was ensured. The method was developed using an Ascentis Express C8 150 × 4.6 mm, 2.7 µm column with a mobile phase containing a gradient mixture of two solvents. The eluted compounds were monitored at 230 nm, the run time was 20 min within which naproxcinod and its eight impurities were satisfactorily separated. Naproxcinod was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Naproxcinod was found to degrade significantly in acidic and basic conditions and to be stable in thermal, photolytic, oxidative and aqueous degradation conditions. The degradation products were satisfactorily resolved from the primary peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. PMID:23060406

  14. Design, synthesis and evaluation of novel triazole core based P-glycoprotein-mediated multidrug resistance reversal agents.

    PubMed

    Jiao, Lei; Qiu, Qianqian; Liu, Baomin; Zhao, Tianxiao; Huang, Wenlong; Qian, Hai

    2014-12-15

    A novel series of triazol-N-ethyl-tetrahydroisoquinoline based compounds were designed and synthesized via click chemistry. Most of the synthesized compounds showed P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) reversal activities. Among them, compound 7 with little cytotoxicity towards GES-1 cells (IC50 >80?M) and K562/A02 cells (IC50 >80?M) exhibited more potency than verapamil (VRP) on increasing anticancer drug accumulation in K562/A02 cells. Moreover, compound 7 could significantly reverse MDR in a dose-dependent manner and also persist longer chemo-sensitizing effect than VRP with reversibility. Further mechanism studies revealed that compound 7 in reversing MDR revealed that it could remarkably increase the intracellular accumulation of both rhodamine-123 (Rh123) and adriamycin (ADM) in K562/A02 cells as well as inhibit their efflux from the cells. These results suggested that compound 7 showed more potency than the classical P-gp inhibitor VRP under the same conditions, which may be a promising P-gp-mediated MDR modulator for further development. PMID:25464884

  15. Core restoration for crown preparation.

    PubMed

    Larson, Thomas D

    2004-01-01

    This article will review the relevant literature fom 1991-2003, a period of time when adhesive resin luting materials became available and luting crowns with zinc phosphate cements decreased. The review wtill look at the principles suggesting when a core should be placed, what core materials function best, preparation design with a core, luting material choice with a core, and results of clinical trials. Amalgam cores are regarded as the strongest material, best able to withstand adverse stress and restore teeth having the greatest loss of tooth structure. Composite resins, whether chemically cured or light cured, reinforced or not, appear best capable of core restorationfor moderately broken down teeth. Glass ionomer materials are considered too weak to withstand stress as a core material, but are recommended as a base material tofill in undercuts and improve the accuracy of impression and fit of a crown. PMID:15554446

  16. (w13) Institutional Core Management

    PubMed Central

    Turpen, P.; Farber, G.K.; Mische, S.; Alexander, P.; Auger, J.; Meyn, S.

    2011-01-01

    This workshop session will focus on issues related to Institutional Core Management, in response to the national conversation evolving around research core facility issues and management. The workshop will be formatted as an experts' panel; each participant currently plays an important role in supporting and developing research core resources at an institutional level. Some of the topics to be discussed include: (1) Core Consolidation — one size fits all? (2) Bottom-up vs. top-down management, advantages and disadvantages of centrally managed cores. (3) Performance metrics and impacts on professional development, core infrastructure support and improved operations. (4) Impacts of NIH-NCRR programs on improving access to research resources, including core facilities. We also plan to highlight the new Core Administrators Network Coordinating (CAN). In response to an emerging trend to centralize the oversight of research core facilities, ABRF has fostered development of this network and a new committee: the Core Administrators Network-Coordinating Committee (CAN-CC). The committee seeks input and participation from scientists, administrators and others with an interest in issues related to the administration of research core facilities which, by the nature of their service role, must interface with multiple constituencies within a research enterprise. Today many institutions have established administrative positions designed to assist core facilities with management of economic, regulatory and performance issues. In order to facilitate greater interaction between and among core scientists and administrators, the mission of the CAN-CC is to contribute to the common interests of core administrators, and promote interactions with core scientists in a collegial and productive manner. The specific goals of the Core Administrators Network Coordinating Committee (CANCC) are: to identify and reach out to our target community; provide opportunities for networking; and assess goals for program focus and development.

  17. Core-Noise Research

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2012-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015 (N+1), 2020 (N+2), and 2025 (N+3) timeframes; SFW strategic thrusts and technical challenges; SFW advanced subsystems that are broadly applicable to N+3 vehicle concepts, with an indication where further noise research is needed; the components of core noise (compressor, combustor and turbine noise) and a rationale for NASA's current emphasis on the combustor-noise component; the increase in the relative importance of core noise due to turbofan design trends; the need to understand and mitigate core-noise sources for high-efficiency small gas generators; and the current research activities in the core-noise area, with additional details given about forthcoming updates to NASA's Aircraft Noise Prediction Program (ANOPP) core-noise prediction capabilities, two NRA efforts (Honeywell International, Phoenix, AZ and University of Illinois at Urbana-Champaign, respectively) to improve the understanding of core-noise sources and noise propagation through the engine core, and an effort to develop oxide/oxide ceramic-matrix-composite (CMC) liners for broadband noise attenuation suitable for turbofan-core application. Core noise must be addressed to ensure that the N+3 noise goals are met. Focused, but long-term, core-noise research is carried out to enable the advanced high-efficiency small gas-generator subsystem, common to several N+3 conceptual designs, needed to meet NASA's technical challenges. Intermediate updates to prediction tools are implemented as the understanding of the source structure and engine-internal propagation effects is improved. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Quiet-Aircraft Subproject aims to develop concepts and technologies to reduce perceived community noise attributable to aircraft with minimal impact on weight and performance. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic.

  18. Design analysis of the molten core confinement within the reactor vessel in the case of severe accidents at nuclear power plants equipped with a reactor of the VVER type

    NASA Astrophysics Data System (ADS)

    Zvonaryov, Yu. A.; Budaev, M. A.; Volchek, A. M.; Gorbaev, V. A.; Zagryazkin, V. N.; Kiselyov, N. P.; Kobzar', V. L.; Konobeev, A. V.; Tsurikov, D. F.

    2013-12-01

    The present paper reports the results of the preliminary design estimate of the behavior of the core melt in vessels of reactors of the VVER-600 and VVER-1300 types (a standard optimized and informative nuclear power unit based on VVER technology—VVER TOI) in the case of beyond-design-basis severe accidents. The basic processes determining the state of the core melt in the reactor vessel are analyzed. The concept of molten core confinement within the vessel based on the idea of outside cooling is discussed. Basic assumptions and models, as well as the results of calculation of the interaction between molten materials of the core and the wall of the reactor vessel performed by means of the SOCRAT severe accident code, are presented and discussed. On the basis of the data obtained, the requirements on the operation of the safety systems are determined, upon the fulfillment of which there will appear potential prerequisites for implementing the concept of the confinement of the core melt within the reactor in cases of severe accidents at nuclear power plants equipped with VVER reactors.

  19. Design of functionalized lipids and evidence for their binding to photosystem II core complex by oxygen evolution measurements, atomic force microscopy, and scanning near-field optical microscopy.

    PubMed Central

    Trudel, E; Gallant, J; Mons, S; Mioskowski, C; Lebeau, L; Jeuris, K; Foubert, P; De Schryver, F; Salesse, C

    2001-01-01

    Photosystem II core complex (PSII CC) absorbs light energy and triggers a series of electron transfer reactions by oxidizing water while producing molecular oxygen. Synthetic lipids with different alkyl chains and spacer lengths bearing functionalized headgroups were specifically designed to bind the Q(B) site and to anchor this large photosynthetic complex (240 kDa) in order to attempt two-dimensional crystallization. Among the series of different compounds that have been tested, oxygen evolution measurements have shown that dichlorophenyl urea (DCPU) binds very efficiently to the Q(B) site of PSII CC, and therefore, that moiety has been linked covalently to the headgroup of synthetic lipids. The analysis of the monolayer behavior of these DCPU-lipids has allowed us to select ones bearing long spacers for the anchoring of PSII CC. Oxygen evolution measurements demonstrated that these long-spacer DCPU-lipids specifically bind to PSII CC and inhibit electron transfer. With the use of atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM), it was possible to visualize domains of PSII CC bound to DCPU-lipid monolayers. SNOM imaging has enabled us to confirm that domains observed by AFM were composed of PSII CC. Indeed, the SNOM topography images presented similar domains as those observed by AFM, but in addition, it allowed us to determine that these domains are fluorescent. Electron microscopy of these domains, however, has shown that the bound PSII CC was not crystalline. PMID:11423438

  20. MCNP LWR Core Generator

    SciTech Connect

    Fischer, Noah A. [Los Alamos National Laboratory

    2012-08-14

    The reactor core input generator allows for MCNP input files to be tailored to design specifications and generated in seconds. Full reactor models can now easily be created by specifying a small set of parameters and generating an MCNP input for a full reactor core. Axial zoning of the core will allow for density variation in the fuel and moderator, with pin-by-pin fidelity, so that BWR cores can more accurately be modeled. LWR core work in progress: (1) Reflectivity option for specifying 1/4, 1/2, or full core simulation; (2) Axial zoning for moderator densities that vary with height; (3) Generating multiple types of assemblies for different fuel enrichments; and (4) Parameters for specifying BWR box walls. Fuel pin work in progress: (1) Radial and azimuthal zoning for generating further unique materials in fuel rods; (2) Options for specifying different types of fuel for MOX or multiple burn assemblies; (3) Additional options for replacing fuel rods with burnable poison rods; and (4) Control rod/blade modeling.

  1. We present the design and development of Corelyzer, an initial visual core description tool with collaboration and annotation features. Corelyzer belongs

    E-print Network

    Johnson, Andrew

    , visualize and manage high-resolution core images gathered during core drilling expeditions. We have been observing scientists using Corelyzer over several drilling expeditions to better understand how to integrate and capabilities. For example, Josh Reed, IT manager of the Antarctica geological drilling project, developed

  2. Collapse mechanisms of sandwich beams with composite faces and a foam core, loaded in three-point bending. Part I: analytical models and minimum weight design

    Microsoft Academic Search

    Craig A. Steeves; Norman A. Fleck

    2004-01-01

    Analytical predictions are made for the three-point bending collapse strength of sandwich beams with composite faces and polymer foam cores. Failure is by the competing modes of face sheet microbuckling, plastic shear of the core, and face sheet indentation beneath the loading rollers. Particular attention is paid to the development of an indentation model for elastic faces and an elastic–plastic

  3. Testing embedded-core based system chips

    Microsoft Academic Search

    Yervant Zorian; Erik Jan Marinissen; Sujit Dey

    1998-01-01

    Advances in semiconductor process and design technology enable the design of complex system chips. Traditional IC design, in which every circuit is designed from scratch and reuse is limited to standard-cell libraries, is more and more replaced by a design style based on embedding large reusable modules, the so-called cores. This core-based design poses a series of new challenges, especially

  4. Place-based research project design for 10-week REU and two-week "mini-REU" internships using lake sediment cores

    NASA Astrophysics Data System (ADS)

    Myrbo, A.; Howes, T.; Thompson, R.; Drake, C.; Woods, P.; Schuldt, N.; Borkholder, B.; Marty, J.; Lafrancois, T.; Pellerin, H.

    2012-12-01

    Lake sediment cores provide scalable, interdisciplinary research projects that are well suited for summer internships such as the NSF-REU (Research Experience for Undergraduates). Short paleorecords (100-500 years or about a meter of core) are easy to collect and are tractable in terms of sample numbers (Myrbo et al. 2011). Many students find it compelling to reconstruct the recent past; choosing sites with cultural or historical significance is another way to make research seem more relevant. We present the results and experiences of designing two- and ten-week individual, group, and team research projects. Each of these projects contributes to the findings of a collaborative inquiry by the Fond du Lac Band of Lake Superior Chippewa (FDL) and the University of Minnesota (UMN). Research questions are determined and framed by FDL Resource Management, and student projects are supported and advised by both FDL and UMN scientists. The research is focused on the past environmental conditions of on- and off-Reservation wild rice lakes and the surrounding landscapes and people, and includes the study of biological and chemical proxies as well as historical records. Over the past three years, this approach has enabled diverse groups of students to conduct authentic and original basic research that also has applications to management and planning issues for Tribal resource managers, and to develop skills that are portable to other management and academic settings. These compelling "short" time scale projects can serve as a gateway for students to further pursue science including longer term paleorecords, climate change research, other disciplines in ecology, water resources, geography, archeology, and geology, as well as humanities research areas such as history and landscape architecture. An overarching goal is to help students understand current environmental change in the context of long-term changes, pre-industrial human land use, and accelerated Anthropocene impacts. The two-week "mini-REU" was designed to attract students with little or no independent research experience, who might be intimidated by applying for a ten-week internship away from home (but who might apply for one after completing a good mini-REU). The arc of research, from site selection to field work and lab work to data interpretation and poster presentation, must be encompassed in these brief projects, so group projects with clear goals are best suited for mini-REUs. The May 2012 project, with twelve students in four research proxy groups (charcoal, phytoliths, plant macrofossils, and zooplankton), demonstrated that a FDL lake, Rice Portage, had extensive wild rice habitat prior to early 20th-century Euroamerican ditching; this proof was required in order for FDL to gain a permit from the Army Corps of Engineers to raise the lake level as part of a wild rice restoration effort. Each proxy group had one research advisor (a graduate student or soft money researcher), plus one UMN über-advisor for the project as a whole, as well as the Fond du Lac resource manager. All of these advisors also work with the 10-week interns throughout the summer.

  5. Core Noise Reduction

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduce-Perceived-Noise Technical Challenge; and the current research activities in the core noise area. Recent work1 on the turbine-transmission loss of combustor noise is briefly described, two2,3 new NRA efforts in the core-noise area are outlined, and an effort to develop CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is delineated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries.

  6. Engineering Technology Core (ET Core) Guide

    NSDL National Science Digital Library

    "The ET Core is designed to prepare students for the study of courses specific to any engineering technology major. The curriculum provides hands-on work with technology and workplace relevance as students complete their study of physics, communications, and mathematics (through introductory calculus)." In this 140-page PDF, visitors will find an introduction to the course, the competencies it covers, equipment needed, and detailed instructions for all sixteen modules. The modules cover all sorts of engineering technology including Electrical, Thermal, Mechanical, Fluids, Optics, and Materials. Each module also contains any students handouts necessary to teach it.

  7. Design optimization of a dual-core dispersion-compensating fiber with a high figure of merit and a large effective area for dense wavelength-division multiplexed transmission through standard G.655 fibers

    Microsoft Academic Search

    Kamna Pande; Bishnu P. Pal

    2003-01-01

    We report design optimization in terms of index-profile parameters of a dual-core dispersion-slope-compensating fiber suitable for broadband dispersion compensation in standard G.655 and G.655b single-mode fibers over the C and L bands of fiber amplifiers and additionally over the S band for the G.655b fibers. It takes into account profiles that can be achieved with state-of-the-art fabrication techniques such as

  8. Matrix Acidizing Parallel Core Flooding Apparatus 

    E-print Network

    Ghosh, Vivek

    2013-07-23

    , assemble, and test a matrix acidizing parallel core flooding apparatus. The apparatus was rated for 5,000 psi and 250 ?F. The design uses 36 valves to configure small, medium, and large core holders. The key feature is the ability to run parallel core... ................................................................................. 27 2.10 Nitrogen Source ............................................................................................ 29 2.11 Fraction Collector ......................................................................................... 30 2.12 Valve...

  9. Fissioning Plasma Core Reactor

    NASA Technical Reports Server (NTRS)

    Albright, Dennis; Butler, Carey; West, Nicole; Cole, John W. (Technical Monitor)

    2002-01-01

    Institute for Scientific Research, Inc. (ISR) research program consist of: 1.Study core physics by adapting existing codes: MCNP4C - Monte Carlo code; COMBINE/VENTURE - diffusion theory; SCALE4 - Monte Carlo, with many utility codes. 2. Determine feasibility and study major design parameters: fuel selection, temperature and reflector sizing. 3. Study reactor kinetics: develop QCALC1 to model point kinetics; study dynamic behavior of the power release.

  10. CopperCore Service Integration

    ERIC Educational Resources Information Center

    Vogten, Hubert; Martens, Harrie; Nadolski, Rob; Tattersall, Colin; van Rosmalen, Peter; Koper, Rob

    2007-01-01

    In an e-learning environment there is a need to integrate various e-learning services like assessment services, collaboration services, learning design services and communication services. In this article we present the design and implementation of a generic integrative service framework, called CopperCore Service Integration (CCSI). We will…

  11. ADVANCEMENTS IN ENGINEERED COMPOSITE SANDWICH CORE MATERIALS

    Microsoft Academic Search

    Eric J. Lang

    Results are presented for product and design innova tions involving TYCOR ® fiber-reinforced- foam (FRF) core technology for composite sandwich construction. Low-cost FRF core-preforms used with infusion molding processes provide light, stiff composite sandwich panels and structures. Product design innovations were tested that provide more balanced primary (\\

  12. Designing An Efficient Kernel-level and User-level Hybrid Approach for MPI Intra-node Communication on Multi-core Systems

    E-print Network

    Panda, Dhabaleswar K.

    -assisted direct copy. We use an Intel quad-core cluster for our study. We first run micro- benchmarks to analyze the performance of MPI collective operations by up to 60%, and applications by up to 17%. 1 Introduction Cluster; and equipment donations from Intel, Mellanox, AMD, Apple, Appro, Dell, Microway, PathScale, IBM, Silver- Storm

  13. Uranium droplet core nuclear rocket

    NASA Technical Reports Server (NTRS)

    Anghaie, Samim

    1991-01-01

    Uranium droplet nuclear rocket is conceptually designed to utilize the broad temperature range ofthe liquid phase of metallic uranium in droplet configuration which maximizes the energy transfer area per unit fuel volume. In a baseline system dissociated hydrogen at 100 bar is heated to 6000 K, providing 2000 second of Isp. Fission fragments and intense radian field enhance the dissociation of molecular hydrogen beyond the equilibrium thermodynamic level. Uranium droplets in the core are confined and separated by an axisymmetric vortex flow generated by high velocity tangential injection of hydrogen in the mid-core regions. Droplet uranium flow to the core is controlled and adjusted by a twin flow nozzle injection system.

  14. Geomagnetism of earth's core

    NASA Technical Reports Server (NTRS)

    Benton, E. R.

    1983-01-01

    Instrumentation, analytical methods, and research goals for understanding the behavior and source of geophysical magnetism are reviewed. Magsat, launched in 1979, collected global magnetometer data and identified the main terrestrial magnetic fields. The data has been treated by representing the curl-free field in terms of a scalar potential which is decomposed into a truncated series of spherical harmonics. Solutions to the Laplace equation then extend the field upward or downward from the measurement level through intervening spaces with no source. Further research is necessary on the interaction between harmonics of various spatial scales. Attempts are also being made to analytically model the main field and its secular variation at the core-mantle boundary. Work is also being done on characterizing the core structure, composition, thermodynamics, energetics, and formation, as well as designing a new Magsat or a tethered satellite to be flown on the Shuttle.

  15. The BubbleWrap many-core: popping cores for sequential acceleration

    Microsoft Academic Search

    Ulya R. Karpuzcu; Brian Greskamp; Josep Torrellas

    2009-01-01

    Many-core scaling now faces a power wall. The gap between the number of cores that fit on a die and the number that can operate simultaneously under the power budget is rapidly increasing with technology scaling. In future designs, many of the cores may have to be dormant at any given time to meet the power budget. To push back

  16. Properties of Reset Cores in Radar Pulse Transformers

    Microsoft Academic Search

    Reuben Lee

    1962-01-01

    This paper outlines permeability and loss measurements on large uncut toroidal cores of Hipersil and Supermendur alloys. With forced cooling, large increments of core induction can be utilized; with a reset core, pulse permeability is much higher than it is in cut cores, and alters pulse transformer design radically. At inductions up to 24 kgauss, pulse permeability of fully oriented

  17. Development of new and improvement of existing core recovery methods

    Microsoft Academic Search

    C. Marx; E. J. Kroemer

    1982-01-01

    Prospecting of new oil and gas fields through sampling of soil by core drilling was investigated. Two core recovery methods were designed; corresponding prototypes were built and tested. The drill mandrel, the core barrel closing system, solliciation of the barrel by hydraulic friction, and sollicitation of the driving axe during side drilling were studied. The core barrel system with built

  18. Hollow-core tapered coupler for large inner diameter hollow-core optical fibers

    Microsoft Academic Search

    Guiyao Zhou; Zhiyun Hou; Lantian Hou; Jigang Liu

    2003-01-01

    A novel hollow-core tapered coupler has been theoretically designed and fabricated by fiber drawing machine. The coupler's inner wall is coated with a polycrystalline GeO2 film. The coupling loss of hollow-core tapered coupler is about 0.2 dB. Hollow-core tapered coupler reduces the transmission loss of hollow-core optical fiber (HCOF) by 0.5 dB\\/m, therefore the coupler is suitable for coupling high

  19. Core Recursive Hierarchical Image Segmentation

    NASA Technical Reports Server (NTRS)

    Tilton, James

    2011-01-01

    The Recursive Hierarchical Image Segmentation (RHSEG) software has been repackaged to provide a version of the RHSEG software that is not subject to patent restrictions and that can be released to the general public through NASA GSFC's Open Source release process. Like the Core HSEG Software Package, this Core RHSEG Software Package also includes a visualization program called HSEGViewer along with a utility program HSEGReader. It also includes an additional utility program called HSEGExtract. The unique feature of the Core RHSEG package is that it is a repackaging of the RHSEG technology designed to specifically avoid the inclusion of the certain software technology. Unlike the Core HSEG package, it includes the recursive portions of the technology, but does not include processing window artifact elimination technology.

  20. Acceptance test procedure for core sample trucks

    Microsoft Academic Search

    1995-01-01

    The purpose of this Acceptance Test Procedure is to provide instruction and documentation for acceptance testing of the rotary mode core sample trucks, HO-68K-4600 and HO-68K-4647. The rotary mode core sample trucks were based upon the design of the second core sample truck (HO-68K-4345) which was constructed to implement rotary mode sampling of the waste tanks at Hanford. Acceptance testing

  1. Superconducting air-core transformers and their electromagnetic analysis

    Microsoft Academic Search

    Xiaoyuan Chen; Jianxun Jin

    2009-01-01

    This paper provides a brief summary on various superconducting air-core transformers. The structural optimizations of the high temperature superconducting (HTS) air-core windings and relevant electromagnetic analysis have also been presented to achieve practical prototype design.

  2. An Overview of Project CORES.

    ERIC Educational Resources Information Center

    Reynolds, Bill J.

    This paper describes the activities of Project Covert and Overt Responses to Education Simulation (CORES) designed to provide an identity for students and faculty desiring to engage in simulation-related research and development activities. Activities for investigating the use of simulation are in the directions of administrative decision making,…

  3. Excitement in Core Curriculum Classes.

    ERIC Educational Resources Information Center

    Hammons-Bryner, Sue; Robinson, Bobbie

    1994-01-01

    An interdisciplinary, team-taught community college course combining American literature, writing instruction, and American history was designed to challenge students and eliminate some core curriculum problems. Emphasis on motivation and team teaching were successful in raising student achievement and enthusiasm. Course improvement is ongoing.…

  4. European research on HLM thermal-hydraulics for ADS applications

    NASA Astrophysics Data System (ADS)

    Roelofs, F.; de Jager, B.; Class, A.; Jeanmart, H.; Schuurmans, P.; Ciampichetti, A.; Gerbeth, G.; Stieglitz, R.; Fazio, C.

    2008-06-01

    The objective of the European 6th framework project EUROTRANS is to demonstrate the technical feasibility of transmutation of high level nuclear waste using accelerator driven systems. Within this objective the design of a European experimental ADS should demonstrate the technical feasibilities to transmute a sizeable amount of waste and to operate an ADS safely. This ADS will be a subcritical reactor system having liquid lead-bismuth eutectic as coolant. The liquid lead-bismuth eutectic is also intended to serve as target material for the spallation reaction which forms a crucial part to the subcritical reactor core. Since lead-bismuth eutectic is used as core coolant and spallation material, knowledge of its thermal hydraulic behaviour is essential. Within the DEMETRA domain of the EUROTRANS project, basic thermal hydraulic studies in order to support the design and safety analysis of XT-ADS components and the development of measurement techniques have been started.

  5. Hollow core photonic crystal fibers for beam delivery

    Microsoft Academic Search

    Georges Humbert; J. C. Knight; G. Bouwmans; P. St. J. Russell; D. P. Williams; P. J. Roberts; B. J. Mangan

    2004-01-01

    Hollow-core photonic crystal fibers have unusual properties which make them ideally suited to delivery of laser beams. We describe the properties of fibers with different core designs, and the observed effects of anti-crossings with interface modes. We conclude that 7-unit-cell cores are currently most suitable for transmission of femtosecond and sub-picosecond pulses, whereas larger cores (e.g. 19-cell cores) are better

  6. Supramolecular immobilization of glucose oxidase on gold coated with cyclodextrin-modified cysteamine core PAMAM G-4 dendron/Pt nanoparticles for mediatorless biosensor design.

    PubMed

    Díez, Paula; Piuleac, Ciprian-George; Martínez-Ruiz, Paloma; Romano, Santiago; Gamella, María; Villalonga, Reynaldo; Pingarrón, José M

    2013-04-01

    Cysteamine core polyamidoamine G-4 dendron branched with ?-cyclodextrins was chemisorbed on the surface of Au electrodes and further coated with Pt nanoparticles. Adamantane-modified glucose oxidase was subsequently immobilized on the nanostructured electrode surface by supramolecular association. This enzyme electrode was used to construct a reagentless amperometric biosensor for glucose, making use of the electrochemical oxidation of H2O2 generated in the enzyme reaction. The amperometric response of the biosensor was rapid (6 s) and a linear function of glucose concentration between 5 and 705 ?mol L(-1). The biosensor had a low detection limit of 2.0 ?mol L(-1), sensitivity of 197 mA mol(-1) L cm(-2), and retained 94% of its initial response after storage for nine days at 4 °C. PMID:23090651

  7. Design.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    Provides an annotated bibliography of resources on this month's theme "Design" for K-8 language arts, art and architecture, music and dance, science, math, social studies, health, and physical education. Includes Web sites, CD-ROMs and software, videos, books, audiotapes, magazines, professional resources and classroom activities. Features Art…

  8. Velocity-Controlled Magnetic Bearings with Solid Cores

    NASA Technical Reports Server (NTRS)

    Chen, H. Ming; Walton, James

    1996-01-01

    A methodology for designing velocity-controlled magnetic bearings with laminated cores has been extended to those with solid cores. The eddy-current effect of the solid cores is modeled as an opposing magnetomotive force. The bearing control dynamics is formulated in a dimensionless fashion which can be readily reviewed on a root-locus plot for stability. This facilitates the controller design and tuning process for solid core magnetic bearings using no displacement sensors.

  9. Droplet Core Nuclear Rocket (DCNR)

    NASA Technical Reports Server (NTRS)

    Anghaie, Samim

    1991-01-01

    The most basic design feature of the droplet core nuclear reactor is to spray liquid uranium into the core in the form of droplets on the order of five to ten microns in size, to bring the reactor to critical conditions. The liquid uranium fuel ejector is driven by hydrogen, and more hydrogen is injected from the side of the reactor to about one and a half meters from the top. High temperature hydrogen is expanded through a nozzle to produce thrust. The hydrogen pressure in the system can be somewhere between 50 and 500 atmospheres; the higher pressure is more desirable. In the lower core region, hydrogen is tangentially injected to serve two purposes: (1) to provide a swirling flow to protect the wall from impingement of hot uranium droplets: (2) to generate a vortex flow that can be used for fuel separation. The reactor is designed to maximize the energy generation in the upper region of the core. The system can result in and Isp of 2000 per second, and a thrust-to-weight ratio of 1.6 for the shielded reactor. The nuclear engine system can reduce the Mars mission duration to less than 200 days. It can reduce the hydrogen consumption by a factor of 2 to 3, which reduces the hydrogen load by about 130 to 150 metric tons.

  10. Core performance tests for the JOYO MK-III upgrade

    Microsoft Academic Search

    Takafumi Aoyama; Takashi Sekine; Shigetaka Maeda; Akihiro Yoshida; Yukimoto Maeda; Soju Suzuki; Toshikazu Takeda

    2007-01-01

    Many changes were made in the recent upgrade of the experimental fast reactor JOYO to the MK-III design. The core changes which were made to achieve a four-fold increase in irradiation capacity includes the introduction of a second enrichment zone, an increase in core radius and a decrease in core height. Performance tests done at low power, during the rise

  11. Comparing the Common Core State Standards in Mathematics and the NAEP Framework. Achieving the Common Core

    ERIC Educational Resources Information Center

    Achieve, Inc., 2010

    2010-01-01

    Through the Common Core State Standards (CCSS) Initiative, states and territories have collaborated in the development of a common core of standards in English Language Arts and mathematics for grades kindergarten through twelve that are now being adopted by states. Designed not only for the purpose of providing strong, shared expectations, the…

  12. Multi-Core Processor Memory Contention Benchmark Analysis Case Study

    NASA Technical Reports Server (NTRS)

    Simon, Tyler; McGalliard, James

    2009-01-01

    Multi-core processors dominate current mainframe, server, and high performance computing (HPC) systems. This paper provides synthetic kernel and natural benchmark results from an HPC system at the NASA Goddard Space Flight Center that illustrate the performance impacts of multi-core (dual- and quad-core) vs. single core processor systems. Analysis of processor design, application source code, and synthetic and natural test results all indicate that multi-core processors can suffer from significant memory subsystem contention compared to similar single-core processors.

  13. Exploiting tightly-coupled cores

    E-print Network

    Bates, Daniel; Bradbury, Alex; Koltes, Andreas; Mullins, Robert

    2014-08-26

    Journal of Signal Processing Systems manuscript No. (will be inserted by the editor) Exploiting Tightly-Coupled Cores Daniel Bates · Alex Bradbury · Andreas Koltes · Robert Mullins Received: date / Accepted: date Abstract The individual processors... packet cache, register file, and L1 cache banks. The design is conservatively margined at the WC corner including foundry recommendations for on-chip variation and clock jitter. Our clock period is ?42 FO4 delays: within the typi- cal range of 40-60 FO4...

  14. National Ice Core Laboratory

    NSDL National Science Digital Library

    USGS

    This facility stores, curates and studies ice cores recovered from glaciers from around the world. The site provides a photo gallery and description about each step of the process of drilling, transporting and analyzing the core. There is also a database of basic information about each core held at the laboratory and links to global change research information.

  15. Cores of combined games

    Microsoft Academic Search

    Francis Bloch; Geoffroy De Clippel

    2008-01-01

    This paper studies the core of combined games, obtained by summing two coalitional games. It is shown that the set of balanced transferable utility games can be partitioned into equivalence classes of component games whose core is equal to the core of the combined game. On the other hand, for non balanced games, the binary relation associating two component games

  16. Cores of Combined Games

    Microsoft Academic Search

    Francis Bloch; Geoffroy de Clippel

    2009-01-01

    This paper studies the core of combined games, obtained by summing two coalitional games. It is shown that the set of balanced transferable utility games can be partitioned into equivalence classes of component games to determine whether the core of the combined game coincides with the sum of the cores of its components. On the other hand, for non-balanced games,

  17. Banded transformer cores

    NASA Technical Reports Server (NTRS)

    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.

  18. Design of a Naturally Cooled High Frequency Integrated Magnetic Aiman KERIM, Jean Paul FERRIEUX, James ROUDET and Stphane CATELLANI

    E-print Network

    Paris-Sud XI, Université de

    Design of a Naturally Cooled High Frequency Integrated Magnetic Component Aiman KERIM, Jean Paul design tools recently developed for designing magnetic component. I. INTRODUCTION Automated conception magnetic component. III. DESIGN CONSIDERATIONS A. Core specifications 1. Core material A core material

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

    NASA Technical Reports Server (NTRS)

    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.

  20. An integrated ARM and multi-core DSP simulator

    Microsoft Academic Search

    Sharad Singhai; Ming-Yung Ko; Sanjay Jinturkar; Mayan Moudgill; John Glossner

    2007-01-01

    In this paper we describe the design and implementation of a flexible, and extensible, just-in-time ARM simulator designed to run co-operatively with a multi-core DSP sim- ulator on x86 hosts. The integrated simulator can boot ARM\\/Linux alongside another operating system running on DSP cores, thus truly supporting a heterogeneous multi-core operating environment. In addition, the simulator facili- tates exploration of

  1. A comparison of micromachined inductors with different magnetic core materials

    Microsoft Academic Search

    Jae Y. Park; Mark G. Allen

    1996-01-01

    Two integrated inductors with different electroplated cores, permalloy (Ni(80%)-Fe(20%)) and orthonol (Ni(50%)-Fe(50%)) cores, are designed, fabricated, tested, and compared in order to reach optimum designs for integrated inductors and transformers. These integrated inductors were realized on a silicon wafer by using micromachining techniques to fabricate wrapped coils wound around a `bar' of high permeability core material. These devices have high

  2. Low loss broadband transmission in hypocycloid-core Kagome hollow-core photonic crystal fiber.

    PubMed

    Wang, Y Y; Wheeler, N V; Couny, F; Roberts, P J; Benabid, F

    2011-03-01

    We report on the fabrication of a seven-cell-core and three-ring-cladding large-pitch Kagome-lattice hollow-core photonic crystal fiber (HC-PCF) with a hypocycloid-shaped core structure. We demonstrate experimentally and theoretically that the design of this core shape enhances the coupling inhibition between the core and cladding modes and offers optical attenuation with a baseline of ?180?dB/km over a transmission bandwidth larger than 200?THz. This loss figure rivals the state-of-the-art photonic bandgap HC-PCF while offering an approximately three times larger bandwidth and larger mode areas. Also, it beats the conventional circular-core-shaped Kagome HC-PCF in terms of the loss. The development of this novel (to our knowledge) HC-PCF has potential for a number of applications in which the combination of a large optical bandwidth and a low loss is a prerequisite. PMID:21368943

  3. 2432 IEEE TRANSACTIONS ON MAGNETICS, VOL. 41, NO. 9, SEPTEMBER 2005 Effective Parameters for Toroidal Cores Based on

    E-print Network

    Vu-Quoc, Loc

    , soft magnetic materials. I. INTRODUCTION TO facilitate its design and application, a magnetic core to approximate the initial magnetization curve. Material-independent, geometry-dependent expressions by core producers. Index Terms--Ferrites, ferrimagnetic materials, magnetic cores, magnetic hysteresis

  4. ART AND DESIGN All students enrolling in the School

    E-print Network

    ART AND DESIGN All students enrolling in the School of Art and Design begin their studies in a Pre-Art and Design Core program designed to introduce them to the fundamentals of the field. Pre-Art and Design Core-faculty and student-to-student interaction. Faculty in the Pre-Art and Design Core program work closely with students

  5. The CORE study protocol: a stepped wedge cluster randomised controlled trial to test a co-design technique to optimise psychosocial recovery outcomes for people affected by mental illness in the community mental health setting

    PubMed Central

    Palmer, Victoria J; Chondros, Patty; Piper, Donella; Callander, Rosemary; Weavell, Wayne; Godbee, Kali; Potiriadis, Maria; Richard, Lauralie; Densely, Konstancja; Herrman, Helen; Furler, John; Pierce, David; Schuster, Tibor; Iedema, Rick; Gunn, Jane

    2015-01-01

    Introduction User engagement in mental health service design is heralded as integral to health systems quality and performance, but does engagement improve health outcomes? This article describes the CORE study protocol, a novel stepped wedge cluster randomised controlled trial (SWCRCT) to improve psychosocial recovery outcomes for people with severe mental illness. Methods An SWCRCT with a nested process evaluation will be conducted over nearly 4?years in Victoria, Australia. 11 teams from four mental health service providers will be randomly allocated to one of three dates 9?months apart to start the intervention. The intervention, a modified version of Mental Health Experience Co-Design (MH ECO), will be delivered to 30 service users, 30 carers and 10 staff in each cluster. Outcome data will be collected at baseline (6?months) and at completion of each intervention wave. The primary outcome is improvement in recovery score using the 24-item Revised Recovery Assessment Scale for service users. Secondary outcomes are improvements to user and carer mental health and well-being using the shortened 8-item version of the WHOQOL Quality of Life scale (EUROHIS), changes to staff attitudes using the 19-item Staff Attitudes to Recovery Scale and recovery orientation of services using the 36-item Recovery Self Assessment Scale (provider version). Intervention and usual care periods will be compared using a linear mixed effects model for continuous outcomes and a generalised linear mixed effects model for binary outcomes. Participants will be analysed in the group that the cluster was assigned to at each time point. Ethics and dissemination The University of Melbourne, Human Research Ethics Committee (1340299.3) and the Federal and State Departments of Health Committees (Project 20/2014) granted ethics approval. Baseline data results will be reported in 2015 and outcomes data in 2017. Trial registration number Australian and New Zealand Clinical Trials Registry ACTRN12614000457640. PMID:25805530

  6. Adaptive core simulation

    NASA Astrophysics Data System (ADS)

    Abdel-Khalik, Hany Samy

    The work presented in this thesis is a continuation of a master's thesis research project conducted by the author to gain insight into the applicability of inverse methods to developing adaptive simulation capabilities for core physics problems. Use of adaptive simulation is intended to improve the fidelity and robustness of important core attributes predictions such as core power distribution, thermal margins and core reactivity. Adaptive simulation utilizes a selected set of past and current reactor measurements of reactor observables, i.e. in-core instrumentations readings, to adapt the simulation in a meaningful way. A meaningful adaption will result in high fidelity and robust adapted core simulators models. To perform adaption, we propose an inverse theory approach in which the multitudes of input data to core simulators, i.e. reactor physics and thermal-hydraulic data, are to be adjusted to improve agreement with measured observables while keeping core simulators models unadapted. At a first glance, devising such adaption for typical core simulators models would render the approach impractical. This follows, since core simulators are based on very demanding computational models, i.e. based on complex physics models with millions of input data and output observables. This would spawn not only several prohibitive challenges but also numerous disparaging concerns. The challenges include the computational burdens of the sensitivity-type calculations required to construct Jacobian operators for the core simulators models. Also, the computational burdens of the uncertainty-type calculations required to estimate the uncertainty information of core simulators input data presents a demanding challenge. The concerns however are mainly related to the reliability of the adjusted input data. We demonstrate that the power of our proposed approach is mainly driven by taking advantage of this unfavorable situation. Our contribution begins with the realization that to obtain numerical solutions to demanding computational models, matrix methods are often employed to produce approximately equivalent discretized computational models that may be manipulated further by computers. The discretized models are described by matrix operators that are often rank-deficient, i.e. ill-posed. We introduce a novel set of matrix algorithms, denoted by Efficient Subspace Methods (ESM), intended to approximate the action of very large, dense, and numerically rank-deficient matrix operators. We demonstrate that significant reductions in both computational and storage burdens can be attained for a typical BWR core simulator adaption problem without compromising the quality of the adaption. We demonstrate robust and high fidelity adaption utilizing a virtual core, e.g. core simulator predicted observables with the virtual core either based upon a modified version of the core simulator whose input data are to be adjusted or an entirely different core simulator. Further, one specific application of ESM is demonstrated, that is being the determination of the uncertainties of important core attributes such as core reactivity and core power distribution due to the available ENDF/B cross-sections uncertainties. The use of ESM is however not limited to adaptive core simulation techniques only, but a wide range of engineering applications may easily benefit from the introduced algorithms, e.g. machine learning and information retrieval techniques highly depends on finding low rank approximations to large scale matrices. In the appendix, we present a stand-alone paper that presents a generalized framework for ESM, including the mathematical theory behind the algorithms and several demonstrative applications that are central to many engineering arenas---(a) sensitivity analysis, (b) parameter estimation, and (c) uncertainty analysis. We choose to do so to allow other engineers, applied mathematicians, and scientists from other scientific disciplines to take direct advantage of ESM without having to sail across the sea of reactor core calculations.

  7. Multi Core Design for Chip Level Multiprocessing

    NASA Astrophysics Data System (ADS)

    Fossum, Tryggve

    Chip level integration continues to be a driving force in the computer industry. It lowers the cost and increases performance of computer systems, creating a remarkable rate of improvement in all processors, from handheld devices to supercomputers. Processor chips now (in 2009) contain up to two billion transistors. Gordon Moore outlined a roadmap for chip level integration in 1965, which has become known as Moore's Law. It predicts that the density of transistors in a silicon chip will double every process generation. It has become the heartbeat of the semiconductor industry.

  8. Designing Professional Development around the Common Core

    E-print Network

    Belding, Juliana

    `reading' texts and papers on our own? Through research in undergrad, grad and postgrad? Through hands in the "processes and proficiencies" of, for eg., NCTM Process Standards, 2000 National Research Council's Adding individual, not limited to a single list Usually not explicitly taught (no `Math Research Methods' course

  9. Simplified hollow-core photonic crystal fiber.

    PubMed

    Gérôme, Frédéric; Jamier, Raphaël; Auguste, Jean-Louis; Humbert, Georges; Blondy, Jean-Marc

    2010-04-15

    An original design of hollow-core photonic crystal fiber composed of a thin silica ring suspended in air by six silica struts is proposed. This structure can be viewed as a simplified Kagomé-lattice fiber reduced to one layer of air holes. By working on the core surround parameters, an efficient antiresonant air guiding was successfully demonstrated. Two large low-loss windows (visible/IR) were measured with a minimum attenuation less than 0.2 dB radicalm at yellow wavelengths, comparable with state-of-the-art designs. The curvature behavior was also studied, showing low bending loss sensitivity for the fundamental transmission band. These relevant features might open a new route to propose original hollow-core fiber designs while making their production simpler and faster than previously. PMID:20410951

  10. Development of new and improvement of existing core recovery methods

    NASA Astrophysics Data System (ADS)

    Marx, C.; Kroemer, E. J.

    1982-06-01

    Prospecting of new oil and gas fields through sampling of soil by core drilling was investigated. Two core recovery methods were designed; corresponding prototypes were built and tested. The drill mandrel, the core barrel closing system, solliciation of the barrel by hydraulic friction, and sollicitation of the driving axe during side drilling were studied. The core barrel system with built in hydrostatic drill motor and diamond bit drill was retained. This combination leads to a core sample recovery rate of over 90% and a drill speed increase of 40% over the rotary core sampling system. The KIBM-1 prototype was tested in five drilling applications in deep wells. The sidewall coring system permits recovery of core material from the bore hole wall for boreholes at least eight and a half inches in diameter.

  11. Safety design of prototype fast breeder reactor

    Microsoft Academic Search

    S. B. Bhoje; S. C. Chetal; Om Pal Singh

    2004-01-01

    The basic design and safety design of Prototype Fast Breeder Reactor (PFBR) is presented. Design aspects covered include safety classification, seismic categorization, design basis conditions, design safety limits, core physics, core monitoring, shutdown system, decay heat removal system, protection against sodium leaks and tube leaks in steam generator, plant layout, radiation protection, event analysis, beyond design basis accidents, integrity of

  12. Core Knowledge Resource Guide.

    ERIC Educational Resources Information Center

    Core Knowledge Foundation, Charlottesville, VA.

    This resource guide is an annotated bibliography of books and other print sources relevant to the content specified in the Core Knowledge Sequences for grades 1 through 6, which are curricular guidelines published by the Core Knowledge Foundation. Entries are organized by subject area and grade level. Within each grade and subject area, entries…

  13. Reinforced sand cores

    Microsoft Academic Search

    Martin Zoldan

    2005-01-01

    Engine blocks and cylinder heads (castings) are made of aluminum or cast iron. Molten metal, poured into molds, forms the shape of engine blocks and cylinder heads. Molds create the outside of the casting and sand cores create cavities within the casting. ^ Typically, sand cores must maintain small aspect ratios to preserve structural integrity during the casting process. The

  14. Cores of convex games

    Microsoft Academic Search

    Lloyd S. Shapley

    1971-01-01

    The core of ann-person game is the set of feasible outcomes that cannot be improved upon by any coalition of players. A convex game is defined as one that is based on a convex set function. In this paper it is shown that the core of a convex game is not empty and that it has an especially regular structure.

  15. Secure Core Contact Information

    E-print Network

    Secure Core Contact Information C. E. Irvine irvine@nps.edu 831-656-2461 Department of Computer for the secure management of local and/or remote information in multiple contexts. The SecureCore project Science Graduate School of Operations and Information Sciences www.cisr.nps.edu Project Description

  16. Direct core materials.

    PubMed

    Wilson, Paul H; Fisher, Nigel L; Bartlett, David W

    2003-09-01

    There are many materials that can be used for direct-placement cores. Although the scientific evidence is incomplete, some materials are better suited to this task than others. This article provides an overview of direct-placement core materials and highlights what clinicians should consider when assessing a new product. PMID:14558201

  17. 34. DESPATCH CORE OVENS, GREY IRON FOUNDRY CORE ROOM, BAKES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. DESPATCH CORE OVENS, GREY IRON FOUNDRY CORE ROOM, BAKES CORES THAT ARE NOT MADE ON HEATED OR COLD BOX CORE MACHINES, TO SET BINDING AGENTS MIXED WITH THE SAND CREATING CORES HARD ENOUGH TO WITHSTAND THE FLOW OF MOLTEN IRON INSIDE A MOLD. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  18. Lunar Core and Tides

    NASA Technical Reports Server (NTRS)

    Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

    2004-01-01

    Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.

  19. Structural Performance of Eco-Core Sandwich Panels

    NASA Astrophysics Data System (ADS)

    Shivakumar, Kunigal; Chen, Huanchun

    Eco-Core, a fire resistant core material for sandwich composite structures developed under the US Navy (ONR) program, was used to study its performance as a sandwich beam with glass/vinyl ester face sheet. Performance of Eco-Core was compared with balsa and PVC core sandwich panels. Test specimens were designed to simulate shear, flexural, and edgewise compression loadings. These tests were conducted on Eco-Core as well as balsa and PVC sandwich composite specimens. Failure loads and modes were compared with each other and the analytical prediction. Both Eco-Core and balsa cored sandwich beams had similar failure modes in all three test conditions. In the case of transversely loaded (four-point) beams Eco-Core specimens failed by core shear for span/depth (S/d) ratio less than 4 and the failure mode changed to core tension for S/d >4. This is attributed to weak tensile strength of the core material. An expression for core tension failure load based on beam theory was derived. On the other hand, ductile materials like PVC failed by core indentation. Under edgewise compression, face sheet microbuckling and general buckling are the two potential failure modes for Eco-Core and balsa core sandwich composites. For specimen length/depth ratio L/d <7 the failure is by face sheet microbuckling, for 7 ?L/d ?13 the failure is a combination of face sheet microbuckling, debonding and buckling, and for L/d >13 the failure is by general buckling. Predictions from the existing equations agreed well with the experiment for both core materials. For PVC core, wrinkling/shear buckling and general buckling are the potential failure modes. For L/d ?8.5 the failure is wrinkling and for L/d >8.5 the failure is general buckling.

  20. Daylighting Design

    NSDL National Science Digital Library

    2014-09-18

    Students explore the many different ways that engineers provide natural lighting to interior spaces. They analyze various methods of daylighting by constructing model houses from foam core board and simulating the sun with a desk lamp. Teams design a daylighting system for their model houses based on their observations and calculations of the optimal use of available sunlight to their structure.

  1. History and Systems of Psychology: A Course to Unite a Core Curriculum

    ERIC Educational Resources Information Center

    Williams, Joshua L.; McCarley, Nancy; Kraft, John

    2013-01-01

    Core curricula are designed, in part, to help undergraduate students become intellectually well-rounded. To merge core curricula with the components of the scholarship of teaching and learning movement, students engaged in core curricula need capstone courses designed to aid them in retaining information over the long term and synthesizing…

  2. Scoring Dawg Core Breakoff and Retention Mechanism

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Backes, Paul G.

    2011-01-01

    This novel core break-off and retention mechanism consists of a scoring dawg controlled by a set of two tubes (a drill tube and an inner tube). The drill tube and the inner tube have longitudinal concentric holes. The solution can be implemented in an eccentric tube configuration as well where the tubes have eccentric longitudinal holes. The inner tube presents at the bottom two control surfaces for controlling the orientation of the scoring dawg. The drill tube presents a sunk-in profile on the inside of the wall for housing the scoring dawg. The inner tube rotation relative to the drill tube actively controls the orientation of the scoring dawg and hence its penetration and retrieval from the core. The scoring dawg presents a shaft, two axially spaced arms, and a tooth. The two arms slide on the control surfaces of the inner tube. The tooth, when rotated, can penetrate or be extracted from the core. During drilling, the two tubes move together maintaining the scoring dawg completely outside the core. After the desired drilling depth has been reached the inner tube is rotated relative to the drill tube such that the tooth of the scoring dawg moves toward the central axis. By rotating the drill tube, the scoring dawg can score the core and so reduce its cross sectional area. The scoring dawg can also act as a stress concentrator for breaking the core in torsion or tension. After breaking the core, the scoring dawg can act as a core retention mechanism. For scoring, it requires the core to be attached to the rock. If the core is broken, the dawg can be used as a retention mechanism. The scoring dawg requires a hard-tip insert like tungsten carbide for scoring hard rocks. The relative rotation of the two tubes can be controlled manually or by an additional actuator. In the implemented design solution the bit rotation for scoring was in the same direction as the drilling. The device was tested for limestone cores and basalt cores. The torque required for breaking the 10-mm diameter limestone cores was 5 to 5.8 lb-in. (0.56 to 0.66 N-m).

  3. Test Requirements for Embedded Core-Based Systems and IEEE P1500

    Microsoft Academic Search

    Yervant Zorian

    1997-01-01

    Chips comprising reusable cores, i.e. pre-designed Intellectual Property (IP) blocks, have become an important part of IC-based system design. Using embedded cores enables the design of high-complexity system-chips with densities as high as millions of gates on a single die. The increase in using pre-designed IP cores in system-chips adds to the complexity of test. To test system-chips adequately, test

  4. Core assembly storage structure

    DOEpatents

    Jones, Jr., Charles E. (Northridge, CA); Brunings, Jay E. (Chatsworth, CA)

    1988-01-01

    A structure for the storage of core assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the core assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot core assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the core assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.

  5. Biospecimen Core Resource

    Cancer.gov

    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.

  6. INTEGRAL core programme

    NASA Technical Reports Server (NTRS)

    Gehrels, N.; Schoenfelder, V.; Ubertini, P.; Winkler, C.

    1997-01-01

    The International Gamma Ray Astrophysics Laboratory (INTEGRAL) mission is described with emphasis on the INTEGRAL core program. The progress made in the planning activities for the core program is reported on. The INTEGRAL mission has a nominal lifetime of two years with a five year extension option. The observing time will be divided between the core program (between 30 and 35 percent during the first two years) and general observations. The core program consists of three main elements: the deep survey of the Galactic plane in the central radian of the Galaxy; frequent scans of the Galactic plane in the search for transient sources, and pointed observations of several selected sources. The allocation of the observation time is detailed and the sensitivities of the observations are outlined.

  7. INNOVATIVE TECHNOLOGY EVALUATION REPORT, SEDIMENT SAMPLING TECHNOLOGY, ART'S MANUFACTURING, SPLIT CORE SAMPLER FOR SUBMERGED SEDIMENTS

    EPA Science Inventory

    The Split Core Sampler for Submerged Sediments (Split Core Sampler) designed and fabricated by Arts Manufacturing & Supply, Inc., was demonstrated under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation Program in April and May 1999 at ...

  8. Chalcogenide glass hollow core photonic crystal fibers

    Microsoft Academic Search

    Frédéric Désévédavy; Gilles Renversez; Johann Troles; Patrick Houizot; Laurent Brilland; Ion Vasilief; Quentin Coulombier; Nicholas Traynor; Frédéric Smektala; Jean-Luc Adam

    2010-01-01

    We report the first hollow core photonic crystal fibers (HC PCF) in chalcogenide glass. To design the required HC PCF profiles for such high index glass, we use both band diagram analysis to define the required photonic bandgap and numerical simulations of finite size HC PCFs to compute the guiding losses. The material losses have also been taken into account

  9. Simplified hollow-core photonic crystal fiber

    Microsoft Academic Search

    Frederic Gerome; Raphaël Jamier; Jean-Louis Auguste; Georges Humbert; Jean-Marc Blondy

    2010-01-01

    A simplified design inspired from kagomé-lattice fiber reduced to one layer of air-holes was proposed demonstrating the anti-resonant core guiding capability. Two large low-loss windows were measured (minimum attenuation <0.2dB\\/m) with acceptable infrared bend losses.

  10. Testing Embedded-Core-Based System Chips

    Microsoft Academic Search

    Yervant Zorian; Erik Jan Marinissen; Sujit Dey

    1999-01-01

    Recently, designers have been embedding reusable modules to build on-chip systems that form rich libraries of predesigned, preverified building blocks. These embedded cores make it easier to import technology to a new system and differentiate the corresponding product by leveraging intellectual property advantages. Most importantly, design reuse shortens the time-to-market for new systems. The attributes that make system chips built

  11. Core bounce supernovae

    SciTech Connect

    Cooperstein, J.

    1987-01-01

    The gravitational collapse mechanism for Type II supernovae is considered, concentrating on the direct implosion - core bounce - hydrodynamic explosion picture. We examine the influence of the stiffness of the dense matter equation of state and discuss how the shock wave is formed. Its chances of success are determined by the equation of state, general relativistic effects, neutrino transport, and the size of presupernova iron core. 12 refs., 1 tab.

  12. Central core disease

    Microsoft Academic Search

    Heinz Jungbluth

    2007-01-01

    Central core disease (CCD) is an inherited neuromuscular disorder characterised by central cores on muscle biopsy and clinical\\u000a features of a congenital myopathy. Prevalence is unknown but the condition is probably more common than other congenital myopathies.\\u000a CCD typically presents in infancy with hypotonia and motor developmental delay and is characterized by predominantly proximal\\u000a weakness pronounced in the hip girdle;

  13. Emergency core cooling system

    DOEpatents

    Schenewerk, William E. (Sherman Oaks, CA); Glasgow, Lyle E. (Westlake Village, CA)

    1983-01-01

    A liquid metal cooled fast breeder reactor provided with an emergency core cooling system includes a reactor vessel which contains a reactor core comprising an array of fuel assemblies and a plurality of blanket assemblies. The reactor core is immersed in a pool of liquid metal coolant. The reactor also includes a primary coolant system comprising a pump and conduits for circulating liquid metal coolant to the reactor core and through the fuel and blanket assemblies of the core. A converging-diverging venturi nozzle with an intermediate throat section is provided in between the assemblies and the pump. The intermediate throat section of the nozzle is provided with at least one opening which is in fluid communication with the pool of liquid sodium. In normal operation, coolant flows from the pump through the nozzle to the assemblies with very little fluid flowing through the opening in the throat. However, when the pump is not running, residual heat in the core causes fluid from the pool to flow through the opening in the throat of the nozzle and outwardly through the nozzle to the assemblies, thus providing a means of removing decay heat.

  14. Industrial Technology Core (IT Core) Guide

    NSDL National Science Digital Library

    This resource, created by the South Carolina Advanced Technological Education (SC ATE) National Resource Center, introduces students to core projects of industrial technology. The lesson involves five different activities, the topics include: an introduction to technology careers, basic hand tools, mechanical advantage, basic electricity and hydraulic systems. A suggested equipment list, instructors notes, and objectives are included to guide instructors in preparing these lessons plans. Each one of these topics includes a worksheet for students to actively participate in these lessons. This is a comprehensive set of lessons to help students better understand the different elements in industrial technology.

  15. High-voltage air-core pulse transformers

    Microsoft Academic Search

    G. J. Rohwein

    1981-01-01

    Air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The general types

  16. Failure of sandwich beams with metallic foam cores

    Microsoft Academic Search

    T. M. McCormack; R. Miller; O. Kesler; L. J. Gibson

    2001-01-01

    Sandwich beams with metallic foam cores can fail by several modes: face yielding, face wrinkling, core yielding and indentation. We estimate the initial failure load, corresponding to the first deviation from linearity in the load–deflection curve as well as the peak load for each mode. Failure mode maps are constructed which illustrate the dominant failure mode for practical beam designs.

  17. Modeling the Arm II core in MicroCap IV

    Microsoft Academic Search

    Dalton

    1996-01-01

    This paper reports on how an electrical model for the core of the Arm II machine was created and how to use this model. We wanted to get a model for the electrical characteristics of the ARM II core, in order to simulate this machine and to assist in the design of a future machine. We wanted this model to

  18. Getting to the Core: Climate Change Over Time Lesson Plan

    NSDL National Science Digital Library

    Environmental Protection Agency

    "Getting to the Core: Climate Change Over Time" is designed to teach middle-school students to analyze the link between atmospheric temperatures and carbon dioxide (CO2) concentrations by looking at ice core data spanning hundreds of thousands of years. It is a lesson plan created for the Environmental Protection Agency's Student's Guide to Global Climate Change.

  19. A dynamic model for helium core heat exchangers

    Microsoft Academic Search

    W. E. Schiesser; H. J. Shih; D. G. Hartozog; D. M. Herron; D. Nahmias; W. G. Stuber; A. C. Hindmarsh

    1990-01-01

    To meet the helium (He) requirements of the superconducting supercollider (SSC), the cryogenic plants must be able to respond to time-varying loads. Thus the design and simulation of the cryogenic plants requires dynamic models of their principal components, and in particular, the core heat exchangers. In this paper, we detail the derivation and computer implementation of a model for core

  20. Identifying test methods for breeder reactor core materials

    SciTech Connect

    Not Available

    1981-01-01

    The practice covers the test methods that may be used for measuring physical and mechanical properties for solid metallic materials for use in the design and evaluation of fast breeder reactor core materials. The test methods referenced are applicable to the in-core portion of ducts, cladding (both end caps and tubing), wire wrap, spacer grids, wear pads, and welded structures. (JMT)

  1. RIKEN Quantitative Biology Center Cell Dynamics Research Core

    E-print Network

    Fukai, Tomoki

    RIKEN Quantitative Biology Center Cell Dynamics Research Core Laboratory for Cell Dynamics Design Research Core Laboratory for Synthetic Biology Laboratory for Cell-Free Protein Synthesis Observation Laboratory for Single Cell Gene Dynamics Laboratory for Cell Field Structure Laboratory for Cell

  2. RIKEN Quantitative Biology Center Cell Dynamics Research Core

    E-print Network

    Fukai, Tomoki

    RIKEN Quantitative Biology Center Cell Dynamics Research Core Laboratory for Cell Dynamics for Developmental Morphogeometry Cell Design Research Core Laboratory for Synthetic Biology Laboratory for Cell Observation Laboratory for Single Cell Gene Dynamics Laboratory for Cell Field Structure Laboratory for Cell

  3. Formed Core Sampler Hydraulic Conductivity Testing

    SciTech Connect

    Miller, D. H.; Reigel, M. M.

    2012-09-25

    A full-scale formed core sampler was designed and functionally tested for use in the Saltstone Disposal Facility (SDF). Savannah River National Laboratory (SRNL) was requested to compare properties of the formed core samples and core drilled samples taken from adjacent areas in the full-scale sampler. While several physical properties were evaluated, the primary property of interest was hydraulic conductivity. Differences in hydraulic conductivity between the samples from the formed core sampler and those representing the bulk material were noted with respect to the initial handling and storage of the samples. Due to testing conditions, the site port samples were exposed to uncontrolled temperature and humidity conditions prior to testing whereas the formed core samples were kept in sealed containers with minimal exposure to an uncontrolled environment prior to testing. Based on the results of the testing, no significant differences in porosity or density were found between the formed core samples and those representing the bulk material in the test stand.

  4. Flux harmonics in large SFR cores in relation with core characteristics such as power peaks

    SciTech Connect

    Rimpault, G.; Buiron, L.; Fontaine, B.; Sciora, P.; Tommasi, J. [CEA, DEN, DER, SPRC Cadarache, F-13108 Saint Paul-lez-Durance (France)

    2013-07-01

    Designing future Sodium Fast Reactors (SFR) requires enhancing their operational performance and reducing the probability to go into core disruption. As a consequence of these constraints, these novel reactors exhibit rather unusual features compared to past designs. The cores are much larger with rather flat shape. The consequences of that shape on the core characteristics deserve to be studied. The approach taken in this paper is to calculate the eigenvalue associated to the first harmonic and its associated flux. It is demonstrated that these values are linked to some core features, in particular, those sensitive to spatial effects such as power peaks induced by the movement of control rods. The uncertainty associated to these characteristics is being tentatively studied and guidelines for further studied are being identified. In the development strategy of these new SFR designs, a first demonstration plant of limited installed power (around 1500 MWth) will have to be built first. Identifying the possibility of going later to higher power plants (around 3600 MWth) without facing new challenges is an important criterion for designing such a plant. That strategy is being studied, in this paper, focusing on some rather frequent initiator such as the inadvertent control rod withdrawal for different core sizes with the help of the perturbation theory and the flux harmonics. (authors)

  5. All-University Core Curriculum All-University Core Curriculum

    E-print Network

    Collett Jr., Jeffrey L.

    /gtPathways/curri culum.html _______________ 2.3 Page 1 #12;All-University Core Curriculum B. Mathematics.1 The objectiveAll-University Core Curriculum All-University Core Curriculum Office of Vice Provost-UNIVERSITY CORE CURRICULUM (AUCC) All Colorado State University students share a learning experience in common

  6. All-University Core Curriculum All-University Core Curriculum

    E-print Network

    All-University Core Curriculum _______________ 2.3 Page 1 All-University Core Curriculum Office of Vice Provost for Undergraduate Affairs Administration Building, Room 108 core.colostate.edu ALL-UNIVERSITY CORE CURRICULUM (AUCC) All Colorado State University students share a learning experience in common

  7. Pressure Core Characterization

    NASA Astrophysics Data System (ADS)

    Santamarina, J. C.

    2014-12-01

    Natural gas hydrates form under high fluid pressure and low temperature, and are found in permafrost, deep lakes or ocean sediments. Hydrate dissociation by depressurization and/or heating is accompanied by a multifold hydrate volume expansion and host sediments with low permeability experience massive destructuration. Proper characterization requires coring, recovery, manipulation and testing under P-T conditions within the stability field. Pressure core technology allows for the reliable characterization of hydrate bearing sediments within the stability field in order to address scientific and engineering needs, including the measurement of parameters used in hydro-thermo-mechanical analyses, and the monitoring of hydrate dissociation under controlled pressure, temperature, effective stress and chemical conditions. Inherent sampling effects remain and need to be addressed in test protocols and data interpretation. Pressure core technology has been deployed to study hydrate bearing sediments at several locations around the world. In addition to pressure core testing, a comprehensive characterization program should include sediment analysis, testing of reconstituted specimens (with and without synthetic hydrate), and in situ testing. Pressure core characterization technology can be used to study other gas-charged formations such as deep sea sediments, coal bed methane and gas shales.

  8. 17 CFR 38.800 - Core Principle 15.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...TRADING COMMISSION DESIGNATED CONTRACT MARKETS Governance Fitness Standards § 38.800 Core Principle 15. The board of trade shall establish and enforce appropriate fitness standards for directors, members of any disciplinary...

  9. 17 CFR 38.800 - Core Principle 15.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...TRADING COMMISSION DESIGNATED CONTRACT MARKETS Governance Fitness Standards § 38.800 Core Principle 15. The board of trade shall establish and enforce appropriate fitness standards for directors, members of any disciplinary...

  10. Photonic mircocells based on hollow-core PCF

    Microsoft Academic Search

    Fetah Benabid

    2011-01-01

    We review the recent progress on hollow-core photonic crystal fibers and its integrated form of photonic microcells in both their design and fabrication and in their applications for coherent optics, Raman comb generation and laser metrology.

  11. Journals in the Core Collection

    Microsoft Academic Search

    Thomas E. Nisonger

    2007-01-01

    This overview of the core concept applied to journals defines the relevant terminology and cites specific examples of core lists. Ten approaches for determining core journals (subjective judgment, use, indexing coverage, overlapping library holdings, citation data, citation network\\/co-citation analysis, production of articles, Bradford's Law, faculty publication data, and multiple criteria methods) are reviewed and the practical applications of core journals

  12. ROPEC - ROtary PErcussive Coring Drill for Mars Sample Return

    NASA Technical Reports Server (NTRS)

    Chu, Philip; Spring, Justin; Zacny, Kris

    2014-01-01

    The ROtary Percussive Coring Drill is a light weight, flight-like, five-actuator drilling system prototype designed to acquire core material from rock targets for the purposes of Mars Sample Return. In addition to producing rock cores for sample caching, the ROPEC drill can be integrated with a number of end effectors to perform functions such as rock surface abrasion, dust and debris removal, powder and regolith acquisition, and viewing of potential cores prior to caching. The ROPEC drill and its suite of end effectors have been demonstrated with a five degree of freedom Robotic Arm mounted to a mobility system with a prototype sample cache and bit storage station.

  13. USGS National Ice Core Laboratory

    NSDL National Science Digital Library

    This United States Geological Survey site highlights the work of the National Ice Core Laboratory (NICL). It discusses the NICL's role, why ice cores are important to study, how ice cores are drilled and studied, and core drilling locations. These cores are recovered and studied for a variety of scientific investigations, most of which focus on the reconstruction of Earth's climate history. The facility currently houses over 14,000 meters of ice cores from 34 drill sites in Greenland, Antarctica, and high mountain glaciers in the Western United States. There are links for more information and individual core information such as numbers, locations and sizes.

  14. Arts at the Core

    NSDL National Science Digital Library

    The Arts at the Core Initiative is part of The College Board's Advocacy & Policy Center, created "to help transform education in America." Part of the Center's work involves the Arts at the Core project, whose goal is "to empower education leaders, particularly in under-resourced districts, to implement rigorous arts programming in their schools." Under the Our Progress section, visitors learn about some of the resources created to achieve this goal. Moving on, the News & Events area contains links to recent success stories of bringing arts education programs to schools, along with updates from the field of research into this area. Visitors shouldn't miss the Publications area, which contains a brochure about flagship programs and a summary of key recommendations for school systems seeking to move arts to the core of their mission.

  15. College of Visual Arts and Design B.F.A. Fashion Design

    E-print Network

    Mohanty, Saraju P.

    College of Visual Arts and Design B.F.A. Fashion Design 2012-2013 Texas Common Course Numbering concurrent enrollment options. Fashion Design: Core Course Requirements ARTS 1301 (fulfills Discovery core not include all courses required for the UNT Fashion Design major. Fashion Design: Other Course Requirements

  16. Global Ice Core Research

    NSDL National Science Digital Library

    This informative site from the US Geological Survey (USGS) covers the latest ice-core research projects from around the world, including sites in Nepal, Norway, and Kyrghyzstan. Authored by researchers at the Global Ice core Research Office, the site contains an overview of the mid-latitude and polar glaciers, isotopic methods in glacial research, and applications to paleoclimatology. Links to maps, figures, and in some cases, full-text articles (HTML) about specific glaciers are available, and the site is peppered with color photos of glacial environments. Links to biographies of the scientists involved in the project, contacts, and other snow and ice sites are also listed.

  17. Approaches for achieving very high core outlet temperatures in prismatic modular helium reactors

    SciTech Connect

    LaBar, M.; Richards, M.; Shenoy, A. [General Atomics, 3550 General Atomics Court, San Diego, CA 92121-1122 (United States)

    2004-07-01

    High Temperature Gas Reactors (HTGRs) cooled by helium have the capability to develop high core outlet temperatures. The upper temperature bound of HTGRs designed and operated to-date is approximately 950 deg. C. But, the goal for the Next Generation Nuclear Plant (NGNP) is a mixed mean core outlet temperature of 1000 deg. C. The most limiting core design criteria governing core outlet temperature in HTGRs is diffusive fission product release from the fuel. For the reference TRISO coated particle fuel used by HTGRs, the rule of thumb for maintaining fission product releases low enough to meet regulatory limits, is a maximum peak fuel temperature for normal operation of about 1250 deg. C. The Gas-Turbine Modular Helium Reactor (GT-MHR), which employs a prismatic core design, has a design mixed mean core outlet temperature of 850 deg. C. Initial evaluations have been made for a core of the type employed by the GT-MHR to determine the feasibility of increasing the core outlet temperature to 1000 deg. C. The conclusion has been reached that design approaches are available for making the 1000 deg. C temperature potentially achievable, while still meeting peak fuel temperature limits albeit with reduced design margin. These potential design approaches and their effects for achieving a 1000 deg. C core outlet temperature in a prismatic core design are described. (authors)

  18. Implementation of AHB interface in a communication-specific CPU based on ARM core

    Microsoft Academic Search

    Xianyang Jiang; Hu Chen; Xubang Shen; Tianxu Zhang

    2001-01-01

    The characteristics of design of embedded CPU based on IP core are analyzed, then provides the design hole problems existing in design of AHB interface in an ARM core based CPU .By modification on AHB protocol, hole-avoiding methods are presented. In the end, hardware implementation of AHB interface is discussed.

  19. A two-stage collapsible core for injection moulded plastic parts with internal undercuts

    Microsoft Academic Search

    S. B Tor; S. G Lee; S. H Chung Yee Hian

    2000-01-01

    The internal grooved (undercut) features of plastic injection moulded parts are formed by collapsible cores. While collapsible cores have been designed for pipe sizes smaller than 90 mm in diameter, those for larger pipes are custom designed. The objective of this research was to fully automate the design procedure which, for uPVC pipe fittings is laborious and error-prone at present.

  20. Research on plasma core reactors

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    Experiments and theoretical studies are being conducted for NASA on critical assemblies with one-meter diameter by one-meter 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 diameter 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 UF6 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 cu cm aluminum canister in the central region was fueled with UF6 gas and fission density distributions determined. These results are to be used to guide the design of a prototype plasma core reactor which will test energy removal by optical radiation.

  1. The core legion object model

    SciTech Connect

    Lewis, M.; Grimshaw, A. [Univ. of Virginia, Charlottesville, VA (United States)

    1996-12-31

    The Legion project at the University of Virginia is an architecture for designing and building system services that provide the illusion of a single virtual machine to users, a virtual machine that provides secure shared object and shared name spaces, application adjustable fault-tolerance, improved response time, and greater throughput. Legion targets wide area assemblies of workstations, supercomputers, and parallel supercomputers, Legion tackles problems not solved by existing workstation based parallel processing tools; the system will enable fault-tolerance, wide area parallel processing, inter-operability, heterogeneity, a single global name space, protection, security, efficient scheduling, and comprehensive resource management. This paper describes the core Legion object model, which specifies the composition and functionality of Legion`s core objects-those objects that cooperate to create, locate, manage, and remove objects in the Legion system. The object model facilitates a flexible extensible implementation, provides a single global name space, grants site autonomy to participating organizations, and scales to millions of sites and trillions of objects.

  2. Reactor design for nuclear electric propulsion

    NASA Technical Reports Server (NTRS)

    Koenig, D. R.; Ranken, W. A.

    1979-01-01

    The paper analyzes the consequences of heat pipe failures, that resulted in modifications to the basic design of a heat-pipe cooled, fast spectrum nuclear reactor and led to consideration of an entirely different core design. The new design features an integral laminated core configuration consisting of alternating layers of UO2 and molybdenum sheets that span the diameter of the core. Design characteristics are presented and compared for two reactors. A conceptual design for a heat exchanger between the core and the thermionic converter assembly is described. This heat exchanger would provide design and fabrication decoupling of these two assemblies.

  3. Experimental Evaluation of Integrity of FBR Core under Seismic Events

    NASA Astrophysics Data System (ADS)

    Chellapandi, Perumal; Rajan Babu, Vinayagamoorthy; Puthiyavinayagam, Pillai; Chetal, Subhash Chander; Raj, Baldev

    The core of Prototype Fast Breeder Reactor (PFBR) is designed to produce 1250 MWt at full power. PFBR is under construction at Kalpakkam, India. In PFBR, the core is of free standing type and one of the major safety criteria for the design of core subassemblies is that the integrity of the core subassemblies should not be impaired and they should not be lifted up from the grid plate even during seismic condition. The net downward force acting on the grid plate is less than the weight of the subassembly due to the hydraulic lifting forces acting on it. Experimental analysis has been carried out to ensure that the subassembly does not get lifted off due to vertical seismic excitation. This paper gives the details of the methodology adopted for the experimental seismic analysis carried out on a core subassembly and the upward displacement of the subassembly under the combined effect of upward fluid force and vertical seismic excitations.

  4. Low core loss rotating flux transformer

    NASA Astrophysics Data System (ADS)

    Krause, R. F.; Del Vecchio, R. M.

    1988-11-01

    A rotating magnetic induction at saturation generates no hysteresis losses. In addition, because domain walls are absent, there are no anomalous eddy current losses. Thus, only classical eddy current losses are present. In materials with high resistivity such as ferrites or materials fabricated into thin sheets such as amorphous metals, these classical losses are small. A transformer has been designed which utilizes this principle. It consists of a hollow toroidal core with toroidal windings wrapped outside the core and poloidal windings wrapped through the interior channel. When these windings are energized by currents 90 electrical degrees apart or, with suitable winding schemes, by three-phase currents, rotating flux is generated throughout the core volume.

  5. Data management integration for biomedical core facilities

    NASA Astrophysics Data System (ADS)

    Zhang, Guo-Qiang; Szymanski, Jacek; Wilson, David

    2007-03-01

    We present the design, development, and pilot-deployment experiences of MIMI, a web-based, Multi-modality Multi-Resource Information Integration environment for biomedical core facilities. This is an easily customizable, web-based software tool that integrates scientific and administrative support for a biomedical core facility involving a common set of entities: researchers; projects; equipments and devices; support staff; services; samples and materials; experimental workflow; large and complex data. With this software, one can: register users; manage projects; schedule resources; bill services; perform site-wide search; archive, back-up, and share data. With its customizable, expandable, and scalable characteristics, MIMI not only provides a cost-effective solution to the overarching data management problem of biomedical core facilities unavailable in the market place, but also lays a foundation for data federation to facilitate and support discovery-driven research.

  6. Modelling of crack deflection at core junctions in sandwich structures

    NASA Astrophysics Data System (ADS)

    Jakobsen, J.; Andreasen, J. H.; Thomsen, O. T.

    2009-08-01

    The paper treats the problem of crack propagation in sandwich panels with interior core junctions. When a face-core interface crack approaches a trimaterial wedge, as it may occur at a sandwich core junction, two options exist for further crack advance; one is for the interface crack to penetrate the wedge along the face-core interface, and the second is deflection along the core junction interface. Crack deflection is highly relevant and a requirement for the functionality of a newly developed peel stopper for sandwich structures. The physical model presented in this paper enables the quantitative prediction of the ratio of the toughnesses of the two wedge interfaces required to control the crack propagation, and the derived results can be applied directly in future designs of sandwich structures. The solution strategy is based on finite element analysis (FEA), and a realistic engineering practice example of a tri-material composition corresponding to face and core materials is presented.

  7. MetaCore: an application-specific programmable DSP development system

    Microsoft Academic Search

    Jin-hyuk Yang; Byoung-woon Kim; Sang-joon Nam; Young-su Kwon; Dae-hyun Lee; Jong-yeol Lee; Chan-soo Hwang; Yong-hoon Lee; Seung-Ho Hwang; In-cheol Park; Chong-min Kyung

    2000-01-01

    This paper describes the MetaCore system which is an application-specific instruction-set processor (ASIP) develop- ment system targeted for digital signal processor (DSP) applica- tions. The goal of the MetaCore system is to offer an efficient design methodology meeting specifications given as a combination of per- formance, cost, and design turnaround time. The MetaCore system consists of two major design stages:

  8. Art & Design DAVID CRONRATH

    E-print Network

    Harms, Kyle E.

    COLLEGE OF Art & Design DAVID CRONRATH Dean C. BARRETT KENNEDY Associate Dean for Graduate Programs of Art and Design is a community of engaged students and faculty committed to speculative endeavors in all aspects of the visual arts and design disciplines. The College community's core is fundamental

  9. Optimization of nanoparticle core size for magnetic particle imaging

    SciTech Connect

    Ferguson, Matthew R.; Minard, Kevin R.; Krishnan, Kannan M.

    2009-05-01

    Magnetic Particle Imaging (MPI) is a powerful new diagnostic visualization platform designed for measuring the amount and location of superparamagnetic nanoscale molecular probes (NMPs) in biological tissues. Promising initial results indicate that MPI can be extremely sensitive and fast, with good spatial resolution for imaging human patients or live animals. Here, we present modeling results that show how MPI sensitivity and spatial resolution both depend on NMP-core physical properties, and how MPI performance can be effectively optimized through rational core design. Monodisperse magnetite cores are attractive since they are readily produced with a biocompatible coating and controllable size that facilitates quantitative imaging.

  10. PRISMATIC CORE COUPLED TRANSIENT BENCHMARK

    SciTech Connect

    J. Ortensi; M.A. Pope; G. Strydom; R.S. Sen; M.D. DeHart; H.D. Gougar; C. Ellis; A. Baxter; V. Seker; T.J. Downar; K. Vierow; K. Ivanov

    2011-06-01

    The Prismatic Modular Reactor (PMR) is one of the High Temperature Reactor (HTR) design concepts that have existed for some time. Several prismatic units have operated in the world (DRAGON, Fort St. Vrain, Peach Bottom) and one unit is still in operation (HTTR). The deterministic neutronics and thermal-fluids transient analysis tools and methods currently available for the design and analysis of PMRs have lagged behind the state of the art compared to LWR reactor technologies. This has motivated the development of more accurate and efficient tools for the design and safety evaluations of the PMR. In addition to the work invested in new methods, it is essential to develop appropriate benchmarks to verify and validate the new methods in computer codes. The purpose of this benchmark is to establish a well-defined problem, based on a common given set of data, to compare methods and tools in core simulation and thermal hydraulics analysis with a specific focus on transient events. The benchmark-working group is currently seeking OECD/NEA sponsorship. This benchmark is being pursued and is heavily based on the success of the PBMR-400 exercise.

  11. Shuttle Spacelab Core Equipment Freezer

    NASA Technical Reports Server (NTRS)

    Copeland, R. J.

    1977-01-01

    This paper describes the preliminary design of a Shuttle Spacelab Core Equipment Freezer. The unit will provide the capability to freeze and store many experiment specimens. Two models of the unit are planned. One model provides storage at -70 C; the other model will provide -70 C storage, a freeze dry capability, storage at a selectable temperature in the range of 0 C to -70 C, and means of maintaining close temperature tolerances. In addition an exchanger loop will be available at 4 C for cooling of a centrifuge and a remote storage compartment. A test tube holder, a dish holder and thermal capacitors for rapid freezing of large specimens will also be provided. A Stirling Cycle was selected as the active refrigerator for minimum cost and weight.

  12. Electromagnetic pump stator core

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Olich, Eugene E. (Aptos, CA); Dahl, Leslie R. (Livermore, CA)

    1995-01-01

    A stator core for supporting an electrical coil includes a plurality of groups of circumferentially abutting flat laminations which collectively form a bore and perimeter. A plurality of wedges are interposed between the groups, with each wedge having an inner edge and a thicker outer edge. The wedge outer edges abut adjacent ones of the groups to provide a continuous path around the perimeter.

  13. Utah's New Mathematics Core

    ERIC Educational Resources Information Center

    Utah State Office of Education, 2011

    2011-01-01

    Utah has adopted more rigorous mathematics standards known as the Utah Mathematics Core Standards. They are the foundation of the mathematics curriculum for the State of Utah. The standards include the skills and understanding students need to succeed in college and careers. They include rigorous content and application of knowledge and reflect…

  14. Ultrasonic Drilling and Coring

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    1998-01-01

    A novel drilling and coring device, driven by a combination, of sonic and ultrasonic vibration, was developed. The device is applicable to soft and hard objects using low axial load and potentially operational under extreme conditions. The device has numerous potential planetary applications. Significant potential for commercialization in construction, demining, drilling and medical technologies.

  15. Soil Core Sample #2

    USGS Multimedia Gallery

    Soil core obtained from existing goose grazing lawn along the Smith River in the Teshekpuk Lake Special Area of the National Petroleum Reserve - Alaska.  Buried peat layer broken open.  Closer examination of the buried peat layer demonstrates that non-salt-tolerant vegetation from the past...

  16. Soil Core Sample #1

    USGS Multimedia Gallery

    Soil core obtained from existing goose grazing lawn along the Smith River in the Teshekpuk Lake Special Area of the National Petroleum Reserve - Alaska.  The buried layer of peat beneath goose grazing lawn demonstrates that vegetation change has occurred in this area....

  17. From Context to Core

    ERIC Educational Resources Information Center

    Campus Technology, 2008

    2008-01-01

    At Campus Technology 2008, Arizona State University Technology Officer Adrian Sannier mesmerized audiences with his mandate to become more efficient by doing only the "core" tech stuff--and getting someone else to slog through the context. This article presents an excerpt from Sannier's hour-long keynote address at Campus Technology '08. Sannier…

  18. Resolving Supercritical Orion Cores

    NASA Astrophysics Data System (ADS)

    Li, Di; Chapman, N.; Goldsmith, P.; Velusamy, T.

    2009-01-01

    The theoretical framework for high mass star formation (HMSF) is unclear. Observations reveal a seeming dichotomy between high- and low-mass star formation, with HMSF occurring only in Giant Molecular Clouds (GMC), mostly in clusters, and with higher star formation efficiencies than low-mass star formation. One crucial constraint to any theoretical model is the dynamical state of massive cores, in particular, whether a massive core is in supercritical collapse. Based on the mass-size relation of dust emission, we select likely unstable targets from a sample of massive cores (Li et al. 2007 ApJ 655, 351) in the nearest GMC, Orion. We have obtained N2H+ (1-0) maps using CARMA with resolution ( 2.5", 0.006 pc) significantly better than existing observations. We present observational and modeling results for ORI22. By revealing the dynamic structure down to Jeans scale, CARMA data confirms the dominance of gravity over turbulence in this cores. This work was performed by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  19. Deep Sea Coring

    NSDL National Science Digital Library

    Woods Hole Oceanographic Institution; Ocean and Climate Change Institute

    This Ocean and Climate Change Institute module features a brief, but image-rich overview of ocean drilling and sediment analysis to determine paleoclimate (past climate). This site is the first of a 3-page module, the other two sites (Describing the Core; Sampling Techniques) are linked at the top of the article.

  20. Navagating the Common Core

    ERIC Educational Resources Information Center

    McShane, Michael Q.

    2014-01-01

    This article presents a debate over the Common Core State Standards Initiative as it has rocketed to the forefront of education policy discussions around the country. The author contends that there is value in having clear cross state standards that will clarify the new online and blended learning that the growing use of technology has provided…

  1. Renewing the Core Curriculum

    ERIC Educational Resources Information Center

    Lawson, Hal A.

    2007-01-01

    The core curriculum accompanied the development of the academic discipline with multiple names such as Kinesiology, Exercise and Sport Science, and Health and Human Performance. It provides commonalties for undergraduate majors. It is timely to renew this curriculum. Renewal involves strategic reappraisals. It may stimulate change or reaffirm the…

  2. Internal core tightener. [LMFBR

    Microsoft Academic Search

    G. V. Brynsvold; H. J. Jr. Snyder

    1976-01-01

    An internal core tightener is disclosed which is a linear actuated (vertical actuation motion) expanding device utilizing a minimum of moving parts to perform the lateral tightening function. The key features are: (1) large contact areas to transmit loads during reactor operation; (2) actuation cam surfaces loaded only during clamping and unclamping operation; (3) separation of the parts and internal

  3. Internal core tightener

    Microsoft Academic Search

    Glen V. Brynsvold; Snyder Jr. Harold J

    1976-01-01

    An internal core tightener which is a linear actuated (vertical actuation motion) expanding device utilizing a minimum of moving parts to perform the lateral tightening function. The key features are: (1) large contact areas to transmit loads during reactor operation; (2) actuation cam surfaces loaded only during clamping and unclamping operation; (3) separation of the parts and internal operation involved

  4. Core competence (knowledge) (skill)

    E-print Network

    Wu, Yih-Min

    Core competence 8 5~8 2 3 4 5 6 7 8 PPS003 Ver. 1.1 2011/03/07 #12; 2 (knowledge) (skill) (attitude) Set of skill, knowledge or attitude which should be learned or acquired by each, 2000) (knowledge) (skill) (attitude) Set of skill, knowledge or attitude which should be learned

  5. Diagnostics of core barrel vibrations by in-core and ex-core neutron noise

    Microsoft Academic Search

    V. Arzhanov; I. Pázsit

    2003-01-01

    Diagnostics of core-barrel vibrations has traditionally been made by use of ex-vessel neutron detector signals. We suggest that in addition to the ex-core noise, also the in-core noise, induced by core barrel vibrations, be also used. This would enhance the possibilities of diagnostics where the number of the ex-core detectors is not sufficient or their positions are disadvantageous for effective

  6. Coring Methane Hydrate by using Hybrid Pressure Coring System of D/V Chikyu

    NASA Astrophysics Data System (ADS)

    Kubo, Y.; Mizuguchi, Y.; Inagaki, F.; Eguchi, N.; Yamamoto, K.

    2013-12-01

    Pressure coring is a technique to keep in-situ conditions in recovering sub-seafloor sediment samples, which are potentially rich in soluble or hydrated gas. In regular core sampling, gas fractions are easily lost through the changes in the pressure and temperature during core recovery, and it has significant impact on the chemical components of the sample. Rapid degassing may also cause critical damages of original structures. To study original characteristics of gaseous sub-seafloor sediment, a new Hybrid Pressure Coring System (Hybrid PCS) was developed for the D/V Chikyu operation by adapting some of the existing pressure sampling technologies. Hybrid PCS is composed of three main parts: top section for the wireline operation, middle section for the accumulator and pressure controlling system, and the bottom section for the autoclave chamber. The design concept is based on that of Pressure Core Sampler used in Ocean Drilling Program, and of Pressure Temperature Core Sampler (PTCS) and Non-cooled PTCS of Japan Oil, Gas and Metals National Corporation (JOGMEC). Several modifications were made including that on the ball valve, which operates to close the autoclave after coring. The core samples are 51 mm in diameter and up to 3.5 m in length. The system is combined with the Extented Shoe Coring System on the Chikyu and best suited for coring of semi-consolidated formation up to about 3400 m from the sea level. Sample autoclave is compatible with Pressure Core Analysis and Transfer System (PCATS) of Geotek Ltd for sub-sampling and analysis under in-situ pressure. The analysis in PCATS includes X-ray CT scan and core logging with P-wave velocity and gamma density. Depressurization provides accurate volume of gas and its sub-sampling. Hybrid PCS was first tested during the Chikyu Exp. 906 at a submarine mud-volcano in the Nankai Trough. A 0.9 m of hydrate rich material was recovered from the summit (water depth: 2000 m) and the intact hydrate structure was observed by X-ray CT scan. Hybrid PCS was also used in the following JOGMEC methane hydrate cruise, resulting in the good recovery of methane hydrate-bearing cores (approx. 69%).

  7. WEBEXPIR: Windowless target electron beam experimental irradiation

    NASA Astrophysics Data System (ADS)

    Dierckx, Marc; Schuurmans, Paul; Heyse, Jan; Rosseel, Kris; Van Tichelen, Katrien; Nactergal, Benoit; Vandeplassche, Dirk; Aoust, Thierry; Abs, Michel; Guertin, Arnaud; Buhour, Jean-Michel; Cadiou, Arnaud; Abderrahim, Hamid Aït

    2008-06-01

    The windowless target electron beam experimental irradiation (WEBEXPIR) program was set-up as part of the MYRRHA/XT-ADS R&D effort on the spallation target design to investigate the interaction of a proton beam with a liquid lead-bismuth eutectic (LBE) free surface. In particular, possible free surface distortion or shockwave effects in nominal conditions and during sudden beam on/off transient situations, as well as possible enhanced evaporation were assessed. An experiment was conceived at the IBA TT-1000 Rhodotron, where a 7 MeV electron beam was used to simulate the high power deposition at the MYRRHA/XT-ADS LBE free surface. The geometry and the LBE flow characteristics in the WEBEXPIR set-up were made as representative as possible of the actual situation in the MYRRHA/XT-ADS spallation target. Irradiation experiments were carried out at beam currents of up to 10 mA, corresponding to 40 times the nominal beam current necessary to reproduce the MYRRHA/XT-ADS conditions. Preliminary analyses show that the WEBEXPIR free surface flow was not disturbed by the interaction with the electron beam and that vacuum conditions stayed well within the design specifications.

  8. Application of Core Dynamics Modeling to Core-Mantle Interactions

    NASA Technical Reports Server (NTRS)

    Kuang, Weijia

    2003-01-01

    Observations have demonstrated that length of day (LOD) variation on decadal time scales results from exchange of axial angular momentum between the solid mantle and the core. There are in general four core-mantle interaction mechanisms that couple the core and the mantle. Of which, three have been suggested likely the dominant coupling mechanism for the decadal core-mantle angular momentum exchange, namely, gravitational core-mantle coupling arising from density anomalies in the mantle and in the core (including the inner core), the electromagnetic coupling arising from Lorentz force in the electrically conducting lower mantle (e.g. D-layer), and the topographic coupling arising from non-hydrostatic pressure acting on the core-mantle boundary (CMB) topography. In the past decades, most effort has been on estimating the coupling torques from surface geomagnetic observations (kinematic approach), which has provided insights on the core dynamical processes. In the meantime, it also creates questions and concerns on approximations in the studies that may invalidate the corresponding conclusions. The most serious problem is perhaps the approximations that are inconsistent with dynamical processes in the core, such as inconsistencies between the core surface flow beneath the CMB and the CMB topography, and that between the D-layer electric conductivity and the approximations on toroidal field at the CMB. These inconsistencies can only be addressed with numerical core dynamics modeling. In the past few years, we applied our MoSST (Modular, Scalable, Self-consistent and Three-dimensional) core dynamics model to study core-mantle interactions together with geodynamo simulation, aiming at assessing the effect of the dynamical inconsistencies in the kinematic studies on core-mantle coupling torques. We focus on topographic and electromagnetic core-mantle couplings and find that, for the topographic coupling, the consistency between the core flow and the CMB topography is critical for correct evaluation of the coupling torque.

  9. High-voltage air-core pulse transformers

    NASA Astrophysics Data System (ADS)

    Rohwein, G. J.

    1981-05-01

    General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited applications outside the normal ranges of conventional magnetic core transfers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources.

  10. Calculation methods for core distortions and mechanical behavior

    SciTech Connect

    Sutherland, W.H.

    1984-09-01

    This paper describes ABADAN, a general purpose, nonlinear, multi-dimensional finite element structural analyses computer code developed for the express purpose of solving large nonlinear problems as typified by the Liquid Metal Fast Breeder Reactor (LMFBR) Core Restraint System design problem. All of the structural modeling features inherent in a general purpose finite element code and required to adequately model an LMFBR core restraint system are demonstrated. Typical results for a radial row and a sixty degree sector model of FFTF are presented. The sixty degree sector results are interpreted in terms of the design criteria that the core restraint system must satisfy. Extensions and adaptations of these modeling techniques to different core restraint design concepts can be readily achieved. 27 figures.

  11. Safety design of prototype fast breeder reactor

    SciTech Connect

    Bhoje, S.B.; Chetal, S.C.; Singh, Om Pal [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2004-07-01

    The basic design and safety design of Prototype Fast Breeder Reactor (PFBR) is presented. Design aspects covered include safety classification, seismic categorization, design basis conditions, design safety limits, core physics, core monitoring, shutdown system, decay heat removal system, protection against sodium leaks and tube leaks in steam generator, plant layout, radiation protection, event analysis, beyond design basis accidents, integrity of primary containment, reactor containment building and design pressure resulting from core disruptive accident. The measures provided in the design represent a robust case of the safety of the reactor. (authors)

  12. The Core Velocity Dispersion (CVD) for Taurus Dense Core Clusters

    NASA Astrophysics Data System (ADS)

    Li, Di; Qian, L.

    2012-05-01

    We define a statistical measurement--Core Velocity Dispersion (CVD) for the dynamics of a dense core cluster. To obtain a well defined CVD requires a spectroscopic dense core sample located in a contiguous region. We measure CVD for Taurus cores utilizing the 100 d^2 13CO map corrected for depletion. The Taurus CVD has the same power law as that of the Larson's law. No sign of additional energy input is seen.

  13. Development of Air Core Type 500 kV HV Pulse Transformer

    Microsoft Academic Search

    S. C. Kim; S. S. Park; S. H. Kim; H. Heo; S. H. Nam; S. T. Ko

    2005-01-01

    Cylindrical type air core pulse transformers capable of passing high voltage and energy pulse waveforms with high efficiency and low distortion require a much more delicate design balance of physical dimensions and electrical parameters than iron or ferrite core units. The structure of an air core high voltage pulse transformer is relatively simple, but considerable attention is needed to prevent

  14. A high-voltage pulse transformer with a modular ferrite core

    Microsoft Academic Search

    Z. Liu; G. J. J. Winands; K. Yan; A. J. M. Pemen; E. J. M. van Heesch

    2008-01-01

    A high ratio (winding ratio of 1:80) pulse transformer with a modular ferrite core was developed for a repetitive resonant charging system. The magnetic core is constructed from 68 small blocks of ferrites, glued together by epoxy resin. This allows a high degree of freedom in choosing core shape and size. Critical issues related to this modular design are the

  15. DANDE: a linked code system for core neutronics\\/depletion analysis

    Microsoft Academic Search

    R. J. LaBauve; T. R. England; D. C. George; R. E. MacFarlane; W. B. Wilson

    1985-01-01

    This report describes DANDE - a modular neutronics, depletion code system for reactor analysis. It consists of nuclear data processing, core physics, and fuel depletion modules, and allows one to use diffusion and transport methods interchangeably in core neutronics calculations. This latter capability is especially important in the design of small modular cores. Additional unique features include the capability of

  16. DANDE: a linked code system for core neutronics\\/depletion analysis

    Microsoft Academic Search

    R. J. LaBauve; T. R. England; D. C. George; R. E. MacFarlane; W. B. Wilson

    1986-01-01

    This report describes DANDE - a modular neutronics, depletion code system for reactor analysis. It consists of nuclear data processing, core physics, and fuel depletion modules, and allows one to use diffusion and transport methods interchangeably in core neutronics calculations. This latter capability is especially important in the design of small modular cores. Additional unique features include the capability of

  17. Mechanical response of carbon fiber composite sandwich panels with pyramidal truss cores

    E-print Network

    Wadley, Haydn

    Mechanical response of carbon fiber composite sandwich panels with pyramidal truss cores Tochukwu panel designs offers novel opportunities for ultralight structures. Here, pyramidal truss sandwich cores-predicts the measurements. The CFRP pyramidal cores investigated here have a similar mechanical performance to CFRP

  18. EEA Technical report No 1/2005 EEA core set of indicators

    E-print Network

    EEA Technical report No 1/2005 EEA core set of indicators Guide ISSN 1725-2237 #12;European Environment Agency EEA core set of indicators -- Guide (EEA Technical report No 1/2005 -- ISSN 1725;EEA core set of indicators Guide EEA Technical report No 1/2005 #12;Cover design: EEA Layout: EEA

  19. Architecture-level Thermal Behavioral Characterization For Multi-Core Microprocessors

    E-print Network

    Tan, Sheldon X.-D.

    Architecture-level Thermal Behavioral Characterization For Multi-Core Microprocessors Duo Li Dept-performance multi-core microprocessor design. We propose a new approach, called ThermPOF, to build the thermal-space form. Experimental results on a practi- cal quad-core microprocessor show that generated thermal

  20. The numerical analyze of the six-core photonic liquid crystal fibers

    Microsoft Academic Search

    Weimin Sun; Xiaoqi Liu

    2010-01-01

    We demonstrate a new kind of six cores photonic liquid crystal fibers (PLCFs) which are arrayed in a ring-type geometry and separated by the air holes. Based on the single mode conditions of PLCFs we found, we design structure parameters of the liquid cores to fulfill that only the fundamental mode transmits in the liquid cores. Through changing the wavelength,

  1. All-University Core Curriculum All-University Core Curriculum

    E-print Network

    Stephens, Graeme L.

    All-University Core Curriculum _______________ 2.3 Page 1 All-University Core Curriculum Office-UNIVERSITY CORE CURRICULUM (AUCC) All Colorado State University students share a learning experience in common. Mathematics1 3 2. Advanced Writing (3 credits)2, 3 3. Foundations and Perspectives (22 credits) A. Biological

  2. Measuring Core Inflation

    Microsoft Academic Search

    Michael F. Bryan; Stephen G. Cecchetti

    1993-01-01

    In this paper, we investigate the use of limited-information estimators as measures of core inflation. Employing a model of asymmetric supply disturbances, with costly price adjustment, we show how the observed skewness in the cross-sectional distribution of inflation can cause substantial noise in the aggregate price index at high frequencies. The model suggests that limited-influence estimators, such as the median

  3. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

    1996-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  4. Banded electromagnetic stator core

    DOEpatents

    Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

    1994-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  5. Banded electromagnetic stator core

    DOEpatents

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1994-04-05

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

  6. Demonstration program for a mini in-core instrument assembly

    SciTech Connect

    Kantrowitz, M.L.; Terney, W.B. (ABB Combustion Engineering Nuclear Power, Inc., Windsor, CT (United States))

    1992-01-01

    Fixed in-core detectors have traditionally been used in ABB Combustion Engineering (ABB-CE) nuclear steam supply systems to provide signals for observation of the core power distribution and on-line monitoring of reactor core behavior and margins to thermal limits. The fixed in-core detectors are contained in in-core instrument (ICI) assemblies, which are inserted into {approximately}25% of the fuel assemblies in the core. In the System 80 design, each ICI assembly includes a central calibration tube that permits access of a movable detector into that assembly. However, operating experience at System 80 plants has demonstrated that the fixed detector system alone satisfies all core monitoring and core surveillance requirements. Therefore, the movable detector system is not needed and is, in fact, no longer used. However, the presence of the central calibration tube feature can be utilized to improve the performance of the ICIs by extending the useful lifetime of the rhodium detectors that comprise the instrument. This paper reports the results to date of a demonstration program for the mini ICI assemblies designed to (a) validate the mini ICIs as equivalent replacements for the standard ICIs and (b) refine the rhodium detector sensitivity depletion law to permit higher detector depletions than currently allowed.

  7. Operating experience with the multienrichment initial core of the boiling water reactor Kashiwazaki-Kariwa Unit 5

    Microsoft Academic Search

    Takaaki Mochida; Mitsunari Nakamura; Junichi Yamashita; Hiromi Maruyama; Sakae Muto; Shigeru Kasai

    1996-01-01

    The multienrichment boiling water reactor (BWR) initial core design was first applied to the Kashiwazaki-Kariwa Nuclear Power Station Unit 5 [1100-MW (electric) BWR] in Japan. This core is designed to improve fuel discharge exposure, capacity factors, and operability. The design study shows that three types of fuel bundles with different enrichments are suitable to achieve the design targets. Three bundle

  8. Central core disease

    PubMed Central

    Jungbluth, Heinz

    2007-01-01

    Central core disease (CCD) is an inherited neuromuscular disorder characterised by central cores on muscle biopsy and clinical features of a congenital myopathy. Prevalence is unknown but the condition is probably more common than other congenital myopathies. CCD typically presents in infancy with hypotonia and motor developmental delay and is characterized by predominantly proximal weakness pronounced in the hip girdle; orthopaedic complications are common and malignant hyperthermia susceptibility (MHS) is a frequent complication. CCD and MHS are allelic conditions both due to (predominantly dominant) mutations in the skeletal muscle ryanodine receptor (RYR1) gene, encoding the principal skeletal muscle sarcoplasmic reticulum calcium release channel (RyR1). Altered excitability and/or changes in calcium homeostasis within muscle cells due to mutation-induced conformational changes of the RyR protein are considered the main pathogenetic mechanism(s). The diagnosis of CCD is based on the presence of suggestive clinical features and central cores on muscle biopsy; muscle MRI may show a characteristic pattern of selective muscle involvement and aid the diagnosis in cases with equivocal histopathological findings. Mutational analysis of the RYR1 gene may provide genetic confirmation of the diagnosis. Management is mainly supportive and has to anticipate susceptibility to potentially life-threatening reactions to general anaesthesia. Further evaluation of the underlying molecular mechanisms may provide the basis for future rational pharmacological treatment. In the majority of patients, weakness is static or only slowly progressive, with a favourable long-term outcome. PMID:17504518

  9. Partially Reconfigurable Cores for Xilinx Virtex

    Microsoft Academic Search

    Matthias Dyer; Christian Plessl; Marco Platzner

    2002-01-01

    Recent generations of high-density and high-speed FPGAs provide a sucient capacity for implementing complete congurable systems on a chip (CSoCs). Hybrid CPUs that combine standard CPU cores with recongurable coprocessors are an important subclass of CSoCs. With partially recongurable FPGAs, coprocessors can be loaded on demand while the CPU remains running. However, the lack of high-level design tools for partial

  10. Saturated Cores FCL—A New Approach

    Microsoft Academic Search

    V. Rozenshtein; A. Friedman; Y. Wolfus; F. Kopansky; E. Perel; Y. Yeshurun; Z. Bar-Haim; Z. Ron; E. Harel; N. Pundak

    2007-01-01

    The saturated cores FCL exhibits several attractive technological advantages: inherent fail-safe and selectivity design, superconductivity is maintained during both nominal and fault states, the limiting process as well as the recovery after fault are passive and immediate, operation in limiting state is not time-limited, and the superconducting bias coil is made of wires available as commercial shelf-product. Despite these advantages,

  11. A search for minimum volume of Breed and Burn cores

    SciTech Connect

    Di Sanzo, C.; Greenspan, E. [Dept. of Nuclear Engineering, Univ. of California, Berkeley Etcheverry Hall, Berkeley, CA 94720 (United States)

    2012-07-01

    The objective of the present study is to quantify the minimum volume a Breed and Burn (B and B) core can be designed to have and the corresponding burnup required for sustaining the breed-and-burn mode of operation based on neutronics; radiation damage constraints are ignored. The minimum radius for an idealized spherical B and B reactor is 136 cm or 110 cm for, respectively, 40% or 28% coolant volume fraction. The peak required burnup is about 25%. The minimum volume of a more realistic cylindrical B and B core is estimated to be only {approx}15% larger than that of the idealized spherical core but is only 43% of the volume of the medium-size B and B core previously designed to fit within the S-Prism reactor vessel. Thus it appears that SMR s can, in principle, be designed to have a B and B core. It was also found that the minimum volume B and B core does not necessarily coincide with the maximum permissible leakage from a core that can sustain the B and B mode of operation. (authors)

  12. Core-Mathematics Project (CPMP)

    NSDL National Science Digital Library

    The Core-Mathematics Project (CPMP) involved four years of research, development, and evaluation in over 35 high schools in Alaska, California, Colorado, Georgia, Idaho, Iowa, Kentucky, Michigan, Ohio, South Carolina, and Texas. With funding from the National Science Foundation the project sought to develop student and teacher materials for "a comprehensive Standards-based three-year high school mathematics curriculum for all students, plus a fourth-year course continuing the preparation of students for college mathematics." The four-year curriculum replaces the traditional Algebra-Geometry-Advanced Algebra / Trigonometry-Precalculus sequence by teaching algebra and geometry every year while also introducing new topics such as statistics and discrete mathematics. The curriculum emphasizes mathematical modeling and applications and received the highest designation of "exemplary" from the U.S. Department of Education Expert Panel on Mathematics. Although the CPMP curriculum must be purchased from the publisher Glencoe / McGraw-Hill, sample materials and details about the curriculum, including approaches to assessment and evaluations of the curriculum are available online. The website describes features of the CPMP curriculum, overviews the mathematical content, and discusses issues for instructional design and implementation. Information on upcoming conferences and workshops, and other online articles are also available.

  13. Models of the earth's core

    Microsoft Academic Search

    D. J. Stevenson

    1981-01-01

    The combination of seismology, high pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to strong constraints on core models. The synthesis presented here is devoted to the defense of the following properties: (1) core formation was contemporaneous with earth accretion; (2) the outer, liquid core is predominately iron but cannot be purely iron;

  14. Implement of time division multiplexing high speed programmable Viterbi decoder IP core

    NASA Astrophysics Data System (ADS)

    Wu, Lan; Chen, Qiliang

    2013-03-01

    The programmable Time Division multiplexing high Viterbi decoder IP core is studied in this paper. According to the characteristics of multiple communication system, the method of programmable time-division multiplexing is puts forward, the high-performance and less resource occupy IP core is designed. Based on SMIC 0.18um CMOS technology, the ASIC of IP core is test. The test results show that the IP core areas, power and frequency could satisfy demand of real-time communication.

  15. Instructional Management Plans for the Cooperative Industrial Education Core Curriculum.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Instructional Materials Lab.

    These Instructional Management Plans (IMPs) are designed to assist teacher-coordinators of cooperative industrial education (CIE) in the design of application experiences for each task of each core competency area. They are intended to help the CIE teacher-coordinator direct the learning of occupational competencies by helping the student-learners…

  16. Evaluation of LMR (liquid metal reactors) core support concepts under seismic events

    SciTech Connect

    Wu, Ting-shu; Seidensticker, R.W.

    1989-01-01

    In the design of the core support system for liquid metal reactors (LMR) against earthquakes, the major concerns are directed toward the structural integrity as well as the reactivity control. This means that, in addition to the stress levels, maximum displacements and accelerations should also be within their allowable limits. This investigation studies the seismic responses of a large pool-type LMR with different design approaches to support the reactor core. Different core support designs yield different frequency ranges and responses. Responses of these designs to the given floor response spectra are required to satisfy a set of criteria which are common to all designs. 5 refs., 4 figs.

  17. Leakage effect on lattice homogenization and core reactivity

    SciTech Connect

    Rentai Chiang (General Electric Co., San Jose, CA (United States))

    1991-01-01

    The zero-leakage boundary condition has been used to generate lattice-homogenized cross sections for core simulation. Due to finite size of a core and differences in neighboring lattice design, exposure, and control state, significant leakage actually exists between adjacent lattices. The author has developed an approximate-leakage lattice homogenization method by using the uniform-leakage boundary condition. The leakage effect has been studied on lattice homogenization and core reactivity through three fictitious slab reactors by comparing reactivities among the heterogeneous core and the homogenized core with exact-, uniform-, or zero-leakage lattice boundary conditions and with global leakage. Moreover, the relationship among various leakage methods including a leakage boundary-condition perturbation method is discussed.

  18. Combustion and core noise

    NASA Astrophysics Data System (ADS)

    Mahan, J. Robert; Karchmer, Allen

    1991-08-01

    Two types of aircraft power plant are considered: the gas turbine and the reciprocating engine. The engine types considered are: the reciprocating engine, the turbojet engine, the turboprop engine, and the turbofan engine. Combustion noise in gas turbine engines is discussed, and reciprocating-engine combustion noise is also briefly described. The following subject areas are covered: configuration variables, operational variables, characteristics of combustion and core noise, sources of combustion noise, combustion noise theory and comparison with experiment, available prediction methods, diagnostic techniques, measurement techniques, data interpretation, and example applications.

  19. Core 4: Image Bank

    NSDL National Science Digital Library

    This Image Bank supplements the coursework for Core 4: The Shaping of the Modern World, an introductory course offered by the History Department of Brooklyn College. The Image Bank indexes numerous historical images spanning from the Scientific Revolution to the present. The images are divided into eight major topic indexes: Ancien Regime and Critics; Age of Revolutions; Industry and Society; Liberalism and Nationalism; Varieties of Imperialism; The World Turned Upside Down; Fascism, Depression & WWII; and, The World Since 1945. Indexes for major topics contain clustered subtopics, allowing users to locate relevant images quickly. This Image Bank presents students and educators with a valuable, visual method for understanding Modern Western History.

  20. Mercury's inner core size and core crystallization regime

    NASA Astrophysics Data System (ADS)

    Dumberry, Mathieu; Rivoldini, Attilio

    2015-04-01

    Earth-based radar observation of Mercury's rotation vector combined with gravity observation by the MESSENGER spacecraft yield a measure of Mercury's moment of inertia and the amplitude of the 88-day libration of its silicate shell. These two geodetic constraints provide information on Mercury's interior structure, including the presence of a fluid core, the radius of the core-mantle boundary and the bulk densities of the core and mantle. In this work, we show how they further provide information on the size of the solid inner core and on the crystallization regime of the fluid core. If Mercury's fluid core is a Fe-FeS alloy, the largest inner core compatible with geodetic observations is 1325 ± 250 km. The crystallization scenario that best fits the observations involves the formation of Fe-snow within the fluid core. Snow formation can be restricted to a thin layer or can occupy the whole of the fluid core depending on inner core size and initial sulfur concentration. Our results offer important constraints for dynamo models of Mercury, but also advocate for the further development of models that incorporate the various features of snow formation.

  1. Power excursion analysis for high burnup cores

    SciTech Connect

    Diamond, D.J.; Neymotin, L.; Kohut, P. [Brookhaven National Lab., Upton, NY (United States)

    1996-02-01

    A study was undertaken of power excursions in high burnup cores. There were three objectives in this study. One was to identify boiling water reactor (BWR) and pressurized water reactor (PWR) transients in which there is significant energy deposition in the fuel. Another was to analyze the response of BWRs to the rod drop accident (RDA) and other transients in which there is a power excursion. The last objective was to investigate the sources of uncertainty in the RDA analysis. In a boiling water reactor, the events identified as having significant energy deposition in the fuel were a rod drop accident, a recirculation flow control failure, and the overpressure events; in a pressurized water reactor, they were a rod ejection accident and boron dilution events. The RDA analysis was done with RAMONA-4B, a computer code that models the space- dependent neutron kinetics throughout the core along with the thermal hydraulics in the core, vessel, and steamline. The results showed that the calculated maximum fuel enthalpy in high burnup fuel will be affected by core design, initial conditions, and modeling assumptions. The important uncertainties in each of these categories are discussed in the report.

  2. High-temperature superconducting magnet for use in saturated core FCL

    Microsoft Academic Search

    Z Bar-Haim; A Friedman; Y Wolfus; V Rozenshtein; F Kopansky; Z Ron; E Harel; N Pundak; Y Yeshurun

    2008-01-01

    A HTS magnet system used in a saturated core Fault Current Limiter (FCL) device is described. The superconducting magnet, operating in DC mode, is used in such FCL design for saturating the magnetic core and maintaining low device impedance under nominal conditions. The unique design of the FCL poses constrains on the DC HTS magnet. A model which meets all

  3. Development of a multicell methodology to account for heterogeneous core effects in the core-analysis diffusion code

    SciTech Connect

    Shen, W. [Atomic Energy of Canada Limited, 2251 Speakman Drive, Mississauga, Ont. L5K 1B2 (Canada)

    2006-07-01

    In CANDU R reactor calculations, the lattice-cell cross sections are calculated with WIMS-AECL, and the three-dimensional core neutron-flux and power distributions are calculated with RFSP-IST. The lattice-cell cross sections employed in RFSP-IST and in many other commercial core-analysis diffusion codes are usually based on the use of single-lattice-cell calculations, without considering the effects of the environment. This approximation is not sufficiently accurate for heterogeneous core configurations in the ACR-1000{sup TM}. A multicell correction method is therefore developed in RFSP-IST to account for heterogeneous core effects in the design and analysis of ACR-1000. The calculation results show that the multicell methodology developed in RFSP-IST is effective, generic, and it works well for ACR core analysis. (authors)

  4. Plasma core reactor applications

    NASA Technical Reports Server (NTRS)

    Latham, T. S.; Rodgers, R. J.

    1976-01-01

    Analytical and experimental investigations were conducted to demonstrate the feasibility of fissioning uranium plasma core reactors and to characterize space and terrestrial applications for such reactors. Uranium hexafluoride fuel is injected into core cavities and confined away from the surface by argon buffer gas injected tangentially from the peripheral walls. Radiant heat transfer calculations were performed for a six-cavity reactor configuration. Axial working fluid channels are located along a fraction of each cavity peripheral wall. Results of calculations for outward-directed radiant energy fluxes corresponding to radiating temperatures of 2000 to 5000 K indicate total operating pressures from 80 to 650 atm, centerline temperatures from 6900 to 30,000 K, and total radiated powers from 25 to 2500 MW, respectively. Applications are described for this type of reactor such as (1) high-thrust, high specific impulse space propulsion, (2) highly efficient systems for generation of electricity, and (3) hydrogen or synthetic fuel production systems using the intense radiant energy fluxes.

  5. Quiet Clean Short-Haul Experimental Engine (QCSEE). Preliminary analyses and design report, volume 2

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The experimental and flight propulsion systems are presented. The following areas are discussed: engine core and low pressure turbine design; bearings and seals design; controls and accessories design; nacelle aerodynamic design; nacelle mechanical design; weight; and aircraft systems design.

  6. Spacecraft transformer and inductor design

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1977-01-01

    The conversion process in spacecraft power electronics requires the use of magnetic components which frequently are the heaviest and bulkiest items in the conversion circuit. This handbook pertains to magnetic material selection, transformer and inductor design tradeoffs, transformer design, iron core dc inductor design, toroidal power core inductor design, window utilization factors, regulation, and temperature rise. Relationships are given which simplify and standardize the design of transformers and the analysis of the circuits in which they are used. The interactions of the various design parameters are also presented in simplified form so that tradeoffs and optimizations may easily be made.

  7. Low loss and broadband hollow-core photonic crystal fibers

    Microsoft Academic Search

    Y. Y. Wang; F. Gerome; G. Humbert; J. M. Blondy; F. Benabid

    2011-01-01

    We report on recent developments on fabrication and optical guidance of Kagome-lattice hollow-core photonic crystal fiber (HC-PCF). These include the design and fabrication of a hypocycloid-shaped core Kagome HC-PCF that combines a record optical attenuation with a baseline exhibiting ~180 dB\\/km over a transmission bandwidth larger than 200 THz. These results are corroborated with theoretical simulations which show that both

  8. Guiding properties of kagome-lattice hollow-core fibers

    Microsoft Academic Search

    E. Coscelli; F. Poli; D. Passaro; A. Cucinotta; S. Selleri

    2010-01-01

    Photonic crystal fibers with kagome lattice are a particular kind of micostructured hollow-core fibers whose cross-section is characterized by a web of thin silica struts intersecting in a Star-of-David pattern. Such fibers show unusual properties, such as light confinement in the air-core in absence of a full photonic bandgap. The primary design parameter for such fibers is the strut thickness,

  9. THz propagation in kagome hollow-core microstructured fibers.

    PubMed

    Anthony, Jessienta; Leonhardt, Rainer; Leon-Saval, Sergio G; Argyros, Alexander

    2011-09-12

    We demonstrate single mode terahertz (THz) guidance in hollow-core kagome microstructured fibers over a broad frequency bandwidth. The fibers are characterized using a THz time-domain spectroscopy (THz-TDS) setup, incorporating specially designed THz lenses to achieve good mode overlap with the fundamental mode field distribution. Losses 20 times lower than the losses of the fiber material are observed in the experiments, as well as broad frequency ranges of low dispersion, characteristic of hollow-core fibers. PMID:21935215

  10. Microprocessor based testing for core-based system on chip

    Microsoft Academic Search

    Christos A. Papachristou; F. Martin; Mehrdad Nourani

    1999-01-01

    The purpose of this paper is to develop a flexible design fortest methodology for testing a core-based system on chip(SOC). The novel feature of the approach is the use anembedded microprocessor\\/memory pair to test the remainingcomponents of the SOC. Test data is downloaded usingDMA techniques directly into memory while the microprocessoruses the test data to test the core. The test

  11. A method for reducing encapsulation stress to ferrite pot cores

    SciTech Connect

    Sanchez, R.O.

    1994-08-01

    This paper describes a method of reducing the mechanical stress caused when a ferrite pot core is encapsulated in a rigid epoxy. the stresses are due to the differences of coefficient of thermal expansion between the two materials. A stress relief medium, phenolic micro-balloon-filled, syntactic polysulfide, is molded into the shape of the pot core. The molded polysulfide is bonded to the core prior to encapsulation. The new package design has made a significant difference in the ability to survive temperature cycles.

  12. Feasibility study of full-reactor gas core demonstration test

    NASA Technical Reports Server (NTRS)

    Kunze, J. F.; Lofthouse, J. H.; Shaffer, C. J.; Macbeth, P. J.

    1973-01-01

    Separate studies of nuclear criticality, flow patterns, and thermodynamics for the gas core reactor concept have all given positive indications of its feasibility. However, before serious design for a full scale gas core application can be made, feasibility must be shown for operation with full interaction of the nuclear, thermal, and hydraulic effects. A minimum sized, and hence minimum expense, test arrangement is considered for a full gas core configuration. It is shown that the hydrogen coolant scattering effects dominate the nuclear considerations at elevated temperatures. A cavity diameter of somewhat larger than 4 ft (122 cm) will be needed if temperatures high enough to vaporize uranium are to be achieved.

  13. Performance effects of device scale and core aspect-ratio on dielectric-core circuit board transformers

    NASA Astrophysics Data System (ADS)

    Bowen, David; Lee, Andrew; Krafft, Charles; Mayergoyz, Isaak D.

    2014-05-01

    Broadband dielectric-core toroidal coupling transformers are attractive alternatives to magnetic core devices due to their lower cost, lower losses, and ease of integration into already established fabrication processes. However, the performance of these transformers depends greatly on device geometry, from both inductive and capacitive effects. In this study, the inductive coupling performance of candidate designs of such transformers fabricated on printed circuit board were experimentally measured as the core aspect-ratio and turn number were varied. A coupling minimum is observed, and this is determined to be the result of leakage inductance changing linearly, and mutual inductance changing quadratically with core aspect-ratio. The relationship of these dependencies to the device geometry are discussed, as well as the trade-offs that exist when designing a device that performs away from this coupling minimum.

  14. Pulse transformer design study

    Microsoft Academic Search

    H. Aslin

    1977-01-01

    This final report describes the design, development of fabrication techniques, fabrication, and testing of two uniform field, air core pulse transformers. The described transformer design minimizes the volume of dielectric material, which provides turn-to-turn insulation, reduces stray series inductance, and thus improves the transformer high frequency response in comparison to conventional pulse transformers. The described pulse transformers are intended for

  15. Magnetic and Electrical Characteristics of Permalloy Thin Tape Bobbin Cores

    NASA Technical Reports Server (NTRS)

    Schwarze, Gene E.; Wieserman, William R.; Niedra, Janis M.

    2005-01-01

    The core loss, that is, the power loss, of a soft ferromagnetic material is a function of the flux density, frequency, temperature, excitation type (voltage or current), excitation waveform (sine, square, etc.) and lamination or tape thickness. In previously published papers we have reported on the specific core loss and dynamic B-H loop results for several polycrystalline, nanocrystalline, and amorphous soft magnetic materials. In this previous research we investigated the effect of flux density, frequency, temperature, and excitation waveform for voltage excitation on the specific core loss and dynamic B-H loop. In this paper, we will report on an experimental study to investigate the effect of tape thicknesses of 1, 1/2, 1/4, and 1/8-mil Permalloy type magnetic materials on the specific core loss. The test cores were fabricated by winding the thin tapes on ceramic bobbin cores. The specific core loss tests were conducted at room temperature and over the frequency range of 10 kHz to 750 kHz using sine wave voltage excitation. The results of this experimental investigation will be presented primarily in graphical form to show the effect of tape thickness, frequency, and magnetic flux density on the specific core loss. Also, the experimental results when applied to power transformer design will be briefly discussed.

  16. Multi-core advantages for mask data preparation

    NASA Astrophysics Data System (ADS)

    Yeap, Johnny; Nogatch, John

    2009-04-01

    Smaller design pattern feature sizes continue to increase mask data file sizes, which increases mask data processing (MDP) times. To satisfy the need for faster turn-around-time, MDP has progressively migrated from single-computer computation, to multi-threading, and then to distributed processing on multiple computers. The availability of low cost multi-core processors can be used advantageously to reduce Mask Data Preparation runtime. Compared to single core processors, multi-core processor have higher performance, however, total available memory and I/O bandwidth need to be increased proportionally with the additional cores. Memory per core and available I/O bandwidth limit the maximum number of cores that can be effective with distributed processing. When a single job is broken down to 2 or more tasks, the granularity of the tasks influences the efficiency of the processing. Smaller tasks allow for smaller memory footprint, better distribution of tasks and increased scalability, but increase input file access time and reduce output data compaction. By choosing a combination of multi-threading and distributed processing, faster run-time and better scalability can be achieved, as compared to either technique alone. The optimal configuration depends on the number of cores per processor, number of processors and memory per core.

  17. Thermal-hydraulic analysis for wire-wrapped PWR cores

    Microsoft Academic Search

    P. Diller; N. Todreas; P. Hejzlar

    2009-01-01

    This work focuses on the steady-state and transient thermal-hydraulic analyses for PWR cores using wire wraps in a hexagonal array with either U (45% w\\/o)–ZrH1.6 (referred to as U–ZrH1.6) or UO2 fuels. Equivalences (thermal-hydraulic and neutronic) were created between grid spacer and wire wrap designs, and were used to apply results calculated for grid spacers to wire wrap designs. Design

  18. Next Generation CANDU Core Physics Innovations

    SciTech Connect

    Chan, P.S.W.; Hopwood, J.M.; Love, J.W. [Atomic Energy of Canada Ltd., Ontario (Canada)

    2002-07-01

    NG CANDU is the 'Next Generation' CANDU{sup R} reactor, aimed at producing electrical power at a capital cost significantly less than that of the current reactor designs. A key element of cost reduction is the use of H{sub 2}O as coolant and Slightly Enriched Uranium fuel in a tight D{sub 2}O-moderated lattice. The innovations in the CANDU core physics result in substantial improvements in economics as well as significant enhancements in reactor licensability, controllability, and waste reduction. The full-core coolant-void reactivity in NG CANDU is about -3 mk. Power coefficient is substantially negative. Fuel burnup is about three times the current natural-uranium burnup. (authors)

  19. MOX fuel arrangement for nuclear core

    DOEpatents

    Kantrowitz, M.L.; Rosenstein, R.G.

    1998-10-13

    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. 38 figs.

  20. MOX fuel arrangement for nuclear core

    DOEpatents

    Kantrowitz, Mark L. (Portland, CT); Rosenstein, Richard G. (Windsor, CT)

    2001-07-17

    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.

  1. Allosteric Inhibition Through Core Disruption

    SciTech Connect

    Horn, James R.; Shoichet, Brian K. (NWU); (UCSF)

    2010-03-05

    Although inhibitors typically bind pre-formed sites on proteins, it is theoretically possible to inhibit by disrupting the folded structure of a protein or, in the limit, to bind preferentially to the unfolded state. Equilibria defining how such molecules act are well understood, but structural models for such binding are unknown. Two novel inhibitors of {beta}-lactamase were found to destabilize the enzyme at high temperatures, but at lower temperatures showed no preference for destabilized mutant enzymes versus stabilized mutants. X-ray crystal structures showed that both inhibitors bound to a cryptic site in {beta}-lactamase, which the inhibitors themselves created by forcing apart helixes 11 and 12. This opened up a portion of the hydrophobic core of the protein, into which these two inhibitors bind. Although this binding site is 16 {angstrom} from the center of the active site, the conformational changes were transmitted through a sequence of linked motions to a key catalytic residue, Arg244, which in the complex adopts conformations very different from those in catalytically competent enzyme conformations. These structures offer a detailed view of what has heretofore been a theoretical construct, and suggest the possibility for further design against this novel site.

  2. Core foundations of abstract geometry.

    PubMed

    Dillon, Moira R; Huang, Yi; Spelke, Elizabeth S

    2013-08-27

    Human adults from diverse cultures share intuitions about the points, lines, and figures of Euclidean geometry. Do children develop these intuitions by drawing on phylogenetically ancient and developmentally precocious geometric representations that guide their navigation and their analysis of object shape? In what way might these early-arising representations support later-developing Euclidean intuitions? To approach these questions, we investigated the relations among young children's use of geometry in tasks assessing: navigation; visual form analysis; and the interpretation of symbolic, purely geometric maps. Children's navigation depended on the distance and directional relations of the surface layout and predicted their use of a symbolic map with targets designated by surface distances. In contrast, children's analysis of visual forms depended on the size-invariant shape relations of objects and predicted their use of the same map but with targets designated by corner angles. Even though the two map tasks used identical instructions and map displays, children's performance on these tasks showed no evidence of integrated representations of distance and angle. Instead, young children flexibly recruited geometric representations of either navigable layouts or objects to interpret the same spatial symbols. These findings reveal a link between the early-arising geometric representations that humans share with diverse animals and the flexible geometric intuitions that give rise to human knowledge at its highest reaches. Although young children do not appear to integrate core geometric representations, children's use of the abstract geometry in spatial symbols such as maps may provide the earliest clues to the later construction of Euclidean geometry. PMID:23940342

  3. Design of scalable Java communication middleware for

    E-print Network

    Touriño, Juan

    Design of scalable Java communication middleware for multi-core systems Sabela Ramos, Guillermo L; Java Multi-threading; Shared Memory; Multi-core Architectures; Message-Passing in Java (MPJ) 1 for multi-core systems. smdev provides a simple and powerful messaging API that is able to exploit

  4. Noncooperative selection of the core

    Microsoft Academic Search

    Huibin Yan

    2000-01-01

    For bargaining environments given by transferable utility charac- teristic functions that are zero-normalized and admit a nonempty core, we find a class of random-proposer bargaining games, generalized from Okada (1993), such that there is a one-to-one mapping from these games to the core, each game realizes the corresponding core allocation as its unique (ex ante) Stationary Subgame Perfect Equilibrium (SSPE)

  5. Core-selecting package auctions

    Microsoft Academic Search

    Robert Day; Paul Milgrom

    2008-01-01

    Auctions that select core allocations with respect to reported values generate competitive levels of sales revenues at equilibrium\\u000a and limit bidder incentives to use shills. Among core-selecting auctions, the ones that minimize seller revenues also maximize\\u000a incentives for truthful reporting, produce the Vickrey outcome when that lies in the core and, in contrast to the Vickrey\\u000a auction, and create no

  6. The GRIP Ice Coring Effort

    NSDL National Science Digital Library

    This NOAA website provides a summary of the Greenland Ice Core Project, which resulted in a 3029 m long ice core drilled in Central Greenland from 1989 to 1992. The core reveals information on past environmental and climatic changes that are stored in the ice. Isotopic studies and various atmospheric constituents in the core have revealed a detailed record of climatic variations that span more than 100,000 years. The final report from the project may be downloaded as either a Word or ASCII file.

  7. ac power control in the Core Flow Test Loop

    SciTech Connect

    McDonald, D.W.

    1980-01-01

    This work represents a status report on a development effort to design an ac power controller for the Core Flow Test Loop. The Core Flow Test Loop will be an engineering test facility which will simulate the thermal environment of a gas-cooled fast-breeder reactor. The problems and limitations of using sinusoidal ac power to simulate the power generated within a nuclear reactor are addressed. The transformer-thyristor configuration chosen for the Core Flow Test Loop power supply is presented. The initial considerations, design, and analysis of a closed-loop controller prototype are detailed. The design is then analyzed for improved performance possibilities and failure modes are investigated at length. A summary of the work completed to date and a proposed outline for continued development completes the report.

  8. Inner core structure behind the PKP core phase triplication

    NASA Astrophysics Data System (ADS)

    Blom, Nienke A.; Deuss, Arwen; Paulssen, Hanneke; Waszek, Lauren

    2015-06-01

    The structure of the Earth's inner core is not well known between depths of ˜100-200 km beneath the inner core boundary. This is a result of the PKP core phase triplication and the existence of strong precursors to PKP phases, which hinder the measurement of inner core compressional PKIKP waves at epicentral distances between roughly 143 and 148°. Consequently, interpretation of the detailed structure of deeper regions also remains difficult. To overcome these issues we stack seismograms in slowness and time, separating the PKP and PKIKP phases which arrive simultaneously but with different slowness. We apply this method to study the inner core's Western hemisphere beneath South and Central America using paths travelling in the quasi-polar direction between 140 and 150° epicentral distance, which enables us to measure PKiKP-PKIKP differential traveltimes up to greater epicentral distance than has previously been done. The resulting PKiKP-PKIKP differential traveltime residuals increase with epicentral distance, which indicates a marked increase in seismic velocity for polar paths at depths greater than 100 km compared to reference model AK135. Assuming a homogeneous outer core, these findings can be explained by either (i) inner core heterogeneity due to an increase in isotropic velocity or (ii) increase in anisotropy over the studied depth range. Although this study only samples a small region of the inner core and the current data cannot distinguish between the two alternatives, we prefer the latter interpretation in the light of previous work.

  9. Core Optimization of a Deep-Burn Pebble Bed Reactor

    SciTech Connect

    Brian Boer; Abderrafi M. Ougouag

    2010-06-01

    Achieving a high fuel burnup in the Deep-Burn (DB) pebble bed reactor design, while remaining within the limits for fuel temperature, power peaking and temperature reactivity feedback, is challenging. The high content of Pu and Minor Actinides in the Deep-Burn fuel significantly impacts the thermal neutron energy spectrum as compared to a ’standard’ UO2 fueled core. This can result in power and temperature peaking in the pebble bed core in locally thermalized regions near the graphite reflectors. Furthermore, the interplay of the Pu resonances of the neutron absorption cross sections at low-lying energies can lead to a positive temperature reactivity coefficient for the graphite moderator at certain operating conditions. The DB concept focuses on the destruction of spent fuel transuranics in TRISO coated particle fueled gas-cooled reactors with the aim of a fractional fuel burnup of 60-70% in fissions per initial metal atom (FIMA), using a single-pass, multi in-core fuel (re)cycling scheme. In principle, the DB pebble bed concept employs the same reactor designs as the present low enriched uranium core designs, i.e. the 400 MWth Pebble Bed Modular Reactor (PBMR-400). A Pu and Minor Actinide fueled PBMR-400 design serves as the starting point for a core optimization study. The fuel temperature, power peak, temperature reactivity coefficients, and burnup capabilities of the modified designs are analyzed with the PEBBED code. A code-to-code coupling with the PASTA code allows for the analysis of the TRISO fuel performance for both normal and Loss Of Forced Cooling conditions. An improved core design is sought, maximizing the fuel discharge burnup, while retaining negative temperature reactivity feedback coefficients for the entire temperature range and avoiding high fuel temperatures (fuel failure probabilities).

  10. IN-CORE FUEL MANAGEMENT: PWR Core Calculations Using MCRAC

    NASA Astrophysics Data System (ADS)

    Petrovi?, B. G.

    1991-01-01

    The following sections are included: * INTRODUCTION * IN-CORE FUEL MANAGEMENT CALCULATIONS * In-Core Fuel Management * Methodological Problems of In-Core Fuel Management * In-Core Fuel Management Analytical Tools * PENN STATE FUEL MANAGEMENT PACKAGE * Penn State Fuel Management Package (PFMP) * Assembly Data Description (ADD) * Linking PSU-LEOPARD and MCRAC: An Example * MULTICYCLE REACTOR ANALYSIS CODE (MCRAC) * Main Features and Options of MCRAC code * Core geometry * Diffusion equations * 1.5-group model * Multicycle neutronic analysis * Multicycle cost analysis * Criticality search * Power-dependent xenon feedback calculations * Control rod and burnable absorber simulation * Search for LP with flat BOC power distribution * Artificial ADD option * Variable dimensioning technique * RBI version of MCRAC code * Programming changes in PC version * Fuel interchange option * MCRAC Input/Output * General input description * Sample input * Sample output * EXPERIENCE WITH MCRAC CODE * CONCLUSIONS * REFERENCES

  11. Crystalline silicon core fibres from aluminium core preforms.

    PubMed

    Hou, Chong; Jia, Xiaoting; Wei, Lei; Tan, Swee-Ching; Zhao, Xin; Joannopoulos, John D; Fink, Yoel

    2015-01-01

    Traditional fibre-optic drawing involves a thermally mediated geometric scaling where both the fibre materials and their relative positions are identical to those found in the fibre preform. To date, all thermally drawn fibres are limited to the preform composition and geometry. Here, we fabricate a metre-long crystalline silicon-core, silica-cladded fibre from a preform that does not contain any elemental silicon. An aluminium rod is inserted into a macroscopic silica tube and then thermally drawn. The aluminium atoms initially in the core reduce the silica, to produce silicon atoms and aluminium oxide molecules. The silicon atoms diffuse into the core, forming a large phase-separated molten silicon domain that is drawn into the crystalline silicon core fibre. The ability to produce crystalline silicon core fibre out of inexpensive aluminium and silica could pave the way for a simple and scalable method of incorporating silicon-based electronics and photonics into fibres. PMID:25697119

  12. SMA Observations of IRDC Cores: An Active Hot Core and a Quiescent Cold Core

    NASA Astrophysics Data System (ADS)

    Jackson, James M.; Rathborne, J.; Chambers, E.; Zhang, Q.; Simon, R.

    2006-12-01

    Infrared Dark Clouds are a distinct class of interstellar gas cloud identified as dark extinction features seen in silhouette against the bright Galactic background at mid-IR wavelengths. Our recent 1.2 mm continuum emission survey of IRDCs reveal many compact (< 0.5 pc) and massive (10 to 2100 M?) cores within them. These pre-stellar cores hold the key to understanding IRDCs and their role in star formation. About 1/3 of these cores show evidence for active star-formation; shocked gas, outflows, and embedded protostars. The remaining 2/3 of these cores show no signs of active star formation and may be massive starless cores. Here we present recent high angular resolution molecular line maps and sub-mm continuum images obtained with the SMA Interferometer toward two of the most massive cores; one activley forming stars and the other more quiescent. These images elucidate their subparsec structure, and reveal whether the cores are likely to produce a single high-mass star, or a cluster of lower-mass stars. Toward the active core we see many molecular lines indicating that this is a hot molecular core, in an early stage in the formation of a high-mass protostar.

  13. High-voltage air-core pulse transformers

    SciTech Connect

    Rohwein, G.J.

    1981-08-01

    High voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The general types designed for high voltage pulse generation and energy transfer applications are described. Special emphasis is given to pulse charging systems which operate up to the multi-megavolt range. (WHK)

  14. Adult Numeracy Core Curriculum.

    ERIC Educational Resources Information Center

    Steeds, Andrew, Ed.

    Designed primarily for adult literacy teachers and tutors, this curriculum describes the content of what should be taught in numeracy programs in order to meet the individual needs of adults through the selection and teaching of skills appropriate to those adults' needs. An introduction describes national standards and qualifications, learners,…

  15. Pressure coring provides innovative approach

    Microsoft Academic Search

    T. E. Swift; R. Kumar; J. Goodrich; R. L. McCoy

    1981-01-01

    Pressure coring offers the industry a new perspective in tertiary recovery project evaluation. Engineering of experimental tests requires innovative thinking and results in a higher degree of data reliability. Residual water saturation after waterflood should be the primary objective of the experimental project. The project manager should not consider the pressure core as a sole source of data. By combing

  16. Baccalaureate Degree Worksheet Core Curriculum

    E-print Network

    Ickert-Bond, Steffi

    Baccalaureate Degree Worksheet Core Curriculum Core Curriculum Required Credits Communication 9 2 for additional degree requirements. MATHEMATICS (3-4) Complete one of the following: MATH 103X (3)_____ MATH 107X (4)_____ MATH 161X (3)_____ MATH 200X+ (4)_____ MATH 201X+ (4)_____ MATH 202X+ (4)_____ MATH

  17. Viscosity of the Earth's Core

    Microsoft Academic Search

    Roger F. Gans

    1972-01-01

    The viscosity of the earth's core is probably the least well-known physical property of the earth. Miki [1952] gives an estimate, based on a theoretical calculation, that the dynamic viscosity lies between 10 - and 10 - poise. Malkus [1968] suggests the range 10 -' to 1 poise. Attenuation of S waves reflected from the core [Sato and Espinosa, 1967b;

  18. Understanding Common Core State Standards

    ERIC Educational Resources Information Center

    Kendall, John S.

    2011-01-01

    Now that the Common Core standards are coming to just about every school, what every school leader needs is a straightforward explanation that lays out the benefits of the Common Core in plain English, provides a succinct overview, and gets everyone thinking about how to transition to this promising new paradigm. This handy, inexpensive booklet…

  19. The Common Core Takes Hold

    ERIC Educational Resources Information Center

    Rothman, Robert

    2014-01-01

    A survey administered in the spring of 2013 by the Center on Education Policy (CEP) inquired into the implementation of Common Core State Standards at that time. Based on self-reports by state officials, the survey found that curricula aligned to the common core were already being taught in at least some districts or grade levels. All states…

  20. Energetics of the earth's core

    Microsoft Academic Search

    D. Gubbins

    1977-01-01

    In view of recent evidence that the core contribution to the heat flux through the earth's surface is well below that required to maintain a dynamo for the earth's observed magnetic field, the release of gravitational energy as a result of chemical differentiation in the core is investigated as an alternative driving mechanism. It is shown that the gravitational energy

  1. Experimental Constraints on Core Composition

    Microsoft Academic Search

    J. Li; Y. Fei

    2003-01-01

    The Earth's core was discovered in 1906, when Oldham inferred the existence of a low-velocity region inside the Earth from changes in the amplitude of compressional waves traveling through the Earth's interior (Oldham, 1906). Over the last century, a wealth of knowledge has been obtained on the nature and dynamics of the core ( Figure 1; Dziewonski and Anderson, 1981;

  2. Viscosity of the earth's core

    NASA Technical Reports Server (NTRS)

    Hide, R.

    1972-01-01

    Estimates of the coefficient of kinematical viscosity nu of the earth's liquid metallic core that are given in the geophysical literature range from approximately 0.001 sq cm/s, the viscosity of molten iron at ordinary pressures, to approximately less than 10 to the 8th power sq cm/s, based on the observation that compressional waves traverse the core without suffering serious attenuation. Bumps on the core-mantle boundary with typical horizontal dimensions up to a few thousand km and vertical dimensions h of a few km would produce the topographic coupling between the core and mantle that is evidently implied by the observed decade variations in the length of the day (unless the coupling is due to the presence of rapidly fluctuating magnetic fields in the core).

  3. Comparing the Common Core State Standards in Mathematics and Japan's Mathematics Curriculum in the Course of Study. Achieving the Common Core

    ERIC Educational Resources Information Center

    Achieve, Inc., 2010

    2010-01-01

    Through the Common Core State Standards (CCSS) Initiative, states and territories have collaborated in the development of a common core of standards in English Language Arts and mathematics for grades kindergarten through twelve that are now being adopted by states. Designed not only for the purpose of providing strong, shared expectations, the…

  4. Electron Abundance in Protostellar Cores

    E-print Network

    Paolo Padoan; Karen Willacy; William Langer; Mika Juvela

    2004-06-23

    The determination of the fractional electron abundance, Xe, in protostellar cores relies on observations of molecules, such as DCO+, H13CO+ and CO, and on chemical models to interpret their abundance. Studies of protostellar cores have revealed significant variations of Xe from core to core within a range 10^-8core age, extinction and density. We compute numerically the intensity of the radiation field within a density distribution generated by supersonic turbulence. Taking into account the lines of sight in all directions, the effective visual extinction in dense regions is found to be always much lower than the extinction derived from the column density along a fixed line of sight. Dense cores with volume and column densities comparable to observed protostellar cores have relatively low mass-averaged visual extinction, 2mag <= A_V <= 5mag, such that photo-ionization can sometimes be as important as cosmic ray ionization. Chemical models, including gas-grain chemistry and time dependent gas depletion and desorption, are computed for values of visual extinction in the range 2mag <= A_V <= 6mag, and for a hydrogen gas density of 10^4cm^-3$, typical of protostellar cores. The models presented here can reproduce some of the observed variations of ion abundance from core to core as the combined effect of visual extinction and age variations. The range of electron abundances predicted by the models is relatively insenstive to density over 10^4 to 10^6 cm^{-3}.

  5. Core compressor exit stage study, 2

    NASA Technical Reports Server (NTRS)

    Behlke, R. F.; Burdsall, E. A.; Canal, E., Jr.; Korn, N. D.

    1979-01-01

    A total of two three-stage compressors were designed and tested to determine the effects of aspect ratio on compressor performance. The first compressor was designed with an aspect ratio of 0.81; the other, with an aspect ratio of 1.22. Both compressors had a hub-tip ratio of 0.915, representative of the rear stages of a core compressor, and both were designed to achieve a 15.0% surge margin at design pressure ratios of 1.357 and 1.324, respectively, at a mean wheel speed of 167 m/sec. At design speed the 0.81 aspect ratio compressor achieved a pressure ratio of 1.346 at a corrected flow of 4.28 kg/sec and an adiabatic efficiency of 86.1%. The 1.22 aspect ratio design achieved a pressure ratio of 1.314 at 4.35 kg/sec flow and 87.0% adiabatic efficiency. Surge margin to peak efficiency was 24.0% with the lower aspect ratio blading, compared with 12.4% with the higher aspect ratio blading.

  6. Parallel Architecture Core (PAC)--the First Multicore Application Processor SoC in Taiwan Part I: Hardware

    E-print Network

    Hung, Shih-Hao

    compiler has also been developed for PACDSP. A dual- core PAC SoC has been designed and fabricated, which consists of a PACDSP core, an ARM9 core, scratchpad memories, and various on-chip peripherals Taiwan University, Taipei, Taiwan J Sign Process Syst DOI 10.1007/s11265-010-0470-0 #12;players and smart

  7. Dislocation core energies and core fields from first principles.

    PubMed

    Clouet, Emmanuel; Ventelon, Lisa; Willaime, F

    2009-02-01

    Ab initio calculations in bcc iron show that a 111 screw dislocation induces a short-range dilatation field in addition to the Volterra elastic field. This core field is modeled in anisotropic elastic theory using force dipoles. The elastic modeling thus better reproduces the atom displacements observed in ab initio calculations. Including this core field in the computation of the elastic energy allows deriving a core energy which converges faster with the cell size, thus leading to a result which does not depend on the geometry of the dislocation array used for the simulation. PMID:19257518

  8. Feasibility study of boiling water reactor core based on thorium–uranium fuel concept

    Microsoft Academic Search

    Alejandro Núñez-Carrera; Juan Luis François Lacouture; Cecilia Martin del Campo; Gilberto Espinosa-Paredes

    2008-01-01

    The design of a boiling water reactor (BWR) equilibrium core using the thorium–uranium (blanket–seed) concept in the same integrated fuel assembly is presented in this paper. The lattice design uses the thorium conversion capability to 233U in a BWR spectrum. A core design was developed to achieve an equilibrium cycle of one effective full power year in a standard BWR

  9. Advances in core loss calculations for magnetic materials

    NASA Technical Reports Server (NTRS)

    Triner, J. E.

    1982-01-01

    A new analytical technique which predicts the basic magnetic properties under various operating conditions encountered in state-of-the-art dc-ac/dc converters is discussed. Using a new flux-controlled core excitation circuit, magnetic core characteristics were developed for constant values of ramp flux (square wave voltage excitation) and frequency. From this empirical data, a mathematical loss characteristics equation is developed to analytically predict the specific core loss of several magnetic materials under various waveform excitation conditions. In addition, these characteristics show the circuit designer for the first time the direct functional relatonships between induction level and specific core loss as a function of the two key dc-dc converter operating parameters of input voltage and duty cycle.

  10. Summary of multi-core hardware and programming model investigations

    SciTech Connect

    Kelly, Suzanne Marie; Pedretti, Kevin Thomas Tauke; Levenhagen, Michael J.

    2008-05-01

    This report summarizes our investigations into multi-core processors and programming models for parallel scientific applications. The motivation for this study was to better understand the landscape of multi-core hardware, future trends, and the implications on system software for capability supercomputers. The results of this study are being used as input into the design of a new open-source light-weight kernel operating system being targeted at future capability supercomputers made up of multi-core processors. A goal of this effort is to create an agile system that is able to adapt to and efficiently support whatever multi-core hardware and programming models gain acceptance by the community.

  11. In-core detector activation rate for a PWR assembly

    SciTech Connect

    Todosow, M.; Eisenhart, L.D.

    1982-01-01

    The in-core detector system is the principal source of information for determining relative assembly powers, and maximum fuel rod powers in a reactor core. The detector signals are used in conjunction with pre-calculated factors, and appropriate normalizations, to obtain measured power values. Considerable reliance is placed on the accuracy of in-core detector inferred power distributions in reactor operations, and in the verification of calculational methods. The objective of this study was to compare results from standard design codes for the in-core detector activation rate (and the fission rate distribution in an assembly), to results obtained from a detailed calculation performed with a continuous energy Monte Carlo program with ENDF/B-V nuclear data.

  12. Foam core materials for structural sandwich panels

    SciTech Connect

    Huang Jongshin.

    1991-01-01

    The author first investigates the creep of polymer foam cores. Models for the creep of linear and nonlinear viscoelastic polymer foams are proposed. Experimental results for the creep of a rigid polyurethane foam are compared to the mode; agreement is good. The results indicate that creep can limit the design of building panels with polymer foam cores. Next, he studies the potential of using ceramic foams as a core material in building panels. Ceramic foams have a high stiffness, high creep resistance, low cost, and are incombustible. Ceramic foams, however, have a low fracture toughness and tensile strength. Assuming that the variability of cell wall modulus of rupture follows a Weibull distribution, there is a cell size effect on both the fracture toughness and tensile strength. Both the tensile strength and fracture toughness of ceramic foams can be improved by controlling the cell size. Since cell wall deformation of cellular materials is primarily by bending, the mechanical properties of cellular materials may be improved by making cell walls into sandwich structures. Hollow-sphere composites are made by introducing thin-walled hollow spheres into a matrix.

  13. Uncovering the information core in recommender systems

    PubMed Central

    Zeng, Wei; Zeng, An; Liu, Hao; Shang, Ming-Sheng; Zhou, Tao

    2014-01-01

    With the rapid growth of the Internet and overwhelming amount of information that people are confronted with, recommender systems have been developed to effectively support users' decision-making process in online systems. So far, much attention has been paid to designing new recommendation algorithms and improving existent ones. However, few works considered the different contributions from different users to the performance of a recommender system. Such studies can help us improve the recommendation efficiency by excluding irrelevant users. In this paper, we argue that in each online system there exists a group of core users who carry most of the information for recommendation. With them, the recommender systems can already generate satisfactory recommendation. Our core user extraction method enables the recommender systems to achieve 90% of the accuracy of the top-L recommendation by taking only 20% of the users into account. A detailed investigation reveals that these core users are not necessarily the large-degree users. Moreover, they tend to select high quality objects and their selections are well diversified. PMID:25142186

  14. Uncovering the information core in recommender systems.

    PubMed

    Zeng, Wei; Zeng, An; Liu, Hao; Shang, Ming-Sheng; Zhou, Tao

    2014-01-01

    With the rapid growth of the Internet and overwhelming amount of information that people are confronted with, recommender systems have been developed to effectively support users' decision-making process in online systems. So far, much attention has been paid to designing new recommendation algorithms and improving existent ones. However, few works considered the different contributions from different users to the performance of a recommender system. Such studies can help us improve the recommendation efficiency by excluding irrelevant users. In this paper, we argue that in each online system there exists a group of core users who carry most of the information for recommendation. With them, the recommender systems can already generate satisfactory recommendation. Our core user extraction method enables the recommender systems to achieve 90% of the accuracy of the top-L recommendation by taking only 20% of the users into account. A detailed investigation reveals that these core users are not necessarily the large-degree users. Moreover, they tend to select high quality objects and their selections are well diversified. PMID:25142186

  15. Opportunities Beyond Single-Core Microprocessors

    E-print Network

    Hill, Mark D.

    Opportunities Beyond Single-Core Microprocessors HPCA/PPOPP 2009 Panel Mark D. Hill U. of Wisconsin Set Architecture ­ Vacuum Tubes, Magnetic Core, Magnetic Disks, VLSI C t f i d 1011 i 55­ Cost chips here & cores multiplying fast!A: Multicore chips here & cores multiplying fast! 4 cores now 16

  16. Evolution of First Cores and Formation of Stellar Cores in Rotating Molecular Cloud Cores

    NASA Astrophysics Data System (ADS)

    Saigo, Kazuya; Tomisaka, Kohji; Matsumoto, Tomoaki

    2008-02-01

    We followed the collapse of cloud cores with various rotation speed and density frustrations using three-dimensional hydrodynamical simulations by assuming a barotropic equation of state and examined the comprehensive evolution paths from the rotation molecule cloud core to stellar core. We found that the evolutionary paths depend only on the angular velocity of initial cloud core ?c0. These evolutionary paths agree well with predictions of Saigo and Tomisaka's quasi-equilibrium axisymmetric models and SPH calculations of Bate. Evolutionary paths are qualitatively classified into three types. (1) A slowly rotating cloud with ?c0<0.01/tff=0.05(?c0/10-19 g cm-3)1/2 rad Myr-1 shows spherical-type evolution, where ?c0 is the initial central density. Such a cloud forms a first core which is mainly supported by the thermal pressure. The first core has a small mass of Mcore~0.01 Msolar and a short lifetime of a few ×100 yr. After exceeding the H2 dissociation density ?~=5.6×10-8 g cm-3, it begins the second collapse, and the whole of the first core accretes onto the stellar core/disk within a few free-fall timescales. (2) A rotating cloud with 0.01/tffcore becomes a centrifugally supported massive disk with Mcore~a few×0.01-0.1 Msolar and the lifetime is a few thousand years. The first core is unstable against nonaxisymmetric dynamic instability and forms spiral arms. The gravitational torque through spiral structure extracts angular momentum from the central region to the outer region of the first core. And only a central part with r~1 AU begins the second collapse after exceeding dissociation density. However, the outer remnant disk keeps its centrifugal balance after stellar core formation. It seems that this remnant of the first core should control the mass and angular momentum accretion onto the newborn stellar system. (3) A rotating cloud with 0.05/tff<~?c0 tends to fragment into binary or multiple during the first core phase.

  17. Exploring Two Phases of Design-by-Analogy "Multiple Solutions" and "Multiple Analogies" 

    E-print Network

    Gadwal, Apeksha

    2010-10-12

    Idea generation and design-by-analogy are core parts of design. Designers need tools to assist them in developing creative and innovative ideas. Analogy is one such tool that helps designers solve design problems. It is a ...

  18. Study on Ultra-Long Life,Small U-Zr Metallic Fuelled Core With Burnable Poison

    SciTech Connect

    Kenji Tsuji; Hiromitsu Inagaki; Akira Nishikawa [Chubu Electric Power Company Inc., 1, Higashi-shincho Higashi-ku, Nagoya-shi, ACH 461-8680 (Japan); Hisato Matsumiya; Yoshiaki Sakashita; Yasuyuki Moriki; Mitsuaki Yamaoka; Norihiko Handa [Toshiba Corporation (Japan)

    2002-07-01

    A conceptual design for a 50 MWe sodium cooled, U-Pu-Zr metallic fuelled, fast reactor core, which aims at a core lifetime of 30 years, has been performed [1]. As for the compensation for a large burn-up reactivity through 30 years, an axially movable reflector, which is located around the core, carries the major part of it and a burnable poison does the rest. This concept has achieved not only a long core lifetime but also a high discharged burn-up. On this study, a conceptual design for a small fast reactor loading U-Zr metallic fuelled core instead of U-Pu-Zr fuelled core has been conducted, based on the original core arrangement of 4S reactor [2]. Within the range of this study including safety requirements, adopting the burnable poison would be effective to construct a core concept that achieves both a long lifetime and a high discharged burn-up. (authors)

  19. (Plasmonic Metal Core)/(Semiconductor Shell) Nanostructures

    NASA Astrophysics Data System (ADS)

    Fang, Caihong

    Over the past several years, integration of metal nanocrystals that can support localized surface plasmon has been demonstrated as one of the most promising methods to the improvement of the light-harvesting efficiency of semiconductors. Ag and Au nanocrystals have been extensively hybridized with semiconductors by either deposition or anchoring. However, metal nanocrystals tend to aggregate, reshape, detach, or grow into large nanocrystals, leading to a loss of the unique properties seen in the original nanocrystals. Fortunately, core/shell nanostructures, circumventing the aforementioned problems, have been demonstrated to exhibit superior photoactivities. To further improve the light-harvesting applications of (plasmonic metal core)/(semiconductor shell) nanostructures, it is vital to understand the plasmonic and structural evolutions during the preparation processes, design novel hybrid nanostructures, and improve their light-harvesting performances. In this thesis, I therefore studied the plasmonic and structural evolutions during the formation of (Ag core)/(Ag2S shell) nanostructures. Moreover, I also prepared (noble metal core)/(TiO2 shell) nanostructures and investigated their plasmonic properties and photon-harvesting applications. Clear understanding of the sulfidation process can enable fine control of the plasmonic properties as well as the structural composition of Ag/Ag 2S nanomaterials. Therefore, I investigated the plasmonic and structural variations during the sulfidation process of Ag nanocubes both experimentally and numerically. The sulfidation reactions were carried out at both the ensemble and single-particle levels. Electrodynamic simulations were also employed to study the variations of the plasmonic properties and plasmon modes. Both experiment and simulation results revealed that sulfidation initiates at the vertices of Ag nanocubes. Ag nanocubes are then gradually truncated and each nanocube becomes a nanosphere eventually. The cubic shape is maintained throughout the sulfidation process, with the edge length being increased gradually. TiO2 is one of the most important semiconductors that are employed in light-harvesting applications. It has been extensively studied for a variety of applications by virtue of its low toxicity, biological compatibility, chemical and thermal stability, resistance to photocorrosion, and relative abundance. However, the photocatalytic activity of TiO2 is limited to the UV region because of its wide band gap, which limits its applications in light harvesting. Although (Au core)/(TiO2 shell) nanostructures can improve the photocatalytic activities of TiO2 in visible light, it has only been demonstrated in a few experiments and has been limited with Au nanospheres. Compared with Au nanospheres, Au nanorods offer more attractive plasmonic features, including stronger electric field enhancements and synthetically tunable longitudinal plasmon wavelengths over the visible to near-infrared region. The coating of Au nanorod therefore can largely improve light harvesting capability of TiO2. In this thesis, I developed a facile and versatile method for the preparation of (Au nanocrystal core)/(TiO2 shell) nanostructures by using a Ti(III) compound as the titania precursor. By employing Au nanorods with different sizes and varying the shell thickness, the plasmonic bands of the core/shell nanostructures can be tailored. TiO2 can also be grown on other monometallic and bimetallic Pd, Pt, Au nanocrystals. As a proof-of-concept application, (Au nanorod core)/(TiO2 shell) nanostructures were utilized in dye-sensitized solar cells to function as a scattering layer. The resultant solar cells exhibited higher power conversion efficiencies with a thinner thickness compared to the traditional TiO 2 solar cells. In addition, I also examined the property of plasmon-enhanced reactive oxygen species generation. Moreover, the TiO2 shell with a high refractive index can efficiently couple with the plasmon resonance modes of the Au nanorod core, leading to Fano resonances. Fano resonances for

  20. Design Model Design Model

    E-print Network

    van Sinderen, Marten

    Design Model 123 Chapter 6 Design Model This chapter presents a design model that allows refinement types are identified, and their relevance to design steps in the application protocol design, interaction and causality relation are the elementary design, or architectural, concepts of our design model